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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present regular United States Patent Application claims the benefits of U.S. Provisional Application Ser. No. 60/781,056 filed on Mar. 10, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates generally to fasteners and, more particularly, the invention pertains to fasteners such as weld nuts that are secured in assemblies for subsequent engagement by a complementary fastener component such as a bolt or stud.
BACKGROUND OF THE INVENTION
[0003] It is known to use so-called weld nuts as part of fastener systems in a variety of installations and assemblies. It is known to secure the weld nut in a fixed position for later engagement with the complementary component of the fastener system, particularly when it is difficult to access the location at which the nut is to be installed for completing the assembly. For example, it is known to use weld nuts in various locations on automobiles where components later secured thereto are positioned in a laid on assembly that covers the nut before the fastener is secured. Weld nuts are used also in installations in which the anchoring component is of insufficient thickness to be threaded for anchoring a fastener, such as a bolt, directly. Weld nuts are used also to improve speed and efficiency in later assembly, even when the nut is accessible in the subsequent assembly. For example, it is known to provide a two-piece weld nut in which a weld plate is provided with a round hole and a nut includes a collar or hub secured in the hole. The nut and weld plate are rotatable relative to one another.
[0004] Weld nuts have worked satisfactorily for these and other installations, but are not without deficiencies. For example, in blind installations wherein the nut is not accessible as the assembly is being completed, it is necessary for the nut to be secured and not rotatable relative to the weld plate. The aforedescribed two piece weld nut assembly in which the nut and plate are rotatable relative to each other is not suitable for such installations. For these installations, other types of weld nuts have been used. For example, a weld nut can be made from a single, monolithic piece of material including the threaded fastener component and a plate-like component by which the weld nut is anchored in the assembly. However, techniques used for shaping a nut and a weld plate from a single piece of material have been expensive and wasteful of material. Other structures also have been used, including two piece weld nut assemblies in which one or more nut is welded to a weld plate which is subsequently welded in the assembly. Again, manufacturing techniques for weld nuts of this type can be time consuming and expensive.
[0005] It is known also to provide a plurality of projections or weld nibs on the surface of the weld nut which is to confront the anchoring or supporting material. The weld nut is then secured to the supporting material by resistance welding, which causes the projections to flow and alloy with the supporting material. It can be difficult to see if acceptable alloying has occurred in that the weld nibs are beneath the plate. Also, flash from the welding process can contact threaded portions of the weld nut, causing thread damage and difficult subsequent engagement with a bolt or other threaded component attached thereto. If the welds are not secure, or if the fastening system is subjected to excessive torque or other forces, the weld zones can break loose, allowing the weld nut to spin when the complementary fastener portion is connected thereto or disconnected therefrom. Excessive force conditions as described can occur particularly if weld flash during the attachment of the weld nut has come in contact with the threads of the weld nut, thereby increasing torque requirements to thread the bolt into the weld nut. Excessive force conditions also can occur if the thread on the weld nut is malformed or damaged during handling and installation.
SUMMARY OF THE INVENTION
[0006] The present invention provides a two piece weld nut in which simple stamping processes are used to engage the nut and weld plate to restrain relative axial movement therebetween, and wherein an interface between the nut and weld plate is configured to prevent relative rotation between the weld nut and weld plate.
[0007] In one aspect thereof, the present invention provides a fastener assembly with a plate defining a hole and a fastener having a hub disposed in the hole. The hub is secured in the hole, and the plate and the fastener are substantially immovable axially one relative to the other. The plate and the fastener have confronting surfaces establishing an interface between the plate and the fastener, the confronting surfaces including complementary configurations interfering one with the other in either direction of relative rotation between the plate and the fastener with the hub in the hole.
[0008] In another aspect thereof, the present invention provides a weld nut with a nut having a body with a threaded bore and a hub extending axially from the body. The hub is narrower than the body and the body has an end surface radially outward of the hub. A first set of contours is provided on the end surface of the body. A plate has a hole and a nut facing surface. A second set of contours is provided on the nut facing surface of the plate. The hub is secured in the opening, and the nut and the plate are substantially immovable axially one relative to the other. The first and second contours internest one with the other, the contours abutting one against the other to limit relative rotational movement between the nut and the plate.
[0009] In a still further aspect thereof, the present invention provides a fastener assembly with a threaded body having an end surface and a hub extending axially from the end surface of the body. The end surface outwardly of the hub defines alternating ridges and valleys. A plate has a hole, and the hub is disposed in the hole and secured to the plate in a manner to constrain relative axial movement between the body and the plate. A surface of the plate defines a second set of alternating valleys and ridges internested with the ridges and the valleys of the end surface.
[0010] An advantage of the present invention in one form thereof is providing a weld nut that can be manufactured in a cost efficient manner.
[0011] Another advantage of a form of the present invention is providing a weld nut having weld nibs remotely located relative to the threads of the weld nut, to reduce potential for thread damage resulting from weld flash contacting the threads when the weld nut is installed in an assembly.
[0012] A further advantage of a form of the invention is providing a weld nut as a two piece assembly so that the nut and weld plate portions thereof can be provided of different materials.
[0013] A still further advantage of a form of the present invention is providing a weld nut in which the nut and weld plate thereof are rotationally secured, one with respect to the other so that relative rotation between the nut and weld plate portions are inhibited.
[0014] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a two piece weld nut in accordance with the present invention;
[0016] FIG. 2 is a perspective view of another form of a weld nut of the present invention, illustrating a bottom of the weld nut;
[0017] FIG. 3 is a perspective view of the nut portion for the weld nuts shown in the preceding drawings;
[0018] FIG. 4 is a cross-sectional view of the weld nut shown in FIG. 2 ;
[0019] FIG. 5 is a perspective view similar to that of FIG. 1 , but illustrating another modified form of the present invention;
[0020] FIG. 6 is an exploded view of another embodiment of the present invention;
[0021] FIG. 7 is an exploded view of yet another embodiment for a two piece weld nut of the present invention;
[0022] FIG. 8 is an exploded view of a further embodiment for a two piece weld nut of the present invention; and
[0023] FIG. 9 is an exploded view of still another embodiment for a two piece weld nut of the present invention.
[0024] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring now more specifically to the drawings, and to FIG. 1 in particular a fastener assembly in the form of a weld nut 10 in accordance with the present invention is shown. Weld nut 10 is a two piece assembly including a fastener such as a nut 12 and a weld plate 14 . Weld nut 10 can be made of a variety of materials including metals and the like. An advantage of certain forms of the present invention is that nut 12 and weld plate 14 can be provided from different materials. Accordingly, nut 12 can be made of material advantageous for the fastening function, such as brass or other costly material, and weld plate 14 can be made of a lesser expensive material, such as steel, more suited for welding attachment within the assembly.
[0026] Nut 12 includes a main body 16 having an axial opening therethrough defining a thread 18 for engagement with a complementary threaded stud, bolt or the like (not shown). A hub 20 , best seen in FIG. 3 , extends axially away from one end surface 22 of body 16 . Hub 20 is narrower than body 16 such that end surface 22 extends radially outwardly relative to hub 20 . In the illustrated embodiment shown in FIGS. 1-5 , hub 20 has a round periphery and has a tapered inner surface 24 whereby a distal end edge 26 of hub 20 is thinner than portions of hub 20 closer to body 16 .
[0027] End surface 22 is provided with a first set of contours including alternating ridges 28 and valleys 30 . In the illustrated embodiment, ridges 28 and valleys 30 extend substantially radially outwardly along end surface 22 . Ridges 28 and valleys 30 are substantially square cut, such that the bottoms of valleys 30 are flat and the tops of ridges 28 are flat, with substantially flat sides 32 that are substantially perpendicular to the flat upper surface of an adjacent ridge 28 and the flat bottom surface of an adjacent valley 30 .
[0028] Weld plate 14 in the exemplary embodiment is a substantially flat, washer-like body, although other shapes and configurations can be used also. FIG. 1 illustrates a round weld plate 14 having a nut facing surface 40 . Weld plate 14 defines a hole 42 configured for receiving hub 20 therein. As illustrated in FIG. 4 , hole 42 can include a tapered surface 44 expanding outwardly away from surface 40 . Hole 42 also can define an undercut 46 and a diametrically larger opening at a surface opposite nut facing surface 40 .
[0029] Nut facing surface 40 defines a second set of contours including valleys 48 and ridges 50 shaped and arranged to complement ridges 28 and valleys 30 whereby each are received one within the other in a nested arrangement. Accordingly, ridges 28 are received in valleys 48 and ridges 50 are received in valleys 30 . Accordingly, valleys 48 and ridges 50 extend radially outwardly from hole 42 over nut facing surface 40 . Depending on the overall size of weld plate 14 , valleys 48 and ridges 50 need not extend completely to the outer edge of weld plate 14 so long as each are of sufficient length for complete nesting with ridges 28 and valleys 30 of nut 12 . Valleys 48 and ridges 50 are square cut similarly to that described previously for ridges 28 and valleys 30 . Accordingly, nut facing surface 40 is provided with substantially flat bottoms for valleys 48 and substantially flat tops for ridges 50 , with substantially flat sides 52 perpendicular to the adjacent valleys 48 and ridges 50 .
[0030] In an assembled weld nut 10 , hub 20 is inserted into hole 42 and ridges 28 and valleys 30 of end surface 42 are nested into valleys 48 and ridges 50 of nut facing surface 40 . Hub 20 is expanded, crushed, deformed or otherwise manipulated to secure hub 20 in hole 42 , whereby relative axial movement between nut 12 and weld plate 14 is constrained. Manipulation of hub 20 to secure it in hole 42 can be performed by pressing, as those skilled in the art will readily understand. The thinner wall along surface 24 toward distal end edge 26 can facilitate outward expansion of hub 20 . Portions of end edge 26 can be expanded into undercut 46 , to secure relative axial positioning of nut 12 and weld plate 14 .
[0031] Nut 12 and weld plate 14 are held tightly one against the other such that the interface of end surface 22 and nut facing surface 40 includes the nesting of ridges 28 in valleys 48 and ridges 50 in valleys 30 . Relative rotation between nut 12 and weld plate 14 is thereby restricted in both directions. The substantially square cut configurations of ridges 28 , valleys 30 , ridges 48 and valleys 50 establish torque resistance to relative rotation between nut 12 and weld plate 14 .
[0032] Whereas weld plate 14 in the embodiments illustrated in FIGS. I and 5 is substantially round, it should be understood that other configurations also can be used. For example, the embodiment of FIG. 2 includes a weld plate 60 having a hex shaped perimeter.
[0033] Weld nibs 62 are provided for securing weld nuts of the present invention on the supporting body (not shown). FIG. 1 illustrates an embodiment having three weld nibs 62 . FIG. 2 and FIG. 5 illustrate embodiments having more weld nibs 62 . The number, location and spacing for weld nibs 62 can be selected for advantageous installation and attachment on the supporting structure. Weld nibs 62 are provided at the outer edge of the weld plate. Accordingly, flash that may occur during the installation process is more distantly located from thread 18 , thereby reducing the risk for damage to thread 18 from contact with the weld flash. Further, with the bonding or alloying performed at more distant locations from the center axis of the weld nut assembly, greater torque resistance is provided to reduce the risk of the weld nut being dislodged from its installed position. Further, in some situations, weld nibs 62 at the perimeter of the weld plate can allow for visual inspection of the weld integrity during installation.
[0034] In the embodiments thus far described, the interface between nut 12 and weld plate 14 or 60 is established along a substantially radial plane relative to the axis of the weld nut. Accordingly, hub 20 of nut 12 and hole 42 of the weld plate can be round, and. Thus, precise rotational orientation of the nut with respect to the weld plate during assembly is not required. With relatively narrow ridges and valleys, as pressing is performed to secure nut 12 in weld plate 14 or 60 , the ridges and valleys are drawn into the required nesting relationship.
[0035] It should be understood that other configurations for an interfering relationship between the interface of a nut and weld plate also can be used. For example, an outer surface of the hub and the hole in the weld plate can be complementarily shaped to restrict relative rotation between the nut and weld plate. FIG. 6 illustrates a weld nut 70 including a nut 72 and a weld plate 74 . Nut 72 includes a hex-shaped hub 76 , and weld plate 74 defines a complementary hex-shaped hole 78 .
[0036] In FIG. 7 , a weld nut 80 includes a nut 82 and a weld plate 84 . A hub 86 of nut 82 includes a spline-like configuration of alternating ridges and valleys, and weld plate 84 defines a complementarily notched opening 88 for engaging the spline configuration of hub 86 .
[0037] FIG. 8 illustrates a weld nut 90 including a nut 92 and a weld plate 94 . A hub 96 is shaped similarly to a gear, and a hole 98 of weld plate 94 is complimentarily shaped for receiving hub 96 .
[0038] FIG. 9 illustrates a still further embodiment of the present invention in which a nut plate 100 includes a nut 102 and a weld plate 104 . A hub 106 of nut 102 is oval in shape, and weld plate 104 defines an oval hole 108 for receiving hub 106 .
[0039] The attachment of nuts 72 , 82 , 92 and 102 in weld plates 74 , 84 , 94 and 104 , respectively, can be performed by manipulation of the hubs as described previously. However, it should also be understood that any of the various hubs described herein, as well as other variations thereof, also can be secured in an appropriate weld plate opening by a press-fit or interference fit of the hub in the opening, without substantial alteration of the hub.
[0040] Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
[0041] Various features of the invention are set forth in the following claims. | A weld nut includes a separate nut and a separate weld plate engaged one with the other to constrain relative axial movement of one with respect to the other. Confronting surfaces along an interface of the nut and weld plate are configured to interfere one with the other and constrain relative rotational movement between the nut and weld plate. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a door opening mechanism and more particularly to a door opener which is particularly adapted to be employed in a trash receptacle having a swinging access door. Accordingly, when it is desired to deposit trash in the trash receptacle, the user merely moves a handle mounted on the outside of the receptacle a short distance and the pivotally mounted door is moved to an open position. After the trash is deposited in the receptacle, the user merely releases the handle and the door swings to its closed position.
In many business establishments and particularly in fast food establishments, trash receptacles are provided with a swinging door positioned near the top of the receptacle. Experience has shown that it is difficult to dispose of trays of cups, food wrappers, and food since the door tends to swing down against the trash preventing it from being easily deposited into the receptacle. A customer carrying a briefcase or other object has even a more difficult time in attempting to properly dispose of waste or trash.
Accordingly, a primary object of the invention is to provide an improved exteriorly actuated door opening means.
Another object is to provide a door on a trash receptacle which is actuated by the user by merely moving an exteriorly mounted handle a distance and whereby the user can easily hold the door in a fully open position until trash is deposited in the receptacle.
A still further object is to provide a door opening mechanism which, except for an exteriorly mounted handle, is fully concealed at the top of the inside of the receptacle and allows the door to be opened to its maximum extent. Another object is to provide a door opening mechanism for a trash receptacle which minimizes the likelihood of the users hands being sailed by the refuse when depositing the same in the receptacle.
SUMMARY OF THE INVENTION
The user actuated door opening assembly of the present invention is ideally suited for use in a trash housing or receptacle for opening the swinging access door by moving an exteriorly mounted handle The user can hold the door in a fully open position until the trash is deposited. Except for an exposed handle, the door opening assembly is fully concealed within the housing and does not interfere with opening or closing the door.
In a trash housing where the door is positioned in the upper portion of a side wall of the housing, the door opening assembly is positioned in the interior of the housing and above the top edge of the door and below the top of the housing. The assembly preferably includes a rigid plate mounting fastened to the underside of the top of the housing in such a manner that there is space between the mounting plate and the top of the housing. A link bar is pivotally mounted on the top side of the plate and extends to the exterior of the housing and just above the top edge of the door. Means for connecting the link bar and the door are mounted to the underside of the mounting plate whereby lateral movement of the link bar causes the door to swing into the interior of the housing to an open position.
In a further embodiment of the invention, a pair of link bars are employed, each of which are pivotally mounted to the mounting plate. Means are provided to connect the link bars in such a manner that lateral movement of either of the link bars in a direction will cause lateral movement of the other link bar in an opposite direction and cause the door to swing to an open position.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the instant invention will become readily apparent to those skilled in the art from the following detailed description of preferred embodiments thereof, taken in conjunction with the drawings in which:
FIG. 1 is a perspective view of a portion of a trash receptacle with a pivotally mounted door positioned in the upper portion of the receptacle and in a closed position;
FIG. 2 is a perspective view of a portion of a trash receptacle with a pivotally mounted door in the upper portion of the receptacle and in an open position;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1 and showing the door opening mechanism;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 3;
FIGS. 6 and 7 are perspective views of a portion of a trash receptacle showing a modified door opening mechanism which is provided with two externally mounted handles; and
FIG. 8 is a sectional view taken along the line 8--8 of FIG. 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIGS. 1 and 2 there is shown a typical trash receptacle housing 10 with a door 12 pivotally mounted by means of hinge pins 13 in a side wall 14 of the housing and near the top thereof. Positioned immediately above the top edge of door 12 is handle 16 fastened to a link bar 18 by means of screw 19. In FIG. 1 door 12 is in a closed position. In FIG. 2 the handle 16 and link bar 18 have been moved a distance laterally from its position shown in FIG. 1 and door 12 has swung into the interior of receptacle housing 10, or in an open position.
As best shown in FIG. 3 the door opening assembly or mechanism shown generally at 20 is positioned in the interior of housing 10 just below the top 11 of the housing and attached to mounting plate 22 which is formed of sheet steel or other rigid material. Mounting plate 22 is fastened to the underside of top 11 of the housing by means of screws 23 and at a distance from the underside of the top of the housing so that sufficient space 24 is provided for lateral movement of link bar 18. Link bar 18 is mounted to the surface of plate 22 which is nearest the underside of the top 11 of housing 10 for lateral movement by means of fastener 25. Mounted on the opposite side of plate 22 is a flexible cable or wire shown generally at 26 which is provided with a sheath 29 for most of its length. End 27 of cable 26 is mounted to the upper portion of the inside of door 12, with its opposite end 28 fastened to link bar 18. Lateral movement of link bar 18 to the right as shown by the directional arrow in FIG. 3 causes door 12 to be pulled upwardly towards the underside of the top of housing 10. This upward movement or opening of door 12 is accomplished by link bar 18 and cable 26. The end 27 of cable 26 is fastened to door 12 as follows. Mounted on the inside of door 12 and near its top edge is, inside view, a generally U-shaped bracket 30, the front surface 31 of which is provided with slot 32. Mounted at cable end 27 is ball 33 which fits into bracket 30. End 27 of cable 26 is positioned in slot 32 of bracket 30. The opposite end 28 of cable 26 is attached to link bar 18 by means of flat headed fastener 34. As best shown in FIG. 5, the flat head of fastener 34 is in the space 24 between the top of mounting plate 22 and the underside 11 of housing 10. The shank of flat headed fastener 34 is goes through opening 36 in mounting plate 18 and a portion thereof is exposed on the underside of link bar 18. End 28 of cable 26 is attached to shank 35 of fastener 34 in an appropriate manner.
In order to permit lateral movement of link bar 18 with its flat headed fastener mounted thereto, plate 22 is provided with a generally rectangular shaped opening 36. The opening is positioned in the mounting plate so that link bar 18 may be moved a distance laterally sufficient to move door 12 to a fully opened position.
As previously mentioned, the door opening assembly with the exception of link bar 18 is positioned on the underside of mounting plate 22 and in the area where door 12 swings to an open position. To avoid having the assembly interfere with the movement of the door, it is preferred to employ hold down brackets 38 and 38A to secure the cable portion of the assembly to the bottom of mounting plate 22 As shown in FIG. 3 such a bracket is used at each end of flexible cable 26. At end 28, bracket 38A surrounds cable 26 in its sheath 29 and is then fastened to the mounting plate. At cable end 27, bracket 38 is used to similarly secure cable 26 to the mounting plate. However, since bracket 30 mounted on door 12 is not in the same plane as cable 26, it is preferable to mount end 27 of cable 26 to the mounting plate as shown best in FIG. 4. This can be readily accomplished by making a U-shaped cut through the mounting plate and then bending the cut portion 40 of the mounting plate downwardly and thereafter fastening this end 27 of the cable to portion 40 of the mounting plate.
A further embodiment of the invention is shown in FIGS. 6-8 wherein a pair of link bars with attached handles are employed to open and close the door to the trash housing. FIG. 6 shows door 12 in a closed position. The user may grasp either of handles 16 or 16A and lateral movement of either handle and its attendant link bar 18 or 18A causes the lateral movement of the other handle and link bar. Thus as shown in FIGS. 6-8, lateral movement of handle 16 and link bar 18 in the direction shown by the arrow in FIG. 7 and FIG. 8 causes handle 16A and link bar 18A to move in an opposite direction and causing door 12 to open. The same action occurs if handle 16A is moved in a lateral direction as shown in FIGS. 7 and 8; that is handle 16 and link bar 18 also move laterally in a direction opposite to that of handle 16A and the door 12 is opened.
As shown in FIG. 8, this action is accomplished through the use of a pair of connector bars and an intermediate connector bar which join link bars 18 and 18A in such a manner that lateral movement of one of the link bars causes the other link bar to also move laterally, but in an opposite direction. A pair of link bars 18 and 18A with their handles 16 and 16A respectively are mounted to the mounting plate 22 in the same manner as described for the embodiment of FIGS. 1-6 That is, the link bars with their handles are mounted to the top surface of plate 22, the surface nearest the underside of the top 11 of housing 10 by means of fasteners 25 and 25A. Each of the link bars is movable laterally in the space 24 between the underside of top 11 and the upper surface of mounting plate 18. The door opening assembly 20 with its cable 26 is mounted to the underside of mounting plate 22 and attached to door 12 and to either one of the two link bars, in this case to link bar 18A, again in the same basic manner as shown in the embodiments of FIGS. 1-6. Positioned between link bars 18 and 18A are connector bars 42 and 44 and intermediate connector bar 46. Connector bars 42 and 44 are mounted on the underside of mounting plate 22, that is on the same side of the plate where the cable portion of door opening assembly 20 is mounted. Intermediate connector bar 46 is mounted on the upper side of plate 22, that is the side of the plate where link bars 18 and 18A are mounted. One end of connector bar 42 is pivotally fastened to link bar 18 by means of fastener 48. In a like manner connector bar 44 is pivotally mounted to link bar 18A by means of fastener 50. The opposite ends of connector bars 42 and 44 are joined together by means of intermediate connector bar 46 using fasteners 52 and 54. Fastener 56 secures intermediate connector bar 46 to mounting plate 22 in such a manner that bar 46 is able to pivot Because of the fact that each of connector bars 42 and 44 are not on the same side of mounting plate 22 as link bars 18 and 18A, generally rectangular shaped openings 58 and 60 are provided in plate 22 to allow lateral movement of each of the link bars.
It will thus be seen that lateral movement of link bar 18 in the direction shown by arrows 6 and 7 in FIG. 8 causes connector bar 42 to move laterally in the same direction as shown by arrow 5 However, intermediate connector bar 46 partially rotates in a clockwise direction as shown by arrows 3 and 4 and causes connector bar 44 to move laterally in a direction opposite to that of connector bar 42 as shown by arrow 2 which in turn causes link bar 18A to move in a lateral direction, shown by arrow 1 which is opposite that of link bar 18. Thus, the user may grasp either of handles 16 or 16A and lateral movement of either handle will cause the door 12 to swing to an open position. Movement of either handle back to its resting position will then close door 12.
Various changes and modifications to the embodiments herein chosen for purposes for illustration will readily occur to those skilled in the art To the extent that such modifications and variations fo not depart from the spirit of the invention, they are intended to included within the scope thereof which is assessed only by a fair interpretation of the following claims.
Having fully described and disclosed the instant invention in such clear and concise terms as to enable those skilled in the art to understand and practice the same, the claimed invention is set forth below. | A link bar is pivotally mounted on the top side of a plate which is secured to the underside of the top of a receptacle. The bar terminates with a handle exterior of the receptacle immediately above a hinged door. A cable extends between the door and an intermediate location of the bar. In response to lateral movement of the lever, the door is caused to swing inwardly open. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application of application Ser. No. 10/482,072, filed Dec. 24, 2003; which was a §371 national stage of International application PCT/EP02/07025, filed Jun. 25, 2002; the application also claims the priority, under 35 U.S.C. §119, of German patent application No. 101 30 512.5, filed Jun. 25, 2001; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a device for cultivating and/or treating cells, especially a bioreactor. Furthermore, the invention relates to a device for pumping a fluid through a device for cultivating and/or treating cells, especially through a bioreactor.
[0003] A method and a device of the initially mentioned type is described in an older application of the inventor DE 199 35 643.2.
[0004] Meanwhile, it has been found that the formation of a cell layer and cell growth are clearly improved by putting cells under pressure. A known practical approach is to apply a mechanical force to a cell culture chamber, e.g. by a plunger, as described in U.S. Pat. No. 6,060,306. This implies not only high design requirements, but such load does not reflect in-vivo conditions due to the heterogeneous pressure distribution such obtained. The attempt made in U.S. Pat. No. 5,928,945 is to apply a mechanical force e.g. to cartilage cells chiefly via shear flow stress by means of a culture medium. But this is unphysiological, because no such perfusions are encountered e.g. in articulation areas. In U.S. Pat. No. 6,060,306, an apparatus is described in which a cartilage construct is moved within a culturing chamber like in a bellows by means of outer wall movements. A disadvantage to said movement processes is that the movement patterns impart high mechanical stress to the membrane structures. That causes the membranes to break after a few days and makes the products insterile and thus inappropriate for implantations.
[0005] Furthermore, due to the movement patterns permanently causing convex-concave deformations, the membranes can only generate punctual and thus inhomogeneously distributed pressure deformations. That causes oscillations to form in the culture medium zone and pressure heterogeneities to form in the biological tissues in the bioreactor.
[0006] A common characteristic of some of said devices is that the pressure loads are firmly integrated in the culture vessel as a type design. This includes e.g. the bioreactor according to Hoestrup et al. (Tissue Engineering Vol. 6, 1, 2000 pp 75-79) for vessels and heart valves. Such models are a sophisticated design and expensive to sell, because the pumping system, due to its integration in the bioreactor, must be shipped with the future bioimplant as a complete unit. There is no sterile separation from the pump head.
[0007] Alternating pressure sources are provided in several other systems such as in WO 97/49799, but not explained in more detail. U.S. Pat. No. 5,899,937 describes a system which can compress a liquid-filled bladder by means of an eccentric movement via a plunger and thus force the liquid out of the bag thereby creating a liquid flow. A bladder is also used in U.S. Pat. No. 5,792,603 (WO 97/49799). But the system comprises vessels leading with open ends into a culture chamber with thorough intermixing of intravascular and extravascular liquids. That is especially disadvantageous if different medium compositions are needed inside and outside the vessels, e.g. to be able to offer growth factors and chemotactic factors directionally. That prevents e.g. the induction of directed migration of myofibroblasts from the place of population towards the outsides and constitutes a significant disadvantage in the population process. Also, that prevents the locally specific repopulation with different cell populations. Another disadvantage is immediate pressure compensation, which makes it impossible to create different pressure profiles in the intravascular and extravascular spaces. In the bioreactor according to Laube et al., the valves are no longer movable already when high volume amplitudes are applied, because the outer walls of the valves need to be fixed to the housing by sewing.
[0008] However, the pulsatile or pulse-type flow is in most cases generated in a conventional way via a peristaltic pump such that the pressure amplitudes are rather low in terms of change in volume, show flat frequencies and also mean high stress loads for the hose during several weeks' operation due to the permanent kneading effect. This is true e.g. for Niklason et al., Science 4, 1999 vol 284 pp 489-492, or EP 0320 441.
[0009] Further devices are described e.g. in DE 199 15610 A1, which are suitable especially for vessels and heart valves.
BRIEF SUMMARY OF THE INVENTION
[0010] The task of the present invention is to provide a device without the above-described disadvantages. An object of the invention is to provide a possibility for generating physiological, homogeneously acting pressure and volume amplitudes equally in a volumetric flow of liquid. Specifically, an object of the invention is to make it possible to generate entirely homogeneous pressure relations in all areas also in the bioartificial tissue within the bioreactor. The device is to be variably adaptable to the pressure-volume compliance of the system to be perfused. The device is to be modular, small, weight-saving, reliable, of low energy consumption and able to be coupled or combined with any systems to be perfused and is to apply minimal mechanical stress or no mechanical stress at all to the volumetric flow so that it can be connected with blood or other stress-sensitive fluids with or without biological components such as cells or proteins. Another object of the invention is to achieve a high degree of parallelization in the smallest space to be obtained by miniaturizing the module and by the direct ability to be coupled to and integrated in any possible perfusion systems.
[0011] In the present description, the term fluid is meant to designate not only liquids, especially blood, nutrient solutions, oils, or technical solutions, but also gases.
[0012] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0013] Although the invention is illustrated and described herein as embodied in “device for pressurized perfusion especially for culturing and/or treating cells”, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0014] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0015] FIG. 1 shows a first embodiment of a device for pressurized perfusion according to the present invention,
[0016] FIG. 2 shows a second embodiment of a device for pressurized perfusion according to the present invention,
[0017] FIG. 3 shows a third embodiment of a device for pressurized perfusion according to the present invention,
[0018] FIG. 4 shows a fourth embodiment of a device for pressurized perfusion according to the present invention,
[0019] FIG. 5 shows a fifth embodiment of a device for pressurized perfusion according to the present invention,
[0020] FIG. 6 shows a sixth embodiment of a device for pressurized perfusion according to the present invention,
[0021] FIG. 7 shows an embodiment of a device for pumping fluids according to the present invention,
[0022] FIG. 8 shows another embodiment of a device for pumping fluids according to the present invention,
[0023] FIG. 9 shows another embodiment of a device for pumping fluids according to the present invention,
[0024] FIG. 10 shows another embodiment of a device for pumping fluids according to the present invention,
[0025] FIG. 11 shows another embodiment of a device for pumping fluids according to the present invention,
[0026] FIG. 12 shows another embodiment of a device for pumping fluids according to the present invention,
[0027] FIG. 13 a through 13 c show another embodiment of a device for pumping fluids according to the present invention,
[0028] FIG. 14 shows another embodiment of a device for pumping fluids according to the present invention,
[0029] FIG. 15 shows another embodiment of a device for pumping fluids according to the present invention,
[0030] FIG. 16 shows an embodiment of a device for pressurized perfusion according to the present invention,
[0031] FIG. 17 shows an embodiment of a device for pressurized perfusion according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] FIG. 1 shows a modular component, which is coupled to a bioreactor 3 . The module is composed of two valves 1 A and 1 B as well as of a piston 2 and is adaptable to the bioreactor via a sterile coupling and directly, as shown in FIG. 1 , integratable in the influence area. Both valves 1 A and 1 B open in the same direction, in FIG. 1 to the left, towards the bioreactor. This generates a volumetric flow which is introduced into the reactor area at a high amplitude and pressure curve. So it is possible to achieve the opening and closing of an implant placed in the bioreactor, e.g. an allogenic heart valve. Two-leaflet valves opening or closing passively from flow changes are especially suited for the valves 1 A and 1 B. Other non-return valves, such as balls in a conically tapered tube section, are also possible.
[0033] FIG. 1 shows the perfusion module in a sagitally directed form. The advantage is that the backward movement of the piston 2 across the opening of valve 1 A enhancedly causes the heart valve leaflet to close and thus also allows the bioreactor to be emptied. The forward movement of the piston 2 causes the valve 1 B to close and the valve 1 A to open with subsequent opening of the biovalve in the bioreactor. During the backward movement of the piston 2 , fluid or medium is taken in from the reservoir 4 thereby filling the chamber in the perfusion module. The latter is refilled in circuit. Pressure compensation is via a sterile filter 5 .
[0034] FIG. 5 shows that the changes in volume in the perfusion module can also be achieved by displacing a plate 6 , which can be moved alternately by means of compressed air or vacuum via two valves 7 A and 7 B. The advantage is that the classical and sophisticated piston technology is done away with. The latter also requires an additional outer motor as shown in FIG. 1 .
[0035] The device according to FIG. 2 is even compacter in construction, in which the movable plate 6 is a permanent magnet with a biocompatible or liquid-proof or non-erosive encapsulation with e.g. a plastic layer of silicone or Teflon 6 ′ able to simultaneously provide a sealing function. Also, a jacket with a further metal (e.g. titanium, highgrade steel) can be provided. A sealing ring of e.g. Teflon or silicone is combinable for this purpose. But what is essential is that an alternately attracting or repelling force field can be created on the permanent magnet by integration of a current coil used to alternately generate negative poles 7 ′ or positive poles 7 ″. As an alternative to using permanent magnets, it is possible to integrate paramagnetic particles in the plate 6 so that a yet better directionalization can be achieved with regard to the force field of coil 7 . But the advantage of the mechanical principle is that costly external motors or compressed air or vacuum systems like those as still described herein in combination with perfusion technology can be done away with. Only then, the entire module will become very small, because the force-generating module or module responding to external forces is integrated in the movement module. Just a current source and a conventional electronic control are needed.
[0036] FIG. 3 shows that the plate 6 can have its own integrated electric coil 8 , which is connected via an elastic cable connector to a current source 10 ′ and 10″ alternately polarized to 7 ′ and 7 ″.
[0037] FIG. 4 shows how a cartilage-cell/bone-cell bioreactor 12 is integrated in the circuit. Stem cell integration is also possible here. Due to the use of a stop valve 11 , a pressure increase coupled with a volumetric flow is realizable. This is particularly important for the differentiation of cartilage but also bone structures, as well as of combinations, e.g. by using pure-phase beta-tricalcium phosphates as a seeding basis.
[0038] FIG. 6 shows an integrative system in which the magnetic perfusion principle is integrated in a bioreactor for the production of cartilage structures. The advantage is that the construction of the system is simpler in terms of apparatus while maintaining controlled physiological pressure amplitudes and volumetric flows. In this case, the cell culture can be located in a removable insert 13 . The piston can be lowered down to the insert 13 so as to be able to apply also immediate mechanical pressure to the cartilage structures. In addition to that, the system thus is emptied entirely so that mixing processes in the culture system can be directly controlled in terms of volume in order to be able to define the growth factor concentrations in situ. For the removal of the insert, the bioreactor can be opened or closed at 14 by means of e.g. a rotary or a clamp-type lock.
[0039] FIG. 7 shows the use of a magnetic pumping mechanism for imparting movement to a membrane thereby creating a volumetric flow.
[0040] FIG. 8 shows the use of a magnetic pumping system for pumping liquids such as blood, aqueous solutions or gases without supplying a treatment module such as a cell culture system (e.g. a bioreactor). An application is e.g. extracorporal perfusion for heart-lung machines or for assisting liver transplantation operations after hepatectomy. Previous rotary pumps produce even volumetric flows, but their manufacture is very costly and sophisticated. Using the pumping principle according to the invention in extracorporal perfusion has the advantage of restituting physiological pressure amplitudes. They are important for preserving organ functions and cellular differentiation especially in longer-term use.
[0041] FIG. 9 shows a double-sided pumping chamber. The plate 16 moves in the chamber in an oscillating manner and each of the outlet openings 17 ′ and 17 ″, which are coupled to valves, is controlled in a direction opposite to the inlet openings 18 ′ and 18 ″. In the centre, there is again a movable plate with a permanent magnet, paramagnet, or a magnetismsensitive material, or an electric coil.
[0042] FIG. 10 shows the construction for a piston motor. In this case, the plate is supported the rollers 19 ′ through 19 ″″ and moves in a chamber. The inner surfaces of the chambers 20 ′ and 20 ″ are equipped with electric conductors, which via the rollers 20 ′ through 20 ″″ come in contact with the plate 6 , within which an electric coil is again located. The plate 6 is equipped with a rod, which transfers the force of movement like a piston towards the outside. This can be used in vehicles or as a substitute for classical combustion engines.
[0043] FIG. 11 represents the same principle as FIG. 10 , but this time both an extension direction and a compression direction are possible simultaneously for the pistons 21 and 21 ′. In this case, the electric magnetic fields in 22 and 23 can always be oriented in directions opposite to one another and the magnetic field in the plate (plunger) 6 remains unchanged. As an alternative, the field in 6 can constantly alternate with the fields in 22 and 23 remaining unchanged. The coil in the plate 6 is supplied with current, like in FIG. 10 , through the roller mechanism 19 ′- 19 ″″. FIG. 12 relates to how a permanent magnet is used in plate 6 .
[0044] FIG. 13 shows an embodiment in which the magnetic pumping mechanism located in an elastic tube, such as in a hose, is directly installed in the wall structures either as half-shells or as attachments to be fixed or to be integrated. The advantage is to provide a universal pumping module that is directly integratable in circuits or in hose or tube systems. In FIG. 13 a , half-shells 24 and 25 are shown, which are connected with the wall of the hose system through elastic plastic materials. Said materials can be composed of conventional elastic tapes or can also have a direct integration in the wall structure of the hose. Additional coils 26 and 27 can be installed on the outside in order to increase the pumping force. So the internally movable pump in combination with the passively movable valves 1 A and 1 B is a universally applicable pumping element.
[0045] The very gentle treatment of the internal perfusate also allows it to be installed in the body as a heart-assisting system in combination with a battery (internal) or a magnetic field, which is installed outside on the body (e.g. thorax). Force transmission inwards to the implant is not invasive and without mechanical stress for the body. For implants, it is wise to integrate permanent magnets or so-called paramagnets in (nano-)particle form in the wall structures of the hose implant in a way to be able to achieve a contraction of the hose volume by changing the external magnetic field direction. For this purpose, the external poles can be arranged controlaterally, i.e. in front of and behind the thorax. The FIGS. 13 b and c show how an external battery unit 28 , 29 is installed around a hose 27 with 2 movable plates 6 and 6 ′, which lead to passive changes of volume of the hose 6 (sic!, the translator).
[0046] In FIG. 14 , it is shown how magnetic or magnetizable rods 30 are integrated in the wall structure 31 of a hose 32 . A circumferentially installed electric coil generates an inner magnetic field causing passive changes in volume in hose 32 . The hose is surrounded by an electric coil 34 .
[0047] FIG. 15 shows an electric coil 34 integrated in the hose itself. There is an electric coil 33 installed on the outside.
[0048] Another simplification is the introduction or the elastic jacketing of a hose with an elastic coil 35 . Changing the electric flow directions will cause field changes and thus cause the elastic coil rings to attract or repel one another. The connection with the elastic hose leads to pumping processes, which can again be directionalized by passive valves.
[0049] FIG. 16 shows an example for parallelization. For this purpose, e.g. miniaturized pump modules 36 are placed on chambers 44 , which can contain cell cultures 45 . The volume in the chambers is equivalent to e.g. 200-500 .mu.l and contains primary cells in reconstructed tissue section cultures. The plate 37 , which can be attracted and repelled magnetically, can move up and down directionally in the pump module. A movement away from the cell culture chamber or from the reaction chamber 44 provided for reaction without cellular systems causes the valve 40 to open and fresh medium is introduced by way of volume increase into the reaction chamber 44 . The reversing movement increases the internal pressure in the reaction chamber and causes the valve 38 to open so that a volumetrically definable portion of the reaction chamber contents can be forced out. The advantage of this mixing process, e.g. in cell culture, is that portions of the cytokines and growth factors produced in situ by the cells and enriched therewith can remain in the chamber despite the feeding of fresh medium. This culturing approach is gentler than the complete replacement of nutrient liquid. So this technology allows locally defined mixing to be achieved even for batchwise nutrient processes, i.e. for the first time also in non-recirculating systems. This makes it possible to combine the advantages of non-recirculating systems, such as meterability as well as definability and programmability, especially for pharmacological studies in minisystems, with the cell-biological advantages of largest possible biological milieu constancy. The vertical movements of the intermediate plates 37 can be caused by appropriate positioning and vertical movement of a cover plate structure 35 , which houses accordingly positioned magnets or coils. Operation is possible also with a fixed cover plate structure 35 , if in such case changing orientations of magnetic fields in said structure are induced by changing current flows in electric coils.
[0050] FIG. 17 represents a further embodiment of the invention, which comprises a culture bottle or bioreactor 60 with a cylindrical shape. The culture bottle is surrounded by a jacket 61 , which is made up of an elastic material, especially a plastic or rubber material, and has a cylindrical shape too. The culture bottle 60 with its jacket rests on the rollers 62 , 63 , which are rotated by a drive not shown.
[0051] The jacket 61 is provided with a hollow space 64 , which is limited by valves in the area of the end faces of the cylindrical jacket to interact with them and thus act as a pump through a change in volume. Advantageously, the change in volume can be achieved by permanent magnets with one permanent magnet 66 located in the jacket between the hollow space 64 and the culture bottle 60 and a second permanent magnet 65 beneath the jacket 61 . So the hollow space 64 is compressed when the permanent magnet 64 enters its lower position, because the magnets are arranged such that they attract one another in said position with the compression being assisted by the dead weight of the permanent magnet 66 . The hollow space is on the contrary compressed when the permanent magnet is in its upper position. So the pumping effect is eventually achieved in a simplest way by the drive for the running rollers 62 , 63 . They are connected with the hollow space 64 through hoses at the end faces of the culture bottle so that the fluid can circulate between the culture bottle and the hollow space in a batchwise flow initiated by the rotating movement of the apparatus.
[0052] As an alternative to the embodiment according to FIG. 17 , it is also possible to do without the permanent magnet 65 and replace the permanent magnet 64 by a weight. But another possibility is to replace the permanent magnet 66 by an electromagnet. | The invention relates to a device for pumping a fluid into a bioreactor. Polsatile pumping is made possible by valve arrangement so that growth of the cells in the bioreactor is increased. Pumping function can be achieved though several mechanisms. A piston can be displaced in a cylinder, especially by an electromagnet, wherein a permanent magnet or likewise an electromagnet can be arranged in the piston. The piston can also be displaced by compressed air. An elastic, hollow body can also be provided, wherein said hollow body can be deformed by mechanical electromagnetic forces so that pumping function is achieved by a change in volume. The pumping device can also be used as implant for assisting or replacing heart function. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
Non-applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Non-applicable
NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Non applicable
REFERENCE TO A SEQUENCE LISTING
Non-applicable
STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR
Italian Patent Application No. B02013A000345 filed Apr. 7, 2013.
DESCRIPTION OF THE INVENTION
The present invention relates to the technical field concerning the equipment for performing installation, repair and/or maintenance operations of pipelines, which carry fluids under pressure, for example gas, water, hydrocarbons and the like, without interrupting the service and avoiding the dispersion of polluting substances in the environment.
In particular, the apparatuses intended to operate on pipelines of medium dimensions are taken into consideration, for example those belonging to a distribution system, having the diameter of some inches, either below or above ground level, therefore excluding the domestic systems.
Such apparatuses are known as plugging machines and are installed in pairs, respectively upstream and downstream of the piece of pipeline to be acted upon, and joined with a temporary pipeline, so as to create a by-pass, into which the flow is deviated without being interrupted.
More in detail, the pipeline is perforated in two selected points, a connector and valve (called “flat valve” in jargon) are applied to each of the holes and then the respective plugging machines are fastened thereto; each of the latter includes a substantially bell-like, main body in which a plugging head is housed. The plugging head is lowered, by suitable means, made to pass through the flat valve and connector, so as to enter the underlying pipeline.
In the known solutions, the plugging head is lowered with its axis substantially orthogonal with respect to the pipeline and then rotated by 90°, so as to arrange it coaxial with the latter; afterwards, means are operated to move the two discs, provided at the head, close to each other. A sealing ring, made of rubber or the like, having for example a trapezoidal cross-section, is interposed between the two discs.
Due to the axial compression, the sealing ring expands radially, adhering strongly to the inner surface of the pipeline, thus making a seal. The passing fluid is forced to deviate within the main body of the plugging machine upstream, then to flow into the temporary pipeline and reach the plugging machine downstream, through which it is reintroduced into the pipeline via a reverse path.
From a constructive point of view, a plugging machine of known type presents the maximum complexity in the means which allow and control inclination of the plugging head. These means must comply, both from the strictly dimensional point of view and from the functional point of view, with the means that move the discs, between which the sealing ring is interposed, close and away from each other.
Independently from the mechanical solutions chosen for the above mentioned means and from their bigger or smaller functional validity, it is obviously understood that the strength and reliability characteristics, which are obtained with considerable dimensions in case of big plugging machines, cannot be found in plugging machines suitable for medium dimension pipelines (in proportion to the necessary dimension reduction, thus to the inner diameter of the pipeline).
In other words, some technical solutions, valid for certain dimensioning, become poor with reduced dimensions.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to propose a device associated to a plugging machine for sealing pipelines, particularly simple and essential, so as to obviate the principal drawbacks reported by the known solutions.
Another object of the invention is to obtain a device which is indicated, due to its constructive characteristics, with medium-small dimensions of the pipelines into which it is to be introduced, for example, with a diameter of a few inches, and consequently of the plugging machine.
A still further object of the invention is to realize a strong device, which is very rigid, so as not to be adversely affected by the pressure of the fluid and to assure a correct and stable position inside the pipeline, thus an optimal tightness.
A still further object of the invention is to propose a compact device, which is easy to handle due to its limited weight and dimensions, quick to be installed and equally quick to be removed, to limit the total cost of the operations that require its use.
These and other objects are wholly obtained by a device for sealing of pipelines associated with a plugging machine, with the latter being of the type designed for the execution of maintenance and/or repair operations in the pipelines, in which fluids under pressure are conveyed, and aimed at being fastened to a connector made integral and communicating with one of the pipelines, perpendicular to its axis, with the above mentioned device protruding downward from the plugging machine and inserted within the pipeline and including:
a rigid tube, supported by the body of the plugging machine and extended therebelow, so as to pass through the connector and insert into the pipeline with axis almost orthogonal thereto; a stationary disc, integral to the lower end of the rigid tube, arranged coaxial with the pipeline, provided with an axial through hole, with which the internal cavity of the same tube is set in communication and which has a face shaped like a truncated cone; a movable disc, arranged coaxial with and counter-facing the stationary disc, with a respective face having a truncated cone profile symmetrical to that of the face of the stationary disc, with the movable disc featuring an axial shank adapted to be inserted slidably in the axial hole of the stationary disc, so that the mutual distance between them can be adjusted; a sealing ring of elastomeric material, with a trapezoidal cross-section, interposed between the stationary and movable discs, the sealing ring having its outer diameter dimension slightly less than the internal diameter of the pipeline, in non-operating condition, in which the movable discs are not compressed axially, with the same stationary and movable discs mutually moved away, with the above mentioned ring expanding radially, in operating condition, in a manner as to adhere sealingly to the inner surface of the same pipeline, as a consequence of an axial compression exerted by mutual approaching of the discs; a control rod, slidably inserted in the tube, extended upwards to come out from the body of the plugging machine and downwards to abut against the axial shank of the movable disc; drive means, provided between the lower portion of the control rod and the shank of the movable disc, operated by axial translation of the rod to make the shank and the movable disc rigidly coupled therewith, carry out corresponding axial movements away from or close to the stationary disc, to determine respectively the non-operating and operating conditions of the sealing ring; operating means, associated to the upper portion of the control rod, provided to cause the axial movements of the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
The characteristics of the invention will become evident from the following description of a preferred embodiment of the device for sealing of pipelines under discussion, in accordance with the contents of the claims and with help of the enclosed figures, in which:
FIG. 1 is a schematic vertical cross-section of a plugging machine, provided with the sealing device under discussion associated to a pipeline;
FIG. 2 illustrates, in enlarged scale, the detail H of FIG. 1 , to point out the part of the device inserted in the pipeline, in non operating position;
FIG. 3 is a view similar to that of FIG. 2 , with the device in operative position;
FIG. 4 is a perspective view of a control rod of the device;
FIG. 5 is a cross-section view of a stationary disc of the device and a movable disc to be coupled with the stationary disc, moved away to be better pointed out;
FIG. 6 is a perspective view of the movable disc of the previous Figure.
DETAILED DESCRIPTION OF THE INVENTION
The device 1 is provided in connection with a plugging machine 100 of substantially known type shown schematically in FIG. 1 .
The plugging machine 100 is intended to be fastened to a connector 110 , made integral and communicating with a pipeline 200 that conveys a fluid under pressure.
The plugging machine 100 is designed to cooperate with a twin machine (not shown) associated with the pipeline 200 to create a by-pass that isolates a piece of the pipeline without interrupting the flow to allow maintenance and/or repair operations in the piece.
According to the invention, device 1 includes a rigid tube 2 supported by a body 101 of the plugging machine 100 and extending therebelow to pass through the connector 110 and a flat valve 120 of known type associated to the same connector 110 . In this way, the tube enters the pipeline 200 with an axis almost orthogonal to that of the latter.
In the non-limiting example shown in the figures, the tube 2 is inclined with respect to the condition of perpendicularity by about 4°.
The rigid tube 2 protrudes upwards from the body 101 passing through a collar 102 , which assures the tightness against the leaks of the fluid in a known way not shown in detail.
A stationary disc 3 is integral, for example as a single body, with a lower end 2 B of the rigid tube 2 . Due to the positioning of the plugging machine 100 on the pipeline 200 , the stationary disc 3 is arranged coaxial with the latter.
The stationary disc 3 is provided with an axial through hole 30 into which the internal cavity 20 of the tube 2 opens. The stationary disc 3 has a truncated cone-shaped face 31 opposite to the one facing the tube.
A first annular rim 310 is thus defined in the face 31 , the inner part of which slightly protrudes with respect to the outer part.
The stationary disc 3 mates with a movable disc 4 , arranged coaxial therewith, opposite thereto and featuring a face 41 with a truncated cone profile symmetrical to that of face 31 of the stationary disc 3 .
Consequently, a second annular rim 410 is defined in the face 41 of the movable disc 4 . An annular groove 5 having a trapezoidal cross-section is defined between the second annular rim 410 and the opposite first annular rim 310 . The annular groove 5 houses a sealing ring 50 of elastomeric material, having a complementary trapezoidal cross-section, in such a way that its sides remain in contact with the first and second annular rim 310 , 410 .
The movable disc 4 is provided also with an axial shank 40 adapted to run slidably within the axial hole 30 of the stationary disc 3 so that the mutual distance between the discs, and accordingly the width of the annular groove 5 , can be adjusted.
The external diameter of the sealing ring 50 is slightly smaller with respect to the inner diameter of the pipeline 200 , in non-operating condition R, in which no axial compression is exerted on the discs, that is when the movable disc 4 is moved away from the stationary disc 3 .
The ring 50 can expand radially in operating condition W in a manner as to adhere sealingly to the inner surface of the pipeline 200 , due to an axial compression caused by moving closer of the discs 3 , 4 .
A control rod 6 is provided to control the movements of the movable disc 4 close to or away from the stationary disc 3 from outside of the plugging machine 100 . The control rod 6 is introduced slidably into tube 2 , extended upwards to come out from the body 101 of the machine 100 and downwards to abut against the axial shank 40 of the movable disc 4 .
Drive means 7 are interposed between the lower portion 6 B of the control rod 6 and shank 40 and are, operated by axial translation of the rod 6 to make the shank 40 and the integral movable disc 4 carry out corresponding axial movements away from or closer to the stationary disc 3 and to determine respectively the non-operating condition “R” and operating condition “W” of the sealing ring 50 .
The drive means 7 include at least a slider 70 projecting transversely from the control rod 6 and provided with two faces 71 , 72 parallel to each other but sloping with respect to the longitudinal axis of the rod 6 .
The slider 70 is aimed at engaging in a complementary groove 44 made in the shank 40 so that the axial thrust exerted on the rod 6 , in one or the other direction, generates a component of a force parallel to the axis of discs 3 , 4 , by means of the contact surfaces 71 , 72 of the slider 70 and the corresponding surfaces of the groove 44 . Thus, according to the direction of this component, axial movements of the movable disc 4 away from or close to the stationary disc 3 are carried out.
In a preferred embodiment of the drive means 7 , two parallel flat surfaces 60 are made in the lower portion 6 B of the rod 6 , from which two respective symmetrical sliders 70 protrude.
The shank 40 of the movable disc 4 features a longitudinal slit 42 arranged on a median plane of the shank 40 , which is thus divided in two portions.
The facing faces of the slit 42 feature two of the above mentioned mirror-like grooves 44 , within which the lower portion 6 B of the rod 6 can be slidably introduced with its flat surfaces 60 , and the two sliders 70 can engage with the corresponding grooves 44 .
In order to obtain the movement of the movable disc 4 due to the raising and lowering of the rod 6 , it is necessary that the inclination angle of the sliders 70 and the grooves 44 coupled mating therewith is suitably determined with respect to the axis of the discs 3 , 4 . The value of this angle is comprised between 55° and 60°.
Operating means 8 , associated in the upper portion 6 A of the control rod 6 , can determine the axial translations of the rod 6 between two extreme positions corresponding to the non-operating condition “R” and operating condition “W” of the sealing ring 50 .
In another embodiment, the operating means 8 include a threading 80 made in the upper portion 6 A of the control rod 6 and aimed at meshing with a threaded hole 81 made in a screw ring 82 , the latter being rotatably supported by the rigid tube 2 and designed to be manually operated to rotate, in one direction or in the other, to raise or lower the control rod 6 .
Advantageously, the device 1 includes also anti-rotational means 9 , associated to the rigid tube 2 adapted to stabilize the position of the latter and of the integral stationary disc 3 in a manner that the axis of the stationary disc 3 , as well as the movable disc 4 , coincide on a horizontal plane with that of the pipeline 200 .
The anti-rotational means 9 are composed of, for example, a flange 90 locked at the upper end 2 A of the tube 2 from which a bar 91 protrudes radially and the bar is aimed at introducing in a fork 92 fastened to the body 101 of the machine 100 .
The figures illustrate a technical solution, according to which the bar 91 is hinged to the flange 90 to rotate upwards and release from the constraint of the fork 92 . This feature is useful in the installation steps and removal of the plugging machine 100 .
The present invention's simple and essential structure makes it suitable when the dimensions of the pipelines, in which it is to be introduced, are medium or medium-small, for example with a diameter of a few inches.
The device according to the invention is strong and very rigid due to the constructive solution of the tube which is made as a single body with the stationary disc.
In this way, a considerable resistance to the pressure exerted by the fluid is obtained and a correct and stable position inside the pipeline, and consequently an optimal tightness can be assured.
A special importance must be given to the conformation of the drive means which allow the movable disc to move close to and away from the stationary disc and consequently the sealing ring to be compressed and released. The solution of inclined sliders within likewise inclined grooves is very simple from a mechanical point of view, and, at the same time, it is effective in functional terms and extremely compact.
The combination of advantageous characteristics of the invention allows a compact and easy to handle device to be obtained due to its limited weight and dimensions, quick to be installed and equally quick to be removed so as to limit the total cost of the operation.
It is understood, however, that what has been described above is illustrative and not limiting, therefore, possible detail variations that could become necessary for technical and/or functional reasons, are from now considered within the protective scope as defined in the claims below. | This inventions relates to a plugging machine and a rigid tube provided with a stationary disc integral with the bottom of the tube and oriented almost orthogonal to the tube, with a movable disc paired with the stationary disc. A sealing ring of a resilient material is located between the discs and compressed when the movable disc is pressed against the stationary disc to adhere to an inner surface of the pipeline. The sealing ring is coaxial with respect to the pipeline. The movement of the movable disc is determined by raising or lowering a control rod within the tube by means of sloping sliders made in the lower portion of the rod which engage in respective grooves, likewise sloping, made in an axial shank associated with the movable disc and sliding inside an axial opening of the stationary disc. A component of a force is generated which is parallel to the axis of the discs. The axis is raised or lowered by rotation of a threaded ring engaging in a threading mate at the top of the rod. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates, in general to an equipment for loading an underlayer or second layer of cement material in moulds for making cement tiles, or the like, and in particular to new and useful apparatus which includes suction bell means having a porous diaphragm encircled by an edge, which is adapted to penetrate into a layer of material to be drawn into the bell means.
SUMMARY OF THE INVENTION
It is an object of the invention to reduce the time needed to carry out an operational cycle, in order to increase productivity. Another object is that of limiting the accelerations and decelerations of the equipment. Other objects and advantages will be evident to those skilled in the art.
According to the invention a number of bells are provided and carried by angularly and intermittently displaced means for subsequently moving each bell into at least a drawing up position and a laying down position of the material layer. Means are also provided to synchronically obtain the angular displacement and the vertical displacements of the bell equipment, and to establish in each bell, an atmospheric pressure or an underpressure.
In practice the equipment rotates intermittently around a column, along which it also slides axially. Pins for centering and checking the angular positions of the equipment are provided. A rotary shutter determines and establishes the atmospheric or under pressure in each bell.
A control system may be combined in the form of an arm, movable around the column and bearing a coupling pin engaging the shutter in any axial position of the equipment and also engaging the equipment in its raised position, to enable angular displacements of the shutter only, or of the shutter and the equipment, in an integral way. The equipment with three bells is displaceable into at least three angular positions around the column. Each of the bells cyclically reaches a drawing up position, a laying down position of the layer of carried material and at least one waiting position and, if required, a cleaning position.
Annular edges around the bells are adjustable with respect to the bell and the diaphragm to adjust the thickness of the layer to be drawn up by each bell.
Accordingly, another object of the present invention is to provide a device for loading a dosage layer of material at a laying-down position to form a tile comprising, material layer supply means adapted for providing a layer of material in a drawing-up position, bell means having an air-permeable diaphragm and surrounding edge defining a dosage space for receiving the dosage layer of material, drive means connected to the bell means for intermittently moving the bell means into the drawing-up position to receive a dosage layer of material in the dosage space and then into the laying-down position to release the dosage layer of material, and suction means connected to the bell means for establishing an underpressure therein when the bell means is in the drawing-up position for holding the dosage layer in the dosage space and for establishing atmospheric pressure in the bell means when the bell means is at the laying-down position to release the dosage layer of material.
A further object of the invention is to provide a device for loading a dosage layer of material which is simple in design, rugged in construction and economical to manufacture.
For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawings.
FIGS. 1 and 2 are partial plan and vertical section views respectively, with FIG. 2 taken alone broken line II--II of FIG. 1, of a moulding equipment with a metering device according to the invention, in a first array, that is in a first phase or position operation;
FIG. 3 is similar to FIG. 2, but shows a second phase of operation;
FIGS. 4 and 5 are similar to FIGS. 1 and 2 respectively, but show an array corresponding to a third phase of operation;
FIG. 6 is similar to FIGS. 2, 3 and 5 and shows an array corresponding to a fourth phase of operation;
FIGS. 7, 8 and 9 show details of FIG. 2, with FIGS. 8 and 9 taken from the lines VIII--VIII and IX--IX of FIG. 7 respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the annexed drawing, and FIG. 1 particularly 1 denotes a rotating table typical of a rotary press having several moulds 3A, 3B, 3C thereon which denote the mold frames in their positions. The position of the frame 3B is that of loading of the so-called second layer or underlayer of the cement tile to be formed. 13B denotes the bottom of the frame in position 3B (FIG. 2). The table 1 rotates stepwise in the direction of arrow f1, to move each mould into the various positions. Mould in the position 3A has received the material of the surface layer S1 and then is moved to the position 3B-13B to receive the material of the second layer or underlayer denoted by S2, in order to be moved afterwards to the position 3C and the subsequent ones for the pressing and the drawing steps.
The apparatus to be described effects the automatic loading of the material of the second layer S2 and the dosage of the same, within a relatively short time and, in any case, a time which will not delay the production rhythm of the tile plant, and with the maximum uniformity of distribution of the material and compactedness of the same.
A tank is provided for the feeding of the second layer material, with an arrangement oriented according to a certain inclination with respect to the radial direction defining the position 3B of the mould which must receive the underlayer or second layer S2. This tank has a hopper 15 overlaying a continuous flexible belt conveyor 17, which is moved by rollers 19, 21. This conveyor is operated to be intermittently rotated by a power unit 23 which can operate the plant with intermittent movement. The flexible belt conveyor 17 is porous, that is air-permeable, and its upper horizontal run may slide upon a support 25, which is also porous, that is air-permeable. On the lower arm or run of the belt 17, a cleaning brush 27 may operate. Below the conveyor belt 17 a conduit or a collection hopper 29 is provided for the excess material which must be carried away or lead back to the hopper 15. At least the conduit or the hopper 29 may be vibrated. From the hopper 15 the material M which is to form the underlayer is fed in the form of a layer SO on the conveyor belt 17 and the thickness of this layer SO may be adjusted by displacing a scraper or blade 31 with an adjustment device 33, which allows a vertical displacement of this scraper and, advantageously, also its vibration, to make the formation of the layer SO even.
In a substantially radial alignment with the mould in position 3B and outside the table 1, a column 35 is placed and borne from a base 37, whose upper part may also be supported (FIG. 2). An arm 39 is integrally connected to an upper part of colum 35. One of the two elements of a cylinder-piston system 41 is fixed, to arm 39 and the other element is pivotally connected to an arm 43 idly borne by the column 35. With the arm 43, a coupling pin 45 is integrally connected which is vertical and therefore parallel to the column 35. This coupling pin 45 is angularly but not axially movable with respect to the column 35. Pin 45 with actuator 41 and arm 39 form rotary drive means.
A collector 47 is engaged on the column, which is axially displaceable, but angularly stable. The collector 47 is connected through a bellows 49 with a conduit 51 leading to the suction side of a suction pump 53.
An element 55 is mounted on the column 35, to slide and to rotate, which forms a turret provided with three bells or bell means 57 angularly equidistant from one another with respect to the axis of the column 35. Each bell can subsequently reach three positions, which are shown at 57A, 57B and 57C. The bell in position 57A (laying-down position) is set above the frame 3 of the mould in position 3B; the bell in position 57B is set above the active arm of the conveyor belt 17 and in correspondence of the support 25 and the bell in position 57C is in a waiting position. The equipment or turret 55, bearing the bells 57, is axially connected to the collector 47 with suitable resilient connection means 59 or the like, so that between the collector 47 and an upper plate 55A of the equipment 55 at a sealing pressure, a movable shutter 61 is interposed. From the plate 55A connections 63 extend between the interior of bells 57 and the surface of the plate 55A connected to the shutter 61. This shutter 61 has a bore 61A, which may be displaced by 120°, as it can be appreciated comparing FIGS. 1, 4 and 7 and as it appears from FIGS. 7 and 8. Considering these figures it is clear that the shutter 61 and therefore the bore 61A may be displaced between two radial fixed alignments shown with X and Y; the alignment X corresponding to that between the column 35 and the angular displacement axis of platform 1, while the alignment Y corresponds to that of the symmetry vertical plane of the assembly 15, 17. The shutter 61 has a radial fork appendix 61B, within which the connecting pin 45 is engaged, and with respect to which pin the fork appendix 61B can move in parallel to the axis of the pin 45. Also the plate 55A of the equipment 55 has a fork or bore-like appendix 55B, which may engage the pin 45 in a lowered position of the equipment 55. The collector 47 has an opening 47A (see in particular FIGS. 7 and 9) which extends at least between the above mentioned angular positions X and Y. The shutter 61 has two recesses 61C on the lower connection surface with plate 55A. These recesses 61C are moved so as to enable the presence of one of them alternatively in the positions 57A and 57B, with the displacement of member 61 for an angular magnitude substantially corresponding to the angle between the two radial alignments X and Y.
The cylinder-piston system 41 can move the pin 45 by an angular length with respect to the column 35 equal to the angle between the two alignments X and Y.
The equipment 55 has in its lower part a flange 55C, which is engaged in an angularly movable manner by a moulded end 65A of the stem of a piston 65 of a cylinder-piston system or vertical drive means, whose cylinder 67 is integral with the base 37. The system 65, 67 serves to raise and lower the equipment 55 and therefore the bells 57, while allowing their rotation. The flange 55C has a bore 55E capable to cooperate with a fixed centering pin 69, when the equipment 55 is lowered.
Each of the bells 57 has a perimetrical edge 71, which is carried by the structure of the respective bell through replaceable thicknesses or spacers 73 for the arrangement of the position of the edge 71 and therefore for the dosage or thickness of the underlayer S2. The adjustment of each of the edges 71 is effected with respect to a porous diaphragm, that is to a porous wall 75 in the lower part of each bell 57. The edge 71 is projected more or less downwards with respect to the wall 75 with its own beveled edge adapted to penetrate into the material of the layer SO until it is in contact with the belt conveyor 17, while the porous wall 75 must touch the layer SO. This is obtained through suitable relative adjustments between the press and the loader assembly and/or between the press and the equipment 55-57 and/or between the latter and the assembly of the conveyor 17.
The operation of the assembly is as follows.
In a first initial phase of operation, the various elements are in the position shown in FIGS. 1 and 2. In this position, the bell in position 57B is opened towards the atmosphere due to the presence of the recess 61C in correspondence of the connection 63 of the bell 57B. The bell in position 57A is exposed to underpressure through its own connection, the bore 61A and the collector 47A, 47. The bells with the equipment 55 are raised above the layer SO and the layer S1 and the frame 3B. The bell in position 57A holds the quantity of underlayer S2 between the edge 71 and the wall 75, the holding of the material being due to the depression of pressure in the bell and therefore to the suction of air through the material of the layer S2. The equipment 55 being raised, the pin 45 engages both appendixes 61B, 55B. In this array, the table 1 has been moved and a mould has arrived in the position 3B which is to receive an underlayer S2.
In the subsequent phase (FIG. 3) the cylinder-piston system 65, 67 lowers the equipment 55 centering it with the pin 69, so as to ensure the exact penetration of the edge 71 of the bell into position 57A inside the frame in position 3B. The bell 57A is lowered then in the frame while still holding the layer S2, and the bell in position 57B penetrates with its own edge 71 in the layer SO, the bell 57B still standing at atmospheric pressure. The penetration of the edge 71 into the layer SO must be such as to contact the conveyor 17, and adjustment of the edge 71 itself is obtained through the selection of the thicknesses 73. The pin 45 maintains the appendix 61B of the shutter engaged, but loses its hold on the appendix 55B.
From this array of FIG. 3 in a third phase the array of FIGS. 4 and 5 is reached. In this array the bells maintain the position already reached in FIG. 3, but the distributor or shutter 61 was moved from the position of FIG. 1 to the position of FIG. 4 by virtue of the cylinder-piston system 41. In this way the communication between the bells in position 57B and the conduit 51 is obtained, thereby the material defined by the edge 71 of said bell sticks against the porous wall 75 by the effect of the air stream flowing across the conveyor belt 17 and the permeable support 25. Conversely, the bell in position 57A reaches atmospheric pressure because of the passage of air towards the interior of the bell from the recess 61C. If a layer of material S2 was kept, by suction, against the wall 75 by means of the suction effected by the bell 57A, this material of layer S2 now falls, or, more specifically is laid down upon the layer S1 of the mould in position 3B, within whose frame the edge 71 of the bell stay in position 57A.
In a forth phase (see FIG. 6) the cylinder-piston system 65, 67 raises the equipment 55, 55A and then the bells 57 to reach the position shown in FIG. 6. With respect to the condition shown in FIG. 5, there is a another layer S2 raised with the porous wall 75 of the bell in position 57B and the raising of the bell 57A without the layer S2, which remains laid down upon the layer S1 of the mould in position 3B.
In the above conditions an angular motion of the table 1 occurs of an angular length between two subsequent moulds, so that a mould that contains only the layer S1 reaches position 3B, while the mould with the layers S1 and S2 is moved to a subsequent pressing or vibration position. The equipment 55, 55A simultaneously shifts by 120° according to arrow f6 and by virtue of the control of the cylinder-piston system 41 which carries said equipment integral with the bells and the distributor 61, since the pin 45 for raising the equipment 55, 55A has engaged again, besides the appendix 61B, also the appendex 55B. As a consequence, the bell which was before in the position 57A shifts to the waiting or cleaning position 57C, since the same bell is without the material S2. The bell previously positioned at 57B moves with the new layer S2 to the position 57A above the new mould which reaches the position 3B, 13B. The bell previously located in the waiting position 57C reaches the position 57B. Thus, the starting conditions of a new cycle are reached again as shown in FIGS. 1 and 2.
Meanwhile the conveyor belt 17 was advanced so as to have the continuous layer SO again under the bell in the position 57B and to mask the empty region V, shown in FIG. 6, and due to the drawing of the layer S2 through the bell 57B, raised in the array of FIG. 6. The excess material which passed below the position 57B of the bells (to ensure a uniform layer SO for a new drawing step) falls into the collection hopper 29 and can be raised again within the supply hopper 15. Practically, in this fifth phase, the same conditions of FIGS. 1 and 2 are actually reached again, except the shift by 120° of the equipment 55, 55A of the bells 57 and the angular shift of the mould table equal to the distance between subsequent moulds.
From this position a new cycle to lay down the just raised layer S2 and to draw a new layer S2 is resumed.
It is evident that the described equipment permits reduced times and therefore the increase of the working rhythm with an acceleration of the production, while, however, excessive accelerations and speeds of the cyclic motion elements is not required.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A device for loading a dosage layer of material, preferably concrete, at a laying-down position for manufacturing tiles and the like comprising, a conveyor for supplying a continuous layer of the material, a bell having a diaphragm and edges surrounding the diaphragm defining a dosage space for receiving a dosage layer of the material and a driving unit for driving the bell to move it into engagement with the continuous layer on the conveyor to receive a dosage layer of material in the dosage space. A suction pump is connected to the interior of the bell for establishing an underpressure therein so that the dosage layer of material is held by suction in the dosage space. A plurality of the bells may be provided on a single turret so that one dosage layer of material is being drawn up while another dosage layer of material is being laid down at another location. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application, Serial No. 103 26 175.3, filed Jun. 10, 2003, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates, in general, to a tablet press, and more particularly to a tablet press of a type having a rotary turret for producing pellets.
[0003] FIG. 1 shows an exemplary configuration of a conventional tablet press. The conventional tablet press is hereby driven by a motor 2 which drives a cylindrical rotary turret 1 through a gear 4 and a toothed belt 5 . The material is compressed in the rotary turret 1 . The rotary turret 1 includes vertically extending bores, which are not shown in FIG. 1 for sake of clarity. The rotary turret 1 is filled via a filling unit 6 with a filling medium to be compressed to a tablet or pellet. Pressure is applied to the filling medium by way of two pressure rams via an upper idler pressure roller 7 and an additional lower idler pressure roller 8 , thereby compressing the filling medium into a tablet or pellet.
[0004] FIG. 2 shows schematically the basic operating principle of the press. The rotary turret 1 is first filled by a filling unit 6 . The pressing forces generated by the upper pressure roller 7 and the lower pressure roller 8 are then transferred to the filling medium 14 via an upper pressure ram 11 and a lower pressure ram 10 , which for sake of clarity are only labeled once in FIG. 2 , thereby compressing the filling medium 14 into the shape of a tablet. The pressed tablet is subsequently ejected.
[0005] The drive turns the rotary turret 1 so that the rotary turret 1 passes between the upper pressure roller 7 and the lower pressure roller 8 with a substantial force, thereby generating the pressing force onto the upper pressure ram 11 and the lower pressure ram 10 .
[0006] Since the pressure rollers 7 , 8 apply a significant force to the filling medium and the pressing force is generated at a high rate when the pressure rams pass under the pressure rollers, significant torque peaks and vibration excitations are applied to the entire mechanical system and/or to the drive train of the tablet press which includes the motor 2 , the gear 4 , the toothed belt 5 and the driveshaft 9 . The generated mechanical vibrations place a significant load on the components of the drive train. The conventional elastic drive train can itself vibrate and thereby enhance the vibration spectrum which worsens the dynamic characteristics of the compression machine and the drive train. The large distance between rotary turret 1 and the actual motor 2 makes it difficult to produce a mechanically stiff system. Expensive mechanically damping means and complex control mechanisms may have to be employed to dampen the vibrations. Even with such complex damping arrangements, the vibration load can only be reduced so far, so that the mechanical components of the pellet press continue to be exposed to a high mechanical load.
[0007] It would therefore be desirable and advantageous to provide an improved tablet press which obviates prior art shortcomings and is able to specifically place significantly less stress on the mechanical components and the drive train of the tablet press due to vibrations.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a tablet press includes a rotary turret for compressing a material into the shape of a pellet, and a direct drive for operating the rotary turret.
[0009] The present invention resolves prior art problems by replacing a conventional drive train formed of a motor, gear, toothed belt and driveshaft with a direct drive, i.e., a drive that does not include a gear and/or a toothed belt. By employing a direct drive for driving the rotary turret, drive components such as toothed belts and gears can be entirely eliminated. Because the drive now drives the driveshaft of the rotary turret directly, the additional vibrations typically observed when drive components, such as the motor or the gear, are relatively far spaced are eliminated. Also eliminated are effects due to the excitation of vibrations by the drive that or amplification of vibrations through resonances, because a direct drive can be closely coupled on the stator side and the rotor side. Elimination of the vibrating drive train significantly improves the dynamic properties and the control characteristics of the press. The compact design of the drive train enables a more compact force transmission in the machine base, which reduces wear of the drive train over the life of the press, while also reducing the expenses associated with maintenance and service of the press. Moreover, the lower intensity of the mechanical vibrations also contributes to a significant reduction in the noise.
[0010] A particularly rigid mechanical construction can be realized by connecting the rotary turret with the direct drive via a driveshaft.
[0011] Advantageously, the driveshaft and the motor of the direct drive can be implemented as a single component. This reduces the number of components of the drive.
[0012] According to another feature of the present invention, the driveshaft and the rotary turret can be connected by a releasable coupling. In this way, the rotary turret can be easily attached to and removed from the driveshaft.
[0013] According to another feature of the present invention, a vibration-damping coupling can be placed between the driveshaft and the rotary turret. Such vibration-damping coupling between driveshaft and rotary turret not only reduces the severity of the vibrations, but can also dampen other residual vibrations.
[0014] According to another feature of the present invention, a vibration-damping coupling can be provided between the stator of the direct drive and the machine bed. Such vibration-damping coupling between the stator and the direct drive of the machine bed represents an additional vibration-damping measure.
[0015] Advantageously, the direct drive can be implemented as a torque motor, which is commonly used as a direct drive.
BRIEF DESCRIPTION OF THE DRAWING
[0016] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0017] FIG. 1 is a schematic illustration of a conventional tablet press;
[0018] FIG. 2 is a detailed diagram of a pressing operation; and
[0019] FIG. 3 is a schematic illustration of a tablet press according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.
[0021] In the tablet press of the present invention, a conventional drive train formed of a motor, gear, toothed belt and driveshaft is replaced with a direct drive, i.e., a drive that does not include a gear and/or a toothed belt.
[0022] Turning now to the drawing, and in particular to FIG. 3 , there is shown an exemplary schematic embodiment of a tablet press according to the invention. The rotary turret 1 is filled by a filling unit 6 with a filling medium to be compressed. The pressure required for the compression is applied via the upper idler pressure roller 7 and the lower idler pressure roller 8 through pressure rams which are not shown for sake of clarity. In all other aspects, the mechanical compression process and the operation of the press correspond to that of the conventional presses depicted in FIG. 1 and FIG. 2 , respectively.
[0023] Unlike the conventional tablet press depicted in FIG. 1 , the tablet press according to the invention employs an entirely novel drive concept for tablet press. The rotary turret 1 , which rotates between the two pressure rollers 7 and 8 , is no longer driven, as in FIG. 1 , indirectly via a gear and a toothed belt 5 , but is rather driven by a direct drive. This eliminates the need for drive components, such as a toothed belt and a gear. The overall force transmission via the driveshaft 9 and the stator 17 of the direct drive to the machine bed 18 is also significantly more compact and stiffer.
[0024] The rotary turret 1 is herein connected via a coupling 12 (indicated by two dotted lines) with the driveshaft 9 , whereby only one of the dotted lines has the reference numeral 12 . The coupling 12 between the rotary turret 1 and the driveshaft 9 can also be releasable, by which the rotary turret 1 can be easily attached to and removed from the driveshaft 9 . Advantageously, the driveshaft 9 and the rotor of the direct drive in the depicted embodiment form a single component, so that the driveshaft 9 in this embodiment is an integral component of the rotor of the direct drive. Accordingly, only a very small number of mechanical components are required to drive the rotary turret 1 . The driveshaft 9 and/or the rotor of the direct drive are rotatably supported in the stator 17 of the direct drive. The direct drive is hence composed of the stator 17 and a rotor, which in the depicted embodiments is also implemented as the driveshaft 9 . It will be understood that the driveshaft 9 and the rotor of the direct drive can also be fabricated as two separate components.
[0025] The stator 17 of the direct drive is connected with the machine bed 18 via a coupling 13 . The coupling 13 is indicated in FIG. 3 by two dotted lines, whereby only one of the dotted line has the reference numeral 13 .
[0026] The coupling 12 and/or the coupling 13 can also be made, for example, of a screw connection that is supported by a vibration-damping support.
[0027] The rotary turret 1 is directly the driven by the rotor of the direct drive implemented as the driveshaft 9 . The compact and rigid construction of the drive of the rotary turret significantly reduces and often completely eliminates mechanical vibrations.
[0028] In the depicted embodiment, the direct drive is implemented as a torque motor, because torque motors tend to generate a high torque at a relatively low rotation speed. However, other types of direct-driven motors or direct drives can also be used.
[0029] It should be mentioned that the term “tablet” and “pellet” are used interchangeably. Accordingly, the aforedescribed press can produce tablets as well as pellets, which are used, for example, for producing food, feedstock, combustion products and the like. It should also be mentioned that the cylindrical rotary turret is only one possible embodiment of such rotary turret and that other turret shapes of are feasible.
[0030] Moreover, the pressure to be applied to the filling medium can not only be produced by two pressing rollers and pressing rams, but by other means known in the art, such as hydraulic actuators. However, those embodiments that lack a direct drive still have problems with strong mechanical vibrations.
[0031] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
[0032] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: | A tablet press with a rotary turret that is driven by a direct drive is described. The rotary turret can be driven by a simple, inexpensive drive having low vibrations, which reduces the stress on the mechanical components and the drive train of the press. | 1 |
CROSS REFERENCES RELATED TO THE APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 12/547,393 filed Aug. 25, 2009, now U.S. Pat. No. ______, which is a continuation of U.S. patent application Ser. No. 11/948,889 filed Nov. 30, 2007, now U.S. Pat. No. 7,587,100, which is a continuation of U.S. patent application Ser. No. 11/273,055 filed Nov. 14, 2005, now U.S. Pat. No. 7,391,929, which is a continuation in part of U.S. patent application Ser. No. 09/782,235 filed Feb. 12, 2001, now U.S. Pat. No. 7,027,663, which claims the benefit of U.S. Provisional Application No. 60/181,778 filed Feb. 11, 2000.
FIELD OF THE INVENTION
[0002] This invention relates generally to graphical editing technologies, and more particularly, to controlling applications of effects by using masking tools.
BACKGROUND OF THE INVENTION
[0003] With the increasing popularity of computing and the use of the Internet in many fields, the ability to control computers and similar devices in a simple, convenient manner has become extremely important. However, existing interfaces to computers and similar devices can be cumbersome and complicated.
[0004] In particular, many users of graphical editing programs would benefit from an improved interface used to control the application of various special effects onto an image. For example, graphical editing programs would benefit from improved control of the application of the effects with respect to the intensity and the area of the image that is being subjected to modification by application of the effect.
[0005] Some software applications implement mask tools that are similar to applying a cut out or stencil to protecting area of the underlying image. They also implement control that applies effects only to a localized area, similar to a street paint tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The embodiments of the invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate these embodiments.
[0007] FIG. 1A illustrates an exemplary system implemented with an embodiment of the invention.
[0008] FIG. 1B illustrates a network overview of the present invention.
[0009] FIG. 1C illustrates a basic processor of the present invention.
[0010] FIG. 2A illustrates an embodiment of a masking tool operating in accordance with the invention.
[0011] FIG. 2B illustrates another embodiment of a masking tool operating in accordance with the invention.
[0012] FIG. 2C illustrates another embodiment of a masking tool operating in accordance with the invention.
[0013] FIG. 3 illustrates an exemplary embodiment of a selection process for the masking tool of FIGS. 2A-2C .
[0014] FIG. 4 illustrates an exemplary embodiment of a customization process for the masking tool of FIGS. 2A-2C .
[0015] FIG. 5 illustrates a flow diagram of one embodiment.
DETAILED DESCRIPTION
[0016] In the following detailed description of the embodiments of the invention, references are made to the accompanying drawings in which like references indicate similar elements, in which, is shown by way of illustration of specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.
A. General System Architecture
[0018] Beginning with an overview of the operation of the invention, FIG. 1A illustrates a system 100 which can control the effects of image manipulation according to one embodiment of the present invention. System 100 includes server 101 and one or more clients 103 . Stored in memory resident within server 101 , a typical software application 104 is an image-editing package adapted to manipulate images provided by client 103 . The operations of software application 104 may be controlled by server 101 or through control information from client 103 . Within the software application 104 , an effects block 110 and a masking tool block 112 reside. These “blocks” denote a collection of one or more instructions, including but not limited to a routine, function, or any other process. The effects block 110 applies a specific effect to the image and the masking tool block 112 selectively limits the area of the image which is modified by the effects block 110 .
[0019] As shown in FIG. 1B , client 103 may establish communications with server 101 through a wide area network. For instance, client 103 may communicate directly with an Internet Service Provider (ISP) that communicates with server 101 .
[0020] A client 103 represents any device that may enable user's online access to information. Illustrative examples of a “client” may include, but are not limited or restricted to a digital camera, a stand-alone device to view images inclusive of a kiosk, a hand-held image viewing device (e.g., portable computer, personal digital assistant, iPOD® or other music/video/image viewing device, etc.), a camera cellular phone, and the like. In this embodiment, client 103 may provide a user interface to communicate information to the user. It should be noted that although FIG. 1A illustrates only two modules performing the above functionality, more or less modules may be used to perform this functionality.
[0021] One exemplary embodiment of client 103 is a digital camera 140 that is illustrated in FIG. 1C . For this embodiment, digital camera 140 includes a processor 150 , a memory 155 and an input/output device 160 coupled to a bus 165 . Input/output device 160 includes an interface to establish a wired or wireless communication path with server 101 . Memory 155 is configured to store images that are captured by digital camera 140 and processed by processor 150 .
[0022] Memory 155 encompasses various types of computer readable media, including any type of storage device that is accessible by processor 150 . One of the skilled the art will immediately recognize that the term “computer readable media” encompasses any suitable storage medium such as a programmable electronic circuit, any type of semiconductor memory device such as a volatile memory (e.g., random access memory, etc.) or non-volatile memory (e.g., read-only memory, flash memory, etc.), a hard drive disk, or any portable storage such as a floppy diskette, an optical disk (e.g., compact disk or digital versatile disc “DVD”), memory stick, a digital tape or the like.
[0023] Of course, it is appreciated that digital camera 140 may be controlled by operating system software including instructions executed by processor and stored in internal memory. Also, software application 104 may be implemented within memory 155 or another memory component that is integrated within processor 150 or external to processor 150 in lieu of or in addition to such storage within server 101 . Thus, the digital camera 140 may perform masking operations and applying effects to the image directly.
[0024] As a first illustrative example, software application 104 may be loaded into server 101 to perform the masking and application of effects on an image as described below. These masking operations are controlled by the digital camera 140 . According to a second illustrative example, the software application 104 may be loaded within digital camera 140 to perform the masking and application of effects on an image, but the masking tool is fetched by digital camera 140 from memory implemented within server 101 . According to a third illustrative embodiment, a high-resolution image targeted for manipulation is loaded on server 101 while a low-resolution image loaded in digital camera 140 . In response to selected operations on the low-resolution image, corresponding operations are performed on the high-resolution image.
B. Embodiments of the Masking Tool
[0026] FIG. 2A illustrates a first embodiment of a masking tool as described in block 112 of FIG. 1A . Display 200 represents a sample screen while utilizing the software application 104 ( FIG. 1A ). A masking tool 210 is shown on the display 200 , where masking tool 210 features one or more graphical representations. These graphical representations may be have a predetermined shape and size and/or may be set by the user to produce a customizable graphical representation. The predetermined forms of masking tool 210 may be preloaded into the digital camera during manufacturer or downloaded from a source over a network connection. The customized graphical representations of masking tool 210 may be stored within digital camera upon completion by the user, and may be transmitted to the server 101 for storage.
[0027] For instance, as shown in FIG. 2A , the embodiment of masking tool 210 is translucent and is defined by the clear outline. The masking tool 210 allows a selective application effects from the effects block 110 ( FIG. 1A ) by moving the masking tool 210 with respect to a static image as shown on the display 200 . The portion of the static image as shown on the display 200 which is within the masking tool 210 is not modified by the application of the effects. This static image may be still image or an image from a video stream.
[0028] Furthermore, the masking tool 210 is capable of being dynamically moved with respect to the static image during the application of the effects. This allows the user to selectively apply the effect by interactively moving the mask tool simultaneously while applying the effect.
[0029] Another embodiment includes a masking tool that is able to interact directly with a localized image editing operation. For example, the masking tool may become entirely transparent in the immediate area where a user is currently applying an image effect. This allows the user to see the entire area that is mask without a mask or line obstructing the immediate work area.
[0030] FIG. 2B illustrates a second embodiment of masking tool 215 represented on display 200 . Masking tool 215 shows the portion within masking tool 215 to have a cross-hatched shading. Any type of shading can be utilized to illustrate the portion within the masking tool.
[0031] FIG. 2C illustrates a third embodiment of the masking tool represented on display 200 . According to this embodiment, the shape of the masking tool can be easily created and modified. For example, within the display 200 there are a first masking tool 220 , a second masking tool 230 and a third masking tool 240 . Each of the first, second and third masking tools ( 220 , 230 , and 240 ) have differing sizes and may function independently or may be combined to form a single masking tool. Naturally, this specific example utilizes three portions to form independent or combined masking tools and any number of portions may be utilized to accomplish the same.
[0032] Like masking tools that take different sizes, masking tools may also take any multitude of shapes. The masking tools may simulate the use of a fixed edge such as a French Curve. The shape of the mask tool is infinitely changeable. Furthermore, the user may mask as much area of the image as desired and perform a global image effect on the entire image while protecting portions of the image from the image effects with the masking tools.
[0033] FIG. 3 illustrates an exemplary embodiment of a screen display 300 featuring icons 310 representing various shapes for the masking tool. According to this embodiment, upon execution, a masking tool 320 is selected from icons 310 corresponding to a plurality of masking tool with graphical representations, namely different fixed shapes and sizes. Such selection may be accomplished by cycling through a series of masking tool icons 310 displayed on screen display 320 of a digital camera 330 using at least one control button 340 of digital camera 330 . Alternatively, although not shown, such selection may be accomplished through a menu displayed on screen display 300 of digital camera 330 , where the menu illustrates images or lists textual descriptions of the plurality of masking tool types. The selection of the menu entry is also controlled by control button(s) 340 .
[0034] FIG. 4 illustrates an exemplary embodiment of customization of the masking tool is shown. Display 200 of client 103 features an image 400 . Using a stylus 410 , for example, a pattern 420 is traced over image 400 illustrated by display 200 . Upon completion of an enclosed pattern, a determination is made whether the area within the enclosed pattern 420 is selected to be the masking tool, illustrated in a transparent form, or whether the area outside the enclosed pattern 420 constitutes the masking tool. For instance, upon touching stylus 410 within a first area 430 , namely the area within enclosed pattern 420 is considered to be the masking tool. As a result, when applied, an effect will be applied to the portion of image 400 outside first area 430 while no effect is applied inside first area 430 outlined by the masking tool. The transparent nature of the masking tool allows the user to see the lack of effects applied to the masked area. However, upon touching the stylus within a second area 440 , namely the area outside enclosed pattern 420 , any effect will be applied to the portion of image 400 inside first area 430 because the masking tool now covers second area 440 .
C. Operations of the Masking Tool
[0036] FIG. 5 illustrates a flow diagram. At block 500 , the application software 104 ( FIG. 1A ) is initiated. The user may build, create, and/or modify the shape and size of the masking tool in Block 510 . The user may position the masking tool relative to the static image (Block 510 ). The user may position the masking tool relative to the static image (Block 520 ). The user may apply the image effect selectively to the image that is not masked by the masking tool (Block 530 ). The user may dynamically reposition the masking tool while simultaneously applying the image effect (Block 540 ).
[0037] Although specific embodiments have been illustrated and described herein, will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for specific embodiments shown. This application is intended to cover any of the adaptations of variations of the present invention.
[0038] The terminology used in this application with respect to network architecture is meant to include all client/server environments. Therefore it is manifestly intended that this invention be limited only by the following claims and equivalents thereof. | A system for controlling effects performed on an image includes a digital camera having a display that displays the image. Masking tools position graphical representations on the display to define a portion of the image that is altered when the effects are subsequently applied to the image. The several masking tools may be combined to form a single masking tool. | 6 |
FIELD OF THE INVENTION
This invention relates to processes for coating sewing thread, and in particular to processes for coating sewing thread using solventless systems.
BACKGROUND OF THE INVENTION
Sewing thread is typically constructed from multiple continuous filament multifilament plies which are individually twisted in one direction and then combined by twisting in the opposite direction to produce a multiple ply final thread. In general, this causes the separate plies to act as a single unitary ply during the sewing process.
In many highly demanding industrial environments, it can be necessary to further treat sewing thread prior to its use. Such treatments can improve the integrity and retention of individual filaments within the sewing thread under conditions of high abrasion, improve the adhesion of the plies or individual filaments to each other in monocord or multicord constructions, and improve durability of the thread in its final end use. In these instances, the thread is coated with a bonding agent in the form of a lacquer or other plastic material which essentially forms a solid yet flexible film or sheath surrounding the thread. This allows the thread to retain substantial flexibility because the individual filaments of the thread retain the ability to have some movement relative to each other.
If the bonding agent fully penetrates the cross-section of the thread, however, the individual filaments are bound to each other and a stiff thread results. Such a stiff thread performs similar to a monofilament thread and can be unacceptable for many end use applications.
Conventionally, sewing thread is coated by passing the thread through a suitable resin in a solvent and then through a heating oven which evaporates the solvent and leaves the film. This operation, however, can be slow and releases organic solvent materials into the atmosphere. In addition, the film or sheath tends to flake off the sewing thread when used in demanding applications. The flaking is highly undesirable because it produces a visible dandruff-like deposit on the product. Further, energy required to remove the solvent can increase production costs.
Solventless systems can avoid many problems associated with solvent based coatings. In an exemplary solventless system, sewing thread is coated with a prepolymer material (such as a monomer plus a catalyst) which is capable of reacting to form a film when exposed to ultraviolet (UV) radiation. However, radiation curable systems also tend to flake off the sewing thread when the sewing thread is used in demanding applications. Other problems which can be associated with the use of many solventless systems include incomplete cure, tackiness, low adhesion and low production speeds.
SUMMARY OF THE INVENTION
The present invention provides processes for coating sewing thread using solventless systems. The solventless systems are generally more environmentally acceptable than conventional solvent based systems. In addition, the solventless systems can be applied to the thread and then cured in an in-line process at a greatly increased rate as compared to solvent based processes, which can reduce production costs. Solvent or water does not have to be removed from the solventless system after coating, thus reducing energy costs. In addition, sewing thread can be coated using smaller sized equipment, thus reduction production space.
In contrast to prior solventless systems, however, the coated sewing thread exhibits improved resistance to flaking and powdering. In addition, the coated sewing threads of the invention can have excellent adhesion properties which can protect the thread surface during demanding high speed industrial applications.
In the invention, a radiation curable material or resin system is applied in-line to a continuous threadline. When the thus coated thread is exposed to radiation, the radiation initiates polymerization or cure of the resin. In contrast to prior solventless systems, however, the radiation initiates a reaction that is self sustaining following initiation, as explained below.
Preferably, the radiation curable system is a cationic initiated system in which the radiation initiates a self sustaining crosslinking reaction following initiation, in contrast to many radiation cured polymers which are based upon a free radical mechanism. In the latter type mechanism, it is currently believed that the reaction only proceeds in the presence of UV radiation. However, in the case of a sewing thread, it is believed that at least a portion of the resin applied to the thread is shielded from the UV radiation by the individual filaments in the thread. Thus, for free radical initiated UV resins, the shielded portion of the resin is never fully reacted and hardened.
In contrast, for cationic initiated resins, the shielded portion of the resin is hardened as a result of the self sustaining thermal reaction initiated by the UV radiation even though the shielded portion of the resin is never irradiated directly. As a result, the cationic initiated systems cure or react more completely and as a result do not suffer from the tacking and flaking problems associated with free radical radiation curable resins.
In the invention, to coat the sewing thread, the sewing thread is passed through a cavity in a coating apparatus which contains the radiation curable material under pressure. The radiation curable material is applied to the thread in the cavity using a “contact coating” process in which the pressurized radiation curable resin is applied to the exterior of the sewing thread as the sewing thread is contacted by a surface so as to impregnate resin into the periphery of the sewing thread. In one embodiment of the invention, contact coating is achieved by employing a coating die having an orifice of smaller diameter than the diameter of the sewing thread. Alternatively, a deformable porous media can be provided in the die cavity so that it surrounds and contacts the sewing thread as it passes through the cavity. As a result of contact coating, the resultant sewing thread exhibits a thin layer of radiation curable material that has been impregnated into the periphery of the sewing thread.
Following curing of the radiation curable coating, the sewing thread of the invention differs structurally from conventional organic solvent based coated sewing thread because the radiation curable composition is applied so that the composition penetrates into the periphery of the sewing thread, preferably to a depth of one to about three single filament layers (or diameters), and the peripheral filaments are bonded to each other and in some cases to the next interior level of filaments. Although the composition penetrates the thread, the degree of penetration is controlled to prevent the thread from becoming unduly stiff. Thus, a continuous sheath of resin is not formed around the sewing thread, in contrast with conventional coated sewing thread; instead, the coating extends into the periphery of the thread. This can advantageously minimize or prevent stripping of the coating caused by abrasive forces such as are encountered in sewing processes.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the features and advantages of the invention having been described, others will become apparent from the detailed description which follows, and from the accompanying drawings, in which:
FIG. 1 is a top view of an exemplary apparatus for coating sewing thread in accordance with the invention;
FIG. 2 is a side view of the apparatus of FIG. 1;
FIG. 3 is a cross sectional view of a sewing thread coating apparatus of the apparatus of FIG. 1, taken along line 3 — 3 thereof;
FIG. 4 is a partially broken top view of the coating apparatus of FIG. 3, taken along line 4 — 4 thereof;
FIG. 5 is an enlarged top view of the broken away portion of the apparatus of FIG. 4 illustrating a resin reservoir therein;
FIG. 6 is a greatly enlarged cross-sectional view of a cavity of the coating apparatus of FIG. 3, taken along line 6 — 6 thereof;
FIG. 7 is a greatly enlarged cross-sectional view of an alternative embodiment of a cavity of the coating apparatus of FIG. 3 illustrating the use of a porous, deformable contact media in the cavity;
FIG. 8 a cross-sectional view of an ultraviolet (UV) radiation curing chamber of the apparatus of FIG. 1, taken along line 8 — 8 thereof;
FIG. 9 is a top view of the UV radiation curing chamber of FIG. 8, taken along line 9 — 9 thereof;
FIG. 10 is cross-sectional end view of the UV radiation curing chamber of FIG. 8, taken along line 10 — 10 thereof;
FIGS. 11, 12 and 13 are photographs illustrating a perspective view of a coated sewing thread of the invention and further illustrate penetration of the coating into the periphery of the sewing thread;
FIG. 14 is a photograph illustrating a perspective view of a sewing thread prepared using a conventional solvent based coating system and illustrates how the conventional coating surrounds the thread without substantial penetration of the coating into the thread;
FIG. 15 is a photograph illustrating a perspective view of an abraded prior art sewing thread coated with a conventional solvent based system and illustrates stripping of the coating caused by abrasive forces such as are encountered in sewing processes; and
FIG. 16 is a photograph illustrating a perspective view of an abraded coated sewing thread of the invention and illustrates the absence of any substantial stripping of the coating.
DETAILED DESCRIPTION OF THE INVENTION
In the following, a detailed description of the preferred embodiment of the invention is given. It will be recognized that although specific terms are used, they are used in a descriptive and not in a limiting sense in that the invention is susceptible to numerous variations and equivalents within the spirit and scope of the description of the invention.
Referring to FIGS. 1 and 2, an exemplary process and apparatus for coating sewing thread in accordance with the invention is illustrated. FIGS. 1 and 2 illustrate a system for in-line coating of multiple threadlines. The skilled artisan, however, will appreciate that the invention can include coating more or fewer threadlines than illustrated.
The threadlines, designated generally as 10 , are directed from supply packages 12 into a coating apparatus, designated generally as 20 , via entry ports 22 . The threadlines can be preconditioned or pretreated to provide moisture levels desirable for a particular resin system, for example, by minimizing exposure of the threadlines to atmospheric humidity and/or removing moisture from the threadlines prior to coating. The threadlines can be preheated, for example, using a standard UV unit, prior to entry into the coating apparatus.
Typically, a threadline comprises one or more multifilament plies which are individually twisted in a first direction and then combined by twisting in an opposite direction to produce a multi-ply thread construction. The threadline, however, can include one, two, or more than three multifilament plies or other structures used to form sewing thread as will be apparent to the skilled artisan. The multifilament plies are typically composed of a relatively high tenacity multifilament continuous filaments such as nylon, polyester or the like. By way of illustration, the individual or single multifilament plies typically have a denier (decitex) within the range of from about 50 to about 500 denier (56-556 decitex). Thus, the thread illustrated in FIG. 1 (comprising three individual multifilament plies) typically has a total denier ranging from about 150 to about 2,000 denier (167 to about 2,222 decitex).
As illustrated in FIG. 2, a resin supply source 24 supplies a radiation curable composition (which also can be preheated) to a resin distribution manifold via line 26 and into coating apparatus 20 . As used herein, and as will be appreciated by the skilled artisan, the term “radiation curable composition” refers to compositions which photopolymerize or cure upon exposure to radiation. Generally the composition includes polymerizable compounds, including monomers, oligomers, polymers, prepolymers, resinous materials, and mixtures thereof, and a photoinitiator, which when exposed to a source of radiation, initiates a reaction of the polymerizable materials. The radiation curable composition may be polymerized to form homopolymers or copolymerized with various other monomers.
In the invention, the preferred polymerizable compounds cure cationically, and the photoinitiator generates a proton on exposure to radiation, typically ultraviolet (UV) radiation. This cation causes the polymerizable compounds to crosslink. The cationic cure is advantageous because it is self generating. In contrast, most radiation curable compositions that are widely used in commerce are cured via a free radical mechanism in which the photoinitiator generates free radicals upon exposure to radiation, which in turn attack and initiate polymerization of unsaturated polymerizable compounds. For the polymerization to take place, the composition must be exposed to the radiation source; once the radiation source is removed, the reaction stops because free radicals are no longer generated. Thus unreacted material can remain in the coating unless all of the coating is exposed to radiation. In such cases, the coating tends to flake and/or tack.
In contrast, the cationic initiated reaction is self generating, i.e., the reaction continues after the radiation source is removed. Such compositions can provide an improved protective coating for sewing thread because the composition can more fully cure, that is, essentially all available polymerizable components of the composition are reacted. As result, essentially no flaking is observed when the thread is used.
Preferred cationically curable compounds include epoxy resins. As the skilled artisan will appreciate, radiation curable compounds other than epoxy resins can be used in the invention so long as the curing or polymerization thereof is self sustaining after the reaction is initiated by exposure to radiation. Epoxy compounds or resins suitable for use in the invention include those materials having at least one polymerizable epoxy group per molecule, and preferably two or more such groups per molecule. The epoxides can be monomeric or polymeric, saturated or unsaturated, and include aliphatic, cycloaliphatic, aromatic and heterocyclic epoxides, and mixtures thereof, and may be substituted with various substituents, such as halogen atoms, hydroxyl groups, ether radicals, and the like.
Preferably the epoxide is a cycloaliphatic epoxide. Exemplary cycloaliphatic epoxides include diepoxides of cycloaliphatic esters of dicarboxylic acids such as bis(3,4-epoxycyclohexylmethyl)adipate, bis(3,4-epoxycyclohexylmethyl)oxalate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis (3,4epoxycyclohexylmethyl)pimelate, and the like. Other cycloaliphatic epoxides include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylates such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylcyclohexane carboxylate,- 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate, 3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexane carboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane carboxylate and the like. Commercially available cycloaliphatic epoxides useful in the invention include epoxides available from Union Carbide Corporation as the “Cyracure” series of materials, epoxides available from UCB Chemicals as the “UVACURE® series of materials, and the like.
Preferably the moisture content of the threadlines is controlled to maximize performance of a particular resin system. For example, the threadlines can be preconditioned or pretreated prior to coating to minimize moisture uptake and/or reduce moisture content. Alternatively, or in addition to preconditioning, the percent humidity of the coating environment can be controlled to maintain a percent relative humidity desirable for performance of a particular resin.
The cycloaliphatic epoxies can be used alone, as mixtures with one another, and as mixtures thereof with other types of epoxides, such as glycidyl type epoxides, aliphatic epoxides, epoxy resol novolac resins, epoxy phenol novolac resins, polynuclear phenol-glycidyl ether derived resins, aromatic and heterocyclic glycidyl amine resins, hydantoin epoxy resins, and the like and mixtures thereof. These epoxides are well known in the art and many are commercially available.
The epoxy can be present in amounts between about 99.9 and about 85 percent by weight of the composition.
Suitable photoinitiators include onium salts as known in the art for photoinitiating cure of epoxy resins. Such onium salts can have the general formula: R 2 I + MX n − , R 3 S + MX n − , R 3 Se + MX n − , R 4 P + MX n − , R 4 N + MX n − , wherein different radicals represented by R can be the same or different organic radicals containing 1 to 30 carbon atoms, including aromatic carbocyclic radicals containing 6 to 20 carbon atoms, which can be substituted with 1 to 4 monovalent radicals selected from the group consisting of C1-C8 alkoxyl, C1-C8 alkyl, nitro, chloro, bromo, cyano, carboxy, mercapto, and the like, and also including aromatic heterocyclic radicals including pyridyl, thiophenyl, pyranyl, and the like; and MX n − is a non-basic, non-nucleophilic anion such as BF 4 − , PF 6 − , AsF 6 − , SbF 6 − , HSO 4 − , ClO 4 − and the like as known in the art. The term “hetero” as used herein refers to linear or cyclic organic radicals having incorporated therein at least one non-carbon and non-hydrogen atom, and is not meant to be limited to the specific examples contained herein. Exemplary photoinitiators include triarylsulfonium complex salts, aromatic sulfonium or iodonium salts of halogen-containing complex ions, aromatic onium salts of Group VIa elements, aromatic onium salts of Group Va elements, and the like. Currently preferred photoinitiators include triarylsulfonium hexafluoroantimonate salts, triarylsulfonium hexafluorophosphate salts, mixtures thereof and the like. The photoinitiator is present in the radiation curable composition in conventional amounts, typically ranging from about 0.1% to about 15% by weight, based on the total weight of the composition.
Suitable radiation curable compositions are disclosed, for example, in U.S. Pat. Nos. 4,874,798; 4,593,051; and 4,818,776, the entire disclosure of each of which is hereby incorporated by reference.
In addition, the radiation curable composition can include a pigment capable of imparting color to the threadline. The pigment can be an organic or inorganic pigment, or a mixture thereof, as known in the art. Useful inorganic pigments include without limitation metallic oxides (iron, titanium, zinc, cobalt, chromium, and the like), metal powder suspensions (gold, aluminum, and the like), earth colors (siennas, ochers, umbers, and the like), lead chromates, carbon black, and the like and mixtures thereof. Useful organic pigments include without limitation animal pigments (rhodopsin, melanin, and the like), vegetable or plant pigments (chlorophylls, carotenoids, such as carotene and xanthophyll, flavanoids, such as catechins, flavones, flavanols, and anthocyanins, flavanones, leucoanthocyanidins, flavonols, indigo, and the like), synthetic organic pigments (phthalocyanone, lithos, toluidine, para red, toners, lakes, and the like), and the like and mixtures thereof.
FIG. 3 illustrates a cross-sectional view of coating apparatus 20 of FIG. 1 taken along line 3 — 3 . Coating apparatus 20 includes a horizontally split coating die 28 with upper and lower members 30 and 32 , respectively, each member having a generally elongate shape with a rectangular or square cross-section. Die 34 is provided with a plurality of cavities or reservoirs 34 which are each in communication with a corresponding threadline entry port 22 and a threadline exit port 36 . Lower member 32 of die 28 is also provided with a plurality of radial bores 38 , each in fluid communication with an individual reservoir 34 and with the resin distribution manifold via one of a plurality of lines 40 to allow the radiation curable composition from source 24 to be fed into each reservoir 34 . Each reservoir 34 preferably has a generally cylindrical shape which is tapered at the entry and exit ports, although other reservoir configurations can be used.
Each threadline enters the coating apparatus via a discrete entry port 22 into a reservoir 34 and then exits the coating apparatus via an exit port 36 . As best seen in FIGS. 5 and 6, the split coating die 22 is divided into the upper and lower members 30 and 32 along a plane that extends through the entry and exit ports 22 and 36 of each die cavity 34 . This construction allows easy threading at start-up of the coating process when the upper member 30 of the split die is removed. The threadlines can be alternatively threaded through the coating apparatus 20 using an aspirator or other suitable means.
Pressurized radiation curable composition is directed from resin supply source 24 through line 26 to the resin distribution manifold and into each reservoir 34 via lines 40 . As threadlines 10 pass through the coating apparatus, and in particular through reservoirs 34 filled with pressurized radiation curable composition, the threadlines are coated with the composition.
The pressure of the radiation curable composition within reservoirs 34 can vary, depending upon factors such as the working viscosity of the composition, the desired level of pickup, and the like. Advantageously, the composition is pressurized to assist with control of the desired level of pickup.
The inventors have also found that the invention can be used with a wide range of radiation curable composition viscosities, ranging from about 100 centipoise (cP) to about 8000 cP, and higher at room temperature. Preferably, the viscosity and pressure of the radiation curable composition within reservoir 56 are selected to provide a threadline pickup of about 1 to about 20 percent, and more preferably about 5 to about 12 percent. For example, in one advantageous embodiment of the invention, a radiation curable composition having a viscosity of about 500 to about 2000 cP is supplied within reservoir 56 at a pressure less than about 5 pounds per square inch (psi). Radiation curable compositions having higher viscosities can also be used in combination with higher pressures (for example, a viscosity of about 5000 to about 7000 cP at a pressure of about 30 to about 50 psi), to achieve comparable degree of resin pickup onto the threadline.
In addition to varying and controlling composition viscosity and pressure within reservoirs 34 to control pickup of the composition by the threadline, the coating process of the invention also includes a “contact coating” step to control pickup. As used herein, the term “contact coating” refers to applying the pressurized radiation curable composition to the exterior of the threadline within the coating apparatus 20 while also contacting the coated threadline with a suitable surface to impregnate the composition into the periphery of the threadline.
In one embodiment of the invention, each exit port 36 of coating die 28 has a diameter which is slightly smaller than the cross sectional dimension of each of the threadlines 10 . In this embodiment of the invention, the coated threadline contacts the edge of port 36 as the threadline passes therethrough. In another embodiment of the invention, a deformable porous media can be inserted into reservoir 34 which surrounds and contacts the threadline as it passes through the reservoir. For example, as illustrated in FIG. 7, a felt material 42 can be formed into a shape corresponding to the interior configuration of the reservoir 34 , although other conformable, porous media can also be used. In this embodiment of the invention, this contact in effect “wipes” the coated threadline so as to control pickup. As a result of the contact coating step, the resultant threadline exhibits a thin layer of radiation curable composition that has been impregnated into the periphery of the threadline to provide a coated sewing thread which is structurally distinct from conventional sewing thread, as described in more detail below. Impregnation can be controlled, however, so that the resultant thread is not undesirably stiff due to excessive penetration of the resin into the thread structure.
This contact coating step contrasts with conventional processes for coating continuous substrates. For example, typically sewing thread is immersed in a low solids content solution of the bonding agent, passed through cooperating rotating rolls to remove excess bonding agent, and then heated to evaporate the solvent. However, this process can result in undesirable levels of resin pickup, which can result in excessively thick coating sheaths, wasted material, and the like. The pressure of the nip can be controlled to remove excess resin, but excessive pressure can cause the resin to impregnate the thread. This is typically avoided because of the resulting increased stiffness.
On the other hand, conventional die coating processes for coating wires, optical fibers and the like with a radiation curable composition typically include directing the optical fibers through a coating apparatus which includes a cavity filled with a pressurized radiation curable composition. However, in contrast to the present invention, typical wire and optical fiber coating processes do not include a contact coating step. Instead, the exit orifice of the die has a diameter greater than the diameter of the fiber or wire and acts as a cylindrical doctor blade to apply a continuous sheathlike coating of the composition to the wire or optical fiber. Great efforts are taken in these processes to prevent the coated fiber from contacting or touching any surface to prevent harming the optic fiber.
Also as illustrated in FIGS. 3 and 4, coating apparatus 20 can include a clamping element 44 for applying substantially equalized clamping pressure to each reservoir 34 . The clamping element 44 includes a pair of pivoting arms 46 , each positioned for movement between a position that is non-aligned with the coating die 28 , and a die contacting and pressure distributing position aligned with an upper outer surface of the coating die (illustrated by the arrows in FIG. 4 ). Each arm preferably applies clamping pressure to the upper portion of the split die via a pressure distributing bar 48 attached thereto via suitable fastening means, such as a threaded bolt 50 .
When actuated, each arm 46 rotates from the noncontacting position inwardly towards coating die 28 until pressure distributing bars 48 rest upon an upper outer surface of the coating die 28 . The pressure distributing bars advantageously provides substantially equalized pressure across each cavity 34 so as to control and equalize pickup of resin by individual threadlines passing therethrough.
Returning again to FIGS. 1 and 2, after exiting the coating apparatus 20 , the coated threadlines 10 are directed into a radiation curing chamber 50 via a plurality of conventional guides, not shown. As illustrated in FIG. 8, radiation curing chamber 50 includes a housing 52 comprising a base 54 and a cover 56 mounted for movement about a pivot 58 . Disposed within the housing 52 is an elongate radiation source 60 oriented perpendicular to the path of the threadlines 10 , which emits radiation of a suitable wavelength and intensity to initiate cure of the radiation curable composition on the threadlines. The radiation source 60 is mounted in a reflecting chamber within housing 52 to focus radiation emitted by the radiation source about each threadline. In a preferred embodiment as illustrated in FIGS. 8 and 10, the reflecting chamber includes an upper focusing reflector 62 oriented in the direction of the threadlines and a single elongate bottom diffusing reflector 64 oriented in the direction of the radiation source 60 . Reflectors 62 and 64 can be formed of any of the types of material known in the art suitable for reflecting radiation.
The upper focusing reflector 62 includes a plurality of individual semicircular reflector cavities, each extending from a threadline entry port into the housing 52 to a threadline exit port out of the housing 52 , and each having a longitudinal axis parallel to the path of the threadlines 10 through the radiation chamber. The bottom diffusing reflector 64 (FIG. 10) is preferably a single channel shaped cavity having a longitudinal axis perpendicular to the path of the threadline through the radiation chamber. The radiation source 60 and the reflecting chamber, including top focusing reflector 62 and bottom diffusing reflector 64 , through which the threadlines travel are positioned so that substantially all of the periphery of the moving threadline is impinged by radiation emitted by the radiation source 60 . Although not required, the curing chamber 50 can be continuously flooded or purged with an inert fluid, such as nitrogen, argon, helium, and the like to prevent or minimize adverse effects on the curing due to the presence of oxygen in the curing chamber.
If desired, housing 52 can be adapted to receive a suitable monitoring device to monitor energy levels emitted by radiation source 60 , such as a probe 66 in FIG. 8 . In addition, the curing chamber can include an exhaust duct 68 and cooling vent 70 to exhaust heat generated by the process from the chamber and to introduce cooling fluid into the chamber to thereby control temperature within the chamber.
Although the curing chamber as illustrated includes one radiation source, more than one radiation source can be included within the chamber. Alternatively, as illustrated in FIGS. 1 and 2, more than one curing chamber, designated as chambers 72 and 74 , can be provided. In addition, although an elongate radiation source is illustrated perpendicular to the path of the threadlines, in an alterative embodiment of the invention, one or more elongate radiation sources can be used which are parallel to the threadlines.
The active energy beams used in accordance with the present invention may be ultraviolet light or may contain in their spectra both visible and ultraviolet light. The polymerization may be activated by irradiating the composition with ultraviolet light using any of the techniques known in the art for providing ultraviolet radiation, i.e., in the range of 240 nm and 420 nm ultraviolet radiation, or by irradiating the composition with radiation outside of the ultraviolet spectrum. The radiation may be natural or artificial, monochromatic or polychromatic, incoherent or coherent and should be sufficiently intense to activate polymerization. Conventional radiation sources include fluorescent lamps, mercury, metal additive and arc lamps. Variable irradiant platform lamps available from Fusion Systems, which emit a narrow wavelength band of 308 nm, are also advantageous in the present invention to more closely match the chemistry of the radiation curable composition. Coherent light sources are the pulsed nitrogen, xenon, argon ion- and ionized neon lasers whose emissions fall within or overlap the ultraviolet or visible absorption bands of the compounds of the invention.
The radiation time can depend on the intensity of the radiation source, the type and amount of photosensitizer and the permeability of the composition and the threadline to radiation. The threadline can be exposed to radiation for a period ranging from about 0.05 second to about 5 minutes. Irradiation can be carried out in an inert gas atmosphere but this is not required.
Returning to FIGS. 1 and 2, threadlines 10 exit the curing chamber(s), are directed between the nip of a capstan device defined by cooperating idle rolls 76 and 78 , and taken up via a plurality of individual winders 80 for storage. Alternatively, the threadlines can be directed to additional downstream processing.
Also as illustrated in FIGS. 1 and 2, a computer control system 82 can be used to monitor threadline tension and detect breakage of a threadline. If a break is detected, the control system can actuate a value to close off the specific resin supply line 40 to the reservoir 34 associated with the broken threadline to stop resin feed into the reservoir to minimize resin loss. The control system can also deactivate the power supply to the threadline supply and/or wind up rolls associated with the broken threadline. Additionally, the control system can also monitor the coating resin supply.
The resultant coated sewing thread of the invention differs structurally from conventional coated sewing thread. As noted above, the radiation curable coating is applied so that the resin penetrates into the periphery of the sewing thread, preferably to a depth of one to about three single filament layers (or diameters). As a result, the peripheral filaments of the sewing thread are bonded to each other and in some cases to the next interior level of filaments. However, even though resin penetrates the thread, the sewing thread can be flexible and is suitable for conventional applications, and in particular for highly demanding industrial applications, such as assembly of densely woven fabrics used to produce shoes, soft luggage, and the like, and other dense materials such as leather.
FIGS. 11 through 16 illustrate the structural differences between sewing thread coated with a conventional solvent system and sewing thread of the invention which is coated with a radiation curable, self sustaining polymerizable composition. FIGS. 11-13 are photographs illustrating perspective views of sewing thread coated in accordance with the present invention. As demonstrated by FIGS. 11-13, the resin penetrates into the periphery of the sewing thread for a distance of from one and up to about three filament diameters (and more in some cases), thus bonding the outer filaments to one another and to some of the immediately underlying interior filaments as well. Thus, in the coated sewing thread of the invention, the sheath or coating is integrated into the exterior filaments of the thread. Further, as illustrated by FIGS. 11-13, the thickness of the coating is not uniform, but rather can vary, for example, depending upon the degree of penetration of resin in a given location along the periphery of the thread. Further, for thread comprising more than one multifilament ply, the coating can fill in the gaps between plies, in contrast to thread coated with a solvent system in which the cast resin bridges the gap between plies. Still further, the thickness of the coating can vary depending upon the percent pickup, the denier of the thread, the number of filaments per cross section of the ply, and the like.
In contrast, as demonstrated by FIG. 14, which is a greatly enlarged perspective view of a solvent coated sewing thread (again using the Elvamide system), a continuous sheath of resin is formed around the sewing thread and does not extend substantially into the thread. In essence, the solvent based system is cast as a separate film surrounding the periphery of the thread, which remains as the continuous sheath after the solvent is evaporated.
FIG. 15 is a perspective view of an abraded sewing thread which was coated with a nylon solvent based system, commercially available as the Elvamide series from DuPont. When the sewing thread was subjected to an abrasion test that simulates abrasion applied to the thread by a sewing needle, the coating is removed as strips. These strips are sometimes visible as a white powder or flakes on sewn products. In contrast, as illustrated in FIG. 1G, when the coated sewing thread of the invention is subjected to the same abrasion conditions, minimal displacement of the coating is observed.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. | Processes for coating sewing thread using a radiation curable composition and the resultant coated sewing thread. Sewing thread is coated with a radiation curable composition, which exhibits a self sustaining cure after exposure to radiation. The composition is applied using contact coating techniques to coat and impregnate the thread with resin. The coated thread is then exposed to radiation to cure the coating. Because the cure is self sustaining, the composition more fully and completely reacts to form a coating with increased durability and reduced susceptibility to stripping or flaking during use in demanding industrial applications. | 3 |
PRIORITY
This application claims priority of U.S. Provisional Patent Application No. 61/328,770 filed Apr. 28, 2010 and U.S. Provisional Patent Application No. 61/376,364 filed Aug. 24, 2010 and hereby incorporates the same provisional applications by reference herein in their entirety.
TECHNICAL FIELD
The present disclosure is related to the field of apparatuses and methods for fracturing a well in a hydrocarbon bearing formation, in particular, down-hole valve subassemblies that can be opened to fracture production zones in a well.
BACKGROUND
It is known to use valve subassemblies placed in well casing that can be opened once the well casing has been cemented into place. These valve subassemblies or “subs” can use a ball valve seat mechanism that can receive a ball placed into the casing. Once the ball is seated in the valve seat, flow through the valve sub is cut off. The pressure of fracturing fluid injected into the casing will cause the closed valve seat mechanism to slide a piston forward in the valve sub thereby opening ports in the wall of the valve sub to allow the pressure of the fracturing fluid penetrate into a production zone of a hydrocarbon bearing formation. The ball valve seat mechanism can be comprised of varying sized openings. Typically, a number of the valve subs are placed in series in the casing at predetermined intervals in spacing along the well into the formation. The largest diameter valve seat is placed nearest the top of the well with progressively smaller diameter valve seats with each successive valve sub place in the casing string. In this manner, the further valve sub, the one having the smallest diameter opening can be closed by placing the matching sized ball into the casing, which can pass through all of the preceding valve subs, each having larger diameters than the valve sub being closed, until the ball reaches its matching valve sub.
One shortcoming of these known ball valve seat mechanisms is that they cannot be cemented into place with a casing string, as there is no way to clean or wipe the cement out of the valve seat mechanisms. These mechanisms have to be run on a liner with open hole packers in a well bore, which is more costly to carry out.
Another shortcoming is that the volume of fluid, and the rate of fluid flow, is constricted by the progressively decreasing diameter of the ball valve seat mechanism disposed in each of the valve subs, which becomes increasingly restricted with each successive valve sub in the well. While the number of these valve subs can be as high as 23 stages, put in place with a packer system, the flow-rate that can be obtained through these valve subs is not high, for example, a flow rate of 15 cubic meters per minute cannot be obtained through these valve subs.
It is, therefore, desirable to provide a fracturing valve sub that overcomes the shortcomings of the prior art.
SUMMARY
An apparatus and method for fracturing a well is provided. In one embodiment, the apparatus comprises a valve subassembly that is further comprised of a tubular valve body having upper and lower ends, the valve body comprising at least one port extending through a sidewall thereof nearer the upper end. In some embodiments, the cross-sectional area of the port or ports can be equal to the cross-sectional area of valve body inside diameter. In so doing, the apparatus can allow produced fluids to enter into the apparatus at or near the same rate of flow that the fluids can pass through the apparatus. The apparatus can further comprise a tubular piston slidably disposed within the valve body. The piston can move from a closed position where the at least port is closed to an open position where the at least one port is open. The apparatus can further comprise one or more shear pins disposed between the piston and the valve body to hold the piston in the closed position. When sufficient force is placed on the piston, the shear pins can shear away to allow the piston to move from the closed position to the open position.
The apparatus can also comprise a tubular sleeve disposed within the piston. The sleeve or the piston can comprise grooves disposed on an interior side wall thereof extending from an upper end to a lower end thereof. The grooves can be configured to receive a dart configured to engage the sleeve or the piston so as to close off the passageway extending through the apparatus and to apply downward force against the sleeve that, in turn, places the downward force on the piston to move from the closed to open position.
In operation, an apparatus can be placed in a casing string near a production zone in a well. In other embodiments, a plurality of the apparatuses can be placed at predetermined locations along the casing string to enable the fracturing of the well at a plurality of production zones disposed therein. The grooves disposed on the sleeve or the piston can be configured to allow keys disposed on a dart to either pass through the sleeve or piston, or to engage the sleeve or piston so at to open that particular apparatus. When a plurality of apparatuses are used in casing string, the apparatus nearest the top of the well can comprise sleeve grooves that are wider than the sleeve grooves of the next apparatus placed further down the casing string. Accordingly, each successive apparatus can comprise sleeve grooves narrower than the preceding apparatus. Therefore, the apparatus at the end of the casing string will have the narrowest sleeve grooves of all the apparatuses disposed in the casing string. Thus, when the dart for the last apparatus, that is, the dart with the narrowest keys, is inserted into the casing string and moved along by the pressurized fracturing fluid injected into the well following the dart, the keys of that dart can pass through the sleeve grooves of each apparatus that precedes the last apparatus. When this dart reaches the last apparatus, the dart keys can engage the sleeve grooves and hold the dart in place. The pressurized fracturing fluid contacts dart cups disposed on an upper end of the dart to apply downward force on the cups to engage the sleeve to thereby move the piston to the open position. Once the piston is in the open position, the pressurized fracturing fluid can pass through the valve port(s), breaking the casing cement to provide a path to the formation and then fracture the formation so as to allow produced fluids enter into the casing string through valve ports. As the dart keys can provide means to simply hold the dart in place against its corresponding sleeve until the pressurized fracturing fluid can contact the dart cups and, hence, the sleeve and piston, finer graduations in dart key width and corresponding sleeve groove width can be implemented. In so doing, the inventor believes that the number of apparatuses used in a single casing string can be in the range of 16 to 30 or more. In addition to this, the sleeve of each apparatus can have the same inside diameter from the first apparatus to the last apparatus in the casing string to thereby enable the same volume and flow rate of produced fluids through each apparatus as opposed to prior art devices.
In some embodiments, each apparatus can comprise a corresponding dart with keys configured to only engage the sleeve or piston grooves of that apparatus. The grooves of the apparatus can be configured into particular profiles that will only match a corresponding profile on a matching dart. As such, a dart can pass through an apparatus where the profile do not match. Matching profiles will allow the dart to lock into the grooves and the pressurized fracturing fluid contacts dart cup disposed on an upper end of the dart to apply downward force on the cup to engage the piston to thereby move the piston to the open position.
Broadly stated, in some embodiments, an apparatus is provided for fracturing a well, comprising: a tubular valve body comprising upper and lower ends defining communication therebetween, the valve body further comprising at least one port extending through a sidewall thereof nearer the upper end; a tubular piston slidably disposed in the valve body and configured to provide communication therethrough, the piston closing the at least one port in a closed position, the piston opening the at least one port in an open position; means for moving the piston from the closed position to the open position when a downward force is placed on the piston; and a tubular end cap disposed on the lower end of the valve body, the end cap configured to stop the piston when the piston moves from the closed position to the open position.
Broadly stated, in some embodiments, the apparatus further comprises a dart comprising a longitudinal shaft comprising upper and lower ends, the lower end comprising a key, the key configured to engage the grooves disposed in the moving means, the upper end comprising at least one dart cup configured to seal off communication through the piston when the key has engaged the grooves.
In some embodiments, a method is provided for fracturing a well in a formation, the method comprising the steps of: providing a valve sub apparatus and placing the apparatus in a casing string disposed in the well, the apparatus located near a production zone in the formation; placing a dart into the casing string; and injecting pressurized fracturing fluid into the casing string wherein the fracturing fluid moves the dart through the casing string into the apparatus until the keys of the dart engage the sleeve to place a downward force on the sleeve to move the piston from the closed position to the open position wherein the fracturing fluid can pass through the at least one port of the apparatus to fracture the formation.
Broadly stated, in some embodiments, a system of darts and keys for use downhole in a well is provided, the system comprising: at least one apparatus, the apparatus comprising: a tubular valve body comprising upper and lower ends defining communication therebetween, the valve body further comprising at least one port extending through a sidewall thereof nearer the upper end; a tubular piston slidably disposed in the valve body and configured to provide communication therethrough, the piston closing the at least one port in a closed position, the piston opening the at least one port in an open position; means for moving the piston from the closed position to the open position when a downward force is placed on the piston; a tubular end cap disposed on the lower end of the valve body, the end cap configured to stop the piston when the piston moves from the closed position to the open position; and at least one dart comprising a longitudinal shaft comprising upper and lower ends, the lower end comprising a key, the key configured to engage the grooves disposed in the moving means, the upper end comprising at least one dart cup configured to seal off communication through the piston when the key has engaged the grooves, where the dart key is configured to specifically engage the moving means of a particular apparatus and the key can be targeted to the particular apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross-sectional elevation view depicting a fracturing valve subassembly.
FIG. 2 is a side cross-sectional elevation view depicting the body of the valve subassembly of FIG. 1 .
FIG. 3 is a side cross-sectional elevation view depicting the end cap of the valve subassembly of FIG. 1 .
FIG. 4 is a side cross-sectional elevation view depicting the piston of the valve subassembly of FIG. 1 .
FIG. 5 is a top plan view depicting the sleeve of the valve subassembly of FIG. 1 .
FIG. 6 is a side cross-sectional elevation view along section lines A-A depicting the sleeve of FIG. 5 .
FIG. 7 is a side elevation view depicting the dart of the valve subassembly of FIG. 1 .
FIG. 8 is a front elevation view depicting an embodiment of the dart of FIG. 7 .
FIG. 9 is a front elevation view depicting an alternate embodiment of the key of the dart of FIG. 7 .
FIG. 10 is a side cross-sectional view depicting a well in a formation with a plurality of the valve subassemblies of FIG. 1 .
FIG. 11 is a perspective cut-away view depicting a further embodiment of a fracturing valve subassembly in a closed position.
FIG. 12A is a side cross-sectional elevation view depicting the fracturing valve subassembly of FIG. 11 in a closed position.
FIG. 12B is a side cross-sectional elevation view depicting the fracturing valve subassembly of FIG. 11 in an open position.
FIG. 13 is a perspective view depicting an embodiment of the dart of the valve subassembly of FIG. 11 .
FIG. 14 is a close-up side cross-sectional elevation view depicting the fracturing valve subassembly of FIG. 12A and a dart.
FIGS. 15A-15D are close-up side cross-sectional elevation view depicting possible embodiments of key profiles for the fracturing valve subassembly of FIG. 12A and the corresponding key profiles of the darts.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring to FIGS. 1 to 6 , an embodiment of fracturing valve sub 10 is shown. The major components of valve sub 10 comprise valve body 12 , end cap 16 disposed on a lower end of body 12 , tubular piston 20 slidably disposed within body 12 and tubular sleeve disposed within piston 20 . When assembled, piston 20 is held position within body 12 by shear pins 25 disposed in holes 24 . Each valve sub 10 can further comprise a dart 22 that corresponds to a particular valve sub 10 .
Referring to FIG. 2 , one embodiment of valve body 12 is shown in more detail. In the illustrated embodiment, body 12 can comprise ports 14 extending through the sidewall of body 12 nearer the upper end thereof. Ports 14 provide a means for pressurized fracturing fluid to pass through and fracture a production zone of a formation. In a representative embodiment, the total cross-sectional area of ports 14 can be approximately equal to the cross-sectional area of the inside diameter of valve sub 10 itself such that there is little or no flow restriction of fluids passing through ports 14 in or out of valve sub 10 . In one embodiment, body 12 can comprises holes 24 disposed below ports 14 for receiving shear pin 25 , as shown in FIG. 1 . In another embodiment, body 12 can comprise ratchet threads 26 disposed on the interior surface thereof. In a further embodiment, body 12 can comprise threads 27 disposed at a lower thereof for releasably coupling to end cap 16 , as shown in FIG. 1 .
Referring to FIG. 3 , one embodiment of end cap 16 is shown in more detail. End cap 16 can comprise threads 17 disposed on an upper end therefor for releasably coupling with threads 27 disposed on body 12 . In another embodiment, end cap 16 can comprise cogs 28 disposed on its upper end for engaging with piston 20 , as described in more detail below.
Referring to FIG. 4 , one embodiment of piston 20 is shown in more detail. As shown, piston 20 can comprise a tubular member further comprising one or more seal grooves 34 disposed along the length of piston 20 , the grooves extending circumferentially around piston 20 . Seal grooves 34 can be configured to receive o-rings or any other suitable sealing member as well known to those skilled in the art. In the illustrated embodiment, two seal grooves 34 are disposed at an upper end of piston 20 whereas another pair of seal grooves 34 can be disposed nearer the middle of piston and a single seal groove 34 disposed near the lower end of piston 20 . In one embodiment, piston 20 can comprise shoulder 21 disposed on the interior surface thereof for retaining sleeve 18 in position, as shown in FIG. 1 . Piston 20 can further comprise holes 36 disposed on the exterior surface thereof to receive shear pins 25 , as shown in FIG. 1 . In another embodiment, piston 20 can comprise ratchet ring 38 disposed around the lower end thereof, which is configured to engage ratchet threads 26 disposed on the interior surface of body 12 . In a further embodiment, piston 20 can comprise cogs 40 disposed on the lower end thereof, cogs 40 being configured to engage cogs 28 on end cap 16 .
Referring to FIGS. 5 and 6 , an embodiment of sleeve 18 is shown. In this embodiment, sleeve 18 can be comprised of a tubular member comprising peaks 30 disposed on one end thereof, and keyways 32 extending therethrough on an interior surface thereof. As shown in FIG. 1 , sleeve 18 is disposed within piston 20 sitting on shoulder 21 .
Referring to FIGS. 7 and 8 , an embodiment of dart 22 is shown. Dart 22 can comprise of shaft 23 , one or more dart cups 44 disposed on the upper end thereof and one or more keys 42 disposed nearer the lower end thereof, keys extending substantially perpendicular to shaft 23 . Dart cups 44 can be circular in configuration, when viewed from the top, or of any other configuration such that darts cups 44 can substantially contact the interior surface of piston 20 when pressurized fracturing fluid is injected into the well. In this embodiment, keys 42 can comprise an oval cross-sectional shape. In another embodiment, keys 42 can comprise a keystone shape, as shown in FIG. 9 . In some embodiments, dart 22 can be comprised of rubber, metal, a combination of rubber and material or any other suitable material, or other combinations thereof, as well known to those skilled in the art.
Referring to FIG. 10 , a cross-sectional view of a horizontal well comprising the apparatus described herein is shown. In this example, well 46 in formation 48 comprises well casing 49 comprising a plurality of valve subs 10 displaced along well 46 . In installing liner 49 , float shoe 50 can be run into well 46 where float shoe 50 comprises a float collar, a cement stage collar with a latching wiper plug and a hydraulic burst sub, as well known to those skilled in the art, followed by a section of casing, then followed by a valve sub 10 . This is then followed by another section of casing and another valve sub 10 , and so on. The number of valve subs 10 and the spacing between the valve subs to be determined by the size of formation 48 and the number of production zones 54 contained in formation 48 . Once well casing 49 is in place in well 46 , well casing 49 can be cemented in place. A wiper dart can then be pumped into well casing 49 with flush cleaning fluid to clean all valve subs 10 and keyways 32 contained in each valve sub 10 .
After well casing 49 has been set in well 46 and pressure tested, well casing 49 is then ready for stimulation. In other embodiments, the apparatuses and methods described herein can also be used with conventional open-hole packers and liner packers.
To stimulate well casing 49 , pressurized fracturing fluid can be injected into well casing 49 until the pressure of the fluid in well casing 49 reaches the burst pressure of the burst sub. Once the burst sub opens, the dart 22 for the valve sub 10 located at the end of well casing 49 can be inserted into well casing 49 . As described above, each valve sub 10 has a corresponding dart 22 , wherein the keys 42 of a particular dart 22 will only engage the keyways 32 of its corresponding valve sub 10 . The keys 42 of the valve sub 10 at the end of well 46 being the narrowest, with the keys 42 becoming progressively wider with each successive valve sub 10 disposed in well casing 49 towards the top of well 46 .
When the first dart 22 is pumped into well casing 49 with the pressurized fracturing fluid, the dart will encounter the first valve sub 10 with the keys 42 of the dart contacting sleeve 18 of that valve sub. Peaks 30 on the sleeve serve to turn keys 42 either clockwise or counterclockwise thereby guiding keys 42 through keyways 32 . As keyways 32 of each valve sub 10 are wider than the keyways of the valve sub 10 located at the end of well 46 , keys 42 of the first dart 22 will pass through the first valve sub 10 and each successive valve sub 10 until the first dart 22 reaches the last valve sub 10 where keys 42 land into and engage the keyways 32 of the last valve sub 10 . In so doing, the pressurized fracturing fluid causes the dart cups 44 to seat in piston 20 of valve sub 10 and cause a high-pressure seal. As noted above, dart cups 44 can comprise a circular shape to seal against piston 20 . In other embodiments, dart cups 44 can comprise any other shape that are configured to function equivalently to seal against piston 20 .
Once dart cups 44 are sealed against piston 20 , the hydraulic force of the pressurized fracturing fluid applies a downward force on piston 20 until the force exceed the shear force rating of shear pins 25 such that shear pins 25 shear thereby allowing piston 20 slide downwards from a closed position, where ports 14 are sealed off, to an open position where ports 14 are revealed. As piston 20 moves to the open position, ratchet ring 38 can engage ratchet threads 26 to lock piston 20 in place and to prevent piston 20 from sliding upwards to the closed position. In another embodiment, cogs 40 disposed on piston 20 can engage cogs 28 disposed on end cap 16 to prevent piston 20 from rotating within body 12 once in the open position.
Once dart 22 is in place in piston 20 , dart 22 plugs well casing 49 below valve sub 10 thereby directing fluid to flow through ports 14 to fracture cement casing 52 and production zone 54 in formation 48 . As all valve subs 10 have the same inside diameter, there is no restriction of flow throughout well casing 49 . Because the valve subs have the same inside diameter throughout the casing string, the valve subs 10 can be used on liners with open hole packers or it can be incorporated into a casing string that can be cemented into a well bore, as well known to those skilled in the art, unlike the prior art devices that can only be used on liners with open hole packers. Accordingly, using the valve subs 10 on a casing string that can be cemented in place can reduce the cost of producing substances from the well. In addition, because the valve subs 10 all have the same inside diameter, this can allow a fracturing operator to pump fluid and sand down well casing 49 at higher rates (for example, 15 cubic meters per minute) without any friction pressure or pressure drops that would otherwise exist using prior art devices due to restrictions arising from the narrow internal diameters of the prior art devices. After the first dart 22 has been placed to fracture the first production zone 54 , the dart 22 for the next valve sub 10 along well casing 49 can be placed to fracture the next production zone 54 . This process can be then be repeated for each successive valve sub 10 along well casing 49 . Fracturing at high fluid rates can now be a continuous process by pumping a dart to open each valve, which can dramatically reduce the fracturing time for each interval, that is, for each valve sub 10 .
Once the fracturing program for well 46 has been completed, coil tubing or conventional tubing can be run into well casing 49 with a mud motor and mill. An operator can then circulate fluid to the first valve sub 10 and set 1000 daN of string weight, as an example, so that the mill can grind up the dart 22 in the valve sub. In so doing, the operator will notice rubber and metal cuttings at a flow back tank based on the calculated fluid volumes per the depth of each valve sub 10 . After a few minutes, the mill will cut the dart and its keys into tiny pieces and move through the valve sub. The operator can then pull the mill up back through the valve sub, and then run back through the valve sub to ensure full drift inner diameter. The operator can then continue on to the next valve sub 10 and dart 22 . This process can be repeated until all darts 22 have been drilled out of the valve subs 10 . The operator can then pull the mill to the surface and well 46 will be ready for production.
Referring to FIG. 11 , in some embodiments, fracture valve sub 10 can comprise a valve body 12 and piston 20 without sleeve 18 . In some embodiments, circumferential grooves disposed along the inner wall of piston 20 can comprise key profile 55 . Key profile 55 can further comprise locking shoulder 56 . FIG. 12A shows an embodiment of fracture valve sub 10 in a closed position. FIG. 12B shows an embodiment of fracture valve sub 10 in an open position.
Referring to FIG. 13 , an embodiment of dart 22 with a dart profile 58 is shown. In some embodiments, more than one dart profile 58 can be disposed around the exterior circumference of dart 22 .
Referring to FIG. 14 , in some embodiments, key profile can be mirrored by dart profile 58 on dart 22 . In some embodiments, dart 22 can comprise biasing means to bias dart profile 58 towards the inner wall of piston 20 to engage key profile 55 and lock on locking shoulder 56 when dart profile 58 matches key profile 55 . In some embodiments, biasing means can comprise spring 60 , although it would be understood and appreciated by a person skilled in the art that any biasing means performing the same equivalent function can be used in place of, or in combination with, spring 60 .
Referring to FIGS. 15A, 15B, 15C, 15D , some embodiments of possible key profile 55 and dart profile 58 configurations are shown. It would be apparent to one skilled in the art that any shape or pattern of key or dart profile that can interlock and perform the same function can be used. It is contemplated by the inventor, and would be apparent to one skilled in the art, that this system of key and dart profiles can have a wide range of application. For example, the system can be used for pump-down bridge plugs for isolating intervals, or multiple acidizing tools or plugs.
In operation of the embodiments of fracture valve 10 depicted in FIGS. 11-15 , a dart 22 can travel through casing 49 until it reaches a matching key profile 55 , and can latch into piston 20 , locking at shoulder 56 . The top of dart cup 44 on dart 22 can form a seal within valve body 12 . As noted above, dart cups 44 can comprise a circular shape to seal against piston 20 . In other embodiments, dart cups 44 can comprise any other shape that are configured to function equivalently to seal against piston 20 . This seal can create a hydraulic pressure on locked dart 22 and piston 20 . With a seal formed, shear pins 25 can shear under the pressure and piston 20 will be allowed to travel with the dart 22 into an open position, for example, as shown FIG. 12B . As piston 20 travels down well, it can either ratchet with a ring and a ratchet thread to remain in an open position as described above, or it can latch with a set of latching fingers 62 into the open position. Once fracture valve sub 10 is in an open position, ports 14 can be open to allow fracturing fluid to be released. This system can allow for a full fracturing diameter to the well surface during the fracturing operation.
As described above, each valve sub 10 can have a corresponding dart 22 . The dart profile 58 of a particular dart 22 will only engage the key profile 55 of its corresponding valve sub 10 . As depicted in FIGS. 10, 15A, 15B, 15C, and 15D , sets of fracture valve subs 10 and sets of darts 22 can be used where key profile 55 and dart profile 58 are varied such that shoulder 56 is located in different positions in each key profile 55 .
When the first dart 22 is pumped into well casing 49 with the pressurized fracturing fluid, the dart can encounter the first valve sub 10 with dart profile 58 contacting key profile 55 . If the profiles do not match, the dart 22 will not lock and it will progress down well until it meet a valve sub 10 with a key profile 55 that is complimentary to the dart profile 58 of that particular dart 22 .
After the first dart 22 has opened first valve sub 10 to fracture the first production zone 54 , the dart 22 for the next valve sub 10 along well casing 49 can be placed to fracture the next production zone 54 . This process can be then be repeated for each successive valve sub 10 along well casing 49 . Fracturing at high fluid rates can now be a continuous process by pumping a dart to open each valve, which can dramatically reduce the fracturing time for each interval, that is, for each valve sub 10 .
In some embodiments, once the fracturing program for well 46 has been completed, conventional removal tools, as well known to those skilled in the art, can then be inserted in the tubing string to retrieve any darts. Darts 22 can be retrieved individually, in groups, or all at once. In some embodiments, dart 22 can comprise a latch (not shown) disposed at its lower end so that it can contact and connect with a further downstream dart. Latched darts can then be pulled to surface together. In some embodiments, dart 22 can comprise bypass outlets disposed on shaft 23 to assist in breaking any seal that was created by cup 44 and facilitate the removal of dart 22 . The removal of the darts 22 can then allow for a full drift inner diameter of the well. In some embodiments, removed darts 22 can be reused to open closed valve subs 10 .
Following the removal of dart 22 , an operator can then shift valves 10 to a closed position and well 46 can be ready for production. Fracture valve sub 10 can be allowed to shift closed with a conventional shifting tool, as well known to those skilled in the art, after dart 22 has been removed. The shifting tool can allow for a locking of the piston 20 in a closed position in the absence of the shear pin. In some embodiments, fingers 62 can engage profile gap 64 on interior of valve body 12 in order to relock shifted piston 20 into a closed position, so that valve 10 may be reused.
Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the invention is defined and limited only by the claims that follow. | An apparatus and method is provided for fracturing a well in a hydrocarbon bearing formation. The apparatus can include a valve subassembly that is assembled with sections of casing pipe to form a well casing for the well. The valve subassembly includes a sliding piston that is pinned in place to seal off ports that provide communication between the interior of the well casing and a production zone of the formation. A dart can be inserted into the well casing and propelled by pressurized fracturing fluid until the dart reaches the valve subassembly to plug off the well casing below the valve subassembly. The force of the fracturing fluid against the dart forces the piston downwards to shear off the pins and open the ports. The fracturing fluid can then exit the ports to fracture the production zone of the formation. | 4 |
FIELD OF THE INVENTION
The present invention relates to a system for delivering warm fluids, for example a hot water system.
BACKGROUND OF THE INVENTION
The demand for hot water from a hot water system may vary considerably during the day. For a domestic system, there will be long period where no hot water is being drawn interspersed with much shorter periods where hot water is demanded, for example for showers or baths. Generally speaking, two alternative approaches to providing hot water are taken. The first approach, as shown in FIG. 1 , is to use a boiler 2 to heat a tank of water 4 via a heat exchanger 6 . Thus a relatively low capacity boiler is able to heat a reservoir of water within the tank 4 to an acceptably high temperature. When a user wishes to use the water, for example to run a bath, hot water is drawn off through an outlet pipe 8 at the top of the tank and cold water 10 is admitted to the bottom of the tank. Typically the cold water 10 comes from a separate header tank although in principle it can also come from direct connection to the cold main supplying the dwelling. In a domestic installation the boiler 2 may also have a heating hot water outlet and heating water return pipes 12 and 14 , respectively, such that the boiler can heat the dwelling via a radiator system.
An alternative approach which is also common in domestic hot water and heating systems is the combination boiler as shown in FIG. 2 . Here the store of preheated water is dispensed with and instead, when it is desired to use hot water, cold water is received by the boiler 20 directly from the cold water main 22 and is heated, in real time, within the boiler and output at a hot water outlet 24 . The combination boiler 20 also has a heating water outlet and heating water return 12 and 14 .
Each system has its own advantages and disadvantages. The system shown in FIG. 1 provides a plentiful supply of hot water, but once the water in the tank has been used, or rather exchanged with cold water, then there is a considerable delay before the water in the tank gets reheated to an acceptable temperature. The combination boiler system shown in FIG. 2 provides instantaneous supplies of hot water, but the flow rate of hot water is typically considerably restricted compared to the arrangement shown in FIG. 1 .
These systems are also used on a commercial scale, for example in hospitals and leisure centres. In such arrangements there is generally a background level of substantially constant (mean) hot water usage, but otherwise similar considerations apply. Therefore, in order to satisfy the peak demand that is likely to be expected either large storage vessels are required such that the water in them can be heated when the boiler has a spare capacity to do so, or alternatively the boiler must be rated for the maximum expected demand and hence a larger and more expensive boiler system is required which generally runs at below its peak capacity.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a hot fluid system comprising:
a hot fluid heater having an inlet and an outlet; a storage vessel; storage vessel heating means for heating the fluid in the storage vessel; a mixing valve having a first inlet for receiving fluid to be heated from a fluid supply, a second inlet for receiving fluid from the storage vessel, and an outlet for supplying fluid to the inlet of the fluid heater; and a controller; wherein the controller is arranged to monitor the heater's performance and to operate the mixing valve to blend the fluid from the fluid supply with fluid from the fluid storage vessel for supply to the heater.
It is thus possible to provide a heating system, for example for water, in which warm water can be blended with cold water, typically from the cold main, to raise the water temperature at the inlet to a water heater. This reduces the temperature rise that the water heater needs to impart to the water in order to obtain a target temperature. Since the product of the temperature rise and the flow rate through the water heater is a constant once the water heater has reached its maximum heating capacity it follows that a higher flow rate through the water heater can be maintained while warm water is available from the water storage vessel.
By having a store of pre-warmed (or preheated) water, and by being able to control the rate at which the pre-warmed water is mixed with the cold main, it is possible to enable the water system to cope with short term high flow rate demands for hot water which would be well beyond the capability of the water heater to service if it received its water solely from the cold main.
Preferably the water heater is a combustion boiler, and most preferably is a “combination” boiler where heated water at the output of the boiler is intended for direct delivery to one or more hot taps.
Advantageously a flue gas heat recovery system is provided for recovering heat from the flue gases of the combustion boiler and this heat is used to warm the water in the water storage vessel. A heat exchanger may also be provided in the water vessel which is connected to the boiler output such that at times of low hot water demand the water heater can be used to raise the temperature of the water in the water storage vessel.
Advantageously the flue gas heat recovery system includes a storage system and the stored heat can be used to preheat the cold water passing through the flue gas heat recovery system, the water then entering the storage vessel when hot water is drawn off via a tap.
Preferably the mixer is a mixing valve. The action of the valve is responsive to an output of the controller.
The blending may be a function of the demand placed on the heater. Therefore at low flow rates a controller may determine that little or no warmed liquid should be mixed with the inlet supply as the temperature rise is well within the capacity of the heater alone. However, as the demand increases due for example to an increased flow rate, then the controller may increase the proportion of warmed liquid in the blend such that the temperature rise that needs to be achieved by the heater is reduced.
In an alternative embodiment, the valve may be operated so as to achieve a target water temperature for supply to the heater. In such an installation the valve may be a thermostatically controlled mixing valve.
According to a second aspect of the present invention there is provided a method of operating a liquid heating system, the heating system comprising: a heater having an inlet and an outlet; a storage vessel; storage vessel heating means for heating liquid in the storage vessel; a mixing valve having a first inlet for receiving liquid to be heated from a liquid supply, a second inlet for receiving liquid from the storage vessel, and an outlet for supplying liquid to the inlet of the heater, wherein the mixing valve is adopted to blend liquid from the liquid supply with liquid from the storage vessel.
BRIEF DESCRIPTION OF THE FIGURES
Embodiments of the present invention will further be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 schematically illustrates a prior art hot water system having a hot water cylinder;
FIG. 2 schematically illustrates a prior art hot water system utilising a combination boiler;
FIG. 3 schematically illustrates a hot water system constituting a first embodiment of the present invention;
FIG. 4 schematically illustrates a hot water system constituting a second embodiment of the invention; and
FIG. 5 schematically illustrates a heat recovery device that may be used to recover heat from the exhaust gas of the boiler.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 3 schematically illustrates an embodiment of the present invention. A water heater 30 , which typically is a combination boiler, has a cold water inlet 32 and a hot water outlet 34 . The boiler will also have a fuel supply inlet (not shown) and heating water out and return pipes for supplying a radiator based heating system (also not shown for clarity). In use the combination boiler 30 burns a fuel, such as gas, and the waste combustion gases are exhausted via a flue 36 .
Cold water for heating by the boiler is supplied by a water source 40 , which is typically a direct connection to the cold water main. It can be seen that the cold water can flow along two branches. A first cold water branch flows to a first input 42 of a controllable mixer or blending valve 44 . A second cold water branch 46 flows from the cold water main 40 , through a heat exchanger 47 and into a water storage vessel 50 .
An outlet of water storage vessel 50 is provided to a second input 46 of the mixing valve 44 . An output 48 of the mixing valve 44 is connected to the cold water input 32 of the combination boiler 30 . The water storage vessel 50 is also connected to an expansion chamber 60 and a pressure relief valve 62 as is known to the person skilled in the art, so as to avoid pressure build up within the vessel, although these components may be omitted if back flow of water into the cold main is possible (and legal), thereby ensuring that the internal pressure within the water storage vessel 50 is the same as the cold mains pressure. Alternatively a vented tank fed from a header tank may be used.
The heat exchanger 47 is provided in the path of the hot flue gases such that water entering the water storage vessel from the cold main passes through the heat exchanger 47 and receives heat from the hot flue gas. A secondary heating coil 74 may also be provided such that the boiler itself can be used to heat the water in the storage vessel 50 .
In an alternative configuration, shown in FIG. 4 the cold water main corrects directly to the water storage vessel 50 and the heat exchanger coil 47 is configured such that it delivers heat to the storage vessel 50 . In this configuration, heat can be provided to the water in the storage vessel 50 via a further heat exchange coil 68 . The water flow is driven by a pump 70 . In this configuration heat can be delivered to the vessel all the time that the boiler 30 is combusting fuel. Additionally, a secondary heating coil 74 may be provided within the vessel 50 such that the boiler 30 can itself be used to warm water within the vessel 50 . Typically a boiler may spend a considerable time in a standby mode or a space heating mode, and hence indirect heating of the water in the vessel 50 via the coils 74 and/or 68 should enable the water temperature inside the vessel 50 to achieve a temperature of 65° C.
In each embodiment, the blending valve 44 is responsive to a controller 80 which controls the position of the valve and hence the ratio of water directly from the cold main compared to water from the storage vessel 50 which is admitted to the boiler 30 . The controller 80 may be an integral part of the boiler's controller or may be in communication with it in order to receive data concerning the boiler's performance, and in particular whether the boiler is operating at or near full capacity. The controller 80 may also receive data from temperature or flow rate sensors in the output line 34 although these sensors could be internal to the boiler and might already be provided for the use of the boiler controller.
When the boiler is operating in a heating mode, waste heat exiting through the flue gases is recovered by the heat exchanger 47 . Where the recovery system 47 has a heat storage capability itself, for example as will be described later, then the configurations of FIG. 3 or 4 are equally appropriate. However if the heat exchanger 47 does not have its own heat storage capability, then the configuration shown in FIG. 4 is more appropriate and the recovered heat can be used to warm the water in the storage vessel 50 .
The controller can work either to conserve the hot water in the vessel 50 to reserve it only for meeting peak loads, or it can be arranged to use the water from the vessel 50 whenever hot water is required. This is a design choice depending on the requirements of a particular installation.
Suppose initially that keeping the water to meet peak flow is the primary requirement. When the boiler is operating in a hot water mode, then the rate of water flow through the boiler is measured or inferred from the boiler's own controller and whilst the boiler is able to accept the demanded flow rate entirely from the cold water main and lift it to the desired temperature, then the controller 80 sets the mixing valve 44 such that all, or substantially all, of the water supplied to the boiler comes directly from the cold main. However, as the demanded rate of flow through the boiler increases, there will eventually become a point where the boiler is operating at its maximum capacity. It is assumed, at this stage, that the output temperature from the boiler is still at the target temperature. This flow rate depends, to some extent, on the temperature of the water coming in from the cold main 40 . If the users of the system now demand more hot water then the product of the flow rate and the required temperature rise will exceed the capacity of the boiler and, in the prior art combination boiler systems, the hot water temperature at the output 34 would begin to fall. However in the present invention, the onset, or a near onset of this condition is detected by the controller 80 and the blending valve 44 is operated so as to admit some of the warmed water from the storage vessel 50 . The mixing of the incoming cold main with some of the warmed water from the storage vessel 50 naturally causes an increase in the temperature of the water arriving at the boiler inlet 32 and consequently the temperature rise that needs to be imparted by the boiler is reduced. This means that the hot water system can service hot water demands where the flow rate is in excess of the capacity of the boiler to raise the water temperature at that flow rate from the cold main temperature to the desired output temperature on its own. Clearly this additional demand can only be serviced whilst there remains a store of warm water within the storage vessel 50 . Once that store is depleted, then the temperature of the water entering the boiler returns to being that of the cold main temperature. However it can be seen that transient high demand conditions can be accommodated without degradation of the final output temperature from the hot water system. The duration for which these transient conditions can be serviced depends, primarily, to the size of the water store 50 and this is a free choice of the system designer. Suppose, for example, that a typical domestic combination boiler can raise ten liters of water per minute by 35° C. If the cold water main is at 10° C., then the ultimate hot water temperature at maximum flow rate is 45° C. Thus, if the user wanted to run a warm bath, they would be limited to filling the bath at 10 liters per minute. However, if in an embodiment of the present invention water in the storage vessel 50 has been previously heated to 50° (which is a reasonable target temperature) as flue gases may often be in this temperature range or higher, then this water can be mixed with the cold main. Therefore, if a user wishes to run a bath at a flow rate of 20 liters per minute and with a target temperature of 45° C., then we know that the boiler will only be able to achieve a temperature rise of 17.5°. This means that the water temperature at the inlet to the boiler must be raised to 27.5°. We can also see that if water from the hot water tank 50 is mixed with water from the cold water main at a ratio of 1:1, then the water temperature achievable at the inlet to the boiler is 30°. It can also be seen that, of the 20 liters per minute, 10 liters per minute would be derived directly from the cold main and 10 liters would be derived from the storage vessel 50 . Thus, if the storage vessel had a size of 100 liters, then this enhanced flow rate of 20 liters per minute could be sustained for 10 minutes.
The system designer has a choice of whether to wait until the boiler has reached maximum capacity before starting to mix water into the cold water input, or whether the blending is started earlier, for example when the boiler reaches 80 or 90% of its maximum capacity depending on considerations of boiler efficiency and the like. Similarly the controller 80 could merely be responsive to the output temperature of the boiler once a certain minimum flow rate has been exceeded, and may then operate the mixing valve within a closed loop control system.
On the other hand, the mixing valve may draw water from the store 50 at all hot water flow rates. This may be useful, particularly in a domestic environment, as a way of reducing fuel usage. Thus the boiler does not have to work so hard with warming hot water and the vessel is kept at temperature during the time when the boiler is working to provide space heating.
In alternative embodiments of the invention the mixing valve may be a thermostatic mixing valve that operates to regulate the water temperature to the inlet of the boiler to a target temperature, for example in the range of 25 to 30° C. It should be noted that where the storage vessel 50 and the mixing valve are placed before an unmodified boiler, then safety systems within the boiler may cause the boiler to shut down (or refuse to light) if the water inlet temperature to the boiler is too great.
Currently preferred embodiments of the invention using a thermostatic mixing valve seek to achieve mixing ratios of between 2:1 and 3:1 (cold water to hot water) to achieve boiler inlet temperatures of around 25° C. plus or minus a few degrees. Such mixing valves are readily available and give rise to simple but well behaved implementations of the present invention.
FIG. 5 schematically illustrates a heat recovery unit for recovering heat from the flue gases which is suitable for use with the embodiments shown in FIG. 3 or 4 because the recovery device includes its own thermal storage capability.
The heat exchanger comprises a heat exchange pipe 102 which is bent into a helical coil portion 104 so as to provide a large pipe surface area within a compact volume. The helical portion 104 of the pipe is disposed within a double walled vessel 106 . An inner wall 108 of the double walled vessel 6 defines a channel 110 which is open at both ends and through which hot gas flue gases can flow. A volume 112 defined between the inner wall 108 and an outer wall 114 of the double walled vessel 106 is filled with water 116 so as to form a thermal store.
A reservoir 120 having a closed lower end is coaxially disposed within the gas flow path. The reservoir 120 contains water 122 and hence the hot flue gases flowing along the channel 110 give out the heat to both the water 116 enclosed within the double walled vessel 106 and also the water 122 enclosed within the reservoir 120 . A flange 124 extends radially outwards from the top of the reservoir 120 passing over the upper surface of the vessel 106 and joining with a further wall 126 which envelopes the exterior wall 114 of the vessel 106 . The flange 124 and wall 126 serve to define a further gas flow path which now cause the hot flue gases from the boiler to travel over the top of the vessel 106 and then down the outside of the vessel 106 thereby giving further heat exchange possibilities. Once the gases reach the bottom most edge 128 of the wall 126 they are then allowed to enter into a further flue gas channel 130 which ducts the gases towards an exit pipe 132 of the heat exchanger.
Optionally apertures 133 can be formed in the walls 108 and 114 of the vessel 106 . These allow the maximum level of water within the vessel 106 to be defined if, for a given boiler, it is desirable to have the amount of water reduced compared to the maximum volume of the vessel 106 . Similarly apertures could be formed in the reservoir 120 to limit its maximum volume of water.
As the flue gases pass over the surfaces of the heat exchanger, the gas is cooled. This can give rise to the formation of condensation within the heat exchanger, and the point that this starts to form will vary depending on operating parameters of the boiler, external temperature, water temperature and so on. This condensation can be used to advantage. An uppermost wall 140 of the vessel 106 is dished so as to form a collecting region, and apertures are periodically formed in the dished wall 140 to allow condensation which collects on the wall 140 to flow into the interior of the vessel 106 thereby ensuring that the vessel 106 remains topped up with water whilst also allowing the vessel to remain vented, thereby avoiding any potential dangers from pressure build up should excessive heating occur. Similarly condensation occurring within the outlet pipe 132 can fall under gravity into the interior of the reservoir 120 thereby topping up the water level 122 ensuring that that secondary thermal store also remains continuously full.
Optionally, a diffuser may be provided in the inlet gas path from the boiler so as to ensure that the gas is equally distributed over the interior wall 108 of the vessel 106 . The diffuser may be formed by an inclined wall 145 which may extend from or at least be in contact with the bottom surface of the reservoir 120 . The vessel 106 may have its profile altered in order to form co-operating surfaces 148 thereby further enhancing heat transfer into the heat exchanger by virtue of heat flow across the surface 148 . In an alternative embodiment the vessel 106 may rest upon a profiled ring which is chamfered so as to define the surface 148 . The heat exchanger is enclosed within a housing 150 which itself may be further enclosed within a second housing 152 with the gap between the housing 150 and 152 defining an air inlet path for gases to the boiler, thereby ensuring that air admitted into the boiler for combustion is itself pre-warmed further enhancing the efficiency of the boiler, and also ensuring that the exterior surface of the heat exchanger remains cool, for example to the touch, since the boiler will be installed in a domestic environment.
Thus, as in the case shown in FIG. 3 , even if water is not passing through the heat exchange coil the hot flue gases can give water up to the thermal stores within the flue gas heat recovery device.
It is possible to provide an inexpensive modification to the hot water system which enables a boiler to supply enhanced flow rates of hot water.
Although the invention has been described in the context of heat water, it is equally applicable for heating other fluids, such as food, oils, chemicals and so on.
This invention may also be used in multi-boiler installations where, while hot water is available from the storage vessel, it may be blended with cold water and used by two or more boilers to supply hot water. However, once the store of warmed water in the vessel 50 is depleted, one or more of the boilers may be tasked with re-warming it whilst the other boiler services the hot water draw in a conventional manner. | A fluid system is provided comprising: a heater having an inlet and an outlet; a storage vessel; storage vessel heating means for heating the fluid in the storage vessel; a mixing valve having a first inlet for receiving fluid to be heated from a fluid supply, a second inlet for receiving fluid from the storage vessel, and an outlet for supplying fluid to the inlet of the heater; and a controller wherein the controller is arranged to monitor the heater's performance and to operate the mixing valve to blend the fluid from the fluid supply with fluid from the storage vessel, for example, when a demand on the heater exceeds a threshold value. | 5 |
This is a division of application Ser. No. 930,972, filed Aug. 4, 1978, U.S. Pat. No. 4,188,716 issued Feb. 19, 1980.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus for gapping a slide fastener chain or removing a group of slide fastener elements from selected areas along a continuous length of slide fastener chain to provide "element-free gaps", the spacing between adjacent "gaps" largely determining the length of an individual finished slide fastener product.
2. Prior Art
Various methods and apparatus for gapping slide fasteners have been proposed heretofore. A typical example of the prior art methods and apparatus usually involves cutting the coupling head portions of the fastener elements and removing the cut pieces from the fastener tapes to leave gaps thereat free of fastener elements. To this end, the confronting, abutted edges of the tapes are required to be forced apart from each other widely enough to permit a punch to move therethrough. However, due to the tendency of the fastener tapes to resist the forcing apart or spreading open of their opposed element-carrying edges which have been brought into abutting engagement with each other, those portions of the tapes which lie between the locations of gaps to be formed and the withdrawal rollers disposed to guide the fastener chain out of the system, are prone to become elongated or stretched out. It has therefore been necessary, when predetermining the inter-gap spacing or intervals, to take into account such potential errors which may arise out of the elongation or stretching of the tapes. What makes this problem more complex is the fact that the material of the fastener tapes varies, it being a naturally occuring fiber in some instances or synthetic fibers in other instances, depending upon the garment or other articles to which the fastener is applied, or that the physical properties of the tapes also vary with whether they are woven or knitted, with the results that the rate of elongation of the tape under tensile force is variable with such varying conditions. Tape elongation is further subject to change with how rows of fastener elements are sewn to the support tapes, or even with the environmental conditions of the manufacture of fasteners. With conventional methods and apparatus, it has been difficult to determine the positions of "gaps" to be formed with reasonable accuracy, and it has been furthermore required to re-calibrate the equipment when the type of fastener chain changes.
SUMMARY OF THE INVENTION
Whereas, it is a primary object of the present invention to provide a method and apparatus for gapping a slide fastener chain at predetermined intervals along its length, which has been contrived to eliminate the aforesaid difficulties of the prior art.
It is a more specific object of the invention to provide an improved method which essentially comprises imparting a tendency to the stringer tapes to spread apart with minimum resistance at their opposed abutting edges where "gaps" are to be formed, and applying constant tension to the fastener chain between the feed and the withdrawal station so that "gapping" can take place exactly at predetermined intervals along a continuous length of slide fastener chain, and an improved apparatus tailored to carry this method into practice.
According to the invention, there is provided a method of producing a series of gaps free of fastener elements in and along a continuous length of slide fastener chain having a pair of oppositely disposed stringer tapes each carrying along one longitudinal edge a row of fastener elements with coupling head portions and connecting portions, which method comprises the steps of imparting a tendency to the fastener chain to spread the confronting edges of its tapes apart; applying constant tension to a length of said fastener chain; spreading the confronting edges of its tapes apart; removing a group of said fastener elements from the fastener chain; and withdrawing the fastener chain intermittently along a length corresponding to the spacing between adjacent gaps to be produced.
The above method is carried into practice by apparatus for producing a series of gaps free of fastener elements in and along a continuous length of slide fastener chain having a pair of oppositely disposed stringer tapes each carrying along one longitudinal edge a row of fastener elements with coupling head portions and connecting portions, which apparatus comprises: a feeding unit having a drive and a pressure roller for transporting the fastener chain at a predetermined rate of speed; a prespreading unit having oppositely disposed guide arms, one movable relative to the other, defining therebetween a channel for the passage of the fastener chain; said unit including a plunger adapted to enter between and spread apart the confronting edges of the stringer tapes while the latter are being advanced; a tensioning unit having a guide rail, a weighted roller with a bearing movable along said rail and a guide roller located adjacent said feeding unit; a gapping unit having a punch and a die coacting in severing a group of fastener elements across their coupling head portions and a pair of grippers adapted to grip and remove the connecting portions of said group of elements from the respective tapes; and a withdrawing unit having a drive and a pressure roller for withdrawing the fastener chain intermittently along a length corresponding to the spacing between adjacent gaps to be produced.
Other objects and advantages of the invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings which illustrate by way of example a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view utilized to explain the general process and equipment layout for gapping a slidefastener chain according to the invention;
FIG. 2 is a top plan view of a pair of coupled fastener stringers provided with a gap devoid of fastener elements;
FIG. 3 is a schematic view in side elevation of an apparatus for gapping a slide fastener chain according to the invention;
FIG. 4 is a schematic cross-sectional view taken on the line IV--IV of FIG. 3, which illustrates a mechanism for removing a group of fastener elements;
FIGS. 5 and 6 are schematic views in vertical section of the mechanism of FIG. 4, illustrating its operation;
FIG. 7 is a schematic cross-sectional view taken on the line VII--VII of FIG. 3; and
FIG. 8 is a schematic cross-sectional view taken on the line VIII--VIII of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and FIG. 1 in particular, there is schematically shown the steps of the gapping operation in accordance with the invention, in which a length of continuous slide fastener chain F is gapped at predetermined intervals while being transported under constant tension in the direction of the arrow. The fastener chain F is made up of a pair of oppositely disposed stringers F 1 and F 2 , each including a support tape T 1 (T 2 ) having secured to its edge a row of filamentary coupling elements E which may be of a meander or helical formation, the two stringers F 1 ,F 2 being shown coupled together. The rows of coupling fastener elements E each having a head portion Ea and connecting portions Eb are secured by sewing threads S. On its travel in the direction of the arrow, the fastener chain F moves initially past a pre-spreading station where the two interengaged stringers F 1 ,F 2 are imparted a physical tendency such that they can readily and easily spread apart when they are gapped at a later stage. The fastener chain F is then transported through a tensioning station where it is held under constant tension, and thence introduced into an element removing or gapping station where a group of fastener elements E is cut and removed from the fastener chain F, whereby the chain F is gapped; namely, provided with a tape section free of fastener elements E for purposes of the subsequent fastener finishing operation as well known in the art.
The method of gapping a fastener chain above described is implemented by an apparatus generally shown in FIG. 3. The gapping apparatus generally designated at 10 comprises essentially a gapping unit 11, a feeding unit 12, a pre-spreading unit 13, a tensioning unit 14 and a withdrawal unit 15, all operatively associated in a manner to be described hereafter. The gapping unit 11 shown mounted on the top of the machine frame 16 includes a pair of fastener chain guides (not shown) for holding the fastener chain F face up; namely, with an element-carrying side up, in a horizontal position, the guides having a projection adapted to spread apart the confronting edges T' of the stringers F 1 ,F 2 and abut against the fastener elements E.
The gapping unit 11 further comprises, as better shown in FIGS. 4 through 6 inclusive, a vertically movable cutting punch 17 having a punch head 17' and a stationary die 18 having a die groove 18', the punch head 17' constituting with the die groove 18' a coacting die cutter for severing the coupling head portions Ea of the fastener elements E.
The punch 17 is situated below and in vertically opposed relation to the die 18 and mounted movably within a guide member 19. It is vertically reciprocated by an actuator 20. A spring 21 is disposed in the guide member 19 for normally positioning the punch head 17' in registry with the projection of the fastener chain guide or in close proximity with the lower surface of the stringer tapes T 1 ,T 2 as shown in FIG. 4. The gapping unit 11 further comprises a pair of horizontally opposed grippers 22,23 which are disposed in criss-cross relation to the vertically disposed punch 17 and die 18. The grippers 22,23 are each constituted by an upper blade 22a,(23a) and a lower blade 22b,(23b) which are interconnected by a pin 24,(25). The upper blades 22a,23a are movable toward but normally spring-biased to be away from the corresponding blades 22b,23b.
The operation of the gapping unit 11 is illustrated in FIGS. 5 and 6, in which the punch 17 is moved by the actuator 20 upwardly and thrusted through the coupling head portions Ea of the fastener elements E on the intermeshed stringers F 1 ,F 2 , while the connecting portions Eb of the elements E are held by the grippers 22,23. As the fastener elements E are completely severed across the interengaged coupling heads Ea, the grippers 22,23 begin to retract horizontally away from the punch 17 and the die 18, taking along with them the residual element debris apart from the sewing threads S. The structural and functional details of such a gapping mechanism are basically well known, and hence will require no further explanation.
The feeding unit 12 essentially comprises a drive roller 26 and a pressure roller 27 for positively feeding the slide fastener chain F at a predetermined rate of speed. As better shown in FIG. 1, a pair of these rollers are provided for each of the two stringers F 1 ,F 2 in such a manner that they do not ride over or engage the beaded edges T' of interengaged stringers F 1 ,F 2 which have been given a tendency to spread apart at the pre-spreading unit 13.
The pre-spreading unit 13 is located in advance or upstream of the feeding unit 12 and arranged to receive the fastener chain F which has been oriented by guide rollers 29,30 to run substantially vertically with respect to the unit 13. As better shown in FIG. 7, the pre-spreading unit 13 comprises two guide arms 31 and 32 disposed in confronting relation and defining therebetween a channel 33 for the passage of the slide fastener chain F. The first guide arms 31 is pivoted at one end about a pin 34 and is provided at the other end with a fastener element guide 35 adapted to guide the rows of interengaged fastener elements E slidably therethrough. The second guide arm 32 is provided with a wedge-shaped plunger 36 for spreading apart the confronting, abutted edges T' of the stringer tapes T 1 ,T 2 .
The plunger 36, as better shown in FIG. 8, is tapered off progressively in the direction of entry of the fastener chain F so that the abutted edges T' of the tapes T 1 ,T 2 can be easily spread apart on passing therethrough. A stem portion 36' of the plunger 36 is slightly greater in width than the punch head 17', so that the stringers F 1 ,F 2 are imparted a tendency, while moving past the plunger 36, to reduce their resistance to open or facilitate the spreading apart of their closed edges during the subsequent gapping operation. Designated at 37 is a bolt-and-nut stopper which is adapted to adjustably set the clearance between the first and second guide arms 31,32. Designated at 38 is a spring-biased clamping member adapted to hold the two arms 31,32 in position. The pre-spreading unit 13 thus constructed is secured, as by bolt 39, to a guide bar 40 extending vertically from the frame 16.
The tensioning unit 14 is located between the feeding unit 12 and the gapping unit 11 and functions to apply and maintain a constant tension to the slide fastener chain F spanning between the feeding unit 12 and the withdrawal unit 15. The tensioning unit 14 comprises a vertically disposed guide rail 41 and a weighted roller 42 with a bearing 43 movable vertically along the rail 41, and further includes a guide roller 44 located adjacent the feeding unit 12. The rollers 42 and 44 are similar in construction to the drive and pressure roller pairs 26,27 of the feeding unit 12 in that they are all arranged to engage with the web portions of the tapes T 1 ,T 2 , not with the element-carrying beaded edges T' thereof which have been pre-spread.
At the extreme upper and lower ends of the guide rail 41 are provided an upper-limit sensing element 45 and a lower-limit sensing element 46, respectively.
In the event that the speed of feed of the fastener chain F at the unit 12 is higher than the speed of withdrawal of the chain F at the unit 15, the lower sensing element 46 on contact with the bearing 43 functions to cause the feed rollers 26,27 to stop. The feed rollers 26,27 are arranged to resume rotation when the bearing 43 of the weighted roller 42 is brought into contact with the upper sensing element 45. Thus, constant tension is applied to the fastener chain F by the weight of the roller 42, regardless of the drive system.
The withdrawal unit 15 comprises a drive roller 47 and a pressure roller 48 cooperating therewith in withdrawing the fastener chain F intermittently when a cycle of gapping operation is completed at the unit 11. The withdrawal unit 15 is movably mounted via frame member 49 on a horizontal guide bar 50 extending from the frame 16. The drive roller 47 is aligned with the guide roller 44 so that the fastener chain F moves properly into and out of the space between the punch 17 and the die 18 in the gapping unit 11. The position of the withdrawal unit 15 determines the spacing or distance between adjacent gaps G along the length of the fastener chain F. To set this spacing or distance, there is provided a sensing element 51 at the withdrawal unit 15 which is arranged to sense the arrival of the trailing end of the gap G thereby causing the drive roller 47 to stop. The distance indicated by "L" in FIG. 3 measures between the center of the punch 17 and the sensing element 51 and in effect determines the spacing between adjacent gaps G that is desired.
Although various minor modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of my contribution to the art. | A method of providing a slide fastener chain with gaps free of fastener elements at predetermined interval is disclosed, the method comprising imparting a tendency to the fastener chain to spread the confronting longitudinal edges of its opposed stringer tapes prior to removal of the fastener elements, and maintaining constant tension over a length of the fastener chain, whereby the gaps can be formed accurately at predetermined locations along the length of the fastener chain. A preferred form and construction of apparatus tailored to carry this method into practice is also disclosed. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to planar battery separators, flat-pack batteries and the methods of making same. More particularly, this invention concerns a planar battery separator comprising a nonwoven fabric disposed on and across an open hot melt plastic grid and wherein the portion of the fabric on the plastic grid is of a very low fiber density, facilitating a strong intra-battery seal thus prohibiting electrolyte leakage therefrom.
Planar or flat-pack batteries, for example, the LeClanche type battery, having recently become more widely used because of the "mini" product and package market in existence today. Planar batteries have found their way into computers, calculators, film-packs for instant cameras, and the like, and have received wide-spread acceptance. However, they seem to suffer some major drawbacks. For example, their shelf life is rather short due to electrolyte leakage therein during storage and use. This disadvantage is due primarily to faulty and incomplete seals within the battery pack. Unless the battery seal is complete, it results in many failures and much frustration.
Prior art attempts to correct this deficiency have included U.S. Pat. Nos. 3,701,690; 3,784,414; and 3,899,355. The first patent mentioned, U.S. Pat. No. 3,701,690 describes a battery having a sealant impregnated into the separator; U.S. Pat. No. 3,784,414 discloses a battery sealant carrier having adhesive patches impregnated therein; and U.S. Pat. No. 3,899,355 discloses a battery assembly utilizing a particular adhesive mass. However, none of these adequately solves the problem, and none describe or claim the invention disclosed herein.
SUMMARY OF THE INVENTION
A sheet of open-windowed hot-melt adhesive plastic defines a plurality of battery separators wherein the open windows have a web of nonwoven fibers disposed thereon which continues from one window portion to the next, however, that portion of the web crossing over the plastic areas between openings advantageously has an extremely low fiber density and those fibers are oriented substantially normal to the axis of a particular side of the opening. Because of this advantageous structure, individual battery separator can be bonded to similarly made electrodes using a plastic material therein and other separators in a rather easy and efficient manner and yet produce a more complete seal to the battery pack itself.
An object of this invention is to provide a nonwoven battery separator that is disposed in registration with a plastic frame there around that can be thermally sealed to other separators disposed on similar plastic frames and electrodes alternatingly disposed therein.
Another object of this invention is to provide a method of producing the nonwoven web in registration with the plastic frame in one operation.
Still another object of the instant invention is to provide a battery separator, wherein the nonwoven web constitutes the body of the separator, with a periphery of low fiber density areas disposed on the plastic frame that are oriented normal to the axis of the frame so as to facilitate a more complete bond of plastic to plastic.
Finally, it is also an object of the present invention to produce a battery assembly utilizing the nonwoven battery separator of this invention, that significantly reduces costs heretofore required in flat-pack batteries.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a flat-pack or planar battery assembly ready to be insulated with an overwrap;
FIG. 2 is a perspective view of the stacked battery assembly of FIG. 1 prior to binding and sealing the individual components thereof together;
FIG. 3 is a sectional view of a typical bimetal electrode that can be used in the battery shown in FIGS. 1 and 2;
FIG. 4 shows a perspective view of the battery separator described in the present invention;
FIG. 5 is a partial view of a plastic grid used to make the battery separator described herein;
FIG. 6 is a partial view of a nonwoven web disposed over and on the plastic grid of FIG. 5; and
FIG. 7 is a flow chart outlining the method of making the battery separator of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a flat-pack or planar battery 10 comprising a plurality of anodes and cathodes separated by nonwoven battery separators of this invention. All four sides of the assembly are bound with a thermal pressure binding technique to produce the planar battery assembly 10.
FIG. 2 shows an alternating stack of electrodes 21 and separators 22, stacked to the desired height depending on the voltage to be attained therewith. FIG. 3 shows a typical electrode 21 that could be used in this battery assembly wherein the anode 31 is a coating of manganese dioxide and the cathode 32 is a coating of zinc. The anode 31 and cathode 32 are coated on a conductive sheet 33 of hot melt plastic, or the like, that is impregnated with a conductive material, such as carbon. In this manner, as shown in FIG. 2, the battery assembly consists of a battery separator 22 on an electrode 21, as described above, separated by a second separator 22 on another electrode 21, and so on providing a stack of four separators and three duplex electrodes alternately disposed therein and two electrode end plates. A slightly oversized steel top sheet 23 provides the negative end of the battery and wraps around to the bottom of the assembly so that the negative and positive contacts are on the same side. The battery is then insulated with an overwrap, or the like. A stacked battery as described above would be a 6-volt battery; of course, the voltage of same could be increased or decreased accordingly, by adding or subtracting electrodes and separators. Such a 6-volt battery would be less than 0.15 inch thick and would measure about 31/2 inches long by about 23/4 inches wide. Thus, it has many applications in the mini-electronic market.
The prior art problems stemming from the leakage of the liquid electrolyte through the sealant impregnated edges is overcome herein by the use of a battery separator such as described and shown in FIG. 4. The battery separator 41 comprises a generally rectangular plastic frame 42 of a material such as Versalon 1117, a trademark for a low viscosity hot melt thermoplastic sheet of a polyamide resin material sold by General Mills Chemicals, Inc., of Minneapolis, Minn. Within the frame or grid 42, is disposed the nonwoven separator material 43 which consists of randomly disposed textile fibers. The edges of the separator material 43 that lie directly adjacent the plastic grid are substantially oriented in a direction that runs parallel to the contours of the grid. However, the fibers 44 of the separator material 43 that bridge onto and over the grid 42 are of extremely low fiber density and are oriented substantially in a direction normal to the axis of the respective sides of the grid. This construction of the separator 41 facilitates the leakproof binding of the components of the battery, while providing a battery of sufficient strength and thickness to achieve its purpose.
This advantageous battery separator 41 can be made in much the same manner as described in U.S. Pat. No. 3,969,561, of common assignee, wherein a biaxially oriented nonwoven fabric is produced. FIG. 5 shows a sheet of Versalon 1117, or the like, that has been made into a grid structure 51, having equal rectangular openings 52 cut therein so as to leave these openings 52 surrounded by plastic connecting frame elements 53. A continuous sheet of the plastic grid 51 is then disposed on a continuously moving and porous conveyor screen, such as described in U.S. Pat. No. 3,969,561. A suction means placed under the screen and grid cause a majority of the fibers in a fluid-borne stream of textile-length fibers, preferably containing a rather high proportion of thermoplastic fibers, to locate within the openings, as at 43, while simultaneously causing a small number or minority of fibers to bridge across the plastic frame elements at 44, being pulled by the suction on either side thereof. Generally, over 80% of the fibers in the fluid-borne stream locate within the openings in the grid. Thus, the bridging fibers 44 are oriented in the direction substantially normal to the axis of the frame element 42, while the fibers within said opening that are directly adjacent the grid are oriented in the direction substantially parallel to the axis of the grid. The remaining fibers within the opening are in substantial random orientation. At the interstices 45 of the frame elements the fibers are drawn by suction from four open areas and result in fibers oriented at an angle of about 45° to the axis of the adjacent low fiber density areas 44. The sheet of thusly formed separators then passes through or under a heating means, such as infra-red lights, so as to anchor the separators in place on the grid. The sheet of separators can be assembled in a number of ways. For example, sheets of electrodes as described in FIG. 3 can be alternately stacked with the sheets of separators to the desired height or voltage value. These stacked sheets can then be die cut, with heat and pressure, so as to form finished battery assemblies.
In another embodiment, the sheets of battery separators, anchored into registration with the plastic grids, having the anodes and cathodes disposed to the top and bottom thereof separated by the nonwoven, electrolyte saturated, material. These cells are then stacked, cut and bound together as described above.
FIG. 7 shows a flow chart outlining the method of making the separators and battery of this invention.
EXAMPLE 1
A typical example of the preferred embodiment of this invention comprises depositing a fluid-borne stream of a 50-50 blend of 5.5 denier 1/4 inch cut Vinyon fibers (a trade name for fibers of a polymer of vinyl acetate and vinyl chloride made by American Viscose) and 2.5 denier Creslan fibers (a trade name for an acrylic fiber made by American Cyanamid Company), onto a plastic grid disposed on a moving conveyor screen, said screen having a suction means disposed thereunder for aiding and assisting the advantageous disposition of the fibers onto the grid and being essentially as described in U.S. Pat. No. 3,969,561. The weight of such a formed fabric is approximately 50 grams/square yard. The grid may be of any flexible, thin, thermoplastic material such as versalon 1117, or the like. A majority of the fibers are located on the openings in the grid. The separator was heated in a hot-air oven at a temperature of 370° F. Since the area of nonwoven therein is about 7.5 square inches (approximately 3 × 21/2 inches), and the total weight of the fabric disposed on the grid is 50 grams/square yard, then each nonwoven separator will weigh approximately 0.29 grams/unit, and at 7.5 square inches/pad there are approximately 172 pads/square yard. The thusly formed separators were passed through a heating means at about 370° F for anchoring the nonwoven and plastic together, and are ready for subsequent use in the assembly of flat-pack batteries.
EXAMPLE 2
Another battery separator was made of a 25-75 blend of Vinyon and Orlon fibers (a trademark for an acrylic fiber made by E. I. duPont de Nemours and Company of Wilmington, Del.), wherein a separator material was made in the same manner as described in Example 1 and weighing 56 grams per square yard. The separator was made of 42 grams/square yard of 11/2 inch 1.5 denier Orlon fibers and 14 grams/square yard of 3 denier 1/4 inch cut Vinyon fibers and were heated in a hot-air oven at a temperature of 370° F. Again, since the area of nonwoven therein is about 7.5 square inches, there are approxiately 172 pads/square yard.
Because of the extremely low fiber density of the fabric across the grid portion of the separators, it is therefore not necessary to use a hot melt plastic material of a very high thickness. Separators made according to this invention can thus be securely made with integrity at a very low cost. Thus, it is possible to reduce the thickness and cost of the planar battery, while substantialy eliminating the leakage problem of prior art batteries.
Of course, the fibers in the nonwoven material used as the separator herein can be of any composition so long as at least 10% of thermoplastic fibers are present in the fiber blend so as to facilitate the bonding of the separators to each other and to the electrodes of the battery.
Since it is obvious that many modifications and embodiments can be made in the above-described invention without changing the spirit and scope of the invention, it is intended that this invention not be limited by anything other than the appended claims. | A novel battery separator for a flat-pack or planar battery is disclosed wherein a nonwoven fabric is disposed on and across a plastic frame or grid, the outer edges of the fabric being disposed on said plastic frame are of extremely low fiber density and being oriented predominantly in a direction normal to each side of the frames so as to facilitate the more complete thermal pressurized bonding of a stack of separators and similarly electrodes by a sealing of the outer edges of the respective plastic frames. A more complete seal is thus formed insuring against the leaking or escaping of the liquid electrolyte contained therein. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This non-provisional application claims priority from provisional applications U.S. Ser. No. 60/218,085 filed Jul. 13, 2000 and U.S. Ser. No. 60/261,332 filed Jan. 12, 2001.
FIELD OF THE INVENTION
[0002] The present invention comprises methods of treating various acute and chronic central nervous system disorders by the administration of FLAP or 5-lipoxygenase inhibitors.
BACKGROUND OF THE INVENTION
[0003] Acute and chronic brain injuries can activate resident microglia (resident macrophage-like cells found in the central nervous system) as well as recruit peripheral immune cells to injured brain regions that can exacerbate neuronal damage. Inflammatory processes can induce cell death by (a) the release of proteases and free radicals that induce lipid peroxidation, (b) direct cytotoxic effects or (c) by the phagocytosis of sublethally injured neurons. The attenuation of microglia and peripheral immune cell activation has been correlated with significant neuronal protection in pre-clinical studies of ischemia, traumatic brain injury, spinal cord injury and Alzheimer's disease.
[0004] Oxygenase enzymes like cycloxygenase and lipoxygenase can initiate the conversion of arachidonic acid to physiological important metabolites. Cycloxygenase (COX; prostaglandin H2 synthase) is responsible for the formation of prostaglandins and thomboxanes. See Versteeg, H. Van, van Bergen en Henegouwen, M. P. V., van Deventer, S. J. W. and Peppelenbosch, M. P. (1999). Cyclooxygenase-dependent signaling: :molecular events and consequences. FEBS letters 445: 1-5. Lipoxygenase is responsible for the conversion of arachidonic acid to leukotrienes. Lipoxygenases and Their Metabolites, Plenum Press, NY. Eds. Nigam and Pace-Asciak. (1999). It is hypothesized that prostaglandins are an important step in transducing immune stimuli into CNS responses. There are two known isozymes of COX currently known COX-1 (constituitively expressed) and COX-2 (induction in response to immune stimuli). It has been established that COX-1 and COX-2 are found to be induced and constituitively expressed in peripheral immune cells as well as brain, with neuronal expression of COX-2 being enhanced following various CNS insults including cerebral ischemia. Tomimoto, H., Akiguchi, I. Watkita, H., Lin, J. X., Budka, H. Cyclooxygenase-2 is also induced in microglia during chronic cerebral ischemia in humans. Acta Neuropathol (Berl) 1: 26-30 (2000).
[0005] However, little is known about the role of lipoxygenases (or subsequent metabolites including hydroxyeicosatetraenoic acids (HETEs), leukotrienes, lipoxines, and hepoxilins) in regulating brain inflammation or neurodegeneration. There are currently four known human lipoxygenases (5, 8, 12, and 15-lipoxygenase). All isoforms share a common substrate as well as oxygenase activity but differ greatly in sequence. Although, the role of prostaglandins and COX-2 in modulating inflammation and pain has been well elucidated, the importance of LOX enzymes (specifically 5-LOX or 5-lipoxygenase) in brain following injury is still unresolved. Simon, L. S. Role and regulation of cyclooxygenase-2 during inflammation American Journal of Medicine 106: 37S-42S (1999).
SUMMARY OF THE INVENTION
[0006] Thus, according to a first embodiment of a first aspect of the present invention is provided a method of modulating or inhibiting microglia activation comprising the administration to a human in need thereof a compound capable of inhibiting 5-LOX.
[0007] According to another embodiment of the first aspect of the present invention is provided a method of modulating or inhibiting microglia activation comprising the administration to a human in need thereof a compound capable of selectively inhibiting 5-LOX over COX-2.
[0008] According to another embodiment of the first aspect of the present invention is provided a method of modulating or inhibiting microglia activation comprising the administration to a human in need thereof a compound capable of inhibiting FLAP.
[0009] According to another embodiment of the first aspect of the present invention is provided a method of modulating or inhibiting microglia activation comprising the administration to a human in need thereof para-REV5901 (L-655,238), Bay-x-1005, ML-3000, NDGA or ZILEUTON®.
[0010] According to a first embodiment of a second aspect of the present invention is provided a method of inhibiting the release of pro-inflammatory substances from activated microglial cells comprising the administration to a human in need thereof a compound capable of inhibiting 5-LOX.
[0011] According to another embodiment of a second aspect of the present invention is provided a method of inhibiting the release of pro-inflammatory substances from activated microglial cells comprising the administration to a human in need thereof a compound capable of selectively inhibiting 5-LOX over COX-2.
[0012] According to another embodiment of a second aspect of the present invention is provided a method of inhibiting the release of pro-inflammatory substances from activated microglial cells comprising the administration to a human in need thereof a compound capable of inhibiting FLAP.
[0013] According to another embodiment of a second aspect of the present invention is provided a method of inhibiting the release of pro-inflammatory substances from activated microglial cells comprising the administration to a human in need thereof para-REV5901 (L-655,238), Bay-x-1005, ML-3000, NDGA or ZILEUTON®.
[0014] According to a first embodiment of a third aspect of the present invention is provided a method of treating Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, subarachnoid hemorrhage or other disorders associated with excessive production of inflammatory mediators in the brain comprising the administration to a human in need thereof a compound capable of inhibiting 5-LOX.
[0015] According to another embodiment of a third aspect of the present invention is provided a method of treating Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, subarachnoid hemorrhage or other disorders associated with excessive production of inflammatory mediators in the brain comprising the administration to a human in need thereof a compound capable of 5-LOX over COX-2.
[0016] According to another embodiment of a third aspect of the present invention is provided a method of treating Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, subarachnoid hemorrhage or other disorders associated with excessive production of inflammatory mediators in the brain comprising the administration to a human in need thereof a compound capable of inhibiting FLAP.
[0017] According to another embodiment of a third aspect of the present invention is provided a method of treating Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, subarachnoid hemorrhage or other disorders associated with excessive production of inflammatory mediators in the brain comprising the administration to a human in need thereof para-REV5901 (L-655,238), Bay-x-1005, ML-3000, NDGA or ZILEUTON®.
[0018] According to a first embodiment of a fourth aspect of the present invention is provided a method of attenuating degradation of IκBα comprising the administration to a human in need thereof a compound capable of inhibiting 5-LOX.
[0019] According to another embodiment of a fourth aspect of the present invention is provided a method of attenuating degradation of IκBα comprising the administration to a human in need thereof a compound capable of selectively inhibiting 5-LOX over COX-2.
[0020] According to another embodiment of a fourth aspect of the present invention is provided a method of attenuating degradation of IκBα comprising the administration to a human in need thereof a compound capable of inhibiting FLAP.
[0021] According to another embodiment of a fourth aspect of the present invention is provided a method of attenuating degradation of IκBα comprising the administration to a human in need thereof para-REV5901 (L-655,238), Bay-x-1005, ML-3000, NDGA or ZILEUTON®.
[0022] According to a first embodiment of a fifth aspect of the present invention is provided a method of inhibiting nuclear translocation of the NF-κB active complex comprising the administration to a human in need thereof a compound capable of inhibiting 5-LOX.
[0023] According to another embodiment of a fifth aspect of the present invention is provided a method of inhibiting nuclear translocation of the NF-κB active complex comprising the administration to a human in need thereof a compound capable of selectively inhibiting 5-LOX over COX-2.
[0024] According to another embodiment of a fifth aspect of the present invention is provided a method of inhibiting nuclear translocation of the NF-κB active complex comprising the administration to a human in need thereof a compound capable of inhibiting FLAP.
[0025] According to another embodiment of a fifth aspect of the present invention is provided a method of inhibiting nuclear translocation of the NF-κB active complex comprising the administration to a human in need thereof para-REV5901 (L-655,238), Bay-x-1005, ML-3000, NDGA or ZILEUTON®.
[0026] Other embodiments of the invention comprise two or more embodiments or elements thereof suitably combined.
[0027] Yet other embodiments and aspects of the invention will be apparent according to the description provided below.
DETAILED DESCRIPTION OF THE INVENTION
[0028] As used herein “a compound capable of selectively inhibiting 5-LOX over COX-2” means a compound having 1 to 500-fold or more, particularly 1 to 50-fold and more particularly 1 to 10-fold selectivity for 5-LOX over COX-2 as measured by the ability to attenuate the production of arachidonic acid metabolites from cellular suspensions (derived from blood or cell lines) stimulated with ionophore A23187 as previously described (Salari et al., 1984, Prostaglandins and Leukotrienes, Vol 13: 53-60; Menard et al., 1990, Br. J. Pharmacol 100: 15-20) incorporated by reference herein. For instance, 5-HETE and LTB4 are arachidonic acid metabolites derived from 5-LOX and 12-hydroxy-heptadecatrienoic (HHT) is an arachidonic acid metabolite for cycloxygenase activity. Alternatively, COX-2 can be specifically assessed by the ability to attenuate the production of the arachidonic acid metabolite, PGE2, from cellular suspensions (derived from blood or cell lines) stimulated with the LPS (Laufer et al., 1999, Inflammation Research, 48: 133-138; Horton et al., 1999; Anal Biochim 271:18-28).
[0029] As used herein “FLAP” means 5-LOX activating protein. Compounds that inhibit FLAP can be measured by the ability to inhibit photoaffinity labeling of a source of purified FLAP (i.e. rat or human). In addition, FLAP inhibitors are confirmed if there is a correlation in the inhibition of leukotriene synthesis in vitro cell based assays (i.e. Human PMN leukotriene synthesis) (Evans et al., 1991, Molecular Pharmacology 40:22-27).
[0030] As used herein “inflammatory mediators in the brain” includes but is not limited to cytokines, chemokines, prostaglandins and leukotrienes.
[0031] As used herein “pro-inflammatory substances” includes but is not limited to TNF-alpha, nitrite, NO, IL-6, IL-1, 5-HETE, LTB4, LTA4 and other inflammatory substances.
[0032] Bay-x-1005 (C 23 H 23 NO 3 ) is a selective inhibitor of FLAP. See Drugs Fut 1995, 20:996 and Drugs Fut 2000 25(10):1084.
[0033] ML-3000 is an inhibitor of both COX and LOX. See Drugs Fut 1995 20:1007 and Drugs Fut 25(10):1093.
[0034] REV5901-para-isomer (L-655,238-IC50=0.1uM-5-LOX) is a selective 5-lipoxygenase activating protein inhibitor (FLAP) with a quinoline structure. It has been reported that FLAP inhibitors with this basic chemical structure interfere with 5-LOX and FLAP protein interactions preventing a required cellular translocation of 5-LOX. Moreover, it has been shown that compounds with the quinoline chemical structure do not affect other routes of arachidonic acid metabolism including known cycloxygenase and other lipoxygenases proteins (Evans et al., 1991, Molecular Pharmacology 40:22-27; Hutchinson, A. W. 1991, Trend in Pharmacological Studies, 12: 68-70).
[0035] NDGA is a selective 5-lipoxygenese over cycloxgenase inhibitor ( IC50=0.2uM- 5-LOX, IC50=100 uM- COX)-Salari et al, 1984.
[0036] We have discovered that indirectly or directly inhibiting 5-lipoxygenase can preferentially attenuate pro-inflammatory cytokine release from activated rat microglia cells in comparison to COX-2 inhibition. While not intending to limit the scope of the invention to any particular mechanism the following description is provided. Cytosolic Ca2+dependent type IV phospholipase A2 (CPLA2) generates intracellular arachidonic acid (AA). AA is converted to pro-inflammatory prostaglandins, thromboxanes, and leukotrienes by either cycloxygenases (COX) or lipoxygenases (LOX).
[0037] Since cytosolic phospholipase A2 (cPLA 2 ) is one of the major enzymes involved in the generation of AA, the effect of lipopolysaccharide (LPS) on cPLA 2 was determined. Indirect immunofluorescence with a cPLA 2 specific monoclonal antibody revealed that cPLA 2 was localized primarily in the cytosol in untreated cells. Upon stimulation with LPS, cPLA 2 redistributed to form punctate bodies within 15 minutes and returned to a control immuno-staining pattern by 60 minutes (the transient redistribution of cPLA2 to punctate bodies is an intracellular event associated with higher activity). The activity of cPLA 2 can also be enhanced by phosphorylation (Lin et al., 1993). Phosphorylated cPLA 2 can be distinguished from unphosphorylated cPLA 2 by migration on SDS-PAGE. Immunoblotting revealed that cPLA 2 in control cells was predominately unphosphorylated. Following LPS challenge cPLA 2 shifted to a phosphorylated form between 10-20 minutes post-challenge. Importantly, CPLA2 inhibitors, i.e., ATFMK (arachidonyltrifluoromethyl ketone) and BMS 229724 have shown significant dose-dependent inhibition of TNF-alpha and nitrite release in LPS activated microglia. The redistribution and phosphorylation of cPLA 2 as well as, the attenuation of TNF-alpha and nitrite by cPLA2 inhibitors provide several lines of evidence for the activation of cPLA 2 in LPS treated microglia.
[0038] COX-2 inhibitors rofecoxib (VIOXX®) and celecoxib (CELEBREX®) had no significant effect on pro-inflammatory release on activated microglia. Importantly, para-REV5901 (α-pentyl-4-(3-quinolinylmethyl)benzenemethanol) a 5-LOX activating protein inhibitor and NDGA (nordihdroguaiaretic acid) a 5-LOX inhibitor, dose dependently inhibited TNF-alpha release and nitrite to near control levels following LPS challenge in microglia cells.
[0039] To further validate the role of 5-LOX in pro-inflammatory cytokine release transcriptional regulators of TNF-alpha and NO were examined. Lipoxygenases can activate NFκB mediated transcription via the generation of reactive oxygen intermediates (Lee et al., 1997; Bonizzi et al., 1999). Both the TNFα gene and inducible nitric oxide synthase (iNOS) gene contain NF-κB binding elements in their promoter sequences and activation of NF-κB is crucial for gene transcription (Goldfeld et al., 1990; Drouet et al., 1991; Xie et al., 1994). Hence the effects of inhibiting NF-κB mediated transcription using two distinct inhibitors was assessed with BAY 11-7085 an irreversible inhibitor of IκBα phosphorylation ([IC 50 -10 μM] a biochemical event associated NF-κB activity) and NF-κB SN-50 a cell permeable peptide which inhibits translocation of NF-κB active complex into the nucleus (a required intracellular event associated with NF-κB activity; Lin et al., 1995; Pierce et al., 1997). Both BAY 11-7085 and NF-κB SN-50 inhibited LPS induced TNFα and NO release to control levels.
[0040] To further characterize the involvement of NF-κB in microglial signaling, the effect of LPS on the degradation of IκBα and NF-κB (p65) translocation from the cytosol to the nucleus was also determined. It was observed that IκBα was rapidly degraded within 20 minutes following LPS activation and reappeared to control levels by 60 minutes. Consistent with these observations, indirect immunofluorecence with a p65 antibody indicated that in control cells p65 was primarily localized in the cytosol, but after stimulation with LPS p65 rapidly translocated to the nucleus. These results demonstrate that NF-κB mediated transcription can play a role in microglia activation.
[0041] To determine whether cPLA 2 and 5-LOX regulate TNFα and NO release by influencing NF-κB activation, the effects of cPLA 2 and 5-LOX inhibitors on IκBα degradation and nuclear translocation of NF-αB were examined. ATFMK and para-REV5901 attenuated the degradation of IκBα following LPS stimulation. ATFMK and para-REV5901 also delayed the translocation of NF-κB into the nucleus. These results demonstrate that both cPLA 2 and 5-LOX inhibitors attenuate the release of TNFα and NO by delaying IκBα degradation and interfering with NF-κB activation.
[0042] These data collectively represent that 5-LOX (via CPLA2, AA, and NF-κB signaling) is a preferential target over COX-2 in modulating or inhibiting microglia activation. Consequently, modulating either 5-LOX alone or in conjunction with COX-2 could have direct effects in enhancing neuronal survival in acute and chronic CNS diseases including Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, and subarachnoid hemorrhage.
[0043] Lin L L, Wartmann M, Lin A Y, Knopf J L, Seth A, Davis R J (1993) cPLA2 is phosphorylated and activated by MAP kinase. Cell 72:269-278.
[0044] Lee S, Felts K A, Parry G C, Armacost L M, Cobb R R (1997) Inhibition of 5-lipoxygenase blocks IL-1 beta-induced vascular adhesion molecule-1 gene expression in human endothelial cells. J Immunol 158:3401-3407.
[0045] Bonizzi G, Piette J, Schoonbroodt S, Greimers R, Havard L, Merville MP, Bours V (1999) Reactive oxygen intermediate-dependent NF-kappaB activation by interleukin-1beta requires 5-lipoxygenase or NADPH oxidase activity. Mol Cell Biol 19:1950-1960.
[0046] Goldfeld A E, Doyle C, Maniatis T (1990) Human tumor necrosis factor alpha gene regulation by virus and lipopolysaccharide. Proc Natl Acad Sci U S A 87:9769-9773.
[0047] Drouet C, Shakhov A N, Jongeneel C V (1991) Enhancers and transcription factors controlling the inducibility of the tumor necrosis factor-alpha promoter in primary macrophages. J Immunol 147:1694-1700.
[0048] Xie Q W, Kashiwabara Y, Nathan C (1994) Role of transcription factor NF-kappa B/Rel in induction of nitric oxide synthase. J Biol Chem 269:4705-4708.
[0049] Lin Y Z, Yao S Y, Veach R A, Torgerson T R, Hawiger J (1995) Inhibition of nuclear translocation of transcription factor NF-kappa B by a synthetic peptide containing a cell membrane-permeable motif and nuclear localization sequence. J Biol Chem 270:14255-14258.
[0050] Pierce J W, Schoenleber R, Jesmok G, Best J, Moore S A, Collins T, Gerritsen M E (1997) Novel inhibitors of cytokine-induced IkappaBalpha phosphorylation and endothelial cell adhesion molecule expression show anti-inflammatory effects in vivo. J Biol Chem 272:21096-21103.
[0051] Isolation of Microglia from Rat Brains:
[0052] Rat microglia were prepared from two day old rat pups. Pup brains were removed and the meninges were gently removed. Once sufficient amount of brains were collected, brains were minced with a blunt scissors (10 times) and transferred to a 15 ml conical tube with a pasteur pipette and titurated 25 times. Dissociated cells were then centrifuged at 1000 RPM for 10 minutes (RT). The supernatant was removed and 2 mls of fresh media was added. The resultant cell suspension was titurated 10 times. Following titration the cell suspension was plated in a T175 cm 2 culture flasks at a density of 4 brains per flask in 25 mls. MEM media was used for the experiments, supplemented with 10% FBS, 100 i.u.penicillin, 100 i.u.streptomycin and L-Glutamine. Microglia were isolated on day 14 by shaking on an orbital rotation shaker. The purity of the cultures was 98-100% as determined by immunostaining with ED-40 antibody.
[0053] Rat Microglia Cell Activation and Drug Exposure
[0054] Endotoxin (LPS) at a concentration of a 100 ng/ml were used for activation of rat microglia cells. This concentration had previously shown to be effective in inducing TNF-alpha and Nitrite release. All assays were performed in 48 well plates (Becton Dickinson) at ˜2×10 5 cells or 0.5×10 5 per 1 ml per well in 10% MEM media. Microglia cells were pre-incubated 1 hr prior to LPS challenge with either vehicle (0.1% DMSO) or test compound in DMEM containing 10% FBS (microglia) or RPMI containing 10% FBS (THP-1 monocytes). Supernatants from LPS activated rat microglia were collected at 24 hrs post-LPS challenge.
[0055] TNF-Alpha ELISA
[0056] Collected supernatants were assayed for TNF-alpha using a Pharmingen OPtEIA Rat (microglia).
[0057] Nitrite Assay
[0058] Nitrite assay was performed in a 96 well plate using a Modified Griess Reagent (Sigma). In brief, a 100 ul of Modified Griess Reagent was added to a 100 ul of collected supernatant. Samples were read at a wavelength of 540 nM. All values were calculated against a NaNO2 standard curve.
[0059] Immunofluorescence Cells were washed once with PBS, fixed and permeabilized with ice cold methanol (100%) for 5 minutes and washed 3× in PBS for 10 min. The cover slips were blocked for 1 hour in 10% serum/PBS (serum derived from animal in which secondary antibody was generated), incubated for 2-3 hours in primary antibody solution (1:50 dilution in 1.5% serum/PBS) and washed 3× in PBS for 10 min. Secondary antibody linked to fluorescein was applied for one hour (1:100 dilution in 1.5% serum/PBS) and washed 3× in PBS for 10 min. If the nucleus was stained, the cells were incubated for 15 minutes with DAPI (1:10000) at 37° C. and washed. The coverslips were then mounted onto glass slides using mounting media and viewed under a fluorescence microscope.
[0060] Immunoblotting
[0061] Immunoblotting was carried out as described previously (Parvathenani et al., 2000). Briefly 25 μg of protein was fractionated on a 4-20% tris-glycine gel (NOVEX, Calif.) and transferred to PVDF membrane (NOVEX, Calif.). The membrane was probed with a polyclonal antibody specific for IκBα. To distinguish between the phosphorylated and non-phosphorylated forms of cPLA 2 , 50 μg of protein was run on an 8% tris-glycine gel (Novex, Calif.) for 4.5 hours at 125V, transferred and probed with a monoclonal antibody specific for cPLA 2 .
[0062] Materials
[0063] NDGA (nordihdroguaiaretic acid), para-REV5901 (α-pentyl-4-(3-quinolinylmethyl)benzenemethanol), ATFMK (arachidonyltrifluoromethyl ketone) was obtained from Calbiochem (San Diego, Calif.). Ibuprofen and LPS was purchased from Sigma (St. Louis, Mo.). BMS 229724 was synthesized at Bristol-Myers Squibb. NF-κB SN50 and (E)3-((4-t-Butylphenyl)sulfonyl)-2-propenenitrile (BAY-11-7085) were obtained from Biomol (Plymouth Meeting, Pa.).
[0064] Figures:
[0065] The data represents mean ±S.D. of triplicate samples of an experiment repeated at least three times. *=Statistically significant (p<0.05) in comparison to LPS (positive control).
[0066] [0066]FIG. 1A-E Legend
[0067] Microglia were treated with 100 ng/ml of LPS for various periods of time following which A-D. cPLA 2 distribution was assessed by indirect immunofluorescence ( 1 A) control, ( 1 B) LPS-15 min, ( 1 C) LPS-15 min, ( 1 D) LPS-60 min, ( 1 E) whole cell lysates were prepared and run on SDS-PAGE, transferred and probed with a cPLA 2 antibody.
[0068] [0068]FIG. 2A-D Legend
[0069] 5-lipoxygnease inhibitor (NDGA, 2A) and 5-lipoxygenase activating protein inhibitor (para-REV5901, 2B) significantly inhibited TNF-alpha release, however, COX-2 inhibitors Ibuprofen ( 2 C), Vioxx ( 2 D), and Celebrex ( 2 D) failed to produce any reduction in TNF-alpha release in rat primary microglia cells following LPS activation.
[0070] [0070]FIG. 3A-B Legend
[0071] cPLA 2 inhibitors ATFMK ( 3 A) and BMS-229724 ( 3 B) significantly inhibited TNF-alpha release in rat primary microglia cells following LPS activation.
[0072] [0072]FIG. 4A-C Legend
[0073] cPLA 2 inhibitor, ATFMK ( 4 A) and FLAP inhibitor, para-REV5901 ( 4 B) significantly inhibited nitrite release in rat primary microglia cells following LPS activation. However, COX-2 inhibitor, Celebrex ( 4 C) had no effect on nitrite release.
[0074] [0074]FIG. 5A-B Legend
[0075] Effects of NF-κB inhibitors, BAY 11-7085 and SN-50 on TNFα and NO release in LPS treated microglia. Microglia were treated with various concentrations of either BAY-or SN-50 for one hour prior to the addition of LPS. Twenty-four hours post LPS challenge the media was assayed for TNFα release by ELISA ( 5 A) and nitrite release by modified Greiss reagent ( 5 B).
[0076] [0076]FIG. 6A-C Legend
[0077] Effects of cPLA 2 and 5-LOX inhibitors on LPS mediated IκBα degradation. Microglia were treated with 100 ng/ml of LPS for various periods of time following which whole cell lysates were prepared and run on SDS-PAGE, transferred and probed with a IκBα antibody as mentioned in immunoblotting. ( 6 A) 100 ng/ml LPS alone, ( 6 B) LPS+10 μM ATFMK, ( 6 C) LPS+50 μM L-655,238.
[0078] [0078]FIG. 7 A-D Legend
[0079] Effects of cPLA 2 and 5-LOX inhibitors on LPS mediated NF-κB translocation. Microglia were treated with 100 ng/ml of LPS for various periods of time following which p65 distribution was assessed by indirect immunofluorescence ( 7 A) control, ( 7 B) LPS-5 min., ( 7 C) LPS+10 μM ATFMK-5 min., ( 7 D) LPS+50 μM L-655,238 -5 min. ( 7 E) LPS+NDGA-20 μM -5 min. | The present invention provides methods of modulating or inhibiting microglia activation comprising the administration of a compound capable of inhibiting 5-LOX, FLAP, attenuating degradation of IκBα or inhibiting nuclear translocation of the NF-κB active complex for the treatment of Alzheimer's disease, brain ischemia, traumatic brain injury, Parkinson's Disease, Multiple Sclerosis, ALS, subarachnoid hemorrhage or other disorders associated with excessive production of inflammatory mediators in the brain. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of humidity control of a controlled space, and, in its most preferred embodiments, to the field of mist producing humidification systems for refrigerated environments.
The preservation benefits of refrigeration systems are very well known. However, it is also well known that refrigeration systems often extract moisture from the cooled air. As a result, refrigerated perishables, such as meats, fish, salads, flowers, and other products, often dry out and deteriorate in refrigerated display cases. In the past, various efforts have been made to increase humidity levels in refrigerated air. U.S. Pat. Nos. 2,281,458, 4,738,806, 2,531,506, and 2,097,530 disclose several systems claiming to increase humidity levels in refrigerated air.
Although increasing the amount of humidity in refrigerated air can often reduce dehydration of refrigerated perishables, too much humidity in closed cases is also problematic. Humidification systems which produce excessively humid air or, worse yet, spray moisture directly onto refrigerated perishables can cause certain refrigerated perishables to deteriorate more rapidly or become unsaleable.
Accordingly, it is recognized that systems which supply a very fine mist into the refrigerated air are preferable since very small droplets of water tend to evaporate quickly rather than settle and collect on the refrigerated perishables. Many previously developed humidifier systems which produce very fine mists are very complex in construction, operation, and maintenance. Furthermore, many of those systems lend themselves to contamination problems due to incorporation of standing water and various air atomization techniques.
There is, therefore, a need in the industry for a humidification system which solves these and other related, and unrelated, problems.
SUMMARY OF THE INVENTION
Briefly described, the present invention comprises a humidification system for humidifying a controlled space which, in its most preferred embodiment, includes a control device connected to a water source for supplying water at a constant pressure, a tubing network for transferring water from the control device, a mist nozzle located within the controlled space and connected to the tubing network to receive water transferred from the control device, and a droplet discrimination device positioned around the mist nozzle within the controlled space for removing and draining larger water droplets from the mist sprayed from the mist nozzle for releasing a very fine mist into the controlled space outside the droplet discrimination device.
It is therefore an object of the present invention to provide a humidification system for humidifying a controlled space through releasing a very fine mist into the controlled space.
Yet another object of the present invention is to provide a humidification system which is easy to install and maintain in both pre-existing and new refrigerated cases.
Still another object of the present invention is to provide a humidification system which is sanitary and free from contamination problems related to standing water and various air atomization techniques.
Still another object of the present invention is to provide a humidification system which introduces mist into a controlled space in such a form and at such a controlled rate that air within the space remains humid while moisture does not settle on perishables.
Still another object of the present invention is to provide a humidification system which includes a control device connected to a water supply, which control device includes a filter, a high pressure pump, a feedback regulator network for providing constant water pressure, and a timer for controlling misting cycles.
Still another object of the present invention is to provide a humidification system which includes a mist nozzle which emits a mist of separate droplets and a droplet discrimination device which sorts the droplets of the mist emitted from the mist nozzle to sort out and drain larger droplets to release a finer mist.
Still another object of the present invention is to provide a humidification system which includes a mist nozzle, which sprays a fine mist of disconnected water droplets having relatively low exit velocities, and a droplet discrimination device which are both removably located within the refrigerated space of a refrigerated case.
Still another object of the present invention is to provide a humidification system which includes a mist nozzle with a nozzle output orifice for emission of a mist and a droplet discrimination device which defines a mist chamber around the nozzle output orifice, the air in the mist chamber being circulated by mist movement alone.
Still another object of the present invention is to provide a humidification system which includes a mist nozzle with a nozzle output orifice and a droplet discrimination device which completely encloses the nozzle output orifice with the only exception of at least one release aperture located above the nozzle output orifice.
Still another object of the present invention is to provide a humidification system which includes a droplet discrimination device with a base for attachment to a case structure and receipt of a mist nozzle and a removable sleeve for collection of water droplets from the mist.
Still another object of the present invention is to provide a humidification system which includes a droplet discrimination device with a base for attachment to a case structure and receipt of a mist nozzle and a sleeve fixed to the base for collection of water droplets from the mist.
Still another object of the present invention is to provide a humidification system which includes a mist nozzle with an output orifice and a droplet discrimination device with a release aperture, wherein the mist nozzle is located within the droplet discrimination device and oriented to emit mist toward the release aperture.
Other objects, features and advantages of the present invention will become apparent upon reading and understanding this specification, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a refrigerated case equipped with a Humidification System With Droplet Discrimination, in accordance with a preferred embodiment of the present invention.
FIG. 2 is a schematic view of the humidification system shown in FIG. 1.
FIG. 2a is an electrical schematic of the control assembly shown in FIG. 2.
FIG. 3 is a side cross-sectional view of the misting assembly shown in FIG. 1.
FIG. 4 is a rear cross-sectional view of the misting assembly shown in FIG. 1.
FIG. 5 is a rear perspective view of the sleeve shown in FIG. 2.
FIG. 6 is a top plan view of the sleeve shown in FIG. 5.
FIG. 7 is a side cross-sectional side view of the sleeve shown in FIG. 6 taken along line 7--7.
FIG. 8 is a rear cross-sectional view of the sleeve shown in FIG. 6 taken along line 8--8.
FIG. 9 is a front perspective view of the base shown in FIG. 2.
FIG. 10 is a top plan view of the base shown in FIG. 9.
FIG. 11 is a side cross-sectional view of the base shown in FIG. 10 taken along line 11--11.
FIG. 12 is a front cross-sectional view of the base shown in FIG. 10 taken along line 12--12.
FIG. 13 is a schematic view of a humidification system in accordance with an alternate embodiment.
FIG. 14 is an exploded perspective view of the misting assembly shown in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in greater detail to the drawings, in which like numerals represent like components throughout the several views, the preferred embodiment of a refrigerated case 10 with a Humidification System 25 is shown in FIG. 1. The refrigerated case 10 includes a case base 16 supporting a display surface 12. The display surface 12 is located within a refrigerated space 15 which is enclosed by a glass hood 14 and sliding doors 20 which are supported by support posts 22. Air outlets 17 circulate cool air into the refrigerated space 15, and air intakes 18 remove air from the refrigerated space 15.
Enclosed within the case base 16 is a customary, forced-air refrigeration system (not shown) whose design and operation are considered well-known within the industry. One example of an acceptable refrigerated case 10 is the LCD model manufactured by Tyler Refrigeration Corporation of Niles, Mich. It should be understood that the particular refrigerated case 10 shown in FIG. 1 is shown by way of example only, and that alternately designed refrigerated cases 10 are included in alternate embodiments of the present invention. In one alternate embodiment, a gravity case is utilized which includes cooling coils supported in the upper portion of the refrigerated case 10, thus utilizing convection currents to circulate the cool air. Without limitation, other embodiments include display surfaces 12 which include grated platforms and draining formations for disposing of juices and other droppings from perishables displayed in the refrigerated case 10. In other alternate embodiments of the present invention, refrigerated cases 10 have refrigerated spaces which are not completely enclosed. Furthermore, other alternate embodiments include cases which are cooled with ice rather than refrigeration systems, and still others include cases which are heated, rather than cooled. In still other embodiments, the controlled spaces are neither heated nor cooled but simply need increases in humidity for various purposes.
In accordance with the preferred embodiment of the present invention, the humidification system 25 shown in FIG. 1 includes tap supply hose 27, control assembly 80 which is encased by a protective control box 81 and mounted inside the case base 16, supply main 29, supply tubes 32, mist assemblies 40 which emit fine mist 42, drain tubes 33, and drain main 30. In other alternate embodiments of the present invention, the control assembly 80 is mounted outside the refrigerated case 10. In the preferred embodiment, the tap supply hose 27 is connected to an ordinary utility water outlet. Through conventional tubing connectors and joints (not shown), supply main 29 splits off into several supply tubes 32 which extend into the refrigerated space 15 and are connected to the misting assemblies 40 which are located inside the refrigerated space 15 and mounted to the support posts 22. The drain tubes 33 are also connected to the misting assemblies 40 and extend outside the refrigerated case 10 to connect to the drain main 30 through conventional connectors (not shown). The drain main 30 connects to a standard drainage or sewage system. All of the humidification system tubing running through the refrigerated case 10 is positioned clear from the cold refrigeration elements to prevent freezing of water within the tubing.
It should be understood that the scope of the present invention includes variations in the number and locations of the misting assemblies 40 (and associated supply and drain tubes 32, 33) depending on the size and shape of the refrigerated case 10, as well as other environmental considerations including the types of perishables and placement of the refrigerated case 10. For example, in alternate embodiments, the misting assemblies 40 are mounted on the display surface 12 or angled in alternate directions. With respect to alternate embodiments including alternate cases, the misting assemblies 40 are mounted to various surfaces, including side walls and ceilings. In the preferred embodiment of the present invention, the misting assemblies 40 are vertically aligned, which, at least in part, addresses potential air back-flow concerns.
Refer now to the schematic representation of the humidification system 25 shown in FIG. 2. The control box 81 of the control assembly 80 is shown open to reveal the other elements of the control assembly 80 in accordance with the preferred embodiment of the present invention. Tap supply hose 27 is connected to an intake valve assembly 83 which is connected to the control box 81. Connected down-line from the intake valve assembly 83 and located inside the control box 81 is a filter 85. Pre-pump tubing 86 connects the filter 85 to a high pressure pump 89, a supply indicator 87, and a feedback line 92. Post-pump tubing 88 connects the pump 89 to a pressure gauge 94, a pressure regulator 91 which is connected to the feedback line 92, and a control solenoid 95. A supply coupling assembly 93 is connected to the control box 81 and connects the control solenoid 95 to the supply main 29. A timer 96 is also shown mounted within the control box 81.
Referring now to FIG. 2a, an electrical schematic of the control assembly 80 in accordance with the preferred embodiment of the present invention, an AC plug 102 is shown connected to a transformer 101 which, in the preferred embodiment of the present invention, transforms 110 VAC to 24 VAC. An on-off switch 100 is located between the transformer 101 and the timer 96. The supply indicator 87 is shown connecting the timer 96 to both the high pressure pump 89 and the control solenoid 95. Operation of the control assembly 80 is discussed in detail below.
Referring back to FIG. 2, in the preferred embodiment of the present invention, the misting assemblies 40 are identical; therefore, although the following description is given in terms of a single misting assembly 40, the description should be understood to apply to each of the misting assemblies 40. In accordance with the preferred embodiment of the present invention, the misting assembly 40 includes a discriminator 48 and a nozzle 58. In the preferred embodiment, the discriminator 48 includes a base 65 and a sleeve 50. The base 65 includes a mounting plate 67 which is removably secured to a support post 22 (shown in FIG. 1). The sleeve 50 includes a sleeve front 51 and a sleeve rear 52 and is removably connected to the base 65 so that the sleeve rear 52 is adjacent the support post 22. The sleeve 50 also includes collection surfaces 53 and a lip 55 which includes a lip bottom 56. The fine mist 42 is seen passing through a release aperture 57.
Referring now to FIGS. 3 and 4, which are side and rear cross-sectional views, respectively, of the misting assembly 40 in accordance with the preferred embodiment of the present invention, the misting assembly 40 is shown to further include a nozzle coupling 73 and a drain coupling 75. The base 65 includes a support platform 70 to which the couplings 73, 75 are attached and upon which the sleeve 50 rests. The tubes 32, 33 are also seen connected to the couplings 73, 75, respectively. The nozzle 58 includes a nozzle orifice 59 and a nozzle base 60 which is connected to the nozzle coupling 73. The sleeve 50 is also seen defining a mist chamber 54.
FIGS. 5 and 6 show rear perspective and top plan views, respectively, of the sleeve 50 in accordance with the preferred embodiment of the present invention. The sleeve front 51 and sleeve rear 52 are shown along with the lip 55, lip bottom 56, and collection surfaces 53 which border the mist chamber 54. FIG. 7 is a side cross-sectional view of the sleeve 50 taken along line 7--7 of FIG. 6. Lip angle "e" is shown representing the angle made by the lip 55 with the horizontal top of the sleeve 50, and lip length "d" represents the length of lip 55. The height of the mist chamber 54, also indicated as the height of the collection surfaces 53, is represented by dimension "b", and the depth of the mist chamber 54 is represented by dimension "a". FIG. 8 is a rear cross-sectional view of the sleeve 50 taken along line 8--8 of FIG. 6. Dimension "c" represents the width of the mist chamber 54.
FIGS. 9 and 10 show front perspective and top plan views, respectively, of the base 65 in accordance with the preferred embodiment of the present invention. The mounting plate 67 is shown including two mounting passages 68 through which screws are placed to secure the base 65 to the support post 22 (shown in FIG. 1). The base 65 is also shown defining a sleeve port 69 for receipt of the sleeve 50 (shown in FIG. 5). A nozzle passage 72 and a drain passage 74 are also seen extending through the support platform 70 for receipt of the nozzle and drain couplings 73, 75, respectively (shown in FIG. 3). FIG. 11 is a side cross-sectional view of the base 65 taken along line 11--11 of FIG. 10. An access passageway 76 is shown extending below the mounting plate 67 from under the support platform 70. In one alternate embodiment of the present invention, the supply and drain tubes 32, 33 are routed through the support post 22 (shown in FIG. 1) and through the access passageway 76. FIG. 12 is a front cross-sectional view of the base 65 taken along line 12--12 of FIG. 10. The nozzle passage 72 is seen extending through the support platform 70 which defines the bottom of the sleeve port 69.
OPERATION
Referring back to FIGS. 1, 2, and 2a, water is supplied to the humidification system 25 of the preferred embodiment of the present invention through tap supply hose 27. When the intake valve assembly 83 is closed, water flow is stopped, allowing maintenance or repair on the elements inside the control box 81, such as cleaning the filter 85. When the intake valve assembly 83 is open, water flows through the filter 85 which contains a screen to remove dirt and particulates from the water which could potentially interfere with the operation of other elements of the humidification system 25. One example of an acceptable filter 85 is a conventional 450 mesh screen filter.
In the preferred embodiment of the present invention, the pre-pump tubing 86 supplies water from the filter 85 to the high pressure pump 89 and the supply indicator 87. The supply indicator 87 continually evaluates whether water is being supplied to the high pressure pump 89 by monitoring the water pressure in the pre-pump tubing 86. It is understood that operation of the high pressure pump 89 without a supply of water in the pre-pump tubing 86 may cause damage to the high pressure pump 89. As is shown in FIG. 2a, the supply indicator 87 acts as a switch to allow or prevent electrical current flow to the high pressure pump 89 and the control solenoid 95. In the preferred embodiment of the present invention, the supply indicator 87 includes a polyurethane (polyether) diaphragm and has a mechanical contact rating of at least 4 amps for voltages as high as 250 VAC, a proof pressure of 125 psi (pounds per square inch), and a burst pressure of 160 psi. In the preferred embodiment, when water pressure falls below 5 psi, the supply indicator 87 of the preferred embodiment prevents current from flowing to the high pressure pump 89 and the control solenoid 95, thus disabling the high pressure pump 89 and closing the control solenoid 95.
In the preferred embodiment of the present invention, the high pressure pump 89 supplies water to the post-pump tubing 88 at an increased pressure ranging between 130 psi and 250 psi. One example of an acceptable high pressure pump 89 is a pump that will deliver at least 4 gallons per hour at a pressure between 150 psi and 180 psi, operate at 24 volts, and require approximately 5 amps. Other alternate embodiments of the present invention include pumps supplying higher or lower pressures.
The pressure gauge 94 continually measures and indicates the water pressure in the post-pump tubing 88 to enable a human operator to monitor the water pressure. According to the preferred embodiment of the present invention, the pressure regulator 91 and the feedback line 92 operate as a feedback regulator network which attempts to maintain the water pressure in the post-pump tubing 88 at a pre-selected pressure, regardless of the number of misting assemblies 40 contained in the humidification system 25. In this way, one or more misting assemblies 40 may be added to or removed from the humidification system 25 while not affecting the water pressure to each of the misting assemblies 40. Since the amount of water pressure affects the quality of mist emitted from the mist nozzles 58, the pressure regulator 91 and the feedback line 92 help to ensure optimum mist quality.
In the preferred embodiment of the present invention, the pressure regulator 91, often referred to in the industry as a back pressure valve, is designed to, on a continuous or intermittent basis, limit the desired maximum pressure by releasing water into a lower pressure line or area. Back pressure valves, when properly sized, open and close at predetermined points to provide accurate, functional control for continuous protection of pumps and delivery of desired pressures. In the preferred embodiment of the present invention, the pressure regulator 91 is capable of controlling pressures at flow rates as low as 0.4 gallons per hour and as high as 6 gallons per hour at 150 psi.
The control solenoid 95 is a normally closed, electrically-controlled valve which is either open in both directions or closed in both directions. One example of an acceptable control solenoid 95 is a direct acting, 24 VAC valve which operates effectively with water pressures ranging up to 200 psi. Among other functions, the control solenoid 95 selectively prevents water from continuously flowing through the control assembly 80 since, in the preferred embodiment, water would otherwise flow through the high pressure pump 89 due to water pressure from the utility outlet.
In addition to being controlled by supply indicator 87, operation of both the control solenoid 95 and the high pressure pump 89 is controlled by the timer 96. The timer 96 is selectively programmable to a variety of on/off cycle combinations. One example of an acceptable timer 96 is a repeat cycle timer having a relay output rated at 10 amps, a dual input voltage capability (110 VAC or 24 VAC), a multi-timing range of 0.1 second to 10 hours, an "on" dial for setting the amount of "on" time, and an "off" dial for setting the amount of "off" time.
In the preferred embodiment of the present invention, the timer 96 is programmed to both open the control solenoid 95 and operate the high pressure pump 89 for a period of 0.7 seconds to cause water to be pumped at a high pressure through the supply coupling assembly 93 and the supply main 29. This "on" period is followed by an "off" period of 2 seconds when the control solenoid 95 is closed and the high pressure pump 89 is inactive. The timer 96 alternates between these "on" and "off" periods continuously. It should be understood that these "on" and "off" times are selectively variable, depending, at least in part, on the type of product and amount of air being humidified.
As highly pressurized water is supplied to the supply main 29, the water is transferred from the control assembly 80 on a path through both the supply main 29 and the supply tubes 32 to the misting assemblies 40. In the preferred embodiment of the present invention, the high pressure pump 89 also functions as a check valve to prevent water from flowing in the reverse direction from the post-pump tubing 88 to the pre-pump tubing 86. Therefore, when the control solenoid 95 is closed, the water pressure within the post-pump tubing 88 remains relatively constant. However, immediately after the control solenoid 95 is closed, the water pressure in the supply main 29 and the supply tubes 32 begins to fall off since the misting assemblies 40 remain open. When the timer 96 again opens the control solenoid 95, the water pressure in the supply main 29 and the supply tubes 32 is returned to the optimum pressure during the initial portion of the "on" cycle. The amount of water pressure lost during the "off" cycle depends, at least in part, on the length of the "off" cycle and the number of misting assemblies 40.
Referring also to FIGS. 3 and 4, as the pressurized water reaches the misting assembly 40 through the supply tube 32, the water travels through the nozzle coupling 73 and into the nozzle base 60 of the mist nozzle 58. The water travels through the mist nozzle 58 and is sprayed from the nozzle orifice 59 into the mist chamber 54 as nozzle mist 43, a mist of separate and independent water droplets travelling in a nozzle-specific spray pattern. In the preferred embodiment of the present invention, water droplets of the nozzle mist 43 vary in size from approximately 5 microns to over 60 microns. One example of an acceptable mist nozzle 58 sprays mist in a 45-degree conical spray pattern at a rate of 0.4 gallons per hour when receiving water at a pressure of 150 psi. It is understood that the pressure of the water supplied to the mist nozzle 58 affects the size of the water droplets of the nozzle mist 43, thus the water pressure is preferably maintained within an optimum range during the "on" period to induce emission of the finest possible nozzle mist 43. This optimum range of pressure for the preferred mist nozzle 58 includes pressures greater than 120 psi.
As the water droplets in the nozzle mist 43 travel away from the nozzle orifice 59, the size, weight, and initial direction of travel of each water droplet determines, at least in part, the droplet's destiny. In the preferred embodiment of the present invention, most of the larger water droplets tend to come into contact with the collector surfaces 53 or the lip bottom 56 of the sleeve 50. Upon making contact, the larger water droplets adhere to the collector surfaces 53 or the lip bottom 56, or are otherwise impeded from upward movement, whereas the lighter water droplets tend to float upward and outward through the release aperture 57 of the sleeve 50 to be released as the fine mist 42. The fine mist 42 is composed of water droplets which are sufficiently small, typically ranging between 1 and 20 microns in the preferred embodiment of the present invention, to evaporate before contacting perishables contained within the refrigerated case 10. It is a goal of the preferred embodiment of the present invention to coordinate, without limitation, droplet size, droplet speed, droplet weight, droplet initial direction of travel, shape and size of discriminator 48, and location and orientation of mist nozzle 58 to minimize the possibility that larger droplets will exit the release aperture 57 as part of the fine mist 42.
As the larger water droplets continue to collect on the collector surfaces 53 of the sleeve 50, they begin to accumulate and drain downward toward the support platform 70 of the base 65. The draining water then passes through the drain coupling 75, the drain tube 33, and the drain main 30 to a point outside the refrigerated case 10.
In addition to the size, speed, emission rate, and initial direction of travel of the water droplets emitted from the mist nozzle 58, all of which are determined, in part, by the water pressure and type of mist nozzle 58, the shape and dimensions of the discriminator 48 of the preferred embodiment of the present invention affect the fine mist 42 which is released into the refrigerated space 15 and provide control over the distribution of moisture into the refrigerated space 15. In the present invention, the discriminator 48 is so constructed that air within the mist chamber 54 moves primarily in response to movement of the nozzle mist 43 as it exits the mist nozzle 58. The depth "a", height "b", and width "c" of the mist chamber 54, as well as the lip length "d" and lip angle "e" (shown in FIGS. 7 and 8), all affect the amount and average droplet size of the fine mist 42. The lip length "d" and lip angle "e" also affect the direction taken by the fine mist 42 as it exits the release aperture 57. Examples of acceptable dimensions of an acceptable discriminator 48, which dimensions correspond to the above-disclosed acceptable examples of other elements, are as follows: depth "a"=1 inch; height "b"=6 inches; width "c"=2 inches; lip length "d"=1 inch; and lip angle "e"=60 degrees.
The position and orientation of the mist nozzle 58 also affect various qualities of the mist released from the misting assembly 40. In the preferred embodiment of the present invention, the mist nozzle 58 is located below the release aperture 57 at the bottom of the mist chamber 54 and is oriented so that the nozzle orifice 59 faces the release aperture 57. As the nozzle mist 43 is emitted from the nozzle orifice 59, the initial directions taken by the droplets of the nozzle mist 43 aid in the migration of the smaller droplets which eventually form the fine mist 42. In other words, in the preferred embodiment of the present invention, the initial direction taken by each of the droplets of the nozzle mist 43 includes a vector component of direction toward the release aperture 57.
The construction of the misting assembly 40 also accommodates maintenance concerns. In the preferred embodiment of the present invention, the discriminator 48 is composed of stainless steel and is easily disassembled and removed from the refrigerated case 10 for ease of cleaning.
ALTERNATE EMBODIMENTS
It is intended that the scope of the present invention include various alternate embodiments. However, it should also be understood that the each of the embodiments disclosed herein, including the preferred embodiment, includes features and characteristics which are considered independently inventive. Accordingly, the disclosure of variations and alterations expressed in alternate embodiments is intended only to reflect on the breadth of the scope of the present invention without rendering obvious or unimportant any of the specific features and characteristics of the preferred embodiment.
A first alternate embodiment of the present invention is represented by FIGS. 13 and 14. FIG. 13 is a schematic view of a humidification system 25' in accordance with an alternate embodiment of the present invention, and FIG. 14 is an exploded perspective view of the misting assembly 40' shown in FIG. 13. An alternate control assembly 81' includes a high pressure water tank 98 with a tank pressure sensor 99. In addition, the control solenoid 95 is located down-line from both the supply coupling assembly 93 and the high pressure water tank 98.
The alternate control assembly 81' operates similarly to the preferred embodiment in many respects. However, operation of the high pressure pump 89 is controlled, at least in part, by the tank pressure sensor 99. When water pressure in the high pressure water tank 98 decreases below a predetermined level, the high pressure pump 89 is activated to increase the water pressure. Use of the high pressure water tank 98 provides the present invention with a means for more rapidly returning the water pressure in the supply main 29 and supply tubes 32 to optimum levels during the initial portion of each "on" period, discussed in more detail above. Consequently, water is supplied to the misting assemblies 40' at optimum pressures for a greater percentage of each "on" period. In another alternate embodiment of the present invention, (not shown) a control solenoid 95 is located at each misting assembly 40' to replace the single control solenoid 95 located at the high pressure water tank 98. In such an embodiment, water is supplied to the misting assemblies 40' at optimum pressures for an even greater percentage of each "on" period.
The alternately shaped misting assemblies 40' are another variation from the preferred embodiment of the present invention. FIG. 14 shows that the misting assembly 40' includes a right circular cylindrical discriminator 48'. A cylindrical sleeve 50' is connected to a cylindrical base 65' and a sleeve cap 49 which includes a cap director 56 and defines a circular release aperture 57' and a cylindrical mist chamber 54'. As with the preferred embodiment of the present invention, the mist nozzle 58 is connected to the nozzle coupling 73 which is connected to the base 65' along with the drain coupling 75. The cap director 46, like the lip 55 of the preferred embodiment shown in FIG. 2, aids in collecting larger water droplets and selectively directing the fine mist 42 released through the release aperture 57'.
The present invention is also considered to include other alternately shaped discriminators 48'. In other alternate embodiments of the present invention, discriminators 48' define unitary structures of various compositions, define mist chambers 54' of various shapes and sizes, include one or more alternately shaped release apertures 57', and include alternate draining paths. Alternately shaped discriminators include discriminators having various cross-sectional shapes such as triangles, squares, hexagons, pentagons, hexagons, ovals, etc. Furthermore, other discriminators 48' include adjustable release apertures 57' and mist directing devices such as the lip 55 and the cap director 46.
Although the scope of the present invention is understood to include many variously shaped discriminators in alternate embodiments, the inventiveness of various features of the discriminator 48 of the preferred embodiment is not limited by inclusion of such alternate embodiments. Without limitation, several of these features include selection of specific dimensional features such as the length "b" of the discriminator 48, the enclosing, "wrap-around" shape of the discriminator 48, and the location and orientation of the mist nozzle 58 with respect to the release aperture 57.
It should also be understood that other mist nozzles 58 included within the scope of the present invention require alternate amounts of water pressure to emit the finest mist available from the alternate mist nozzles 58, thus it should be understood that alternate high pressure pumps 89 or pressure regulators 91 should accordingly be substituted, or appropriate adjustments should be made to the preferred pressure regulator 91, to accommodate alternate mist nozzles 58.
It should also be understood that the each of the variations from the preferred embodiment of the present invention discussed in relation to the alternate embodiments of the present invention are separate and distinct. All combination of the variations are considered to be within the scope of the present invention.
While the embodiments of the present invention which have been disclosed herein are the preferred forms, other embodiments of the apparatus of the present invention will suggest themselves to persons skilled in the art in view of this disclosure. Therefore, it will be understood that variations and modifications can be effected within the spirit and scope of the invention and that the scope of the present invention should only be limited by the claims below. It is also understood that any relative dimensions and relationships shown on the drawings are given as the preferred relative dimensions and relationships, but the scope of the invention is not to be limited thereby. | A humidification system for humidifying a controlled space which, in its most preferred embodiment, includes a control device connected to a water source for supplying water at a constant pressure, a tubing network for transferring water from the control device, a mist nozzle located within the controlled space and connected to the tubing network to receive water transferred from the control device, and a droplet discrimination device positioned around the mist nozzle and located within the controlled space for removing and draining larger water droplets from the mist sprayed from the mist nozzle for releasing a very fine water mist into the controlled space outside the droplet discrimination device. | 0 |
FIELD OF THE INVENTION
The present invention relates in general to internal combustion engine carburetion systems, and in particular, to an improved post carburetion method and apparatus for creating a closer union of hydrocarbon and air molecules in fuel sources used within an engine.
BACKGROUND OF THE INVENTION
Without limiting the scope of the invention, its background is described in connection with engine carburetors for two and four intake manifolds, as an example.
Internal combustion engines rely upon distinct principles of operation to effectuate their intended purpose. One, a fuel/air mixture must be delivered to a combustion chamber. Two, that mixture must be compressed, prior to ignition. Three, once ignited, a means must be provided to displace the power released by the “exploded” mixture. And fourth, provision must be made to eliminate all residue gases in the combustion chamber, prior to introducing a fresh fuel/air mixture to the compression cylinder. The present invention speaks to the production of a volatile mixture of fuel and air, prior to the delivery of that mixture to the engine's combustion chamber.
As used in conjunction with standard carburetion processes, today's internal combustion engines suffer a loss of efficiency varying between 27% and 45%. Such loss of efficiency is directly attributable to the quantity of hydrocarbon and air molecules remaining unburned during the engine's power, or combustion phase. Given this inefficiency, it is clearly desirable to improve upon present day internal combustion engine fuel/air mixture processes, and apparatuses.
A number of attempts have been made to improve the homogeneity of fuel and air mixtures being supplied to an internal combustion engine. Such undertakings often rely upon exhaust gas, “coolant” or other engine derived heat source, to heat some or all of the fuel, air, or fuel and air mixture to promote enhanced mixing. Enhanced mixing, in turn, provides for improved dispersion of fuel throughout the air volume. Devices and techniques for improving gas mileage, operating performance and internal combustion engine efficiency are numerous, known and evidenced in the prior art.
By way of example, U.S. Pat. No. 3,968,781 discloses a fuel atomizing device for carburetors of internal combustion engines. U.S. Pat. No. 4,063,541 discloses a carburetor providing a uniformly atomized fuel mixture. U.S. Pat. No. 4,162,281 discloses a carburetor fuel atomization apparatus. U.S. Pat. No. 5,000,152 discloses a fuel conservation means for internal combustion engines. U.S. Pat. No. 5,053,170 discloses a fuel atomizing device for carburetors. U.S. Pat. No. 4,230,081 discloses a system for improving internal combustion engine efficiency. U.S. Pat. No. 4,345,570 discloses a fuel heating apparatus for vehicles. U.S. Pat. No. 5,437,258 discloses a carburetor fuel atomizer. U.S. Pat. No. 4,594,991 discloses a fuel and water vaporizer for internal combustion engines. Lastly, U.S. Pat. Nos. 4,167,165, 4,498,447 and 4,364,365 all purport to disclose fuel vaporizers for internal combustion engines.
SUMMARY OF THE INVENTION
It has been found, however, that the present methods and intake manifolds for internal combustion engines based on gasoline, fail to improve on the 27 to 45 percent inefficiency in combustion. This inefficiency in combustion leads to the increases in environmental contamination from already inefficient engines. Also, present carburetors have an added problem of having a need for frequent tuning.
What is needed is a method, apparatus and system that improves engine fuel efficiency. Also needed is an apparatus and method for decreasing the environmental contamination caused by the internal combustion without decreasing the power output of the engine.
The present invention differs substantially from the conventional concepts and designs of the prior art when providing a closer union of hydrocarbon and air molecules in fuel sources used in internal combustion engines, without increasing the temperature of the mixture. It has been found that the present invention improves upon the efficiency of an engine's internal combustion process and allows for a reduction in fuel consumption by generating a micromist caused by micromixing fuel and air. By decreasing the size of the fuel droplet using a combination of air turbulence and changes in pressure the present invention causes the formation of a fine mist without the need to increase the temperature of the fuel/air mixture and without decreasing the power output of the engine.
In fact, the present inventor has found that the present invention increases fuel efficiency, power and engine life, while concurrently decreasing environmental contamination. Recognizing the significance of increase in engine operating efficiency, it can be readily appreciated that there exists a continuing, real need for an improved internal combustion engine fuel/air mixing and integration method and apparatus. Finally, the present invention has no moving parts that can wear and does not require electrical or other motive force inputs.
The present invention provides for increased durability, improved performance, and structural integrity over existing mixing methods and apparatuses. Indeed, the present invention has been found to increase both the power and life of an internal combustion engine. Several unique improvements over the prior art are presented by the present invention. The invention is absent any moving parts. Also, the invention does not require any electrical connections or motors to initiate or perform its mixing process. Finally, the invention is easy to install in pre-existing engines without the need to drill into existing parts and does not adversely affect engine performance or tuning. In fact, the present invention has been found to lengthen the time between tunings.
A primary object of the present invention is to insight, or further micromist or micromix, molecules of hydrocarbon and air causing a closer union of the two molecules for more efficient combustion. The present invention reduces the velocity and rotation of the turbulence of a fuel and air mixture as it passes through the invention from an internal combustion engine's carburetor into the combustion chamber. Furthermore, the present invention reduces environmental contamination through a more efficient combustion process achieved through the superior mixing and more complete integration of hydrocarbon and air molecules.
More particularly, the present invention is a micromixing apparatus for creating a closer union of fuel and air molecules, in combination with an internal combustion engine and fuel supply, the apparatus includes a variable width cylinder designed to fit within a housing, the interior and exterior of the cylinder defining at least two paths and a variable width interior core positioned within the variable width cylinder, whereby fuel and air molecules that travel along the length of the variable width cylinder and interior core change in speed and volume as they travel through the at least two paths defined by the cylinder and the interior core. The variable width cylinder may also include a diffusing crown integrated as part of the exterior of the cylinder.
The variable width interior core may also include at least one pressure differentiation protrusion that extends into at least one of the paths. The variable width cylinder may also include at least one path exchange orifice that permits the fuel and air mixtures traveling along theat least two paths to mix. A cone may be located at the end of the cylinder and even the interior core to cause an expansion of the fuel air mixture.
In another embodiment of the invention a misting or micromixing apparatus housing having two or more openings may also include at least one variable width cylinder located within each of the misting or micromixing apparatus housing, at least one bolting mechanism positioning guide integrated within the misting or micromixing apparatus housing and at least one bolting mechanism connecting the misting or micromixing apparatus housing to an engine intake manifold. An intake manifold adapter may also be attached to the misting or micromixing apparatus housing, as well as carburetor adapter. The housing may also include at least one warm air induction input.
The present invention also includes a method for creating a closer union of hydrocarbon and air molecules for use in combination with an internal combustion engine and fuel supply, the method including the steps of, directing fuel and air molecules into at least two paths, whereby the length and volume defined by the first and second paths varies along the length of the at least two paths and causes an expansion and contraction of the hydrocarbon and air molecules as they travel the length of the paths. The method may also include the step of mixing the fuel and air molecules mixtures in the first and second paths through at least one opening that communicates between the paths, whereby the mixture from the paths combine. One may also provide one or more escape cones at the end of the first and second paths whereby the one or more cones cause a final expansion of the mixture before entering the combustion chamber of an engine. The mixing of the fuel air mixture may be accomplished by facilitating transport of the fuel and air molecules laterally and bi-directionally between the at least two paths. Also, the method may include reducing the rotation of the fuel and air mixture by positioning at least one diffusion crown in at least one of the paths.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
FIG. 1 is a perspective view of one form of the invention illustrated in combination with an internal combustion engine;
FIG. 2 is a perspective view of one form of the invention illustrated in combination with an internal combustion engine intake manifold and carburetor;
FIG. 3 is a part diagram, part cross-sectional illustration showing an external view of the invention's misting or micromixing cone seated within the invention's concentric cylinder;
FIG. 4 is a cross sectional view of the invention's concentric cylinders further illustrating an alternative embodiment of the present invention;
FIG. 5 is a top view of one form of the invention's warm air induction means;
FIG. 6 is a perspective view of one form of the invention illustrating the invention's interior core and concentric cylinder;
FIG. 7 illustrates a side view of an alternative embodiment of the invention's misting or micromixing cone; and
FIG. 8 shows a cross-sectional view of an alternative embodiment of the invention's interior core.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.
Turning now to FIG. 1 . FIG. 1 shows the invention's misting or micromixing apparatus housing ( 1 ) interposed between an internal combustion engine's carburetor ( 2 ) and an internal combustion engine's intake manifold ( 3 ) and illustrates the positioning of the invention, most particularly, the invention's misting or micromixing apparatus housing ( 1 ) as it is to be configured in typical internal combustion engine applications. FIG. 1 further illustrates one position, though not necessary, for the invention's warm air induction means flexible tubing ( 39 ).
Referring now to FIG. 2 . As can be seen from FIG. 2, the invention's misting or micromixing apparatus housing ( 1 ) is positioned with respect to an internal combustion engine's carburetor ( 2 ) and the engine's intake manifold ( 3 ) by using an intake manifold adapter ( 6 ) and a carburetor adapter ( 8 ). A bolting mechanism positioning guide ( 17 ) allows for a bolting mechanism ( 16 ) to position, and connect the engine's carburetor ( 2 ), carburetor adapter ( 8 ), misting or micromixing apparatus housing ( 1 ), intake manifold adapter ( 6 ), and the intake manifold ( 3 ). Also illustrated in FIG. 2, and as will be discussed in appropriate sections of this disclosure, are the invention's warm air induction means flexible tubing ( 39 ), the invention's misting or micromixing concentric cylinder ( 12 ) and the invention's diffusing crown ( 14 ).
Turning now to FIG. 3 a partial cross-sectional view of the present invention is depicted. The present invention facilitates its purpose of creating a closer union of fuel and air molecules via post carburetion processing. Such processing entails repeatedly integrating the fuel and air molecules via the invention's pressure and flow-rate variation process and apparatus, and more specifically, speaks to the repeated integration and exchange of the fuel and air molecules between the invention's misting or micromixing unit's interior core cylinder ( 37 ), and the misting or micromixing concentric cylinder ( 12 ). The invention's misting or micromixing concentric cylinder ( 12 ) is presented as a function and form within the misting or micromixing apparatus housing ( 1 ) and is not to be deemed limited to a specific carburetor/intake manifold configuration. The invention provides for, and supports, any configuration of carburetor and intake manifold design requirements (i.e. single, dual, or multiple barrel carburetors, and single or multiple intake manifold ports).
Subsequent to the standardized carburetion process, an initial fuel/air mixture is introduced paths formed by the invention's misting or micromixing concentric cylinder ( 12 ) and interior core cylinder ( 37 ). The fuel and air mixture is introduced into the interior core cylinder ( 37 ) via the interior core micromixing inlet ( 34 ). Fuel introduced to the invention's misting or micromixing concentric cylinder ( 12 ) is forced downward, and across a diffusing crown ( 14 ) located in this embodiment between the cylinder ( 12 ) and the housing ( 1 ).
The purpose of the invention's diffusing crown ( 14 ) is to reduce both the lateral velocity and the turbulence of the fuel air mixture that is caused during standardized carburetion, as well as provide for variations in pressure and flow rate within a fuel stream entering the mixing paths. Proceeding downward through the misting or micromixing concentric cylinder ( 12 ), increased pressure is placed upon the fuel/air mixture as the circumference of the cylinder is reduced. The increased pressure acts upon the introduced fuel/air mixture in the misting or micromixing concentric cylinder ( 12 ) and induces a transfer of the fuel/air mixture from the misting or micromixing concentric cylinder ( 12 ) to the invention's internal core cylinder ( 37 ) through the invention's chamber exchange openings ( 28 ).
The invention may also include one or more exchanges between the misting or micromixing concentric cylinder ( 12 ) to internal core cylinder ( 37 ) based upon the severity of reduction in the misting or micromixing concentric cylinder ( 12 ) circumference reduction and the availability and number of chamber exchange orifices ( 28 ). The invention's external cone body ( 11 ) may be seated flush against the concentric cylinder walls ( 13 ), causing passage of any fuel/air throughout that cylinder to be facilitated by one, or any number of suppressed channels ( 26 ) formed between flanges ( 29 ) located along the misting or micromixing concentric cylinder's ( 12 ) exterior cone body ( 11 ). The external cone body ( 11 ) may be pressure-fitted into the housing ( 1 ) or may even be welded into the housing ( 1 ).
In operation, the interior core components ( 36 ) and processes associated therewith are next discussed and explained. A fuel/air mixture having been produced in association with a standardized carburetion process enters the internal portion of the concentric cylinder ( 12 ) by way of the interior core micromixing inlet ( 34 ) and past the exterior and interior of the misting or micromixing unit interior core ( 36 ).
One or more pressure differentiation protrusions ( 35 a, b, c ) are integrated as part of the invention's interior core ( 36 ). The differentiation protrusions ( 35 a, b, c ) cause a change in fuel/air velocity and pressure such that the speed of the fuel/air mixture in the interior core cylinder ( 37 ) and concentric cylinder ( 12 ) vary with respect to one another. Consequently, an exchange of fuel/air mixture from the interior core cylinder ( 37 ) to the concentric cylinder ( 12 ), via the invention's chamber exchange opening ( 28 ) is initiated.
The changes in fuel/air mixture pressure and velocity caused by both the internal protrusions ( 35 a, b, c ) and the diffusion crowns ( 14 , 29 ) force the fuel and air molecules to form a fine mist that brings smaller particles or droplets of fuel together with air molecules, in particular, oxygen. The present invention creates this fine mist without the need of electrical elements and without moving parts.
The fuel/air mixture is introduced to the internal combustion engine's intake manifold by way of two avenues, the invention's concentric cylinder micromixing outlet ( 30 ) and internal core micromixing outlet ( 32 ). The fuel/air mixture that enters the engines intake manifold has lost all rotation and enters as a fine mist that is more readily combusted than in regular carburetion.
Turning now to FIG. 4 . FIG. 4 is a cross-sectional view of the invention's concentric cylinders ( 12 ) that serve to illustrate an alternative embodiment of the present invention that includes a warm air induction means, a warm air inductor ( 38 ) and a warm air induction channel ( 40 ). For purposes of clarity, the invention's external cone body has been eliminated from this illustration. As noted earlier, fuel and air processed by a standardized carburetion process produces high velocity, highly turbulent fuel/air mixtures.
The present invention uses a diffusing crown ( 14 ) to initially diffuse such velocity and turbulence and allow for better mixing of fuel air molecules. As an adjunct to the diffusing crown ( 14 ), the invention also provides for a warm air inductor ( 38 ) to introduce heat into the concentric cylinder ( 12 ) via warm air induction channels ( 40 ) and thus diffuse, or slow, such rotation and velocity to an even greater degree, in particular, as the warm air introduced into the misting or micromixing apparatus housing ( 1 ) crosses chamber exchange openings ( 28 ).
Turning now to FIG. 5 . FIG. 5 is a top view showing one form of the invention's warm air induction means. The invention's warm air induction means is a hollow fitting ( 38 ) that enters into the misting or micromixing apparatus housing ( 1 ) and introduces warm air through warm air induction channels ( 40 ). Warm air is provided to the hollow fitting ( 38 ) by a flexible tubing ( 39 ) attached to, e.g., a standardized carburetor ( 2 ) automatic choke mechanism. Consequently, warm air is introduced into the invention's concentric cylinder ( 12 ) to assist in diffusing, or slowing, fuel/air mixture rotation and velocity.
Turning now to FIG. 6 . FIG. 6 is provided to further detail one form of the invention's internal core micromixing outlet ( 32 ) and the concentric cylinder micromixing outlet ( 30 ). FIG. 6 also serves to depict a bolting mechanism ( 16 ) that may be provided in multiple arrangements within a same misting or micromixing apparatus manifold ( 1 ) so that it fits engines produced by different manufacturers. Likewise, the carburetor adapter ( 8 ) may be molded to match the misting or micromixing apparatus manifold ( 1 ) and the particular attachment points of a particular manufacturer's carburetor to engine manifold.
FIG. 7 provides a side, external view showing an alternative embodiment of the invention's exterior cone body ( 11 ), the invention's diffusing crowns ( 14 ), suppressed channel ( 26 ) and chamber exchange opening ( 28 ). In this configuration, the chamber exchange openings ( 28 ) run vertically along the shaft of the misting or micromixing concentric cylinder ( 12 ), in this case, within the suppressed channels ( 26 ). Also depicted are chamber exchange openings ( 28 ) that run horizontally around the shaft of the misting or micromixing concentric cylinder ( 12 ), which in combination with the vertically aligned openings ( 28 ), ensure that the rotation of the fuel/air mixture is stopped and serves to cause further mixing of the fuel/air mixture.
Turning now to FIG. 8 . FIG. 8 provides cross-sectional illustration showing the interior alternative embodiment of the invention's interior core ( 36 ), pressure differentiations protrusion ( 35 ) and chamber exchange openings ( 28 ). Through the main opening 45 , the fuel/air mixture that enters the misting or micromixing concentric chamber ( 12 ) passes through a series of expansion and contraction zones in which the pressure, velocity and rotation of the mixture changes. To increase the mixing of the fuel/air mixture the chamber exchange of openings ( 28 ) cause for the expansion and contraction of the fuel and air mixture, not unlike the turbulence that is formed at the edges of aircraft wings.
In fact, it is this type of turbulence that causes the present invention to increase fuel efficiency by reducing fuel consumption of engines fitted with the present invention as measured in decreased fuel consumption at 700 and 1,674 rpm (See Table I). An increase of 10 percent in horsepower was obtained with a concurrent decrease of fuel consumption of 30 percent at 700 rpm and 20 percent at 1,674 rpm. The amount of carbon monoxide was also decreased at both rpms measured. The present invention was tested using the two barrel configuration in an Oldsmobile 1987 with a 387 eight cylinder engine. The drop in fuel/air mixture density caused by the turbulence also leads to decreased contamination as measured by a decrease in carbon monoxide output, while concurrently increasing engine power and performance.
TABLE I
Internal Carburetor Combustion Engines
Normal Measurements of Carbon Monoxide from 10 to 14%
Misting or micromixing Apparatus in V-8
Normal Engine V-8
Engine
HIGH
HIGH
LOW
3,500 R.P.M.
1,674 R.P.M.
700 R.P.M.
C—O = 6% to 7%
C—O = 1.89%
C—O = 0.50%
H C − 300%
H C − 303%
H C − 537%
CO 2 12 to 14%
CO 2 12.2%
CO 2 14.0%
O 2 1.1%
O 2 1.3%
LOW R.P.M.
C—O = 1. to 1.2
C—O = 0.50
While this invention has been described in reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments. | The present invention is a micromixing apparatus for creating a closer union of fuel and air molecules, in combination with an internal combustion engine and fuel supply, that includes a variable width cylinder designed to fit within a housing, the interior and exterior of the cylinder defining at least two paths; and a variable width interior core positioned within the variable width cylinder, whereby fuel and air molecules that travel along the length of the variable width cylinder and interior core change in speed and volume as they travel through the at least two paths defined by the cylinder and the interior core. | 8 |
The present application claims the benefit of U.S. Provisional Application Ser. No. 60/607,602, filed Sep. 7, 2004, which application is incorporated herein by reference. The present application further incorporates by reference the related patent application for “Phase Equalization for Multi-Channel Loudspeaker-room Responses” filed on Sep. 7, 2005.
BACKGROUND OF THE INVENTION
The present invention relates to signal processing and more particularly to cross-over frequency selection and optimization for correcting the frequency response of each speaker in a speaker system to produce a desired output.
Modern sound systems have become increasingly capable and sophisticated. Such systems may be utilized for listening to music or integrated into a home theater system. One important aspect of any sound system is the speaker suite used to convert electrical signals to sound waves. An example of a modern speaker suite is a multi-channel 5.1 channel speaker system comprising six separate speakers (or electroacoustic transducers) namely: a center speaker, front left speaker, front right speaker, rear left speaker, rear right speaker, and a subwoofer speaker. The center, front left, front right, rear left, and rear right speakers (commonly referred to as satellite speakers) of such systems generally provide moderate to high frequency sound waves, and the subwoofer provides low frequency sound waves. The allocation of frequency bands to speakers for sound wave reproduction requires that the electrical signal provided to each speaker be filtered to match the desired sound wave frequency range for each speaker. Because different speakers, rooms, and listener positions may influence how each speaker is heard, accurate sound reproduction may require to adjusting or tuning the filtering for each listening environment.
Cross-over filters (also called base-management filters) are commonly used to allocate the frequency bands in speaker systems. Because each speaker is designed (or dedicated) for optimal performance over a limited range of frequencies, the cross-over filters are frequency domain splitters for filtering the signal delivered to each speaker.
Common shortcomings of known cross-over filters include an inability to achieve a net or recombined amplitude response, when measured by a microphone in a reverberant room, which is sufficiently flat or constant around the cross-over region to provide accurate sound reproduction. For example, a listener may receive sound waves from multiple speakers such as a subwoofer and satellite speakers, which are at non-coincident positions. If these sound waves are substantially out of phase (viz., substantially incoherent), the waves may to some extent cancel each other, resulting in a spectral notch in the net frequency response of the audio system. Alternatively, the complex addition of these sound waves may create large variations in the magnitude response in the net or combined subwoofer and satellite speaker response.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the above and other needs by providing a system and method which provide a least a single stage optimization process which optimizes flatness around a cross-over region. A first stage determines an optimal cross-over frequency by minimizing an objective function in a region around the cross-over frequency. Such objective function measures the variation of the magnitude response in the cross-over region. An optional second stage applies all-pass filtering to reduce incoherent addition of signals from different speakers in the cross-over region. The all-pass filters may be included in signal processing circuitry associated with either each of the satellite speaker channels or the subwoofer channel or both, and provides a frequency dependent phase adjustment to reduce incoherency between the satellite speakers and the subwoofer. The all-pass filters may be derived using a recursive adaptive algorithm or a constrained optimization algorithm. Such all-pass filters may further be used to reduce or eliminate incoherency between individual satellite speakers.
In accordance with one aspect of the invention, there is provided a method for minimizing the spectral deviations of the net subwoofer and satellite speaker response in a cross-over region. The method comprises measuring the full-range (i.e., non bass-managed or without high pass or low pass filtering) subwoofer and satellite speaker response in at least one position in a room, selecting a cross-over region, selecting a set of candidate cross-over frequencies and corresponding bass-management filters for the subwoofer and the satellite speaker, applying the corresponding bass-management filters to the subwoofer and satellite speaker full-range response, level matching the bass-managed subwoofer and satellite speaker response, performing addition of the subwoofer and satellite speaker response to obtain a net bass-managed subwoofer and satellite speaker response, computing an objective function using the net response for each of the candidate cross-over frequencies, and selecting the candidate cross-over frequencies resulting in the lowest objective function. The method may further included an additional step of all-pass filtering to further attenuate the spectral notch.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
FIG. 1 is an example of a multi-channel 5.1 layout in a room.
FIG. 2 is a prior art signal processing flow for a home theater speaker suite.
FIG. 3 shows typical magnitude responses of subwoofer and satellite speaker bass-management filters.
FIG. 4A is a frequency response for a subwoofer.
FIG. 4B is a frequency response for a satellite speaker.
FIG. 5 is a combined subwoofer and satellite speaker magnitude response having a spectral notch for an incorrect choice of cross-over frequency
FIG. 6 is a signal processing flow for a prior art signal processor including equalization filters.
FIG. 7A is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 30 Hz.
FIG. 7B is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 40 Hz.
FIG. 7C is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 50 Hz.
FIG. 7D is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 60 Hz.
FIG. 7E is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 70 Hz.
FIG. 7F is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 80 Hz.
FIG. 7G is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 90 Hz.
FIG. 7H is a combined satellite speaker and subwoofer magnitude response for a cross-over frequency of 100 Hz.
FIG. 8 is a signal processor flow according to the present invention including all-pass filters.
FIG. 9 shows a speaker suite magnitude response without all-pass filtering and with all-pass filtering.
FIG. 10A is a first method according to the present invention.
FIG. 10B is a second method according to the present invention.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.
A typical home theater 10 is shown in FIG. 1 . The home theater 10 comprises a media player (for example, a DVD player) 11 , a signal processor 12 , a monitor (or television) 14 , a center speaker 16 , left and right front speakers 18 a and 18 b respectively, left and right rear (or surround) speakers 20 a and 20 b respectively, a subwoofer speaker 22 , and a listening position 24 . The media player 11 provides video and audio signals to the signal processor 12 . The signal processor 12 in often an audio video receiver including a multiplicity of functions, for example, a tuner, a pre-amplifier, a power amplifier, and signal processing circuits (for example, a family of graphic equalizers) to condition (or color) the speaker signals to match a listener's preferences and/or room acoustics.
Signal processors 12 used in home theater systems 10 , which home theater systems 10 includes a subwoofer 22 , also generally include cross-over (or bass-management) filters 30 a - 30 e and 32 as shown in FIG. 2 . The subwoofer 22 is designed to produce low frequency sound waves, and may cause distortion if it receives high frequency electrical signals. Conversely, the center, front, and rear speakers 16 , 18 a , 18 b , 20 a , and 20 b are designed to produce moderate and high frequency sound waves, and may cause distortion if they receive low frequency electrical signals. To reduce the distortion, the unfiltered signals 26 a - 26 e provided to the speakers 16 , 18 a , 18 b , 20 a , and 20 b are processed through high pass filters 30 a - 30 e to generate filtered speaker signals 38 a - 38 e . The same unfiltered signals 26 a - 26 e are processed by a lowpass filter 32 and summed with a subwoofer signal 28 in a summer 34 to generate a filtered subwoofer signal 40 provided to the subwoofer 22 .
An example of a system including a prior art signal processor 12 as described in FIG. 2 is a THX® certified speaker system. The frequency responses of THX® bass-management filters for subwoofer and satellite speakers of such THX® certified speaker system are shown in FIG. 3 . Such THX® speaker system certified signal processors are designed with a cross-over frequency (i.e., the 3 dB point) of 80 Hz and include a bass management filter 32 preferably comprising a fourth order low-pass Butterworth filter (or a dual stage filter, each stage being a second order low-pass Butterworth filter) having a roll off rate of approximately 24 dB/octave above 80 Hz (with low pass response 44 ), and high pass bass management filters 30 a - 30 e comprising a second order Butterworth filter having a roll-off rate of approximately 12 DB per octave below 80 Hz (with high pass response 42 ).
While such THX® speaker system certified signal processors conform to the THX® speaker system standard, many speaker systems do not include THX® speaker system certified signal processors. Such non-THX® systems (and even THX® speaker systems) often benefit from selection of a cross-over frequency dependent upon the signal processor 12 , satellite speakers 16 , 18 a , 18 b , 20 a , 20 b , subwoofer speaker 22 , listener position, and listener preference (in the present application, the term “satellite speaker” is applied to any non-subwoofer in the speaker system). In the instance of non-THX® speaker systems, the 24 dB/octave and 12 dB/octave filter slopes (see FIG. 3 ) may still be utilized to provide adequately good performance. For example, individual subwoofer 22 and non-subwoofer or satellite speaker 16 , 18 a , 18 b , 20 a , and 20 b (in this example the center channel speaker 16 in FIG. 2 ) full-range frequency responses (one third octave smoothed), as measured in a room with reverberation time T 60 of approximately 0.75 seconds, are shown in FIGS. 4A and 4B respectively. As can be seen, the center channel speaker 16 has a center channel frequency response 48 extending below 100 Hz (down to about 40 Hz), and the subwoofer 22 has a subwoofer frequency response 46 extending up to about 200 Hz.
The satellite speakers 16 , 18 a , 18 b , 20 a , 20 b , and subwoofer speaker 22 , as shown in FIG. 1 generally reside at different positions around a room, for example, the subwoofer 22 may be at one side of the room, while the center channel speaker 16 is generally position near the monitor 14 . Due to such non-coincident positions of the speakers, if the cross-over frequency is not carefully selected, sound waves near the cross-over frequency may add incoherently (i.e., at or near 180 degrees out of phase), thereby creating a spectral notch 50 and/or other substantial amplitude variations in the cross-over region shown in FIG. 5 . Such spectral notch 50 and/or amplitude variations may further vary by listening position 24 , and more specifically by acoustic path differences from the individual satellite speakers and subwoofer speaker to the listening position 24 .
The spectral notch 50 and/or amplitude variations in the crossover region may contribute to loss of acoustical efficiency because some of the sound around the cross-over frequency may be undesirably attenuated or amplified. For example, the spectral notch 50 may result in a significant loss of sound reproduction to as low as 40 Hz (about the lowest frequency which the center channel speaker 16 is capable of producing). Such spectral notches have been verified using real world measurements, where the subwoofer speaker 22 and satellite speakers 16 , 18 a , 18 b , 20 a , and 20 b were excited with a broadband stimuli (for example, log-chirp signal) and the net response was de-convolved from the measured signal.
Further, known signal processors 12 may include equalization filters 52 a - 52 e , and 54 , as shown in FIG. 6 . Although the equalization filters 52 a - 52 e , and 54 provides some ability to tune the sound reproduction for a particular room environment and/or listener preference, the equalization filters 52 a - 52 e , and 54 do not generally remove the spectral notch 50 , nor do they minimize the variations in the response in the crossover region. In general, the equalization filters 52 a - 52 e , and 54 are minimum phase and as such often do little to influence the frequency response around the cross-over.
The present invention provides a system and method for minimizing the spectral notching 50 and/or response variations in the crossover region. While the embodiment of the present invention described herein does not describe the application of the present invention to systems including equalization filters for each channel, the method of the present invention is easily extended to such systems.
Known signal processors 12 (see FIG. 1 ) include a capability to select one of a set of cross-over frequencies. For example, the Denon® AVR—5805 receiver has selectable cross-over frequencies in 10 Hz increments from 20 Hz through 200 Hz, and at 250 Hz (i.e., 20 Hz, 30 Hz, 40 Hz, . . . 200 Hz, 250 Hz). An optimal cross-over frequency might be found through a gradient descent optimization, with respect to the 3 dB frequency of the bass-management filter (for example, a Butterworth filter), and a corresponding objective function could be the error between the resulting magnitude response and a zero dB or flat response, around the cross-over region. However, such gradient descent optimization is unnecessarily complicated. Because the choice of cross-over frequency is generally limited to a finite set of frequencies, a simple and effective method to select an optimal cross-over frequency is to characterize the effect of the choice of each available cross-over frequency based on the net subwoofer-satellite speaker magnitude response in the cross-over region.
The home theater 10 generally resides in a room comprising an acoustic enclosure which can be modeled as a linear system whose behavior at a particular listening position is characterized by a time domain impulse function, h(n); n {0, 1, 2, . . . }. The time domain impulse response h(n) is generally called the room impulse response which has an associated frequency response, H(e jω ) which is a function of frequency (for example, between 20 Hz and 20,000 Hz). H(e jω ) is generally referred to the Room Transfer Function (RTF). The time domain response h(n) and the frequency domain response RTF are linearly related through the Fourier transform, that is, given one we can find the other via the Fourier relations, wherein the Fourier transform of the time domain response yields the RTF. The RTF provides a complete description of the changes the acoustic signal undergoes when it travels from a source to a receiver (microphone/listener). The RTF may be measured by transmitting an appropriate signal, for example, a logarithmic chirp signal, from a speaker, and deconvolving a response at a listener position. The signal at a listening position 24 consists of direct path components, discrete reflections which arrive a few milliseconds after the direct path components, as well as reverberant field components.
An objective function which is particularly useful for characterizing the magnitude response is the spectral deviation measure σ E . The spectral deviation measure σ E is a measure of the variation of the spectral response at discrete frequencies in the cross-over region, from an average spectral response Δ taken over the entire cross-over region. When the effects of the choice of the cross-over frequency are bandlimited around the cross-over region, the spectral deviation measure σ E is quite effective at predicting the behavior of the resulting magnitude response around the cross-over region. The spectral deviation measure σ E may be defined as:
σ E = [ 1 P ∑ i = 0 P - 1 ( 10 log 10 ❘ E ( ⅇ jω i ) - Δ ) 2 ]
where the average spectral deviation Δ is:
Δ = 1 P ∑ i = 0 P - 1 ( 10 log 10 ❘ E ( ⅇ jω i ) )
and the net subwoofer and satellite speaker response E(e jω ) is,
E ( e jω )= H sub ( e jω )+ H sat ( e jω )
and P is the number of discrete selectable cross-over frequencies. Alternatively, other objective functions employing a standard deviation rule (with or without frequency weighting) may be employed. An example of a typical cross-over region is between L Hz and M Hz (e.g., L=30 and M=200), and an example of a set of discrete selectable cross-over frequencies comprises frequencies between 30 Hz and 200 Hz in N Hz steps (e.g., N=10).
The Room Transfer Function H(e jω ) may be obtained using any of several well known methods. A preferred method is the application of a pseudo-random sequence to the speaker, and deconvolving the response at the listener position 24 . One such method comprises cross-correlating a measured signal with a pseudo-random sequence. A particularly useful pseudo-random signal is a binary Maximum Length Sequence (MLS).
Another method for computing the Room Transfer Function H(e jω ) comprises a circular deconvolution wherein the measured signal is Fourier transformed, divided by the Fourier transform of the input signal, and the result is inverse Fourier transformed. A preferred signal for this method is a logarithmic sweep.
The magnitude responses for an exemplar speaker system for cross-over frequencies of 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, and 100 Hz are shown in FIGS. 7A-7H . The spectral notch 50 can be seen to translate somewhat to the right, and significantly decreases in FIGS. 7F-7H . The spectral deviation measures σ E computed for each cross-over frequencies are:
Cross-over Frequency
σ E
30
1.90
40
2.04
50
2.19
60
2.05
70
1.53
80
1.17
90
0.96
100
0.83
Comparing the FIGS. 7A-7H , the spectral deviation measure σ E shows a marked decease for cross-over frequencies of 80 Hz, 90 Hz, and 100 Hz.
Thus, the cross-over frequency selection described above provides measurable attenuation of the spectral notch and/or minimization of the spectral deviations in the crossover region. In some cases, where further attenuation of the spectral notch is desired, all-pass filters 60 a - 60 e may be included in the signal processor 12 , as shown in FIG. 8 . All-pass filters 60 a - 60 e have unit magnitude response across the frequency spectrum, while introducing frequency dependent group delays (e.g., frequency shifts). The all-pass filters 60 a - 60 e are preferably cascaded with the high pass filters 30 a - 30 e and are preferably M-cascade all-pass filters A M (e j ) where each section in the cascade comprises a second order all-pass filter.
The second stage of attenuation of the spectral notch is achieved by adaptively minimizing a phase term:
φ sub (ω)−φ speaker (ω)−φ A M (ω)
where:
φ sub (ω)=the phase spectrum for the subwoofer;
φ speaker (ω)=the phase spectrum for the satellite speaker 16 , 18 a , 18 b , 20 a , or 20 b ; and
φ A M (ω)=the phase spectrum of the all-pass filter.
The M cascade all-pass filter A M may be expressed as:
A M ( ⅇ jω ) = Π k = 1 M ⅇ - jω - r k ⅇ jθ k 1 - r k ⅇ jθ k ⅇ - jω · ⅇ - jω - r k ⅇ jθ k 1 - r k ⅇ - jθ k ⅇ - jω
and the resulting frequency dependent phase shift is:
ϕ A M ( ω ) = ∑ k = 1 M ϕ A M ( k ) ( ω ) and , ϕ A M ( i ) = - 2 ω - 2 tan - 1 ( r i sin ( ω - θ i ) 1 - r i cos ( ω - θ i ) ) - 2 tan - 1 ( r i sin ( ω + θ i ) 1 - r i cos ( ω + θ i ) )
A second objective function, J(n) is:
J ( n ) = 1 N ∑ i = 1 N W ( ω i ) ( ϕ sub ( ω ) - ϕ speaker ( ω ) - ϕ A M ( ω ) ) 2
The terms r i and θ i may be determined using an adaptive recursive formula by minimizing the objective function J(n) with respect to r i and θ i . The update equations are:
r i ( n + 1 ) = r i ( n ) - μ r 2 ∇ r i J ( n ) ; and θ i ( n + 1 ) = θ i ( n ) - μ θ 2 ∇ θ i J ( n )
where μ r and μ θ are adaptation rate control parameters chosen to guarantee stable convergence and are typically between zero and one. Finally, the gradients of the objective function J(n) with respect to the parameters of the all-pass function is are:
∇
r
i
J
(
n
)
=
∑
l
=
1
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(
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(
ϕ
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(
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where
:
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(
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)
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subwoofer
(
ω
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(
ω
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ϕ
A
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,
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1
In order to guarantee stability, the magnitude of the pole radius r i (n) is preferably kept less than one. A preferable method for keeping the magnitude of the pole radius r i (n) less than one is to randomize r i (n) between zero and one whenever r i (n) is greater than or equal to one.
A first a method according to the present invention is described in FIG. 10A , and a second method according to the present invention is described in FIG. 11B . The second method is preferably performed following the first method. The first method includes the steps of measuring the full-range (i.e., non bass-managed) subwoofer and satellite speaker response in at least one position in a room at step 80 , selecting a cross-over region at step 82 , selecting a set of candidate cross-over frequencies and corresponding bass-management filters for the subwoofer and the satellite speaker at step 84 , applying the corresponding bass-management filters to the subwoofer and satellite speaker full-range response at step 86 , level matching the bass managed subwoofer and satellite speaker response at step 88 , performing addition of the subwoofer and satellite speaker response to obtain the net bass-managed subwoofer and satellite speaker response at step 90 , computing an objective function using the net response for each of the candidate cross-over frequencies at step 92 , and selecting the candidate cross-over frequency resulting in the lowest objective function at step 94 .
Computing the objective function may comprise computing the spectral deviation measure σ E , or computing a standard deviation with or without frequency weighting. Level matching is comparing the speaker response without bass-management to the speaker response with bass-management, and is preferably comparing the root-mean-square (RMS) level of the satellite speaker response, without bass-management, using C-weighting and test noise (e.g., THX test noise) to the (RMS) level of the satellite speaker response, with bass-management, using C-weighting and test noise.
The first method may further address the selection of a cross-over frequency for multiple listener locations by computing a multiplicity of objective functions (preferably computing a multiplicity of spectral deviation measures σ E ) for a multiplicity of candidate cross-over frequencies at the multiplicity of different listen locations, averaging the multiplicity of objective functions over the multiplicity of different listen locations to obtain an average objective function for each of the multiplicity of candidate cross-over frequencies, and selecting the candidate cross-over frequencies which provides the lowest average objective function.
A second method according to the present invention is described in FIG. 10B . The second method may be exercised following the first method to further attenuate the spectral notch. The second method comprises defining at least one second order all-pass filter having all-pass filter coefficients selectable to reduce incoherent addition of acoustic signals produced by the subwoofer and the satellite speaker at step 96 , recursively computing the all-pass filter coefficients to minimize a phase response error at step 98 , the phase response error being a function of phase responses of a subwoofer-room response, a satellite-room response, and the subwoofer and satellite bass-management filter responses, and cascading the all-pass filter with at least one of the satellite speaker bass-management filter and subwoofer bass-management filter at step 100
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims. | A system and method provide at least a single stage optimization process which maximizes the flatness of the net subwoofer and satellite speaker response in and around a cross-over region. A first stage determines an optimal cross-over frequency by minimizing an objective function in a region around the cross-over frequency. Such objective function measures the variation of the magnitude response in the cross-over region. An optional second stage applies all-pass filtering to reduce incoherent addition of signals from different speakers in the cross-over region. The all-pass filters are preferably included in signal processing for the satellite speakers, and provide a frequency dependent phase adjustment to reduce incoherency between the center and left and right speakers and the subwoofer. The all-pass filters are derived using a recursive adaptive algorithm. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to novel crystal polymorphs (alpha, beta, gamma, delta, zeta and eta) of a yellow disazo colorant having the chemical structure (I), to their preparation and use as pigment.
[0002] The majority of organic pigments exist in a plurality of different crystal forms, also called polymorphs. Crystal polymorphs have the same chemical composition but a different arrangement of the building blocks (molecules) in the crystal. The crystal structure determines the chemical and physical properties; consequently, the individual polymorphs frequently differ in rheology, color and other coloristic properties. The different crystal polymorphs may be identified by means of X-ray powder diffractometry.
[0003] The compound of the formula (I) is formed by coupling one equivalent of 2-chloro-N,N′-1,4-diacetoacetylphenylenediamine (II) with two equivalents of diazotized dimethyl aminoterephthalate (III), and is described in DE-A-2 058 849.
[0004] CS-A-266 632 describes the treatment of amorphous N,N′-1,4-diacetoacetylphenylenediamine azo pigments in C 1-3 alcohols or in water at increased pressures of up to 6 bar and 100-150° C. The compound of the formula (I) is not mentioned in the examples there.
[0005] The process described in DE-A-2 058 849 gives the compound of the formula (I) as amorphous product to which no crystal phase can be assigned by X-ray powder diffractometry. Amorphous crude pigment obtained in accordance with DE-A-2 058 849 possesses a cloudy reddish yellow hue, inadequate color strength, poor rheological properties, and inadequate solvent resistance, light stability and weathering stability, and in this form is of no interest from an applications standpoint.
[0006] If the pigment of the formula (I) is subjected to a solvent treatment by the process described in CS-A-266 632, the resulting product is still substantially amorphous; no crystal polymorph can be assigned to it, and it differs markedly from the phases of the invention described below. The hue and properties of the pigment thus treated also remain virtually unchanged, and render the product of no interest from an applications standpoint.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to convert the compound of the formula (I) into a form which is useful from an applications standpoint.
[0008] It has surprisingly been found that, by treatment in certain organic solvents, it is possible to produce a total of six defined, pure crystal phases of (I). The polymorphs are called α (alpha), β (beta), γ (gamma), δ (delta), ζ (zeta), and η (eta). They feature the following characteristic lines in the X-ray powder diagram (Cu—K α radiation, double the Bragg angle 2Θ in degrees, interplanar spacings d in Å −1 ):
relative α: 2Θ d intensity 6.1 14.6 100 8.2 10.8 34 9.0 9.9 13 14.1 6.3 15 15.2 5.8 6 15.8 5.6 12 17.0 5.2 6 22.1 4.0 8 23.6 3.8 8 24.0 3.7 15 24.8 3.6 8 25.3 3.5 52 26.1 3.4 29 27.3 3.3 40 28.8 3.1 17 relative β: 2Θ d intensity 9.0 21.6 44 10.6 8.3 7 15.1 5.8 8 16.0 5.5 6 16.5 5.4 9 19.5 4.5 8 22.1 4.0 11 26.9 3.3 100 27.7 3.2 17 relative γ: 2Θ d intensity 5.9 14.9 98 8.0 11.1 25 8.7 10.1 9 9.6 9.2 9 11.8 7.5 11 13.8 6.4 14 14.9 5.9 7 15.5 5.7 13 16.6 5.3 11 17.6 5.0 8 18.3 4.9 7 22.8 3.9 9 24.1 3.7 17 24.4 3.6 24 25.5 3.5 100 26.1 3.4 17 26.4 3.4 30 27.2 3.3 32 27.4 3.2 47 29.0 3.1 20 relative δ: 2Θ d intensity 5.8 15.2 63 7.9 11.2 12 9.4 9.4 6 11.6 7.6 16 13.4 6.6 6 15.1 5.9 9 16.4 5.4 9 17.2 5.2 8 18.0 4.9 8 23.2 3.8 5 23.4 3.8 5 23.7 3.8 7 24.3 3.7 17 24.6 3.6 13 25.5 3.5 100 25.8 3.4 21 26.4 3.4 22 26.9 3.3 22 27.3 3.3 41 28.6 3.1 7 28.8 3.1 11 relative ζ: 2Θ d intensity 7.0 12.6 7 8.9 9.9 23 11.2 7.9 10 11.9 7.4 48 13.2 6.7 6 14.0 6.3 7 15.1 5.9 26 17.2 5.1 37 18.0 4.9 14 18.2 4.9 27 21.5 4.1 33 21.8 4.1 27 22.6 3.9 13 23.9 3.7 100 24.7 3.6 13 25.2 3.5 17 25.9 3.4 7 26.9 3.3 76 27.1 3.3 92 27.8 3.2 7 29.9 3.0 6 31.1 2.9 7 31.7 2.8 9 32.3 2.8 7 33.0 2.7 8 relative η: 2Θ d intensity 9.0 9.9 60 11.5 7.7 6 14.1 6.3 6 16.0 5.5 23 20.1 4.4 7 21.5 4.1 16 26.8 3.3 100 27.5 3.2 7 27.9 3.2 12
[0009] All of the line positions are given to an accuracy of ±0.2°.
[0010] In the solid state, the compound of the formula (I) may also exist in a different tautomeric and/or cis/trans-isomeric form.
[0011] All of the polymorphs differ in their X-ray diffraction diagrams and in terms of their properties from the products obtained in accordance with the known processes of DE-A-2 058 849 and CS-A-266 632. The novel polymorphs are of low solubility, are strongly colored and are notable for good fastness properties and brilliant yellow colorations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The present invention provides a process for preparing crystal polymorphs of a disazo colorant of the formula (I), which comprises causing one or more solvents from the group consisting of dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, C 4 -C 20 alcohol, 1,2-dichlorobenzene, pyridine, and nitrobenzene, or combinations of these solvents with water, the water content being from 0 to 90% by weight, to act on a compound of the formula (I) or on a tautomer, cis/trans isomer or a tautomeric cis/trans isomer of the compound of the formula (I) at a temperature of at least 100° C.; this procedure is referred to below as “solvent treatment”.
[0013] To obtain a novel crystalline phase of the compound of the formula (I), it is possible to use amorphous crude pigment, another of said crystal polymorphs, or a mixture of two or more crystal polymorphs. The compound of the formula (I) may be present in the form, for example, of dry pigment, presscakes, or an aqueous suspension.
[0014] The solvent treatment takes place preferably at from 135 to 250° C., with particular preference at from 150 to 200° C. The duration of the solvent treatment is appropriately from 1 minute to 24 hours, preferably from 5 minutes to 10 hours, in particular from 10 minutes to 5 hours. It is appropriate to cool the pigment to room temperature before isolating it.
[0015] The yellow alpha (α) polymorph is obtained, for example, by dissolving pigment of the formula (I) as the beta (β) polymorph in pyridine at from 110 to 130° C. and reprecipitating it by cooling.
[0016] The beta (β) polymorph is formed, for example, by heating crude pigment of the formula (I) to from 135 to 160° C. in dimethylformamide (DMF), N-methylpyrrolidone (NMP), or a mixture of DMF or NMP with water. The crystalline, greenish yellow pigment obtained possesses a brilliant hue, high opacity and color strength, very good solvent resistance, and excellent light and weather fastness.
[0017] The yellow gamma (γ) polymorph is obtained, for example, by dissolving a pigment of the formula (I) as the beta (β) polymorph in o-dichlorobenzene at from 170 to 190° C. and reprecipitating it by cooling.
[0018] The yellow delta (δ) polymorph is obtained, for example, by dissolving pigment of the formula (I) in the beta phase in dimethyl sulfoxide at from 180 to 200° C. and causing it to crystallize slowly by cooling. The delta polymorph is also formed if nitrobenzene at from 140 to 210° C. is used as solvent instead of dimethyl sulfoxide.
[0019] The zeta (ζ) polymorph is obtained, for example, by dissolving pigment of the formula (I) in the form of the beta phase in dimethylformamide at from 135 to 160° C., cooling the solution to below 50° C., and overlaying it with methanol. Yellow pigment crystallizes as the zeta (ζ) polymorph.
[0020] The eta (η) polymorph is obtained, for example, by heating amorphous crude pigment of the formula (I) to from 170 to 190° C. in o-dichlorobenzene, without dissolving it completely, and then cooling it again. The pigment possesses a brilliant greenish yellow hue, high opacity and color strength, and very good solvent, light and weather fastness.
[0021] Depending on the purity of the starting materials, the concentrations, the applied temperatures and temperature programs, any aftertreatment, the pressure, the presence of impurities or additives, and the presence of seed crystals, the crystal polymorphs may be obtained in pure form or as a mixture of the different polymorphs.
[0022] A pure or predominantly pure polymorph is formed preferably by starting from a solution already containing seed crystals of the desired polymorph, and cooling the solution with sufficient slowness, or adding a second solvent at a sufficiently slow rate, that the supersaturation is held within a range in which the rate of crystal growth is relatively high while the rate of crystal seed formation is relatively low, so that the existing crystal seeds grow while retaining the polymorph. The use of a mechanical stirrer may be of advantage, since it breaks down existing crystals of the desired polymorph into a large number of smaller fragments, which may then serve in turn as crystal seeds for the desired polymorph (in a process known as secondary nucleation).
[0023] If a supersaturation is higher, for example, because the solution is cooled more rapidly or a second solvent is added more rapidly, the rate of crystal seed formation is much higher, with the result that many crystal seeds of different polymorphs may form spontaneously; in this case, mixtures of different polymorphs are obtained preferentially.
[0024] The invention additionally provides a mixture of the disazo colorant of the formula (I) comprising at least 10%, preferably at least 25%, in particular at least 50%, with particular preference at least 75%, with very particular preference at least 90%, of the alpha polymorph, of the beta polymorph, of the gamma polymorph, of the delta polymorph, of the zeta polymorph, of the eta polymorph or of a mixture of two, three, four, five or six of these polymorphs.
[0025] To facilitate the preparation of the desired polymorph, to stabilize the desired polymorph, to enhance the coloristic properties, and to achieve particular coloristic effects it is possible to add pigment dispersants, surface-active agents, defoamers, extenders or other additives at any desired points of the process. It is also possible to use mixtures of these additives. The additives may be added all at once or in two or more portions. The additives may be added at any point in the synthesis or in the various aftertreatments (heating with a solvent, recrystallization, grinding, kneading), or following the aftertreatments. The point in time that is best suited must be determined beforehand by means of rangefinding tests.
[0026] Depending on the desired field of application it may be sensible to subject the resulting pigment to mechanical fine division. The fine division may be carried out by wet or dry grinding.
[0027] Pigments of the formula (I) as the inventive alpha, beta, gamme, delta, zeta or eta polymorphs are suitable for pigmenting coating materials and plastics, for producing printing inks and aqueous or solventborne pigment preparations, and for coloring seed.
[0028] Pigments of the formula (I) as the beta or eta polymorph possess high color strength and unusually good light stability and weathering stability, and are notable for brilliant greenish yellow colorations. They are therefore especially suitable for coloring coating materials.
[0029] The inventive polymorphs of the pigment of the formula (I) are suitable as colorants in electrophotographic toners and developers, such as one- or two-component powder toners (also called one- or two-component developers), for example, magnetic toners, liquid toners, latex toners, addition polymerization toners, and specialty toners.
[0030] Typical toner binders are addition polymerization, polyaddition and polycondensation resins, such as styrene, styrene acrylate, styrene butadiene, acrylate, polyester, and phenol-epoxy resins, polysulfones, polyurethanes, individually or in combination, and also polyethylene and polypropylene, which may contain further ingredients, such as charge control agents, waxes or flow aids, or may be subsequently modified with these additives.
[0031] The inventive polymorphs are of further suitability as colorants in powders and powder coating materials, especially in triboelectrically or electrokinetically sprayable powder coating materials that are used to coat the surfaces of articles comprising, for example, metal, wood, plastic, glass, ceramic, concrete, textile material, paper or rubber.
[0032] Powder coating resins employed typically comprise epoxy resins, carboxyl- and hydroxyl-containing polyester resins, polyurethane resins and acrylic resins together with customary curing agents. Resin combinations are also employed. For example, epoxy resins are frequently used in combination with carboxyl- and hydroxyl-containing polyester resins. Examples of typical curing components (depending on the resin system) are acid anhydrides, imidazoles, and also dicyandiamide and its derivatives, blocked isocyanates, bisacylurethanes, phenolic and melamine resins, triglycidyl isocyanurates, oxazolines, and dicarboxylic acids.
[0033] Furthermore, the inventive polymorphs are useful as colorants in inks, preferably ink-jet inks, such as those on an aqueous or nonaqueous basis, for example, in microemulsion inks, and in those inks which operate in accordance with the hot-melt process.
[0034] Ink-jet inks generally contain a total of from 0.5 to 15% by weight, preferably from 1.5 to 8% by weight, (calculated on a dry basis), of one or more of the inventive polymorphs.
[0035] Microemulsion inks are based on organic solvents, water and, if desired, an additional hydrotropic substance (interface mediator). Microemulsion inks contain from 0.5 to 15% by weight, preferably from 1.5 to 8% by weight, of one or more of the inventive polymorphs, from 5 to 99% by weight of water, and from 0.5 to 94.5% by weight of organic solvent and/or hydrotropic compound.
[0036] “Solvent based” ink-jet inks contain preferably from 0.5 to 15% by weight of one or more inventive polymorphs, and from 85 to 99.5% by weight of organic solvent and/or hydrotropic compounds.
[0037] Hot-melt inks are based generally on waxes, fatty acids, fatty alcohols or sulfonamides which are solid at room temperature and liquefy on heating, the preferred melting range being between about 60° C. and about 140° C. Hot-melt ink-jet inks consist substantially, for example, of from 20 to 90% by weight of wax and from 1 to 10% by weight of one or more of the inventive polymorphs. It is also possible for from 0 to 20% by weight of an additional polymer (as “dye dissolver”), from 0 to 5% by weight of dispersing aids, from 0 to 20% by weight of viscosity modifiers, from 0 to 20% by weight of plasticizers, from 0 to 10% by weight of tack additive, from 0 to 10% by weight of transparency stabilizer (which prevents, for example, crystallization of the waxes), and from 0 to 2% by weight of antioxidant to be present. Typical additives and auxiliaries are described, for example, in U.S. Pat. No. 5,560,760.
[0038] In addition, the inventive polymorphs are also useful as colorants for color filters, both for additive and for subtractive color generation, and for coloring seed.
[0039] In the examples below parts and percentages are by weight. The crystal polymorph of the products obtained is determined by means of X-ray powder diffractometry.
EXAMPLES
Comparative Example 1
Synthesis of Crude Pigment
[0040] Dimethyl aminoterephthalate is diazotized by the process of DE-A-2 058 849, example 54 and coupled with 2-chloro-1,4-N,N′-diacetoacetylphenylenediamine. This gives a reddish yellow amorphous crude pigment of chemical structure (I), to which no crystal polymorph can be assigned.
Comparative Example 2
Finish According to CS-A-266 632
[0041] Amorphous crude pigment of the formula (I) from comparative example 1 is suspended in ethanol and the suspension is heated to 130° C. in an autoclave and stirred for 8 hours. After cooling, the product is filtered off and washed. This gives a substantially amorphous reddish yellow pigment of chemical structure (I), to which no crystal polymorph can be assigned.
Example 1
Preparation of the Beta Polymorph
[0042] Amorphous pigment of the formula (I) in the form of an aqueous presscake is suspended in dimethylformamide, water is distilled off until the temperature of the liquid phase is 140° C., and the suspension is stirred for 30 minutes. After cooling, it is filtered and the solid product is washed. This gives a crystalline, greenish yellow pigment of chemical structure (I) as the beta polymorph.
Example 2
Preparation of the Beta Polymorph
[0043] Amorphous pigment of the formula (I) is suspended in N-methylpyrrolidone, the suspension is stirred at 150° C. for 3 hours, cooled and filtered, and the solid product is washed. This gives a crystalline, greenish yellow pigment of chemical structure (I) as the beta polymorph.
Example 3
Preparation of the Alpha Polymorph
[0044] A pigment of the formula (I) as the beta polymorph is dissolved in boiling pyridine at 120° C. and slowly reprecipitated by cooling the solution. Filtration and washing give a crystalline yellow pigment of chemical structure (I) as the alpha polymorph.
Example 4
Preparation of the Gamma Polymorph
[0045] Pigment of the formula (I) as the beta polymorph is dissolved in boiling
[0046] o-dichlorobenzene at 180° C. and slowly reprecipitated by cooling the solution. Filtration and washing give a crystalline yellow pigment of chemical structure (I) as the gamma polymorph.
Example 5
Preparation of the Delta Polymorph
[0047] Pigment of the formula (I) as the beta polymorph is dissolved in dimethyl sulfoxide at 190° C. On cooling, a solid crystallizes which is filtered off and dried. This gives a crystalline yellow pigment of chemical structure (I) as the delta polymorph.
Example 6
Preparation of the Delta Polymorph
[0048] Pigment of the formula (I) as the beta polymorph is dissolved in nitrobenzene at 155° C. and reprecipitated by slow cooling. Filtration and washing give a crystalline yellow pigment of chemical structure (I) as the delta polymorph.
Example 7
Preparation of the Zeta Polymorph
[0049] Pigment of the formula (I) as the beta polymorph is dissolved in boiling dimethylformamide at 155° C. and, after cooling, is overlaid with five times the amount of methanol. A yellow solid crystallizes, and is isolated. This gives a crystalline yellow pigment of chemical structure (I) as the zeta polymorph.
Example 8
Preparation of the Eta Polymorph
[0050] Amorphous pigment of the formula (I) is suspended in 1,2-dichlorobenzene and the suspension is stirred at 170° C. for 3 hours. It is subsequently cooled and filtered, and the solid product is washed. This gives a crystalline yellow pigment of chemical structure (I) as the eta polymorph.
Application Examples
[0051] Five parts of the pigment from example 1 are dispersed in 95 parts of an aromatic-containing alkyd melamine resin varnish.
[0052] The resulting colorations have a brilliant, greenish yellow hue, high color strength, and very good hiding power. In comparison, coating materials prepared using pigments from comparative examples 1 and 2 are markedly redder and cloudier in hue. Moreover, their hiding power is low, they are difficult to disperse, and the rheological properties of the coating materials are poor. From an applications standpoint, these pigments are markedly inferior to the inventive polymorphs. | The invention relates to six new crystal polymorphs, α (alpha), β (beta), γ (gamma), δ (delta), ζ (zeta), and η (eta), of the disazo colorant of the formula I,
having characteristic reflections in the X-ray diffraction spectrum. The novel crystal polymorphs are prepared by treatment in organic solvents. | 2 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 14/517,479, filed Oct. 17, 2014, which is a continuation of U.S. application Ser. No. 13/220,260, filed Aug. 29, 2011. The entire content of both prior-filed applications is hereby incorporated by reference.
BACKGROUND
[0002] The invention relates to detection and locating of heavy machine teeth, specifically the use of radio frequency identification (RFID) tags to determine when a metal tooth is no longer on a bucket of a heavy machine.
[0003] Heavy machines (e.g., mining equipment such as draglines and shovels) utilize steel teeth in their bucket designs. The teeth are used for several reasons: They provide a smaller point of surface area when digging into the earth, helping to break up the earth, and requiring less force than the larger surface area of a bucket itself In addition, the teeth provide easily replaceable wear points that save the bucket itself from wearing down. However, as a tooth wears down, there is currently no method to measure wear without physically removing the tooth.
[0004] When the teeth wear down, they typically fall off. The current method of detecting when a tooth falls off is an expensive machine vision system that looks at the bucket and detects when a tooth has gone missing. This system is extremely costly to implement, and only lets the operator know that the tooth has gone missing, not where it is. Once a crew notices a tooth is missing, they haul away an average ten truckloads of material in hopes of locating and separating out the fallen tooth. If they are unable to locate the tooth, the tooth can end up in a crusher. In addition the tooth can become stuck in the crusher and be ejected from the crusher, potentially harming other equipment.
SUMMARY
[0005] In one embodiment, the invention provides a method of monitoring a heavy machine tooth. The method includes coupling an RFID tag to the heavy machine tooth and positioning an RFID reader to read the RFID tag. The RFID reader provides an indication that the heavy machine tooth is separated from the heavy machine.
[0006] In other embodiments, the invention provides a heavy machine tooth monitoring system that includes a heavy machine tooth configured to be mounted on a bucket of a heavy machine, an active RFID tag coupled to the tooth, and an RFID reader configured to read data from the RFID tag.
[0007] In yet another embodiment, the invention provides a method of monitoring a heavy machine tooth. The method includes coupling an RFID tag to the heavy machine tooth, the RFID tag coupled to the heavy machine tooth to move with the heavy machine tooth and positioning an RFID reader to read the RFID tag. The method also includes receiving, by a controller, information from the RFID reader based on the data from the RFID tag, determining, by the controller, when the heavy machine tooth is separated from the heavy machine based on the information from the RFID reader, and determining, by the controller, diagnostic information for the heavy machine tooth based on the information from the RFID reader. In addition, the method includes providing, to a user, the diagnostic information and an indication to a user when the heavy machine tooth is separated from the heavy machine.
[0008] In still a further embodiment, the invention provides a heavy machine tooth monitoring system. The system includes a heavy machine tooth configured to be mounted on a bucket of a heavy machine, an active RFID tag coupled to the heavy machine tooth to move with the tooth, and an RFID reader configured to read data from the RFID tag, The RFID reader is further configured to provide an indication regarding the location of the tooth when the tooth separates from the bucket based on the data read from the RFID tag and provide diagnostic information regarding the heavy machine tooth based on the data read from the RFID tag.
[0009] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of an exemplary shovel.
[0011] FIGS. 2A and 2B illustrate the operation of an exemplary mining site.
[0012] FIG. 3 is an exploded view of a construction of a bucket tooth incorporating an RFID tag.
[0013] FIG. 4 is another view of the bucket tooth of FIG. 3 .
[0014] FIG. 5 is a cut-away view of the bucket tooth of FIG. 3 .
[0015] FIG. 6 is a plan view of another construction of a bucket tooth incorporating an RFID tag.
[0016] FIG. 7 is a plurality of views of a third construction of a bucket tooth incorporating an RFID tag.
[0017] FIG. 8 is a plan view of a construction of a ceramic plug for inserting an RFID tag into the bucket tooth of FIG. 7 .
[0018] FIG. 9 is a schematic diagram of a wear detection circuit.
DETAILED DESCRIPTION
[0019] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
[0020] Heavy machines are used to move large amounts of earth in industries such as mining and construction. Some heavy machines (e.g., an electric shovel) include buckets for scooping up the earth. The buckets often include a plurality of teeth to help break up the earth, and make it easier to scoop the earth into the bucket.
[0021] FIG. 1 shows an exemplary electric shovel 100 used for surface mining applications. The electric shovel 100 includes a mobile base 105 supported on drive tracks 110 . The mobile base 105 supports a turntable 115 , and a machinery deck 120 . The turntable 115 permits full 360° rotation of the machinery deck 120 relative to the base 105 .
[0022] A boom 125 is pivotally connected at 130 to the machinery deck 120 . The boom 125 is held in an upwardly and outwardly extending relation to the deck by a brace or gantry in the form of tension cables 135 which are anchored to a back stay 140 of a stay structure 145 rigidly mounted on the machinery deck 120 .
[0023] A dipper or bucket 150 includes a plurality of teeth 152 , and is suspended by a flexible hoist rope or cable 155 from a pulley or sheave 160 , the hoist rope is anchored to a winch drum 165 mounted on the machinery deck 120 . As the winch drum rotates, the hoist rope 155 is either paid out or pulled in, lowering or raising the dipper 150 . The boom pulley 160 directs the tension in the hoist rope 155 to pull straight upward on the shovel dipper 150 thereby producing efficient dig force with which to excavate the bank of material. The dipper 150 an arm or handle 170 rigidly attached thereto, with the dipper arm 170 slideably supported in a saddle block 175 , which is pivotally mounted on the boom 125 at 180 . The dipper arm 170 has a rack tooth formation thereon (not shown) which engages a drive pinion or shipper shaft (not shown) mounted in the saddle block 175 . The drive pinion is driven by an electric motor and transmission unit 185 to effect extension or retraction of the dipper arm 170 relative to the saddle block 175 .
[0024] The shovel boom 125 is a major structural component in size, shape, and weight. Its main purpose is to hold the boom pulley 160 in an advantageous position for efficient hoist dipper pull through the bank. Another major purpose of the boom 125 is to mount the shipper shaft at a sufficient height and outward radius from the centerline of rotation of the shovel 100 . The shipper shaft powers the shovel handle to extend and retract the dipper 150 . These two features of an electric shovel digging attachment make the shovel uniquely qualified to reach and dig high bank formations safely away from the shovel. The shovel in this regard is also able to reach a great volume of material in one sitting without propelling closer to the bank.
[0025] The bucket teeth 152 are removably attached to the bucket 150 . This enables broken or worn teeth 152 to be easily replaced. However, this leads to teeth 152 occasionally breaking or falling off of the bucket 150 . In some circumstances, a tooth 152 will break/fall off the bucket 150 and end up in the earth being mined (i.e., in the bucket 150 ). When the earth in the bucket 150 is deposited in a truck, the tooth 152 goes into the truck as well. Often the earth in the truck is taken to a crusher to be crushed. When the truck empties its contents into the crusher, the tooth 152 goes into the crusher as well, potentially damaging the crusher, being expelled from the crusher and damaging other equipment, or being damaged in the crusher.
[0026] FIGS. 2A and 2B represent a typical mining operation. The shovel 100 digs up earth 200 with its bucket 150 , and dumps the earth 200 into a truck 205 . Once the truck 205 is full, the truck 205 takes the earth 200 to another location (e.g., at the mining site or remote from the mining site). In some operations, the truck 205 takes the earth 200 to a crusher 210 . The truck 205 deposits the earth 200 onto a conveyor 215 which feeds the earth 200 into the crusher 210 which crushes the earth 200 into smaller components 220 .
[0027] The invention uses an active RFID tag embedded in or attached to the metal tooth 152 of the heavy machine bucket to enable detection of a tooth 152 missing from the bucket 150 .
[0028] The invention uses an RFID reader 225 located on a structure (e.g., an exit gate) through which the truck 205 passes after being filled. The RFID reader 225 checks if an RFID tag passed near the structure. If an RFID tag is detected, an alarm can be triggered enabling the truck 205 to be searched to determine if the detected RFID tag and corresponding tooth 152 was in the bed of the truck 205 . If a tooth 152 containing an RFID tag had broken/fallen off the bucket 150 and was in the truck 205 , it could be found before leaving the site or being deposited in the crusher 210 . Preferably, the RFID reader 225 is positioned a far enough distance away from the bucket 150 that the reader 225 does not detect RFID tags in the teeth 152 that are still in place on the bucket 150 .
[0029] In addition, an RFID reader 230 can be positioned before the entrance to the crusher 210 to detect the RFID tag on a tooth 152 prior to the tooth 152 entering the crusher 210 (e.g., the reader 230 could be positioned over the conveyor 215 feeding the crusher 210 ). Again, if the reader 230 detects an RFID tag, an alarm is triggered and the conveyor 215 and/or crusher 210 is/are stopped, enabling the tooth 152 to be located prior to entering the crusher 210 .
[0030] An RFID tag in a tooth 152 can include information identifying the tooth 152 . For example, the RFID tag can be written with data such as, but not limited to, a serial number, an origin, a date of manufacture, etc. This stored information can enable a user to quickly determine where the tooth 152 came from promoting faster repair of the bucket 150 or returning of the tooth 152 .
[0031] In some embodiments, an RFID reader 235 is included in the heavy machine 100 itself (see FIG. 1 ). The reader 235 reads all of the RFID tags located on the machine 100 , including the tags on the teeth 152 . A controller or computer receives information from the reader 235 about the tags detected. The controller then provides diagnostic information to a user. This information can include when the tooth 152 was installed, how many hours the tooth 152 has been in operation, etc. In addition, should a tooth 152 break/fall off, the controller alerts the user of this condition enabling the lost tooth 152 to be found quickly and replaced.
[0032] In some embodiments, additional circuitry is included with the RFID tag to determine the amount of wear of a tooth, enabling preventative maintenance to be performed before a tooth fails.
[0033] In some embodiments, the RFID tag 300 is detuned when the tooth 152 is mounted to the bucket 150 . When the tooth 152 breaks/falls off the bucket 150 , the signal strength of the RFID tag 300 increases. The reader 235 detects the increase in signal strength and determines that the tooth 152 has broken/fallen off the bucket 150 .
[0034] FIGS. 3-5 show a view of a heavy machine bucket tooth 152 . The tooth 152 includes an active RFID tag 300 encased in a ceramic enclosure 305 , the ceramic enclosure 305 is then encased in steel 310 . A separate control circuitry can also be included in the ceramic enclosure 305 to activate the RFID tag 300 when the tooth 152 is shipped or installed, saving battery power and extending the life of the RFID tag 300 . The ceramic enclosure 305 with the RFID tag 300 , and any other circuitry, is placed in a mold into which liquid steel is poured to form the tooth 152 . The ceramic enclosure 305 protects the RFID tag 300 from the heat of the liquid steel. The RFID tag 300 is detuned such that the steel of the tooth 152 tunes the RFID tag 300 to the correct frequency, using the tooth 152 as an antenna. In some embodiments, a tuning circuit in the RFID tag 300 tunes the tag 300 once the tag 300 is activated in the tooth 152 .
[0035] FIG. 6 shows another construction of a heavy machine bucket tooth 152 incorporating an RFID tag 300 . The tag 300 is mounted to an end 600 of the tooth 152 . The end 600 is inserted into a mounting bracket 605 and the tooth 152 is secured to the mounting bracket 605 . In this construction, the RFID tag 300 takes advantage of the metal of the tooth 152 and the bracket 605 , using backscattering to increase an intensity of the RFID signal.
[0036] FIG. 7 shows a construction of a heavy machine bucket tooth 152 arranged to receive an RFID tag. The tooth 152 includes a hole 700 drilled into the base of the tooth 152 . A cylindrical RFID tag is inserted into the hole 700 . In some constructions, a ceramic disk is placed over the RFID tag, and the hole 700 is welded shut.
[0037] FIG. 8 shows a construction of a ceramic plug 800 for insertion in the tooth 152 of FIG. 7 . The ceramic plug 800 encapsulates an RFID tag and a tooth wear detection circuit. Four probes 805 , 810 , 815 , 820 extend out of the ceramic plug 800 . When the ceramic plug 800 is inserted into the hole 700 of the tooth 152 , the probes 805 - 820 each contact the tooth 152 and are thereby electrically coupled to the tooth 152 . The wear detection circuit uses the probes 805 , 810 , 815 , 820 to electrically test the tooth 152 and determine the wear of the tooth 152 . The wear detection circuit provides data to the RFID tag 300 regarding the wear of the tooth 152 (e.g., amount of loss, useful life remaining, etc.). The RFID tag 300 then communicates (e.g., via a wired or wireless connection) the wear information to an RFID reader (e.g., in a cab of a shovel, to a portable RFID reader, etc.).
[0038] FIG. 9 shows a wear detection circuit 900 used to determine wear of the tooth 152 . The circuit 900 uses a four-point resistance method to determine wear. A current source 905 produces a current that is applied to two of the probes 805 and 820 . The current flowing through the probes 805 and 820 is detected by a current transducer 910 . A voltage transducer 915 of the circuit 900 detects a voltage across the other two probes 810 and 815 . Using the detected current and voltage, a microcontroller 920 of the circuit 900 determines a resistance of the tooth 152 . The resistance varies based on the material composition of the tooth 152 , the permittivity of the tooth 152 , and the dimensions of the tooth 152 . As the tooth 152 wears, the resistance of the tooth 152 changes. The change in resistance can thus be used to determine the wear and tear on the tooth 152 . In some embodiments, the initial resistance (i.e., when the tooth 152 is new) is recorded in the RFID tag 300 . Also, in some embodiments, other resistance measurements (e.g., the resistance previously determined) are recorded in the RFID tag 300 .
[0039] Various features and advantages of the invention are set forth in the following claims. | Methods and systems for tracking heavy machine teeth. One system includes a heavy machine tooth configured to be mounted on a bucket of a heavy machine, an active RFID tag coupled to the heavy machine tooth to move with the tooth, and an RFID reader configured to read data from the RFID tag, The RFID reader is further configured to provide an indication regarding the location of the tooth when the tooth separates from the bucket based on the data read from the RFID tag and provide diagnostic information regarding the heavy machine tooth based on the data read from the RFID tag. | 4 |
This application is a continuation-in-part of application Ser. No. 06/169,309 filed 07/16/80 which is a continuation-in-part of Ser. No. 06/061,471 filed 07/07/79 both now abandoned.
BACKGROUND OF THE INVENTION
The present application is directed to a process and apparatus for treating of a heat treatable strap-like material by heating the same to a particular temperature as it is passed through a heat zone. In particular, the process and apparatus are advantageously used for heat treating of a ferrous metal product by raising the temperature thereof to a temperature in the range of about 800° to 1600° F. The process and apparatus result in precision heating of the material being treated by heating the same using high intensity infrared radiation in a controlled environment where the amount of heat input to the strap can be closely controlled.
Infrared radiation and particularly high intensity infrared radiation can be produced by elongate tubes as manufactured by General Electric and a number of applications have been suggested for this radiation as outlined in a Research Inc. brochure, entitled "Infrared Radiant Heat Invisible Tool for Today's Energy Conscience Industry".
In applying infrared radiation in continuous treating of heat treatable strapping and the like, problems occur with respect to lamp burn-out as the life of the lamp rapidly decreases with high operating temperatures and problems occur with respect to the structure for supporting the lamps particularly when a controlled atmosphere is required to avoid oxidization of the metal strap or the like, which is being treated. Heat treating of these products requires the temperture of the product to be raised in a range of 800° to 1800° F. or more and sealing problems between infrared radiation reflecting surfaces occurs due to the extreme temperature range the reflectors are subject to. As mentioned, this problem becomes acute when a controlled atmosphere is required whereby the structure must be designed to keep air and oxygen out of at least a portion of the heat treating zone.
The problems with respect to the operating temperature to which the structure is exposed is overcome in the application of the present process by providing a gas flow through the heat zone sufficient to frequently turn over the atmosphere within the heat zone to remove heat from the structure. In contrast to earlier processes, the atmosphere is frequently turned over to be relatively cool and there is no attempt to directly recycle the heat in the atmosphere back to the material being treated. The cool environment allows a net positive heat flow from the strap or material being treated to the atmosphere. Such an arrangement maintains a cool environment about the strap or product being treated whereby changes in the intensity of the radiation emitted by the lamps, both positive and negative cause a similar change in the energy absorbed by the strap and hence the temperature thereof. This results in a precise process and avoids damage caused by over heating of the strap due to secondary heat sources or due to momentary errors where the intensity emitted by the lamps is too great. It must be recognized that high intensity infrared radiation can rapidly raise the temperature of a thin substrate, such as strap or wire and the like, and, therefore, it is important to be able to have the temperature of the product responsive to positive and negative changes in the radiation emitted by the lamps.
Apparatus of the present invention discloses a simple structure for treating of the product where infiltration of ambient air is reduced to a point that it does not effect the product being treated. The apparatus provides a flow of inert gas over the product being treated as it is moved through the structure to envelop the strap and thereby avoid oxidization on the surface of the strap. Again, this flow of gas is such that it is at a temperature below that of the product being treated, at least when the product is near its final heat treat temperature where over heating of the strap or product could occur if the radiation emitted by the lamps is momentarily to high. This cool environment allows the temperature of the strap to be responsive to both positive and negative changes in the radiation emitted by the lamps. It can appreciated that when the strap or product is at a temperature much less than the final temperature being sought, it is not as important for the gas flow to be below the temperature of the product as a slight overshoot in the temperature would not be a problem, as it would still be below the final temperature to which the strap is be raised.
SUMMARY OF THE INVENTION
The process of the present invention is used in heat treating metal strapping wire and the like as the same is passed through a heat zone raising the temperature of the metal to a predetermined temperature range in the range of about 800° F. to 1600° F. depending upon the material being treated and the material property sought to be obtained.
The process comprises passing the metal to be treated through the heat zone along a generally straight path past opposed banks of high intensity infrared radiation lamps
energing the lamps to produce high intensity short wave infrared radiation to heat the metal to be treated,
sensing the temperature of the material adjacent the exit of the heat zone,
controlling the intensity of radiation emitted by the lamps by varying the input energy to the lamps in accordance with at least the sensed temperature of the metal adjacent the exit of the heat zone to maintain the metal temperature at the exit of the heat zone within the predetermined range,
introducing sufficient air into the heat zone to flow over and cool the lamps and maintain them within their normal operating temperature range and to cause a flow of air along and enveloping the material to be treated, prior to positively exhausting the air from the heat zone,
the introduction and exhaust of air from the heat zone being sufficient to frequently turn-over the atmosphere within the heat zone and cause the air about the material being treated to be at a temperature causing a net positive heat flow from the material to be treated to the atmosphere whenever the material to be treated is at a temperature in excess of about 500° F.
The process for heat treating a heat treatable strapping wire or the like as the same is passed through a heat zone, raises the temperature of the ferrous metal to be in the range of about 800° to 1600° F., depending upon the material being treated and the material property sought to be obtained, and requires a controlled atmosphere to minimize oxidization on the surface of the metal being treated. The process comprises passing the metal to be treated through the heat zone along a generally straight path past opposed banks of infrared radiation lamps which provide the sole original heat source for determining the temperature to which said material is to heated. The lamps are energized to produce high intensity short wave infrared radiation to heat the metal and the temperature of the material adjacent the exit of the heat zone is sensed. This sensed temperature is used to control the intensity of the radiation emitted by the lamps by changing the input energy to the lamps in accordance with at least the sensed temperature to maintain the metal temperature at the exit of the heat zone within a predetermined range. A gas flow is introduced at the exit of the heat zone and flows along the metal being treated in a direction opposite the direction of travel of the metal being treated to provide a controlled atmosphere about the strap. The gas flow envelops the metal at least adjacent the exit of the heat zone and in the region where the material to be treated is at a temperature which would cause oxidization unless protected by the gas flow. The gas of the flow is non-oxidizing with respect to the metal being treated and preferrably is nitrogen. Air is introduced into the heat zone to cool the lamps and maintain a cool air environment at points which do not require a controlled atmosphere. Sufficient air and controlled atmosphere are positively exhausted at a position within the heat zone to provide a pressure differential between the exit of the heat zone and the exhaust position which results in the gas flow along and enveloping the material to be treated. The exhaust of air and gas from the heat zone is sufficient to frequently turn over the atmosphere within the heat zone and to retain the atmosphere about the material being treated at a temperature causing a net heat flow from the material to be treated to the atmosphere at least adjacent the exit of the heat zone.
According to an aspect of the invention, the gas introduced, at least adjacent the exit of the heat zone, is nitrogen gas at an appropriate pressure and temperature to expand at least about three times in volume to the exhaust pressure and, thereby, displace and maintain exhaust air out of contact with the strap having a temperature which could cause oxidization if exposed to an oxidizing atmosphere.
According to a further aspect of the invention, the atmosphere within the heat zone is continually exhausted to cause a sufficient flow through the heat zone to maintain the structure thereof at a temperature less than about 500° F.
According to yet a further aspect of the invention, the process is capable of start-stop operation and includes the strap of purging at least the portion of the zone having the controlled gas atmosphere with a greater flow of gas upon stopping of the strap to immediately cool any hot spots within the heat zone produced by undesired continuous exposure to the radiation emitted for the purpose of heating of the material to be treated.
The heat zone, according to the present invention, comprises a opposed banks of high intensity infrared radiation lamps extending across the heat zone defined by opposed side walls and opposed end walls. The side walls include a length of ceramic blanket material exterior to ceramic board panels positioned in abutting relationship. The panels and blanket are secured to support members with the blanket being resistant to infiltration of ambient air and the panels having a reflective surface exposed within the heat zone for reflecting high intensity infrared radiation emitted by the lamps for heating of the material being treated.
According to an aspect of the invention, the end walls include opposed ceramic blankets each extending the length of the end walls separated by lamp support panels which receive the lamps and allow the same to pass therethrough for electrical connection to a supply exterior to the heat zone.
According to a further aspect of the invention, the lamps have extended tubes with each tube having a cathode and anode intermediate the length of the tube. The lamps are secured by the end walls with the anode and cathode between the end walls. This allows the anode and cathode to be fully exposed within the heat zone and to allow cooling thereof by the flow of gas atmosphere and/or air through the heat zone.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings wherein;
FIG. 1 is partial perspective view of the heat zone structure;
FIG. 2 is a partial side view of the heat zone structure which has been divided into two sections, one of which requires a controlled atmosphere;
FIG. 3 is a section taken along line 3--3 of FIG. 1;
FIG. 4 is a partial perspective view showing the support of the lamps within the end walls of the heat zone;
FIG. 5 is section taken along line 5--5 of FIG. 1; and
FIG. 6 is a cross section taken along line 6--6 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The heat treating zone structure 10 of FIG. 1, has opposed side walls 12 and opposed end walls 14 secured at the corners by generally vertically extending upright structural members 16. Beyond the end walls 14, and running generally parallel therewith are cover members 18 which define a conduit through which an air flow is forced as generally indicated by arrow 26. This air flow provides cooling of the end walls and provides cooling of the lamp tips to increase the life expectancy of the infrared radiation emitting lamps or tubes 36. Each side wall has a plurality of infrared reflecting panels 20, which define the interior surface of the side walls of the heat treating zone and reflect infrared radiation which inpinges thereon. Behind the infrared reflecting panels 20, is a continuous ceramic blanket 22 which extends from the bottom of the heat zone to at least a point where air infiltration into the interior of the heat zone is no longer critical. It is preferred that this ceramic blanket extends the full height of the heat zone which will have an inert gas atmosphere flowing therethrough. The ceramic blanket in combination with the operating pressure of the atmosphere within the heat zone, makes infiltration of ambient air to be minimal, if at all, and out of contact with the product requiring protection. Exterior to the ceramic blanket is a side cover made of steel or aluminum to prevent damage to the blanket. The panels 20, the ceramic blanket 22 and the cover 24 are secured by bolts 28, positioned at the corner of the panels and passing through the upright member 16.
The end walls 14, comprise transite panels 30 having apertures therein for receiving and supporting the infrared radiation emitting lamps 36. The transite panels are covered on the inside by a ceramic blanket 32 and covered on the exterior thereon by a ceramic blanket 34. The ceramic blankets 32 and 34 are slit to allow the lamps 36 to pass therethrough, in a manner that the ceramic blanket 32 and 34 engages the lamp and provides a seal therewith. The ceramic blankets 32 and 34 as well as the ceramic blanket 22 of the side walls are fairly flexible in their initial state, however, when exposed to the higher tempertures of the heat zone, they become somewhat more rigid and the flexibility is lost. This is not a problem as the lamps have already been put in place prior to exposing the ceramic blankets to the higher temperature, and replacement of a single lamp if necessary can still be accomplished. Nut and bolt arrangement 38, secure the ceramic blanket 34 and 32 as well as the transite panels 30 in place.
In building of the heat treat zone structure 10, the side walls are built by proper placement of the panels 20 and the ceramic blanket 22 with the end walls left open to provide access to the interior of the zone. After these components have been put in place, the ship lap joint, generally indicated as 21 in FIG. 5, between the panels 20 is filled on the interior surface with a sealing compound. This sealing compound is referred to in the trade as a moldable ceramic suitable for the maximum operating temperature of the zone and will be placed at the abutment of the ship lap joint of the panels 20 as well as at the corners of the panels and the upright members 16. After the side walls 12 have been properly assembled, the end walls are built up by proper securing of the transite panels 30, and the ceramic blanket 32 and 34. It has been found that the ceramic blanket 32 and 34 can be made of a 3/8" thickness, whereas it is preferred that the ceramic blanket of the side walls be about 1/2" in thickness. In addition, the panels 20 are manufactured by Crown Company Limited of St. Catherines and referred to as "M Boards 2600." These are approximately 1" thick, and will withstand temperature up to approximately 2600° F. It has been found that these boards tend to warp as they are exposed to temperatures approaching the miximum, and although the heat zone is not intended to heat the product to 2600° F., it has been found that these boards are superior with respect to maintaining their shape relative to similar boards having a maximum temperature of about 2000° F. These earlier boards were subject to warpage deformation and shrinkage rendering the structure prone to leakage of ambient air. The higher temperature boards are not as prone to shrinkage and warpage and the use of the ceramic moldable sealant to seal the panel joints, accommodates minor shrinkage, and tolerance variation, and assembly problems.
In FIG. 2, a product 40 that has been heat treated and passed about the exit rollers 44 and 46. The exit 48 of the heat zone structure 10, has a gas conduit 72 located for introducing an inert gas which is non-oxidizing relative to the product, such as strap wire and the like, which is being treated. The gas which is introduced as indicated by arrow 60, envelops the product being treated adjacent the exit of the heat zone, and continues to flow along the strap and protect the strap or product up until a point such as 74, which is within the second stage 52 of the heat treating structure 10. Point 74 has been arbitrarily selected, however, it represents a possible initial point where the strap is at a temperture which requires an inert gas atmosphere to prevent oxidation. The location of this point will be a function of the material being treated and the temperature of the product at this point. Point 74, is located below the air inlet 82 to avoid oxidization of the product. An air flow 84 comes through the air inlet 82 and is exhausted by the exhaust fan 78, through the exhaust conduit 80. This provides a flow of ambient air across the heat zone and removes heat from beneath the baffle 54 which separates the second stage 52 of the heat zone treating structure 10, from the first stage 50. The first stage, due to the temperature to which the strap or product is being raised, up to about 900° F., does not require an inert atmosphere and, therefore, does not require the additional expense of maintaining a flow of inert gas along the product being treated to envelop the same. Also adjacent the exit 48 of the heat zone is an optical pyrometer 90, which senses the temperature of the strap and appropriately increases or decreases the input energy to the infrared radiation lamps 36, which have been arranged in opposed banks 56 and 58. The inert atmosphere such as nitrogen, is introduced through the gas conduit 72, and is at a temperature and pressure which will cause the gas introduced to expand at least about three times the volume to atmospheric pressure which is the pressure approximately at the exhaust conduit 80. Therefore, a positive pressure bias exists between the introduction of the inert gas at adjacent the exit 48 and the point of exhaust from the heat zone indicated adjacent conduit 80, and the heat zone is at a pressure slightly above atmosphere. Similarily the exhaust conduit 80 causes the air flow 84 to be maintained in the upper region of the second stage of the heat zone and away from the point 74 requiring an inert gas atmosphere. It is preferred that the exit 48 of the heat zone 10 is the point of introduction of the inert gas and separates the heat zone from other structures, such as a lead bath which could be immediately below the exit 48. It is preferred to introduce the strap directly into a lead bath, however, fumes from the lead bath are preferrably not introduced into the heat zone as they can contaminate the quartz tubes of the lamps and cause a rapid decrease in the life expectancy of the lamps. For example, it has been found that fumes from the lead bath can contaminate a small point on a lamp and cause the same to burn through the quartz destroying the tube. It is preferred that the gas within the heat zone be physically separated from other structures, even though the structures below the heat zone will probably also require a controlled atmosphere. Possibly the same gas inlet could be used for both, however, they should be separately exhausted, and the gas above the lead bath should not flow into the heat zone and contact the lamps.
The lamps 36, as shown in FIG. 3, are of an extended length where the tungston filament of the tube is located substantially intermediate the length of the tube. This allows the tube to pass through the ceramic blanket 32, the transite panel 30 and the ceramic blanket 34 with the filament located intermediate the end walls of the heat zone. The life expectancy of the lamps 36 can be substantially increased by positioning the filament intermediate the end walls of the heat zone as the heat thereof can be dissipated along the tube and removed by the gas flow moving past the lamps.
Further cooling of the lamps is provided by the gas flow between the end walls and the cover 18. It has been found that with the high intensity radiation emitted by and the close spacing of, the lamps, that clear quart tubes are preferred rather than frosted quartz. It is believed that the clear quartz is not as prone to hot spots within the length of the tube which result in small pin holes occurring after use of the tubes. It has also been found that it is preferrable to use lamps of higher voltage capacity, such as capable of a voltage in the range of about 270-280 volts, such that the lamps do not run at maximum output at all times. The life expectancy of the lamps can be significantly increased if the output thereof is more in the range of 75% of maximum output, rather than very close to maximum output which would be required with lamps having a voltage capacity of 220-240 volts. It has been found that if contamination of the lamps should occur, the lamps must be thoroughly cleaned and the life expectancy of the lamps will decrease substantially should the lamps be run without cleaning, under the false impression that the contamination will burn off. What has been found is that small pin holes occur at points of contamination and the lamp will be ruined.
In a stop/start heat treating application it has been found that if the line is stopped the second stage of the heat zone should be immediately purged with an additional flow of gas to remove heat from the heat zone and to avoid structural hot spots which could cause localized damage of the strap or product being treated. Nitrogen gas is preferrably introduced at the rate of approximately 260 SCFM at a pressure of about 50 PSI and a temperature of about 80° F. to cool the structure and lamps to a temperature of about 400° F. or less. The normal running temperature of the structure other than the lamps is about 500° F. or less. The exhaust fan exhausts the gas atmosphere and the introduced ambient air at the rate of approximately 3000 CFM. This results in heat being removed from the heat zone structure to an extent that the actual structure has an average temperature quite low and the outer walls of the heat treating zone have a temperature of about 100° F. The structural components can be made of aluminum and, therefore, the temperature thereof must be kept well below 600° F., which could result in structural failure.
The exhaust fan 78, causes a slight negative pressure adjacent the inlet to the exhaust conduit 80, whereby a pressure bias exists between the introduced gas 60 and the slight negative pressure adjacent the exhaust conduit 80. This slight negative pressure also provides a pressure bias urging the air flow across baffle 54 to remove heat therefrom and maintains the air flow above point 74 requiring the inert gas atmosphere. The structure of the side walls and end walls results in an essentially air tight structure and leakage of ambient air is further minimized as the structure is under a minimal positive pressure due to the introduced nitrogen.
The heat zone structure may require rebuilding from time to time, such as lamp replacement or lamp cleaning, as but one example, and in this case the end walls are removed and the side walls can normally remain intact. It has been found that the tower can easily be built by removing the transite panels 30 from the end walls, and upon rebuilding of the tower inserting the necessary lamps and using new ceramic blankets 32 and 34. In this way, the side walls of the heat zone remain intact and the down time for rebuilding of the heat zone structure is considerably reduced. It can also be appreciate that the lamps are easily inserted through the blankets as they only require slitting and do not require trimming.
It is important that both the inert gas atmosphere which flows through the heat zone structure and the ambient air flow which is introduced to exhaust heat be positively exhausted. Positive exhaust maintains sufficient cooling of the structure and maintains a relatively cool environment about the strap whereby the temperture of the strap is highly reactive to changes, both positive and negative in the input energy to the infrared radiation lamps. These lamps which are producing high intensity infrared radiation capable of rapidly raising the temperature of the strap several hundred degrees. Therefore, it is important that the strap be in an environment where the temperture of the strap at least when the strap temperature is in excess of about 500° F. (and preferably 350° F.) responds rapidly with changes in the level of radiation intensity. This precision is further required as the thickness of the material being treated is often quite thin and, therefore, the mass thereof is quite small which can result in the very rapid rising of this temperature if the strap did not directly respond with the input energy to the lamps. The atmosphere is frequently exhausted to assure a net positive heat flow from the material treated to the atmosphere flowing thereover at least when the material is at a temperature of about 500° F. or more. The lamps are very fast reacting to changes in their energy input level which is controlled by the optical pyrometer 90. The optical pyrometer 90, senses the exit temperature of the strap. By sensing this temperature and appropriately controlling the input energy of the lamps, it has been found that the final strap temperature can be maintained within a very narrow range, for example, approximately plus or minus 10 degrees or 5°, and allows very accurate control of strap temperature and hence acurate control of the property sought to be desired in the material. The flow of cool gas over the product being treated allows stop/start operation without the product exceeding the maximum temperature of the predetermined range, as the radiation of the lamps can be interrupted immediately resulting in an immediate end to a rise in product temperature as heat is constantly flowing to the atmosphere at least adjacent the exit of the heat zone.
The entire heat zone could have a flow of inert gas therethrough and it is not essential that air be introduced into the heat zone for removing heat therefrom. However, the cost for such a structure and process would be higher and can be partially avoided by providing an ambient flow of air across or along the strap at a position which does not require the controlled atmosphere, by appropriately restraining the flow so that it cannot contaminate the strap being treated at a temperature which requires the controlled atmosphere. In the structure shown in FIG. 2, the flow of nitrogen gas over the strap is in a direction opposite to the direction strap travel and the flow of nitrogen will tend to maintain the flow of ambient air in the upper region of the second stage of the heat zone. The gas so introduced is at the lowest temperature when the material being treated is at the highest temperature resulting in a higher net heat flow to the atmosphere adjacent the exit of the heat zone where temperature overshoots due to slow response to changes in radiation emitted would be particularly troublesome.
This structure is advantageously used in combination with a quench bath or controlled cooling if necessary, to obtain the desired properties. The heating zone is capable of raising steel strapping wire and the like to a temperature of about 1800° F. while the same is passed through the tower. Typical strap speeds of 110 to 150 feet per minute can be achieved for a strap gauge of 0.015" to 0.030" with a tower of a length of about 25 feet, raising the temperature of the strap to about 1600° F. The tower has 820 lamps horizontally disposed in opposed banks with a vertical spacing between lamps of about 1.5" to 2" and a horizontal spacing between lamps of about 8". The lamps are of the T3 type high intensity short wave radiation lamps sold by Sylvania or General Electric. Higher speeds can be achieved by lengthening the tower or running the system close to maximum. The above speeds are achieved at about 75% of full power. For stress relieving requiring a final temperature of about 1000° F. speeds for the same gauge strap and tower length would be about 150 feet per minute to 275 feet/min. The product to be treated is raised to the desired temperature in less than about 20 seconds.
In the continuous processing of steel strapping wire, tubing, sheet material, the present process and apparatus automatically accommodates changing speeds below a predetermined maximum, changing reflective properties with respect to short wave infrared radiation, changing gauges between different products to be treated, changing gauge of product as it is treated changing ambient, once the product has been brought up to operating speed. The optical pyrometer measures final temperature and automatically appropriately varies the input energy to the lamps. According to one embodiment, only about the final third of second stage of the heat zone are controlled by the pyrometer as the other lamps merely serve to bring the product up to a temperature close to the desired temperature for completion by the remaining controlled lamps.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims. | The structure of the present invention rapidly heats metal strapping, wire and the like to a temperature in the range of about 800° F. up to about 1800° F. while maintaining accurate control on the final temperature using a simple control system. The heating process is also relatively simple and easily installed and controlled. The process and structure is easily adjusted for other applications such as paint drying. Short wave high intensity lamps have been closely spaced to provide for the rapid increase in product temperatures and gas flow through the heat zone maintains the structural elements at temperatures well below the heat treating temperatures and preferrably below about 500° F. | 2 |
BACKGROUND OF THE INVENTION
This invention is directed to an apparatus for securing a pipe to a structural element wherein the pipe penetrates through the element by passing through a hole in the element. The apparatus includes a first and second wedge shaped member each having at least one rib attaching to the base. The members are located in the hole and the members are moved with respect to one another such that the bases can be spread apart from one another. When one member is firmly lodged against the side of the hole and the other member firmly lodged against the pipe the ribs are suitably joined to one another in a permanent manner fixing the pipe in the hole.
Modern construction techniques make use of concrete slabs or layers which can serve as floor for one layer and a ceiling for the layer below it in multistory structures. In pouring of the slabs appropriate voids can be included in the slabs for passage of suitable utility conduits through the structure. Alternately after the slab is formed the concrete can be cored to provide suitable holes for passage of the necessary utility conduits. In any event, however, the slabs are formed and provided with suitable holes through which the utility conduits for the structure flow in a vertical manner.
With the expansion of plastic technology, metallic pipes used for plumbing are systematically being replaced. Plastic hot and cold inlet pipes are now commonly found in place of the prior used galvanized pipes or copper tubing. Recently building codes have been modified to allow the use of large diameter PVC and other plastic pipe for drainage risers in place of heavier iron or clay pipes. These drainage risers hereinafter simply referred to as pipes, travel vertically through the structure and must pass through the utility cut outs in the individual cement slabs forming the partitions between floors and ceilings. Appropriate expansion couplings must be used along the length of these pipes to accommodate for thermal expansion and contraction. Because of the presence of such expansion couplings and because of the necessity of systematically supporting the weight of the pipe along its total vertical dimension it is necessary to appropriately fasten the pipe to each of the individual cement slabs.
In fastening the above noted pipes along their vertical length, of course, boring into the pipe and perforating its interior is precluded. Any attaching methods for holding the pipe to the individual slabs must simply engage only the outside of the pipe and not penetrate into its interior. Flanges or the like could be utilized to clamp around the pipe and then rest on the flooring side or top edge of each slab. This, however, is disadvantageous in that the portion of the flange resting on the upper surface of the slab must be accounted for and therefore the presence of such flanges require increases in the dimension of appropriate wall sections wherein a flange might be located therein or build up of the floor area above the flange in order to hide or mask it.
In view of the above it is evident that there exists a need for a method for attaching vertical running large diameter piping to the individual cement slabs in high-rise or medium-rise structures. Preferredly such attaching must not extend beyond the perimeter of the hole passing through the cement slab but should be incorporated totally within the hole. Of course, any means for attaching pipes must consider the economics of both manufacture of the attaching device as well as the labor costs in installing it. The cost savings of utilizing plastic pipe for drainage risers would be totally negated if in fact the cost to secure these risers to each individual level became a significant portion of the costs of the pipes.
BRIEF DESCRIPTION OF THE INVENTION
In view of the above it is a broad object of this invention to provide an apparatus for securing vertical rising pipes to a structure element such as a floor, wall or ceiling wherein the pipe penetrates through the elements through a hole in the elements. It is a further object to provide such an apparatus which is easily and conveniently used by the installers of the same yet once installed will fixly and securely hold the pipe to the elements. It is an additional object to provide a device that is both economical to manufacture and to install and thus increase the economic advantage of using plastic pipes over that of other materials.
These and other objects as will become evident from the remainder of this specification are achieved in an apparatus for securing a pipe to a structural wall, floor or ceiling element wherein said pipe penetrates through said element by passing through a hole in said element which comprises: a first member and a second member; each of said members including a base having a first end and a second end; each of said members having at least one rib attaching essentially perpendicular to said base of said member and extending between the ends of said base, said ribs on each of said members tapering from said first end to said second end of the base to which it is attached such that in side view each of said members is wedge shaped; said first and said second members locatable in said hole next to said pipe such that said first end of said first member is oriented toward said second end of said second member and said second end of said first member is oriented toward said first end of said second member positioning said second end of each of said member against the rib of the other of said members and a portion of each of said ribs of said first and second members in a side by side relationship so as when said first ends of each of said members are brought closer together said bases of said first and said second member are extended away from each other one impinging against said pipe and the other impinging against the walls of said hole.
Preferredly each of the members would have two or more ribs spaced apart from each other such that a void existed between each two adjacent ribs. The ribs would be located in essentially parallel relationship such that the voids were also parallel with the ribs. When one of the members was fitted onto the other of the members a portion of the ribs of one of the members would fit into the voids of the other of the members and visa versa. The presence of two or more ribs provides for increased surface area for solvent welding of the first member to the second member and thus increases the strength and load carrying ability of the weld between the members.
In one embodiment of the invention the members would be identical each having the same number of ribs and voids and would not require the production of two separate components or a necessity of having two separate components when installing the same. In a second embodiment the members would not be identical but would be individually formed. As so formed in this second embodiment one of the members could have one more rib than the other of the members such that the member with the lesser number of ribs would have its ribs sandwiched in between the ribs of the member with the greater number of ribs.
The surface of the ribs could be formed as smooth surfaces which would be appropriately joined together by suitable solvent welding techniques or they could be formed as convoluted surfaces increasing their surface area per unit volume. The use of convoluted surfaces would allow for certain amount of frictional engagement between the ribs of one member with the ribs of the other member and also allow for a greater surface area for solvent adhasion when the two members were solvent welded together.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention described in this specification will be more fully understood when taken in conjunction with the drawings wherein:
FIG. 1 is an oblique view of the invention as used in holding a pipe within the interior of a hole through which the pipe penetrates a structural element;
FIG. 2 is an elevational view in partial section taken about the line 2--2 of FIG. 1;
FIG. 3 is an oblique view of the individual components of the invention and showing the components exploded away one from the other from the position shown in FIGS. 1 and 2;
FIG. 4 is a plan view in section about the line 4--4 of FIG. 2;
FIG. 5 is an oblique view of an embodiment of the invention and shown in a manner as is the embodiment shown in FIG. 3;
FIG. 6 is a plan view in section of the embodiment of FIG. 5 showing how the individual components of the embodiment fit together;
FIG. 7 is an oblique view of a further embodiment of the invention and shown in the manner of FIG. 3;
FIG. 8 is a plan view in section showing how the components of FIG. 7 fit together.
The invention described in this specification and illustrated in the drawings utilizes certain principles and/or concepts as are set forth and claimed in the claims apended to this specification. Those skilled in the plumbing arts to which this invention pertains will readily realize and appreciate that these concepts and/or principles could be applied to a number of differently appearing or differently describable embodiments differing from the explicite illustrative embodiment described herein. For this reason this invention is not to be construed as being limited to the exact embodiment shown for illustrative purposes but is only to be construed in light of the apended claims.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1, 2 and 3 a first embodiment of the invention is shown. Referring to FIGS. 1 and 2 the apparatus 10 of the invention is shown fixedly holding a pipe 12 in place within a hole 14 formed in a structural element 16. The structural element 16 represents a layer serving as a combination floor for one level and ceiling for the level below it as is found in a typical high-rise building. Normally such a layer, element or slab would be formed of poured concrete incorporating sufficient structural steel therein to meet strength requirements etc. The hole 14 is formed in the element either by locating a cylindrical object in place prior to pouring of the concrete or by boring of an appropriate cylindrical element out of the concrete with a typical concrete saw or the like. In any event, hole 14 is formed within the element 16 and serves as the utility access between the individual floors of the building or the like.
Normally the pipe 12 would be a large diameter PVC pipe such as 4" or 6" pipe. This large diameter pipe would serve as the drainage riser for the building or the like wherein the pipe was located. It is necessary to render the pipe immobile with regard to the structural element 16 for several reasons. The first of these would be to provide vertical support of the pipe along the length it must travel. Considerable weight and force can be generated along a long section of pipe of a multistory building. The second requirement would be to isolate the pipe within the hole 14 such that it is not subject to horizontal or lateral movement. This would insure that the pipe does not vibrate within the hole 14 causing the emission of audible sound waves which would be disturbing to the occupants of the building or causing frictional rubbing of the pipe against the edges of the hole 14 abrading the surface of the pipe 12.
The apparatus 10 successfully positions the pipe within the hole 14 and prevents both vertical and horizontal movement of the pipe 12 within the hole 14. This securely holds the pipe 12 to the structural element 16 and prevents horizontal movement which would be both detrimental to the pipe itself and the source of environmental noise polution.
In FIGS. 2 and 3 it can be seen that the apparatus 10 consists of a first member 18 and a second member 20. Two such apparatuses 10 are shown in FIG. 2 one holding the left side of the pipe and one holding the right side of the pipe. However, as seen in FIG. 1 the line 2--2 of FIG. 1 is not a straight line but is in fact a bent line. Preferredly three or four of the apparatuses 10 would be utilized to isolate the pipe 12 within the hole 14. For economy of both purchase of the apparatus and installation of the apparatus three such apparatuses 10 would be sufficient to fixly secure pipe 12 within the structural element 16.
In FIG. 3 first member 18 and second member 20 are shown as independent and distinct articles. They are, infact, identical and are only rotated with respect to one another. If the right hand edge of member 18 in FIG. 3 were rotated counterclockwise 180° it would produce second member 20. In describing the respective parts of the first and second members 18 and 20, since they are identical, identical numbers will be used for identical respective parts. Thus the same numbers will be used in reference to part of both members 18 and 20. Identification of parts might be made on one or the other of members 18 or 20 depending which of these particular members the individual components are best seen in.
A base 22 forms the backbone structure of the members 18 and 20. The base 22 is essentially a rectangular plate. The base 22 extends from first end 24 longitudinally to second end 26. An end piece 28 is located at first end 24 and extends perpendicular to the base 22. Extending between the end piece 28 on first end 24 toward and tapering down to second end 26 are ribs 30, 32 and 34. Located between ribs 30 and 32 is void 36. Located between ribs 32 and 34 is void 38. The ribs 30, 32 and 34 are spaced away from one another and are placed in parallel planes. The spacing between each of the ribs is such that the voids 36 and 38 are slightly wider than each of the ribs 30, 32 and 34. This allows the ribs of member 18 to appropriately fit into the voids of member 20 and conversely the ribs of member 20 to fit into the voids of member 18.
The upper surface 40 of rib 30, the upper surface 42 of rib 32 and the upper surface 44 of rib 34 all lie on a plane which tapers toward the plane of the base 22. This taper is smooth throughout most of the length of the ribs 30, 32 and 34 except at a point near end 26. At this end the upper surface 46 of rib 30, the upper surface 48 of rib 32 and the upper surface 50 of rib 34 tapers more sharply toward end 26. The angle produced between the surfaces 46, 48 and 50 and the base 22 is therefore greater than the angle produced between the surfaces 40, 42 and 44.
Referring now to FIG. 2 it can be seen that members 18 and 20 can be brought together such that end 26 of member 18 is oriented toward end 24 of member 20 and likewise end 26 of member 20 is oriented toward end 24 of member 18. When this happens the two members 18 and 20 can be brought together such that the second ends 26 of each of the respective members 18 and 20 are positioned adjacent to the upper surfaces 40, 42 and 44 of the ribs 30, 32 and 34 on the other of the members. Because the upper surfaces 46, 48 and 50 near ends 26 of members 18 and 20 makes a larger angle with base 22 than is the remainder of these upper surfaces 40, 42 and 44 of the respective ribs 30, 32 and 34, a certain portion of each of the ribs 30, 32 and 34 engages into the voids 36 and 38 of the opposite member 18 or 20 respectively. The amount of each of the ribs 30, 32 and 34 which would become located within the voids 36 and 38 is dependent on the angle of the upper surfaces 46, 48 and 50 with the base 22. By enlarging this angle a greater amount of each of the ribs can penetrate into the voids of the opposite member. By decreasing this angle a lesser amount of each of the ribs would fit into the voids on the other member. Normally about 1/8 to 1/4 inch of the ribs will fit into the opposite voids when the overall length of the members 18 and 20 is about 6 inches.
Edge 52 on end 26 of both members 18 and 20 is a straight edge. When the members 18 and 20 are brought together this edge 52 abutts against the upper surfaces 40, 42 and 44 of the ribs. The members 18 and 20 can be moved longitudinally with respect to one another by sliding this edge 52 along the upper surfaces 40, 42 and 44 of the ribs 30, 32 and 34. When this happens because of the general overall wedge shape of the members 18 and 20 the respective bases 22 of these two members 18 and 20 will be positioned parallel to one another and will move away from and toward each other while still maintaining their parallet relationship. In this manner the spacing between the two bases of the two members 18 and 20 can be increased or decreased by sliding the members 18 and 20 with respect to one another. When the first ends 24 of each of the members 18 and 20 are slid away from each other the respective bases 22 come closer together and when these first ends 24 of the respective members 18 and 20 are brought closer toward one another the respective bases 22 separate from each other. The pipe 12 can therefore be securely impinged within the hole 14 by bringing the ends 24 of the members 18 and 20 toward each other, spreading the bases 22 of each of these members away from each other until one of the bases contacts the surface of the wall 14 and the other of the bases contacts the surface of the pipe 12.
In using the apparatus 10 one of the members 18 or 20 is positioned within the hole 14 and the other of the members 18 or 20 is appropriately coated with solvent or glue along its ribs 30, 32 and 34 and slid into place engaging the other member. The two ends 24 of the two members are brought together until the surfaces 22 of the respective members are one against the side of the hole 14 and one against the pipe 12. This is done in a very easily and convenient manner and in a few moments the solvent or glue will be sufficiently tacky to hold the two members in a fixed relationship with one another. After appropriate setting time of the solvent or glue the members 18 and 20 become fused with one another and can no longer be moved. Additionally the member 18 or 20 (the member 20 as seen in FIG. 2) which is adjacent to the pipe 12 can be solvent welded to the outside surface of the pipe 12. Since the preferred material of construction of the members 18 and 20 is PVC plastic, the same material as the pipes 12, this solvent welding of one of the members to the pipe is easily and conveniently done.
As noted above because of the increase in the angle with which surfaces 46, 48 and 50 make with the base 22 compared to the surfaces 40, 42 and 44 a portion of each of the ribs of one member will fit into the voids of the other member. If in fact the upper surfaces of the ribs 30, 32 and 34 tapered in a continuous straight line right down to edge 52 of the members then no portion of the ribs of one of the members could extend into the void of the other of the members. Alternately instead of having the surfaces 46, 48 and 50 taper at a greater degree than the remainder of the surfaces of the ribs 30, 32 and 34, end 26 of each of the members 18 or 20 could contain appropriate extensions of the voids 36 and 38 through the surface of the base 22 such that notches are provided along the edge 5. This is not preferred, however, because the preferred method of manufacture of the members 18 and 20 is by injection molding of a suitable plastic material. To form such indentations in the end 26 would require location of a positive area in the mold wherein the indentations are formed. Since this would complicate the mold it is preferable to form the members 18 and 20 as illustrated. Preferredly then by incorporating two different angles of intersection of the upper surfaces of the ribs 30, 32 and 34 with the base 22 the appropriate amount of extension of the ribs into the voids is achieved.
Referring now to FIG. 4 the members 18 and 20 are seen in a sectional view about the line 4--4 of FIG. 2 showing how the two members 18 and 20 engage with one another. In FIG. 4 the ribs of member 18 are identified by their appropriate number followed by the letter a. Likewise the ribs of member 20 are identified by their appropriate number followed by the letter b. The same numbering scheme is used to differentiate the voids between members 18 and 20. It can be seen in FIG. 4 that a portion of rib 30b of member 20 fits into void 36a of member 18. Likewise a portion of rib 32b fits into void 38a of member 18. A portion of rib 32a of member 18 fits into void 36b of member 20 and a portion of rib 34a fits into void 38b.
Rib 30a of member 18 and rib 34b of member 20 do not fit into any corresponding voids, however, they do lie adjacent to ribs on the other member. Both of the side surfaces of ribs 30b, 34b, 32a and 34a can be solvent welded to the corresponding side surfaces of their adjacent rib. One of the side surfaces of ribs 34a and 34b can be appropriately solvent welded to the other ribs. Thus in attaching members 18 and 20 to each other solvent welding of five side surfaces of the ribs can be utilized to engage the two members together. This sufficiently increases the surface area contact between the two members 18 and 20 over that which would be achieved by simply abutting one smooth wedge against the surface of a second smooth wedge. It can also easily be seen in FIG. 4 that the middle rib 34 of both members 18 and 20 can always be engaged into a void in the opposite member, however, which of the remaining ribs 30 or 34 is engaged in a void with the opposite member depends on how the two members 18 and 20 are brought together such that rib 34b becomes located in void 38a and all the other ribs and voids correspondently shifted. If so shifted, however, the same number of solvent weldable surfaces would still be maintained.
For the embodiment shown in FIGS. 1 through 4 the members 18 and 20 are formed to be identical with each other. This simplified production in that only one member need be formed and two units of this one member used to form the apparatus 10.
In FIGS. 5 and 6 a different embodiment of the invention is described. In FIGS. 5 and 6 two nonuniform members are described. Member 54 contains three ribs 56, 58 and 60. These are appropriately attached to a base 62. Member 64 contains two ribs 66 and 68 which are appropriately attached to a base 70. All of the ribs 56, 58, 60, 66 and 68 shown in FIGS. 5 and 6 contain the two angles with respect to the bases 62 and 70 as previously described. This allows for a portion of these ribs to extend into corresponding voids on the opposite member as previously described.
Member 54 contains two voids 72 and 74 whereas member 64 contains one void 76. The ribs 66 and 68 of member 64 fit into voids 72 and 74 of member 54 and the rib 58 of member 54 fits into the void 76 of member 64. The remaining ribs 56 and 60 of member 54 sandwich the two ribs 66 and 68 of the second member 64 between them. Four solvent weldable connections between the ribs of the opposite members are therefore achievable. While the number of solvent weldable connections between the two members 54 and 64 has been reduced with respect to the number achievable with members 18 and 20, the overall width of the combined apparatus formed by members 54 and 64 is less than the overall width of the apparatus formed by members 18 and 20. In certain installations wherein the same hole 14 through a structural element 16 might be used for different utility conduits it may be advantageous to reduce the amount of space the apparatus 10 takes up in the hole. In such utilizations the embodiment of FIGS. 5 and 6 as well as the embodiment of FIGS. 7 and 8 noted below would be advantageously used.
In FIGS. 7 and 8 an embodiment similar to the embodiment in FIGS. 5 and 6 is described. For this reason the same numbering system used in FIGS. 5 and 6 will be used except that each of the components will be preceeded by the numeral 100. Thus, for example, in FIGS. 7 and 8 member 154 is analegous to member 54 of FIGS. 5 and 6, etc. The ribs 156, 158, 160, 166 and 168 of FIGS. 7 and 8 differ from the ribs described in FIGS. 5 and 6 in that their surfaces are not smooth as with the previous ribs but are convoluted. The convolution of these surfaces allows for frictional engagement of the appropriate ribs with one another as well as slightly increasing their surface area. The frictional engagement between the ribs allows for temporary maintenance of the members 154 and 164 with each other during placement and construction. The convolutions also produce a slight increase in surface area therefore a slight increase of the strength of the bond between the two when the members are finally fixed in place in use.
While primarily designed to hold vertical piping within holes in concrete structural elements it is of course evident that the apparatus 10 of this invention could be utilized to hold a variety of different types of piping in different appropriate openings in other structural elements. | In high-rise and mid-rise buildings wherein a concrete slab serves as a floor for one level and a ceiling for the level below it, it is necessary to secure vertical plumbing pipes to the slab wherein the plumbing pipes penetrate the slab through holes passing between the levels. An apparatus for securing these pipes includes a first and second member. Each of the members includes a base having a first and second end. Each of the members include one or more ribs attaching perpendicular to the base and extending between the ends of the base. The ribs on each of the members taper from the first end toward the second end of the base such that in side view each of the members is wedge shape in cross-section. The first member is located in the hole in the slab adjacent to the pipe by inserting from the top and the second member is located by so inserting through the bottom. This orients the members such that the large ends of their tapers are distal from each other. The pipe is fixed to the hole by moving the members toward one another such that each slides upon the taper of the other, respectively. This spreads the base of the first and second members such that one impinges against the side of the hole and the other impinges against the pipe. The members are fixed with respect to each other by suitable solvent welding techniques or the like to fixly maintain the pipe in its location within the hole in the slab. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a piston-type compressor, in which fluid may be compressed by means of reciprocating pistons connected to a swash plate. More particularly, it relates to a guiding mechanism for reciprocating pistons, which improves control of the position of the pistons in the refrigerant compressor for an automotive air-conditioning system.
2. Description of the Prior Art
A swash plate refrigerant compressor with a variable displacement mechanism, particularly, a single head piston-type compressor suitable for use in an automotive air condition system, is disclosed in U.S. Pat. No. 4,664,604, which disclosure is incorporated herein by reference. Referring to FIGS. 1, 2, and 3, a cylinder block is accommodated in cylindrical housing 211 of a compressor. Pistons 48 are accommodated in cylinders 127 and are reciprocally movable therein. Drive shaft 115, which is driven by an engine, is rotatably supported by means of the central portion of the cylinder block and a front cover. Rotor plate 118 is mounted on drive shaft 115 and synchronously rotates with drive shaft 115. Further, swash plate 124 is tiltably mounted on drive shaft 115 and is reciprocally slidable together with spherical sleeve 129 parallel to the axis of drive shaft 115. Rotor plate 118 and swash plate 124 are connected to each other by means of a hinge mechanism. Swash plate 124 is engaged along its circumference with the interior portion of the associated piston(s) 48.
According to the above-described compressor, when drive shaft 115 is rotated, rotor plate 118 rotates together with drive shaft 115. The rotation of rotor plate 118 is transferred to swash plate 124 through the hinge mechanism. Rotor plate 118 is rotated with a surface inclined with respect to drive shaft 115, so that pistons 48 reciprocate in cylinder 127, respectively. Therefore, refrigerant gas is drawn into an inlet chamber and compressed and discharged from the inlet chamber into an associated discharge chamber, respectively.
Control of displacement of this compressor may be achieved by varying the stroke of piston 48. The stroke of piston 48 varies depending on the difference between pressures which are acting on the opposing sides of swash plate 124. This difference is created by variance between the pressure in a crank chamber acting on the rear surface 48a of piston 48 and suction pressure in cylinder 127 acting on the front surface 48b of piston 48, and acts on swash plate 124, through piston 48.
Cylinder housing 211 includes projection portion(s) 212 extending therefrom toward the interior of housing 211 and parallel to the reciprocating direction of piston(s) 48 for preventing the rotation of piston(s) 48 around its axis (their axes). In this arrangement, the frictional force between swash plate 124 and spherical sleeves 129 is generated because swash plate 124 slides in spherical sleeves 129 while rotating. Thereby, the frictional force acts on piston 48 to forcibly move them in the direction of the inner surface of cylinder 127 and urging them to rotate around the axis of piston 48.
Further, the inner surface of cylinder 127 functions to prevent piston 48 from inclining in a radial direction except for its rotation. However, it is difficult for cylinder 127 to prevent piston 48 from inclining in a radial direction when piston 48 approaches a bottom dead center position because the area of contact between piston 48 and cylinder 127 relative to the length of the piston within the cylinder decreases in comparison with that of existing near a top dead center position of piston 48, though cylinder 127 may prevent piston 48 from inclining in a radial direction when piston 48 approaches a top dead center position.
Therefore, in existing designs, pistons 48 experience rapid wear on their peripheral surfaces. As a result, compressor durability is reduced and noise and vibration of the compressor increase.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a piston-type compressor, in which the movement of a piston during reciprocation is precisely regulated by a piston guiding mechanism.
It is another object of the present invention to provide a piston-type compressor which has a superior durability. Further, such a compressor may generate less noise and vibration during operation.
According to the present invention, a compressor comprises a compressor housing including a crank chamber, suction chamber, a discharge chamber, and a cylinder block. A plurality of cylinders are formed in the cylinder block. The compressor further comprises a plurality of pistons, e.g., single head-type pistons. Each of the pistons has an end and an axis and is slidably disposed within one of the cylinders. A drive shaft is rotatably supported in the cylinder block. A plate is tiltably connected to the drive shaft. A bearing couples the plate to the pistons, so that the pistons may be driven in a reciprocating motion within the cylinders upon rotation of the plate. At least one working chamber is defined by an end of each of the pistons and an inner surface of each of the cylinders. A support portion is disposed coaxially with the drive shaft and tiltably supports a central portion of the plate. A piston guiding mechanism includes at least one first guide formed on a peripheral surface of the piston, and at least one second guide disposed within the housing for guiding the at least one first guide to slide smoothly along the at least one second guide and to prevent the piston from rotating around axis thereof or radially inclining as the piston reciprocates within the cylinders.
Other objects, features, and advantages will be understood when the following detailed description of embodiments of the invention and accompanying drawings are considered.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view of a swash plate refrigerant compressor with a variable displacement mechanism in accordance with a prior art.
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1 in accordance with one embodiment of the prior art.
FIG. 3 depicts a guiding mechanism of pistons in accordance with the prior art.
FIG. 4 is a longitudinal cross-sectional view of a swash plate refrigerant compressor with a variable displacement mechanism in accordance with the present invention.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 4 in accordance with a first embodiment of the present invention.
FIG. 6 depicts a guiding mechanism of pistons in accordance with the first embodiment of the present invention.
FIG. 7 is a cross-sectional view taken along line 5--5 of FIG. 4 in accordance with a second embodiment of the present invention.
FIG. 8 depicts a guiding mechanism of pistons in accordance with the second embodiment of the present invention.
FIG. 9 is a cross-sectional view taken along line 5--5 of FIG. 4 in accordance with a third embodiment of the present invention.
FIG. 10 depicts a guiding mechanism of pistons in accordance with the third embodiment of the present invention.
FIG. 11 is a cross-sectional view taken along line 5--5 of FIG. 4 in accordance with a fourth embodiment of the present invention.
FIG. 12 depicts a guiding mechanism of pistons in accordance with the fourth embodiment of the present invention.
FIG. 13 is a cross-sectional view taken along line 5--5 of FIG. 4 in accordance with a fifth embodiment of the present invention.
FIG. 14 depicts a guiding mechanism of pistons in accordance with the fifth embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 4, a refrigerant compressor according to this invention is shown. The compressor, which is generally designated by reference number 100, includes closed cylinder housing assembly 10 formed by annular casing 11 provided with cylinder block 111 at one of its ends, a hollow portion such as crank chamber 112, front end plate 12, and rear end plate 13. Thrust needle bearing 19 is placed between the inner end surface of front end plate 12 and the adjacent axial end surface of rotor plate 18 to receive the thrust load that acts against rotor plate 18 and, thereby, to ensure smooth operation.
The outer end of drive shaft 15, which extends outwardly from sleeve 122, is driven by an engine or motor of a vehicle through a conventional pulley arrangement (not shown). The inner end of drive shaft 15 extends into central bore 111a formed in the center portion of cylinder block 111 and is rotatably supported therein by a bearing, such as radial needle bearing 20. The axial position of drive shaft 15 may be changed by means of adjusting screw 21 which is screwed into a threaded portion of center bore 111a.
Spherical bush 23, which is placed between rotor plate 18 and the inner end of cylinder block 111, is slidably carried on drive shaft 15. Spherical bush 23 supports a slant or swash plate 24 for both nutational (e.g., wobbling) and rotational motion. Coil spring 25 surrounds drive shaft 15 and is placed between the end surface of rotor plate 18 and one axial end surface of bush 23 to urge spherical bush 23 toward cylinder block 111. Swash plate 24 is connected with rotor plate 18 through a hinge coupling mechanism for rotation in unison with rotor plate 18. More particularly, rotor plate 18 has arm portion 181 projecting axially inwardly from one side surface of rotor plate 18, and swash plate 24 has arm portion 241 projecting toward arm portion 181 of rotor plate 18 from one side surface of swash plate 24. Arm portions 181 and 241 overlap and are connected to one another by pin 26 which extends into an oblong or rectangular hole 182 formed through arm portion 181 of rotor plate 18. In this manner, rotor plate 18 and swash plate 24 are hinged to one another. In this construction, pin 26 is slidably disposed in hole 182, which causes the slant angle of the inclined surface of swash plate 24 to change.
Rear end plate 13 is shaped to define suction chamber 30 and discharge chamber 31. Valve plate member 14, which together with rear end plate 13 is fastened to the end of cylinder block 111 by screws, is provided with a plurality of valved suction ports 141 joining suction chamber 30 and respective cylinders 27.
Further, crank chamber 112 and suction chamber 30 are connected by passageway 35 which comprises aperture 351 formed through valve plate 14 and gaskets (not shown) and bore 352 formed in cylinder block 111. Coupling element 36 with small aperture 361 is disposed in the end opening of bore 352, which faces crank chamber 112, and bellows element 37 containing gas and having needle valve 371 also is disposed in bore 352. The opening and closing of small aperture 361, which is connected between crank chamber 112 and bore 35, is controlled by needle valve 371, and the axial position of bellows element 37 is determined by frame element 38 disposed in bore 352. At least one hole 381 is formed through frame 38 to permit communication between aperture 351 and bore 352.
Cylinder block 111 has a plurality of annularly arranged cylinders 27 into which pistons 28 slide. For example, cylinder block 111 may include five cylinders 27, but a smaller or larger number of cylinders may be provided. Each of single head-type piston 28 may comprise head portion 281 slidably disposed within cylinder 27, arm portion 280 axially extending from the center of head portion 281, and connection portion 282. Connection portion 282 of pistons 28 has cutout portion 282a which straddles the outer peripheral portion of swash plate 24. Semi-spherical thrust bearing shoes 29 are disposed between each side surface of swash plate 24 and face the inner surface of connection portion 282 to facilitate sliding contact along the side surface of swash plate 24.
In operation, drive shaft 15 may be rotated by an engine or motor of a vehicle through the pulley arrangement, and thus, rotor plate 18 is rotated together with drive shaft 15. Such rotation of rotor plate 18 is transferred to swash plate 24 through the hinge coupling mechanism, so that with respect to the rotation of rotor plate 18 shown in FIG. 4, the inclined surface of swash plate 24 moves axially to the right and left. Pistons 28, which are operatively connected to swash plate 24 by means of swash plate 24, slide between bearing shoes 29 and, therefore, reciprocate within cylinders 27. As pistons 28 reciprocate, refrigerant gas, which is introduced into suction chamber 30 from a fluid inlet port (not shown), is taken into each cylinder 27 through valved suction ports 141 and compressed. The compressed refrigerant gas vents to discharge chamber 31 from each cylinder 27 through discharge port 142 and therefrom into an external fluid circuit (not shown), e.g., a cooling circuit, through the fluid outlet port (not shown).
When the heat load of the refrigerant gas exceeds a predetermined level, the suction pressure is increased. For example, such a predetermined level may relate to the level set at or measured by a thermostat located in a compartment of a vehicle, which controls the temperature existing at a beginning stage or a stage from which the temperature is lowered by the operation of the compressor to a desired temperature. Therefore, in this case, the pressure of the gas contained in bellows element 37 is set at about the same level as the pressure for the predetermined heat load level, and, referring again to FIG. 4, bellows element 37 is urged toward the right side to open aperture 361. Thus, the pressure in crank chamber 112 is maintained at the suction pressure. In this condition, during the compression stroke of pistons 28, reaction force of gas compression normally acts against swash plate 24 and is finally transferred to the hinge coupling mechanism.
On the other hand, if the heat load is decreased and the refrigerant capacity is exceeded, the pressure in suction chamber 30 is decreased, referring to FIG. 4, bellows element 37 moves to the left side to close small aperture 361 with needle valve 371. In this case, the pressure in the crank chamber 112 is gradually raised, and a narrow pressure difference occurs due to blow-by gas, which leaks from the working chamber to crank chamber 112 during the compression stroke through a gap between piston 28 and cylinder 27, is contained in crank chamber 112.
Referring to FIGS. 5 and 6, connection portion 282 includes a pair of projections 284 extending radially from the peripheral surface of piston 28. Each projection 284 includes surface portion 284a formed on the radial end thereof, and groove 284b is formed substantially on the center of surface portion 284a. Further, projection 284 includes curved surface 284c formed on the radial exterior portion of piston 28, and curved surface 284d is formed on the radial interior portion of piston 28, which are also curved with respect to the inner surface of cylinder housing 11. Each groove 284b extends along and is parallel to the longitudinal axis of housing bolts 55, which penetrate through the adjacent cylinders 27. Groove 284b has a half circular shape in radial cross-section. Groove 284b of projection 284 slidably receives housing bolts 55, so that piston 28 is prevented from rotating around the axis thereof and from inclining toward all radial direction.
The frictional force between swash plate 24 and shoes 29, which is generated by the sliding of swash plate 24 within shoes 29, is transferred to piston 28 and urges piston 28 to rotate around its axis and to incline in radial directions. However, the fit between groove 284b and housing bolts 55 opposes the action of the above-mentioned rotation force R and radial forces F, as shown in FIG. 5. Therefore, the guiding mechanism prevents piston 28 from inclining in a radial direction of the compressor without requiring contact in addition to that between head portion 281 of piston 28 and cylinder 27. Thereby, wear on the peripheral surface of piston 28 may be reduced. Further, length L of piston head 281 may be shorter than that of prior art embodiments. As a result, the depth of cylinder 27 may also be designed to be shorter than that of prior art embodiments without a loss of compressor capacity. Thus, the radial length of the compressor may be reduced in order to obtain a more compact compressor.
FIGS. 7 and 8 illustrate a second embodiment of the present invention, which possesses structures and features similar to those of the first embodiment, with the exception of at least the following structures. Connection portion 582 includes a pair of surface portions 582a formed radially on both sides thereof, and a pair of projection portions 582b extending perpendicularly from surface portions 582a. Further, each of projection portion 582b is designed to be parallel to the longitudinal axis of piston 58. Each of projection portion 582b has a substantially rectangular shaped radial cross-section. Moreover, cylinder housing 11 includes a plurality of integral arms 312 extending from its inner surface toward the interior of cylinder housing 11. A pair of arms 312 are designed to be positioned corresponding to each piston 58 and are positioned at a separation which is larger than the radial width of connection portion 582. Each arm 312 includes arm portion 312a and groove 312b formed corresponding to projection portion 582b of piston 58. Each groove 312b has a substantially rectangular shaped radial cross-section. Therefore, each piston 58 is bracketed with a pair of arms 312 of housing 11, so that a pair of projection portions 582b inserts and smoothly slide in grooves 312b.
FIGS. 9 and 10 illustrate a third embodiment of the present invention, which possesses structures and features similar to those of the first embodiment, with the exception of at least the following structures. Connection portion 682 includes a pair of surface portions 682a formed radially on both sides thereof, and a pair of grooves 682b extending directly from surface portion 582a. Further, each groove 682b extends along and is substantially parallel to the longitudinal axis of piston 58. Each groove 682b also has a substantially rectangular shaped radial cross-section. Moreover, cylinder housing 11 includes a plurality of integral arms 412 extending from its inner surface toward the interior of cylinder housing 11. A pair of arms 412 are designed to be positioned corresponding to each piston 68 and are positioned at a separation which is larger than the radial width of connection portion 682. Each arm 412 includes arm portion 412a and projection 412b formed to correspond to groove 682b of piston 68. Each projection 412b has a substantially rectangular shaped radial cross-section. Therefore, each piston 68 is bracketed with a pair of arms 412 of housing 11, so that a pair of projections 412b inserts and smoothly slide in grooves 682b.
FIGS. 11 and 12 illustrate a fourth embodiment of the present invention, which possesses structures and features similar to those of the first embodiment, with the exception of at least the following structures. Connection portion 782 includes groove 784 formed in the interior of portion 782 and extending along the longitudinal axis of piston 78. Groove 784 has a rail-like shaped radial cross-section. More particularly, groove 784 may include first groove portion 784a and second groove portion 784b. Second groove portion 784b may be designed to be deeper within the interior of portion 782 than first groove portion 784a. The width of second groove portion 784b may also be designed to be larger than that of first groove portion 784a in radial cross-section. Further, cylinder housing 11 may include arm 512 extending from inner surface toward the center of cylinder 27 and along the longitudinal axis of piston 78. Arm 512 may include first arm portion 512a and second arm portion 512b extending from first projection portion 512a. Arm portion 512 also has a rail-like shaped radial cross-section. More particularly, the width of second arm portion 512b may be larger than first arm portion 512a in radial cross-section. Further, each piston 78 is connected with arm 512a of housing 11, so that arm 512 smoothly slides within groove 784 of piston 78.
FIGS. 13 and 14 illustrate a fifth embodiment of the present invention, which possesses structures and features similar to those of the first embodiment, with the exception of at least the following structures. Connection portion 882 includes projection 884 extending from the exterior surface thereof and along the longitudinal axis of piston 88. Projection 884 has a keyhole shape in radial cross-section. More particularly, projection 884 includes first portion 884a and second portion 884b further extending from first portion 884a. First projection portion 884a and second projection portion 884b have a rectangular shaped cross-section and a circular shaped cross-section, respectively. The diameter of second projection portion 884b is larger than the width of first projection portion 884a.
Compressor housing 11 may include a plurality of grooves 612 formed therein at the positions corresponding to each of cylinders 27 and extending along the longitudinal axis of piston 88. Each of groove 612 may include first groove portions 612a and second groove portions 612b. Second groove portions 612b are designed to extend deeper into the interior of housing 11 than first groove portions 612a. First groove portions 612a and second groove portions 612b also have a rectangular shaped cross-section and a circular shaped cross-section, respectively. The diameter of second groove portion 612b is larger than the width of first groove portion 612a. Further, each of piston 88 is connected with housing 11, so that projection 884 may smoothly slide in grooves 612 of housing 11.
Each of these embodiments may obtain substantially similar advantages as those described with respect to the first embodiment. Nevertheless, although the present invention has been described in connection with preferred embodiments, the invention is not limited thereto. It will be easily understood by those of ordinary skill in the art that variations and modification may be easily made within the scope of this invention as defined by the following claims. | A piston-type compressor has a compressor housing enclosing a crank chamber, suction chamber, and a discharge chamber. The compressor housing also includes a cylinder block having at least two cylinders. A single head-type piston is slidably disposed within each of the cylinders. A drive shaft is rotatably supported in the cylinder block. A plate is tiltably connected to the drive shaft. A bearing couples the plate to the pistons, so that the pistons are driven in a reciprocating motion within the cylinders upon rotation of the plate. A piston guiding mechanism has a first guiding device which is formed on the peripheral of the piston, and a second guiding device which is disposed within the housing for guiding the first guiding device to slide smoothly along the second guiding device and to prevent the piston from rotating around its axis or radially inclining when the piston reciprocates in the cylinder. Thus, the movement of a piston during reciprocating is carefully regulated, and the durability of the compressor increases. | 8 |
BACKGROUND OF THE INVENTION
[0001] The subject invention relates to an electrical connector design and an electrical connector assembly providing the alternative to have or not have a mating-assist lever to assist in the mating of two joining electrical connector halves.
[0002] In several different applications or industries, particularly in the automotive industry, electrical connector designs are standardized on various different harnesses or on various different discrete ends of a particular harness.
[0003] Just by way of example, it is common to provide as part of a wiring harness, wiring which extends into the automobile body, for example, and be connected to a mating connector at or under the driver's seat. Such connections can be used for the power seat having multiple ways of adjustment including up, back, tilt, and lumbar, as well as providing the opportunity for multiple variances of seat heating. In such an example, it would be common to provide multiple sizes of terminals depending on the power or amperage that needs to run through the cable, and thus the connectors need to accommodate multiple sizes of terminals as well.
[0004] It is also common that the connectors themselves are standardized to provide the maximum number of terminals required to accommodate all of the terminals for the maximum number of features allowable, but in the case where the seat heater or the electrical adjustment is not required, those particular terminals are not loaded. Thus, it is also common in the industry to have identical connector housings with a variety of different mating forces depending on the number of electrical terminals actually loaded in the mating connectors.
[0005] It is also common in the industry to have standardized maximum mating forces which are allowable for the assembly line in automobile plants. One such standard, known as USCAR, has designated 75 Newtons as a maximum mating force. USCAR is an umbrella organization made up of automotive manufacturers for joint research. This is the maximum force that can be designed into a connector assembly, where the two connectors are mated into a latched condition by hand including no assistance in the connection. Above the 75-Newton requirement, some type of mating assistance between the two connectors is required.
[0006] The object then of the present invention is to provide a connector design having a plurality of alternatives to accommodate all of the above-mentioned requirements.
SUMMARY OF THE INVENTION
[0007] The objects have been accomplished by providing an electrical connector assembly, comprising a first connector housing, having a first exterior profile, the exterior profile having at least a pair of engageable lugs positioned adjacent to a leading edge of the first connector housing. A first latch member is positioned adjacent to the leading edge of the first connector housing. At least one first contact member is positioned within the first connector housing. A second connector housing comprises a second exterior profile, profiled for overlappingly receiving the first exterior profile. A pair of channels is included to receive the at least one pair of engageable lugs on the first connector housing. A second latch member is positioned for latching engagement with the first latch member of the first connector housing. At least one second contact member is positioned therein, for mate able connection with the first contact member. The pair of channels have any one of a plurality of configurations, wherein the plurality of configurations include: each channel including a solid exterior wall which receives one of the pair of engageable lugs therein; or each channel may include a mounting wall having a mating assist member attached thereto, where the mating assist member is functional with the pair of engageable lugs to move the first and second connector housings into mated condition.
[0008] The first latch member may be profiled as a cantilever beam extending rearwardly away from the leading edge. The second latch member may be comprised of a raised wall, the cantilever beam of the first latch member being receivable into an area beneath the raised wall. The first and second latch members may also include first and second joining latch projections. The first latching projection may project upwardly from the cantilever beam, and the second latching projection may project downwardly from the raised wall. The pair of engageable lugs may be positioned on side walls of the first connector housing, and the first latch extends from a top wall.
[0009] The mating assist member may be a lever arm. The lever arm may be comprised of side arms attached to the mounting wall, and an upper arm spanning across the top wall. The lever arm may snap in place behind the cantilever beam when in the fully mated position. The engageable lugs and the lever arm may be profiled as rack and pinion teeth.
[0010] An inventive method of manufacturing an electrical connector assembly, comprises the steps of providing a first connector housing having a first exterior profile, where the exterior profile has at least one engageable lug positioned adjacent to a leading edge of the first connector housing. The first connector housing is provided with at least one first contact member therein. A second connector housing is provided having a second exterior profile profiled for overlappingly receiving, the first exterior profile. The second connecting housing has at least one second contact member therein, for mate able connection with the first contact member. A channel is provided on the second connector housing to receive the at least one engageable lug. A mounting wall is provided on the connector housing for an optional mating assist member. The method also includes selectively determining if a mating assist member is required on the basis of the anticipated mating force between the first and second connector housings, and if selected, mounting a mating assist member on the mounting wall in position for engagement with the at least one engageable lug.
[0011] The first latch member may be profiled as a cantilever beam extending rearwardly away from the leading edge. The second latch member may be comprised of a raised wall. The cantilever beam of the first latch member is receivable into an area beneath the raised wall. The first and second latch members may include first and second cooperating latching projections. The first latching projection may project upwardly from the cantilever beam, and the second latching projection may project downwardly from the raised wall. The pair of engageable lugs may be positioned on side walls of the first connector housing, and the first latch may extend from a top wall.
[0012] The mating assist member may be a lever arm, comprised of side arms attached to the mounting wall, and an upper arm spanning across the top wall. The lever arm may snap in place behind the cantilever beam when in the fully mated position. The engageable lugs and the lever arm may be profiled as rack and pinion teeth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view showing the connector assembly in a mated condition;
[0014] FIG. 2 is an underside perspective view of FIG. 1 ;
[0015] FIG. 3 shows an exploded view of the entire plug assembly of the embodiment of FIG. 1 ;
[0016] FIG. 4 shows an exploded view of the lever-assist plug housing in greater detail;
[0017] FIGS. 5 and 6 show alternative perspective views of the mating assist lever shown in FIG. 4 ;
[0018] FIG. 7 shows a cross-sectional view through FIGS. 7-7 of FIG. 6 ;
[0019] FIG. 8 shows the assembled view of the components of FIG. 4 ;
[0020] FIG. 9 shows an exploded view of the header or male connector, also shown in FIG. 1 ;
[0021] FIG. 10 shows an enlarged view of the housing portion of FIG. 9 ;
[0022] FIG. 11 shows the header assembly or male half of the connector from the opposite perspective as FIG. 10 shows the housing only;
[0023] FIG. 12 shows a view showing the connectors of FIGS. 8 and 10 poised for interconnection;
[0024] FIG. 13 shows a cross-sectional view through lines 13 - 13 of FIG. 1 ;
[0025] FIG. 14 shows the connectors of FIG. 13 in the initial disconnection state;
[0026] FIG. 15 is an enlarged view of the encircled portion on FIG. 14 ;
[0027] FIG. 16 is a cross-sectional view similar to that of FIG. 14 showing the connectors in a further disconnection state;
[0028] FIG. 17 shows an enlarged view of the encircled portion on FIG. 16 ;
[0029] FIG. 18 shows an alternative plug housing, where the mating assist lever is not required; and
[0030] FIG. 19 shows an alternative plug housing having no mating assist lever required.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] With respect first to FIGS. 1 and 2 , an electrical connector assembly is shown as 2 , which comprises a plug connector assembly 4 with a mating assist member 6 , shown here as a lever or lever arm, interconnected to a header connector assembly shown at 8 . The two connector assemblies 4 , 8 are held together by a latch assembly shown generally at 10 and which will be described in greater detail herein.
[0032] With respect now to FIG. 3 , the plug or female connector assembly 4 is shown in an exploded manner, where mating assist member 6 is exploded away from its associated connector housing 20 , and where a rear wire seal 22 and rear cover 24 are also shown together with contacts or terminals 26 and 28 . On the front side of the connector housing 20 , a front seal 30 and a terminal position assurance member 32 are shown exploded from the front side of connector housing 20 .
[0033] With reference now to FIG. 4 , connector housing 20 and mating assist member 6 are shown exploded from each other, and connector housing 20 is shown in greater detail. Housing 20 generally includes an exterior profile defined by an outer shroud 34 , which includes alignment channels 36 , and further includes a central raised wall at 38 . This central raised wall 38 includes a central notch at 40 , with a latching mechanism in the form of locking projections 42 (only one of which can be viewed in FIG. 4 ) extending downwardly from the central raised wall 38 along the perimeter of notch 40 , as will be further described herein. Raised wall 38 is spaced above an inner wall 46 , and defines an opening therebetween for receipt of a mating latch as will also be described in greater detail herein.
[0034] With respect still to FIG. 4 , connector housing 20 further includes a pair of mounting walls 50 connected to the connector housing 20 by side walls 52 , separating mounting walls 50 from an inner portion of housing 20 and defining channels 54 therein. Mounting walls 50 further include mounting slots shown generally at 56 , each including a narrowed passageway 58 opening into an enlarged circular bearing 60 .
[0035] The connector housing 20 also includes a conventional internal housing portion at 64 having a plurality of terminal cavities, such as 66 , for smaller electrical terminals and enlarged cavities at 68 , for larger current carrying capacity electrical terminals.
[0036] With respect now to FIGS. 5 through 7 , mating assist member 6 is comprised of an upper arm at 70 having side arms at 72 . Upper arm 70 includes a notched portion at 74 , which includes a first latching projection at 76 , positioned at a trailing edge of the upper arm 70 . As best shown in FIGS. 5 and 7 , mating assist member 6 further includes at least one contoured surface to assist in releasing the latch assembly 10 , shown here as two release projections 78 in FIGS. 6 and 7 . With respect to FIGS. 5 and 6 , mating assist member 6 further includes an axle portion at 80 including parallel and opposed flat surfaces 82 , with upper and lower circular portions at 84 .
[0037] With respect now to FIGS. 5 and 7 , the mating assist member 6 further includes a pinion portion 90 having drive teeth 92 and 94 . As shown in FIGS. 5 through 7 , mating assist member 6 further includes an arcuate arm portion 100 connected to the side arms 72 via an arm portion 102 , as best shown in FIG. 7 . Arcuate arm portion 100 is spaced away somewhat from side walls 72 and positioned above axle portion 80 so as to cause an entry opening at 106 , as best seen in FIG. 5 . Arcuate arm portion 100 includes an inner contact surface at 108 , as will be described in further detail.
[0038] It should be appreciated that the axle portions 80 are profiled such that the flat surfaces 82 can be positioned between the narrowed passageways 58 ( FIG. 4 ) with the circular portions 84 being rotatable within the enlarged circular bearing 60 ( FIG. 4 ). With respect now to FIG. 8 , connector housing 20 is shown with mating assist member 6 installed and rotated to an open position, whereby pinion tooth 92 is positioned within the channel 54 in an assist position and poised for interconnection with a mating connector, as will be described in greater detail herein.
[0039] With respect now to FIG. 9 , header connector assembly 8 is shown in an exploded manner as including a housing portion 120 , a terminal position assurance member (TPA) 122 , a discrete wire seal 124 , contacts or terminals 126 and 128 , and rear cap 130 . As shown in FIGS. 10 and 11 , housing 120 includes a front end 140 , and a rear wire-receiving end 142 . Front end 140 includes a shrouded portion at 144 , which is profiled to mate with the plug connector housing 20 with alignment ribs 146 positionable with alignment channels 36 ( FIG. 4 ).
[0040] Housing 120 further includes a latch member 150 , as a component of latch assembly 10 , which includes a cantilever beam portion 152 integrally connected to a top wall 154 by a web portion 156 , and extends rearwardly of the housing 120 . As shown best in FIG. 10 , cantilever beam portion 152 includes side wall sections 160 having locking projections 162 upstanding therefrom. Two side wall sections 164 flank the cantilever beam portion 152 and include overstress members 166 . As shown in FIG. 10 , the extreme end of cantilever beam portion 152 includes an angled edge portion 170 , which defines a contacting surface, whereas the top of the latch cantilever beam portion 152 includes two contact surfaces at 172 .
[0041] Finally, as shown in either of FIGS. 10 or 11 , housing 120 includes a portion 180 which provides an engagement lug, in the form of a simulated gear rack including a first tooth 182 , positioned on side wall 184 . Housing 120 further includes alignment bars 190 having a locking extension at 192 , again as will be described further herein.
[0042] With both connector assemblies 4 , 8 as described herein, the operation of the connector housings 20 and 120 will be described herein. As shown in FIG. 12 , the two connector housings are mate able with the alignment ribs 146 aligning with the alignment channels 36 , which positions locking extensions 192 in position in openings 106 ( FIG. 6 ) of the mating assist member 6 , and which positions rack tooth 182 in position to be received below pinion tooth 92 . Thus, rotation of the mating assist member 6 in the counterclockwise sense (as viewed in FIG. 12 ) causes the engagement of the rack and pinion teeth 182 , 92 causing the connectors to move into an interconnected state. At the same time, arcuate arm portions 100 rotate to entrap extensions 192 .
[0043] When the connectors are fully engaged, the connector pair is in the position of FIG. 1 , and locking projections 162 are positioned behind locking projections 42 . This also positions angled edge surface 170 in a close proximity to corresponding latching projection 76 on pivot-assist member as shown in FIG. 13 . These two corresponding surfaces prevent disengagement between the two, as a counter-rotation of mating assist member 6 (that is in the clockwise position as viewed in FIG. 13 ) would cause the abutment of the latching projection 76 and edge surface 170 lifting latch member 150 into the overstress members 166 ( FIG. 10 ).
[0044] At the same time, projections 78 assist in holding the latch member 150 down during the counter-rotation, allowing mating assist member 6 to be rotated without having to hold down latch member 150 by hand. With respect first to FIGS. 14 and 15 , when the latch is initially depressed and the mating assist member 6 has begun a counter-rotation, in the counterclockwise sense as viewed in FIGS. 14 and 15 , projections 78 have contoured surfaces which begin to ride up on surface 172 , which holds the latch in the downward position such that locking projections 42 and 162 are clear of each other, as best shown in FIG. 15 . Continued rotation of the mating assist member 6 , to the position now shown in FIGS. 16 and 17 , positions projection 78 further along on surface 172 and locking projection 162 has now cleared beneath locking projection 42 , preventing snagging between the two connectors.
[0045] As mentioned above, depending upon the mating force between the two connectors (as a result of the number of terminals loaded), it is possible to have a connection pair that does not require the mating assist member 6 , and two embodiments of the modified connection system are shown in FIGS. 18 and 19 .
[0046] With respect first to FIG. 18 , it is possible to have a connector housing, such as 204 , which simply eliminates the mating assist member 6 leaving a mounting slot at 256 identical in nature to mounting slots 56 described above. In this configuration, the two connectors are simply connected together by hand, whereby the latch assembly 210 holds the two connectors together.
[0047] As shown in FIG. 19 , a revised housing is shown at 304 having solid outer walls at 350 , which eliminates any of the mounting slots 56 or 256 . This is accomplished by simply eliminating the mold tooling, which forms the passageways 58 and circular bearing 60 of the embodiment shown in FIG. 4 . This housing would work in almost identical nature to that shown in FIG. 18 , whereby the two connectors are simply brought into engagement with each other and into a latched condition, as described above.
[0048] Advantageously, the connector assembly can easily accommodate multiple configurations for various numbers of terminals loaded in the connection system. As mentioned above, depending on the number of terminals loaded in the various connector assemblies, the mating forces between them may be above or below the USCAR 75 Newton threshold, which may require or not require the mating assist member 6 . Thus, the design can easily accommodate either having or not having the lever-assist member by either simply eliminating it as in the FIG. 18 embodiment or by simply removing the side mold tooling as in the FIG. 19 embodiment. Other advantages are shown in our patent application, Attorney Docket Number E-AV-00073, Ser. No. ______, concurrently filed and incorporated herein by reference. | A connection system is shown where a lever-assist member may be added to assist in the mating between two connector housings as is needed depending upon a number of connector terminals loaded and the mating force between them. The lever-assist member is also locked in place by the interaction of the pivot-assist member and the corresponding latching structure of the connectors. The lever-assist member, when moved into the disconnection condition, has a projection which holds the cantilever beam arm of the latch in a position allowing the two connectors to be disconnected, which does not require the user to continue depressing the latch at the same time as rotating the pivot-assist member. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a system for cancelling offsets in amplifiers. The invention is particularly useful for conditioning a transducer signal.
In Digital Versatile Disc (DVD) and Compact Disc-Read Only Memory (CD-ROM), a photodetector is used for reading information from a disc. The photodetector output current is typically amplified by an amplifier before it is sent to the next stage. "Amplifier offset" is defined as the difference between the DC level of the amplifier output and a reference voltage when no signal (from the photodetector) is applied to the amplifier. Due to the "unipolar" characteristics of the photodetector output current, conventional auto-zeroing circuit may not be used to optimize the amplified output. In existing systems, the amplifier offset is optimized during the wafer sort stage in integrated circuit fabrication by means of a trimming scheme. The integrated circuits for the DVD/CD-ROM systems employ polysilicon or metal fuses. The DC level of the amplifier outputs in such systems are set by applying a high trimming current to burn one or more fuses.
Thus, in a conventional trimming scheme for cancelling the amplifier offset, the cancellation may only be performed once, since after the optimization by burning one or more fuses, the DC level of the amplifier output can no longer be changed. Since different operating conditions may result in different amplifier output DC levels, the above-described conventional trimming scheme is quite limited, since the DC level of the amplifier output cannot be changed with the operating conditions. Thus, the operating conditions may change as a function of the gain setting of the amplifier, the condition of the power supply voltage and temperature, as well as backward or forward compatibility to other devices downstream or upstream in the signal path from the amplifier.
The requirement of the trimming step during the wafer sort stage will add additional testing costs due to the extra testing time required. Moreover, the application of a high trimming current to burn a fuse may, in some situations, affect product reliability. It is, therefore, desirable to provide an improved system for offset optimization where the above-described drawbacks are alleviated or eliminated.
SUMMARY OF THE INVENTION
One aspect of the invention is directed towards an apparatus for cancelling offsets in amplifiers, comprising a comparator comparing an output of at least one amplifier to a reference, where no external signal is applied to the at least one amplifier, to provide an output; and means responsive to the comparator output for generating a correction signal applied to the at least one amplifier to adjust DC level of the output of the at least one amplifier until the DC level is essentially equal to the reference.
Another aspect of the invention is directed towards a method for cancelling offsets in amplifiers, comprising comparing an output of at least one amplifier to a reference, where no external signal is applied to the at least one amplifier, to provide a comparison output; and generating, in response to the comparison output, a correction signal and applying the correction signal to the at least one amplifier to adjust the DC level of the output of the at least one amplifier until the DC level is substantially equal to the reference.
One more aspect of the invention is directed towards an apparatus for conditioning a transducer signal, comprising at least one amplifier for conditioning the transducer signal, said at least one amplifier having an output; comparator means for comparing the output of the at least one amplifier to a reference, where no external signal is applied to the at least one amplifier, to provide an output; and means responsive to the comparator output for generating a correction signal and applying it to the at least one amplifier to adjust the DC level of the output of the at least one amplifier until the DC level is substantially equal to the reference.
Yet another aspect of the invention is directed towards a method for conditioning a transducer signal, comprising comparing an output of at least one amplifier to a reference, when no external signal is applied to the at least one amplifier, to provide a comparison output; generating, in response to the comparison output, a correction signal and applying the correction signal to the at least one amplifier to adjust the DC level of the output of the at least one amplifier until the DC level is substantially equal to the reference; and amplifying the transducer signal by means of said at least one amplifier.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system for cancelling offsets in amplifiers to illustrate the preferred embodiment of the invention.
FIGS. 2-6 are flow charts illustrating the operation of the state machine in the system of FIG. 1 to illustrate the preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a block diagram of a system for cancelling offsets of transimpedence amplifiers for six channels to illustrate the preferred embodiment of the invention. In each of the six channels (A, B, C, D, E, F), a corresponding photodetector, such as photodetector PD-A for channel A, provides a current to a transimpedence amplifier core 12 also having six channels to be amplified, before the amplified output O A for channel A is provided to the next stage of the system (not shown). Similarly, amplifier core 12 amplifies the output of the other five photodetectors PD-B through PD-F and provides, together with O A , a total of six outputs (O A , O B , . . . O F ).
The DC level of the output of amplifier core 12 for each of the six channels may change depending on the gain setting, power supply voltage applied to amplifier core 12 from power terminal 14, temperature and other factors. Also, for backward compatibility with existing compact disc-audio, CD-ROM, CD-R, and CD-RW as well as forward compatibility with DVD-RAM, it is desirable to be able to adjust the DC level of the output of amplifier core 12 for each of the six channels on an as needed basis, or periodically. This is not possible with the conventional technique of trimming, which can only be performed once, after which the DC level of the amplifier output can no longer be changed.
For this purpose, the six outputs O A , . . . O F are selected by an analog multiplexer 16, one at a time, for comparison by comparator 18. Comparator 18 compares each of the six selected outputs of amplifier core 12 to a voltage reference VREF, when the photodetector is applying no signal to the core 12, so that the output of each of the channels is a DC level. Comparator 18 then supplies a comparison output signal to state machine 20. For example, the comparator compares output O A to the voltage reference. In response to the comparison output or signal, state machine 20 provides an output, which in the preferred embodiment is a five bit binary output, to a corresponding set among six sets of latches 22, where each set includes 5 latches, each latch storing one bit. Such corresponding set of latches (corresponding to output O A ) stores the 5 bit state machine output for adjusting the DC level of the amplifier core output to yield output O A . The stored value is converted by one of six corresponding digital to analog converters 24 into an analog signal and this analog signal is applied to transimpedence amplifier core 12 for adjusting the DC level of the output of the particular channel amplifier core that gives output O A . The above process is applied when the photodetector PD-A (or any other device external to the offset cancellation apparatus) of the channel A is not applying any signals to the amplifier core 12 for such channel, so that the difference between the reference value VREF and the output (a DC level) of the amplifier core 12 for such channel is the offset. After the offset adjustment, the amplifier core for such channel would provide a new output O A '. The new output O A ' of amplifier core 12 for such channel is again compared by comparator 18 to the voltage reference and the updated comparison output of comparator 18 is used by state machine 20 to provide an updated output for further adjustment of the DC level of the output of the amplifier core 12 for such channel to provide yet another updated output. This process is repeated until the DC level of the output of the amplifier core for such channel is substantially the same as the voltage reference VREF, at which point the state machine applies a next channel calibration signal along path 32 to analog multiplexer 16, causing the multiplexer to select a different output channel of amplifier core 12 than channel A for calibration.
The above-described process is then carried out for the remaining five channels so that offsets are adjusted until the DC levels of the outputs of all of the six channels in amplifier core 12 are substantially equal to the voltage reference VREF.
The state machine 20 is operated by means of a reference clock from an oscillator 34. After the DC level of the outputs of all channels in amplifier core 12 have been calibrated as described above, state machine 20 sends an end of calibration signal to oscillator 34, causing oscillator 34 to go into a "sleep mode." By shutting off the oscillator after the completion of the autocalibration process, any reference clock related glitch and/or noise will be eliminated and the performance of the low noise transimpedence amplifier 12 will be enhanced.
System 10 may form a part of a typical DVD/CD-ROM head amplifier. When power is first turned on to such typical head amplifier, system 10 will initiate a calibration process for adjusting the offsets of amplifier core 12. However, when power is first turned on, the voltage level applied may be unsteady. If the above-described autocalibration process is carried out when the power supply voltage is still fluctuating, or not at the right voltage, the calibration results may be invalid. To prevent this from happening, an under voltage lock out circuit 42 is employed which senses the power supplied to amplifier core 12. If the voltage level at terminal 14 is still unsteady or at the wrong voltage level, circuit 42 will not generate an enable signal to enable oscillator 34. But if circuit 42 senses that the voltage at terminal 14 is at the proper level or state, circuit 42 will generate an enable signal through logic 44 to oscillator 34, causing oscillator 34 to generate a reference clock for state machine 20, thereby causing state machine 20 to start to operate.
The gain of the amplifier core 12 may be altered after the DVD/CD-ROM head amplifier has been operating. Even if the DC levels of the outputs for the different channels of amplifier core 12 were at the proper values prior to the gain change, after the change in gain, the DC level of the outputs of these channels may be off from desired values, so that it is desirable to repeat the calibration process after an alteration in gain of the amplifier core 12. For this purpose, an autosense circuit 52 senses a change in the gain at terminals 54, 56, 58. When circuit 52 senses that there is a change in gain, it applies an enable signal through logic 44 to oscillator 34, causing the oscillator to generate a reference clock to initiate the operation of the state machine 20. State machine 20 will then operate in the manner described above in conjunction with multiplexer 16, comparator 18, latches 22 and converters 24 to perform the autocalibration as described above. The construction of the under voltage lockout circuit 42 and of the autosense circuit 52 may be of conventional design and will not be described in detail here. Logic 44 may simply be an OR-gate.
In the preferred embodiment, state machine 20 is used to more accurately calibrate the DC levels of the output of the different channels in amplifier core 12; it will be understood that other circuits may be used instead and are within the scope of the invention.
The operation of state machine 20 in the calibration process will now be described in reference to FIGS. 2-6. State machine 20 operates by a process of successive approximation. In reference to FIG. 2, state machine 20 detects whether the comparator 18 output is positive or negative. A positive comparator output indicates that the DC level output (referred to below simply as "output") of the particular amplifier channel being calibrated is lower than VREF so that it should be increased whereas a negative comparator output indicates that the output of the particular amplifier channel being calibrated is at a higher voltage level compared to VREF so that it should be lowered. First the state machine 20 is reset to all zeros.
In the preferred embodiment illustrated in FIGS. 2-6, the state machine 20 has a six bits resolution. Thus, all six bits of the state machine are initially reset to "0" as shown in block 102. The statuses of the bits of state machine 20 are indicated within the ellipses in FIGS. 2-6, where the hexadecimal equivalent state of such binary states are indicated immediately on top of the corresponding ellipse. Thus, as shown in and near ellipse 102, the initial state of the state machine 20 is all zeros, or 00H in hexadecimal. If the comparator output is positive, the most significant bit is set to a "1", indicating that the amplifier core output for the channel needs to be increased; whereas if the output of the comparator is negative, indicating that such output needs to be decreased, a "0" is indicated for the most significant bit (MSB). Therefore, even though initially and temporarily, the MSB is set to a "1" in ellipse 104, a detection of the comparator output will cause the MSB to be changed to "0" if the comparator output is negative and to remain "1" if the comparator output is positive.
For the purpose of illustration, it is assumed that the output of a particular channel of amplifier core 12 being calibrated is at 1.8 volts whereas VREF is at 2.5 volts. Thus, the comparator output will be positive and the MSB will remain a "1." State machine 20 proceeds to ellipse 106 and automatically sets the next or second MSB bit to a "1" as shown in ellipse 106. The state machine now must test to see if the next or the second MSB bit should be a "1" or a "0." For this purpose, the state machine sends five bits, that is all six bits except for the MSB, to the corresponding latches 22. In other words, in the particular example here, the binary value "10000" is sent to latches 22. This digital value is then converted by convertor 24 into an analog voltage value and applied to the particular channel being calibrated in amplifier core 12. Convertor 24 may be controlled to select the proper voltage steps. In this example, it is assumed that a binary value of "10000" is converted to 0.5 volts by the convertor, and this step would apply a 0.5 volt adjustment. Thus a "10000" binary value translates into adding a 0.5 volts to the output, resulting in an output of the channel of 2.3 volts.
Such 2.3 volts output passes through multiplexer 16 to comparator 18 which detects that such output is still lower than VREF of 2.5 volts. This confirms the correctness of adding the 0.5 volts in ellipse 106 so that the "1" value of the next or second most significant bit is retained and the state machine proceeds to ellipse 108 to set the next or third most significant bit to a "1", so that ellipse 108 now contains "111000." The output of state machine 20 is therefore "11000" which is applied to latches 22. This latched binary value translates to a 0.75 volts and the convertor 24 adds a 0.75 volts adjustment to the output of 1.8 volts of the channel being calibrated, resulting in a 2.55 volts output. Comparator 18 detects that such output would be greater than VREF of 2.5 volts, so that the third most significant bit of the state machine 20 is changed from a "1" to a "0". This is shown in FIG. 5 where the state machine 20 then proceeds to ellipse 110 and the next or the fourth most significant bit is set to a "1", so that ellipse 110 now contains the value "1 10100" and the binary value "10100" is applied to latches 22. This value is converted by convertor 24 to 0.625 volts which is added to the 1.8 volt output of the channel calibrated, resulting in an output of 2.425 volts which is less than VREF. This means that the fourth most significant bit should retain the value "1" and state machine 20 proceeds to ellipse 112 and so on until all six bits of the state machine are determined. At this point, the DC level of the output of the channel being calibrated has been adjusted to be as close to VREF as permitted by the resolution of the state machine.
The state machine then causes the multiplexer 16 to select another channel for calibration unless all the channels have been calibrated. Thus, the latches corresponding to the channel just calibrated will store the value arrived at by the state machine which in turn, causes convertor 24 to apply the appropriate voltage correction to the channel being calibrated in order to adjust the output to the desired value VREF. In this manner, the six sets of latches and the six converters together apply the desired voltage corrections to their corresponding amplifier channels so that these channels have minimal offsets.
While in the preferred embodiment, state machine 20 employs six bits, it will be understood that state machine 20 may employ more bits for a more accurate offset adjustment or fewer bits to speed up the calibration process; such and other variations are within the scope of the invention. The conversion of the digital values to analog voltages may be selected to be different from the example used above; such variations are within the scope of the invention.
While the embodiment above has been illustrated in reference to an amplifier core and corresponding digital to analog convertors and six sets of latches for six channels, it will be understood that any number of channels may be employed and are within the scope of the invention. While in the embodiment described, the amplifier core 12 is used for amplifying signals from photodetectors for devices such as DVD and CD-ROM, it will be understood that the amplifier core 12 may be used for applying signals from magnetic heads in hard disk drives, or from other transducers, such as those in other mass storage systems and communication systems. In such event, the photodetectors in FIG. 1 would be simply replaced by magnetic heads or other transducers; in such cases, no signals are applied by external devices such as these heads or transducers during the calibration process. Amplifier core 12 in the above embodiment converts current to a voltage. It will be understood that the same calibration scheme may be applied to amplifiers which convert voltage to voltage, voltage to current or current to current as well.
While the invention has been described by reference to preferred embodiments, it will be understood that various changes and modifications may be made without departing from the scope of the invention which is to be defined only by the appended claims and their equivalents. | The DC level of the output of an amplifier may be dynamically adjusted depending on the operating conditions of the amplifier by comparing the output of the amplifier to a set reference value using a comparator. The output of the comparator is then fed to a state machine which adjusts the DC level of the amplifier output in an autocalibration process until the DC level of the output of the amplifier is substantially equal to the reference value. An undervoltage lockout circuit detects a power supply to the amplifier and causes the calibration to be initiated only when the power supply meets certain requirements. A change in the gain setting in the amplifier is also detected for automatically initiating the calibration process. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a storage system, and more particularly to a change in the allocation of a real storage area to a virtual volume in a storage system having a virtualization apparatus of a redundant configuration.
2. Description of the Prior Arts
In the so-called SAN (Storage Area Network), a system that sets a plurality of virtual volumes with reference to the storage area of a storage device and uses their volumes from a host processor via a network is known.
Regarding a storage virtualization apparatus that virtualizes the storage device connected through the network and enables input-output (I/O) from the host processor, for example, there is such a system as disclosed in Japanese Unexamined Patent Application Publication No. Hei 2000-242434 (Patent Reference 1). According to this art, a storage device to which a virtual storage area provided to a host is allocated is changed by installing switching equipment 20 between a storage device system 1 and a host 30 and the switching equipment 20 changes the virtualization setting of a virtual storage device system provided to the host 30, thereby to change the storage device to which a virtual storage area to be provided to a host is allocated.
The configuration information about the storage virtualization apparatus (for example, array disk switch) group described in Patent Reference 1 is managed independently for each storage virtualization apparatus.
In such a storage virtualization system, the modification of the configuration information during system operation changes the destination during input-output processing and causes data corruption and an input-output fault. Accordingly, a method for reducing the storage virtualization apparatuses that operate concurrently during a configuration change to only one apparatus can be considered, but a problem that concentration of a load or fault tolerance decreases is arisen. The aforementioned Patent Reference 1 does not refer to the modification of configuration information indicating that one volume shifts to another volume while the storage device system is operating.
SUMMARY OF THE INVENTION
An object of the present invention is to prevent data corruption and an input-output fault during system operation and change the configuration information about a storage virtualization apparatus in a storage system having a virtualization apparatus of redundant configuration.
The present invention is constructed in a plurality of virtualization apparatuses that process input-output to/from a host processor to a virtual volume on the condition that a request for temporarily holding the input-output processing accepted from the host processor after a certain point of time is issued to the plurality of virtualization apparatuses and a report indicating that the ongoing input-output processing was completed in regard to this request was received from each virtualization apparatus. On the condition, the present invention releases an input-output state held temporarily after having changed the allocation of the storage area of a storage device to each virtualization apparatus and having accepted a completion report of the allocation change from each virtualization apparatus.
As a desirable example concerning a storage system, the storage system having a storage device that can specify a plurality of storage areas and a plurality of virtualization apparatuses that allocate a storage area which this storage device has, form a plurality of virtual volumes, process the input-output from a host processor to one of the virtual volumes, and includes a configuration change controller for changing an allocation configuration of storage area of the storage device to the virtual volume. The configuration change controller has a means for requesting a temporary hold of the input-output to all the virtualization apparatuses before a configuration change and a means for allowing all the virtualization apparatuses that received this request to complete the input-output being processed and to subsequently shift to a state of temporarily holding an input-output request from the host processor subsequently, then to return a completion report to the configuration change controller. The configuration change controller has, when receiving the completion report from the previous plural virtualization apparatuses to which a request was issued, a means for instructing an allocation change of the storage area of the storage device to the virtual volume to the virtualization apparatus.
Further, as a desirable example regarding a plurality of virtualization apparatuses, they have a configuration change control program for changing a configuration of associating a virtual volume with a storage area that becomes a real area of the storage device and a first processor that executes the configuration change control program. This configuration change control program has, before changing the configuration of associating the virtual volume with the storage area that becomes the real area of the storage device, a means for requesting an input-output temporary hold to another virtualization apparatus. The other virtualization apparatus that received the request has a means for completing the input-output being processed and subsequently shifting to a state of temporarily holding an input-output request from a host processor, and returning a completion report. The configuration change control program has, when receiving the completion report from the other virtualization apparatus, a means for instructing an allocation change of the storage area of the storage device to the virtual volume to the other virtualization apparatuses, a means for receiving the completion report of the allocation change from another virtualization apparatus, and a means for sending an instruction for releasing the state of the input-output held temporarily to the other virtualization apparatus.
Furthermore, as an example of the configuration concerning a storage device, the storage device has a plurality of storage areas for providing a real storage area and a virtualization apparatus that allocates the plurality of storage areas, forms a plurality of virtual volumes, and processes the input-output from a host processor to one of the virtual volumes. This virtualization apparatus has, before changing a configuration of associating the virtual volume with the storage area that becomes a real area of the storage device, a means for requesting an input-output temporarily hold to another virtualization apparatus. The other virtualization apparatus that received the request has a means for completing the input-output being processed and subsequently shifting to a state of temporarily holding an input-output request from the host processor, and returning a completion report. The virtualization apparatus has, when receiving th completion report from the other virtualization apparatus, a means for instructing an allocation change of the storage area in regard to the virtual volume to the other virtualization apparatus, a means for receiving the completion report of the allocation change from the other virtualization apparatus, and a means for sending an instruction for releasing the state of the input-output held temporarily to the other virtualization apparatus.
As a more desirable example, data can migrate from one storage device to another storage device during system operation by copying the data between the storage devices synchronizing with the change of configuration information. Moreover, even a virtualization apparatus not having a copy function can migrate data by allowing the storage device to implement a configuration change control function and the aforementioned copy processing function.
According to the present invention, the configuration information of a virtual volume can be changed during system operation by preventing as much influence of an input-output temporary hold as possible. Consequently, data can migrate from one storage device to another storage device during system operation. Moreover, even a virtualization apparatus not having th copy function can shift data. A storage device that can change an allocation destination of the virtual volume can be realized during operation in a redundant configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will be described in detail based on the followings, wherein:
FIG. 1 is a drawing showing the overall configuration of a storage system according to a first embodiment;
FIG. 2 is a drawing showing the internal configuration of a virtualization switch 11 of FIG. 1 ;
FIG. 3 is a drawing showing the internal configuration of a configuration change controller 16 of FIG. 1 ;
FIG. 4 is a drawing showing the table of a configuration information 221 in the storage system;
FIG. 5 is a drawing showing the communication protocol between a configuration change controller 16 and a virtualization switch 11 in the storage system of FIG. 1 ;
FIG. 6 is a flowchart showing the processing of a configuration change control program 212 in a configuration change controller 16 ;
FIG. 7 is a flowchart showing the processing of a configuration management program 211 in a virtualization switch 11 ;
FIG. 8 is a flowchart showing processing of an I/O processing program 213 in the virtualization switch 11 ;
FIG. 9 is a drawing showing the internal configuration of the virtualization switch 11 according to a second embodiment;
FIG. 10 is a flowchart showing the processing of a configuration change control program 212 in the second embodiment;
FIG. 11 is a flowchart showing the processing operation of arbitration processing 600 in FIG. 10 ;
FIG. 12 is a drawing showing the internal processing of the virtualization switch 11 according to a third embodiment;
FIG. 13 is a drawing showing the communication protocol between the configuration change controller 16 and the virtualization switch 11 in the third embodiment;
FIG. 14 is a drawing showing an example of a temporary hold control table 223 in FIG. 12 ;
FIG. 15 is a drawing showing the table of the configuration information 221 in FIG. 12 ;
FIG. 16 is a flowchart showing the processing of the configuration management program 212 in FIG. 12 ;
FIG. 17 is a flowchart showing the processing of the configuration management program 211 in FIG. 12 ;
FIG. 18 is a flowchart showing the processing of the I/O processing program 213 in FIG. 12 ;
FIG. 19 is a drawing showing the internal processing of the virtualization switch 11 in a fourth embodiment;
FIG. 20 is a drawing showing the table of the configuration information 221 in FIG. 19 ;
FIG. 21 is a flowchart showing the processing of the configuration change control program 212 in FIG. 19 ;
FIG. 22 is a flowchart showing the details of copy processing 631 in the flowchart of FIG. 21 ;
FIG. 23 is a flowchart showing the processing of the configuration management program 211 in FIG. 19 ;
FIG. 24 is a flowchart showing the processing of the I/O processing program 213 in FIG. 19 ;
FIG. 25 is a flowchart showing the processing of a copy processing program 214 in FIG. 19 ;
FIG. 26 is a drawing for describing an operation principle of data migration in the fourth embodiment;
FIG. 27 is a drawing showing the overall configuration of the storage system in a fifth embodiment;
FIG. 28 is a flowchart showing the processing of the configuration change control program 212 in the fifth embodiment; and
FIG. 29 is a drawing showing the overall configuration of the storage system in a sixth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Embodiments of the present invention will be described below with reference to the drawings.
First, a first embodiment is described with reference to FIGS. 1 to 8 .
FIG. 1 is a drawing showing the overall configuration of a storage system.
The storage system connects at least one host processor 12 , a plurality of storage devices 13 , a plurality of virtualization switches 11 , a configuration change controller 16 , and a management console 14 to a network 15 such as a LAN.
The host processor 12 is a computer that uses data stored in the storage device 13 . The host processor 12 may be a file server having a function provided to another computer that does not connect a storage area which the virtualization switch 11 provides to the virtualization switch 11 .
The storage device 13 is provided with a memory unit 13 a or a memory unit system 13 b . In this case, the memory unit 13 a is a single memory unit such as a hard disk drive or a DVD drive. The memory unit system 13 b is a storage subsystem having the plural memory units 13 a and a controller 1301 that controls these memory units. A memory unit 131 constructs the storage area of the memory unit 13 a as a logical unit (hereafter referred to as an “LU”) 131 . The LU 131 is a logical storage area, and the device connected to the storage device 13 such as the host processor 12 , is recognized as one logically independent storage device.
Further, the logical unit 131 is provided with a plurality of partly logical storage areas (hereafter referred to as “real areas”) 132 . Each of the real areas 132 corresponds to a physical storage area which the storage device 13 has. The size of the real area 132 is arbitrary and the rang is an area having a continuous address.
The virtualization switch 11 is connected to another device through a communication line or by a switch as shown in the drawing and can communicate with another device. Further, the virtualization switch 11 is a virtualization apparatus that collects (“virtualizes”) the storage areas which the plural storage devices 13 connected to the virtualization switch 11 itself has as one or more storage areas. Then the virtualization switch 11 provides a virtualized storage area to the host processor 12 connected to the virtualization switch 11 . The virtual storage area which the virtualization switch 11 provides to the host processor 12 is hereafter referred to as a virtual volume 100 .
A protocol such as a fibre channel, is used in the communication line or switch used between the virtualization switch 11 and the host processor 12 and between the virtualization switch 11 and the storage device 13 . In this case, the communication line or switch used may be the communication line or protocol used in a local area network. The virtualization switch 11 is connected between the host processor 12 and the storage device 13 and has a function of transferring a command the host processor 12 issues to the side of th storage device 13 .
The virtual volume 100 is a virtualized storage area having at last the one real area 132 . The virtualization switch 11 can provide at least one virtual volume 100 to the host processor 12 . A unique identifier (hereafter referred to as a “virtual volume identifier”) is assigned to each virtual volume 100 in the virtualization switch 11 for specifying a virtual volume. Moreover, a continuous address is assigned to the storage area of each virtual volume 100 . The host processor 12 specifies an address indicating a virtual volume identifier and a location in the virtual volume 100 and accesses data stored in the storage device 13 instead of directly specifying the real area 132 within the LU 131 of the storage device 13 .
The management console 14 is such a personal computer (PC) that is used by a system administrator to create the virtual volume 100 and has a display device or an input device, and a memory. The management console 14 is connected to the virtualization switch 11 via the LAN 15 and can communicate with each other.
The configuration change controller 16 controls the virtualization switch 11 and controls configuration information, that is, the change of associating the virtual volume 100 with the real area 132 . The configuration change controller 16 can have a PC or a server, for example, and is connected to the virtualization switch 11 via the LAN 15 , which can communicate with each other.
FIG. 2 shows the internal configuration of the virtualization switch 11 of FIG. 1 .
The virtualization switch 11 is provided with an input port 240 , an output port 250 , a transfer unit 230 , a processor 210 , a memory 220 , a bus 270 , and a communication unit 260 . The transfer unit 230 , processor 210 , memory 220 , and communication unit 260 are all connected to the bus 270 , and send and receive data to/from each other.
The input port 240 connects a communication line through which the virtualization switch 11 communicates with the host processor 12 . The output port 250 connects a communication line through which the virtualization switch 11 communicates with the storage device 13 . Further, the element constructing the input port 240 and the output port 250 may be located in the same hardware. In this case, the user selects which port is used as the input port or the output port.
The transfer unit 230 has an internal memory and holds a transfer information table 231 in the memory. The transfer information table 231 stores the interrelationship between the host processor 12 that can communicate with the virtualization switch 11 via each input port 240 and the storage device 13 that can communicate with the virtualization switch 11 via each output port 250 .
The transfer unit 230 refers to the transfer information table 231 and transfers an input-output request received from the host processor 12 via the input port 240 to the output port 250 that is used for the communication between the storage device 13 and the virtualization switch 11 of a requesting destination. Further, the transfer unit 230 transports the response information or data received from the storage device 13 via the output port 250 to the input port 240 that is used for the communication between the host processor 12 and the virtualization switch 11 which ought to receive the information or data. When the input-output request received from the host processor 12 is an input-output request to the virtual volume 100 , the transfer unit 230 enqueues the input-output request to an input queue 241 to be described later and requests the processing from the processor 210 . Further, the transfer unit transfers the input-output request stacked on an output queue 251 to be described later to the storage device 13 via the output port.
The processor 210 executes a program stored on the memory 220 and performs the input-output processing or the change processing of the configuration information for the virtual volume 100 from the host processor 12 .
The memory 220 stores the program the processor 210 executes and the information necessary for the execution. The program and data the memory 220 stores includes a configuration management program 211 , an I/O processing program 213 , the input queue 241 , the output queue 251 , a on-hold queue 242 , a in-process queue 252 , configuration information 221 , and a configuration information difference 222 .
The configuration management program 211 receives a request from the configuration change controller 16 and performs input-output temporary hold and restart processing or configuration information change processing.
The I/O processing program 213 processes the input-output processing for the virtual volume 100 from the host processor 12 , that is, converts the input-output to the input-output for the storage device 13 and transfers it.
The input queue 241 allows the transfer unit 230 to stack the input-output request for the virtual volume 100 . The output queue 251 stacks the input-output request for the storage device the I/O processing program 213 processed. The number of input queues 241 and the number of output queues 251 are optional.
The on-hold queue 242 stores the input-output request for the virtual volume 100 accepted when setting the virtualization switch 11 in a state (I/O temporary hold state) at which the input-output processing is held temporarily. The in-process queue 252 stores the input-output request for the virtual volume 100 processed by the virtualization switch 11 and transferred to the storage device 13 until the input-output is completed.
The configuration information 221 is the table for associating the virtual volume 100 with the real area 132 . The configuration information difference 222 is a buffer that records the difference before and after th change when the configuration information 221 is changed.
In this embodiment, one each of the on-hold queue 242 , in-process queue 252 , configuration information 221 , and configuration information difference 222 is provided for every virtualization switch 11 .
The communication unit 260 enables the processor 210 to communicate with the configuration change controller 16 and the management console 14 via the LAN 15 .
FIG. 3 shows the internal configuration of the configuration change controller 16 of FIG. 1 .
The configuration change controller 16 is a management server, for example, and is provided with a processor 161 , a memory 162 , the bus 270 , and the communication unit 260 . The processor 161 , memory 162 , and communication unit 260 are all connected to the bus 270 , and send and receive data one after another.
The processor 161 executes the program stored on the memory 162 and controls the configuration change of the virtualization switch 11 .
The memory 162 stores the program the processor 161 executes or the information necessary for the execution. The program and data the memory 162 stores includes the configuration change control program 212 , configuration information 221 , and configuration information difference 222 .
The configuration change control program 212 controls the configuration change of the virtualization switch 11 .
FIG. 4 shows the table of the configuration information 221 in a storage system. The configuration information table 221 is provided in the virtualization switch 11 and the configuration change controller 16 .
The configuration information 221 is provided with entries that include a virtual volume address 41 , an offset 42 , a size 43 , an LU address 44 , and an offset 45 . Each entry is associated with a real area 132 and a partial area on the virtual volume 100 to which the real area 132 is allocated. The LU address 44 indicates the information for allowing the virtualization switch 11 to identify the LU 131 including the real area 132 that corresponds to the entry. The offset 45 indicates the start address on the LU 131 of the real area 132 , and the size 43 indicates the size of the real area 132 .
The virtual volume address 41 indicates the information for allowing the host processor 12 to identify the virtual volume 100 , and the offset 42 indicates the start address on the virtual volume 100 of the partial area that corresponds to the entry. The virtual volume address 41 and the LU address 44 specifically use a pair of a WWN (World Wide Name) or port ID, and a LUN (Logical Unit Number) of a fibre channel.
Next, the configuration change in this storage system is described briefly with reference to FIG. 5 . FIG. 5 shows th communication protocol between the configuration change controller 16 and the virtualization switch 11 in the storage system.
When an instruction of a configuration information change request is input from the management console 14 , the instruction is transferred to the configuration change controller 16 ( 501 ). Then the processing of steps 502 to 505 is executed and the input-output processing issued by the host processor 12 is held temporarily. This is because a conflict occurs if the input-output being processed exists before and after a configuration change. If the configuration information is changed during input-output processing in this manner, the input-output cannot be associated with the correct real area 132 and it may cause a data corruption. This data corruption is prevented from the following processing.
That is, the configuration change controller 16 that received a configuration instruction issues a request that temporarily holds the input-output processing (I/O temporary hold request) to all virtualization switches 11 ( 502 ). The virtualization switch 11 that received this hold request holds the input-output being processed and subsequent input-output processing temporarily and waits for the execution completion of the input-output being processed ( 503 ). After the execution is completed, the completion of the processing of the step 503 (I/O temporary hold completion report) is reported to the configuration change controller 16 ( 504 ). Subsequently, the configuration change controller 16 waits for the completion report from all the virtualization switches 11 ( 505 ).
The aforementioned processing enabled the change of configuration information. Subsequently, the processing of steps 506 to 509 is executed and the configuration information of all the virtualization switches 11 is changed collectively. This is because of the possibility of data corruption occurring when the input-output that corresponds to the same virtual volume is associated with the different real area 132 by the virtualization switch 11 in charge of processing if the consistency of the configuration information which the virtualization switch 11 has is not obtained.
The configuration change controller 16 sends a configuration information difference and a configuration information change request that used the difference to all the virtualization switches 11 ( 506 ). The virtualization switch 11 that received the request changes the configuration information ( 507 ). Then after the configuration change was completed, the virtualization switch reports the completion of the configuration information change to the configuration change controller 16 ( 508 ). Subsequently, the configuration change controller 16 waits for the completion report from all the virtualization switches 11 ( 509 ).
Finally, the processing of steps 510 to 513 is executed and the input-outputs held temporarily in the step 503 begin being restarted.
The configuration change controller 16 issues a request (I/O restart request) that restarts the input-output processing held temporarily to all the virtualization switches 11 ( 510 ). The virtualization switch 11 that received the request restarts the input-outputs that are held temporarily ( 511 ). Then the virtualization switch reports the completion of the restart processing to the configuration change controller 16 ( 512 ). Subsequently, the configuration change controller 16 waits for the completion report from all the virtualization switches 11 ( 513 ) and reports the completion to a management console ( 514 ).
The configuration change is enabled without generating a conflict of the configuration information during input-output processing (that is, system operation) or a conflict of the configuration information between the plural virtualization switches 11 in this manner.
Next, the processing operation of the configuration change control program 212 in the configuration change controller 16 is described with reference to FIG. 6 .
First, the processor 161 issues an I/O temporary hold request to all the virtualization switches 11 and waits for a completion report from all the virtualization switches 11 ( 601 ). When queuing was completed normally ( 602 “Y”), the change of the configuration information 221 is enabled. In this case, the processor 161 sends a configuration change request and the configuration information difference 222 to all the virtualization switches 11 and changes the configuration information 221 . Then the processor waits for the completion report from all the virtualization switches 11 ( 603 ). When the queuing was completed normally ( 604 “Y”), the configuration information 221 is changed normally. Accordingly, to restart the input-output being held, the processor 161 sends an I/O restart request to all the virtualization switches 11 and waits for the completion report from all the virtualization switches 11 ( 605 ). When the queuing is completed normally ( 606 “Y”), the processor determines that all change processing has succeeded and returns a message indicating that the processing succeeded to the management console 14 ( 607 ). The aforementioned is a flow of the normal processing of the configuration change control program 212 .
On the other hand, when the virtualization switch 11 did not complete an I/O temporary hold request ( 602 “N”), it determines whether subsequent processing continues or not ( 608 ).
In this embodiment, when there are two or more of virtualization switches 11 to which a response of success was returned, the processing continues ( 608 “Y”). To prevent the virtualization switch 11 to which the response of success was not returned from being used, the virtualization switch is removed from a control range ( 611 ) and the processing continues from the step 603 . When several virtualization switches 11 are removed from the control range in the step 611 , they are utilized based on the incorrect configuration information 221 if the input-output of these virtualization switches 11 is restarted incorrectly. Accordingly, the processor 161 reports the virtualization switch 11 that was removed from the control range to the management console 14 in the step 607 and displays a message indicating “Several virtualization switches were stopped because the synchronization of the input-output temporary hold failed and configuration could not be changed during a configuration” change on the display device of the management console 14 ”.
Further, when the processing does not continue ( 608 “N”), the processor 161 first sends an I/O restart request to all the virtualization switches 11 and waits for the completion report from all the virtualization switches 11 ( 609 ), then determines whether the processing of the step 601 and later steps is retried or not ( 610 ). In this case, when the error in the step 602 was a timeout, this timeout is considered to result from the fact that because the virtualization switch 11 is processing a large amount of input-output, their completion can hardly be waited for. Accordingly, because there is the possibility of this completion wait proving successful by a retry, the retry is performed only for a predetermined count in this embodiment if there are no other errors ( 610 “Y”). In the step 610 and later steps, the processor 161 repeats processing from the step 601 .
On the other hand, when the processing is not retried ( 610 “N”), if there is the virtualization switch 11 to which a response of success was not returned in the step 609 , this switch is removed from the control range ( 617 ). Then the occurrence of an error and its cause are reported to the management console 14 and the management console displays a message indicating “An input-output completion wait of a virtualization switch failed” ( 616 ). More desirably, the management console 14 displays a message prompting the administrator to “Retry a configuration change when the input-output frequency from the host processor 12 to the virtual volume 100 is low”.
Further, when error detection, that is, the change of the configuration information 221 failed in the step 604 , the processor 161 returns to the original configuration information 221 ( 612 , 613 ) and restarts the input-output ( 614 , 615 ). Then the processor reports the occurrence of an error and its cause to the management console 14 , and, for example, displays a message indicating “The administrator failed in the change to the specified configuration information” ( 616 ).
When an error was detected in the processing of the steps 613 and 615 (for “N”), subsequent processing cannot continue. Accordingly, the processor 161 removes the virtualization switch 11 to which the response of success was not returned from the control range ( 617 ) and performs the processing of the step 616 . For example, the processor displays a message indicating “The administrator failed in the change to the configuration information and failed in even recovery processing”. The processor 161 controls the change of the configuration information 221 as described above.
Next, the processing operation of the configuration management program 211 in the virtualization switch 11 is described with reference to FIG. 7 .
The configuration management program 211 is called when the virtualization switch 11 received any of an I/O temporary hold request, an I/O restart request, and a configuration information change request from the configuration change controller 16 . First, when the processor 210 received the I/O temporary hold request ( 701 “Y”), the processor calls the I/O processing program 213 and sets the I/O in a temporary hold state ( 702 ). Then when the transition to the temporary hold state succeeded ( 703 “Y”), the processor 210 returns a response of success to the processor 161 that executes the configuration change program 212 ( 704 ).
Next, when the processor 210 receives the configuration information change request ( 705 “Y”), the processor 210 confirms that the I/O is set in the temporary hold state ( 706 ). This is because the processor 210 does not change the configuration information 221 incorrectly during input-output processing. Further, the processor 210 changes the configuration information 221 ( 707 ). As a result, when the processor 210 was able to change the configuration information normally ( 708 “Y”), the processor executes the processing of the step 704 .
Moreover, when the processor 210 received the I/O restart request ( 709 “Y”), the processor confirms that the I/O is set in the temporary hold state ( 710 ). As a result, when the I/O is set in the hold state ( 710 “Y”), the processor 210 calls the I/O processing program 213 and releases the I/O temporary hold state, then restarts input-output ( 711 ). When the processor 210 was able to change the configuration information normally ( 712 “Y”), the processor executes the processing of the step 704 . The aforementioned is the normal path of the configuration management program 211 .
On the other hand, the configuration management program goes to an abnormal path if No (“N”) is selected in the steps 703 , 706 , 708 , 710 , and 712 . In any case, an error and its cause are returned to the processor 161 ( 713 ).
The processor 210 can change the configuration information 221 in accordance with the instruction of the configuration change controller 16 by executing the configuration management program 211 in this manner.
Next, the processing operation of the I/O processing program 215 in the virtualization switch 11 is described with reference to FIG. 8 .
The I/O processing program 213 is called when an input-output request was enqueued to the input queue 241 , when the input-output request of the in-process queue 252 was completed, when the I/O shifts to a temporary hold state by the processing of the configuration management program 211 , and when the I/Os temporary hold state are release according to the I/O restart request.
When the input-output request enqueued to the input queue 241 ( 801 ), the processor 210 processes the input-output request when the I/O is not set in the temporary hold state ( 802 “N”). That is, the processor 210 converts the address of the virtual volume 100 to the address of the LU 131 with reference to the configuration information 221 and enqueues the input-output request to the output queue 251 (hereafter referred to as the fact that the input-output request was processed). Then the processor enqueues the output-output request to the in-process queue 252 ( 803 ). Subsequently, the processor 210 executes an event wait ( 804 ) and waits for the following activation cause.
On the other hand, when the I/O is set in the temporary hold state ( 802 “Y”), the processor 210 enqueues the input-output request to the on-hold queue 242 ( 805 ) and executes the processing of the step 804 and later steps.
When the processor 210 completed the input-output request of the in-process queue 252 ( 807 “Y”), the processor dequeues the input-output request from the in-process queue 252 ( 808 ). Then the processor confirms whether the I/O is set in the temporary hold state or not ( 809 ). If the I/O is not set in the temporary hold state ( 809 “N”), the processor 210 executes the processing of the step 804 and later steps.
On the other hand, when the I/O is set in the temporary hold state ( 809 “Y”), the processor 210 verifies the in-process queue 252 ( 810 ). As a result of the verification, when the in-process queue 252 was empty ( 810 “Y”), the processor reports the transition completion to an I/O hold state to the configuration management program 211 ( 811 ) and completes the processing. To the contrary, when the in-process queue 252 is not empty ( 810 “N”), the processor 210 repeats the processing from the step 804 .
When the I/O shifts to the temporary hold state ( 812 “Y”), the processor 210 stores that the I/O was set in the temporary hold state ( 813 , 814 ) and continues the processing from the step 810 .
Further, when receiving the restart request ( 815 “Y”), the processor confirms whether the I/O is set in the temporary state or not ( 816 ). As a result of the confirmation, if the I/O is set in the hold state, the processor releases the I/O temporary hold state and processes the input-output of the on-hold queue 242 , then enqueues to the in-process queue 252 ( 817 ). Then when the in-process queue was enqueued normally ( 818 “Y”), the processor executes the processing of the step 811 (that is, completion report). The aforementioned is the processing when the I/O processing program 213 was executed normally.
To the contrary, if the processing of the I/O processing program 213 is not normal, it indicates that No (“N”) was selected in the steps 814 , 816 , 818 . In these cases, because any processing cannot continue, an error and its cause are returned to the configuration management program 211 ( 819 ).
In this embodiment, the input-output processing during the change of the configuration information 221 that causes data corruption is prevented in the step 610 when the configuration change control program 212 is executed and a conflict of the configuration information 221 between the virtualization switches 11 that causes the data damage is prevented in the step 603 in the same manner.
Next, a second embodiment is described with reference to FIGS. 9 to 11 .
FIG. 9 shows the internal configuration of the virtualization switch 11 in a storage system.
FIG. 9 differs from the virtualization switch 11 shown in FIG. 2 in that the processor 161 connected to the bus 270 is provided, the configuration change control program 212 is stored in the memory 220 , and the processor 161 executes this configuration change control program 212 . In this case, the processor 161 is provided with a timer 165 , and the processing of the configuration change control program 212 is activated periodically by this timer 165 . The timer 165 may be a timer realized by software.
According to this embodiment, the virtualization switch 11 can function as the configuration change controller 16 by incorporating the configuration change control program 212 and the processor 161 in the virtualization switch 11 (the virtualization switch 11 that functions in this manner is also hereafter referred to as the configuration change controller 16 ). When the plural virtualization switches 11 are provided, they are all provided with the aforementioned configuration and can function as the configuration change controller 16 . If all the virtualization switches 11 are provided with the configuration change control program 212 and the processor 161 in this manner, the configuration change controller 16 in the system shown in FIG. 1 becomes necessary.
The processor 210 provided in the virtualization switch 11 can use the function of the processor 161 simultaneously.
FIG. 10 shows the processing of the configuration change control program 212 in the second embodiment. FIG. 10 differs from FIG. 6 in that arbitration processing 600 is included as the processing operation of FIG. 10 . FIG. 11 shows a detailed flow of the arbitration processing 600 .
The arbitration processing 600 limits, among the plural processors 161 that correspond to the plural virtualization switches 11 , processors (hereafter referred to as a processor having a master right) that executes the processing of the step 601 and later steps to one processor. In this embodiment, the configuration change control program 212 is also activated by receiving a monitoring packet from another configuration change control program 16 (incorporated in the virtualization switch 11 ) and the timer 165 in addition to a configuration change request from the management console 14 .
In the flowchart of FIG. 11 , first, when the processor 161 received a monitoring packet ( 1101 “Y”), the processor returns a response packet to the configuration change controller 16 that sent this monitoring packet ( 1102 ), completes the arbitration processing, and also completes the processing of the configuration change control program 212 ( 1110 ).
The monitoring packet and the response packet include the ID of the sent configuration change controller 16 and the ID (hereafter referred to as the ID of a controller having a master right) of the configuration change controller 16 that incorporates the processor having the master right. These identifiers identify the configuration change controller 16 . For example, the identifiers are IP addresses which the communication unit 260 has. When the processor 161 received a configuration change request from a management console ( 1103 “Y”), the processor 161 asserts the master right to another configuration change controller 16 , that is, the processor 161 sends the monitoring packet in which the ID of the local configuration change controller 16 was recorded as the ID of the controller having the master right to all the configuration change controllers 16 and waits for a response ( 1104 ). For a normal end, that is, when the processor did not receive the response packet that has the ID other than the local configuration change controller 16 as the ID of the controller having the master right ( 1105 “Y”), the processor completes processing and shifts to the processing of the step 601 of the configuration change control program 212 ( 1106 ).
In the step 1103 , when the program was called with the timing of the timer 165 , the processor 161 monitors the remote configuration change controller 16 , that is, sends the monitoring packet to the controller having the master right ( 1107 ). For the normal end, that is, when the processor received the response packet that has the ID of the controller as the ID of the controller having the master right ( 1108 “Y”), the processor advances to the processing of step 1110 and completes the processing. The aforementioned is the normal case of the arbitration processing.
To the contrary, for abnormal processing, that is, when negation (“N”) was selected in th steps 1105 , 1108 , because there is another controller having the master right, the processor sends notice as such to the management console 14 ( 1109 ), the processor goes to the processing of the step 1110 and completes the processing.
Because another processing operation is the same as the aforementioned first embodiment, the description is omitted.
Thus, according to the second embodiment, the controller having the master right is limited to only the controller 16 that received a configuration change request from the management console 14 at first by the processing of the steps 1104 , 1102 . That is, even if the plural processors 161 execute the configuration change control program 212 in a system, they can change the configuration information 221 without generating a conflict.
When a fault occurred in the controller 16 having the master right, the system administrator can identify this fault via the management console 14 through the processing of the steps 1107 , 1102 .
Next, a third embodiment is described with reference to FIGS. 12 to 18 .
FIG. 12 shows the internal configuration of the virtualization switch 11 in a storage system.
As compared with the virtualization switch 11 shown in FIG. 9 , FIG. 12 differs in that a temporary hold control table 223 is provided, the plural in-process queues 252 are provided, and double-buffered configuration information 221 a , 221 b is provided. The processor is provided with the timer 215 .
The temporary hold control table 223 controls whether the input-output is held temporarily by storing the result of associating each entry of the configuration information 221 with the in-process queue 252 . The reason why the plural queues to be processed 252 are provided is to limit a completion wait and input-output held temporarily by dividing the in-process queues 252 according to an input-output destination address. The configuration information 221 has double-buffereds to shorten the processing time in the I/O temporary hold state by switching the face of the configuration information 221 . Further, the timer 215 is installed to set the processing of the I/O processing program 213 by the processor 210 and detect a timeout of the I/O temporary hold state.
FIG. 13 shows the communication protocol between the configuration change controller 16 and the virtualization switch 11 in the third embodiment.
In this embodiment, because only one virtualization switch enables a configuration change control function in the plural virtualization switches 11 , the communication becomes necessary between the virtualization switch 11 in which the configuration change control function is effective and the virtualization switch 11 the function of which is not effective. The communication protocol is the example shown in FIG. 13 . The same communication is performed even in the same virtualization switch 11 . Accordingly, you are requested to assume that the “Configuration Change Control Function” shown in FIG. 13 indicates the processor 161 of FIG. 12 or the configuration change control program 212 that is executed there and the “Virtualization Switch 11 ” indicates the processor 210 in the local and remote virtualization switches 11 or the configuration management program 211 that is executed there and to refer to both.
FIG. 13 differs from the communication protocol shown in FIG. 5 in that steps 531 to 533 are added between the steps 501 and 502 . Further, a configuration information switching request is sent instead of sending a configuration information change request in the steps 506 to 508 of FIG. 5 .
In step 530 , the processor 161 sends the configuration information difference 222 to all the virtualization switches 11 ( 530 ). All the virtualization switches 11 store the configuration information difference and create the configuration information 221 ( 531 ). The virtualization switch 11 creates the face ( 221 b here) that is not used by the I/O processing program 213 of the configuration information 221 . Subsequently, the virtualization switch 11 returns a configuration information difference receiving completion report to the configuration controller 16 ( 532 , 533 ).
Further, in step 507 ′, the virtualization switch 11 switches the configuration information 221 a to the configuration information 221 b . The processing time can be reduced because the processing during an I/O temporary hold state (between the steps 503 and 511 ) is completed only by switching the face of the configuration information 221 in the step 507 ′ in this way.
FIG. 14 shows an example of the temporary hold control table 223 in FIG. 12 .
The temporary hold control table 223 has a plurality of entries. Each entry has a temporary hold state 2231 and a in-process queue ID 2232 . The temporary hold state 2231 and the in-process queue ID 2232 are both provided to limit a completion wait and input-output held temporarily. As the initial values of the temporary hold state 2231 and the in-process queue ID 2232 , the processor 210 stores the ID of the in-process queue 252 that is not in a temporary hold state and empty (not associated with the temporary hold control table 223 ) respectively when the virtualization switch 11 is initialized or when the virtual volume 100 is created. When the empty in-process queue 252 is provided, the processor 210 creates the in-process queue 252 anew and stores the ID as the ID 2232 .
FIG. 15 shows the configuration information 221 in FIG. 12 .
FIG. 15 differs from the table with the table shown in FIG. 4 in that an index 411 of the control table 223 is provided. The index 411 specifies the entry of the temporary hold control table 223 . The entry of the configuration information 221 , that is, the address range on the virtual volume 100 is associated with the temporary hold state 2231 and the in-process queue 252 through the entry of the temporary hold control table 223 . Accordingly, whether input-output is held temporarily per address range can be controlled.
FIG. 16 shows the processing of the configuration change control program 212 in the virtualization switches 11 shown in FIG. 12 .
FIG. 16 differs from FIG. 10 in that steps 625 and 626 are inserted next to the arbitration processing (step 600 ) and step 627 is inserted next to the step 602 . Further, steps 603 ′ and 612 ′ are included instead of the steps 603 and 612 .
The processing of the steps 625 and 626 is the same as the procedures 530 , 533 of FIG. 13 . In the step 627 , the processor 161 issues an I/O temporary restart request once ( 609 ) and retries the processing of the step 601 and later steps when the processor 210 detects a timeout of the I/O temporary hold state during processing of the I/O processing program 213 ( 627 “Y”).
In this step 627 , an I/O temporary hold state can be set prior to an input-output timeout by the host processor 12 . Further, in the steps 603 ′ and 612 ′, the processing of switching the configuration information from 221 a to 221 b is requested from the virtualization switch 11 instead of rewiring the configuration information 221 . Because the switching processing of the configuration 221 is completed in a shorter time than rewriting the configuration information to a memory, the time of the I/O temporary hold state can be reduced as a result.
FIG. 17 shows the processing of the configuration program 211 in the virtualization switch 11 of FIG. 12 .
FIG. 17 differs from the flowchart shown in FIG. 7 in that steps 714 to 718 were added next to the step 709 “N”. In the step 707 , among the configuration information 221 , the face ( 221 b ) which the I/O processing program 213 does not use is updated. The processing of steps 714 “Y” to 704 is the same as the steps 507 ′, 508 ′ of FIG. 13 .
The configuration management program 211 is called when a request from the I/O processing program 213 is issued in addition to an I/O temporary hold request, an I/O restart request, a configuration information update request, and a configuration information switching request. When this request is provided, processing goes to the step 601 “N”. Subsequently, the processor 210 transfers the request of the I/O processing program 213 to the configuration change controller 16 ( 718 ). This processing can retry the processing in the configuration change control program 212 on a timeout of an I/O temporarily stopped state.
Further, the processing of the steps 705 to 704 is the same as the procedures 531 , 532 of FIG. 13 .
FIG. 18 shows the processing of the I/O processing program 213 in FIG. 12 .
FIG. 18 differs from the flowchart of FIG. 8 in the processing contents of the steps 802 , 803 , 805 , 808 , 809 , 810 , 813 , 816 , 817 .
In steps 802 ′, 809 ′, 816 ′, the processor 210 determines that the I/O is set in a temporary hold state by checking the temporary hold state 2231 of the entry the index 411 in the configuration information 221 specifies. This can control whether the input-output is held temporarily or not per address range of the virtual volume 100 that is an input-output destination.
Further, in steps 803 ′ and 808 ′, the processor 210 uses the in-process queue 252 specified with the ID 2232 of the in-process queue of the entry which the index 411 in the configuration information 221 specifies as the in-process queue 252 .
Further, in step 813 ′, the processor 210 changes a state so that only the input-output for an area on the virtual volume 100 defined according to the contents of the configuration information difference 222 can be set in the temporary hold state. Specifically, the processor 210 lists up the index 411 of the configuration information 221 a that corresponds to all entries registered in the configuration information difference 222 and changes all the temporary hold states 2231 of the entry that corresponds to these indexes 411 during a temporary hold. As described already, in the step 802 ′, this temporary hold state 2231 is checked. Accordingly, the output-output request that corresponds to this temporary hold state 2231 , that is, only the input-output request affected by the configuration information difference 222 is held.
In step 810 ′, the processor 210 lists up the index 411 of the configuration information 221 a that corresponds to all entries registered in the configuration information difference 222 and checks all the in-process queues 252 specified by the in-process queue ID 2232 of the entry that corresponds to these indexes 411 , then determines whether the in-process queue 252 becomes empty or not.
In step 805 ′, the processor 210 enqueues to the in-process queue 252 shown in the in-process queue ID 2232 and sets the timer 215 . In step 817 ′, the processor 210 resets the timer 215 , resets the temporary hold state 2231 held in step 813 ′, processes the input-output enqueued to the on-hold queue 242 , and enqueues to the queue be processed 252 shown in the in-process queue ID 2232 .
In the step 820 “Y”, the processor 210 starts the processing of the I/O processing program 213 on the timeout of the timer 215 . In this case, the processor 210 executes the processing of the step 819 and returns an error to a configuration management program. The processor 210 executes the processing of the step 818 .
Because other aspects are the same as the second embodiment, the description is omitted.
In the third embodiment, the time of the I/O temporary hold state can be reduced in the steps 625 and 603 ′ in this manner. The time of the I/O temporary hold state can be limited by releasing the I/O temporary hold state and retrying the processing in the steps 805 ′, 820 , 627 . This can prevent the input-output timeout or performance deterioration in the host processor 12 .
Further, in this embodiment, it is possible to limit input-output temporarily held in steps 813 ′ and 802 ′ to a range affected by the configuration change. Accordingly, it is possible to prevent deterioration of performance by the configuration change.
As a modification example of this embodiment, there is also a method for being not provided with the aforementioned double-buffered configuration information 221 and not executing the processing of the step 625 . For example, the processing of the step 603 (rewriting of the configuration information 221 in the first embodiment) may also be performed instead of step 603 ′ in which the configuration information 221 is switched. In that case, although the time of the I/O temporary hold state is prolonged, the capacity of the memory 220 can be suppressed.
Next, a fourth embodiment is described with reference to FIGS. 19 to 26 .
FIG. 19 shows the internal configuration of the virtualization switch 11 in the fourth embodiment.
FIG. 19 differs from the configuration shown in FIG. 12 in that a copy processing program 214 and a copy progress table 224 are added and the one-face configuration information 221 is provided.
When the copy processing program 214 is executed by the processor 210 and changes the LU 1311 to which the virtual volume 100 corresponds to the other LU 1312 , the program copies data from the LU 1311 to the LU 1312 . The copy progress table 224 is used to manage advancement of the copy processing in the copy processing program 214 and has a plurality of entries. Each entry corresponds to the real area 132 that constructs the LU 131 . In this embodiment, the configuration information difference 222 is generated during I/O temporary stop. Accordingly, the configuration information 221 has only one face. Other aspects are the same as FIG. 12 .
FIG. 20 shows an example of the configuration information 221 in the virtualization switch 11 of FIG. 19 .
As compared with FIG. 15 , in FIG. 20 , a total of three pairs of the LU address and offset consisting of on pair of 44 and 45 for the Read command and two pairs of 46 and 47 , and 48 and 49 for the Write command are provided. In this embodiment, the correspondence of the virtual volume 100 differs in the Write and Read commands due to the progress of the copy processing program 214 . Further, in the case of Write operation, because dual writing is also performed to the LU 1311 and the LU 1312 , two pairs of the address and offset for the Write command are prepared.
FIG. 21 shows the processing of the configuration change control program 212 in the virtualization switch 11 of FIG. 19 .
As compared with the flowchart of FIG. 16 , in FIG. 21 , steps 631 to 633 and 635 are added between the steps 627 and 603 and step 634 is added between the steps 606 and 607 . Further, the processing of the steps 603 , 612 is performed instead of the steps 603 ′, 612 ′.
In the copy processing 631 , the processor 161 starts the copy processing program 214 . When copying is performed without any error ( 632 “Y”), the processor 210 refers to the copy progress table 224 and creates the configuration information difference 222 . The details of difference creation will be described later with reference to FIG. 26 .
In the step 634 , the processor 161 determines whether the copying from the LU 1311 to the LU 1212 was all completed by checking the copy progress table 224 . When the copying is completed ( 634 “Y”), the processor 161 executes the processing of the step 607 and completes the processing. On the other hand, when the copying is not completed ( 634 “N”), the processor 161 repeats the processing from the step 601 .
When the copying ended abnormally ( 632 “N”), the processor 161 performs recovery processing ( 635 ). Specifically, the processor 161 creates the difference 222 so that the configuration information 221 before executing the configuration change control program 212 can be returned and issues a configuration change request to all the virtualization switches 11 , then waits for the completion. Further, the processor 161 executes the processing of the step 614 and later steps and reports an error to a management console, then completes the processing.
FIG. 22 shows the detailed processing operation of the copy processing 631 shown in the flowchart of FIG. 21 .
First, the processor 161 sends a copy start request to the processor 210 and activates the copy processing program 214 ( 6312 ) after activating the configuration change control program 212 and then activating first copy processing 6311 ( 6311 “Y”). with the copy start request, the processor 161 instructs the address range in which copying is performed by the activation of the copy processing program 214 to the processor 210 .
On the other hand, when no initial activation is performed ( 6311 “N”), the processor sends the copy restart request to the processor 210 and activates the copy processing program 214 ( 6313 ). Also in this case, the processor instructs the address range in which the copying is performed by the activation of this copy processing program 214 to the processor 210 . In both cases, the processor 161 subsequently enters an event wait state ( 6314 ). The events for which the processor 161 waits are the completion of the copy processing program 214 and the receiving of a copy priority request or a copy interrupt request in step 718 to be described later. When the processing of the copy processing program 214 was completed ( 6315 “N”, 6316 “N”), the processor 161 shifts to step 632 .
For the copy interrupt request ( 6315 “Y”), the processor sends the copy interrupt request to the processor 210 and activates the copy processing program 214 ( 6317 ). For the copy priority request, the processor interrupts the copying once and performs the processing from the step 6315 . Subsequently, because the copy processing must be reactivated, the processor 161 executes the step 6316 “Y” and repeats the processing of the step 6313 and later steps. At that time, because the processor transfers an address to be copied preferentially from the processor 210 , it specifies the range that includes the address in the step 6313 .
As described in the steps 6312 and 6313 , the copy processing program 214 is activated plural times. Further, in the step 6317 , the copying is interrupted once. Consequently, the time the input-output is held temporarily can be reduced.
FIG. 23 shows the processing of the configuration management program 211 in the virtualization switch 11 of FIG. 19 .
In this embodiment, because the face of the configuration information 221 is not switched during I/O temporary hold state, the processing of the configuration management program 211 is similar to that shown in the first embodiment. Accordingly, when FIG. 23 is compared with the flowchart of FIG. 7 , FIG. 23 differs from FIG. 7 in that step 718 is added.
In this embodiment, the timing the configuration management program 211 is called is caused by a copy priority request or a copy interrupt request from the I/O processing program 213 in addition to the case of FIG. 7 . In either case, the processor 210 determines as No in step 709 and issues the copy priority request or copy interrupt request to the processor 161 ( 718 ). For the copy priority request, however, because the processor 210 transfers an address to be copied preferentially from the I/O processing program 213 , it also transfers the address to the processor 161 .
Thus, the configuration management program 211 reflects a request caused by the processing of the I/O processing program 213 in the processing of the configuration change control program 212 by the processing of the step 718 .
FIG. 24 shows the processing of the I/O processing program 213 in the virtualization switch 11 of FIG. 19 .
In comparison with the flowchart shown in FIG. 18 , in FIG. 24 , step 806 is added next to the step 805 ′ and step 821 is added next to the step 820 .
In the step 806 , the processor 210 calls the configuration management program 211 and requests copy priority when the accepted input-output is Write operation. In that case, the processor transfers the address range written by the accepted input-output to the configuration management program 211 .
In this embodiment, because the timeout ( 820 “Y”) of the timer 215 is caused by the copy processing, in the step 821 , the processor 210 calls the configuration management program 211 and requests a copy interrupt.
When the copy processing by the input-output held temporarily is interrupted or made to take preference by the processing of the steps 806 and 821 , the time the input-output is held temporarily can be reduced.
In step 806 , by making a copy interrupt request when the accepted input-output is read, the time the input-output is held temporarily can be further reduced (In this case, the step 821 becomes unnecessary). The copy processing, however, is as delayed as this operation.
FIG. 25 shows the processing of the copy processing program 214 in th virtualization 11 of FIG. 19 .
The copy processing program 214 is activated at the timing of the completion of a copy start request, a copy restart request, and a copy interrupt request from the configuration change control program 212 , and the input-output that copies data actually. When the copy start request is provided ( 901 “Y”), the processor 210 initializes all the entries of the copy progress table 224 to a value (“0” in this example) that indicates Uncopied ( 902 ). Subsequently, the entry of the copy progress table that corresponds to the address range transferred from the configuration change control program 212 is set to a value (“1” in this example) that indicates Being Copied ( 903 ).
Further, the processor 210 issues an input-output instruction (hereafter referred to as COPY I/O) that performs copying to the area set to “1” (Being Copied) in the copy progress table 224 ( 904 ). Specifically, the input-output request that performs copying is generated and enqueued to the output queue 251 . Further, the processor 210 waits for an event ( 905 ). Among the activation timings of the copy processing program 214 , the processor waits for a request: other than the copy start request and executes the processing of step 906 and later steps. Further, when the copy restart request was provided ( 906 “Y”), the processor 210 repeats the processing of the step 903 and later steps.
When COPY I/O is completed ( 907 “Y”), the processor 210 confirms that the result of this input-output ends normally ( 908 “Y”) and updates the copy progress table 224 ( 909 ). Specifically, the processor sets a value (“4” in this example) that indicates Copied in an entry where COPY I/O was completed and sets a value that indicates a copy interrupt (in this example, “0” (Uncopied) in the entry in which “2” is stored). Further, when there is no entry in which “1” (Being Copied) in the entry of the copy progress table 224 , the processor 210 returns a response of success to the configuration change control program 212 and completes the processing ( 911 ). When there is an entry being copied ( 910 “N”), the processor 210 repeats the processing from the step 904 .
When the copy interrupt request is received ( 912 “Y”), the processor 210 sets “2” (Copy Interrupted) in all entries where “1” of the copy progress table 224 is set and repeats the processing from the step 905 .
When COPY I/O ended abnormally ( 908 “N”), the processor 210 sets “0” (Uncopied) in all entries where “1” (Being Copied) and “2” (Copy Interrupted) of the copy progress table 224 are set ( 914 ). Then an error and its cause are returned to the configuration change control program 212 and the processing terminates ( 915 ).
The copy processing program 214 can copy data by the processing of the COPY I/O of the step 904 in this manner.
The operation principle of data migration according to the fourth embodiment is described with reference to FIG. 26 .
FIG. 26A shows the interrelationship between the virtual volume 100 and th real area 132 , and the interrelationship with the copy progress table 224 in the copy processing 631 .
The arrow from the real area 132 to the virtual volume 100 shows the interrelationship in a Read request to the virtual volume 100 and the arrow from the virtual volume 100 to the real area 132 shows the interrelationship in a Write request to the virtual volume 100 . An arrow marked by a dotted line shows that the input-output to this arrow is held.
Arrows appear from an area 1001 on the virtual volume to a real area 13211 and a real area 13221 . This indicates that the same data is written dually to the two real areas 13211 , 13221 when the Write request is issued to 1001 .
Further, the arrows from real areas 13212 , 13213 to real areas 13222 , 13223 indicate copying is performed in this direction. 2241 a , 2242 a , 2243 a , 2244 a of the copy progress table correspond to areas 1001 , 1002 , 1003 , 1004 on the virtual volume.
FIG. 26A shows that 2241 a is set to Copied “4” and the copying from the real area 13211 to real 13221 is completed regarding an area 100 - 1 . Regarding the copied area, for Read, data is written from a shift destination, that is, 1311 , and, for Write, data is written to both shift source and shift destination, that is, both 1311 and 1312 . This is because the latest data is left in the LU 1311 even when the shift into the LU 1312 failed halfway.
Further, 2242 a to 2244 a are set to Being Copied “1” and indicate that data is copied currently from these corresponding real areas 13212 to 13214 to the real areas 13222 to 13224 . 2245 a is set to Uncopied “0” and indicates copying is not performed from a real area 13215 to a real area 13225 .
FIG. 26B shows the copy progress table 224 after the host processor 12 issued a Write request to the area 1004 . When Write to the area being copied is received, the processor 210 requests copy priority through the step 806 of the I/O processing program 213 ( FIG. 24 ). Subsequently, the processor 161 first performs copy interrupt processing 6317 of the copy processing 631 . As a result, the processor 210 executes the step 912 of the copy processing program 214 . Because the mark “2” of Copy Interrupted is set in the area of Being Copied “1” of the copy progress table 224 , the state of Table 224 b occurs.
Subsequently, the processor 210 waits for the completion of COPY IO and executes the processing of the step 909 , then updates the copy progress table 224 . In this case, if copying to the real area 13222 only is completed, the entry 2242 b that corresponds to this is updated from Copy Interrupted “2” to Copied “4” and another entry is updated from the mark “2” of Copy Interrupted to the mark “0” of Uncopied. Further, the processor 161 performs the processing of the step 6313 in th copy processing 631 and specifies the address of the real area 13214 to the area 1004 . Because the processor 210 performs the processing of the step 906 and later steps of the copy processing program 213 , the processor 210 sets the mark “1” of Being Copied in 2244 b that corresponds to the area 1004 . Thus the processor enters the state of FIG. 26C . That is, the processor 210 preferentially copies data from the real areas 13214 to 13224 .
Because other processing is the same as the third embodiment, the description is omitted.
As described above, the allocation destination of the virtual volume 100 can shift the allocation destination of the virtual volume 100 from the one LU 1311 to the other LU 1312 during system operation.
Next, a fifth embodiment is described with reference to FIGS. 27 and 28 .
FIG. 27 shows the overall configuration of a storage system.
As compared with the system shown in FIG. 1 , in FIG. 27 , the independent configuration change controller 16 is removed, and a configuration change control program 16 ′ is provided in each virtualization switch 11 . Further, a storage device 135 has a copy control unit 136 .
The storage device 135 differs from the storage device 13 and has the communication unit 260 . The storage device 135 is connected to the LAN 15 and has the copy control unit 136 . This enables data to be copied from an LU 131 a within the local storage device 135 to an LU 131 c . Desirably, the copy control unit 136 provided in the storage device 135 should perform copy processing while permitting the input-output from the host processor 12 to the copy source UL 131 (hereafter referred to as ‘Copiable’ during online operation). Needless to say, ‘Copiable’ need not be required during online operation. When copying is not enabled during this online operation, the time the input-output is held temporarily is prolonged.
The copy control unit 136 receives the designation of performing the copy processing from which LU 131 to which LU 131 , for example, of copying data from the LU 131 a to the LU 131 b as well as the request of the start or completion of the copy processing from the configuration change controller 16 or the management console 14 via the communication unit 260 .
FIG. 28 is a flowchart showing the processing of the configuration control program 212 in the fifth embodiment.
FIG. 28 differs FIG. 16 in that the processing of the step 640 is inserted after the step 627 .
In the processing of the step 640 , the processor 161 requests to the copy control unit 136 the completion of the copy processing from the LU 131 a to the LU 131 b and waits for the completion report. When copying is enabled during online processing, the system administrator can request copy start at an optional period before the step 640 . When copying is disabled during online processing, the processor 161 requests to the copy control unit 136 the start of the copy processing in the step 640 prior to the request of the completion. By hastening the request of the copy start, it can be anticipated that await completion report in the step 640 is returned quickly.
The processors 161 and 210 perform the same processing as the third embodiment and changes the configuration so that the virtual volume 100 can correspond to the LU 131 a and the LU 131 b . Because other processing is the same as the third embodiment, the description is omitted.
According to the fifth embodiment, by utilizing the copy function which the storage device 135 has, the allocation destination of the virtual volume 100 can be shifted from the LU 131 a to the LU 131 b even if the function of copying the LU 131 to the virtualization switch 11 is not provided.
Next, yet another example (sixth embodiment) of a storage system is described with reference to FIG. 29 .
In this example, a storage device 137 has a virtualization function. Each storage device 137 has the storage device 13 , copy control unit 136 , and communication unit 260 and the virtualization switch 11 shown in FIG. 27 . Each virtualization switch 11 incorporates the configuration change control program 16 ′ similarly to the aforementioned FIG. 27 and implements the configuration change control function. Because other aspects are the same as the fifth embodiment, the description is omitted.
According to this example, while the system is operating by a virtualization switch having a redundant configuration, a storage device that can shift the allocation destination of the virtual volume 100 from the LU 131 a to the LU 131 b can be realized.
Although several embodiments have been described above, the present invention can be modified variously and executed without being limited to the above examples. For instance, in the examples of FIGS. 12 and 19 , one of the processors 161 and 210 is omitted and the remaining other processor can be used for the processing of a program at the same time. | Disclosed is a storage system having storage devices from which storage areas are specified. Virtualization apparatuses allocate the storage areas as virtual volumes and processes I/O requests with respect to the virtual volumes. A controller is operable to change the allocation of storage areas to the virtual volumes. The controller is configured to send a request to some of the virtualization apparatuses to temporarily suspend processing of their I/O. When a virtualization apparatus receives such a request, it completes its pending I/O and temporarily suspends subsequent I/O requests, and sends a completion report to the controller. The controller then changes the allocation of storage areas to the virtual volumes. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a closure for a container that is adapted to contain a liquid, the closure and the container having cooperating features which impart child-resistant opening characteristics to the package which includes such closure and container, to help to prevent the accidental ingestion of the contents of the container by children. The closure has a separate liner which seals against the container to prevent the leakage or spillage of the contents of the closed container. The closure is designed for use with wide mouth containers, viz., those having a finish dimension ("T" dimension) of at least 33 millimeters.
2. Description of the Prior Art
Various types of child-resistant opening packages are known in the prior art, and certain of such packages include a closure and a container that engage one another in a liquid-tight seal to permit the packaging of a liquid in such container, with the assurance that the liquid will not leak or spill from the container if the container is lying on its side, so long as the closure is securely affixed to the container. For example, U.S. Pat. No. 4,375,858 (H. D. Shah, et al) discloses a child-resistant package in which the closure is of the self-sealing or linerless type, and U.S. Pat. Nos. 3,610,454 (D. M. Malick), 3,952,899 (C. W. Cooke), and 3,979,001 (C. Bogert) disclose child-resistant packages that utilize closures having resilient gaskets to permit such closures to seal against the associated containers. Closures of the aforesaid child-resistant types can be difficult to remove by adults, however, especially by adults who suffer from hand function impairment as a result of arthritis or hand injury, for example, and this problem is more serious in the case of child-resistant packages that utilize wide mouth containers.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a child-resistant container/closure package in which the container is of the wide mouth type, that is, with a container finish diameter, viz., with a container "T" dimension (the approximate outside diameter of the container thread) of at least 33 millimeters. The finish of the container of the package of the present invention has a pair of sets of helically extending threadlike projections extending radially outwardly from the finish. The first set of threadlike projections is positioned above the second set or, in other words, closer to the rim at the mouth of the container. The first set, which functions as a multiple start container thread, is made up of at least a pair of partial thread segments which are disposed in a circumferential pattern on separate helixes. Each of the thread segments in the first set has a vertically extending shoulder formed in the upper side thereof. The second set of threadlike projections is disposed below the first set and defines a circumferential series of helical slots with the first set of threadlike projections.
The closure of the present invention is a two-piece closure which is made up of a molded thermoplastic closure body, including a top panel, a skirt and a multiple start closure thread that is engageable with the first set of threadlike projections on the container finish to permit the closure to be screwed onto and off the container finish. The second piece of the two-piece closure is a springable liner that is inserted into the closure body, near the inside of the top panel, to form a seal between the inside of the top panel of the closure and the rim of the container when the closure is screwed tightly down on the container finish. Each of the segments of the multiple thread start closure thread has a vertically extending shoulder formed in the lower side thereof. The shoulders in the closure thread segments engage the shoulders in the container thread segments after the closure has been partially unscrewed from the container finish to prevent further unscrewing of the closure, and to thereby help to prevent accidental removal of the closure by children unless and until the closure is manually depressed relative to the container finish, a step which will separate the shoulders on the closure thread segments from the shoulders on the container thread segments and will then permit continued unscrewing of the closure to complete the removal process.
The closure is normally resiliently biased upwardly away from the finish by the closure sealing liner to insure that the shoulders in the closure thread segments engage the shoulders in the container thread segments unless and until the closure is manually depressed, against the biasing force of the closure liner. The sealing and biasing effects of the closure liner are obtained through the use of a multilayer, disk-type liner, such liner using a thin layer of a sealing material, such as a thin foam plastic material, backed-up by a thicker layer of a plastic sheet material that acts like a disk spring. A central portion of such a liner is maintained below the level of the inside of the closure top panel by a projection on the inside of the top panel, and this placement of the closure liner allows an annular edge portion of the liner to be flexed upwardly, relative to the central portion, to be compressed against the inside of the closure top panel when the closure is screwed tightly against the container finish, thus, distorting the plastic sheet material in the closure liner and creating the proper biasing force on the closure by virtue of such distortion of the closure liner.
Accordingly, it is an object of the present invention to provide an improved child-resistant container/closure package.
It is a further object of the present invention to provide a child-resistant container/closure package that may utilize a wide mouth container.
It is a further object of the present invention to provide a child-resistant container/closure package in which the container is of the wide mouth type and in which the closure may be mass produced relatively inexpensively by the molding of a thermoplastic material.
It is a further object of the present invention to provide a child-resistant container/closure package in which the container is of the wide mouth type, and which may be utilized in the packaging of a liquid.
It is also a further object of the present invention to provide a child-resistant container/closure package in which the container is of the wide mouth type and is readily formable from plastic by various of the known plastic container manufacturing techniques.
It is also an object of the present invention to provide a child-resistant container/closure package in which the container is of the wide mouth type and which incorporates a feature to assist in the removal of the closure from the container by a person with an injured or arthritic hand.
It is also an object of the present invention to provide a child-resistant container/closure package in which the container is of the wide mouth type, which may be utilized for the packaging of a liquid, and in which the closure, when in sealing engagement with the container, is pulled down against the container at a multiplicity of points around the container to insure good sealing of the closure to the container around the circumference of the container.
It is also an object of the present invention to provide an improved wide mouth container which may be utilized with a suitable closure to provide a child-resistant container/closure package for the packaging of a liquid.
It is also an object of the present invention to provide an improved closure for use with a suitable wide mouth container to provide a child-resistant container/closure package for the packaging of a liquid.
For further understanding of the present invention and the objects thereof, attention is directed to the drawing in the following description thereof, to the detailed description of the invention, and to the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top perspective view of the preferred embodiment of a closure according to the present invention, which closure has utility in combination with a suitable container in the preferred embodiment of a package according to the present invention;
FIG. 2 is a sectional view, at an enlarged scale, taken on line 2--2 of FIG. 1;
FIG. 3 is a bottom plan view of the closure of FIGS. 1 and 2, with an element of the closure shown in FIG. 2 being removed for the sake of clarity;
FIG. 4 is a fragmentary development view of the closure of FIGS. 1 through 3;
FIG. 5 is a fragmentary elevational view of a preferred embodiment of a container according to the present invention, which container has utility in combination with the closure of FIGS. 1 through 4 to form the preferred embodiment of a child-resistant package according to the present invention;
FIG. 6 is a fragmentary development view of the container of FIG. 5;
FIG. 7 is a fragmentary elevational view, in section, showing the closure of FIGS. 1 through 4 in tight, sealing engagement with the container of FIGS. 5 and 6;
FIG. 8 is a view similar to FIG. 7 showing the closure in relationship to the container after the closure has been partially unscrewed from the container, as part of the process of removing the closure from the container;
FIG. 9 is a view similar to FIGS. 7 and 8 which illustrates the step which must be performed, after the closure has reached the condition shown in FIG. 8, before the closure can be further removed from the container; and
FIG. 10 is a fragmentary top perspective view which shows the closure and the container during the performance of the removal step shown in FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
The child-resistant package according to the present invention is made up of a closure, indicated generally by reference numeral 10, and a container, shown fragmentarily and indicated generally by reference numeral 50. The package that includes the closure 10 and the container 50 may be used to package a liquid product, identified generally by reference character P in FIGS. 7, 8, and 9. As is shown in FIG. 2, the closure 10 is made up of a closure body 20 and a liner 40. The closure body 20 is preferably molded in a single piece, as by injection molding or compression molding, from a suitable thermoplastic material, such as high density polyethylene or polypropylene. The liner 40 is of a composite or multi layer construction which includes a lower layer 41 of a suitable pulp or plastic material for sealing against the container 50, such as a foam plastic material, and an upper layer 42 of a springable material, such as a sheetlike plastic material, the upper layer 42 being in surface-to-surface contact with the lower layer 41, and preferably being adhesively or other wise securely bonded thereto. The container 50 is a wide mouth container, having a container "T" dimension of 33 millimeters or greater, and may be considered to be either a blown glass container or a blow molded thermoplastic container, the selection of material for the container 50 normally being based on the susceptibility of the contents of the container to attack by oxygen or other ingredients which may permeate through the wall of a plastic container, or to infra-red or ultra-violet radiation which may pass through the wall of the glass container, all as is well understood in the art.
The container 50 has a neck or "finish" portion 51 that defines an upper open mouth 52 of the container, as shown in FIG. 8, the "finish" portion 51 terminating in a rim 53.
The closure body 20 is made up, in general, of a top panel 21 that spans the upper open mouth 52 of the container 50 when the closure is applied to the container 50, and an annular skirt 22 that extends downwardly from the top panel 21 to surround the finish 51 of the container 50 when the closure is applied to the container 50. The closure body 20 also has a centrally located and downwardly depending projection 23, which preferably is annular in configuration, and which maintains at least the central portion of the liner 40 at an elevation beneath the underside of the top panel 21 of the closure body 20. When the closure 10 is securely applied to the container 50, as is shown in FIG. 7, an outer annular portion of the liner 40, by virtue of its engagement with the rim 53 of the container 50, relative to the central portion of the liner 40, is maintained at a lower elevation by its contact with the projection 23 of the closure body 20, thus distorting the liner 40 and, as a result of such distortion, a resilient biasing force is created in the liner 40 that tends to bias the closure 10 upwardly from the finish 51 of the container 50 for purposes which will be subsequently described more fully.
The finish 51 of the container 50 is provided with a first series of threadlike projections 54 which are formed integrally with the finish 51 and which project radially outwardly therefrom. The threadlike projections 54 are arrayed in a circumferential pattern extending around the finish 51, and each of the threadlike projections 54 has a leading edge 54a and a trailing edge 54b. Each threadlike projection 54 extends at a helical angle with respect to the rim 53 of the container finish 51, and the threadlike projections 54 are positioned in spaced-apart or non-overlapping relationship relative to one another, with the trailing edge 54b of any given projection 54 defining an open space 54c with the leading edge 54a of the next threadlike projection 54 in the circumferential array of such threadlike projections. Together, the threadlike projections 54 form a multiple start closure receiving thread for the container 50, with each such threadlike projection 54, two of which are shown in the container of Figures 5 through 10, lying on a separate helical angle with respect to the rim 53 of the container 50. Each threadlike projection 54 is irregular in configuration, to define a generally vertically extending shoulder 54d that extends from the underside of such threadlike projection 54.
The closure body 20 of the closure 10 of the present invention also has a generally circumferentially disposed series of threadlike projections 24, which are formed integrally with the closure body 20 and which project radially inwardly from the inside of the skirt 22. Each closure threadlike projection 24 has a leading edge 24a and a trailing edge 24b and the closure threadlike projections 24 are disposed in spaced-apart or nonoverlapping relationship so that the trailing edge 24b of any particular closure threadlike projection 24 defines a space 24c with respect to the leading edge 24a of the next closure threadlike projection 24. Each closure threadlike projection 24 is irregular in configuration to define a generally vertically extending shoulder 24d that extends generally vertically upwardly from the top of such closure threadlike projection 24. The closure threadlike projections 24, each of which extends at a helical angle with respect to the rim 53 of the container to which such closure is to be applied, form a multiple start closure thread which is complementary to the multiple start container thread formed by the container threadlike projections 54, to permit the closure 10 to be applied to the container by screwing it onto the finish 51 of the container, and to be removed from the container 50 by unscrewing it from the container finish 51.
As is shown in FIG. 7, when the closure 10 is tightly applied to the container 50, the shoulder 24d of the closure threadlike projections 24 will override the shoulders 54d of the container threadlike projections 54, so that, as is shown in FIG. 8, the closure 10 can be partially unscrewed from the container 50 without the need for any special manipulation of the closure 10 to permit such partial unscrewing of the closure 10 from the container 50. As is shown in FIG. 8, during the unscrewing of the closure 10 from the container 50, a point will be reached where there is interference between each shoulder 24d of a closure threadlike projection 24 and a corresponding shoulder 54d of a container threadlike projection 54, at which time no further unscrewing of the closure 10 can occur until the shoulders 24d of the closure threadlike projections 24 are separated from the shoulders 54d of the container threadlike projections 54. As is shown in FIG. 9, the shoulders 24d can be separated from the shoulders 54d by the application of a vertically downwardly directed force on the top panel 21 of the closure 20 at locations that are aligned with the shoulders 24d of the closure threadlike projection 24, the closure top panel 21 being provided with externally apparent indicia, such as upwardly projecting, arrow-shaped projections 25, to indicate the locations for the application of such vertically downwardly directed force.
The application of vertically downwardly directed force at the arrow-shape projections 25 will downwardly depress the center of the liner 40 of the closure 10, against the upwardly directed biasing force imparted by the upper layer 42 of the closure liner 40, and upon the removal of such vertically downwardly directed force, the top panel 21 will be returned to the position shown in FIG. 8 by virtue of such biasing force in the liner 40 of the closure 10. So long as the vertically downwardly directed force against the arrow-shaped projections is sufficient to permit the separation of the shoulders 24d of the closure threadlike projections 24 from the shoulders 54d of the container threadlike projections 54, the unscrewing of the closure 10 from the container 50 can proceed to completion. The need to downwardly deflect the top panel 21 of the closure body 10 during the unscrewing of the closure 10 from the container 50 creates the need for the performance of a manipulative step which is not obvious to a child, and thereby imparts resistance to opening of the package that includes the closure 10 securely applied to the container 50, which resistance is especially effective insofar as children are concerned, and thereby it helps to prevent the accidental or inadvertent consumption of the contents P of the container 50.
The finish 51 of the container 50 also has a second series of threadlike projections, which series is made of alternating long projections 56 and short projections 57. Each short projection 56 has a leading edge 56a and trailing edge 56b and each long projection 57 has a leading edge 57a and a trailing edge 57b. The threadlike projections 56 and 57 each extend at a helical angle with respect to the rim 53 of the container 50, and generally parallel to the helically extending threadlike projections 54. As shown, the trailing edge 56b of each short projection 56 is circumferentially spaced apart from the leading edge 57a of each long threadlike projection 57, to define a space 58 between each short projection 56 and the next adjacent long projection 57. Each space 58 is so oriented around the circumference of the finish 51 as to be offset from the shoulder 54d of the adjacent threadlike projection 54, to permit the downward vertical displacement of the top panel 21 of the closure body 20 when the shoulder 24d of the closure threadlike projection 24 is in abutting contact, or interference, with the shoulder 54d of the container threadlike projection 54, and to prevent the vertical downward displacement of the shoulder 24d with respect to the shoulder 54d when such shoulders are not in abutting contact. The series of threadlike projections that include the short projections 56 and the long projections 57 defines, with a series of threadlike projections 54, a series of generally helically extending slots therebetween, which slots engage the closure threadlike projections 24 when the closure 10 is applied to the container 50. The series of container threadlike projections that includes the short projections 56 and the long projections 57 also imparts a positive lifting effect to the closure 10 when it has been unscrewed from the container finish 51 to positively lift the closure 10 from the container 50 to assist in the removal of the closure 10 from the container 50, a feature which is of particular benefit to an adult with impaired hand function due, for example, to an injury or to arthritis. When the closure body 20 is formed by injection molding, it will be in an interfering relationship with the mold plug that is used in such injection molding process, due to the presence of the shoulders 24d on the closure threadlike projections 24. Thus, it will be necessary to strip the closure body 20 from such injection molding plug, a feature which, for practical purposes, limits the use of such a closure body to a container whose finish dimension is at least 33 millimeters in diameter, or 16.5 millimeters in radius as measured from the vertical central axis of the container 50. It is also to be noted that the closure 10, because of the multiple thread start closure thread formed by the closure threadlike projections 24, will be pulled down tightly against the rim 53 of the container finish 51 at four (4) points, assuming a two-start closure thread as illustrated, to provide good balance and flatness of the closure top panel 21 when it is tightly applied to the finish 51 of the container 50. It is also to be noted that the positive lift off of the closure 10 from the finish 51 of the container 50, that is provided by the second series of closure threadlike projections that is made up of the short projections 56 and the long projections 57, will permit the substitution of a molded plug liner, if and when such a liner would otherwise be advantageous, it being noted that closures with molded plug liners are normally more difficult to remove from the associated container than closures with flat, or disk-type liners, such as the liner 40 of the closure of the present invention. Such a molded plug closure liner would make the package that includes a closure and a container of the present invention even more resistant to the spillage or leakage of the liquid contents than the closure illustrated in FIGS. 2, 3, and 4, especially when partially rotated to the position illustrated in FIG. 8. However, the springiness of the closure liner 40 should help to minimize the leakage or spillage of the liquid contents of the container 50, even when the closure 10 is partially unscrewed from the position illustrated in FIG. 7 to the position illustrated in FIG. 8. The intricacy of the design of the finish 51 of the container 50 would complicate the production of the container 50 from glass by means of a g1ass blowing operation, but such a container could be readily mass produced from various plastic compositions by means of known plastic container blow molding techniques.
Although the best mode comtemplated by the inventor for carrying out the present invention as of the filing date hereof has been shown and described herein, it will be apparent to those skilled in the art that suitable modifications, variations, and equivalents may be made without departing from the scope of the invention, such scope being limited solely by the terms of the following claims. | A liquid-tight child-resistant package that includes a glass or plastic container of the wide mouth type (i.e., with a container finish "T" dimension of at least 33 millimeters) and a complementary molded thermoplastic closure that utilizes a separate disk-type liner. The closure which, with the exception of the separate liner, is molded in one piece, has a multiple helical thread start, and each closure thread has a vertically extending shoulder on its upper side. Each complementary container finish thread has a vertically extending shoulder that engages the corresponding shoulder on the closure, after the partial unscrewing of the closure, to prevent further unscrewing of the closure until the closure is vertically depressed on the container finish, against the spring action of the closure liner, to separate the shoulder on the closure thread from the shoulder on the container thread and to thereby permit continuation of the unscrewing of the closure until it can be removed from the container. The container also has a series of threadlike projections below the container threads and the closure thread is received in helical slots between the container threads and the threadlike projections. The threadlike projections help to positively lift the closure off the container finish during the opening of the container. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to opaque coatings for electronic devices. In particular, the present invention is an opaque protective coating with primer and method of applying the coating and primer to integrated circuits and multichip modules. The coating and primer inhibit inspection and reverse engineering of integrated circuits and multichip modules.
Opaque coatings and methods of applying opaque coatings to electronic devices to inhibit inspection and reverse engineering are generally known. U.S. Pat. No. 5,399,441 to Bearinger et al. discloses one such method of forming an opaque coating on an integrated circuit. In Bearinger et al., an opaque ceramic coating is formed on an integrated circuit by a process which includes selectively applying a coating composition comprising a silica precursor resin and a filler onto the surface of the integrated circuit. A liquid mixture that includes the silica precursor resin and the filler is selectively applied to the integrated circuit by (1) masking the circuit, applying the liquid mixture and removing the mask, (2) selectively "painting" the circuit or (3) silk screening the circuit.
The coated integrated circuit is then heated at a temperature sufficient to convert the coating composition (i.e., liquid mixture) to a silica containing ceramic matrix having the filler distributed therein. Preferably, the integrated circuit with coating composition thereon is heated in a Lindberg furnace at a temperature within the range of about 50° C. to 425° C. for generally up to six (6) hours, with less than about three (3) hours being preferred, to convert the coating composition to a silica containing ceramic matrix. In Bearinger et al. the preferred silica precursor resin is hydrogen silsesquioxane resin (H-resin). To achieve a coating opaque to radiation, a filler comprising insoluble salts of heavy metals is combined with the silica precursor resin. To achieve a coating impenetrable to visual light, an optically opaque filler is combined with the silica precursor resin.
Because the method of applying the opaque coating to an integrated circuit of Bearinger et al. requires an extensive heating time period to transform the coating composition to a silica containing ceramic matrix, Bearinger et al.'s method is not particularly cost effective or efficient on a mass production level. In addition, the process of Bearinger et al. may not be usable with all types of integrated circuits since the method by which the opaque coating is applied and the extensive heating required to cure the opaque coating may cause mechanical and/or thermal damage to those integrated circuits having extremely delicate electronics. Also, the Bearinger, et al coating does not provide full protection since the liquid mixture is applied to the integrated circuit at the wafer level and before assembly of the actual devices into integrated circuit or multichip module packages. Therefore, protection is not provided for packaging components such as wire bonds, bond pads, and interconnects.
The U.S. Pat. No. 5,258,334 to Lantz, II discloses another process of applying an opaque ceramic coating to an integrated circuit. In Lantz, II, visual access to the topology of an integrated circuit is denied via an opaque ceramic produced by first mixing opaque particulate with a silica precursor. This mixture is then applied to the surface of the integrated circuit. The coated integrated circuit is then heated to a temperature in the range of 50° C. to 450° C. in an inert environment for a time within the range of one (1) second to six (6) hours to allow the coating to flow across the surface of the integrated circuit without ceramifying. The coated integrated circuit is then heated to a temperature in the range of 20° C. to 1000° C. in a reactive environment for a time in the range of two (2) to twelve (12) hours to allow the coating to ceramify. As with the above described Bearinger et al. patent, the method of applying the opaque coating of Lantz, II is time consuming and therefore not particularly cost effective or efficient on a mass production level. In addition, the process of Lantz, II may not be usable with all types of integrated circuits for the same reasons as outlined above in regards to the Bearinger et al.'s process. Likewise, as with the above described Bearinger et al. patent, the resulting coating does not provide full protection since the liquid mixture is applied to the integrated circuit at the wafer level and before assembly of the actual devices into integrated circuit or multichip module packages. Therefore, protection is not provided for packaging components such as wire bonds, bond pads, and interconnects.
There is a need for improved protective coatings for integrated circuits and multichip modules. In particular, there is a need for an improved protective coating that is both radiopaque and optically opaque to prevent inspection and/or reverse engineering of the topology of the integrated circuits and multichip modules. The protective coating should be capable of being applied to even electronically delicate integrated circuits and multichip modules without causing thermal and/or mechanical damage to the integrated circuits and multichip modules. In addition, the protective coating should be capable of being applied to integrated circuits and multichip modules in a time efficient and cost effective process to permit coating application on a mass production level. Finally, there is a need to apply the protective coatings to the wire bond and interconnects in integrated circuit and multichip module packages. These areas are unprotected using a wafer level coating.
SUMMARY OF THE INVENTION
The present invention is an opaque coating and a method of forming an opaque coating on a semiconductor integrated circuit device. To form the opaque coating on the integrated circuit device a first coating composition and a second different coating composition are prepared. The first coating composition is then applied to the surface of the semiconductor integrated circuit device to form a first coating. The second coating composition is then heated to a temperature sufficient to transform the second coating composition to a molten state. Next, the second molten coating composition is applied over the first coating on the surface of the integrated circuit device to form an opaque coating that overlies active circuitry on the surface so as to prevent optical and radiation based inspection and reverse engineering of the active circuitry.
This protective opaque coating can be applied to semiconductor integrated circuit devices, such as integrated circuits and multichip modules, in a time efficient and cost effective process to permit coating application on a mass production level. The primer coating allows the protective opaque coating to be applied to even electronically delicate semiconductor integrated circuit devices without causing thermal and/or mechanical damage to the semiconductor integrated circuit devices. Both the primer and protective opaque coating can be applied in whole or in part to assembled integrated circuit and multichip module devices including wire bonds and interconnects.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an integrated circuit or multichip module prior to the application of an organic primer coating and a protective opaque coating in accordance with the present invention.
FIG. 2 is a schematic elevational view of the protective opaque coating being applied to the integrated circuit or multichip module shown in FIG. 1.
FIG. 3 is a sectional view similar to FIG. 1 of the integrated circuit or multichip module with the organic primer coating and protective opaque coating applied thereto.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A semiconductor integrated circuit device, such as an integrated circuit (IC) or multichip module (MCM) 10 to be coated in accordance with the present invention is illustrated generally in FIG. 1. The IC or MCM 10 includes a single, active circuitry semiconductor chip 12 (in the case of an IC) or multiple, active circuitry semiconductor chips 12 (in the case of a MCM). The semiconductor chip(s) 12 is mounted on a surface 13 of a substrate 14 and includes lead wires 16 that are connected to pads 18 also mounted on the surface 13 of the substrate 14. The pads 18 serve as ports for electrical connection to external sources (not shown). The substrate 14 with the chip(s) 12 and pads 18 mounted thereto is housed within a ceramic package 20 defined by a base member 22, a lid member 24 and a lid seal 26 (the lid member 24 and lid seal 26 not being shown in FIG. 1.).
The IC or MCM 10 of FIG. 1, in accordance with the present invention, is first coated with an organic based film, primer coating 15 (see FIG. 3) that is applied by way of reactive vacuum deposition, thermal spray or liquid coating process. Before the primer coating 15 is applied, a primer coating composition that defines the primer coating 15 is prepared. The primer coating composition is prepared from chemical materials that are compatible with the materials from which the IC or MCM 10 is manufactured. In the present invention, the primer coating composition may be Parylene, a solid thermoplastic, a solid siloxane or a furfural based liquid polymer. In one preferred embodiment, the primer coating composition is Parylene. In another preferred embodiment, the primer coating composition is siloxane. Once prepared, the primer coating composition is applied to the IC or MCM 10 devices using reactive vacuum deposition for Parylene, thermal spray deposition (as described later) for thermoplastic and siloxanes and liquid drop deposition for the furfural based polymer. As seen in FIG. 3, the formed primer coating 15 completely covers the semiconductor chip(s) 12, lead wires 16, pads 18 and the surface 13 of the substrate 14 housed within the base member 22. However, the primer 15 may be applied so as to only partially or completely cover any one of or more of the semiconductor chip(s) 12, leads 16, pads 18 and/or surface 13. In the present invention, once formed, the primer coating 15 has a thickness within the range of 0.1 mils to 2 mils. In one preferred embodiment, the formed primer coating 15 has a thickness of 0.7 mils.
After the primer coating 15 is applied and allowed to form (i.e., cure), the IC or MCM 10 is then coated with a protective opaque coating 28 (see FIG. 3) by a thermal spray process 29 illustrated in FIG. 2. The thermal spray process 29, of the present invention, is a line of sight coating process that includes a thermal spray gun 30 having a nozzle 31. A heat energy source 32 is delivered to the nozzle 31 (in a known manner) to heat a ceramic particle based coating composition 33 also delivered to the nozzle 31 (in a known manner). The heat energy source 32 uses a flame 34 to heat the coating composition 33 to a molten state defined by molten liquefied particles 35. The molten liquefied particles 35 defining the coating composition 33 are carried to the IC or MCM 10 by a carrier gas jet 36 also delivered to the nozzle 31 (in a known manner). The IC or MCM 10 is supported on a support element 38 that may act as heat sink during the coating process.
The primer coating 15 is applied before the protective opaque coating 28, to improve the resistance of the IC or MCM 10 to mechanical and/or thermal damage that may result from the molten liquefied particles 35 being driven toward the IC or MCM 10 (via carrier gas jet 36) and impacting the IC or MCM 10 at a high velocity. The primer coating 15 is provides protection particularly when the IC or MCM 10 is electronically delicate. For example, when the IC or MCM 10 has thin lead wires 16, weak bonding joints between the lead wires 16 the pads 18 and semiconductor chip(s) 12, and/or when the circuit architecture of the IC or MCM 10 is susceptible to thermal shock or impingement damage.
The thermal spray process 29 first requires the preparation of the ceramic particle based coating composition 33. It is desirable that the chemistry of the coating composition 33 (as well as the primer coating composition) be similar to the chemistry of the materials of the IC or MCM 10, such that attempted removal of the protective opaque coating 28 (formed from the coating composition 33) and the primer coating 15 from the IC or MCM 10 (for inspection and/or reverse engineering of the topology of the IC or MCM) via chemical methods will simultaneously destroy the IC or MCM 10. In the present invention, the coating composition 33 may be a single chemical component or a multi chemical component composition, partially or entirely formed from any one of alumina, beryllia, silica, silicon carbide, aluminum nitride, fused alumina-titanium oxide, fused alumina titanium dioxide and nylon, alumina titanium oxide and teflon, barium titanate, or other ceramic oxides or silicates. In one preferred embodiment fused alumina-titanium oxide was found to provide a desirable coating composition 33 for the protective opaque coating 28.
The coating composition 33 is prepared by manufacturing the chemical materials of the coating composition 33 into a powder or sintered rod having particle sizes within the range of ten microns to sixty microns. Particle sizes in excess of sixty microns tend to cause mechanical damage to the IC or MCM 10 due to that force at which the carrier gas jet 36 delivers the molten liquefied particles 35 to the IC or MCM 10. Particle sizes less than ten microns tend to cause transformation of the particle based coating composition 33 into a liquid stream (rather than molten liquefied particles 35) that may be difficult to control during the application process. In one preferred embodiment, a coating composition 33 prepared in the form of a sintered rod with the coating composition 33 having a particle size within the range of ten microns to twenty microns is desirable.
Once the coating composition 33 is prepared, the coating composition 33, the heat energy source 32 and the carrier gas jet 36 are simultaneously delivered to the nozzle 31 of the thermal spray gun 30. The heat energy source 32 can take the form of a plasma arc, an electric arc or a fuel gas. In one preferred embodiment, the heat energy source is a fuel gas 40 (preferably acetylene) which is combined with oxygen 42 to create that flame 34 that is of a temperature sufficient to transform the ceramic particle based coating composition 33 to molten liquefied particles 35. In one preferred embodiment, this temperature is in the range of between 200° C. and 3000° C. The molten liquefied particles 35 are applied to the IC or MCM 10 over the primer coating 15 via the carrier gas jet 36 which carries the molten liquefied particles 35 to the IC or MCM 10 and causes the particles 35 to impact upon the IC or MCM 10. The molten liquefied particles 35 undergo a "splat" upon impact with the surface of the IC or MCM 10, and then coalesce to form a contiguous coating that thickens with continued successive depositions of the molten liquefied particles 35 to form the lamellar protective opaque coating 28. In one preferred embodiment, the carrier gas jet 36 is pressurized nitrogen which is delivered to the nozzle 31 of the thermal spray gun 30 in the range 10-100 cfm.
As seen in FIG. 2, in practice, the nozzle 31 of the thermal spray gun 30 is positioned above the IC or MCM 10 which is held in place by the support element 38 which can draw heat away from the IC or MCM 10 during the application process. Typically, the nozzle 31 is positioned from the IC or MCM 10 within the range of between five inches and seven inches. In one preferred embodiment, the nozzle 31 is positioned six inches from the IC or MCM 10. The molten liquefied particles 35 can be applied over the primer coating 15 in successive layers or as a single burst depending upon the desired coating thickness and the thermal limitations of the IC or MCM 10. In one preferred embodiment, the thickness of the formed protective coating 28 is in the range of between 0.1 mil and 200 mils. The molten liquefied particles 35 are applied by moving the nozzle 31 of the thermal spray gun 30 back and forth over the surface of the IC or MCM 10, by moving the IC or MCM 10 relative to the nozzle 31, or by moving both the nozzle 31 and the IC or MCM 10 relative to one another. In one preferred embodiment, the nozzle 31 is moved relative to a stationary IC or MCM 10.
Once the molten liquefied particles 35 are applied over the primer coating 15, they form a lamellar protective opaque coating that adhesively bonds to the surface of the IC or MCM 10 and is abrasion resistant, provides a hermetic seal, and prevents both active and passive, chemical, optical and radiation based inspection and/or reverse engineering of the active and inactive circuitry of the IC or MCM 10. As seen in FIG. 3, the formed protective opaque coating 28 completely covers the semiconductor chip(s) 12, lead wires 16, pads 18 and the surface 13 of the substrate 14 housed within the base member 22. However, the protective, opaque coating 28 may be applied so as to only partially or completely cover any one of or more of the semiconductor chip(s) 12, leads 16, pads 18 and/or surface 13. Once the protective opaque coating 28 is formed, the lid seal 26 and the lid member 24 are mounted on the base member 22 to further hermetically seal the IC or MCM 10.
The primer coating composition can be applied and cured to the primer coating 15 (to achieve complete coverage as shown in FIG. 3) in 1 to 60 minutes. The molten liquefied particles 35 can be applied over the primer coating 15 on the surface of the IC or MCM 10 (to achieve complete coverage as shown in FIG. 3) in 15 to 600 seconds. The protective opaque coating 28 can be fully coated and cooled and the IC or MCM 10 ready for use in only 1 to 70 minutes. Therefore, the thermal spray process is capable of producing inspection and/or reverse engineering proof IC's or MCM's 10 in a time efficient and cost effective manner that permits coating application on a mass production level.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | Disclosed is a method of forming a primer coating and an opaque coating on an integrated circuit or multichip module. First a primer coating composition is applied to a surface of the integrated circuit device or multichip module to form a primer coating that increases the resistance of the surface to thermal and mechanical damage that may occur as a result of the application of the opaque coating. An opaque coating composition is then heated to a molten state and the molten opaque coating composition is applied over the primer coating to form an opaque coating that overlies active circuitry on the surface, to prevent optical and radiation based inspection and reverse engineering of the active circuitry. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to humidification systems which are used in heating, ventilating and air conditioning (HVAC) systems. Specifically, this invention relates to an improved apparatus for introducing steam into an airstream in such a system.
2. Description of the Prior Art
Air that contains an inadequate amount of humidity can cause problems that range in severity from merely annoying to extremely expensive or even life threatening. Dry air can make people more susceptible to colds, sore throats and other respiratory problems. It can draw moisture out of materials such as carpet, wood, paper, leather, vinyls, plastics and foods. It can also contribute to the generation of static electricity, which can damage electronically sensitive tapes and disks.
Most modern commercial and industrial buildings are equipped with steam humidifiers mounted within the heating and air conditioning systems. Steam from a steam boiler or district steam system is introduced into the ductive airstream and distributed throughout the building. Humidification steam cannot be allowed to condense into water in a duct system. Damp areas in ducts become breeding grounds for algae and bacteria, many of which are disease-producing to humans, contaminating to industrial processes, and so forth.
To prevent condensation in the duct the steam must be totally absorbed by the air before the air carries the steam into contact with any internal devices such as dampers, fans, turning vanes etc., within the duct. The more thoroughly the steam is mixed with the air, the shorter the distance it will travel within the duct before becoming absorbed by the air.
Some duct configurations, due to structural limitations imposed by the building design, have very limited open space downstream of the humidifier for absorption of the steam. Closely spaced multiple steam dispersing tubes provide the degree of mixing of steam and air necessary to satisfy those jobs at the present time.
Steam humidifier dispersion tubes can present two operational difficulties when installed in a closely spaced arrangement. Present day steam dispersion tubes are usually constructed with a hot outer jacket which contains steam. The purpose of this is to keep the tube hot, thus preventing condensation from the humidification steam forming as it passes through the tube. In closely spaced multiple tube arrangements, such a configuration can present an impediment to air flow within the ducting system. Even more importantly, such configurations often add unwanted heat to the airstream due to the exposed outer surface of the hot jacketing adding an unnecessary refrigeration load during periods of cooling. Insulating the exterior surfaces of the hot jacketing can reduce the heat gain, but further aggravates the air flow resistance problem. An automatic valve can be placed in the steam line supplying steam to the tube jackets and cycling it off and on with the humidifier steam valve. When this has been done in many cases the flexing of the tubes due to flexing caused by heating and cooling has led to eventual cracking of jacket welds.
It is clear there has existed a long and unfilled need in the prior art for a steam injection humidification system that is unaffected by condensation problems, and that is capable of introducing humidity into an airstream consistently and effectively.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a steam injection humidifier that is largely unaffected by condensation problems.
It is further an object of this invention to provide a steam injection humidification system that is more consistent in introducing humidity into an airstream than those which are heretofore known.
It is yet further an object of the invention to provide a steam injection humidifier which accomplishes improved performance while eliminating the attendant problems of resistance to air flow and unwanted heat gain to the airstream.
It is also an object of the invention to provide an injection-type steam humidification system which provides improved mixing action of steam and air over those systems which are presently known.
In order to achieve these and other objects of the invention, an apparatus for introducing steam into an airstream in an HVAC humidification system according to the invention may include a supply header which is adapted for connection to a source of steam; steam dispersion structure positioned downstream of the supply header for receiving steam from the supply header and for dispersing a percentage of such steam into an airstream; and structure for collecting excess steam and condensation from the steam dispersion structure, the collecting structure being adapted for connection to a fluid drain, whereby condensation is effectively removed from the apparatus without escaping into the airstream or associated elements of an HVAC system.
According to another aspect of the invention, an apparatus for introducing steam into an airstream in an HVAC humidification system includes at least one tube having a first inlet end which is adapted to be connected to a source of steam and a second outlet end which is adapted to be connected to a liquid and steam collecting structure; the tube having a plurality of radial holes defined therein; a plurality of nozzles inserted, respectively, in the radial holes, the nozzles each having an axial bore defined therein for conducting steam away from the tube into an airstream; and fender structure connected to an upstream side of the tube for insulating the tube against unwanted heat transfer from the tube to the airstream, whereby condensation within the tube is kept to a minimum, and resistance to airflow is minimized within the duct.
According to another aspect of the invention, an apparatus for introducing steam into an airstream includes a supply header which is adapted to be connected to a source of steam, the supply header having an outer wall defining a space therein; and a dispersion tube having at least one nozzle therein for dispersing steam into an airstream, the tube having a first end which extends through the outer wall for a distance into the space, thereby forming a collection space in the supply header in which condensation may collect.
These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of an HVAC humidification system constructed according to a preferred embodiment of the invention;
FIG. 2 is a partially schematic diagram depicting a portion of the system illustrated in FIG. 1;
FIG. 3 is a fragmentary cross-sectional view taken along 3-3 in FIG. 2;
FIG. 4 is an enlarged fragmentary crosssectional view taken through one of the dispersion tubes depicted in FIG. 2;
FIG. 5 is a diagrammatical view depicting a feature of the embodiment shown in FIGS. 1-4;
FIG. 6 is a diagrammatical view which corresponds to the view of FIG. 5 and depicts a second embodiment of one aspect of the invention;
FIG. 7 is a fragmentary cross-sectional view of a second embodiment of a second aspect of the invention; and
FIG. 8 is a fragmentary cross-sectional view of a third embodiment of the second aspect of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to Figure 1, an improved HVAC humidification system 10 includes a multiple tube dispersion unit 12 that is secured so as to be partially within an HVAC duct 14 by one or more mounting members (not shown) which are of conventional design. A steam supply line 16 is provided from an external source, such as an in-house boiler or district steam system.
Referring again to FIG. 1, the direction of air flow within duct 14 is indicated by the arrows. To provide improved, consistent mixing action of steam and air, a perforated diffuser plate is positioned in duct 14 slightly upstream from the multiple tube dispersion unit 12. In the preferred embodiment, diffuser plate 15 is a flat plate containing a plurality of evenly spaced perforations or holes 17. In operation, pressure builds up on the upstream side of diffuser plate 15. The constant pressure allows air to escape through each of the evenly spaced holes 17 at a common flow rate. Since holes 17 are spaced evenly over the surface of diffuser plate 15, the air flow immediately upstream of dispersion unit 12 is thus constrained to be substantially even and constant over the entire cross section of duct 14. As a result, an even steam-to-air mixing takes place at the plane within duct 14 at which dispersion unit 12 is located.
Referring now to FIG. 2, steam from supply line 16 is supplied to dispersion unit 12 via a steam line 19. A control valve 26 is interposed in steam dispersion line 19 for regulating the amount of steam that is allowed to flow into dispersion unit 12. A control system 27, the details of which will be known to those skilled in the art, is arranged so as to selectively open or close control valve 26.
Referring again to FIG. 2, dispersion unit 12 includes a longitudinally extending supply header 28 which is connected at a first end 29 to steam line 19. The first end 29 of supply header 28 is elevated with respect to a second, opposite end 31. As a result, the longitudinal axis of supply header 28 is inclined with respect to a horizontal plane 30 at an angle A, as may be seen in Figure 2. As a result, any condensation which forms within supply header 28 is caused to drain toward second end 31. It should be understood that header 28 could be vertical if tilted at a different angle to achieve the same effect.
Dispersion unit 12 includes a steam dispersion portion 33 that is constructed of a plurality of elongate tubes 32. In the preferred embodiment, the tubes 32 are mounted so that their longitudinal axes are substantially vertical and parallel to each other. Alternatively, however, they could be tilted at another, lesser angle with respect to the horizontal, as long as the second end position is beneath first end portion 42. Each of the tubes 32 are connected at a first end portion 42 to supply header 28, and at a second end portion to a return header 34. The preferred construction of tubes 32 will be described in greater detail below.
As may be seen in FIG. 2, return header 34 extends longitudinally between a first end 35 and a second, opposite end 37. First end 35 is elevated with respect to second end 37. As a result, the longitudinal axis of return header 34 is inclined with respect to a horizontal plane 30 by an angle B, as is shown in FIG. 2. Angle A is preferably the same or greater than Angle B. Condensation in return header thus tends to flow toward second end 37 and into a steam trapping device which in the preferred embodiment is a standard steam trap 36 of the type which is well known in the art, which is connected to second end 37. A drain line 38 is provided to conduct condensate from steam trap 36, as may be seen in FIG. 2.
Looking again to FIG. 2, a condensation drain line 40 is provided to guide condensed water from the second end 31 of supply header 28 to the second end 37 of return header 34, and thus into steam trap 36.
Referring now to FIG. 3, the first end portion 42 of each of the tubes 32 extends through an outer wall of supply header 28 for some distance into a space which is defined within the supply header 28. Preferably, supply header 28 is circular in cross-section, and the first end portion 42 terminates in a plane which contains the longitudinal axis of supply header 28, as is shown in FIG. 3. Since first end portion 42 extends for some distance into the supply header 28, a collection space 44 is formed in a lower half of supply header 28 in which condensation may collect. As a result, the condensation is prevented from entering the tubes 32. The collected condensation 46 is shown in FIG. 3. Condensation 46 will flow toward the second end 31 of supply header 28 due to the inclination of supply header 28, and into the condensation drain line 40 as has previously been described.
As may be seen in FIG. 4, a plurality of vapor nozzles 48 are mounted within holes defined radially in the outer wall of each of the tubes 32. Each of the vapor nozzles 48 have an orifice defined therein for allowing a predetermined flow rate of vapor to pass therethrough at a given input pressure. In a first embodiment which is shown in FIG. 5, nozzles 48 are positioned with respect to the respective tubes 32 so that the bores therein are substantially aligned along a plane which contains the longitudinal axes of the parallel tubes 32. The direction of the air flow is shown in FIG. 5 by an arrow.
As shown in FIG. 4, the nozzles 48 protrude well inwardly of the inside cylindrical surface, preferably to the center, of the respective tubes 32. As a result, the condensation that forms and will naturally adhere to the inside surfaces of tubes 32 will drain downwardly along the inside surface and into the return header 34, rather than being expelled into the airstream through the nozzle 48. This feature of the invention, in conjunction with the structure that is described above with regard to FIG. 3, ensures that condensation is efficiently drained from the unit rather than escaping into the airstream that is to be humidified.
In a second embodiment which is illustrated in FIG. 6, the nozzles 48 are located so that their axial bores are positioned at an acute angle with respect to the plane which contains the longitudinal axes of the tubes 32. The nozzles 48 are positioned on the side of the tubes 32, which is downstream from the direction of the air flow, as it is indicated by the arrow in FIG. 6. Preferably, the nozzles 48 on each of the tubes 32 are symmetrical with respect to the direction of the air flow, which in FIG. 6 is substantially perpendicular to the plane containing the longitudinal axes of tubes 32. In practice, the embodiment shown in FIG. 5 is better suited for use in systems having a relatively high velocity air flow. Conversely, the embodiment shown in FIG. 6 is better suited for use in systems having a lower air flow velocity.
Another important feature of the embodiment of the invention which is illustrated in FIG. 6 is the provision of wedge-shaped fenders 33 on the upstream side of each of the tubes 32. In the embodiment which is illustrated in FIG. 6, each fender 33 is formed by a pair of plates 35 which are joined to each other at a first end, and are fastened to opposite sides of a tube 32 on a second end thereof. The plates 35 thus create a dead air space 37 which provides insulation against heat transfer between the airstream and the tube 32. As a result, a dispersion tube 32 having a fender 33 mounted thereon will transmit less heat to the airstream than it would without the fender 33, while still being able to inject steam into the airstream through nozzles 48. A secondary benefit of the diminished heat transfer between tubes 32 and the airstream with the provision of fenders 33 is that less condensation will occur within the tubes 32, thereby improving the overall efficiency of the system. The fenders 33 also serve to streamline the cross-section of the tube relative to the direction of air flow, thus decreasing air flow resistance. Although the fenders 33 are illustrated only with respect to the embodiment of the invention which is shown in Figure 6, it is to be understood that such fenders could likewise be used in the embodiment shown in FIG. 5, or in other, equivalent embodiments according to the spirit of the invention.
Referring now to FIG. 7, a second embodiment 60 of an improved HVAC humidification system includes a supplier header 62 and a return header 64 which are mounted externally of a vertically-extending HVAC duct 14. As may be seen in FIG. 7, return header 64 is positioned at a level that is beneath the level at which supplier header 62 is positioned. As a result, the plurality of elongate steam dispersion tubes 66 which extend between supply header 62 and return header 64 are inclined with respect to a horizontal plane H at an angle C. As a result, condensation within the elongate tube 66 is caused to run downwardly into the return header 64, which is connected to a drain pipe in the manner shown in FIG. 2. Preferably, supply header 62 and return header 64 are both slightly inclined with respect to the horizontal plane H, so that condensation therein can be collected and drained in the manner that is shown and described with respect to Figure 2. The system illustrated in FIG. 7 is identical in all other aspects to that shown in FIGS. 1-5.
Looking now to FIG. 8, an improved HVAC humidification system 67 constructed according to a third embodiment of the invention includes a supply header 68 and a return header 70, both of which are positioned within a vertically-extending duct 14. An elongate tube 72 extends from supply header 68 to return header 70. Supply header 68 is elevated with respect to return header 70, and elongate tube 72 thus is inclined with respect to a horizontal plane H at an angle C. The system 67 illustrated in FIG. 8 is identical in all other respects to the system 60 which has previously been shown and described with respect to FIG. 7. Generally, the system illustrated in FIG. 7 is preferable for use in vertically-extending ducts wherein sufficient external space is available to accommodate supply header 62 and return header 64.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extend indicated by the broad general meaning of the terms in which the appended claims are expressed. | An improved apparatus for introduicng steam into an airstream in a heating, ventilating and air conditioning system includes a supply header, steam dispersing structure and structure for collecting condensation from the steam dispersing structure. The supply header is adapted for connection to a source of steam and is preferably elevated with respect to the return header, so that condensation in the supply header is forced into the return header under the influence of steam pressure and gravity. Both headers may further be inclined to improve drainage of condensation. The invention optionally may utilize fenders in conjunction with the steam dispersing structure to minimize heat transfer to the airstream. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to the field of centrifuges. More particularly, the invention comprises a device for removing hard sludge automatically from the interior of a centrifuge basket.
In a basket centrifuge, a liquid containing solid material is directed into a rapidly rotating basket. As the basket spins, the solid particles in the liquid migrate to the basket wall, due to centrifugal force. As more and more liquid/solid mixture is added to the basket, the clarified liquid overflows the sides of the basket, while the solid material remains trapped along the basket wall. The clean liquid is then recovered by suitable collecting means outside the basket.
After prolonged use of the centrifuge, there is a substantial accumulation of solid material along the basket wall. This material, referred to generally as "sludge", reduces the efficiency of the centrifuge by occupying space that would otherwise be filled with liquid. The sludge must therefore be periodically removed in order to enable the centrifuge to process additional liquid at the normal rate.
Sludge is generally classified in two groups. There is the socalled "soft" or gelatinous sludge, such as that which results from the separation of impurities from several industrial processes, such as electroplating, degreasing, or paint spraying. The other kind of sludge is "hard" sludge, which results from metal fines, glass fines, sugar crystals, and the like. This invention is directed to the special problems associated with hard sludge.
Soft sludge may be conveniently removed from a centrifuge basket by introducing a discharge tube into the centrifuge while the basket is spinning. The relative motion of the basket and the tube causes the soft sludge to be extruded through the tube, and discharged into an appropriate collection container. The tube need only be moved radially, i.e. towards and away from the rim of the basket. The tube need not be moved vertically within the basket, since the soft sludge will migrate in a vertical direction towards the tube.
Hard sludge is not as easily removed from a centrifuge. Not only does hard sludge tend to clog the discharge tube, but it becomes firmly packed along the basket wall, and does not migrate vertically to the location of the tube. The simple expedient of using a single discharge tube, which is satisfactory for soft sludge, will not work satisfactorily for hard sludge.
The problem of removing solid particles from centrifuge components has been addressed in various ways in the prior art. For example, U.S. Pat. No. 3,682,310 shows a centrifuge having a filter disposed therein. A stream of air is periodically directed against the filter to loosen particles which have accumulated on the filter element. U.S. Pat. No. 4,000,074 shows a centrifuge wherein dried particles of explosive material fall out of the centrifuge by gravity. U.S. Pat. No. 2,206,401 uses a spray means directed into the centrifuge basket, apparently to inject a washing agent into the apparatus. U.S. Pat. No. 614,764 shows a centrifuge for separating sugar syrup from sugar crystals, wherein the crystals are removed from the bottom of the apparatus. U.S. Pat. No. 3,311,240 shows another sugar centrifuge, including a spray means for washing or coating the solid particles.
Nothing in the known prior art teaches a satisfactory automatic method for removal of hard sludge. The only known prior art technique for automatically scraping hard sludge from the basket wall requires actuated blades to "plow" the material loose. This technique is a slow-speed process, and requires high power. In addition to the need for specialized drive components, this prior art technique requires parts which wear rapidly, due to the abrasive character of the sludges.
The only alternative to the above-described technique has been manual cleaning. It has been necessary to stop the centrifuge, remove the basket, and replace it with a spare basket, while the original basket is cleaned by hand. This procedure is cumbersome and inefficient. Not only is it difficult to remove the sludge manually, but the method requires that the system be stopped every time a cleaning is necessary.
The present invention provides an apparatus which overcomes the above-described difficulties in removing hard sludge from a centrifuge. The invention requires only minimal contact with the abrasive sludge, in the re-slurrying process. The invention also comprises a method of removing such sludge. By use of the present invention, sludge may be removed from a centrifuge basket without manual cleaning, and without stopping the entire system. The invention may be used to remove many different kinds of hard sludge, having different degrees of hardness.
SUMMARY OF THE INVENTION
In its simplest form, the present invention comprises two tubes disposed within the centrifuge basket. One tube is a sludge reslurrying tube, and the other is a sludge discharge tube. The discharge tube and re-slurrying tube can be connected, through appropriate valves, to form a closed loop, so that fluid entering the discharge tube is recirculated into the centrifuge through the re-slurrying tube. The re-slurrying tube terminates in a nozzle, or spray slot, which is pointed in the general direction of the sludge discharge tube. The end of the discharge tube is curved, so that the opening at its end is tangential to the oncoming flow of liquid. The recirculated fluid is thereby directed, at high velocity, at the sludge deposits on the basket wall and back into the discharge tube. The spray therefore causes the sludge to become at least partially mixed into a slurry, and tends to maintain a uniform distribution of liquid and solid material.
Periodically, the recirculation path from the discharge tube to the re-slurrying tube is closed off, by a suitable valve, and the slurry entering the discharge tube is then withdrawn from the apparatus. Additional liquid, either process liquid or liquid from a separate source, is then added to the centrifuge basket, to compensate for the loss of liquid in the slurry, and to facilitate the sludge removal process.
The sludge discharge tube and sludge re-slurrying tube are mechanically linked, and rotate together. Rotation of these tubes causes the nozzle and the curved portion of the discharge tube to assume varying radial positions within the centrifuge basket. The tubes are configured so that the discharge tube always leads the reslurrying tube. That is, the curved end of the discharge tube is always closer to the wall of the basket than is the nozzle of the reslurrying tube. When the discharge tube reaches the vicinity of the wall of the basket, virtually all of the sludge has been removed, and the cleaning process is complete.
The apparatus includes a plurality of valves which direct the flow of fluids into the proper channels. Operation of these valves causes the recirculation path from the discharge tube to the reslurrying tube to be opened or closed, and also controls the flow of fluids into and out of the entire apparatus. The valves, and the motor (or hydraulic cylinder, or other device) which rotates the tubes, are actuated by timers which are pre-programmed according to the type of sludge being removed.
In another embodiment, the tubes are pre-programmed to pause at various points along their path of travel, so that the slurry in the basket may be discharged. The pre-programming may be accomplished by a plurality of cams which actuate a switch. The switch then signals a microprocessor, which initiates the sequence of valve openings and closings necessary to remove the slurry from the basket.
In another automatic embodiment, the tubes are programmed to stop for discharge of the slurry whenever the tubes encounter resistance to movement, due to the presence of a wall of hard sludge. Resistance to movement may be detected by measuring the current in a drive motor, the current tending to increase rapidly when the tubes encounter resistance. Instead of measuring motor current, the apparatus can measure the pressure drop between the re-slurrying and discharge tubes. When the viscosity of the slurry reaches a predetermined level, the pressure drop will increase beyond a corresponding level, causing the apparatus to initiate the slurry discharge cycle. In this automated embodiment, there is no need to make an accurate prior estimate of the time needed for desludging.
When desludging is completed, the sludge discharge tube and sludge re-slurrying tube may be rotated into the inoperative position, near the center of the basket, in the region which contains no liquid while the basket is spinning. Thus, the desludging apparatus does not interfere with normal centrifuging operations. The entire apparatus may therefore be programmed to cycle through centrifuging and desludging procedures, without the need for manual cleaning or for other manual control.
It is therefore an object of the present invention to provide apparatus for automatic removal of hard sludge from a centrifuge.
It is another object of the invention to provide apparatus as described above, wherein the centrifuge need not be stopped in order to remove the sludge.
It is another object of the invention to provide apparatus as described above, wherein the apparatus may be operated by preprogrammed timers, to remove sludges of a known hardness.
It is another object of the invention to provide apparatus as described above, wherein the apparatus automatically determines the required rate of desludging, according to the sensed hardness of the sludge.
It is another object of the invention to provide apparatus as described above, wherein the apparatus automatically determines the required rate of desludging, according to the sensed viscosity of the slurry within the centrifuge.
It is another object of the invention to provide apparatus as described above, wherein the sludge removal apparatus can rest within the centrifuge basket while not in use, without interfering with normal operation of the centrifuge.
It is another object of the invention to provide apparatus as described above, wherein the apparatus permits the addition of process liquid, or other liquid, into the centrifuge to facilitate the desludging operation.
It is another object of the invention to provide an apparatus for practicing a method for automatic removal of hard sludge from a centrifuge.
Other objects and advantages of the invention will be apparent to those skilled in the art, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic, partial perspective view of the lid of the centrifuge, showing the sludge discharge and sludge reslurrying tubes, made according to the invention.
FIG. 1A is a detail of the nozzle of the sludge reslurrying tube, showing an alternative construction of the nozzle.
FIG. 2 is a cross-sectional view of the basket of a centrifuge, showing the sludge discharge and re-slurrying tubes inserted therein.
FIG. 3 is a cross-sectional view taken along the lines 3--3 of FIG. 2.
FIGS. 4A and 4B illustrate a partially schematic top view of an alternative embodiment, wherein the desludging is automated, through use of a rotating gear.
FIG. 5 is a schematic diagram illustrating the means of control of the desludging device in the various automated embodiments.
FIG. 6 is a flow diagram illustrating the steps required in automatically controlling the desludging process.
FIG. 7 is a schematic diagram of an alternative automatic embodiment, wherein the apparatus determines when the slurry needs to be discharged, based on a measurement of differential pressure.
DETAILED DESCRIPTION OF THE INVENTION
The major features of the invention are illustrated in FIG. 1. FIG. 1 shows sludge discharge tube 9 and sludge re-slurrying tube 12, mounted within lid 1 of the centrifuge. The re-slurrying tube terminates in nozzle 7 having spray slot 8. Both the re-slurrying tube 12 and the discharge tube 9 can be rotated in either direction around their axes, as indicated by arrows 11 and 13. The discharge tube 9 has a curved end portion, the end portion being disposed in a generally horizontal position, with respect to the centrifuge basket. Thus, opening 2 of discharge tube 9 faces into the flow of liquid within the spinning basket.
Slot 8 of nozzle 7 is narrow enough to create a high-velocity flow out of the slot, but is wide enough to allow the passage of particulate matter without clogging the slot. An alternative construction for the nozzle is shown in FIG. 1A. In this embodiment, the nozzle comprises a plurality of holes 65, instead of the slot 8 of FIG. 1. It is understood that still other kinds of nozzles may be used, within the scope of this invention. What is important is that liquid be directed, at high velocity, out of the nozzle, and in the general direction of the accumulated sludge and the discharge tube.
The sludge re-slurrying tube 12 and sludge discharge tube 9 are made to rotate together by link 21. Rotation is accomplished by piston means 19, which creates motion in the direction indicated by arrow 15. The piston means 19 may be hydraulic or pneumatic. The tubes may also be rotated electrically, by a conventional motor, or even manually. The position of the tubes is biased by spring 17.
Instead of moving the tubes by a piston, the tubes can also be driven directly, by a suitable motor attached to the tube. In this case, spring 17 would be omitted.
It is seen from the drawings that when tubes 9 and 12 are rotated, the nozzle 7 and the open end 2 of discharge tube 9 move radially within the centrifuge basket. Thus, the tubes 9 and 12 can traverse substantially the entire region containing the sludge.
The re-slurrying tube 12 and the discharge tube 9 are the critical components for removal of hard sludge. The tubes 12 and 9 together comprise a loop, by virtue of valve 27, so that liquid entering the discharge tube 9 is recirculated through the re-slurrying tube 12. The liquid exits nozzle 7 at high velocity, and the liquid impinges on the boundary of hard sludge, causing that sludge to become loosened, and mixed more uniformly with the liquid. The resulting slurry is more easily withdrawn from the apparatus, through valve 29.
After some slurry has been removed from the apparatus, it is usually necessary to add more liquid to the basket to continue the desludging process. Liquid can enter the apparatus through conduit 3, passing through valve 25 and into pipe 5 which comprises the upper portion of sludge re-slurrying tube 12. The liquid entering at conduit 3 may be either the process liquid, i.e. the liquid which is to be purified in the centrifuge, or a solvent or other liquid from another source.
During the desludging operation, process liquid does not flow into the centrifuge, except for the liquid which is introduced intermittently, as described above. At all other times, i.e. while the centrifuge is being operated normally, process liquid can be brought into the centrifuge through an independent channel, separate from the desludging portion of the apparatus. Conduit 4, controlled by valve 23, represents this separate entry means, and is the preferred construction. It is possible, however, to design the system so that the process liquid enters the centrifuge through the re-slurrying tube.
It is noted that, in FIG. 1, the functions of discharging the slurry from the apparatus and recycling the slurry back to the reslurrying tube are performed by the same tube. These functions can also be performed by separate tubes. It is therefore understood that the term "discharge tube", as used herein, means a tube for discharging the slurry from the interior of the centrifuge, whether or not that tube leads the slurry out of the apparatus entirely, or conveys it back through a re-slurrying tube.
FIG. 2 is a cross-sectional view showing the sludge reslurrying tube 12 and the sludge discharge tube 9 inserted into the centrifuge basket 40. The basket 40 is shown rotating in the direction indicated by the arrow, the rotation being imparted by driving hub 45. Basket 40 has a lip 43 which defines a region within which liquid can be retained in the centrifuge. Arrows 49 and 50 represent symbolically the introduction of process liquid into the system. Arrows 49 and 50 thus represent the flow of liquid coming from conduit 4 of FIG. 1. The solid particles in the liquid adhere to the side wall 60 of basket 40, due to centrifugal force, and the clean liquid exits the basket by overflowing the lip 43. Diffuser 52 distributes the liquid/solid slurry evenly around the perimeter of the basket 40. The diffuser 52, however, is not an essential element of the invention.
In FIG. 2, the entire region defined by lip 43 is shown filled with liquid and/or sludge. The central region, i.e. the region within the basket 40 which is not directly under lip 43, is essentially free of liquid while the basket is spinning, except for the liquid being introduced into the centrifuge.
FIG. 2 shows a large accumulation of sludge 54 along the wall 60 of basket 40. The liquid within the centrifuge, and adjacent the sludge 54, is indicated by reference numeral 56. In FIG. 2, the sludge 54 occupies about three-quarters of the radial distance from the basket wall 60 to the inner edge of lip 43. The figure thus shows a centrifuge which has need of desludging.
It is noted that the discharge tube and re-slurrying tube do not move vertically. Because all of the sludge is re-slurried, the sludge will migrate, up or down, to the location of the discharge tube, in a manner similar to that encountered with soft sludge.
The cross-sectional view of FIG. 3 illustrates the movements of the sludge re-slurrying tube 12 and the sludge discharge tube 9. In FIG. 3, as in FIG. 2, the centrifuge basket 40 is shown spinning, in the direction shown by arrow 73. Also visible are sludge 54 and liquid 56.
The tubes 12 and 9 are rotatable around axes 80 and 81, as shown by arrows 74 and 75. Reference numerals 70 and 71 indicate, in phantom, the fully retracted positions of tubes 12 and 9, respectively. Due to their mechanical linkage, the tubes rotate together. FIG. 3 clearly shows the change in the radial position of the tubes 12 and 9 as the tubes are rotated.
Also visible in FIG. 3 is slot 8 in the nozzle 7 of reslurrying tube 12. The slot 8 is positioned so that liquid exits the nozzle in the direction indicated by arrow 72. Arrow 72 points in the general direction of the open end 2 of discharge tube 9. It is not necessary to adjust the direction of the liquid with absolute precision. In fact, the apparatus will work as long as the tube 12 points in the general direction of the sludge.
The apparatus operates in the following manner. The sludge discharge tube 9 and the sludge re-slurrying tube 12 begin in the fully retracted position, as indicated by the phantom drawings of FIG. 3. While the tubes 9 and 12 are fully retracted, the centrifuge is operated in its normal mode. That is, process liquid is added to the system through conduit 4, and clean liquid, having left the basket 40 by overflowing the lip 43, is collected by suitable external means.
When the buildup of sludge reaches a predetermined level, valve 23 is closed, shutting off the flow of additional process liquid into the basket 40. At this point, some liquid still remains inside the basket along with the sludge. Valves 25 and 29, which are already in the closed position, remain closed. Valve 27 is already open. Piston 19 is actuated to cause movement of the tubes 12 and 9 from their retracted position. Due to the mechanical linkage between the tubes 12 and 9, and due to the initial positions of the tubes, discharge tube 9 always "leads" re-slurrying tube 12. That is, the end of tube 9 is always located at a greater radial distance, from the center of basket 40, than the end of tube 12. As the tubes are rotated, they gradually move radially outward, within the basket.
The rotation of basket 40 causes liquid to flow into discharge tube 9, through the open valve 27, and back into the centrifuge through re-slurrying tube 12. This liquid then flows out of nozzle 7 as a high-velocity stream, and starts to loosen some of the sludge which has built up along the wall 60 of basket 40. After a short time, some of the sludge becomes a slurry, which can be easily discharged later from the system.
When the re-slurrying described above has proceeded for some time, the system may become ineffective in re-slurrying the remainder of the sludge, because the slurry becomes sufficiently thick to cushion the recirculated material. At this point, valve 27 is closed, and valve 29 is opened allowing the re-slurried material to be discharged from the system, at outlet 31. Then valve 29 is closed again, and valve 25 is briefly opened, allowing process liquid, or any other liquid or solvent, to enter the centrifuge. Valve 25 is then closed, and valve 27 is again opened to permit the re-slurrying process to continue. This reslurrying and slurry-discharging cycle may be repeated as needed, depending on the type and amount of sludge to be removed.
When the sludge removal process is complete, the tubes 12 and 9 return to the fully-retracted position. Valves 25 and 29 are closed, and valves 23 and 27 are then opened to resume normal centrifuging. Valve 27 could also remain closed during the centrifuging process, but it is preferable to leave it open, for reasons of safety.
In the preferred embodiment, the discharge tube 9 and re-slurrying tube 12 do not rotate radially outwardly in one unbroken motion. Instead, at the beginning of the desludging procedure, the tubes are rotated so as to move radially outward for a short, pre-set distance. Then, the tubes are stopped, and the procedure, described above, for discharging the slurry, is executed. Then, the tubes resume their rotation radially outward, and so on. Each radially outward movement results in more slurry being produced from sludge located farther towards the wall of the basket. Each pause in the radially outward movement allows the system to discharge the slurry produced so far, before more re-slurrying is attempted.
The movements of the discharge and re-slurrying tube may be controlled in one of two ways. In the first alternative, the tubes are moved by timer-actuated motors. The rate at which the tubes travel towards the wall of the basket is predetermined, according to the type of sludge in the centrifuge. The harder the sludge, the more time is required for desludging, and the travel speed of the tubes must be slower. Also, a harder sludge requires more frequent ratchetlike motions. The opening and closing of valves 25, 27, and 29 may also be controlled by conventional timers.
An alternative embodiment, which is more automated, is illustrated in FIGS. 4A and 4B. In this embodiment, the sludge discharge tube and sludge re-slurrying tube are rotated by a motor-driven gear arrangement. Gear 91 is mounted to rotate shaft 92, as indicated by arrow 100, the shaft being connected to the discharge tube or the reslurrying tube (not shown in FIG. 4). Gear 91 is rotated by driving gear 93, which is driven by motor 90. Disposed along the gear 91 are several cams 97, 98, and 99. Only three cams are shown, for the sake of clarity, but more cams may be used. Each cam represents a point at which the tubes will stop, so that the slurry in the centrifuge can be discharged. The cams may be spaced at equal intervals, but the spacing may be varied to suit particular types of sludges.
Disposed around gear 91 are three switches, labeled by reference numerals 94, 95, and 96. Switch 96 is disposed to sense the condition wherein the discharge and re-slurrying tubes are in the "home", or fully retracted, position. Switch 95 senses the condition wherein the tubes have reached the end of travel, i.e. the wall of the basket. Switch 94, through arm 101, senses the presence of one of the cams.
FIG. 4A illustrates gear 91 in the "home" position. FIG. 4B illustrates the gear in an intermediate position, the arm 101 of switch 94 being pushed in by cam 98. FIG. 4B also illustrates, in phantom, gear 91 when it has reached the end of travel, and is actuating switch 95.
The means of control for the embodiment of FIG. 4 is illustrated in FIGS. 5 and 6. The system is controlled by microprocessor 105, which receives three inputs. One input, designated by reference numeral 106, is from switch 96, indicating that the gear 91 is in its "home position". The input designated by reference numeral 107 comes from switch 95, and indicates whether the gear 91 has reached the end of its path of travel. The third input, designated "A", signals a condition to the microprocessor which causes the tubes to be stopped during their course of travel, so that the slurry in the centrifuge can be discharged. In the embodiment of FIG. 4, input A represents the presence or absence of a signal from switch 94. In this embodiment, the connection shown from the motor to the input A would not be employed.
Microprocessor 105 has three output lines, connected so as to open and close valves 25, 27, and 29.
FIG. 6 illustrates an example of the programming of the microprocessor. The program begins in block 110, by reading input A, which is described above. In test 111, input A is compared with a reference signal, designated a 0 . In the embodiment of FIG. 4, a 0 could simply be zero, input A being tested to detect whether or not switch 94 has been actuated. If the test is not satisfied (i.e. if switch 94 is not actuated), the program returns to block 110 and reads A again.
Ultimately, the condition in test 111 will be satisfied. Then, the program, in test 112, determines whether the apparatus has reached its end of travel. This test essentially comprises sensing the condition of input 107 (i.e. the output of switch 95). If the end of travel has been reached, the program proceeds to block 113, and causes microprocessor 105 to issue signals to close valve 27, and to open valve 29, thereby causing the remaining slurry to be discharged. The apparatus is then stopped in block 114.
If the end of travel has not been reached, the microprocessor, in block 115, issues a command to stop the motor. Then, in block 116, valve 27 is closed, and valve 29 is opened, allowing the slurry to be discharged. After a short, pre-programmed interval, the microprocessor continues in block 117, wherein valve 29 is closed and valve 25 is opened. Thus, additional liquid is allowed into the basket to replace the liquid lost when the slurry was discharged. After another short time delay, valve 25 is closed, as shown in block 118, and valve 27 is opened, so as to allow the re-slurrying process to continue. In block 119, the microprocessor actuates the motor, and the program returns to block 110.
As stated above, the program illustrated in FIGS. 5 and 6 uses a general input A to determine when to stop the tubes and discharge the slurry. In the embodiment described above, input A comes from the actuation of switch 94 by one of the cams on gear 91. Thus, in this embodiment, the sludge re-slurrying and discharge tubes stop at preprogrammed intervals, without regard to the actual condition of the slurry in the basket.
In another alternative automatic embodiment, the apparatus itself determines when to discharge the slurry, without being pre-set to stop at certain intervals. For example, as indicated schematically by the dotted line in FIG. 5, input A, instead of representing the output of switch 94, can represent the current flowing through motor 90. When the sludge discharge tube encounters resistance due to the wall of hard sludge, the current in the motor increases, as the motor attempts unsuccessfully to maintain the motion of the tubes. The program thus senses when the current rises above a certain level (which level would be a 0 in test 111 of FIG. 6). When the current exceeds that level, the apparatus "knows" that either the tube is abutting a wall of hard sludge, indicating a need for discharging the slurry and introducing more liquid, or the tube has reached the wall of the basket. Therefore, in this embodiment the apparatus stops only when it is actually necessary to stop. Clearly, the number of stops required will vary with different types of sludge.
In still another embodiment, illustrated schematically in FIG. 7, the need for discharge of the slurry is sensed by measuring a differential pressure. FIG. 7 illustrates a portion of pipes 5 and 6 of FIG. 1. The pipes are provided with pressure sensors 120 and 121, and differential pressure sensor 122 measures the pressure difference between sensors 120 and 121. The output of sensor 122 becomes the input A of FIGS. 5 and 6. When the slurry has become relatively viscous, indicating the need for discharge, the pressure drop between pipes 5 and 6 increases, as pipe 6 tends to become more and more clogged. When the pressure drop exceeds a pre-set limit (which would be a 0 in test 111 of FIG. 6), the apparatus automatically stops the tubes and discharges the slurry.
It is clear that FIGS. 5 and 6 can represent at least three automated embodiments of the invention. Input A can be the signal from switch 94 which is actuated by the cams on gear 91. Input A can instead be a signal indicating that the current in motor 90 has exceeded a pre-set level. Input A can also be a signal indicating that the pressure drop between the re-slurrying tube and discharge tube has exceeded a pre-set level. Other parameters can be chosen for input A, within the scope of the invention.
The embodiment of FIG. 7 has the advantage of automatically discharging slurry from the basket, when the slurry becomes viscous. In the automatic embodiment wherein the motor current is monitored, there is likely to be more wear on the discharge tube, because slurry discharge is not initiated until the discharge tube has pushed into the wall of hard sludge.
There are various other modifications possible to the above-described embodiments. Varying speeds of travel could be employed, and these speeds could be programmed into the microprocessor. Also, the sludge discharge tube and the sludge re-slurrying tube can be rotated independently, using separate motors, instead of using the linkage shown herein.
It is also understood that the microprocessor could be replaced with mechanical means for accomplishing the same object. Still another alternative is to use, instead of a microprocessor, a combination of solid state switches and timers. Such a combination would have the advantage of requiring fewer moving parts (or none at all), as compared with a purely mechanical or electro-mechanical arrangement, although it might not have the flexibility of an actual microprocessor. Any of these embodiments may be used, as long as the embodiment chosen implements the logic which is illustrated in FIG. 6 and described above. It is believed that, in most cases, a microprocessor is a convenient means for implementing the invention.
It is also noted that other means for detecting resistance to movement of the discharge tube can be used. Instead of measuring the current in the motor, one could directly monitor the speed of rotation of the tubes, and could sense when that speed has fallen sharply. Knowledge of the speed of rotation of the tubes, coupled with knowledge of the absolute position of the tubes, is sufficient to control the apparatus in the automatic manner contemplated by FIGS. 5 and 6.
Other modifications can be made to the invention. The size, shape, and direction of the nozzle may be changed. The particular internal structure of the centrifuge basket may be varied. The means of rotating the tubes and controlling the valves may be changed. The automated embodiment, while described with reference to a motor and gear arrangement, could be powered by hydraulic or pneumatic drive mechanisms. As noted earlier, the apparatus may be controlled electronically by a microprocessor, or by purely mechanical means. These and other modifications are to be deemed within the spirit and scope of the following claims. | An improved desludging device for basket centrifuges facilitates the automatic withdrawal of hard sludge from the centrifuge. The device includes a sludge discharge tube and a sludge re-slurrying tube, the tubes being connected in a loop, so that fluid exiting the centrifuge through the discharge tube reenters the centrifuge through the re-slurrying tube. The re-slurrying tube terminates in one or more nozzles or slots, pointed in the general direction of the discharge tube. This continual recirculation of fluid causes the hard sludge in the centrifuge to return to the form of a slurry, and the slurry is periodically withdrawn from the centrifuge. The re-slurrying effect may be enhanced by the occasional introduction of some process liquid, or other liquid, into the centrifuge. The sludge discharge tube and re-slurrying tube are mechanically linked, and are programmed to move towards the rim of the centrifuge until substantially all the sludge is removed. In alternative embodiments, the apparatus automatically starts and stops the re-slurrying and discharge cycle. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to the art of safety belts, and more particularly to an improved safety belt particularly adapted for use as a lap or shoulder restraining belt in motor vehicles.
The use of such automobile seat and shoulder belts though generally recognized as minimizing injury in vehicle collisions is resisted by many drivers because of the discomfort encountered in the use of these belts. Among the primary causes of discomfort is the fact that the wearer is restricted in movement not only during a collision, but also during normal driving.
BRIEF DESCRIPTION OF INVENTION
It is with the above considerations in mind that the present improved safety belt has been evolved, providing a desired degree of freedom of movement to the wearer during normal driving but snagging to a locked position in the event of a sharp change of speed or direction.
It is accordingly among the primary objects of the invention to provide a safety belt which will permit the wearer to move about to the extent normally desired during normal driving, but which snags to a locked position when the vehicle is subjected to rapid changes of speed or direction, such as occurs during a collision.
According to the invention, this and other objects which will appear hereafter are attained by training a belt around a spring biased rotatable drum with the spring biasing the drum to wind the belt thereabout. A ratchet wheel is secured to one end of the drum and a pawl is positioned to engage the ratchet teeth preventing rotation of the drum upon a rapid change of direction or speed of an automobile or the like in which the belt is employed. The pawl is moved to a ratchet engaging position by a pendulum coupled to the pawl, with a change in inertia of the pendulum moving the pawl.
A feature of the invention resides in the mounting of the pawl on a displaceable axis of rotation permitting pawl displacement during ratchet engagement to assure desired seating of the pawl with respect to the ratchet teeth.
Another feature of the invention resides in the provision of a cam surface on the pawl implementing return of the pendulum to a centered position.
BRIEF DESCRIPTION OF THE DRAWINGS
The specific details of the invention will be described in full, clear, concise and exact terms in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side elevational view of a belt holder with the pendulum and fulcrum seat shown in partial cross-section;
FIG. 2 is a view of the interior of the belt holder shown in FIG. 1, with parts broken away showing the drum, ratchet teeth, and pawl;
FIG. 3 is an end view at right angles to the FIG. 2 view with the pendulum and pivot arm rotated 90°;
FIG. 4 is a detail elevational view of the pawl and ratchet in locked position;
FIG. 5 is a detail elevational view of the pawl and ratchet in an undesired point to point position;
FIG. 6 is a detail view looking up at the lower right hand corner of the holder as viewed in FIG. 3 showing a plan view of the lever connection between pendulum and pawl;
FIG. 7 is a detail elevational view of the lever seen in FIG. 6 in a position moving the pawl to a ratchet engaging position;
FIG. 8 is a detail elevational view of the upper end of the pendulum fulcrum when the pendulum is pivoted;
FIG. 9 is a detail elevational view of a modified pawl shown in an inactive position with respect to the ratchet teeth;
FIG. 10 is a detail elevational view of the modified pawl of FIG. 9 in ratchet tooth engaging position; and
FIG. 11 is a detail view at right angles to the views of FIG. 9.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now more particularly to the drawings, like numerals in the various FIGS. will be employed to designate like parts.
As best seen in FIGS. 1-3, the safety belt construction embodying the invention is formed with a belt holder housing 1 in which a hollow drum 2, as best seen in FIGS. 2 and 3 is mounted on a rotatable shaft 3 rotatably supported between the side walls of the housing 1 as best seen in FIG. 3. A pin 4 secures drum 2 to shaft 3 for rotation therewith.
The hollow drum 2 is formed with a slot 5, and the belt 6 has one end secured with respect to the drum 2 by inserting a belt end into the drum 2 through slot 5. The inserted belt end is looped and shaft 3 inserted through the loop and drum. The belt end, drum and shaft are locked together by means of pin 4, as best seen in FIG. 2. As a result of this arrangement the belt may be replaced when worn.
Ratchet teeth are associated with the drum to permit control of drum movement. In accordance with the invention, a ratchet wheel 8, as best seen in FIGS. 2 and 3, is fixed to the drum 2. As will be apparent, the ratchet wheel 8 may either be fixed to the shaft or formed integrally with the drum. A pawl 9, as best seen in FIG. 2 is pivoted on shaft 10 in housing 1 adjacent the teeth of ratchet wheel 8.
A drum biasing torsion coil spring 11, as best seen in FIG. 3 is mounted in spring housing 12 at one end of housing 1. The outer end of spring 11 is anchored to spring housing 12 and the inner end of spring 11 is secured to drum shaft 3. The spring 11 is tensioned to resist the unwinding of the belt from the drum.
A pendulum 13 is mounted on a pivot arm 14, as best seen in FIG. 3. As illustrated pivot arm 14, is secured at its lower end to the center of the top of cylindrical pendulum 13, and is curved and formed at its other end with a point adapted to sit in fulcrum seat 15 formed on an extension from housing 1. The pivot point end of arm 14 is formed with a spring engaging recess opposed to the fulcrum point in which one end of spring 16 rests. The other end of spring 16 is engaged in casing projection 17, as best seen in FIG. 3, so that the spring 16 can act to bias the fulcrum point into fulcrum seat 15.
The lower end of pendulum 13, as seen in FIG. 3, is formed with a recess receiving a trunnion 19. Trunnion 19 is secured to one arm of a class 2 lever 20 pivoted at 21 on a U-shaped housing projection 22, as best seen in FIGS. 3 and 6. The other arm 23 of lever 20 is positioned beneath pawl 9 as viewed in FIGS. 2 and 4, so that when trunnion 19 is moved downwardly as viewed in FIGS. 3 and 7; lever arm 23 will move upwardly against pawl 9 to bring pawl 9 against ratchet teeth 8, as seen in FIG. 4. A biasing spring 24, as seen in FIGS. 3, 6 and 7, is arranged between the base of U-shaped projection 22 and trunnion 19.
To insure desired engagement of the pawl 9 with respect to the ratchet teeth 8, proper positioning being shown in FIG. 4, and to prevent an undesired point to point engagement, as shown in FIG. 5, which may result in pawl or ratchet teeth breakage, the pawl 9 is formed with an oval bearing hole 25, as shown in FIG. 2. A compression spring 26 is arranged between the pawl shaft 10 and the pawl 9 with the spring 26 tending to bias the pawl to the FIG. 2 position but permitting pawl movement axially with respect to shaft 10. Additionally, the pawl 9 is formed with a cam arm 27 engaging fixed cam surface 28 on the housing, so that upon engagement of the pawl with the ratchet teeth, the rotation of drum 2 will move pawl 9 to engage cam surface 28, as seen in FIG. 5, causing the pawl to be positively displaced into desired seating engagement with ratchet teeth 8, as shown in FIG. 4.
A modified pawl arrangement is shown in FIGS. 9-11 for implementing return of the pendulum to a central position. The modified pawl 9' is formed with a cam arm 31 engaged by lever arm 23. Bearing hole 25' is formed of an oval configuration, as seen in FIG. 9, with its axis extending obliquely. Thus, upon engagement of pawl 9', with ratchet teeth 8, the ratchet teeth will urge the pawl to move against the biasing action of pawl spring 26' to the position shown in FIG. 7, with pawl shaft 10 at the lower end of bearing hole 9. As a result of this pawl shift on shaft 10, cam arm 31 will ride against lever arm 23, urging it downwardly so that lever 20 will assume the position shown in FIG. 11 with the trunnion 19 centering pendulum 13.
OPERATION
In use, the belt assembly is formed as above described and where used in a vehicle, mounted to permit the belt to be trained either over the lap or shoulders of the wearer. The housing 1 may thus be positioned adjacent the seat or seat back. The free end of the belt is drawn out of the housing over the lap or shoulders of the user and anchored in conventional fashion.
During normal driving, pendulum 13 is centered as viewed in FIGS. 1 and 2, and pawl 9 is free of engagement with ratchet wheel 8, as viewed in FIGS. 2 and 9.
However, where there is a rapid change of inertia due to a rapid change of vehicle speed or direction, the pendulum, which is selected with a moment of inertia responsive only to the changes of speed or direction, regarded as critical, will be displaced from its central position swinging about the fulcrum provided by fulcrum seat 15, moving trunnion 19 downwardly as viewed in FIG. 7, to cause the lever arm 23 to move up against pawls 9 or 9' against the ratchet teeth 8.
Spring 16 bearing against pendulum pivot arm 14 as best seen in FIGS. 1 and 8, has its center line shifted as a result of the pendulum movement and the spring provides an accelerating force urging the pendulum to swing in its direction of movement, and provide a biasing force tending to maintain the pendulum in its displaced position.
Similarly, spring 4, as best seen in FIGS. 3 and 7, has its center line shifted by the displacement of trunnion 19 and lever 20, accelerating the upward movement of lever arm 23 against the pawl.
Springs 16 and 24 thus provide a locking action, on one hand biasing the pendulum to a centered position, and when displaced from this centered position, biasing the pendulum to an off-center position. By selecting appropriate spring constants, the sensitivity of the locking action can be controlled.
When the vehicle speed or direction has become relatively constant, the pendulum returns to its centered position. The pawl 9 will be released from ratchet teeth 8 by the release of tension on belt 6 which permits drum 2 to be turned by drum biasing return spring 11, causing pawl 9 to be moved down by ratchet teeth 8. The downward movement of pawl 9 moves lever arm 23 down, raising trunnion 19 into pendulum recess 18, which is preferably conical so that the trunnion will center on the cone apex centering the pendulum 13. Springs 16 and 24 are simultaneously returned to their starting positions.
In the FIGS. 9-11 embodiments of the pawl, the pendulum is returned to its center line position simultaneously with the engagement of the pawl with the ratchet teeth, without requiring release of tension on the belt. As above described, the tension on the belt forces teeth 8 against pawl 9', shifting its position with respect to pawl shaft 10. The obliquely arranged bearing hole 25' permits the pawl to move with the ratchet a slight distance, simultaneously causing cam arm 31 to ride against lever arm 23 camming the lever arm down to raise trunnion 19 into seating position in recess 18 to center the pendulum.
The above disclosure has been given by way of illustration and elucidation, and not by way of limitation, and it is desired to protect all embodiments of the herein disclosed inventive concept within the scope of the appended claims. | A safety belt construction adapted for use as an automobile seat or shoulder belt providing normally desired freedom of movement to a wearer during normal driving with the belt snagged into a locked passenger retaining position upon a rapid change of speed or direction of the vehicle. A belt is wound on a spring biased rotatable drum, the spring tending to rotate the drum to wind the belt thereon. At relatively constant speed and direction, the belt may readily be unwound from the drum. However, upon a rapid change of direction or speed, ratchet teeth associated with the drum are engaged by a pawl preventing drum rotation and holding the belt tightly. The pawl is actuated to a drum locking position by a pendulum moving in response to rapid speed and direction changes. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to nonlinear optical systems, and particularly to a new class of organic complexes capable of second harmonic generation.
The high light intensities available in coherent laser radiation have led to the development of nonlinear optical systems. The optical properties of materials are different at high intensities, since the electronic oscillators are driven so hard that anharmonic properties become evident. One such effect is harmonic generation of light, for example, conversion of red laser light to ultraviolet radiation of exactly doubled frequency. This effect known as second harmonic generation was first observed when quartz crystals were illuminated by laser radiation. Since this discovery, a number of inorganic and organic materials capable of second harmonic generation (SHG) have been discovered. A useful review of the state of the art relating to nonlinear properties of organic materials is provided by Williams, ed., Nonlinear Optical Properties of Organic and Polymeric Materials, (American Chemical Society 1983).
The nonlinear optical properties of organic and polymeric materials are currently under intensive study. Major research efforts are now directed towards searching for new molecules possessing large nonlinear polarizabilities and controlling molecular orientation on a microscopic level to influence bulk nonlinear optical properties. Over the past few years, research has indicated that organic molecules having conjugated pi electron systems or low-lying charge transfer excited states often possess extremely large second order polarizabilities. However, the potential of such molecules often cannot be utilized because of unfavorable alignment in the crystalline phase. In the case of SHG, second order susceptibility vanishes for centrosymmetric crystals.
A number of approaches have been taken to circumvent this problem. Use of a chiral molecule ensures formation of a noncentrosymmetric crystal and mathematically guarantees a nonvanishing second order susceptibility, but not necessarily a large one.
It has now been found that guest-host inclusion complexation can be used to control bulk nonlinear optical properties. Specifically, second harmonic generation by optically nonlinear aniline and aminopyridine compounds can be greatly enhanced by inclusion complexation with selected cyclodextrin compounds.
SUMMARY OF THE INVENTION
The present invention provides a nonlinear optical element capable of second harmonic generation, comprising an inclusion complex of a host compound selected from the group consisting of cyclodextrin compounds and substituted derivatives of cyclodextrin compounds, and a guest compound selected from the group consisting of anilines, pyridines, pyrimidines, quinolines, and naphthalenes. The present invention also provides methods of generating second harmonic radiation, comprising illuminating a nonlinear optical element as defined above with a source of coherent optical radiation.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE corresponds to the optical arrangement used to irradiate samples prepared for evaluation in the Examples.
DETAILED DESCRIPTION OF THE INVENTION
The nonlinear optical elements of the present invention comprise guest-host inclusion complexes of cyclodextrin compounds and certain optically nonlinear anilines, pyridines, pyrimidines, quinolines, and naphthalenes. Suitable guest molecules for complexation with a selected host are selected on the basis of knowledge of their molecular dimensions with respect to the cavity dimensions provided by a particular cyclodextrin host. Bender et al., Cyclodextrin Chemistry (Springer-Verlag, New York, 1978), pp 1-27, describe physical properties of cyclodextrins and inclusion complexes formed with cyclodextrins. This disclosure is hereby incorporated by reference. Bender et al. disclose that the known cyclodextrins exhibit the following internal cavity diameters:
______________________________________cyclodextrin 4.5 Åβ-cyclodextrin 7.0 Åγ-cyclodextrin 8.5 Å______________________________________
Accordingly, suitable guest molecules must be accommodated within a selected cyclodextrin host in a manner which results in the enhancement of nonlinear optical properties.
Useful cyclodextrin molecules for preparing the nonlinear optical elements of the present invention are α-, β-, and γ-cyclodextrin and certain substituted derivatives thereof. Preferred host compounds are β-cyclodextrin and substituted derivatives of β-cyclodextrin.
Useful guest molecules for preparing inclusion complexes with the foregoing host molecules are anilines pyridines, pyrimidines, quinolines, and naphthalenes meeting the molecular size criterion specified above. In addition to this criterion a suitable guest molecule must possess a large molecular second order polarizability, that is, the molecule must exhibit a large dipole moment change from the ground state to the excited state, or low-lying charge transfer excited states. Spectroscopic measurements can be employed to determine in each case whether effective guest-host complexation occurs.
Preferred guest compounds are substituted amines of the formula ##STR1## wherein
A is C or N;
R 1 is --NH 2 , --NHCH 3 , or --N(CH 3 ) 2 ;
R 2 is --NO 2 or --CN; and
Y is --H, --CH 3 , --OCH 3 , --OH, --F, or --Cl.
More preferred quest compounds are amines of the foregoing formula wherein Y is --H. Particularly preferred guest compounds are those wherein A is C.
For example, para-nitroaniline is a well-known optically nonlinear molecule having a large second order polarizability, but its macroscopic second order susceptibility vanishes in the centrosymmetric crystal habit. Formation of a 1:1 inclusion complex with β-cyclodextrin provides a powder with an SHG efficiency 2-4 times that exhibited by urea, a common organic reference material for SHG.
Generally, the molecular interaction by which guest-host complexation is obtained should exhibit directional selectivity for both guest and host to minimize orientational cancellation of bulk second order optical properties.
The preferred substituted amine derivatives described above exhibit a significant second order polarizability but a low bulk second order susceptibility. This group includes amines which exhibit charge transfer between donor and acceptor substituent groups. Exemplary are p-nitroaniline p-dimethylaminobenzonitrile, N-methyl-p-nitroaniline and N,N-dimethyl-p-nitroaniline, and 2-amino-5-nitropyridine. Preferred host molecules for formation of complexes with these amine derivatives are β-cyclodextrin and such substituted variants of β-cyclodextrin as dimethyl β-cyclodextrin.
Processes for producing the inclusion complexes employed in the present invention comprise mixing an aqueous solution of a selected host molecule with a preselected molar amount of a suitable guest molecule dissolved in an appropriate solvent, and allowing the resulting inclusion complex to precipitate as crystals from the reaction mixture. Suitable solvents of nitroaniline guest molecules include water and such organic solvents as diethyl ether, dimethylformamide, and dimethylsulfoxide. Of the foregoing water is preferred. Generally, solution temperatures ranging from 20° C to 100° C can be employed preferably 20° C to 30° C. To effect crystallization of the complex, the resulting solution can be cooled to a lower temperature, for example 0° C to 5° C.
The following examples illustrate selected aspects of the present invention. In the Examples, all parts and percentages are by weight unless otherwise indicated and all degrees are Celsius (°C).
Experimental Procedure
Samples prepared for evaluation in the following examples were irradiated by a Nd-YAG laser, using an optical arrangement corresponding to that depicted in the FIGURE. As indicated in the FIGURE, filter 2 was employed to adjust the intensity of the monochromatic signal provided by Nd-YAG laser 1. The resulting beam was directed through a cental hole 3 in parabolic mirror 4, illuminating a powder sample 5. Light emerging from sample 5 was collected by mirror 4, and transmitted to a beam splitter 6, which divided the signal into two parts. One part was passed through a narrow band filter 7, having a full-width half maxima of 10 nm, centered at a second harmonic wavelength to be detected. The signal passing through filter 7 was detected by photomultiplier 8. The other beam provided by beam splitter 6 was directed through a broad band filter 9, having a full-width half maxima of 70 nm and detected by a second photomultiplier 10. Thus, in each experiment two channel detection enabled discrimination against potential spurious signals from the sample.
In each experiment, polycrystalline urea powder having an average particle size of 90 to 125 μm was used as a reference material. The intensity of the second harmonic radiation generated by each sample tested was thus measured relative to that provided by urea.
EXAMPLE 1
A mixture of near-saturated aqueous solutions of β-cyclodextrin and p-nitroaniline was stirred overnight. The resulting precipitated complex was collected and dried in air, then tested for second harmonic generation. The measured SHG efficiency was about 70% of that provided by urea.
Control experiments indicated that neither β-cyclodextrin nor p-nitroaniline alone were active.
The experiment was repeated except that β-cyclodextrin was replaced with α-cyclodextrin and γ-cyclodextrin, respectively. Neither of these compounds provided complexes with p-nitroaniline which were SHG active.
EXAMPLES 2-15
In Examples 2-15, which are summarized in Table I, below, the experiment described in Example 1 was substantially repeated, using complexes prepared using varying molar ratios of p-nitroaniline (p-NA) and β-cyclodextrin (β-CD). In each experiment, solutions of p-NA and β-CD were gently heated to facilitate dissolution, and the resulting solutions were cooled slowly to precipitate crystalline complexes. In some experiments crystalline complexes were dried by heating in an oven at 60° to 70° for several days. In the experiments described below as Examples 6 and 7, samples prepared and tested as Examples 3 and 5 were dried at 60° to 70° for an additional 2 weeks and then held at about 23° for 3 weeks prior to testing.
TABLE I______________________________________Examples 2-15: Second Harmonic Generationby Various Samples of p-Nitroaniline/β-CyclodextrinCrystalline Inclusion Complexes Molar Ratio: Complex Drying SHG Relative toExample β-CD/p-NA Conditions Urea______________________________________2 0.5 Air 0.53 0.5 Oven 1.04 1.0 Air 2.45 1.0 Oven 4.26 1.0 Oven 0.67 0.5 Oven 2.08 1.82 Air 0.29 0.69 Air 2.210 3.70 Air 0.011 1.0 Air 3.512 0.69 Air 2.213 0.5 Alr 0.7714 0.33 Air 2.215 0.25 Air 1.0______________________________________
EXAMPLE 16
In this experiment the procedure employed in Example 2above, was substantially repeated except that p-nitroaniline was replaced with p-N,N-dimethylaminobenzonitrile (DMABN) to provide a molar ratio of β-cyclodextrin to DMABN of 1.0. The resulting complex was dried in air, and then tested for second harmonic generation. The SHG signal measured was approximately 1.56 per cent of that provided by a urea control.
EXAMPLES 17-22
In this series of experiments, 2.0 g (1.8 mmol) β-cyclodextrin were dissolved in 100 mL distilled water, and the resulting solution filtered though a medium glass frit. Meanwhile, a p-nitroaniline derivative to be employed as a guest molecule was dissolved in a minimum quantity of diethyl ether (typically 30-75 mL) and the resulting solution filtered. The foregoing two filtrates were then combined, and the resulting mixture stirred overnight in an open flask. Any resulting solids were then separated by filtration to provide a first crop (Crop 1), and the filtrate was then held at 5° for about 24 hours. Any additional precipitate (Crop 2) was then separated by filtration. In this manner, guest-host complexes of β-cyclodextrin and N-methyl-p-nitroaniline (p-NMeA), N,N-dimethyl-p-nitroaniline (p-NDMeA). and p-nitroaniline (p-NA) were obtained. Each complex was then tested for SHG by procedures substantially similar to those previously described. The results obtained are set forth in Table II, below.
The melting points of the complexes obtained are also set forth in Table II. All complexes melted with decomposition. In Example 20, five crops of product complexes were obtained. The first crop exhibited a very low melting point and was discarded. The sample designated "Crop 1" in Table II was prepared by combining the second and third crops, and the sample designated "Crop 2" in Table II was prepared by combining the fourth and fifth crops obtained. As a control in these experiments. N-dimethyl-p-nitroaniline was evaluated by itself, rather than as a complex with β-cyclodextrin. This control experiment is designated by the letter "A" in Table II, below.
TABLE II______________________________________Second Harmonic Generation byGuest-Host Complexes of β-Cyclodextrin andSelected Derivatives of p-Nitroaniline Melting SHG Yield (g) Point RelativeExample Guest Crop 1 Crop 2 (°C.) to Urea______________________________________17 P-NMeA 0.15 0.45 277-285 1.018 p-NDMeA 1.80 -- 278-282 0.019 p-NA 0.13 0.55 288-289 1.020 p-NMeA 0.25 0.61 285-288 0.2521 p-NDMeA 1.99 -- 274-285 0.1022 p-NDMeA -- -- -- 0.13A -- -- -- -- 0.5______________________________________
EXAMPLE 23:
Characterization of p-Nitroaniline-β-Cyclodextrin Guest-host Complex
A. Equilibrium Constant
The absorption spectra of p-nitroaniline in the presence of varYing amounts of β-cyclodextrin in aqueous solution show an isosbestic point, indicating complex formation. The formation constant of the complex was determined to be 160 M -1 . B. Circular Dichroism
The absorption spectrum of p-nitroaniline in aqueous solution shows induced-circular dichroism upon addition of β-cyclodextrin and α-cyclodextrin (positive Cotton effect). This indicates that the long molecular axis of p-nitroaniline is aligned with the cavity axis of β-cyclodextrin and α-cyclodextrin.
C. NMR
Proton NMR spectra obtained for complexes of β-cyclodextrin and p-nitroaniline indicate that interior protons, H-3 and H-5, of β-cyclodextrin move upfield upon addition of p-nitroaniline, while exterior protons H-1, H-2, and H-4 remain relatively unchanged. This indicates that p-nitroaniline is included within the B-cyclodextrin cavity, rather than associated with the periphery of the cyclodextrin structure. The protons meta to the amino group of p-nitroaniline move upfield by about 0.06 ppm upon complexation, while the ortho protons remain relatively unchanged. This suggests that p-nitroaniline enters the β-cyclodextrin cavity preferentially from the nitro side.
D. X-Ray Diffraction
The powder x-ray diffraction patterns obtained for β-cyclodextrin, p-nitroaniline, and complexes of β-cyclodextrin and p-nitroaniline are different. These results suggest that the guest-host complexes can be visualized as an oriented inclusion compound of the aniline derivative and the toroidal cyclodextrin. The cyclodextrin is nonsymmetric about the axis normal to its toroidal axis, and insertion of the aniline derivative occurs with a preferential orientation relative to this asymmetry. Because cyclodextrin itself is chiral, its crystals and those of cyclodextrin complexes will be non-centrosymmetric, and thus exhibit anisotropy along at least one crystal axis. The non-random dipole orientation within the chiral cavity will then result in a bulk dipolar anisotropy in crystals of the complex, which is a necessary precondition for second harmonic generation.
Example 24
A 1:1 molar mixture of β-cyclodextrin and 2-amino-5-nitropyridine was prepared in water and gently heated to facilitate dissolution. The resulting solution was cooled slowly to precipitate a crystalline complex. After drying in air, the complex exhibited an SHG efficiency of 7% of that shown by urea. | Inclusion complexes of cyclodextrin compounds and suitable guest molecules are capable of second harmonic generation when illuminated by coherent optical radiation. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of application Ser. No. 221,585, filed Dec. 31, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a pressure control device for a pressure accumulator, in particular, for automotive vehicles with a brake slip control system. The pressure accumulator is fed by a disconnectible pump and at least two user components are adapted to be connected to the pressure accumulator, the user components requiring different minimum feed pressures for correct operation.
The problems with such a feeding of different pressure fluid user components are that the admissible lowest accumulator pressure has to be determined according to the highest minimum feed pressure of all connectible user components. Consequently, the pump feed will be constructed such that the pressure in the pressure accumulator is not allowed to drop under the level of the highest minimum pressure required. As a result, the pump feed has to be switched on relatively often, although the user component with the highest minimum feed pressure is put into operation only rarely.
Pressure control systems of the aforementioned type are described in the book by Dr.-Ing. Erwin Samal "Outlines of Practical Control Technology", published by R. Oldenbourg, 1967. On page 135, a pressure control valve is shown switching on and off the pump feed dependent on the pressure prevailing in a pressure accumulator. As another example, a water level regulator is shown on page 137 controlling the height of a water level by using an electric switching arrangement such that the pump feed is switched on upon attainment of a presettable minimum amount and the water level increases up to a presettable maximum amount, upon attainment of which the pump feed is switched off.
Likewise, pressure switches are shown in the handbook "Vickers Handbook of Hydraulics", 1966, in which a hydraulic fluid acts on a piston movable against the force of a spring and actuating a microswitch after having travelled a predetermined distance. However, pressure switches of this kind are only able to be used for switching on or off a unit so that such a switch would have to be available in duplicate, if a greater hysteresis were desired. Hydraulic switches with adjustable minimum switching pressure and adjustable maximum switching pressure have been described on pages 96 and 97.
The prior art switching elements mentioned hereinabove are not in all cases in a position to satisfactorily solve the problem of pressure control. Particularly in the event of several, different user components being connected to one single pressure accumulator, it is desirable to control the pressure in the pressure accumulator such that in each case only the minimum feed pressures of the connector user components are guaranteed. Especially with regard to brake slip control systems, pressure fluid being pressurized as constantly as possible is required for governing the pressure modulation. At the same time, however, the pressure accumulator feeds a hydraulic auxiliary force for actuation of the brake unit and maybe still other hydraulic user components. As to the hydraulic brake booster, the controlled delivery of pressure is not subjected to such strict conditions of maintaining constrant values as is required in the case of pressure fluid serving for control of the pressure modulation for the brake slip control system.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a device for pressure control of the type referred to hereinabove, rendering possible the distribution of the required pressure fluid for several user components with different minimum feed pressures by means of a common pressure accumulator and decreasing the energy necessary for distribution of the accumulator pressure. In addition to this, the device is safe in its mode of operation and simple in its construction.
A feature of the present invention is the provision of a pressure control device for a pressure accumulator for automotive vehicles having an antiskid control system comprising: at least one user component in addition to the antiskid control system capable of being coupled to the accumulator, the one user component and the antiskid control system requiring different minimum feed pressures for correct operation; a controllable pump arrangement to feed pressure fluid to the accumulator; and a switching device coupled to the accumulator to switch on a pump drive means connected to the pump arrangement when pressure in the accumulator falls below a bottom switching threshold corresponding to a first minimum feed pressure for the one user component, to switch off the pump drive when pressure in the accumulator attains a top switching threshold corresponding to a second minimum feed pressure for the antiskid control system, the second minimum pressure being greater than the first minimum pressure and to increase the bottom switching threshold to approximately the top switching threshold when the antiskid control system is operated.
This device in accordance with the present invention may be constructed such, for example, that a pressure sensor monitors the accumulator pressure and transmits an electric signal to an electronic control device governing the pump drive as a function of electronically established switching thresholds, with at least the bottom switching threshold being modified dependent upon the switched-on user components.
According to a preferred embodiment of the device, the switching device includes a first pressure sensor, acted upon by the accumulator pressure, a second pressure sensor, acted upon by the pressure of a return line of a user component, and an electric switch controlled by the first and second pressure sensors. This way, two different pressures are monitored by one switching device, and the switch may be actuated corresponding to the pressure conditions.
The first pressure sensor includes a first piston acting on the electric switch against the force of a spring via a second piston and the second pressure sensor includes a third or pressure piston connected to the second piston via a lever arrangement. The lever arrangement includes a swivelling lever having one end portion engaging a radial opening of the second piston and the other end portion connected to an actuating member which is connected to the third piston.
It is suitable for determination of the hysteresis of the switching device, i.e. the maximum distance between the switching thresholds, that the first piston and the second piston are interconnected by a lost motion clutch, and that a friction member exists which acts on the second piston. A particularly simple arrangement of the friction member is achieved in that the friction member is located in an opening of the switching device's housing and is pressed radially against the circumferential surface of the second piston by means of a spring.
To the end that the pump drive is not switched on in the event of sufficient pressure prevailing in the pressure accumulator and the third piston of the second pressure sensor is simultaneously pressurized and that the chamber bounded by the third piston takes care of an accumulating function from time to time, the actuating member is connected to the third piston such that the third piston acts on the actuating member via a spring when moving in the sense of the switching-on of the switch and acts on the actuating member directly when moving reversely. To this end, the force of the spring is greater than the friction contact between the friction member and the second piston.
To avoid jamming of the lever arrangement the one end portion of the swivelling lever has a ball on the end thereof located in the radial opening of the second piston with clearance and the actuating member includes a pivot engaging an oval opening in the other end portion of the swivelling lever.
BRIEF DESCRIPTION OF THE DRAWING
The above-mentioned and other features and objects of the present invention and the manner of obtaining them will become more apparent by reference to the following description taken in conjunction with the drawing, the single FIGURE of which is a longitudinal cross-sectional view of a pressure control device in accordance with the principles of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the FIGURE, the pressure control device includes a housing 1 of a hydraulic-electrical switching device 2 which actuates in response to the pressure in the pressure accumulator 3 and the prevailing pressure of return line 4 a microswitch 5, which electrically operates a relay 8 via the electric control lines 6 and 7.
When relay 8 is activated and closes contact 9, voltage will be applied via the line 13 to the electric motor 10, motor 10 having a ground connection 14. Electric motor 10 when put into operation will drive the pumps 11 and 12 through a common drive, with pump 11 delivering pressure fluid from the suction connection 15 of the pressure fluid reservoir 16 via a hydraulic switching member 17 to pressure accumulator 3. Provided in the pressure line 18 is a check valve 19 opening against the pressure of pressure accumulator 3 and, thus, preventing depletion of pressure accumulator 3 in the event of leakage of pump 11.
To filter out any dirt particles possibly existing in pressure fluid, a filter 20 is provided in suction connection 15.
The pressurized fluid of pressure accumulator 3 is led via a pressure line 21 to a pressure chamber 22 of hydraulic-electrical device 2. As a branch of pressure line 21, another pressure line 23 leads to the user components HV and AS. User component HV, for example, may be a hydraulic brake force boosting circuit, such as a pressure differential brake booster. User component AS, for example, may be a known antiskid control system such as disclosed in U.S. Pat. No. 4,305,624 including a normally open solenoid controlled inlet valve coupled to at least one wheel brake circuit to supply brake fluid thereto from the master cylinder upon brake pedal actuation, a normally closed solenoid controlled outlet valve coupled between the one brake circuit and a return line, such as return line 4, and a control unit to close the inlet valve to block brake fluid flow into the wheel brake circuit and to open the outlet valve to release pressurized brake fluid from the wheel brake circuit when an impending skid condition is detected, resulting effectively in a modulation of the braking action at the brake of the wheel brake circuit.
A first piston 24 is located in pressure chamber 22 sealingly penetrating an end wall 25 of pressure chamber 22 with its portion 26, the diameter of which is dimensioned smaller than the portion in chamber 22. Located between end wall 25 and the portion 27 of first piston 24, whose diameter is dimensioned the largest, is a spring 28, the force of which has to be overcome by first piston 24 when moving in the direction of end wall 25.
The smaller portion 26 of first piston 24 enters into a chamber 29 and ends in chamber 29 in a head 30 constructed with a greater diameter than portions 26 and 27 of first piston 24. Arranged in chamber 29 is a second piston 31 whose end surface 32 abuts without clearance a contact pin 33 of a microswitch 5 fixedly secured in housing 1.
On the side remote from end surface 32, second piston 32 embraces head 30 so that first piston 24 and second piston 31 abut each other in the illustrated rest position. Head 30, and, consequently, first piston 24, is movable relative to second piston 31 by an axial clearance x. This connection of first piston 24 with second piston 31 is a lost motion clutch and effects a certain hysteresis of the monitoring switching device, as will be described hereinbelow. Second piston 31 is axially movable within limits between the stops 34 and 35 and is loaded by a friction member 36 acting radially thereon. Friction member 36 is urged radially into abutment with piston 31 with a predetermined force by means of a spring 37 which is disposed in a bore 38 located radially with respect to second piston 31.
The mode of operation of the parts of the hydraulic-electrical switching device 2 described to this point is as follows.
In the rest position illustrated, second piston 31 bears against stop 35, and microswitch 5 is closed. Relay 8 is activated and contact 9 is thus closed, thereby delivering voltage to motor 10. Pump 11 delivers pressure fluid from pressure fluid reservoir 16 to pressure accumulator 3. The pressure prevailing in pressure accumulator 3 is transmitted to chamber 22 via pressure line 21. The pressure in chamber 22 acts on first piston 24 and displaces first piston 24 against the force of spring 28 in the direction of microswitch 5. After the axial clearance x is overcome, second piston 31 will be entrained by first piston 24 and moved towards microswitch 5. Contact pin 33 opens the previously closed contact of microswitch 5. Relay 8 is de-activated due to the break of the relay coil circuit causing contact 9 to be opened and the pump feed is interrupted. Second piston 31 will move into abutment with stop 34 when the maximum pressure is built up, the device is now in a left-hand end piston in which pressure accumulator 3 is charged to 90 bars, for instance.
With the pressure slowly dropping below 90 bars, spring 28 will displace first piston 24 to the right so that its end surface 40 will lift from the end surface 41 of second piston 31. Second piston 31, itself will, however, not move since second piston 31 is maintained in its position by friction member 36. Friction member 36 is constructed so as to keep the spring-loaded contact pin 33 in its open position.
With the pressure continuing to drop, spring 28 will displace first piston 24 still further to the right and head 30 approaches stop 39 of second piston 31. When the back rim of head 30 is in abutment with stop 39, spring 28 will displace the entire arrangement comprising first piston 24 and second piston 31 to the right. In the event of a further pressure decrease, contact pin 33 of microswitch 5 will follow this movement and the pump feed will be switched on again. This might, for instance, happen at an accumulator pressure of approximately 70 bars.
Accumulator 3 will now be charged up again to 90 bars, and head 30 will have to cover axial clearance x from its end surface 40 to end surface 41 of second piston 31. Only after clearance x has been covered--the pressure will have been increasing to approximately 90 bars during this time--will second piston 31 be able to be displaced again for another switching process.
It is, consequently, the purpose of the lost motion between second piston 31 and head 30 of first piston 24 to determine the width of the hysteresis, of approximately 20 bars in the example employed, in cooperation with spring 28 and friction member 36. As will be appreciated, once the device is constructed, the hysteresis may be selected by an appropriate choice of the spring characteristic of spring 28.
Connected in parallel to this portion of switching device 2 is another portion which engages via a lever 42 in a radial groove 43 of second piston 31. Lever 42 is pivoted on an axle 44 rigidly located in housing 1. The end portion 45 of lever 42 is constructed like a ball end and is arranged in second piston 31 such that the center of ball end 45 is situated in the vicinity of the axis of second piston 31 when ball end 45 is moving. The other end portion of lever 42 is in communication with an actuating member 46, which bears via a spring 48 against a third or pressure piston 47. In this arrangement, actuating member 46 is inserted in pressure piston 47 in such a manner that spring 48 keeps the head-like constructed end portion 49 in pressure piston 47 in abutment with the stop 50 of pressure piston 47. The end portion of lever 42 acting on actuating member 46 includes an oval opening 51, in which a pivot 52 attached to the end portion of actuating member 46 engages.
Provision of oval opening 51 ensures that lever 42 and axle 44 remain swivelling upon an admissible axial movement of actuating member 46 without the risk of the device being jammed.
Pressure piston 47 is sealingly slidable in housing 1, thereby separating a pressure chamber 53 from the remaining unpressurized space 54. To have a defined pressure chamber 53 available even in the illustrated inactivated position, a stop 55 is provided in housing 1 against which pressure piston 47 abuts when in its rest position. Pressure piston 47 is held in its rest position by a spring 56, spring 56 being disposed in a circular groove 57 in pressure piston 47 and bearing against a stop 58 in housing 1.
Chamber 53 is connected to return line 4, which in turn is connected to the outlet valve of user component AS. Via the suction connection 59, pump 12--with motor 10 running--delivers the pressure fluid from pressure chamber 53 to pressure accumulator 3 through a check valve 60 opening against the pressure of pressure accumulator 3. Suction connection 59 communicates with pressure fluid reservoir 16 via a check valve 61. In this arrangement, spring 62 of check valve 61 is constructed such that a pressure of, for instance, 2 bars at the most is allowed to develop in pressure chamber 53. If fluid is fed via line 4 which is pressurized to a higher extent, check valve 61 will open and transmit the surplus pressure fluid to pressure fluid reservoir 16.
When the outlet valve of the user components AS is opened during a detected impending skid, brake pressure fluid under pressure is released from the brake circuit into line 4 thereby developing pressure of approximately 1 to 2 bars in pressure chamber 53. Assuming that a pressure of about 80 bars prevails in pressure accumulator 3 at the time the user component was switched on, head 30 will, on the one hand, be spaced a specific amount from end surface 41 of second piston 31, but will, on the other hand, also have a specific clearance from stop 39.
Caused by the pressure in pressure chamber 53, pressure piston 47 will be displaced to the left, actuating rod 46 will move lever 42, and the forward movement of pressure piston 47 will be transformed into a backward movement of second piston 31 due to the point of rotation 44 of lever 42. Since, however, ball end 45 of lever 45 has a slight axial clearance in radial groove 43, ball end 45 will be moved into abutment with the side 63 of groove 43 only after a slight forward movement of pressure piston 47 and will displace second piston 31 to the right side with pressure piston 47 continuing to move. This results in an intervention in the switching range of the upper portion of switching device 2 and an immediate switching on of motor 10 and, hence, pumps 11 and 12 by closing microswitch 5.
When this occurs, not only will pump 11 deliver pressure fluid from pressure fluid reservoir 16 to accumulator 3, but pump 12 will also supply the pressure fluid prevailing in pressure chamber 53 to pressure accumulator 3.
The pressure in pressure accumulator 3 will now rise up to 90 bars, and at that moment, end surface 40 of head 30 will abut end surface 41 of second piston 31 again and will displace second piston 31 to the left against the force of lever 42, thus switch off microswitch 5 again and interrupting the pump feed. If pressure fluid is continued to be fed to pressure chamber 53 via return line 4, pressure piston 47 will continue to be displaced to the left; however, in doing so, pressure piston 47 will not be able to transmit its forward movement to lever 42. Nevertheless, in order to be in a position to execute a forward movement, spring 48 is compressed due to the force acting on pressure piston 47. According to this, switching device 2 does not only have the function of pressure control, but pressure chamber 53 serves at the same time as a volume accumulator for pump 12.
If the pressure in pressure accumulator 3 drops in this position of switching device 2 on account of the higher pressure fluid demand by the connected user components, first piston 24 will move away from microswitch 5 to the right due to the force of spring 28. However, in this working position second piston 31 will not remain in its position in which it was shifted by first piston 24, since the force of spring 48 acts on second piston 31 via actuating member 46 and lever 42 and keeps second piston 24 in abutment with head 30. Consequently, microswitch 5 will move to the right upon a slight movement of first piston 24 and will switch on again at once. The pressure will be immediately re-increased to 90 bars.
Thus, the entire switching device 2 has the following effect.
Fluctuations of pressure up to 20 bars, for example, are permitted in pressure accumulator 3 under normal operating conditions, controlled by first piston 24 and second piston 31 fastened to first piston 24 in the sense of a lost motion clutch. This is absolutely sufficient for feeding the connected user component HV. Motor M is put into operation only rarely due to such a hysteresis width which admittedly is comparatively large. If, however, the other user component AS is switched on requiring a higher and considerably more constant pressure level, the arrangement composed of pressure piston 47, actuating member 46 and lever 42 will influence the remainder of switching device 2 in such a manner that the hysteresis width will be reduced to a few bars (1 to 2 bars).
Switching devices of this type are particularly advantageous for use in vehicles with antiskid control systems, the user component AS. A hydraulic brake force boosting unit, allowing comparatively great fluctuation of pressure, may be provided as a first user component HV connected to pressure accumulator 3. If, however, an antiskid control operation is provided with the help of the pressure fluid in pressure accumulator 3, the accumulator pressure is required to be relatively constant for ensuring a perfect control operation. This object may be achieved in an easy way by the described embodiment of the switching device in accordance with the present invention. The increase of the switching-off threshold may be determined by the proportioning of spring 48. It is, of course, also possible to realize the hydraulic modes of operation described herein by an electromechanic switching device or likewise by an electronic switching device. But these switching devices would require the translation of the hydraulic pressure signals into electric signals, which has a certain expenditure as a result. The described switching device may be used without any difficulties and without entailing a particularly great expenditure of power and electrical outfit in any pressure system, in which various user components are connected to one pressure accumulator and in which these various user components expect different minimum feed pressures from the accumulator.
While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims. | Pressure control systems for a pressure accumulator are known in which the pressure accumulator is fed by a controllable pump. When the pressure accumulator serves to supply at least two user components each requiring a different minimum feed pressure for correct operation, it is desired to provide a pressure control system which is safe in its mode of operation, simple in its construction and needs little energy for maintaining the feed pressure. This is accomplished according to the present invention by a switching device which switches on the pump when the accumulator pressure falls below a first threshold value corresponding to lowest minimum feed pressure of the two user components and which switches off the pump when the accumulator pressure reaches a second threshold value corresponding to the highest minimum feed pressure of the two user components with the switching device responding to the return pressure from that one of the two user components having the highest minimum feed pressure when operated to raise the first threshold value to approximately the second threshold value. | 1 |
This application is a continuation of application Ser. No. 073,898, filed July 13, 1987 abandoned, which in turn is a continuation of Ser. No. 689,554, filed Jan. 7, 1985, both abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a beer, particularly low-alcohol or alcohol-free beer, and to a method of producing such beer.
A plurality of methods of manufacturing low-alcohol or alcohol-free beers have been known in the art, in which from beer, produced by conventional brewing process and having a normal alcohol content, a portion of alcohol is withdrawn. In the method disclosed in DE-OS 1,442,238 alcohol is evaporated from beer in a thin layer-evaporator at the temperatures below 70° C.
In the similar method disclosed in DE-AS 1,266,266 beer is firstly subjected to an atomization evaporation in vacuum and then the residuals are reblended and impregnated with carbonic acids.
Methods for an adsorptive alcohol removal are disclosed, for example in DE-OS 2,405,543. A method of producing of alcohol-free beer by a reverse osmosis is disclosed in DE-OS 2,323,094.
Furthermore, methods of manufacturing of alcohol-free beer by breaking a fermentation or boiling of beer in brewing pans have been also proposed. Finally, there has been also a possibility to remove alcohol from beer by high-pressure extraction with fluid CO 2 .
All known methods for the alcohol removal from beer have the disadvantage that, besides the reduction of the alcohol content which is important for the bodied beer, other beer ingredients which affect a total sensitive impression of beer and therefore the quality of low-alcohol or alcohol-free beer were removed. It has been also found that the reverse osmosis and high-pressure extraction methods have required an expensive and troublesome equipment and have involved a number of technical difficulties which have not been overcome in practice.
Also full beers, diet beers, strong beers and beers of low original wort content with an alcohol content between about 1.5 and 6.0 weight percent depending on the raw materials and fermentation conditions used can be improved in their bodyness and other taste qualities.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved beer, particularly an improved alcohol-free or low-alcohol beer.
It is another object of this invention to provide a simple inexpensive method of manufacturing beer of improved bodiness which can be adapted to produce such improved beer from malt, hop and water as the only raw materials.
These and other objects of the present invention are attained by a beer, particularly a low-alcohol or alcohol-free beer, comprising from 0.3 to 2.3 volume percent of glycerol whereby the full body of the beer is improved.
The glycerol content in the beer may be between 0.4 and 1.5 volume percent, preferably between 0.5 and 1.2 volume percent.
With conventional brewing methods during the fermentation of the wort there is produced besides ethyl alcohol also a small amount of glycerol which, however, in conventional beer does not exceed 2 g/l. It is also known that certain special yeasts, for example zygosaccharomyces acidifaciens Nickerson,* Saccharomyces rouxii and Saccharomyces mellis besides the production of alcohol, transform up to 50% of the consumed carbohydrate into glycerol. These yeasts, however, up to now have not been tested for or used in beer brewing.
It has been surprisingly discovered that a low-alcohol or alcohol-free beer having a glycerol content between 0.3 and 2.0 volume percent not achievable by conventional beer brewing methods, has such an improved full taste and body that it can hardly be distinguished from beers of non-reduced alcohol content, so that it is desirable to produce beer having such an glycerol content.
The overall glycerol content in the beer may consist of glycerol produced in situ by a fermentation of a wort in the presence of a yeast producing an increased glycerol content or may consist predominantly of glycerol introduced to a wort or a beer before or after an alcohol removal.
The beer may further comprise 0.05 to 0.5 volume percent of at least one type of sugar alcohol.
The volume percent of sugar alcohol may be 0.1 to 0.3.
The sugar alcohol may be erythritol and/or d-arabitol.
The objects of this invention are further attained by a method of producing beer, particularly a low-alcohol or alcohol-free beer by fermentation of a wort, an optional subsequent alcohol removal and the addition of glycerol, or by carrying out the fermentation under conditions adapted to an increased glycerol formation so as to obtain a glycerol content in the beer between 0.3 and 2.0 volume percent.
In a method for producing a low-alcohol beer from a beer made in accordance with a conventional brewing process and having an alcohol content above 1.5 weight percent after reducing the alcohol content to between 0.5 and 1.5 weight percent by evaporation, reverse osmosis, alcohol adsorption or pressure extraction, and eventual dilution and recarbonization, the glycerol content in the beer is adjusted to be between 0.3 and 1.0 volume percent.
In a method for producing a substantially alcohol-free beer from a beer made in accordance with a conventional brewing process and having originally an alcohol content above 1.5 weight percent after reducing the alcohol content to values below 0.5 weight percent and preferably below 0.1 weight percent, by evaporation, reverse osmosis, alcohol adsorption or pressure extraction, and optional redilution and recarbonization the glycerol content is adjusted to between 0.5 and 1.8 volume percent.
The glycerol may be added to the beer as a glycerol-containing liquid, before or after the alcohol removal in the wort.
Said liquid may be a beer with an adequate glycerol content.
If the beer is subjected to a thin-layer-evaporation in vacuum, a glycerol-containing liquid may be added to the evaporated beer before or after a possible redilution of the beer.
When the fermentation of the wort is carried out in the presence of an osmophilic yeast, the fermentation conditions should be selected such that there are obtained beer-typical conditions and an increased production of glycerol instead of ethyl alcohol. To this purpose specifically processed brewing malts may be used. It is also proposed herein to add sugars fermentable by osmophilic yeasts, particularly starch sugar, because such yeasts during fermentation cannot consume most of the carbohydrates of the malt. In this case the added sugar represents the main carbon source for the anaerobic fermentation. Besides other beer-type metabolism products the obtained ratio between glycerol production and alcohol production can be about 1: 0.8-0.9. In such a fermentation there are produced, based on glycerol, about one third of its amount of acetic acid and about 4% of its amount of lactic acid, both of which during alcohol removal in vacuum are evaporated from the beer together with the ethyl alcohol so that the flavour qualities of the beer are not affected.
After fermentation the beer obtained before or after an alcohol removal may be blended with beer produced by other methods and/or subjected to a maturation and/or an afterfermentation with the same or another yeast.
The technically and economically simplest method of producing an improved beer comprises the addition of glycerol or a glycerol-containing liquid to the beer produced by fermentation of the wort, before or after an alcohol withdrawal, whereby the body and flavour qualities of the beer are substantially improved.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example I
A commercial high quality Pilsen type beer of mild bitterness produced by conventional methods and having an original wort content of 12 weight percent, a real extract content of 4 weight percent, an alcohol content of 4 weight percent and a bitterness value of about 25 EBC-units is subjected to vacuum distillation to produce, on the one hand, a low-alcohol beer with an alcohol content of 1.5 weight percent and on the other hand, an alcohol-free beer with an alcohol content below 0.05 weight percent. There is added 0.5 volume percent of pure glycerol to the low-alcohol beer, and 0.85 volume percent of pure glycerol (Merck 4093, EWG-Ni-E422) to the alcohol-free beer. Thereafter both trial beers are rediluted with water to their initial volume and recarbonized. In a tasting trial both alcohol-reduced beers as compared to said commercial beer, were superior in scent, practically the same in taste and bodyness and had with the same foam appearance a better foam retention and foam adherence.
Example II
For the production of an alcohol-free beer corresponding in taste to the commercially available Pilsen type beer utilized in Example I, there is prepared from a malt having an albumen content of 16 weight percent, a color of 6 EBC, a color of boiled wort of 11 EBC (based on congress wort), a viscosity of congress wort of at least 1.75 mPas, a coarse and fines difference of 3 weight percent, an albumen solution degree of 44% and content of soluble nitrogen in 100 ml of 12% of laboratory wort of above 130 mg, in accordance with a two-step mashing method using a temperature sequence of 50°/75°/77° C. for obtaining a low apparent final fermentation degree of about 35% a wort having an original wort content of 11 weight percent and bitterness value of 48 EBC-units. Said wort is fermented by pressure fermentation with a bottom-fermented yeast at fermentation temperatures between 15° and 18° C. up to final fermentation (real extract content 8 weight %, alcohol content 1.5 weight percent) and the beer is then subjected to a final warm maturation phase for 24 hours. The obtained beer is then dealcoholized in a vacuum rotation evaporator at a pressure of about 15 mm Hg and temperatures of about 30° C. to a residual alcohol content of 0.1 weight percent. The residuals are rediluted with water to a real extract content of 4% and added with 0.65 volume percent of glycerol and recarbonized. The alcohol-free beer obtained, as compared to the commercial beer used in example 1 is somewhat weaker in scent, however, much better in taste and as good in bitterness. The foam retention and foam adherence of this beer are better.
Example III
An alcohol-free beer is produced by the method of Example II, but using top-fermented yeasts at fermentation temperatures between 20° and 25° C. This alcohol-free beer due to its higher content of fermentation side products is clearly better in scent and is as good in other qualities, as compared to the commercial beers of example 1. Trial beer is assessed altogether somewhat better as the commercial beer used in example I.
Example IV
A wort produced from the malt of Example II according to the same two-step mashing process and having an original wort content of 14 weight percent (8 weight percent from the malt addition and 6% from the addition of starch sugar) and a bitterness value of 48 EBC-units is then fermented by pressure fermentation at a fermentation temperature of about 25° C. in the presence of Zygosaccharomyces acidifaciens Nickerson up to a final fermentation (based on this yeast) with an real extract content of 9 weight percent, an alcohol content of 1.15 weight percent, a glycerol content of 1.35 weight percent, an acetic acid content of 0.45 weight percent and a lactic acid content of 0.05 weight percent. The obtained product undertakes a warm maturation phase for 24 hours, then is adjusted in a vacuum rotation evaporator to a residual alcohol content of 0.1 weight percent and residual acid content of 400 mg/l, rediluted to a real extract content of 4.5%, and recarbonized. With respect to the real extract content it should be noted that 1.35 weight percent of glycerol corresponds to a real extract content of about 1 weight percent so that in the absence of glycerol the extract content prior to dealcoholizing would be 8 weight percent and after the redilution would be 4 weight percent. This beer also has a Pilsen character, and in its bodiness and its other taste properties is equivalent to the commercial beer of Example I.
Example V
A commercial Pilsen type beer having an original wort content of 11.4 weight percent, real extract content of 3.8 weight percent and an alcohol content of 3.7 weight percent is blended with a beer produced by the malt and the mashing method of Example II having an original wort content of 15 weight percent, a real extract content of 13 weight percent and an alcohol content of about 1 weight percent, and with water in a weight ratio 3:1:4. The obtained mixture having an original wort content of 6.15 weight percent, a real extract content of 3.05 weight percent and an alcohol content of about 1.5 weight percent is thereafter adjusted in a vacuum rotation evaporator to a residual alcohol content of about 0.1 weight percent, rediluted with water to its initial volume, admixed with 0.65 volume percent of glycerol, and recarbonized. The resulting beer has Pilsen character and is better in scent, bodiness and bitterness, as the commercial beer used in example V while the other taste characteristics of this beer are the same. The foam of the trial beer is more finely porous and has a better retention and adherence. The trial beer was preferable by the tasting panel.
Example VI
A beer of lower original wort content produced in accordance with the method of Example I from the same raw material quantities and qualities (original wort content 8 weight percent, real extract content 2.7 weight percent, alcohol content 2.7 weight percent, bitterness value 25 EBC units) is admixed with 0.5 volume percent of glycerol. The obtained beer has Pilsen character and its scent and flavor are better than of those of the commercial beer of example I, while in the foam quality, bitterness and bodyness there exist no significant differences. Again the trial beer was preferred by the tasting panel.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of beers and methods of producing the same differing from the types described above.
While the invention has been illustrated and described as embodied in a beer and a method of making the same, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A beer containing 0.3 to 2.3 volume percent of glycerol and a method of manufacturing said beer in which glycerol is added to the beer produced by a conventional brewing method or the fermentation is carried out in the presence of a yeast producing a sufficient glycerol content of the beer without glycerol addition. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to U.S. Provisional Patent Application No. 61/502,665 filed on Jun. 29, 2011 (Attorney Docket No. TI-71080 PS) titled “Connection Setup for Low Energy Wireless Networks;” which is hereby incorporated herein by reference.
BACKGROUND
[0002] Bluetooth Low Energy (BLE) is a wireless radio technology, aimed at new, principally low-power and low-latency applications for wireless devices within a short range (up to about 160 feet). BLE networks are particularly well-suited for a wide range of applications and smaller form factor devices in the healthcare, fitness, security and home entertainment industries. As its name implies, BLE is intended for such energy-constrained applications as a sensor or a disposable device, particularly those that transmit relatively little data and do so infrequently. BLE was designed to enable wireless connectivity with small devices running for extended periods of time on, for example, a coin cell battery. While an objective of networks that utilize BLE technologies is robust and secure delivery of information, saving battery power is also a concern.
SUMMARY
[0003] Various techniques for connection setup for Bluetooth Low Energy (BLE) devices are disclosed. The various embodiments save power. In one example, a BLE master generates and transmits a packet that includes timing information about its scan interval and scan window. For example, an apparatus may include a controller configured to cause a wireless transceiver to send and receive wireless packets. The controller is configured to receive a packet from another wireless device. The packet specifies a scan window length, a scan interval, and a start time. Based on the start time, scan interval, and a current time, the controller is configured to compute when a subsequent scan window will begin and the wireless transceiver does not transmit advertising packets until the subsequent scan window begins.
[0004] Another embodiment is directed to a method that includes receiving a wireless packet that specifies a scan window length, a scan interval, and a start time. Further, based on the start time, scan interval, and a current time, the method includes computing when a subsequent scan window will begin.
[0005] An apparatus preferably includes a controller configured to cause a wireless transceiver to send and receive packets. The controller is configured to generate a scan update packet that specifies a scan window length, a scan interval, a start time and an end time. The scan window length and scan interval are valid between the start time and the end time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0007] FIG. 1 shows a master device in wireless communication with a slave in accordance with various embodiments;
[0008] FIG. 2 shows an illustrative implementation of a slave or master device in accordance with various embodiments;
[0009] FIG. 3 illustrates advertising ADV_IND packets and responses in accordance with various embodiments;
[0010] FIG. 4 illustrates advertising ADV_DIR_IND packets and responses in accordance with various embodiments;
[0011] FIG. 5 shows a method in accordance with various embodiments in which a scan window and scan interval are estimated in a calibration process implemented on a slave device in accordance with various embodiments;
[0012] FIG. 6 illustrates a time line depicting the calibration process in accordance with various embodiments;
[0013] FIG. 7 shows a method in which a slave device uses the estimates from the method of FIG. 5 in accordance with various embodiments;
[0014] FIG. 8 illustrates a packet usable by a master device to specify to slave devices the scan window and scan interval in accordance with various embodiments;
[0015] FIG. 9 depicts a timeline example in which the current time is in the dead time between scan windows in accordance with various embodiments;
[0016] FIG. 10 depicts a timeline example in which the current time is within a scan window in accordance with various embodiments; and
[0017] FIG. 11 shows a method in which a slave device estimate uses scan update information provided by a master device in accordance with various embodiments.
NOTATION AND NOMENCLATURE
[0018] Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. The terms “packet” and “frame” are used interchangeably in this disclosure.
DETAILED DESCRIPTION
[0019] The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
[0020] In some wireless networks, wireless devices set up connections with each other to facilitate data transfer. This disclosure focuses on BLE networks, but the scope of the disclosure and the claims applies to other network types as well. The problem with the connection setup process is that a BLE slave device spends a great deal of time in the connection setup phase. In general, a BLE device may operate in different modes depending on required functionality. The main modes of operation include the advertising mode, the scanning mode, master device mode, and slave device mode. In advertising mode, the BLE device periodically transmits advertising packets and may respond with more information upon request from other devices. In the scanning mode, a BLE device listens for and receives advertising packets transmitted by other devices and may request additional information from the originator of an advertising packet. A slave device connects to a single master, but a master may connect to multiple slave devices simultaneously.
[0021] To establish a connection, a first BLE device transmits an advertising frame. A second BLE device responds to the advertising frame and may request additional information. If additional information is requested, the first device transmits the requested information. The connection can then be established with the first device being the slave device and the second device being the master device. In this disclosure, references to “slave device” refer to the BLE device that sends out the advertising packets, and the “master device” is the BLE device that receives and responds to the advertising packets.
[0022] A slave device transmits advertising packets such as advertising indicator (ADV_IND) and advertising directed (ADV_DIRECTED_IND which is the same as ADV_DIR_IND in FIG. 4 ) packets. And ADV_DIRECT_IND packet is directed to a specific master device and contains the medium access control (MAC) address of the target master device. The ADV_DIRECT_IND packet indicates that the slave device wants to connect to that specific master device to establish a connection. The ADV_IND packet is not specific to any particular master device and indicates the presence of the slave device.
[0023] FIG. 1 shows two wireless devices 10 and 20 . Wireless device 10 is a master device and wireless device 20 is a slave device. As noted above, to establish a connection between the master and slave devices 10 , 20 , the slave device 20 transmits an advertising packet which, if received by the master 10 , indicates the presence of the slave device 20 to the master device. The master device 10 may respond with a scan request (SCAN_REQ) packet. The slave device 20 responds to the SCAN_REQ with a scan response (SCAN_RSP) packet to provide additional data if necessary before establishing the connection. The master and slave devices 10 , 20 thus engage in information exchange before establishing a connection.
[0024] FIG. 2 illustrates a block diagram of a slave device 20 . As shown, the slave device 20 includes a controller 22 , a transceiver 24 , an antenna 26 , and a battery 28 . The battery 28 provides electrical power to the controller 22 and transceiver 24 . The transceiver 24 accepts signals from the controller 22 to transmit wirelessly via antenna 26 . Similarly, wireless signals received by the antenna 26 are provided by the transceiver 24 to the controller 22 for processing. The transceiver 24 thus is capable of bi-directional data communications with another wireless device such as a master device 10 . The controller 22 may comprise a processor executing software. The controller 22 preferably performs some or all of the functionality described herein as attributed to the slave device 20 . The architecture depicted in FIG. 2 may be used as well to implement the master device 10 .
[0025] In the BLE protocol, channels 37 , 38 , and 39 (also referred to as a “channel index”) are dedicated for use in transmitting advertising packets and the associated responses. The master device 10 listens on each advertising channel for a scan window interval of time (“scanWindow”). The scan interval (“scan Interval”) is defined as the time between two consecutive scan windows. During each scanInterval, the master device 10 listens for the scanWindow interval unless there is a scheduling conflict. The master device replies to ADV_IND or ADV_DIRECT_IND packets that it receives during the scanWindow interval.
[0026] FIGS. 3 and 4 illustrate examples of a BLE master response to advertising packets from a BLE slave. FIG. 3 illustrates the slave device 20 transmitting an ADV_IND packet in each of the three advertising channel indexes 37 - 39 dedicated for such purpose as noted above. Transmitting an advertising packet in each of the three dedicated advertising channel indexes is referred to herein as a “round” of advertising packets. In FIG. 3 , the master device 10 does not respond to the advertising packets 30 and 50 in channel indexes 37 and 39 , but does reply to the advertising packet 40 in channel index 38 with a scan request (SCAN_REQ) frame 42 requesting additional information from the slave device 20 in order to establish a connection. The slave device responds with a scan response (SCAN_RSP) frame 44 to provide all such requested information.
[0027] As shown in the example of FIG. 3 , the ADV_IND advertising packets 30 , 40 , and 50 are transmitted, one after the other but at an interval of at most 10 msec. Thus, a round of advertising packets takes at most 30 msec.
[0028] The scan window in which the master device 10 listens for advertising packets is a portion of the scan interval. During the remaining portion of the scan interval, the master device 10 does not respond to advertising packets from slave devices and thus that portion of the scan interval is referred to herein as “dead” time. If the slave device starts sending advertising packets after the scanWindow interval has ended (i.e., during the dead time), then, during the portion of the scan interval that is outside the scanWindow the slave device may transmit as many as 3(scanInterval−scanWindow)/30 msec advertising packets that will go unanswered by a master device. These advertising packets thus waste energy by the slave device.
[0029] In FIG. 4 , the slave device sends directed advertising frames (ADV_DIR_IND) to a specific master device. A pair of master and slave devices may have already connected at some prior time; however, the connection may have been lost or ended for whatever reason. At any rate, the slave device wants to reestablish the connection to the same master device. In the example of FIG. 4 , the master device does not reply to the first two ADV_DIR — IND frames 60 and 70 but does reply to the third ADV_DIR_IND frame 80 with a connection setup request frame (CONN_SETUP_REQ) 84 conveying connection specific information to slave.
[0030] As shown in the example of FIG. 4 , the ADV_DIR_IND advertising packets 60 - 80 are transmitted with all three packets transmitted in a time period of 3.75 msec. Thus, a round of master-specific advertising packets takes 3.75 msec. If the slave device starts sending advertising packets after scanWindow interval has ended, then the slave device may transmit as many as 3*(scanInterval−scanWindow)/3.75 msec ADV_DIR_IND frames that will go unanswered by a master device thus wasting energy.
[0031] The examples above illustrate that there is a portion of each window interval (the “dead” time) in which a slave will expend energy to transmit advertising frames that go unanswered. In accordance with the preferred embodiments of the invention, the slave device does not transmit as many advertising frames during the period of time that the master device is not likely to respond to the slave device's advertising frames. Various embodiments of the invention will now be described to improve the connection setup for slave devices. Such embodiments result in a power savings.
Scan Interval Estimation by Slave Device
[0032] In one embodiment, the slave device 20 estimates the scan window and scan interval time periods based on responses, or lack thereof, from a master device to advertising packets. The slave device then uses the estimated scan window and scan interval values to establish future connections with the master device 10 .
[0033] FIG. 5 illustrates a method 100 for estimating the size of the scan window and scan interval for a given master. The actions depicted in FIG. 5 may be performed in the order shown, or in a different order. Further, two or more of the actions may be performed in parallel rather than serially. The method depicted in FIG. 5 is a calibration routine performed by the slave device 20 one time, although the slave device can perform the calibration routine more than once as desired. At the end of the calibration routine depicted in FIG. 5 , the slave device will have computed an estimate of the master's scan window and scan interval.
[0034] Referring briefly to FIG. 6 , three scan windows 115 , 117 , and 119 are depicted. The scan interval also is shown. Reference will be made to FIG. 6 as the method 100 of FIG. 5 is explained. At 102 , the slave device 20 begins transmitting ADV_IND packets. In FIG. 5 , references to transmitting an advertising packet preferably means transmitting a round of advertising packets in the various advertising channels. The first such packet is shown in the example of FIG. 6 at 120 . The slave device 20 will receive a response (e.g., SCAN_REQ) from a master device 10 if the ADV_IND packet happens to have been transmitted while the master device is in its scanning mode defined by its scan window. However, the slave device 20 still will not know in which portion of the scan window the ADV_IND packet was sent. On the other hand, the slave device 20 may have sent the ADV_IND packet during the “dead” time between scan windows in which the master device will not respond to ADV_IND packets. And in that situation, the slave device will not know in which portion of the dead time it sent the ADV_IND packet. All that the slave device 20 can determine is whether the ADV_IND packet was sent during the dead time or during a scan window.
[0035] If a response to the ADV_IND packet is not received ( 104 ), which will be the case for the ADV_IND packet 120 in FIG. 6 , then the slave device 20 determines that the advertising packet was sent during the dead time. The slave device 20 is attempting to find the beginning of the next scan window and thus the slave device repeatedly sends additional advertising packets until a response is received from a master device, which will occur as a result of the slave device transmitting advertising packet 122 at the beginning of scan window 117 .
[0036] When the slave device 20 finally does receive a response (e.g., SCAN REQ) from a master, the slave device determines that it is now in a scan window. As such, the slave device at 106 records the time that the response was received or that the advertising packet 122 was transmitted. The recorded time is an estimate of the beginning of the scan window 118 as well as the beginning of the scan interval. In an alternative embodiment, the slave device may start a timer to measure the length of the scan window and a separate timer to measure the length of the scan interval.
[0037] Now that the slave device 20 has found the beginning of the scan window and scan interval, the slave device continues transmitting advertising packets at 108 in an attempt to find the end of the scan window (specifically the end of scan window 117 in FIG. 6 ). As long as responses to advertising packets are received ( 110 ), the slave device determines that the master is still in the scanning mode (i.e., still in the scan window). In the example of FIG. 6 , master responses are received for advertising packets 124 , 126 , and 128 .
[0038] As soon as the slave device fails to receive a response for an advertising packet, then the slave device determines that it has left the scan window and has found the beginning of the dead time. In FIG. 6 , the slave device will not receive a response for advertising packet 130 . Once that determination is made, the slave device 20 again records the time ( 112 ) which will indicate the end of the scan window, or stop the scan window timer if a timer is used. The slave device 20 can now estimate the length of the scan window by subtracting the starting time from the ending time, or noting the time value on the timer.
[0039] The slave device 20 continues transmitting advertising packets at 114 in an attempt to find the end of the dead time which is also the beginning of the next scan window 119 . As long as no responses are received, ( 116 ) the slave device determines that it is still in the dead time, and continues sending advertising packets. The last advertising packet the slave device will transmit in the dead time and thus without a response is packet 132 . The next packet 134 is transmitted in the next scan window 119 and thus a response will be generated by the master device and received by the slave device. At that point, the slave device 118 again records the time which indicates the end of the scan interval, or stops the scan interval timer. The length of the scan interval can be estimated by subtracting the starting time as recorded at 106 (for packet 122 ) from the ending time recorded at 118 . Alternatively, the scan interval may be the time value in the scan interval timer if such a timer is used.
[0040] The estimation process described above is respect to a particular master device. If there is more than one master device in wireless vicinity of the slave device, then the slave device can distinguish such master devices based on the responder address (either on the scan request or another frame). The slave device may maintain different tags for each master device for this purpose.
[0041] The scan window and interval can be estimated as the maximum of the measured time values over all of the advertising channels. Separate statistics for each channel can also be used if desired. Further, the estimates of the scan window and scan interval can be increased to improve accuracy. For example, for a scanWindow value of 100 msec and interval between ADV_IND packets within a round of packets in the various advertising channels, the maximum error that can be made is 30 msec. However, if the interval between ADV_IND packets is reduced to 5 msec then the maximum error is about 15 msec. This implies that the accuracy can be increased from 70% to 85%. The estimate for the scan window may be increased from that determined in the process of FIG. 5 by the amount of the maximum error.
[0042] FIG. 7 illustrates a method 140 for how the slave device 20 uses the estimated scan window and scan interval to determine when to cease transmitting ADV_IND packets. The actions depicted in FIG. 5 may be performed in the order shown, or in a different order. Further, two or more of the actions may be performed in parallel rather than serially.
[0043] At 142 , the slave device 20 sends a round of advertising packets. In the case of BLE, this means the slave device sending a single ADV_IND packet in each of the three advertising channels 37 - 39 . If, as determined at 144 , the slave device receives a scan request response (SCAN_REQ) for any of the ADV_IND packets, then a connection subsequently is established at 146 . However, if the slave device does not receive a scan request response for any of the ADV_IND packets, then at 148 , the slave device determines whether the estimated scan window is greater than the time required to transmit a round of ADV_IND packets less the time required to transmit a single ADV IND packet in a single advertising channel. If the determination is “no” at 148 , then control loops back to 142 and the slave device sends another round of advertising packets.
[0044] If, however, the estimated scan window is indeed greater than the time required to transmit a round of ADV_IND packets less the time required to transmit a single ADV_IND packet in a single advertising channel, then at 150 the slave device temporarily ceases transmitting ADV_IND packets. Specifically, the slave device may stop transmitting advertising packets for a period of time equal to the estimated scan window minus the time required to transmit a round of ADV_IND packets less the time required to transmit a single ADV_IND packet in a single advertising channel. After the expiration of the time period in which the slave device ceases transmitting advertising packets, the slave device continues transmitting advertising packets in case the master device is now in the scan window and ready to receive advertising packets.
Master-Initiated Update of Scan Interval Information
[0045] Another embodiment for reducing the number of advertising packets the slave device transmits is for the master device to advertise its scanning intervals at the time of connection setup or during a connection event via scan update procedures.
[0046] For example, the master device may send scan update frames at different channel advertising indexes during its scanWindow intervals before a connection to a slave is established. FIG. 8 illustrates a frame 200 format that can be used in this regard. The frame may be an ADV_SCAN_IND frame transmitted by the master device during its scan windows. Alternatively, a previously reserved frame type could be used such as frame types 0111 or 1111.
[0047] The frame illustrated in FIG. 6 is a scan update frame that is generated by the master device 10 and transmitted to the slave device 20 . The illustrative frame 200 shown in FIG. 8 includes various fields including a preamble field 202 , an access address field 204 , a header field 206 , an advertising address (AdvA) field 208 , scanWindow field 210 , a scanInterval field 212 , a scanParametersStartTime field 214 , a scanParametersEndTime field 216 , and a cyclic redundancy code (CRC) field 208 .
[0048] The preamble field 202 includes information used for radio synchronization. The access address field 204 is used for physical link identification. The header field 206 includes the type of Protocol Data Unit (PDU). For example, the PDU type may be set to 0110 to indicate the ADV_SCAN_IND packet type. The AdvA field 208 is used for the master address. The CRC field ensures correctness of the data in PDU.
[0049] The scanWindow field 210 and scanInterval 212 include values of the lengths of the scanWindow and scanInterval, respectively, for the master. The scanParameterStartTime field 214 and scanParametersEndTime field 216 include the starting and ending time for which the corresponding scanWindow and scanInterval values are valid.
[0050] The master device 10 may transmit scan update frames to slave devices 20 that are currently connected to the master device. The master device 10 may send such update frames because, for example, new slaves may have joined the network and the master device needs to update the scan intervals. This will take precedence over the previously setup scan intervals. Such update frames be transmitted during data channels (not advertising channels) and, as such may be a new frame type previously designated as a reserved frame type (e.g., 00b). Alternatively, an existing frame type could be used (e.g., LL control PDU) in which the sub-type is scan_update information. In one example, the opcode field in the header of the LL control PDU may define a new subtype (e.g., 0x0E) which is designated as LL_SCAN_UPDATE. In any case, the payload of the scan interval update frames includes scanWindow, scan Interval, scan ParameterStartTime, and scan ParametersEndTime.
[0051] Any future connection setup between the master device and a slave device will be based on the information previously provided to such slaves in any of the aforementioned update frames (e.g., frame 200 ). FIG. 9 illustrates a time line having a start time (designated as “S” in FIG. 9 ) specified by the scanParameterStartTime field in packet 200 , an end time (“E”) specified by the scanParametersEndTime field in packet 200 , and a current time (“CT”). The values of S and E are provided in update frame (e.g., frame 200 ). The time line illustrates scan windows 250 and the scan interval (designated as “SI”). The current time (CT) is shown in the example of FIG. 9 in between two scan windows and thus in the dead time in which the master device is not listening for slave device advertising packets. FIG. 10 provides a time line example in which the current time (CT) is located within a scan window 250 .
[0052] A slave device can estimate the start of the master device's scanWindow 250 in the case of the current time being in the dead time between scan windows. The current time and the scanParametersStartTime (S) can be used to calculate the number of scanIntervals (SIs) that have elapsed since the start time up to the current time. FIGS. 9 and 10 show an elapsed time interval (ETI) which is computed as:
[0000] ETI =└( CT−S )/ SI┘*SI
[0053] The time remaining from the immediately preceding scan window 250 until the current time is shown in FIGS. 9 and 10 as REM and is computed as:
[0000]
REM=CT−[S+ETI]
[0054] The remaining time (REM) is then compared to length of the scan window (SW) provided in the update frame. If REM is greater than scanWindow (which is the case in FIG. 9 ), then the slave device preferably waits until the start of the next scan window, which will occur at (CT+SW−REM) and is shown in FIG. 9 as TTNSW (time to next scan window). In the case of FIG. 10 , REM is less than scanWindow which indicates that the current time is in the middle of a scan window. In this case, the slave device sends ADV_DIRECT_IND (or ADV_IND) frames to the master device to which it was previously connected.
[0055] FIG. 11 illustrates a corresponding method 260 . The actions depicted in FIG. 11 can be performed in the order shown or in a different order and can be performed serially or in parallel.
[0056] At 262 , the slave device 20 computes ETI as floor((CT−S)/SI)*SI. At 264 , the slave device computes REM as CT−[S+ETI]. At 266 , the slave device 20 determines whether REM is greater than SW (scan window length). If REM is less than SW, then at 268 the slave device transmits advertising packets.
[0057] If, however, REM is greater than SW, then at 270 the slave device computes NSW as C+SI−REM and then waits at 272 for the NSW period of time to ensure that the slave device is then in the master's scan window. At 274 , after waiting NSW time, the slave device transmits advertising packets.
[0058] The maximum latency for connection setup is (SI−SW). During this interval though, the slave device 20 preferably does not need to send ADV_IND or ADV_DIRECT_IND frames to setup a connection. The slave device may need three frames to establish a connection with the master device if REM<SW, assuming that there are no collisions for the sent frames.
[0059] Furthermore, it is possible that, due to a scheduling conflict the master device 10 may not be able to perform scanning during some scan windows. The master device can convey this information in the connection setup phase or during connection events via additional fields that can be added to packet 200 . In this scenario, the master can introduce a time offset and time off duration. The time offset indicates the start time within scanWindow interval that the time off duration starts. During the time off duration, the master may be serving other slave devices in the network (e.g., sending/receiving packets during already established connection events).
[0060] If the packet is conveyed during a connection setup phase, the time offset and time off are presumably for other slave devices in the network that does not include the current slave since connection has not yet been established. If the packet is conveyed during connection events, then the packet conveys the time offset and time off for other slave devices in the network that may include the current slave device. Inclusion of the current slave device would be to simplify the procedure at the master device and not send different packet payloads to different BLE slaves to convey scan updated parameters.
[0061] Note that additional fields may be added that can help/convey with finer granularity of scan intervals. The duration of the fields can change to accommodate the new fields added. For example, additional fields may specify that the scan interval comprises multiple scan windows of different durations and the duration of each such scan window. By way of an additional example, additional fields may specify that multiple alternating scan Intervals are implemented with their own start and end times.
[0062] In some embodiments, multiple packets can be sent to convey scan update information. This information can include additional time offset and time off field per slave device in the network or any other information that can help slave devices to know scan intervals. Under these scenarios, more data bits and/or additional packets that require scan update information could be included immediately following the packet type. This may accommodate scenarios where different slave devices have different connection intervals that simply “punch holes” in scanWindow interval.
[0063] The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | An apparatus includes a controller configured to cause a wireless transceiver to send and receive wireless packets. The controller is configured to receive a packet from another wireless device. The packet specifies a scan window length, a scan interval, and a start time. Based on the start time, scan interval, and a current time, the controller is configured to compute when a subsequent scan window will begin and the wireless transceiver does not transmit advertising packets until the subsequent scan window begins. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. §119(e) to U.S. Application No. 62/114,219, filed Feb. 10, 2015, the entire content of which is incorporated into the present application by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method and apparatus for constructing a concrete structure. In particular, the invention relates to constructing a concrete structure using pre-cast concrete components.
BACKGROUND OF THE INVENTION
[0003] Natural gas is becoming a greater and greater share of the U.S. energy supply due to advances in hydraulic fracking. Natural gas is generally sent through a pipeline to a terminal, where it is compressed to liquefied natural gas (LNG) before loading it into tanks for transport. This terminal generally includes a platform to support 4-7 compressors, each of which weighs several tons. Due to the increased supply of natural gas, additional terminals are needed to process the supply. However, the terminals are presently constructed by pouring concrete in place for all of the structure, which can take on the order of six months.
SUMMARY OF THE INVENTION
[0004] The present invention broadly comprises a method and apparats for constructing a concrete structure. One embodiment of the invention may be implemented as an apparatus including a pre-cast concrete component and a poured in place concrete surface supported by the pre-cast concrete component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
[0006] FIGS. 1-8 illustrate a process for making a concrete structure according to an exemplary embodiment of the present invention;
[0007] FIG. 9 illustrates several views of one embodiment of a column and a column cap;
[0008] FIGS. 10 and 11 illustrate perspective views of embodiments of the column cap with floor portions stacked thereon;
[0009] FIG. 12 illustrates an top view of the floor sections supported by the column cap;
[0010] FIGS. 13 and 14 show side views of the floor sections supported by the column cap; and
[0011] FIG. 15 shows a perspective cutaway view of the floor sections supported by the column cap; and
[0012] FIG. 16 shows close up side section views of the floor sections supported by the column cap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Reference is presently made in detail to exemplary embodiments of the present subject matter, one or more examples of which are illustrated in or represented by the drawings. Each example is provided by way of explanation of the present subject matter, not limitation of the present subject matter. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present subject matter without departing from the scope or spirit of the present subject matter. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present subject matter covers such modifications and variations as come within the scope of the disclosure and equivalents thereof.
[0014] FIGS. 1-8 show exemplary process steps for constructing a structure 10 in accordance with the present invention. FIG. 8 shows the final structure 10 in one embodiment of the invention. Structure 10 includes columns 20 to support the main surface 50 . Main surface 50 supports the compressors used to compress the LNG. Main surface 50 includes apertures 52 A, 52 B, and 52 C. These apertures allow pipes (not shown) to access the compressors from below main surface 50 . These pipes may link the compressors to each other, as the compression is done in stages. The pipes may also connect to storage tanks to pull off components of the natural gas that liquefy during a particular compression stage.
[0015] In the embodiment shown in FIG. 8 , there are 6 stages to the compression process. Thus, there are 6 sets of apertures 52 A, 52 B, and 52 C. The compression process compresses the natural gas from approximately 5-20 psi to approximately 1,700 psi. Natural gas is mostly methane, but does include other hydrocarbons. Thus, there are other components of the natural gas that liquefy before the methane does. Accordingly, some of the compressors are designed to pull off these other components as the natural gas is compressed. In this regard, the two left-most compressors on main surface 50 need three apertures to provide the piping necessary for their compression stage, while the other four compressors only need two apertures. However, any number of stages and access apertures are within the scope of the invention.
[0016] FIG. 1 shows that the first step includes placing columns 20 . Column caps 30 are then placed on the columns in FIG. 2 . FIG. 9 shows column 20 and column cap 30 in greater detail. FIG. 3 shows that side portions 40 and floor portions 42 are then placed on the column caps 20 . All of these components are pre-cast concrete components, so this process can be done relatively quickly.
[0017] FIG. 4 shows that the side portions 40 and floor portions 42 are assembled for the first third of the structure. Floor portions 42 are designed to include the apertures 52 A, 52 B, and 52 C. As shown in FIG. 5 , concrete may now be poured to create the main surface 50 for the first third of the structure 10 . These pours may be done incrementally, for example breaking each third into 5 pours as shown in FIG. 1-8 . This allows workers to begin constructing the middle third of the structure, as shown in FIG. 5 .
[0018] FIGS. 6 and 7 show the middle and final third of structure 10 being constructed in a similar manner as the first third. Finally, FIG. 8 shows the completed structure.
[0019] Again, as most of the components are pre-cast components, construction can be completed much faster than a structure made of poured in place concrete. The present invention minimizes the used of poured in place concrete, allowing dramatic time savings over the present construction techniques.
[0020] FIG. 9-16 provide greater detail of the pre-cast components 20 , 30 , 40 and 42 . Columns 20 may have steel reinforcement members 22 , as shown in FIG. 13 . Column caps 30 may also have steel reinforcement members 36 , also shown in FIG. 13 . Column caps also include support member 32 and alignment projection 34 . Support member 32 supports the floor portions 40 that are stacked on the column caps 30 . Alignment projections 34 allow the floor portions 40 to be locked into place on the column cap 30 . FIG. 15 shows a perspective view of the floor portions 40 supported by support member 32 and aligned by alignment projections 34 .
[0021] Floor portions 40 may also include steel reinforcement member 44 , as shown in FIG. 15 . Floor portions 40 are locked in place on the column caps by the alignment projections, and may also be linked to each other. Once main surface 50 is cast over the floor portions 44 , all of the components are locked together by main surface 50 .
[0022] The compressors used to compress the natural gas cause a reciprocating load on the supporting structure, which requires a support with isotropic load-bearing properties. As pre-cast components typically are not isotropic, pre-cast components have not been used to support these types of compressors before. In this regard, typical pre-cast components can support 4-5 times the load in a primary direction as opposed to the load that can be borne in secondary directions. For example, pre-cast bridge components typically can support 4-5 times as much load in the traffic direction as compared to the transverse direction. In contrast, the disclosed composite structure can support approximately the same load in all directions. Thus, the present inventors have combined reinforced pre-cast components with a partial poured in place surface to create a composite structure that has the isotropic properties to support the compressors, while being capable of being constructed using much less time and labor than conventional poured in place structures.
[0023] The present written description uses examples to disclose the present subject matter, including the best mode, and also to enable any person skilled in the art to practice the present subject matter, including making and using any devices or systems and performing any incorporated and/or associated methods. While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. | The present invention broadly comprises a method and apparatus for constructing a concrete structure, where one embodiment of apparatus includes a pre-cast concrete component and a poured in place concrete surface supported by the pre-cast concrete component. | 4 |
FIELD OF THE INVENTION
The present invention relates to a two-strand cable window regulator. In particular, the window regulator is specifically designed for control of spherically curved windows of motor vehicle door panels and ensures exact conformity with a predefined lowering/raising path with extremely different radii of curvature of the window located at the two guide rails of the door panel.
BACKGROUND OF THE INVENTION
It is customary to operate spherically curved windows in motor vehicles with hand window regulators, whereby the windows slide in side rails within the vehicle door which reach almost to the bottom of the door. These side rails are necessary to be able to eliminate the forces developing perpendicular to the plane of the window. However, the side rail in the lock region of the door often causes space problems, in particular when the door design is particularly narrow. Consequently, a part of the side rail is often manufactured as an additional and separate part and is installed after assembly of the lock, which increases assembly expense.
In addition, the use of one-strand cable window regulators known in the art often is impractical for the raising and lowering of large, spherically shaped windows, since tipping of the window caused by an inadequate supporting base very often cannot be avoided.
Conventional two-strand cable window regulators are suited to reliably guiding the window in the so-called Y-direction (i.e., at right angle to the plane of the window) and to avoid tipping of the window, but the typical parallel lowering does not correspond to the requirements of the different lowering distances at the locations of each of the two respective guide rails caused by the spherical curvature of the window. Consequently, the window inevitably tips out of its planned tracking path, which may additionally result in jamming.
German patent publication DE-C1 36 15 578 discloses a cable window regulator which presents a combination of two one-strand window regulators whereby each of the two endless loops of cable is guided by a separate cable drum. A single, common drive gear transfers the driving power to both cable drums. The purpose of the design is to avoid alternating bending of each cable and, thus, to improve life of the cable.
Therefore, there is a need to develop a two-strand cable window regulator for motor vehicles which ensures exact lowering of a spherically curved window on a planned lowering path with the use of a simple and economical design. The window regulator should have a low space requirement and ensure good accessibility in the lock region.
SUMMARY OF INVENTION
The present invention is a two-strand window regulator for spherically curved windows, having two guide rails with respective carriers, of which at least one guide rail defines a carrier travel distance which is not equal to a corresponding window travel distance along the window's raising/lowering path. In the case that the guide rail is in the region of the smaller radius of curvature of the spherically curved window, it results in a shortening of the window travel distance. Alternatively, if the guide rail is in the region of the larger radius of curvature of the window, it results in a lengthening of the window travel distance.
The present invention controls the raising/lowering of spherically curved windows and ensures conformity with a predefined path with extremely different radii of curvature of the window located at the two guide rails. This may be accomplished by the following three secondary principles.
First, the guide rail in the region of the smaller radius of the spherical curvature of the window (usually near the A-pillar, or the front hinge pillar region of the door) is disposed at a slant compared to the other guide rail at the location of the larger radius of the window curvature in the displacement plane of the window. The slant is selected such that a carrier during its travel along the guide rail, between its upper and its lower stop position, causes a desired, reduced travel distance of the window along its raising/lowering path.
In order to compensate for the different distances between the carrier and the window bracket at different window positions, some method of compensation acting at a right angle to the lowering path between the carrier and the window bracket (window mounting) is necessary. For example, the compensation can be provided by a compensating rail which is movably connected to the carrier and to the window bracket. The sliding joint of this compensating rail can be disposed either on the carrier or on the window bracket. In addition, it is also possible to provide the compensating movement by means of an elongated slot in the window and a sliding element of the carrier which engages therein.
In a second embodiment, the guide rail in the region of the smaller radius of curvature of the spherical window is curved in the lowering plane at right angles to the lowering path such that a compensating arm linked to the carrier pointing into the interior of the radius of curvature effects the desired curvature of the travel in comparison to the other guide rail. In this case, the compensating arm is connected with the window bracket by means of a rotatable sliding joint. To change the relationship between the displacement distance of the carrier and of the guide rail and the actual travel accomplished, the degree of curvature of the guide rail and/or the lever length of the compensating arm may be appropriately adapted.
Finally, the two guide rails can be disposed on opposite sides of the window, as opposed to prior devices wherein the guide rails were disposed on the same sides of the window. That is, one guide rail is in the region of the smaller radius of curvature of the spherical window in the external space between the window and the exterior panel of the door, and the second guide rail is in the internal space between the window and the interior trim panel of the door. In this embodiment, the radius of the outer guide rail adapted to the window curvature is larger than the radius of curvature of the window, and the radius of the inner guide rail is smaller than the radius of curvature of the window at its corresponding location. An adaptation of the travel distance of the two guide rails to the given requirements of an application may occur by means of modification of the distance of the window glass from the guide path of the guide rail by the use of a lever. Thus, appropriate lever length increases to reduce the travel of the window along the outer guide rail, while increasing the lever length on the inner guide rail results in increasing the travel distance of the window.
Each embodiment disclosed has the distinct advantage that the parallel window raising/lowering characteristic of two-strand cable window regulators can be adapted with simple means to the specific needs of a spherically curved window. Despite equally long displacement paths of the carrier on the two guide rails, the window is moved with different travel distances in the region of the two guide rails.
A final embodiment of the present invention which can be used for displacement of a spherically curved window along two guide rails consists in the use of two separate cables stretched along two distinct guide rails to which respective separate electric motor drives are allocated. The electric motor drives are controlled by a common electronic control unit, which allows the window to be driven in different desired travel distance relationships, in particular through the use of position detection by the control unit.
Importantly, assembly space is gained by elimination of the crossed cable loops. In addition, adaptation to the different window and door panel characteristics of various vehicles is handled largely by software in the electronic control unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in detail referring to exemplary embodiments and the figures presented where:
FIG. 1 is a schematic representation of a two-strand cable window regulator with the guide rail on the hinge pillar side disposed at a slant;
FIG. 1a is a detail of FIG. 1 displaying a compensation rail attached to a window bracket guided on a carrier;
FIG. 2 is a schematic representation of a two-strand cable window regulator with a curved guide rail on the hinge pillar side;
FIG. 2a is a detail of FIG. 2 displaying a carrier with compensating arm attached to a window bracket;
FIG. 3 is a schematic representation of a two-strand cable window regulator with an external guide rail on the hinge pillar side and an internal guide rail on the center pillar side;
FIG. 3a is a schematic representation of FIG. 3 of a longitudinal section through the vehicle door of FIG. 3 along line 3a--3a in the region of the guide rail on the hinge pillar side;
FIG. 3b is a schematic representation FIG. 3 of a longitudinal section through the vehicle door along line 3b--3b in the region of the guide rail on the center pillar side;
FIG. 3c is a schematic representation of FIG. 3 of a cross-section of the vehicle door along line 3c--3c; and
FIG. 4 is a schematic representation of a cable window regulator with two separate cables and respective separate motor drives.
DETAILED DESCRIPTION
The present invention is used in applications in which the advantages of a two-strand cable window regulator coupled with a nonparallel raising/lowering of a window are necessary. An example of such an application is a window which has a pronounced but nonuniform spherical curvature. With the use of a two-strand cable window regulator whose guide rails are disposed in regions of different radius of window curvature, it is necessary to drive the window in the location of the two guide rails with respective different travel distances. In particular, the large front windows between the hinge pillar (i.e. A-pillar) and the center pillar (i.e. B-pillar) of a motor vehicle often present such requirements. However, in principle, the rear windows guided between the center pillar and the lock pillar can also be moved with the window regulators described herein.
The present invention provides various embodiments which achieve the object of the invention. As to which of the following technical means for shortening the travel distance along one guide rail compared to the other guide rail should be used in each application, depends on the concrete conditions of the individual case.
FIG. 1 schematically depicts a two-strand cable window regulator whose guide rail 1A on the hinge pillar side (guide rail in the region of the smaller radius of curvature of the window) is disposed at an angle α relative to the other guide rail 1B on the center pillar side. For clarification of the structural design, both the angle of slant α and the length 3A of a compensating rail 3 dependent thereon is depicted greatly exaggerated.
Moreover, FIG. 1 depicts the carriers 10A, 10B, which are respectively connected to the window by window brackets 4A, 4B, guided on the guide rails 1A, 1B in their corresponding top and bottom stop positions. The compensating rail 3, in the form of a longitudinally grooved box section which is shiftably guided on a fitting shaped part of the carrier 10A in the X-direction and which is at right angles to the raising/lowering path of window 7, is also shown in its top and bottom stop positions. In FIG. 1, the top stop position (i.e., when the window is closed) of each carrier 10A, 10B, each window bracket 4A, 4B, and the compensating rail 3 is represented with solid lines, and the bottom stop position (i.e., when window is open) of each carrier 10A, 10B, each window bracket 4A, 4B, and the compensating rail 3 is depicted as a phantom representation having broken lines with reference numerals corresponding to the top stop position. These solid and broken line representations are utilized in each of the figures to respectively distinguish between the corresponding top and bottom stop positions of each element having a top and bottom stop position.
Referring to FIG. 1a, the window bracket 4A is executed as a clamping element, between whose jaws the window 7 is clamped. Screw connection 30 serves to generate the clamping force to fasten the window to the compensating rail 3. As seen in FIG. 1, the other carrier 10B is directly connected with the window bracket 4B.
Both guide rails 1A, 1B are the same length and have on their respective ends guide pulleys 50, 51, 52, 53 by means of which an endless cable loop 5 is guided. The carriers 10A, 10B are in fixed connection with the cable loop 5 in order to be able to absorb the regulating force generated by a window crank or other type of drive 6.
Upon operation of the drive, the carriers 10A, 10B are shifted on the guide rails 1A, 1B by the same distance. However, because of the slant of the guide rail 1A by the angle α, the maximum travel distance of the window in this region of guide rail 1A is shortened and is represented as follows:
travel distance 2A=travel distance 2B×cos α
whereby the travel distance 2B of the window in the region of the guide rail 1B running parallel to the raising/lowering path of the window 7 corresponds exactly to the displacement distance of the carrier 10A on the slanted guide rail 1A.
During the raising or the lowering of the window 7, the distance between the window bracket 4A and the carrier 10A changes continuously. The necessary compensation occurs by means of a sliding joint connection between the carrier 10A and the compensating rail 3. Of course, differently designed sliding joint connections can be used. For example, the window bracket 4A is mounted shiftably on the compensating rail 3 or a sliding joint connection or is designed which includes an elongated slot provided in the window 7.
In a typical embodiment, the compensating rail 3 is at least the length of a short side of a parallelogram which is formed by a pair of parallel sides formed by the top and bottom positions of the carrier 10A running parallel to the raising/lowering path and by a second pair of parallel sides formed by carrier 10A at its top and bottom positions perpendicular, at a right angle, to the raising/lowering path.
FIG. 2 schematically depicts an additional embodiment of the invention of a two-strand cable window regulator using endless cable loop 5, which is guided by means of cable pulleys 50, 51, 52, 53 and is connected with carriers 10A' and 10B'. Whereas carrier 10B' rests movably on the straight guide rail 1B' running parallel to the raising/lowering direction and bears a window bracket 4B' for mounting on the bottom edge of the window 7, the other carrier 10A' is disposed on a guide rail 1A' curved in the raising/lowering plane. Guide rail 1A' is located in the region of the smaller radius of curvature of the window and effects a shortening of the travel distance of the window compared to the other guide rail 1B', which is of the same length as guide rail 1A'.
FIG. 2a depicts a detail of FIG. 2. According to FIG. 2a, a compensating arm 3' is connected at a right angle to the carrier 10A' and has an elongated slot 310' running in the same direction. Through the elongated slot 310', a screw connection 30' passes to mount the compensation arm on the window 7 bracket 4A'. With the cylindrical shaft 300' of the screw connection 30', the elongated slot 310' forms a rotatable sliding joint to compensate for the different angular positions of the carrier 10A' and for the distance between the carrier 10A' and the window bracket 4A', which varies during window operation.
If the window 7 travels between its top and bottom stop positions, the two carriers 10A', 10B' both cover an equally long path; however, the travel distance 2A' of the window is reduced compared to the travel distance 2B' of the straight guide rail 1B'. The shortening of the travel distance is greater the smaller the radius of curvature R' of the guide rail 1A' (i.e., the sharper the curve of guide rail 1A').
The compensating arm 3' pointing in the direction of the center of the radius of curvature of the guide rail 1A' guides the window bracket 4A' apparently in an arc whose radius is smaller than the radius R' of the guide rail 1A'. Thus, it is possible to affect the amount of shortening of the travel distance of the window through variation of the distance of the window bracket 4A' from the guide rail 1A'.
On the other hand, it is also possible to use a straight shaped guide rail on the hinge pillar side and to equip a curved guide rail on the center pillar side with a carrier such that its compensating arm points radially outward, i.e., away from the center of the circle of curvature. Thus, a travel distance increase is caused on this guide rail. The travel distance on the guide rail on the hinge pillar side in the region of the smaller radius of curvature of the window 7 thus remains relatively smaller. Advantages of the invention can be accomplished equally well with both embodiments.
FIG. 3 through 3c depict a further embodiment of the invention. Here again, there is a two-strand cable window regulator consisting of the customary components including guide rails 1A", 1B", carriers 10A", 10B" with window brackets 4A", 4B", guide pulleys 50, 51, 52, 53 to guide the cable loop 5 and drive 6. Spherically curved window 7 has as depicted in FIG. 3a region of smaller radium of curvature R A , as depicted in FIG. 3b region of larger radius of curvature R B , and as depicted in FIG. 3c transitional radii of curvature therebetween. However, a novel and unobvious feature consists in that the guide rail 1A" on the hinge pillar side is disposed in the region of the smaller radius of curvature R A of the spherical window 7 between the exterior panel 8 of the door and the window 7, whereas the other guide rail 1B" on the center pillar side is mounted in the region of the larger radius of curvature R B of window 7 between the interior panel 9 of the door and the window 7. Here, the radius of curvature R.sub. " of the outer guide rail 1A" on the hinge pillar side is greater than the radius of curvature R A of the window 7; on the contrary, the radius of curvature R b " of the inner guide rail 1B" on the center pillar side is greater than the radius of curvature R B of the window 7 in this region.
Between the carriers 10A", 10B" and the window brackets 4A", 4B" there is a distance defined by respective lengths 3A", 3B" of connection levers 3", 3"'. With increasing lever lengths 3A", 3B", travel distances 2A", 2B" deviating more greatly from the displacement distances of the carriers 10A", 10B" are generated. Thus, increases in the length of the inward pointing connection lever 3" result in a travel distance shortening on the outer guide rail 1A" on the hinge pillar side; in contrast, increases in the length of the outward pointing connection lever 3"' cause a travel distance increase on the inner guide rail 1B" on the center pillar side. By harmonizing the structural conditions of the window attachment of the two guide rails 1A", 1B", the respective travel distances 2A", 2B" are defined.
At this point, it should also be indicated that the embodiment of the invention just described requires a Bowden window regulator such that the cable 5 can be guided below the bottom edge of the window, even when the window 7 is in its lowest position. Bowden window regulators, which are well known in the art, use a cable surrounded by a sheath or casing wherein the end points of the sheath or casing are in space. In this way, the cable can be moved within the sheath or casing when the window crank or other type of drive 6 is activated.
An alternate embodiment, according to the schematic representation of FIG. 4, also accomplishes advantages of the invention wherein travel distances on two guide rails of a cable window regulator are not of the same size.
The regulating system consists of two drives 6A, 6B, which are attached to the window 7 and which bear carriers 10A"', 10B"', which are form-fittingly connected with the cross section of the guide rails 1A"', 1B"'. Separate cables 5A, 5B are stretched between the ends of the guide rails 1A"', 1B"' respectively by clamping points 500, 510, and 520, 530. They loop around the cable drums 60A, 60B, which can be made to rotate by each corresponding drive. Thus, drives 6A, 6B, connected with the window 7, cause the window to move upward or downward.
Since both drives 6A, 6B are controlled by a common electronic control unit 70, different travel distances or speeds of travel can be covered on the two guide rails 1A"', 1B"'. In conjunction with position detection which occurs within the electronic control unit, complex cable cycles are implemented.
The disclosure of attached German patent application, number P 44 27 989.2, filed on Aug. 8, 1994 is incorporated fully herein by reference. Priority of this German application is claimed.
Having now described the invention in detail as required by the patent statute, those skilled in the art will recognize modifications and substitutions to the embodiments disclosed herein. Such modifications and substitutions are encompassed within the present invention as defined in the following claims. | The invention concerns a two-strand cable window regulator for motor vehicles having two guide rails which is specifically designed to control spherically curved windows. The invention ensures exact conformity with a predefined raising/lowering path with extremely different radii of curvature of the window at the locations of the two guide rails.
The present invention ensures exact conformity by modifying the travel distance of the window near at least one guide rail such that the travel distance of the window is either larger or smaller than the distance traveled by the respective carrier connected to the guide rail. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates to a system debugging device for debugging a system in which a plurality of bus masters mounted on a large-scale integrated circuit (LSI) share an internal bus.
[0003] 2. Description of Related Art
[0004] FIG. 5 is a diagram showing an example of a technique for debugging a system, in which a central processing unit 32 (CPU) is mounted on an LSI 30 (hereinafter referred to as CPU-containing system). The CPU-containing system in FIG. 5 includes bus masters 34 , such as a CPU, a direct memory access (DMA) controller 36 , and other bus masters; and bus slaves 38 , such as an external memory interface (I/F), an internal memory, and other bus slaves. All of the bus masters 34 and bus slaves 38 are mutually connected via an internal bus 33 , and this CPU-containing system is connected via the external memory I/F to an external memory 31 .
[0005] FIG. 6 is a diagram showing an example of the inner structure of the CPU-containing system in FIG. 5 . For ease of explanation, the CPU 32 and the DMA controller 36 are shown as bus masters, while Slave 1 , Slave 2 , and Slave 3 are shown as bus slaves.
[0006] Address signals, bus control signals, and data signals outputted from the CPU 32 and the DMA controller 36 are selectively outputted from a multiplexer MUX 1 , according to master selection information outputted from a bus arbiter 12 arbitrating bus ownership, and are inputted into Slave 1 , Slave 2 , and Slave 3 , respectively. Address signals outputted from the multiplexer MUX 1 are also inputted into an address decoder 14 selecting bus slaves. Data signals outputted from Slave 1 , Slave 2 , and Slave 3 are selectively outputted from a multiplexer MUX 2 , according to slave selection information outputted from the address decoder 14 , and are inputted into the CPU 32 and the DMA controller 36 .
[0007] In the CPU-containing system shown in FIG. 6 , in order for the CPU 32 and the DMA controller 36 , which are bus masters, to use the internal bus, the CPU 32 and the DMA controller 36 send bus request signals (not shown) to the bus arbiter 12 .
[0008] When the bus request signals are received, the bus arbiter 12 selects, according to the priority of bus ownership (that is, a right to use the internal bus) at that time, a bus master having the highest priority among those that have sent bus request signals. Then, the bus arbiter 12 sends grant signals (not shown) to the selected bus master, so as to indicate that the bus ownership is granted. At the same time, the bus arbiter 12 sends master selection information for specifying the selected bus master to the multiplexer MUX 1 .
[0009] Address signals, bus control signals, and data signals outputted from the bus master that has received the grant signals are then selectively outputted from the multiplexer MUX 1 according to the master selection information outputted from the bus arbiter 12 .
[0010] The address decoder 14 decodes the address signals outputted from the multiplexer MUX 1 to generate slave selection signals (not shown). The slave selection signals are signals for selecting a bus slave specified by the address signals and are sent to Slave 1 , Slave 2 , and Slave 3 , respectively. At the same time, the address decoder 14 sends slave selection information for specifying the selected bus slave to the multiplexer MUX 2 .
[0011] Slave 1 , Slave 2 , and Slave 3 receive the slave selection signals. When one of the slaves is selected, data signals are written into the selected slave according to the address signals and bus control signals (write signals) outputted from the multiplexer MUX 1 . Data signals read from the selected slave according to the address signals and bus control signals (read signals) are selectively outputted from the multiplexer MUX 2 according to the slave selection information outputted from the address decoder 14 .
[0012] Then, data signals outputted from the multiplexer MUX 2 are received by the bus master that received the above-described grant signals.
[0013] When the above-described CPU-containing system is compliant with the joint test action group (JTAG) standard, debugging of the system is normally performed, as shown in FIG. 5 , by connecting the CPU 32 to an in-circuit emulator (ICE) via a debugging I/F, and further connecting the ICE to a personal computer (PC), thereby monitoring the operation of the CPU 32 , while controlling it, using a debugger (software program for debugging) running on the PC.
[0014] Normally, information on a stop address, which is called a breakpoint, from the debugger running on the PC is placed in user software to be debugged. When the CPU reaches the address of the breakpoint, the ICE not only stops the operation of the CPU, but also reads, if necessary, the internal states of registers and memories that are connected to an internal register and internal bus of the CPU into the PC. An operator responsible for debugging proceeds with the debugging process based on this information while monitoring the hardware status.
[0015] However, in a known debugging process for a system in which a plurality of bus masters including a CPU are mounted on an LSI, a transfer of bus ownership from the CPU to other bus masters causes debugging to stop, because the CPU cannot monitor the operation of other bus masters in this case. Specifically, the CPU cannot obtain any information, for example, as to whether or not the bus ownership is transferred to other bus masters, and if transferred, as to the size and duration of data transfer, from which bus master to which slave.
[0016] Conventional techniques related to the present invention are disclosed, for example, in Japanese Unexamined Patent Application Publication No. 63-167940 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 5-14451 (Patent Document 2).
[0017] Patent Document 1 is concerned with a multiprogramming-oriented CPU responsible for processing of an operating system to achieve multiprogramming. Patent Document 1 discloses means for outputting information concerning a multiprogramming system to an external data bus of the CPU, during execution of a system call instruction, and showing to devices outside the CPU that the information has been outputted to the external data bus.
[0018] Patent Document 2 is concerned with a line monitoring method for a data communication system that includes a line control unit performing alternate communication with external data communication devices via a transmission line and a human-machine interface unit performing input and output operations for the entire system. Patent Document 2 discloses that, in the line monitoring method, send data and receive data on an output line and an input line, respectively, in the line control unit are collected at an input/output section of the line independently of a data transmission control circuit for online operation. Also, Patent Document 2 teaches that the collected send/receive data is stored in the data communication system, and the stored send/receive data is displayed according to instructions from the human-machine interface unit.
SUMMARY OF THE INVENTION
[0019] An exemplary object of the present invention is to solve the above-described problems in the conventional techniques and provide a system debugging device and a system debugging method where, even if bus ownership is transferred from a CPU to other bus masters, the operation of other bus masters can be monitored so as to achieve efficient system debugging.
[0020] To achieve the object described above, various exemplary implementations of the present invention provide for a system debugging device for debugging a system in which a plurality of bus masters mounted on an LSI share a bus, the device including first means for recording a variety of information including master selection information for specifying a bus master to which a right to use the bus is granted, and slave selection information for selecting a bus slave specified according to address signals outputted from the bus master; and second means for reading, via the bus, the variety of information recorded in the first means.
[0021] Moreover, various exemplary implementations of the present invention provide for a system debugging device for debugging a system in which a plurality of bus masters mounted on an LSI share a bus, the device including first means for recording a variety of information, including master selection information for specifying a bus master to which a right to use the bus is granted and slave selection information for selecting a bus slave specified according to address signals outputted from the bus master; and second means for outputting, via a JTAG-compliant scan chain, the variety of information recorded in the first means.
[0022] Preferably, the above-described exemplary system debugging device may further include third means for setting information for specifying start and stop of recording of the variety of information by the first means; and fourth means for controlling, based on the information set in the third means, start and stop of recording of the variety of information by the first means.
[0023] According to various exemplary implementations of the system debugging device of the present invention, it can be seen whether or not bus ownership is transferred to bus masters other than the CPU, during program execution, for example, during the period from the initial state to the next breakpoint, or during the period from one breakpoint to the next breakpoint; and which bus master accesses which slave. Moreover, the detailed status of bus occupation in a certain section can be seen by recording information, such as the amount, duration, and style of data transfer, as necessary. Therefore, the exemplary system can keep track of bus priority and the amount of data transfer in each bus master in real time, thereby reliably determining whether or not hardware and software are properly designed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagram showing an exemplary embodiment of a CPU-containing system to which a system debugging device of the present invention is applied;
[0025] FIG. 2 is a diagram showing a first exemplary embodiment of the system debugging device in FIG. 1 ;
[0026] FIG. 3 is a diagram showing a second exemplary embodiment of the system debugging device in FIG. 1 ;
[0027] FIG. 4 is a diagram showing a third exemplary embodiment of the system debugging device in FIG. 1 ;
[0028] FIG. 5 is a diagram showing an example of a conventional technique for debugging a CPU-containing system; and
[0029] FIG. 6 is a diagram showing an example of the CPU-containing system in FIG. 5 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] A system debugging device of the present invention will now be described in detail based on preferred embodiments shown in the accompanying drawings.
[0031] FIG. 1 is a diagram showing an exemplary embodiment of a CPU-containing system to which a system debugging device of the present invention is applied. According to various exemplary implementations, a CPU-containing system 10 in FIG. 1 is formed by applying the present invention to the CPU-containing system shown in FIG. 6 and is further provided with a bus slave, Slave 4 , that is the system debugging device of the present embodiment.
[0032] According to various exemplary implementations, Slave 4 is accessible by bus masters, similarly to Slave 1 , Slave 2 , and Slave 3 . Address signals, bus control signals, and data signals that are outputted from a multiplexer MUX 1 are inputted into Slave 4 . Moreover, according to various exemplary implementations, master selection information outputted from a bus arbiter 12 and slave selection information outputted from an address decoder 14 are also inputted into Slave 4 . Data signals outputted from Slave 4 are inputted into a multiplexer MUX 2 .
[0033] FIG. 2 is a diagram showing a first exemplary embodiment of the system debugging device in FIG. 1 , and shows the inner structure of Slave 4 in FIG. 1 . According to various exemplary implementations, Slave 4 includes a first circuit 16 for storing the master selection information outputted from the bus arbiter 12 , and a second circuit 18 for storing the slave selection information outputted from the address decoder 14 .
[0034] According to various exemplary implementations, the first circuit 16 includes a controller 20 , a control register and bus I/F 22 , and a recording memory or register 24 .
[0035] According to various exemplary implementations, bus control signals are inputted into the controller 20 . A bus address and bus data (write) are inputted into the control register and bus I/F 22 , which outputs bus data (read). The bus address, bus data (write), and bus data (read) correspond respectively to the address signals and data signals that are outputted from the multiplexer MUX 1 shown in FIG. 1 , and the data signals outputted from Slave 4 shown in FIG. 1 .
[0036] According to various exemplary implementations, the control register and bus I/F 22 outputs start and stop instructions, which are inputted into the controller 20 . The controller 20 outputs write control signals, which are inputted into the recording memory or register 24 . Master selection information outputted from a bus arbitration circuit 26 of the bus arbiter 12 is inputted into the recording memory or register 24 . According to various exemplary implementations, the master selection information recorded is outputted from the recording memory or register 24 and inputted into the control register and bus I/F 22 .
[0037] According to various exemplary implementations, the structure of the second circuit 18 is identical to that of the first circuit 16 , except that signals inputted into the recording memory or register 24 are not master selection information, but slave selection information outputted from a decoder 28 of the address decoder 14 . Therefore, the same components are indicated by the same reference numerals and the detailed description of the second circuit 18 will be omitted. The controllers 20 in the respective first circuit 16 and second circuit 18 are connected, and send and receive the controller statuses to and from each other.
[0038] According to various exemplary implementations, the CPU directly sets start and stop instructions, which indicate when to start and stop recording of master selection information and slave selection information, in the control register and bus I/F 22 in each of the first circuit 16 and the second circuit 18 .
[0039] Alternatively, the CPU may set control information in the control register and bus I/F 22 in each of the first circuit 16 and the second circuit 18 so as to provide circuits for generating start and stop instructions based on the control information. According to various exemplary implementations, the control information includes conditions as triggers for starting, such as when an address reaches a certain value, when a certain bus master is selected, when certain data appears on a bus, and after N data items are sent immediately after the completion of a certain cycle. Triggers for stopping are similar to those for starting.
[0040] Start and stop conditions may be determined, for example, by monitoring the states of the bus arbiter 12 and the address decoder 14 . Therefore, the master selection information and the slave selection information can be recorded independently, or can be recorded in conjunction with each other. Moreover, the controllers 20 of the respective first circuit 16 and second circuit 18 can perform recording by monitoring each other's states (controller states), for example, in a synchronous or asynchronous manner.
[0041] According to various exemplary implementations, when one of the controllers 20 receives start and stop instructions from the corresponding control register and bus I/F 22 to start recording, the controller 20 generates write control signals with reference to bus control signals. The bus control signals include clock signals and information, such as the output timing of valid master selection information or slave selection information. The controller 20 refers to the bus control signals to obtain the timing of recording the master selection information or the slave selection information so as to generate write control signals, such as address signals and write signals.
[0042] According to various exemplary implementations, the write control signals from the controller 20 allow the master selection information or the slave selection information to be recorded in the recording memory or register 24 in the first circuit 16 or the second circuit 18 .
[0043] Then, when start and stop instructions from the control register and bus I/F 22 to stop recording are received, the controller 20 terminates the generation of write control signals, thereby completing the recording of information.
[0044] According to various exemplary implementations, after the completion of information recording, the CPU reads, via the control register and bus I/F 22 , the information recorded in the recording memory or register 24 and sends the information, via the ICE, to the debugger on the PC. Thus, with reference to the master selection information and the slave selection information, an operator responsible for debugging can keep track of the situation, for example, whether or not the bus ownership is transferred from the CPU to other bus masters, which bus master obtains the bus ownership, and which slave is selected by the bus master.
[0045] Although the system debugging device of the present invention, in the embodiment shown in FIG. 1 , is installed in the form of Slave 4 on an LSI, the system debugging device of the present invention is not limited to this and may take other forms that can read information stored in the recording memory or register 24 . For example, the system debugging device of the present invention may be incorporated in the bus arbiter 12 , the address decoder 14 , or other bus slaves. Moreover, the system debugging device of the present invention is also applicable to a system in which the functions of the bus arbiter 12 are installed in the CPU.
[0046] According to various exemplary implementations, information may be recorded consistently up to a predetermined amount or for a predetermined period of time, instead of using start and stop instructions.
[0047] According to various exemplary implementations, a controller 20 may be provided, for example, with a unit for counting the number of clock signals included in bus control signals, and a unit for counting the amount of data transfer, thereby generating and recording information, such as the time required for data transfer and the amount of data transfer. Furthermore, a variety of information including the style of data transfer (such as burst type and data type) can be recorded. The performance of debugging can be improved by recording and referring to such a variety of information.
[0048] As shown in FIG. 3 , the controller 20 , the control register and bus I/F 22 , and the recording memory or register 24 in each of the first circuit 16 and the second circuit 18 , which are shown in FIG. 2 , may be integrated and shared. In this case, master selection information, slave selection information, and the above-described variety of information, when needed, are recorded in the recording memory or register 24 . A reduction in circuit size can thus be achieved in the system debugging device shown in FIG. 3 .
[0049] When the CPU-containing system or the CPU is JTAG compliant, the JTAG standard is also applicable to the system debugging device, as indicated by the dotted lines in FIG. 4 . In this case, JTAG scan chains that operate under the same protocol as that of the CPU-containing system or the CPU are provided such that setting of control information, reading of recorded information, start and stop control, and the like can be performed without the CPU accessing the system debugging device via the internal bus.
[0050] The above description has been given based on the exemplary system in which a CPU is installed. Debugging can also be efficiently performed through the use of means for reading a variety of stored information to the outside of the chip or by a bus master having this means.
[0051] Although the system debugging device of the present invention has been described in detail, the present invention is not limited to the above-described embodiments, but various improvements and changes may be made without departing from the purpose of the present invention. | A system debugging device in which, even if bus ownership is transferred to other bus masters, the operations of the other bus masters can be monitored such that efficient debugging of a system can be achieved is provided. In a system where a plurality of bus masters mounted on an LSI share a bus, the system debugging device includes a recorder for recording a variety of information including master selection information for specifying a bus master to which a right to use the bus is granted and slave selection information for selecting a bus slave specified according to address signals outputted from the bus master; and a reader for reading, via the bus, the variety of information recorded in the recorder. | 6 |
CROSS REFERENCE TO RELATED PATENT APPLICATION
[0001] The present patent application claims the right of priority under 35 U.S.C. §119 (a)-(d) of German Patent Application No. 10 2006 003 033.8, filed Jan. 20, 2006.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to ballast and to a process for the production of ballast, which has a high stability and long service life, for railway track laying and road construction and dike systems used for example in costal protection. This ballast consists of ballast stones and a polyurethane foam based on a reaction mixture of selected polyisocyanates and selected compounds which contain isocyanate-reactive groups.
[0003] The demand for ballast used in railway track laying and road construction has increased sharply in recent years. One reason for this is certainly the general increase in population mobility and freight traffic. Rail traffic, in particular, comprises an ever-increasing proportion of high-speed trains with a large axle load. The enormous displacement forces they cause are transmitted via the rails to the sleepers and from there to the ballast. The stone formation changes over time and individual ballast stones become distorted, shifted and rounded, so the position of the tracks is changed, which requires cost-intensive and time-consuming repair work that must be carried out at regular intervals.
[0004] Various methods of consolidating ballast with the incorporation of plastics have already been described in the past. See, for example, DD 86201, DE-A 2063727, DE-A 2305536, DE-A 3941142, DE-A 19711437, DE-A 19651755, DE-A 3821963, DE-A 19811838, and JP-A 08157552.
[0005] DE-A 2063727 describes a method of reducing lateral track buckling due to lateral displacement forces. In this case, the binder is sprayed onto the ballast bed in the form of a high-viscosity plastic and the ballast stones are adhesively bonded together at the points of contact. A possible alternative is 2-dimensional adhesive bonding of the ballast stones by injection of the binder in the form of a 2-component synthetic resin.
[0006] A method of raising railway sleepers and road surfaces is described in DE-A 2305536 which requires the introduction of a swelling agent, which then solidifies. The swelling agent is, for example, a multicomponent plastic such as polyurethane foam. The liquid plastic is applied through a hole in the sleeper using a filling probe.
[0007] JP-A 8157552 describes the preparation of polyurethane resins which cure in the presence of moisture and are used to stabilize piles of stones. The polyurethane resins are prepared using aromatic polyisocyanates, monofunctional polyethers and amino-initiated polyethers, and are applied by means of spraying processes.
[0008] A common feature of all the known methods is that they produce ballast which can only be stabilized unselectively with the aid of plastics. Furthermore, in some cases the methods described rely on a relatively complicated application technology.
[0009] The object of the present invention was to provide an improved process for the production of ballast which allows stabilization of the ballast and at the same time ensures a long service life.
[0010] Surprisingly, the object of the invention could be achieved by the process of the present invention as described below.
SUMMARY OF THE INVENTION
[0011] The present invention provides a process for the production of ballast for railway track laying and road construction and dike systems. This process comprises
1) spreading out ballast stones to form ballast, and 2) applying a polyurethane foam forming reaction mixture between the spread ballast stones, wherein the reaction mixture is prepared from:
a) one or more isocyanate compounds selected from the group consisting of (I) one or more polyisocyanates having an NCO group content of 28 to 50 wt. % and (II) one or more NCO prepolymers having an NCO group content of 10 to 48 wt. %, which are prepared from one or more polyisocyanates having an NCO group content of 28 to 50 wt. %, and at least one hydroxyl group containing compound selected from the group consisting of one or more polyetherpolyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100 and one or more alkylenediols having a hydroxyl number of 645 to 1850; and b) a polyol component comprising one or more polyether polyols having a hydroxyl number of 6 to 112 and a functionality of 1.8 to 8; in the presence of c) 0 to 26 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more chain extenders having a hydroxyl number or an amine number of 245 to 1850 and a functionality of 1.8 to 8; d) 0.05 to 5 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more blowing agents; e) 0 to 5 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more catalysts; f) 0 to 50 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more fillers; and g) 0 to 25 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more auxiliary substances and/or additives;
in which the isocyanate index of the reaction mixture ranges from 70 to 130.
DETAILED DESCRIPTION OF THE INVENTION
[0026] As used herein, the term Isocyanate Index is understood as meaning the equivalent ratio of NCO groups to OH groups and NH groups, multiplied by 100. Thus, for example, an isocyanate index of 110 means that there are 1.1 reactive NCO groups from the isocyanate compounds per reactive OH group and/or NH group, or that there are 0.91 reactive OH groups and/or NH groups per reactive NCO group from the isocyanate compounds.
[0027] The suitable components for preparing the polyurethane foams are used in a mixing ratio that allows homogeneous mixing of the components, especially when using high-pressure machines. The use of high-pressure machines also makes it possible to process quick-reacting PUR systems, and hence affords an economic process. In addition, the processing properties of the PUR system can be optimized to requirements by using the raw materials described in greater detail below. Thus, one possible application method is a partial foaming of the ballast using pouring technology. Furthermore, the mechanical properties of the polyurethane foams used can be varied within wide limits. The advantages of the PUR foams used are good compression forces (at 10% compression) (≧10.0 N), good compression hardness (at 10% compression) (≧1.0 kPa) and tensile strengths (≧0.1 MPa) coupled with a low compression set (CS (40%, 25° C., 5 min) ≦0.01%).
[0028] The polyurethane foams of the present invention are preferably prepared in the presence of chain extenders and catalysts. It is preferable here to use catalysts which have primary and/or secondary hydroxyl and/or amino groups. The polyurethanes obtained in this way have an improved emission behavior and, after extraction with solvents (e.g. water), are distinguished by a reduced proportion of mobilizable ingredients. Optionally, the polyurethane foams according to the invention can additionally contain fillers, auxiliary substances and/or additives which are known per se from polyurethane chemistry.
[0029] The present invention also provides ballast consisting of polyurethane foam and ballast stones. In accordance with the invention, the ballast herein is characterized in that the polyurethane foam is located between the ballast stones. The suitable polyurethane foam is prepared from a reaction mixture comprising:
a) one or more isocyanate compounds selected from the group consisting of (I) polyisocyanates having an NCO group content of 28 to 50 wt. %, and (II) NCO prepolymers having an NCO group content of 10 to 48 wt. % and which comprise the reaction product of one or more polyisocyanates having an NCO group content of 28 to 50 wt. %, with a hydroxyl group containing compound selected from the group consisting of one or more polyetherpolyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100 and one or more alkylenediols having a hydroxyl number of 645 to 1850; and b) a polyol component comprising one or more polyetherpolyols having a hydroxyl number of 6 to 112 and a functionality of 1.8 to 8; in the presence of c) 0 to 26 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more chain extenders with a hydroxyl number or amine number of 245 to 1850 and a functionality of 1.8 to 8; d) 0.05 to 5 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more blowing agents; e) 0 to 5 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more catalysts; f) 0 to 50 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more fillers; and g) 0 to 25 wt. %, based on 100% by weight of the sum of reaction components b) through g), of one or more auxiliary substances and/or additives;
wherein the isocyanate index of the reaction mixture ranges from 70 to 130.
[0039] With regard to processing, the reaction mixture for preparation of the polyurethane foam is adjusted so that it can be used with a simple application technology such as, for example, the pouring process. A partial foaming of the ballast can be effected, for example, by specific adjustment of the reactivity of the reaction mixture. Such a partial foaming makes it possible on the one hand, to selectively strengthen the ballast in particularly stressed regions (such as e.g. curves, and load dissipation regions) and on the other hand, allows the uninhibited drainage of liquids such as water. The effect of an excessively slow reaction would be that the reaction mixture drained into the soil or marginal regions of the ballast bed. The effect of an excessively rapid reaction would be that the reaction mixture did not penetrate to a sufficient depth in the layers of bulk material. For example, for a track system with a ballast height of approx. 40 cm, a suitable initiation time for the reaction mixture should range from 1 to 15 seconds, preferably from 1 to 5 seconds, and a suitable solidification time (i.e. curing time) for the reaction mixture should range from 15 to 45 seconds, preferably from 15 to 30 seconds. Although longer solidification times are possible, they are not economical. Thus, longer solidification times are not typically used.
[0040] The polyurethane foams suitable for the present invention should preferably have a compression force (at 10% compression) of at least 10.0 N, a compression hardness (at 10% compression) of at least 1.0 kPa and a tensile strength of at least 0.1 MPa. Furthermore, these polyurethane foams should also preferably have a compression set (CS) (40%, 25° C., 5 min) of at most 0.01% and a good stability to weathering and hydrolysis. The polyurethane foam used should also be distinguished by the having the lowest possible proportion of emissible and mobilizable ingredients.
[0041] Suitable polyisocyanates to be used as component a) herein include (cyclo)aliphatic and/or aromatic polyisocyanates, and preferably toluene diisocyanate, and diisocyanates and/or polyisocyanates of the diphenylmethane series which have an NCO group content of 28 to 50 wt. %. Diisocyanates of the diphenylmethane series includes, for example, mixtures of 4,4′-diisocyanato-diphenylmethane with 2,4′-diisocyanatodiphenylmethane and, optionally, a small proportion of 2,2′-diisocyanatodiphenylmethane, with the mixtures being liquid at room temperature, and, which may optionally be appropriately modified. Other suitable polyisocyanates to be used as component a) include polyisocyanate mixtures of the diphenylmethane series which are liquid at room temperature, and contain not only the isomers mentioned above but also contain their higher homologues, and which are obtainable in a manner known per se by the phosgenation of aniline/formaldehyde condensation products. Modified products of these diisocyanates and/or polyisocyanates which have urethane or carbodiimide groups and/or allophanate or biuret groups are also suitable.
[0042] Suitable NCO prepolymers having an NCO group content of 10 to 48 wt. % are also suitable to be used as component a) herein. These prepolymers are prepared from the above-mentioned polyisocyanates and at least one hydroxyl group containing compound. Suitable hydroxyl group containing compounds are selected from the group consisting of one or more polyether polyols having a hydroxyl number of 6 to 112, one or more polyoxyalkylenediols having a hydroxyl number of 113 to 1100, one or more alkylenediols having a hydroxyl number of 645 to 1850 and mixtures thereof.
[0043] Suitable compounds to be used as component b) include polyhydroxy polyethers which can be prepared in a manner known per se by the polyaddition of alkylene oxides onto suitable polyfimctional starter compounds in the presence of catalysts. The polyhydroxy polyethers are preferably prepared from a starter compound having an average of 2 to 8 active hydrogen atoms, and one or more alkylene oxides. Preferred starter compounds include molecules with two to eight hydroxyl groups per molecule, such as water, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol 1,4-butanediol, 1,6-hexanediol, triethanolamine, glycerol, trimethylolpropane, pentaerythritol, sorbitol and sucrose. The starter compounds can be used either alone or in a mixture with other suitable starter compounds. These polyols used as component b) are typically prepared from one or more alkylene oxides, the alkylene oxides used preferably being oxirane, methyloxirane and ethyloxirane. The alkylene oxides can also be used either alone or in a mixture with other alkylene oxides. When used in a mixture, the alkylene oxides can be reacted randomly and/or in blocks. Higher-molecular weight polyhydroxy polyethers in which high-molecular polyadducts/polycondensation products or polymers are in finely dispersed, dissolved or grafted form are also suitable. Such modified polyhydroxyl compounds are obtained, for example, by allowing polyaddition reactions (e.g. reactions between polyisocyanates and amino-functional compounds) or polycondensation reactions (e.g. between formaldehyde and phenols and/or amines) to proceed in situ in the polyhydroxy polyether compounds used as component b) which contain hydroxyl groups (as described in, for example, DE-AS 1 168 075, the disclosure of which is hereby incorporated by reference). Polyhydroxyl compounds modified by vinyl polymers, such as those obtained e.g. by the polymerization of styrene and/or acrylonitrile in the presence of polyether polyols (as described in, for example, U.S. Pat. No. 3,383,351, the disclosure of which is hereby incorporated by reference), are also suitable as polyol component b) for the process according to the invention. Other suitable representatives of hydroxyl group containing compounds to be used component b) herein are described in, for example, Kunststoff-Handbuch, volume VII “Polyurethane”, 3rd edition, Carl Hanser Verlag, Munich/Vienna, 1993, pages 57-67 and pages 88-90.
[0044] In accordance with the present invention, component b) preferably comprises one or more polyhydroxy polyethers which have a hydroxyl number of 6 to 112, preferably of 21 to 56, and a functionality of 1.8 to 8, preferably of 1.8 to 6.
[0045] Suitable chain extenders to be used as component c) in accordance with the present invention include those having a mean hydroxyl number or a mean amine number of 245 to 1850 and a functionality of 1.8 to 8, preferably of 1.8 to 3. Examples which may be mentioned here include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, triethanolamine, glycerol, trimethylolpropane and other short-chain alkoxylation products. Component c) is preferably used in amounts ranging from 0 to 26 wt. %, based on 100% by weight of the sum of reaction components b) through g). It is particularly preferable to use ethylene glycol, 1,4-butanediol, the propoxylation product of trimethylolpropane (having an OH number of 550) and/or a mixture of triethanolamine and diisopropanolamine (having an OH number of 1160) as chain extenders in the present invention.
[0046] Suitable blowing agents to be used as component d) in accordance with the present invention include both physical blowing agents and water. Preferable physical blowing agents d) are 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1,2,3,3,3,-heptafluoropropane (HFC-227ea), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc), n-pentane, i-pentane, i-hexane or mixtures thereof. Water is most preferably used as component d). The blowing agents can be used by themselves or in combination with each other and are present in amounts ranging from 0.05 to 5 wt. %, and more preferably in amounts ranging from 0.3 to 3.5 wt. %, based on 100% by weight of the sum of reaction components b) through g).
[0047] The intrinsically slow reaction between isocyanate groups and hydroxyl groups can be accelerated by the addition of e) one or more catalysts. Particularly suitable catalysts e) include tertiary amines of the type known per se, such as, for example, triethylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, N-cocomorpholine, N,N,N′,N′-tetramethylethylenediamine, 1,4-diaza-bicyclo[2.2.2]octane, N-methyl-N′-dimethylaminoethylpiperazine, N,N-dimethyl-cyclohexylamine, N,N,N′,N′-tetramethyl-1,3-butanediamine, N,N-dimethyl-imidazo-β-phenylethylamine, 1,2-dimethylimidazole, bis(2-dimethylaminoethyl)ether or 2-methylimidazole. It is also possible to use organic metal catalysts such as organic bismuth catalysts such as, for example, bismuth(III)neodecanoate, or organic tin catalysts such as, for example, tin(II) salts of carboxylic acids, such as tin(II)acetate, tin(II)octanoate, tin(II)ethylhexanoate and tin(II)laurate, and the dialkyltin salts of carboxylic acids, e.g. dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and/or dioctyltin diacetate, by themselves, or in combination with one or more of the tertiary amine catalysts. It is preferable to use catalysts having primary and/or secondary hydroxyl and/or amino groups, suitable catalysts being both incorporable amines and incorporable organic metal catalysts of the type known per se, e.g. N-(3-dimethylaminopropyl)-N,N-diisopropanolamine, N,N,N′-trimethyl-N′-hydroxyethylbisaminoethyl ether, tetramethyl-dipropylenetriamine, 3-(dimethylamino)propylurea and tin ricinoleate. The catalysts can be used by themselves or in combination with each other. It is preferable to use from 0 to 5.0 wt. %, and more preferable to use from 0.5 to 5.0 wt. %, of catalyst or catalyst combination, based on 100% by weight of the sum of reaction components b) through g). Other representatives of catalysts and particulars of the mode of action of the catalysts are described in Kunststoff-Handbuch, volume VII “Polyurethane”, 3rd edition, Carl Hanser Verlag, Munich/Vienna, 1993, pages 104-110.
[0048] Suitable fillers to be used as component f) which are optionally used concomitantly can be both inorganic fillers and organic fillers. Examples of inorganic fillers which may be mentioned are silicate minerals such as sheet silicates, metal oxides such as iron oxides, pyrogenic metal oxides such as aerosils, metal salts such as baryte, inorganic pigments such as cadmium sulfide and zinc sulfide, glass, glass microspheres, hollow glass microspheres, etc. It is possible to use natural and synthetic fibrous minerals such as wollastonite and glass fibers of different length, which can optionally be sized. Examples of organic fillers which may be mentioned are crystalline paraffins or fats, and powders based on polystyrene, polyvinyl chloride, urea/formaldehyde compounds and/or polyhydrazodicarbonamides (which can be prepared, for example, from hydrazine and toluene diisocyanate). Hollow microspheres of organic origin, or cork, can also be used. The organic fillers or inorganic fillers can be used either individually or as mixtures. The fillers f) are preferably added in amounts of from 0 to 50 wt. %, preferably of from 0 to 30 wt. %, based on 100% by weight of the sum of reaction components b) through g).
[0049] The auxiliary substances and additives, i.e. component g), which are optionally used concomitantly include e.g. stabilizers, coloring agents, flameproofing agents, plasticizers and/or monohydric alcohols.
[0050] The stabilizers used are preferably surface-active substances, i.e. compounds which serve to assist the homogenization of the starting materials and are optionally also suitable for regulating the cellular structure of the plastics. Examples which may be mentioned are emulsifiers such as, for example, the sodium salts of sulfated castor oil or fatty acids and salts of fatty acids with amines, foam stabilizers such as siloxane/alkylene oxide copolymers, and cell regulators such as paraffins. The stabilizers used are predominantly water-soluble organopolysiloxanes. These include polydimethylsiloxane residues onto which a polyether chain of ethylene oxide and propylene oxide is grafted. The surface-active substances are preferably added in amounts of from 0.01 to 5.0 wt. %, preferably of from 0.1 to 1.5 wt. %, based on 100% by weight of the sum of reaction components b) through g).
[0051] Coloring agents which can be used as an additive, i.e. component g), include organically and/or inorganically based dyestuffs and/or colored pigments which are known per se as suitable for coloring polyurethanes. Examples of these include iron oxide and/or chromium oxide pigments and phthalocyanine-based and/or monoazo-based pigments.
[0052] Examples of suitable flameproofing agents which are optionally to be used concomitantly are tricresyl phosphate, tris-2-chloroethyl phosphate, tris-chloropropyl phosphate and tris-2,3-dibromopropyl phosphate. Apart from the halogen-substituted phosphates already mentioned, it is also possible to use inorganic flameproofing agents such as hydrated aluminium oxide, ammonium polyphosphate, calcium sulfate, sodium polymetaphosphate or amine phosphates, e.g. melamine phosphates.
[0053] Examples of plasticizers which may be mentioned as suitable additives, i.e. component g) herein, are esters of polybasic or, preferably, dibasic carboxylic acids with monohydric alcohols. The acid component of such esters can be derived e.g. from succinic acid, isophthalic acid, trimellitic acid, phthalic anhydride, tetrahydrophthalic and/or hexahydrophthalic anhydride, endo-methylenetetrahydrophthalic anhydride, glutaric anhydride, maleic anhydride, fumaric acid and/or dimeric and/or trimeric fatty acids, optionally mixed with monomeric fatty acids. The alcohol component of such esters can be derived, for example, from branched and/or unbranched aliphatic alcohols having from 1 to 20 carbon atoms. Such alcohols include methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, tert-butanol and the various isomers of pentyl alcohol, hexyl alcohol, octyl alcohol (e.g. 2-ethylhexanol), nonyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol and stearyl alcohol, and/or from fatty and waxy alcohols that are naturally occurring or obtainable by the hydrogenation of naturally occurring carboxylic acids. Other possible alcohol components are cycloaliphatic and/or aromatic hydroxyl compounds, e.g. cyclohexanol and its homologues, phenol, cresol, thymol, carvacrol, benzyl alcohol and/or phenylethanol. Other possible plasticizers are esters of the above-mentioned alcohols with phosphoric acid. Optionally, phosphoric acid esters of halogenated alcohols, e.g. trichloroethyl phosphate, can also be used. In the latter case a flame-inhibiting effect can be achieved at the same time as the plasticizing effect. Of course, mixed esters of the above-mentioned alcohols and carboxylic acids can also be used. The plasticizers can also be so-called polymeric plasticizers, e.g. polyesters of adipic, sebacic and/or phthalic acid. Alkylsulfonic acid esters of phenol, e.g. phenyl paraffinsulfonate, can also be used as plasticizers.
[0054] Other auxiliary substances and/or additives g) which are optionally to be used concomitantly are monohydric alcohols such as butanol, 2-ethylhexanol, octanol, dodecanol or cyclohexanol, which can optionally be used concomitantly to bring about a desired chain termination.
[0055] The auxiliary substances and/or additives g) are preferably added in amounts of from 0 to 25 wt. %, more preferably of from 0 to 10 wt. %, based on 100% by weight of the sum of reaction components b) through g). Further information on the conventional auxiliary substances and additives, i.e. component g) herein, can be found in the scientific literature, e.g. in Kunststoff-Handbuch, volume VII “Polyurethane”, 3rd edition, Carl Hanser Verlag, Munich/Vienna, 1993, page 104 et seq.
[0056] In principle, the polyurethane foams suitable herein can be produced in a variety of ways, including, for example, by the one-shot process or the prepolymer process. In the one-shot process, all the components, e.g. polyols, polyisocyanates, chain extenders, blowing agents, catalysts, fillers and/or additives, are brought together and intimately mixed. In the prepolymer process, the first step is to prepare an NCO prepolymer by reacting part of the polyol component with all the polyisocyanate component, after which the remainder of the polyol and any chain extenders, blowing agents, catalysts, fillers and/or additives are added to the resulting NCO prepolymer and intimately mixed. A particularly preferred process in terms of the present invention is one in which the components b) through g) are mixed to form a so-called “polyol component”, which is then processed with the polyisocyanate and/or NCO prepolymer used as component a). The chain extenders, blowing agents, catalysts, fillers, auxiliary substances and/or additives which are optionally to be used concomitantly are generally added to the “polyol component”, as described above, although this is not absolutely necessary because any of the components which are compatible with the polyisocyanate component a) and do not react therewith can also be incorporated into the polyisocyanate component a).
[0057] In accordance with the present invention, the mixture formed by thorough mixing of the polyurethane foam forming reaction components is applied to the ballast stones, for example, by the pouring process, where the feeding, proportioning and mixing of the individual components or component mixtures are effected by means of the devices known per se in polyurethane chemistry. The amount of mixture introduced is generally proportioned so that the polyurethane foam has a free-rise density of from 20 to 800 kg/m 3 , preferably of from 30 to 600 kg/m 3 and more preferably of from 50 to 300 kg/m 3 . The starting temperature of the reaction mixture applied to the ballast stones is generally chosen in the range from 20 to 80° C., preferably from 25 to 40° C. The ballast stones are optionally dried and heated before the reaction mixture is introduced. Depending on the reaction components, the catalysts added and the temperature control, the solidification time (i.e. curing time) of the polyurethane foam can range from 15 to 45 seconds, and preferably from 15 to 30 seconds. Longer solidification times are possible, but not economical.
[0058] The present invention will be illustrated in greater detail with the aid of the Examples below.
[0059] The following examples further illustrate details for the process of this invention. The invention, which is set forth in the foregoing disclosure, is not to be limited either in spirit or scope by these examples. Those skilled in the art will readily understand that known variations of the conditions of the following procedures can be used. Unless otherwise noted, all temperatures are degrees Celsius and all parts and percentages are parts and percentages by weight, respectively.
EXAMPLES
[0060] The following components were used in Examples 1 to 9:
Polyol 1: a polyetherpolyol prepared by the propoxylation of 1,2-propylene glycol and subsequent ethoxylation; having an OH number of 28 and a functionality of 2. Polyol 2: a polyetherpolyol prepared by the propoxylation of glycerol and subsequent ethoxylation; having an OH number of 35 and a functionality of 3. Polyol 3: a polyetherpolyol prepared by the propoxylation of glycerol and subsequent ethoxylation; having an OH number of 27.5 and a functionality of 3. Polyol 4: a polyetherpolyol prepared by the propoxylation of glycerol and subsequent ethoxylation; having an OH number: 28 and a functionality of 3. Polyol 5: a polyetherpolyol prepared by the propoxylation of sorbitol and subsequent ethoxylation; having an OH number: 28.5 and a functionality of 6. Polyol 6: a polyurea filled polyetherpolyol (polyurea dispersion (PHD), solids content about 20%), prepared by the propoxylation of glycerol and subsequent ethoxylation; having an OH number of 28, a viscosity (at 25° C.) of 3600 mPa·s and a functionality of 3; commercially available as Desmophen® VP.PU7619W from Bayer MaterialScience AG. Chain Extender 1: a polyetherpolyol prepared by the propoxylation of trimethylolpropane; having an OH number: 550. Chain Extender 2: 1,4-butanediol; having an OH number: 1245. Chain Extender 3: monoethylene glycol; having an OH number: 1813. Chain Extender 4: a mixture of triethanolamine (55 wt. %) and diisopropanolamine (45 wt. %); having an OH number: 1160. Catalyst 1: dibutylbis[dodecylthio]stannane (commercially available as Fomrez® UL1 from GE Bayer Silicones) Catalyst 2: bis(dimethylaminoethyl) ether (commercially available as NIAX® A-1 from GE Bayer Silicones) Catalyst 3: triethylenediamine (commercially available as Dabco® S-25 from Air Products) Catalyst 4: tin octanoate (commercially available as Addocat® SO from Rhein Chemie Rheinau) Catalyst 5: triethylenediamine (commercially available as Dabco® 33-LV from Air Products) Catalyst 6: tin ricinoleate (commercially available as Kosmos® EF from Goldschmidt) Catalyst 7: N,N,N′-trimethyl-N′-hydroxyethylbisaminoethyl ether (commercially available as Jeffcat® ZF-10 from Huntsman) Stabilizer 1: TEGOSTAB® B8719LF (commercially available from Goldschmidt AG; an organo-modified polysiloxane) Stabilizer 2: TEGOSTAB® B8681LF (commercially available from Goldschmidt AG; an organo-modified polysiloxane) Isocyanate 1: an isocyanate prepolymer having an NCO group content of 19.8% and a viscosity at 25° C. of 700 mPa·s; prepared from 4,4′-MDI, carbodiimide-modified 4,4′-MDI and a polyoxyalkylenepolyolhaving an OH number of 164; commercially available as Desmodur® VP.PU10IS14 from Bayer MaterialScience AG. Isocyanate 2: an isocyanate prepolymer having an NCO group content of 24.5% and a viscosity at 25° C. of 440 mPa·s; prepared from an MDI mixture obtained by the phosgenataion of aniline/formaldehyde condensation products and polyoxyalkylenediols having an OH number of 515; commercially available as Desmodur® PA09 from Bayer MaterialScience AG. Isocyanate 3: an isocyanate prepolymer having an NCO group content of 28.4% and a viscosity at 25° C. of 91 mPa·s; prepared from an MDI mixture obtained by the phosgenation of aniline/formaldehyde condensation products and a polyetherpolyol having an OH number of 28; commercially available as Desmodur® VP.PU1805 from Bayer MaterialScience AG. Isocyanate 4: a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate having an NCO group content of 48% and a viscosity at 25° C. of 3 mPa·s; commercially available as Desmodur® T80 from Bayer MaterialScience AG.
Procedure:
[0084] The first step of the preparation of the so-called “polyol component” was to homogenize x parts by weight of polyetherpolyol and any chain extender, catalyst, stabilizer and blowing agent (see Table 1 for mixing proportions). Then, y parts by weight of polyisocyanate were added (see Table 1 for mixing proportions), and the ingredients were mixed for 10 seconds (using a PENDRAULIK LM34 laboratory mixer, at 3000 rpm). The initiation time and curing time were determined from the start of stirring.
[0085] The following properties of the resulting polyurethane foams were determined: free-rise density (according to DIN EN ISO 845), compression set (CS; according to DIN EN ISO 1856), compression force (according to DIN EN ISO 3386-1-98), compression hardness (according to DIN EN ISO 3386-1-98) and tensile strength (according to DIN EN ISO 1798). The CS value was determined one day after compression under the conditions given in Table 1. The compression force value was determined using a polyurethane foam sample with a base area of about 64 cm 2 .
[0000]
TABLE 1
Example
1*
2*
3
4
5
6
7
8
9
Polyol 1
37.8
40.8
42.6
50
50
50
69.6
Polyol 2
30
30
33
41.5
44.8
42.7
95.3
Polyol 3
23
Polyol 4
25
Polyol 5
44.65
Polyol 6
25
Chain Extender 1
30
27
22
Chain Extender 2
4
5
Chain Extender 3
2
4
4
Chain Extender 4
1.5
Catalyst 1
0.1
0.1
0.1
0.3
Catalyst 2
0.7
0.7
0.7
0.9
0.3
0.4
Catalyst 3
1.0
1.0
1.2
1.2
1.4
0.7
Catalyst 4
0.4
Catalyst 5
0.2
Catalyst 6
0.9
Catalyst 7
3.0
Stabilizer 1
0.3
Stabilizer 2
0.25
Water
0.4
0.4
0.4
0.4
0.3
0.3
0.4
3.3
3.0
Isocyanate 1
48
Isocyanate 2
68
60
56
47
40
42
Isocyanate 3
64
Isocyanate 4
40
free-rise density
200
218
220
190
221
224
230
58
30
[kg m −3 ]
Initiation time [s]
10
10
10
10
10
10
10
8
10
Curing time [s]
40
40
40
40
40
40
40
40
60
CS (40%, 25° C.,
7.5
0.4
0
0
0
0
0
0
0
5 min) [%]
Compression
3300
1300
740
96
147
70
73
23
11
force (10%) [N]
Compression
675
376
197
27
23
11
21
4.8
2.3
hardness (10%)
[kPa]
Tensile strength
1.23
0.95
0.76
0.32
0.23
0.29
0.48
0.17
0.10
[MPa]
In all of Examples 1 to 9 the index was adjusted to 100.
In Comparative Examples 1* and 2* foams with compression set were obtained (CS > 0.01%).
[0086] These foams are unsuitable for the consolidation of ballast stones for ballast. In Examples 5 and 6 incorporable catalysts were used to give foams with a low proportion of emissible or mobilizable ingredients.
[0087] With the reaction mixtures of Examples 3 to 9 according to the invention, ballast can be stabilized outstandingly well, even in the long term.
[0088] Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims. | The present invention relates to ballast which have a high stability and a long service life and to a process for the production of ballast. These ballast are suitable for railway track laying and road construction and dike systems used for example in costal protection. These ballast comprise ballast stones and polyurethane foams based on a reaction mixture of selected polyisocyanates and selected compounds with isocyanate-reactive groups. | 4 |
This application claims priority based on french patent application FR 03/02029 filed Jul. 4, 2002 and PCT application WO 2004/005639 A1 filed Jul. 4, 2003.
FIELD OF THE INVENTION
The invention concerns a filtering wall for expendable forms.
It also concerns forms equipped with the filtering wall as well as the fabrication process.
It also concerns the means of fabricating the filtering wall.
BACKGROUND OF THE INVENTION
Two types of forms are used to construct concrete work.
The first type is comprised of reusable forms that form a rigid watertight pocket that concrete is poured into.
Steel sheets attached to a bearing structure form the liner walls.
This type of form presents several disadvantages, including:
forms that are quite heavy in order to resist the hydrostatic forces, the custom of using fast-set concretes whose resistance stresses exceed requirements, etc.
In order to resolve these different problems, the second type of form appeared, namely expendable forms with filtering walls.
The concept of these filtering walls was developed to create different products (FR-A-2.675.181 et FR-A-2.647.839).
In particular, these filtering walls can be used to reduce the weight of forms.
The “form/filling” composite presents improved mechanical properties compared to a shell made by traditional means.
The first forms primarily used metal installed to create the desired permeability in the liner skin.
To create the liner skin on a form wall, several metal plates have to be installed to obtain the desired surface.
In addition, in these types of form, since part of the metal structure is not covered by a regulatory coating, it presents long-term durability risks.
Consequently, the structural calculations cannot take the metal structure into account.
In addition, the installed metal skin, even when protected against corrosion, can lead to damage due to corrosion phenomena.
In order to compensate for these disadvantages, there is an expendable form with a filtering skin (FR-A-2.800.109) that, in place of the installed metal, uses a mesh or fabric with wide panels obtained by interlacing warp and weft strands.
The size of the mesh panels is determined by the aggregates and desired filtering.
According to this solution, since the mesh is flexible when it is attached to the form's reinforcement, it is stretched in the two perpendicular directions to obtain uniform tension in the warp and weft strands in both directions.
In addition, spacers keep the liner skin away from the reinforcement.
The disadvantage of this type of form is that it over-consumes mesh and positions the mesh such that it hinders filling the form.
In effect, part of the mesh penetrates into the volume to be filled, which poses a problem.
SUMMARY OF THE INVENTION
The invention aims to resolve the aforementioned disadvantages.
To this end, the invention concerns a filtering wall for an expendable form comprised of a mesh formed by assembling flexible warp and weft yarns, said mesh being stretched on a so-called shape-retaining structure and the filtering wall being characterized in such a way that:
some of the warp strands are more resistant than the other warp strands, the mesh being tensioned by traction exerted solely on said more resistant warp strands, and it includes tension-maintaining means that associate the more resistant strands with the shape-retaining structure, said tension-maintaining means delimiting a larger panel than the one resulting from the initial interlacing of the warp and weft strands.
The invention also concerns a form equipped with a liner wall and the means of fabricating the said liner wall.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE INVENTION
The invention can be understood based on the description provided hereafter as a non-limiting example and the drawing attached hereto that schematically shows:
FIG. 1 : an installation to implement the process,
FIG. 2 : an installation detail,
FIG. 3 : a filtering wall,
FIG. 4 : a representation of the mesh deformation,
FIG. 5 : a connection means or clamp,
FIG. 6 : a section of a pressure bar,
FIG. 7 : a section of a support bar,
FIG. 8 : a pressure bar installation station,
FIG. 9 : a close up view of a detail in FIG. 8 ,
FIG. 10 : a front view of the roller,
FIG. 11 : a side view of the roller,
FIG. 12 : a perspective view of the backing roller,
FIG. 13 : a means of pre-tensioning,
FIG. 14 : a detail of the support bars' installation,
FIG. 15 : a section view of the completed assembly.
DETAILED DESCRIPTION OF THE INVENTION
By referring to the drawing, one sees a lining and filtering wall hereinafter referred to as filtering wall ( 1 ) for clarity, and intended to equip an expendable form.
The filtering wall ( 1 ) acts as a filter and depending on the size of panels ( 102 ), allows excess humidity to escape.
Typically, the filtering wall ( 1 ) includes a mesh ( 2 ) formed by assembling flexible warp strands comprised of the more resistant warp strands ( 2 A), regular warp strands ( 2 B), and weft strands ( 2 C), with the mesh ( 2 ) being tensioned on a shape-retaining structure ( 90 ). It is understood that the term shape-retaining is not to be taken literally, but rather in the sense that the deformation related to the tension is extremely low.
This filtering wall ( 1 ) is then attached to a bearing structure ( ) not shown) in order to establish an expandable form and from which other filtering walls ( 1 ) can be linked to.
According to a characteristic of the filtering wall ( 1 ):
more resistant warp strands ( 2 A) are more resistant than the regular warp strands ( 2 B), the mesh ( 2 ) being tensioned by traction exerted solely on the more resistant warp strands ( 2 A), and it includes tension maintaining means ( 3 , 4 , 5 ) for maintaining the tension that associates the more resistant strands ( 2 A) with the shape-retaining structure and created by the cooperation of linking means ( 3 ) acting as a clamp of sort; pressure bars ( 4 ); and support bars ( 5 ) which, together with the mesh ( 2 ), delimit a larger panel ( 102 ) than the one resulting from the initial interlacing of regular warp strands ( 2 B), and weft strands ( 2 C).
The tension and thus the deformation are determined between two consecutive tension-maintaining means ( 3 , 4 , 5 ). More precisely, the principle does not involve exerting tension between the ends of the mesh ( 2 ) then implementing the tension maintaining means ( 3 , 4 , 5 ), but on the contrary, fixing one end of the mesh ( 2 ) with the tension maintaining means ( 3 , 4 , 5 ), then exerting a tension force to fix the subsequent tension maintaining means ( 3 , 4 , 5 ).
By pressing on these new fixed points, one exerts a new tension, thereby locking the mesh ( 2 ) with the tension maintaining means ( 3 , 4 , 5 ) and so on.
By proceeding this way, one obtains the same tension in each panel ( 102 ), thereby defining the size of the panels ( 102 ).
Since the tension exerts on the more resistant warp strands ( 2 A), the single warp strand ( 2 B) and the weft strands ( 2 C) located in the previously defined panel ( 102 ) will arrange themselves based on an iso-stressed distribution as shown in FIG. 4 .
The panel ( 102 ) is defined by four points A 1 , A 2 , B 1 and B 2 before it is tensioned. When one only pulls points B 1 and B 2 towards B′ 1 and B′ 2 , the weft strands ( 2 C) deform (finer lines), bending with a neutral strand in the middle of the panel ( 102 ). This layout spreads the constraints decreasingly from the edge of the panel ( 102 ), which allows, under pressure, increasing deformations towards the center of the panel ( 102 ).
Under pressure from concrete, the liner side defined by a panel ( 102 ) is no longer flat but bulged out. This lets one optimize the quantity of filler then used to obtain a finished surface.
The value of the deformation is determined by the relationship between the elasticity of the more resistant warp strands ( 2 A) compared to the regular warp strands ( 2 B). So that each panel ( 102 ) is independent, the more resistant warp strands ( 2 A) shall not be common to two side-by-side panels ( 102 ) and, consequently, the mesh ( 2 ) shall include pairs of resistant strands ( 2 A). The distance between the more resistant warp strands ( 2 A) in a pair will depend on the tension maintaining means ( 3 , 4 , 5 ).
These more resistant warp strands ( 2 A) are either larger strands, made from another material or more generally comprised of a group of close-set strands.
The tension-maintaining means ( 3 , 4 , 5 ) include:
on one side of the mesh ( 2 ), pressure bars ( 4 ) that extend along one of the mesh's ( 2 ) axes, on the other side of the mesh ( 2 ), support bars ( 5 ) that extend perpendicularly to the direction of the pressure bars ( 4 ), and at the panel ( 102 ) corners, are the linking means ( 3 ) for connecting the pressure bars ( 4 ) and support bars ( 5 ) together thereby forming at these connection points a grip that blocks the mesh ( 2 ).
These pressure bars ( 4 ) and support bars ( 5 ) and connection means ( 3 ) constitute the shape-retaining structure ( 90 ). The mesh ( 2 ) is not installed on a pre-formed shape-retaining structure ( 90 ), but rather this shape-retaining structure ( 90 ) is formed at the same time as the filtering wall ( 1 ).
In order to improve the locking of the mesh ( 2 ) at the four corners of the panel ( 102 ), the pressure bar ( 4 ) can include grooves ( 4 A).
The pressure bar ( 4 ) is triangular shaped and the outside face of the base is grooved ( 4 A).
The pressure bar ( 4 ) has an axial cavity ( 4 B) to make it flexible.
The support bars ( 5 ) are in pairs (i.e.; a linking means ( 3 ) holds one pressure bar ( 4 ) and two support bars ( 5 ).
Now we will describe in detail the linking means ( 3 ). Moreover it is specified that in order to prevent any risk of disorder caused by the elements coming unfastened during transportation, this system may be completed by a positive locking system, bonding or welding. The connection means ( 3 ) appears as a clamp intended to overlap the pressure bar ( 4 ) and includes two legs ( 3 A) with a stop face ( 3 B) for the pressure bar ( 4 ) and, on the outside, on each of the arms' ( 3 A) outside faces, a support surface ( 3 C) for the support bars ( 5 ). The pressure bar ( 4 ) slides between the legs ( 3 A). A bolt ( 3 D) prevents the support bars ( 5 ) from sliding laterally. The bolt ( 3 D), formed by a bump, is next to one of the support surfaces ( 3 C). The support bar ( 5 ) is loaded by rotating around its base.
Therefore, to this end, one will note that this support bar ( 5 ) has rounded faces and is flexible so it can deform elastically. Viewed as a section, it is shaped like a figure eight. Potential cavities provide the desired compressibility. This is also an advantage because these pressure bars ( 4 ) and support bars ( 5 ) can be delivered wound on a reel.
During fabrication, one will use the linking means ( 3 ) and support surface ( 3 C) as a tooth to advance the filtering wall ( 1 ). It should be noted that the legs ( 3 A) ends are equipped with lateral notches ( 3 E) to attach to a “Tor” iron bar on the form-bearing structure.
To fabricate the filtering wall ( 1 ), one uses a set of means. These means include:
a mesh ( 2 ) wound around a shaft serving as a supply source ( 20 ), ahead of this supply source ( 20 ), a tensioning assembly ( 30 ), and a positioning assembly ( 40 ) to install the shape-retaining structure ( 90 ).
A cutting station ( 50 ) set at the appropriate length is provided ahead of the filtering wall ( 1 ) assembly stations.
The shape-retaining structure ( 90 ) is installed progressively by positioning the connecting means ( 3 ) on the tensioned mesh ( 2 ) and then installing the pressure bar ( 4 ) followed by the support bars ( 5 ).
The tensioning assembly ( 30 ) are divided into two tensioning zones ( 30 A and 30 B) that are spread on both sides of a tool ( 41 ). One is placed just behind the mesh ( 2 ) wound on its supply source ( 20 ) and the other, even with the equipped and thus completed mesh ( 2 ).
The tensioning assembly ( 30 ) exerts a traction force on the mesh ( 2 ), which is locked in a straight line by one of the tool's ( 41 ) systems. The traction force is determined by the number of panels ( 102 ) between the two tensioning zones ( 30 A, 30 B) in proportion to the desired lengthening of one panel ( 102 ).
The straight-line locking of the mesh ( 2 ) located in the pre-tensioning zone ( 30 B) includes a roller ( 31 ) and a backing roller ( 32 ), each equipped with grooves ( 33 ) so the linking means ( 3 ) can pass freely.
The roller ( 31 ) and backing roller ( 32 ) pinch the mesh ( 2 ). A drive system (e.g.; by constant torque) is used to apply a constant pre-determined force on the warp strands ( 2 A, 2 B).
The roller ( 31 ) and backing roller ( 32 ) are motorized and can advance the mesh ( 2 ) progressively.
The roller ( 31 ) and/or backing roller ( 32 ) can be comprised of cable rollers ( 70 ) aligned on a shaft. The cable roller ( 70 ) is mounted in addition on arms ( 100 ).
The outside face of the cable rollers ( 70 ) and/or roller ( 31 ) and backing roller ( 32 ) will be in material that can be deformed elastically so that it engages the mesh ( 2 ) sufficiently. The diameter will be defined to engage a sufficient length of the mesh's ( 2 ) surface. In the pre-tensioning zone ( 30 A), in a preferred form of advancing and tensioning the mesh ( 2 ), the tensioning assembly ( 30 ) is comprised of a set of two fixed rollers ( 34 , 35 ) between which a mobile roller ( 36 ) is located between two positions (dotted lines), one upper position that starts unwinding a mandrel ( 91 ) the mesh ( 2 ) is wound on and the other lower position that stops the mandrel's ( 91 ) unwinding. The mesh ( 2 ) then forms a “V”. The pre-traction force on the mesh ( 2 ) is provided either by the simple weight of the mobile roller ( 36 ) or this weight is completed by springs or other traction means like jacks, etc. The tension is then determined by the means spread out ahead of the tool ( 41 ).
After the pre-tensioning zone ( 30 A), which in particular controls the unwinding of the mesh ( 2 ) from the supply source ( 20 ) it is wound on, there is a mesh ( 2 ) advance system and a linking means ( 3 ) installation system. This installation system consists of wheels ( 42 ) spread along an axis transverse to the mesh's ( 2 ) direction of movement.
There are as many wheels ( 42 ) as linking means ( 3 ) to be positioned transversally.
All of the wheels ( 42 ) are united in rotation and driven by a suitable irreversible system (e.g.; a stepper motor) that authorizes one rotation corresponding to a step of the mesh ( 2 ).
Each wheel ( 42 ), whose circumference is a multiple of the panels' ( 102 ) step, includes evenly spaced notches ( 43 ) that can accommodate the head of each linking means ( 3 ).
Laterally to these wheels ( 42 ) and in the area of the notches ( 43 ), the system includes guides ( 44 ) for the pressure bars ( 4 ) that must be introduced in the linking means ( 3 ) heads. Therefore these guides ( 44 ) present a groove ( 45 ) whose shape is complementary to the outside of the pressure bars ( 4 ). In fact, the guides ( 44 ) are also used to assemble the wheels ( 42 ) together.
To introduce the pressure bars ( 4 ), the linking means ( 3 ) have to be pre-aligned because the mesh ( 2 ) and the shape of the notches ( 43 ) do not hold them adequately.
To this end, the machine includes an alignment system ( 46 ) to align all of the linking means ( 3 ) located on an axis.
This alignment system ( 46 ) includes an axle ( 47 ) on which are mounted pairs of spread disks ( 48 ), each pair of disks ( 48 ) being designed to laterally wedge a linking means ( 3 ) and that part of the axle ( 47 ) located between a pair of disks ( 48 ) so as to fit partially between the legs ( 3 A). One sees that these disks ( 48 ) have beveled sides ( 49 ) to facilitate centering the linking means ( 3 ). Teeth ( 60 ) driven by the wheels ( 42 ) are used to position, advance and immobilize the mesh ( 2 ) on the disks ( 48 ). The linking means ( 3 ) are installed by the bottom in the installation shown. This way one obtains a position along the two axes the time it takes to introduce the pressure bar ( 4 ) that comes from a section wound on a drum.
The pressure bar ( 4 ) is fed as follows.
Cable rollers ( 70 ) drive the section from a reel ( 69 ) up to the first stop ( 71 ).
When the alignment system ( 46 ) is in position, the first stop ( 71 ) is retracted and the cable rollers ( 70 ) push the pressure bar ( 4 ) through the linking means ( 3 ), guided by the guides ( 44 ), up to the second stop ( 72 ).
The pressure bar ( 4 ) is then cut and the first stop ( 71 ) is then put back in position.
As the pressure bars ( 4 ) are positioned, the support bars ( 5 ) have to be installed.
To do this, the support bars ( 5 ), wound on a reel ( 120 ), are progressively unwound flat and then pivoted 90° to until they are anchored in a freestanding position on the linking means ( 3 ).
The machine will then include a system to progressively unwind the support bars ( 5 ) and a means to position them.
Initially, the support bars ( 5 ) are guided so that they press against the linking mean's ( 3 ) support surfaces. The two support bars ( 5 ) then form a “V”.
A mechanical means, which, in a preferred embodiment is in the form of a grip ( 80 ) causes the support bars ( 5 ) to tip towards the linking means ( 3 ). The grip ( 80 ) has two jaws ( 81 ) closing in together.
By elastically deforming the pressure bar ( 4 ) and support bars ( 5 ), one then positions the support bars ( 5 ) in a freestanding position and grips the mesh ( 2 ). One sees that the action/reaction forces exerted on the support bars ( 5 ) are inclined vis-à-vis the linking means ( 3 ) median axis. As such, based on continuous elements mesh ( 3 ), support bars ( 5 ) and pressure bar ( 4 )), one can create a filtering wall ( 1 ) of suitable length that is only cut at the end of the assembly operation.
According to the fabrication process for a filtering wall ( 1 ):
one stretches a mesh ( 2 ) between two tension zones ( 30 A, 30 B) by exerting traction along more resistant warp strands ( 2 A) and regular warp strands ( 2 B), one positions the linking means ( 3 ) at certain points of the mesh ( 2 ) to delimit the panels ( 102 ), one aligns the linking means ( 3 ), one inserts, by sliding, the pressure bar ( 4 ) through the stop face ( 3 B), one positions the support bars ( 5 ) supported on the support surfaces ( 3 C), one tips the support bars ( 5 ) towards the linking means ( 3 ) median axis to form the grips with the linking means ( 3 ) and pressure bar ( 4 ), and one constitutes the filtering wall ( 1 ) continuously and progressively and then one cuts the filtering wall ( 1 ) to the desired dimensions.
The filtering wall ( 1 ) is then joined to a bearing structure to create an expendable form.
As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | The invention concerns a filtering wall designed for an expendable formwork comprising a lattice formed by assembling flexible warp and weft yarns, the lattice being stretched on an undeformable structure. The filtering wall is characterized in that some of the warp yarns are more resistant than other warp yarns, the lattice being stretched by traction solely exerted on the more resistant warp yarns and in that it comprises tension maintaining means for maintaining the tension associating the more resistant yarns with the undeformable structure, the tension maintaining means delimiting a larger mesh than the one resulting from the initial interlacing of the warp and weft yarns. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to food flavoring products and processes and, in particular, to a garlic product and process for making same.
[0002] Garlic has been used to flavor and enhance the taste of food for centuries and, relatively recently, science has shown what ancients intuitively knew: garlic contains high concentrations of health-giving ingredients.
[0003] Raw garlic, crushed garlic, cooked garlic, garlic salt, garlic powder, freeze-dried garlic and powdered garlic in capsules are but a few of the many forms in which garlic is commercially available.
[0004] Untreated raw garlic and certain forms of processed garlic have a bitterness and garlic flavor so strong that they are unpalatable to all but a relative few. For this reason, garlic is customarily cooked in some manner before being used with food. The traditional process required for preparing garlic for cooking and the cooking itself can be tedious and time-consuming.
DEFINITIONS
[0005] As used herein, the term “process-ready cloves” refers to washed and skinned cloves of garlic.
[0006] As used herein, the term “garlic bits” or “bits” refers to the form of garlic that results from cutting process-ready cloves into smaller pieces of generally uniform thickness.
[0007] As used herein with reference to bitterness and strength of garlic flavor in garlic bits, the term “reduced” means less than existed prior to garlic bits having been subjected to a reducing process.
[0008] As used herein, “garlic pieces” and “pieces” refer to garlic bits of reduced strength of garlic flavor and bitterness that have been fried.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The present invention provides ready-to-use garlic in the form of palatable, crispy, roasted-flavor pieces that can conveniently be stored and dispensed from a shaker. The garlic pieces of the present invention can be dispensed directly from a shaker onto food, either during or after its preparation, to lend the savory flavor of garlic.
[0010] When introduced into mashed potatoes, for example, the mashed potatoes are immediately imbued with the roasted flavor of toasted garlic with the added feature of lightly crunchy morsels. The same is true for salads, meat, poultry, fish and any other food with which garlic flavoring is desired.
[0011] In the present invention, garlic is processed into crispy pieces that not only provide a source of roasted garlic flavor to any food to which they are added, but also add nuggets of light crunchiness. During the process of the present invention, the strength of the raw garlic flavor is reduced to make the pieces more widely palatable. In addition, the bitterness which is a characteristic of raw garlic is also reduced below the level at which it is undesirable. In the present invention, both modifications to the palatability of the raw garlic are carried out without the use of leaching chemicals or unnatural additives. One end product of the present invention is garlic, with no additives other than the oil in which it is fried, in the form of crispy pieces with a roasted flavor that is palatable to a wide audience and that can be conveniently dispensed from a shaker. Another end product of the invention is garlic bits having reduced strength of garlic flavor and bitterness.
[0012] Accordingly, it is an object of the present invention to provide widely palatable, crispy pieces of roasted-flavor garlic ready for immediate use without further processing.
[0013] It is another object of the present invention to provide crispy pieces of garlic that have reduced bitterness and/or strength of garlic flavor.
[0014] It is yet another object of the present invention to provide a process for making crispy pieces of garlic from which the natural bitterness of the garlic has been reduced.
[0015] It is a further object of the present invention to provide a process for making crispy pieces of roasted-flavor garlic in which the strength of the flavor of the raw garlic has been reduced.
[0016] Another object of the present invention is to provide bits of garlic with reduced strength of garlic flavor and reduced bitterness.
[0017] The foregoing and other objectives, features and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0018] FIG. 1 is a flow chart schematically illustrating preferred embodiments of the process of the invention for making the products of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The basic steps in the process of one embodiment of the present invention include: (1) cracking harvested garlic bulbs into individual cloves that are then peeled and washed (process-ready cloves); (2) slicing and/or dicing the peeled and washed cloves into garlic bits of generally similar thickness; (3) reducing the bitterness and strength of the garlic flavor from the bits; and (4) frying the reduced bits into garlic pieces.
[0020] Referring to FIG. 1 , process 11 is initiated by step 12 which transforms harvested bulbs of garlic into skinned and washed garlic cloves. In ways known to those skilled in the art, the harvested garlic bulbs are cracked into individual cloves and the bulb's outer skins and root crowns removed. An air process can be used to remove the skins from the individual cloves, leaving skinned cloves which are then washed. Cloves with obvious defects are discarded.
[0021] In step 13 a , the process-ready cloves are cut into bits of a desired thickness as by a slicer. While the thickness can vary depending on the desired shape and size of the final product, pieces cut to a thickness of between approximately one-sixteenth and three-sixteenths of an inch have been found to produce excellent results. Regardless of the thickness selected, the best results are achieved when the bits have a generally uniform thickness so that later processing of the bits has a uniform effect. It will be understood by those skilled in the art that “generally uniform thickness” as used with reference to sliced garlic cloves can include variations within a range that still produces generally uniform results.
[0022] By step 13 b , the garlic is diced. Process-ready cloves from step 12 or sliced bits from step 13 a can be fed to a dicer where they are chopped into smaller size bits. Thus, in one embodiment of the invention, bits are formed by step 13 a alone. In yet another embodiment, process step 13 b follows process step 13 a . In yet another embodiment, process step 13 b follows step 12 and step 13 a is not employed. In all of the embodiments, however, garlic bits of generally uniform thickness result.
[0023] Slicing and dicing garlic cloves is known to those skilled in the art, as is the equipment for doing so and, thus, need not be described in further detail herein.
[0024] The garlic bits produced by step 13 a and/or step 13 b are then processed by step 14 in which the strength of the garlic flavor and the bitterness of the raw garlic bits are reduced. Because the bits have a generally uniform thickness, the reducing step will have a uniform effect on all of the bits.
[0025] In one embodiment of the invention, process step 14 is performed by blanching the garlic bits with heated water. The garlic bits can be blanched by immersion in a vat of heated water or by being carried on a conveyor where heated water is applied to the garlic bits. When immersed in a vat of heated water, the bits are retained in water at a temperature from approximately 170 to 195 degrees F. for 30 to 120 seconds. In some instances, boiling water can be used. Because garlic can vary in flavor strength and bitterness, depending on a number of factors including the season when they are harvested, the time between harvesting and processing and the variety of garlic, the optimal time and temperature will vary.
[0026] When blanching by applying heated water to garlic bits on a conveyor, the several variables mentioned above will dictate how long the bits are exposed to the heated water. In most cases, 30 to 120 seconds will suffice.
[0027] In another embodiment of the invention, step 14 is carried out by applying steam to the bits for 10 to 120 seconds.
[0028] Before being fried by step 16 , it is advantageous for the blanched garlic bits to be dried to remove any water remaining from the blanching process. This can be accomplished by exposure to ambient conditions for a few minutes, the use of warm air applied to the blanched garlic bits, shaking the garlic bits or any other method effective to remove moisture remaining from the reducing step 14 .
[0029] In another embodiment of the invention, step 14 reducing the bitterness and strength of the garlic flavor of the raw garlic bits is performed by baking rather than blanching. In this embodiment, garlic bits are placed on a conveyor that travels through an oven where the garlic bits are exposed to heat in the range of 200 to 600 degrees F. for a time period of 10 to 180 seconds. The particular temperature and time will depend on the factors mentioned above, as well as the desired characteristics of the finished product. For most applications, the baking process will not remove all of the moisture from the bits.
[0030] Because the bits have been formed to have a generally uniform thickness, the reducing step 14 , whether by blanching or baking, will operate generally uniformly on all of the bits to produce bits having substantially the same strength of garlic flavor and reduced bitterness. If, by contrast, the blanching process is applied to whole, process-ready cloves before they are formed into bits of generally uniform thickness, two adverse effects have been observed. Cloves, even from the same bulb, vary so much in size that blanching or baking them for the same time and temperature results in widely varying degrees of effectiveness in reducing the bitterness and the strength of garlic flavor. Also, in order to penetrate to the center of the cloves, the process would have to be carried out for so long and/or at such an elevated temperature that the outer portions of the cloves would be structurally broken down into a pulpy mass that could not be readily sliced and/or diced.
[0031] After step 14 , the garlic bits can be processed by step 16 in which they are fried. Frying the garlic bits transforms them into crispy, roasted-flavor pieces of garlic that are ready to use.
[0032] The following are two methods for carrying out step 16 . In one embodiment of the invention, garlic bits are placed in cooking oil at between 300 and 400 degrees F. The bits are left in the oil for 30 seconds to two and one-half minutes, depending on the size of the bits, the temperature of the oil, the degree of crispiness desired and the amount of roasted-flavor desired. In one embodiment, the bits are fried in oil at approximately 340 degrees F. for about one minute.
[0033] The oil used can be any oil typically used to fry foods. Safflower oil has the advantages of economy, a near neutral flavor and low absorption. Olive oil can add a more complex flavor. Other vegetable oils used for frying foods can also be used.
[0034] In another embodiment, step 16 is performed by applying frying oil to garlic bits while they are transported on a conveyor. The time that the frying oil is applied to the garlic bits will depend on such variables as the temperature of the oil, the size of the garlic bits, the degree of crispiness desired and the strength of roasted-flavor desired. In one embodiment, the garlic bits are exposed to the frying oil at between 300 and 400 degrees F. for 30 to 180 seconds, and preferably 340 degrees F. for 60 seconds.
[0035] In step 17 , any excess oil on the garlic bits is drained away and the bits cooled to room temperature. This step can be carried out by transporting the bits from the fryer on a three-layered belt chamber where the bits pass back and forth, removing excess oil and drying. The bits can then be conveyed into a cooling tunnel where ambient temperature air is blown on the bits to further cool and dry them.
[0036] In step 18 , the fried garlic bits can be sized by passing them through a screen of a selected size.
[0037] In an alternative embodiment, step 13 a is performed to create garlic bits that are slices of process-ready cloves of a selected thickness (e.g., one-eighth of an inch). These slices are processed by steps 14 , 16 and 17 as described above to create fried, crispy, roasted-flavor garlic pieces. Before these garlic pieces are sized by step 18 , however, step 19 is performed in which the fried garlic slices (pieces) are chopped into smaller random-size garlic pieces.
[0038] Of course, various changes, modifications and alterations in the teachings of the present invention may be contemplated by those skilled in the art without departing from the intended spirit and scope thereof. As such, it is intended that the present invention only be limited by the terms of the appended claims. | A form of garlic and process for making same in which cloves of garlic are cut into bits, blanched or baked to reduce the strength of the garlic flavor and bitterness, and then fried to produce ready-to-use, crunchy, roasted flavor garlic pieces that can be conveniently stored and dispensed from a shaker. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to wiretapping electronic communications, and in particular to a computer implemented method, data processing system, and computer program product for authenticating or “notarizing” packet traces.
2. Description of the Related Art
Wiretapping is the process of monitoring telephone or electronic communications by third party, often by covert means. This process of intercepting telephone conversations and electronic communications such as faxes, email, and other data transfers provides an effective investigation tool to be used by law enforcement agencies. To implement a wiretap, law enforcement agencies typically issue a wiretap request to the central office of the telephone companies or Internet Service Providers (ISPs). Examples of wiretapping products employed by law enforcement agencies to intercept electronic communications include Carnivore, which was developed by the U.S. Federal Bureau of Investigation, and Cyveillance, a commercial product. The Carnivore system is deployed at the ISP of the person for whom the law enforcement officials have wiretap authorization to snoop and store their communication traces. Both Cyveillance and Carnivore operate essentially as packet sniffers, which are programs that can “see” all of the information passing over a network to which it is connected. The program looks at, or “sniffs”, each packet as the data streams over the network. The wiretap devices look for packets or communication sessions with particular packet attributes and if found, save the sessions to disk or tape for later viewing and use in court proceedings. However, if the chain of custody of generated computer records such as these stored sessions cannot be proven, a court may consider such records as hearsay, and special arguments must be made to be able to introduce the records as evidence in court.
Existing methods in the current art for storing information related to a wiretap include hashing audit log records, using a hardware device to store the message digests of audit log records, integrating message digests into particular applications such as chat clients, and using a hardware device to store the message digests of a chat log. However, all of these existing methods typically store the wiretap information within a log and then perform a hash of the entire log. A hash function substitutes or transposes the data to create a digital “fingerprint”, or a hash value. A typical hash function comprises a short string of letters and numbers (binary data written in hexadecimal notation). When another hash value of the log is taken at a later time, the two hash values are compared. If the hash values match, the log is determined to be authentic. However, there may still be some question as to the authenticity of the data in a court of law since the computer data may potentially be altered prior to the initial hash of the complete log. There is currently no way to ensure that the data has not been altered or touched by someone in some way since the time it was collected.
SUMMARY OF THE INVENTION
The illustrative embodiments provide a computer implemented method, data processing system, and computer program product for authenticating or “notarizing” packet traces. In particular, the illustrative embodiments provide a network sniffer for capturing non-forgeable packet traces. Responsive to a start-up of the sniffer, a first quote of values is obtained from one or more platform configuration registers in a trusted platform module utilized by the sniffer, wherein the first quote comprises a list of starting values in the platform configuration registers, and wherein the first quote is signed by the trusted platform module and stored in a packet log. When a packet of interest is intercepted at the sniffer, the sniffer obtains a hash of the packet of interest. The sniffer then instructs the trusted platform module to extend a platform configuration register with the hash of the packet of interest by appending the hash of the packet of interest to the hash of the current value of the platform configuration register and hashing this value to create the new hash which is stored in the PCR. The sniffer may instruct the trusted platform module to extend the platform configuration register by calling a PCRExtend API. The packet of interest is then stored in the packet log. When the sniffer is shutdown, a second quote of values in the platform configuration registers is obtained, wherein the second quote comprises a list of current values in the platform configuration registers, and wherein the second quote is signed by the trusted platform module and stored in the packet log.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 depicts a pictorial representation of a distributed data processing system in which the illustrative embodiments may be implemented;
FIG. 2 is a block diagram of a data processing system in which the illustrative embodiments may be implemented;
FIG. 3 is a block diagram of an exemplary trusted platform architecture in which the illustrative embodiments may be implemented;
FIG. 4 is a block diagram illustrating an exemplary trusted platform architecture with which the illustrative embodiments may be implemented;
FIGS. 5A and 5B are block diagrams of known wiretapping configurations;
FIG. 6 is a block diagram of an exemplary wiretapping configuration comprising a secure non-repudiable sniffer in accordance with the illustrative embodiments;
FIGS. 7A and 7B depict an example log file in accordance with the illustrative embodiments;
FIG. 8 is a flowchart illustrating the sniffer logic in accordance with the illustrative embodiments; and
FIG. 9 is a flowchart illustrating the process of validating the proof of log correctness in accordance with the illustrative embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures and in particular with reference to FIGS. 1-2 , exemplary diagrams of data processing environments are provided in which illustrative embodiments may be implemented. It should be appreciated that FIGS. 1-2 are only exemplary and are not intended to assert or imply any limitation with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environments may be made.
With reference now to the figures, FIG. 1 depicts a pictorial representation of a network of data processing systems in which illustrative embodiments may be implemented. Network data processing system 100 is a network of computers in which embodiments may be implemented. Network data processing system 100 contains network 102 , which is the medium used to provide communications links between various devices and computers connected together within network data processing system 100 . Network 102 may include connections, such as wire, wireless communication links, or fiber optic cables.
In the depicted example, server 104 and server 106 connect to network 102 along with storage unit 108 . In addition, clients 110 , 112 , and 114 connect to network 102 . These clients 110 , 112 , and 114 may be, for example, personal computers or network computers. In the depicted example, server 104 provides data, such as boot files, operating system images, and applications to clients 110 , 112 , and 114 . Clients 110 , 112 , and 114 are clients to server 104 in this example. Network data processing system 100 may include additional servers, clients, and other devices not shown.
In the depicted example, network data processing system 100 is the Internet with network 102 representing a worldwide collection of networks and gateways that use the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, governmental, educational and other computer systems that route data and messages. Of course, network data processing system 100 also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIG. 1 is intended as an example, and not as an architectural limitation for different embodiments.
With reference now to FIG. 2 , a block diagram of a data processing system is shown in which illustrative embodiments may be implemented. Data processing system 200 is an example of a computer, such as server 104 or client 110 in FIG. 1 , in which computer usable code or instructions implementing the processes may be located for the illustrative embodiments.
In the depicted example, data processing system 200 employs a hub architecture including a north bridge and memory controller hub (MCH) 202 and a south bridge and input/output (I/O) controller hub (ICH) 204 . Processing unit 206 , main memory 208 , and graphics processor 210 are coupled to north bridge and memory controller hub 202 . Processing unit 206 may contain one or more processors and even may be implemented using one or more heterogeneous processor systems. Graphics processor 210 may be coupled to the MCH through an accelerated graphics port (AGP), for example.
In the depicted example, local area network (LAN) adapter 212 is coupled to south bridge and I/O controller hub 204 and audio adapter 216 , keyboard and mouse adapter 220 , modem 222 , read only memory (ROM) 224 , universal serial bus (USB) ports and other communications ports 232 , and PCI/PCIe devices 234 are coupled to south bridge and I/O controller hub 204 through bus 238 , and hard disk drive (HDD) 226 and CD-ROM drive 230 are coupled to south bridge and I/O controller hub 204 through bus 240 . PCI/PCIe devices may include, for example, Ethernet adapters, add-in cards, and PC cards for notebook computers. PCI uses a card bus controller, while PCIe does not. ROM 224 may be, for example, a flash binary input/output system (BIOS). Hard disk drive 226 and CD-ROM drive 230 may use, for example, an integrated drive electronics (IDE) or serial advanced technology attachment (SATA) interface. A super I/O (SIO) device 236 may be coupled to south bridge and I/O controller hub 204 .
An operating system runs on processing unit 206 and coordinates and provides control of various components within data processing system 200 in FIG. 2 . The operating system may be a commercially available operating system such as Microsoft® Windows® XP (Microsoft and Windows are trademarks of Microsoft Corporation in the United States, other countries, or both). An object oriented programming system, such as the Java™ programming system, may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 200 . Java and all Java-based trademarks are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both.
Instructions for the operating system, the object-oriented programming system, and applications or programs are located on storage devices, such as hard disk drive 226 , and may be loaded into main memory 208 for execution by processing unit 206 . The processes of the illustrative embodiments may be performed by processing unit 206 using computer implemented instructions, which may be located in a memory such as, for example, main memory 208 , read only memory 224 , or in one or more peripheral devices.
The hardware in FIGS. 1-2 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash memory, equivalent non-volatile memory, or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIGS. 1-2 . Also, the processes of the illustrative embodiments may be applied to a multiprocessor data processing system.
In some illustrative examples, data processing system 200 may be a personal digital assistant (PDA), which is generally configured with flash memory to provide non-volatile memory for storing operating system files and/or user-generated data. A bus system may be comprised of one or more buses, such as a system bus, an I/O bus and a PCI bus. Of course the bus system may be implemented using any type of communications fabric or architecture that provides for a transfer of data between different components or devices attached to the fabric or architecture. A communications unit may include one or more devices used to transmit and receive data, such as a modem or a network adapter. A memory may be, for example, main memory 208 or a cache such as found in north bridge and memory controller hub 202 . A processing unit may include one or more processors or CPUs. The depicted examples in FIGS. 1-2 and above-described examples are not meant to imply architectural limitations. For example, data processing system 200 also may be a tablet computer, laptop computer, or telephone device in addition to taking the form of a PDA.
In situations where computer records are routinely and automatically generated, the current standard required for showing chain-of-custody for computer records in a court of law is for a forensics collector to generate hash values for the computer records and show that the records shown in court have the same hash value as the collected records. However, the reliability and believability of current chain-of-custody evidence is based on the credibility of the forensics collector, since the records and the hashes may be tampered with by anyone who touches the records both during collection and after collection but before they are presented in court. Thus, the hashes may be validated only by assertion that everyone in the chain of custody acted honorably.
The illustrative embodiments address the problems in the current art by providing a computer implemented method, data processing system, and computer program product for authenticating or “notarizing” wiretaps of electronic communications. In particular, the illustrative embodiments enable network sniffers to apply a validation to computer records at the point of record collection, thereby allowing one to verify the authenticity of the packet traces for court proceedings. A sniffer is a program which monitors and captures data being transmitted on a network. With the illustrative embodiments, the reliability of the records may be increased by utilizing a hardware device, such as a Trusted Platform Module (TPM), in conjunction with a network sniffer to provide the capability of “notarizing” wiretaps. The hashing of the computer records in the illustrative embodiments is performed at record collection time, thereby allowing one to compare, at a later date, a running hash against the stored hash to verify that the records are authentic. In addition, as the hash values are stored in the TPM, the values cannot be tampered without subverting the hardware. For instance, when a quote is taken, the quote is signed with the TPM key, and the signing key never leaves the TPM. If the quote is altered, the signature will not validate the new (altered) quote.
A TPM is a microcontroller affixed to the motherboard of a PC which stores keys, passwords, and digital certificates and performs all cryptographic functions on the chip. Alternatively, the TPM may be implemented in software. The TPM validates the stored data packets in the wiretap using integrity measurements which require a root of trust within the computing platform. In order to determine the integrity of the stored data packets, a hardware or firmware component, called the Trusted Building Block (TBB) component, takes integrity measurements at the initial boot process of the sniffer to create the Core Root of Trust for Measurement (CRTM). The CRTM is the basis of the chain of trust. All software that is executed on the sniffer is then measured and becomes part of the chain of trust. The TBB component provides trusted measurement functions (e.g. Secure Hash Algorithm-1 (SHA-1)) to the rest of the platform. A packet measurement is a hash of the complete packet, including packet headers and payload. These measurements are stored in the TPM. The hashes are stored in protected registers called Platform Configuration Registers (PCRs). For example, when a packet is received at the sniffer, the sniffer measures the entire packet. The sniffer then extends a particular PCR. The TPM extends the PCR by appending the hash value taken from the packet to the current hash value of the PCR. The extended value is then rehashed to form a composite hash value for the PCR. These extended PCR values obtained at the time of packet collection may then be used to validate the authenticity of the stored packets in the packet log.
The sniffer is located at some point in the communications path between the sender and the receiver. The sniffer comprises wiretap software that is used to determine which packets traveling on the network match interest criteria and should be retained. The interest criteria used by the sniffer to determine which packets traveling on the network should be captured may include, but is not limited to, source or destination Internet Protocol addresses of the packets, keywords or phrases within the packet, as well as other packet attributes. The sniffer must have a TPM implementation and may operate either on the network with its network interface in promiscuous mode, or the sniffer may serve as the router or bridge.
During sniffer start-up time, a quote (measurement) of the initial PCR values signed by the key stored in the TPM is taken by the sniffer. This initial quote is the starting PCR values hashed together to form a composite initial PCR value. For example, the initial value of a PCR is normally either “0000000000000000000000000000000000000000” or “FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF”. Alternatively, if the PCR was previously extended, an example value may comprise “ea1a3901c085941efde6f198f4b62e2fc2a6ea94”. The initial quote is signed by the TPM to allow one to verify through a digital signature that the content of the packet log is accurate and has not been tampered with. As packets arrive at the sniffer, the sniffer identifies packets which match the interest criteria. If the sniffer makes a determination that a packet should be stored, the packet may be measured by the sniffer individually, or the sniffer may group packets of interest together for speed and measurement. The measurement is stored by extending a PCR with the hash value. Intermediary quotes may be taken of the PCR values. In this manner, a PCR may be extended as many times as necessary while maintaining the packet log. When the sniffer is shut down, a final quote is taken of the PCR values, which comprises the values hashed together to form a composite final PCR value. The final quote contains the measurement of the entire packet log.
When the packets are to be used as evidence in a court proceeding, the packets may be authenticated by re-running the packet log and validating that the resulting final PCR values match those from the final quote. If the calculated PCR value does not match the final quote value, then either the packet log or the quote has been tampered with since the time of collection. If the log has been tampered with, the packet log cannot be introduced as evidence in a court of law.
With reference now to FIG. 3 , a block diagram of an exemplary trusted platform architecture with which the illustrative embodiments may be implemented is shown. FIG. 3 depicts a trusted platform architecture in accordance with the Trusted Computing Group's (TCG) PC-specific implementation specification. It should be clear to one skilled in the art that the sniffer may alternatively be based on a server, virtual, mobile phone or similar platform.
System 300 supports execution of software components, such as operating system 302 , applications 304 , and drivers 306 , on its platform 308 . The software components may be received through a network, such as network 102 shown in FIG. 1 , or may be stored, for example, on hard disk 310 . Platform 308 receives electrical power from power supply 312 for executing the software components on add-on cards 314 and motherboard 316 , which includes typical components for executing software, such as CPU 318 and memory 320 , although motherboard 316 may include multiple CPUs. Interfaces 322 connect motherboard 316 to other hardware components within system 300 , and firmware 324 contains POST BIOS (power-on self-test basic input/output system) 326 .
Motherboard 316 also comprises trusted building block (TBB) 328 . Motherboard 316 is supplied by a manufacturer with TBB 328 and other components physically or logically attached and supplied by the manufacturer. TBB 328 comprises the combination of CRTM 330 , TPM 332 , the connection of CRTM 330 to motherboard 316 , and the connection of the TPM 332 to motherboard 316 . CRTM 330 is an immutable portion of the platform's initialization code that executes upon a platform reset event.
Turning now to FIG. 4 , a block diagram of an exemplary trusted platform module is shown. FIG. 4 illustrates components of a trusted platform module, such as TPM 332 in FIG. 3 , according to TCG specifications. As previously mentioned, TPM 400 is used in conjunction with a network sniffer to provide the capability of notarizing wiretaps.
TPM 400 comprises input/output component 402 , which manages information flow over communications bus 404 by performing appropriate protocol encoding/decoding operations and routing of messages to appropriate components. TPM 400 contains cryptographic processing capabilities. TPM 400 may also be implemented on a cryptographic co-processor 406 , such as PCI-X Cryptographic Coprocessor (PCIXCC). Key generator 408 creates symmetric keys and RSA asymmetric cryptographic key pairs. HMAC engine 410 performs HMAC (Keyed-Hashing for Message Authentication) calculations, whereby message authentication codes are computed using secret keys as integrity checks to validate information.
Random number generator 412 acts as a source of randomness for the computation of various values, such as keys or other values. SHA-1 engine 414 implements the SHA-1 hash algorithm. Power detector 416 manages the power states of TPM 400 in association with the power states of the platform. Opt-in component 418 maintains the state of persistent and volatile flags and enforces semantics associated with those flags such that TPM 400 may be enabled and disabled. Execution engine 420 runs program code to execute commands that TPM 400 receives through input/output component 402 . Non-volatile memory 422 stores persistent identity and state associated with TPM 400 . Non-volatile memory 422 may store static data items but is also available for storing dynamic data items by entities that are authorized by the TPM owner. Volatile memory 424 stores dynamic data items, including the Platform Configuration Registers, which are extended with the measurements of the packets of interest.
FIGS. 5A and 5B are block diagrams of known wiretapping configurations. In particular, FIG. 5A shows several computers linked together in a network. Computer 1 502 , computer 2 504 , and computer 3 506 are examples of data processing systems such as clients 110 - 114 in FIG. 1 connected by a network, such as network 102 . In this illustrative example, a data packet may be transmitted from computer 1 502 to computer 2 504 or computer 3 506 via Internet Service Provider (ISP) routers 508 and 510 . However, router 512 containing a sniffer (sniffer 514 ) is placed between computers 1 502 , 2 504 , and 3 506 . As the packet travels through router 512 , sniffer 514 captures all packets destined for computers 2 504 or 3 506 and examines the packet headers and/or content. Sniffer 514 is an “active” sniffer in that the sniffer receives packets intended for destination computers 2 504 and 3 506 and sends the packet to the destination computer after the packet header is analyzed. If a captured packet contains something of interest to the sniffer, the sniffer will first store the packet of interest in log 516 and then forward the packet to its intended destination computer, such as computers 2 504 or 3 506 .
Similar to FIG. 5A , FIG. 5B shows several computers, computer 4 522 , computer 5 524 , and computer 6 526 , connected in a network. A data packet may be transmitted from computer 4 522 to computer 5 524 or computer 6 526 via ISP routers 528 and 530 . In the configuration in FIG. 5B , however, the sniffer being used on the network is not located within a router as in FIG. 5A , but rather sniffer 532 is a “passive” sniffer and is located on the same network segment as one of the targeted computers or one of the routers along the path to the target computers. A passive sniffer does not directly intrude onto a foreign network or computer, and the activity of a passive sniffer is not detectable by the devices being observed. While computers 5 524 and 6 526 will accept only those packets from ISP router 530 which have packet header information indicating that the packet is intended for that particular computer, sniffer 532 accepts all packets and examines the packet headers and/or content. If a captured packet contains something of interest to sniffer 532 , the sniffer will store the packet of interest in log 534 .
FIG. 6 is a block diagram of an exemplary wiretapping configuration comprising a secure non-repudiable sniffer in accordance with the illustrative embodiments. The wiretapping configuration in FIG. 6 allows for intercepting and authenticating packet traces while the packet is transmitted from the source to the destination location, in contrast with the wiretapping configurations in FIGS. 5A and 5B which may authenticate the packet traces after the packets are stored. The drawback to the configurations in FIGS. 5A and 5B is that they leave a long window of vulnerability during which time the packet traces may have been undetectably altered. In addition, the authentication provided by the wiretapping configuration in FIG. 6 also allows for determining the router software and hardware which collected the packet trace.
In this illustrative example, a data packet may be transmitted from computer 1 602 to computer 2 604 or computer 3 606 via ISP routers 608 and 610 . All packets transmitted between computer 1 602 and computers 2 604 and 3 606 are intercepted by sniffer 612 . Sniffer 612 is a secure non-repudiable sniffer in that sniffer 612 allows packet trace measurements to be taken when the packets are collected, thereby increasing the reliability of the computer records for evidence purposes. It should be noted that although sniffer 612 is an active sniffer in the particular wiretapping configuration in FIG. 6 , the sniffer may also be implemented as a passive sniffer without departing from the spirit or scope of the illustrative embodiments.
TPM 614 is an example of a trusted platform module, such as TPM 400 in FIG. 4 . TPM 614 is connected to sniffer 612 and used to store and authenticate the trust measurements of the packets intercepted by sniffer 612 . Sniffer 612 may be placed at any point in the communications path between computer 1 602 and computer 2 604 or computer 3 606 . As a packet travels from computer 1 602 to computer 2 604 , sniffer 612 captures the packet and examines the packet header and/or content. If the captured packet contains something of interest to sniffer 612 , the sniffer will store the packet information of interest in signed log 616 and then send the packet to its intended destination computer, such as computers 2 604 or 3 606 without knowledge or consent of the computer owners. In contrast with log 516 in FIG. 5A and log 534 in FIG. 5B , log 616 contains the initial quote, the intermediary quotes, and the final quotes which form the basis for the strong authentication of the log.
FIGS. 7A and 7B depict an example log file in accordance with the illustrative embodiments. In particular, log file 700 represents a log file, such as log 616 in FIG. 6 . However, for purposes of illustration, log file 700 has been rendered human readable, and thus does not represent the actual contents of the log file in the preferred embodiment.
FIG. 8 is a flowchart illustrating the sniffer logic in accordance with the illustrative embodiments. The process begins with a trusted boot of the sniffer (step 802 ). In the trusted boot, the sniffer instructs the TPM to take an initial quote of the PCRs which comprises a hash of the starting values of the PCRs. The initial quote is then signed by the TPM and provided to the packet log (step 804 ). When a packet arrives at the sniffer (step 806 ), the sniffer determines whether the packet is a packet of interest (step 808 ). This determination may be made based on a set of interest criteria such as, for example, packet header information (e.g., IP source or destination address) or the content of the packet itself.
If the sniffer determines the packet is of interest (‘yes’ output of step 808 ), the sniffer then measures the packet by taking a hash of the entire packet (step 810 ). This hashed value measurement is then stored in a PCR by extending the current PCR value with the hashed value of the packet (step 812 ). The packet of interest is then stored in the packet log (step 814 ). The packet is then sent to its intended destination computer (step 816 ).
Turning back to step 808 , if the sniffer determines that the packet is not of interest (‘no’ output of step 808 ), the sniffer skips to step 816 and sends the packet to its intended destination.
The sniffer then makes a determination as to whether an intermediary quote should be taken of the stored packets (step 818 ). Intermediary quotes of the stored packets may be taken periodically and appended to the packet log. If the sniffer determines that an intermediary quote should not be taken (‘no’ output of step 818 ), the process continues to step 822 . However, if the sniffer determines that an intermediary quote should be taken (‘yes’ output of step 818 ), the sniffer instructs the TPM to take a quote of the PCR values and stores that quote in the packet log (step 820 ). A determination is then made as to whether the sniffer has been shut down (step 822 ). If the sniffer is not shut down (‘no’ output of step 822 ), the process loops back to step 806 and the sniffer waits for another packet to arrive. If the sniffer is shut down (‘yes’ output of step 822 ), then a final quote is taken (step 824 ), with the process terminating thereafter. The final quote of the stored packets may be appended to the packet log.
FIG. 9 is a flowchart illustrating the process of validating the proof of log correctness in accordance with the illustrative embodiments. The process in FIG. 9 may be implemented in the sniffer or may be a standalone process.
The process begins with the validator reading a first quote in the log (step 902 ). The validator verifies the signature of the quote using the sniffer TPM key to determine if the signature is valid (step 904 ) via standard digital signature technique. If the signature does not validate using the sniffer TPM key (‘no’ output of step 904 ), the validator determines that the log has been tampered with (step 906 ), and the process terminates thereafter.
If the signature validates using the sniffer key (‘yes’ output of step 904 ), the validator obtains the PCR values from the quote read from the log (step 908 ). The PCR values from the quote are then extended for each packet in the log (step 910 ). Subsequently, the next quote in the log is read by the TPM (step 912 ). The validator compares the signature of the next quote against the sniffer TPM key to determine if the signature is valid (step 914 ). If the signature does not validate using the sniffer key (‘no’ output of step 914 ), the TPM determines that the log has been tampered with (step 906 ), and the process terminates thereafter.
If the signature validates using the sniffer TPM key (‘yes’ output of step 914 ), a determination is made as to whether the PCR values of the first quote after having been extended with the each packet in the log up to the next quote is the same as the PCR values of the next quote (step 916 ). If the PCR values are different (‘no’ output of step 916 ), the validator determines that the log has been tampered with (step 906 ), and the process terminates thereafter.
If the PCR values are the same (‘yes’ output of step 916 ), then a determination is made as to whether the quote is the final quote in the log (step 918 ). If the quote is not the final quote (‘no’ output of step 918 ), the process loops back to step 910 where the PCR values are calculated for each packet in the log up to the next quote. If the quote is the final quote in the log (‘yes’ output of step 918 ), the validator determines that the entire log is valid (step 920 ), with the process terminating thereafter.
The invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc.
Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD.
A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution.
Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers.
Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters.
The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A system and method for capturing non-forgeable packet traces. Upon start-up of a sniffer, a first quote of Platform Configuration Register (PCR) values in a Trusted Platform Module (TPM) utilized by the sniffer is obtained, wherein the first quote comprises a list of starting values in the PCRs and is signed by the TPM and stored in a packet log. When a packet of interest is intercepted by the sniffer, the sniffer obtains a hash of the packet and instructs the TPM to extend a PCR with the hash value. The packet of interest is then stored in the packet log. When the sniffer is shutdown, a second quote of values in the PCRs is obtained, wherein the second quote comprises a list of current values in the PCRs, and wherein the second quote is signed by the TPM and stored in the packet log. | 7 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to the field of mining (e.g., extracting, drilling or recovering) hydrocarbons. Embodiments of the present invention relate to a system for extracting hydrocarbons (e.g., hydrocarbon-based fuels) from underground formations utilizing ultrasound, and methods of using the same. More specifically, embodiments of the present invention relate to a system and method for creating controlled fractures in underground geological formations, allowing the extraction of hydrocarbons trapped therein.
DISCUSSION OF THE BACKGROUND
[0002] Increasing demands for domestic fuel sources have led to widespread attention to a technique of underground natural gas and oil exploitation called hydraulic fracturing (fracking) While the technique has merit, environmental concerns have recently arisen regarding the environmental impacts of fracking, including possible contamination of ground water, surface water, and soil, as well as the release of greenhouse gases into the atmosphere. Additionally, current fracking techniques have several inefficiencies.
[0003] Natural underground oil shale and coal deposits offer an abundant supply of petroleum and natural gas resources. Many variables must be considered in the application of fracking techniques to extract these hydrocarbons. For instance, the question of whether the extraction of natural gas and hydrocarbons from a particular oil shale or coal bed formation is efficient and economical depends on the flow rate of these materials through the formation. Darcy's Law describes the flow rate of materials through porous media, which is measured in
[0004] Darcy (D). The flow rates of hydrocarbons in shale and coal bed formations is low (e.g., in the 1 nD to 1 μD range), due to the low permeability of shale and coal. Fracking of such underground formations must result in a flow rate of the hydrocarbons that is sufficient to extract economically sufficient amounts of the hydrocarbons.
[0005] To achieve such flow rates, wellbores are often drilled using vertical drilling techniques. In order increase flow rates to economical levels, underground formations are pumped with large amounts of water and chemicals (fracking fluids) at extreme pressures to achieve fracturing of the natural underground geologic formations. Materials known as proppants are then pumped into the newly created fractures to prop open the fractures, creating paths of least (or lower) resistance for hydrocarbons to flow.
[0006] However, fracking fluids typically include a wide range of potentially hazardous chemicals (e.g., acids, buffering agents, bactericides, corrosion inhibitors, friction reducers, surfactants, gelling agents, etc.). Large amounts of these fracking fluids can be used in a fracking operation (e.g., greater than 10 6 gallons in deep oil shale deposits). A portion of the fracking fluids can find its way into water and soil by leaking through waste pipelines transporting the fluid from the well to disposal areas and from the disposal areas themselves. Also, a portion of the fracking fluid injected into the well can remain underground. The chemicals in the fracking fluid can migrate into aquifers, surface water, and soils. Thus, the use of fracking fluids can result in the contamination of these important resources.
[0007] Presently, hydraulic fracturing techniques have multiple problems, including:
Low efficiency in capturing the released hydrocarbons; Due to economic considerations, once the flow rate of the well is past a premium flow rate, the well may be abandoned; Capping the abandoned well may not eliminate leeching of greenhouse gases into the atmosphere; If left uncapped, methane (CH 4 ) can leach from the well into the air, and methane is greater than 30 times more powerful in inducing greenhouse effects than CO 2 ; Ground and surface water and soil can be polluted by fracking fluid and chemicals released from wells; and Horizontal drilling techniques may result in seepage of natural gas into the environment, resulting in loss of potential revenue and significant risk of injury and death to local fauna.
[0014] An additional drawback to fracking is the release of Naturally Occurring Radioactive Materials (NORMS). These NORMS are salts of radioactive species which potentially can be solubilized in the presence of water. It is conceivable that ground water bodies may then be contaminated with labile radioactive species, lending to worsening environmental damages.
[0015] Thus, new techniques for extracting hydrocarbons that lower the costs, minimize environmental impacts, and increase the efficiency of extracting geologic hydrocarbons are needed.
SUMMARY OF THE INVENTION
[0016] Embodiments of the present invention are generally related to systems for extracting hydrocarbons (e.g., natural gas) from underground formations utilizing ultrasonic vibrations and methods of extracting hydrocarbons using such systems. More specifically, embodiments of the present invention relate to a system and method for creating controlled fractures in underground geological formations, allowing the extraction of hydrocarbons trapped therein.
[0017] In accordance with the present invention, a system for fracturing underground formations utilizing ultrasonic mechanical vibrations may comprise a plurality of piezoelectric devices for producing mechanical vibrations capable of fracturing underground geological formations, including oil shale, coal beds, sandstone, and other geological formations in which hydrocarbons may be deposited. The piezoelectric devices may be inserted into one or more wellbores, down to the position of a geological formation containing hydrocarbons, where the piezoelectric devices can be used to create ultrasonic vibrations in the wellbore to shake and expand existing fractures. The piezoelectric devices are also capable of sensing resonant vibration frequencies (typically ultrasonic) of existing fractures, which can be enlarged by pulsing the formation with the detected resonant frequency(ies).
[0018] The system may also include a reversible vacuum/pump system to create a path of least or lower resistance for hydrocarbons freed from the geological formation by the fracturing system, effectively drawing the hydrocarbons toward the surface. The vacuum/pump system may be further configured to flush an innocuous or relatively harmless fluid or gas (e.g., N 2 or air) into a wellbore as a proppant to prevent the fractures in the geological formation from (1) closing up and/or (2) trapping the hydrocarbons contained therein.
[0019] The fracturing system may be used in a method for extracting hydrocarbons from underground geological formations by (1) determining the resonant frequencies of the fractures present in the geological formation, (2) producing vibrations at the resonant frequencies in order to cause spreading and growth of the fractures and free the hydrocarbon deposits contained in the geological formation, (3) pumping a proppant from the surface into the fractures (e.g., through a wellbore) in order to maintain the enlarged fracture and facilitate the flow of hydrocarbons out of the formation, and (4) collecting the hydrocarbons (e.g., through the wellbore, optionally using [i] a negative pressure created in the wellbore by the vacuum/pump system and/or [ii] a higher pressure that may naturally be present in an underground hydrocarbon deposit).
[0020] In one embodiment, the present invention relates to a system for fracturing underground formations, comprising (a) a plurality of piezoelectric devices, the plurality of piezoelectric devices being capable of insertion into a plurality of underground wells in the underground formation and producing and detecting a broad range of vibrational frequencies; (b) an apparatus for receiving and interpreting data from the piezoelectric devices regarding detected vibrational frequencies; and (c) an apparatus for inducing vibrations of desired frequencies in the plurality of piezoelectric devices.
[0021] In another embodiment, the present invention relates to a system of extracting hydrocarbons from underground formations, comprising (a) a plurality of piezoelectric devices, the plurality of piezoelectric devices being capable of insertion into a plurality of underground wells in the underground formation and producing and detecting a broad range of vibrational frequencies; (b) an apparatus for inducing vibrations of desired frequencies in the plurality of piezoelectric devices; (c) an apparatus for pumping a proppant fluid into the plurality of underground wells; and (d) an apparatus for extracting hydrocarbons from the wells.
[0022] In another embodiment, the present invention relates to a method of enlarging fractures in underground geological formations, comprising embedding a plurality of piezoelectric devices capable of producing ultrasonic mechanical vibrations having (or within) a predetermined range of frequencies in wells exposing the underground formation; and inducing the mechanical vibrations in the wells using the piezoelectric devices to fracture the underground formation.
[0023] In another embodiment, the present invention relates to a method of extracting hydrocarbons from an underground geological formation, comprising (1) inserting a plurality of piezoelectric devices into a plurality of wells near a deposit of hydrocarbons in the underground formation, (2) inducing vibrations (e.g., within a predetermined frequency range) in the formation using the piezoelectric devices, (3) detecting vibrations reflected by the formation and determining the resonant frequencies of fractures in the formation, (4) inducing vibrations in the formation at the resonant frequencies using the piezoelectric devices (e.g., to shake and enlarge the existing fractures), and (5) collecting hydrocarbons released through the enlarged fractures. The method may further include flowing a proppant into the enlarged fractures to prevent them from closing or narrowing, and to aid in freeing physisorbed hydrocarbons from the underground formation.
[0024] The present invention advantageously improves the efficiency of extracting hydrocarbons from underground deposits in geological formations such as oil shale, coal beds, sandstone, and other geological formations that contain hydrocarbons. The current apparatus and method reduce or eliminate the need for hydraulic fluids in the process of fracking underground geological formations. Thus, the present invention reduces the costs associated with hydraulic fracturing, including the cost of the hydraulic fluid (e.g., the water and the additives, such as acids, buffering agents, bactericides, corrosion inhibitors, friction reducers, surfactants, gelling agents, etc.), the pumping and equipment costs for introducing the hydraulic fluids into wells, and the cost of storing the used hydraulic fluid once it is removed from wells. The present invention also reduces or eliminates the environmental impacts of hydraulic fracking resulting from the use of fracking fluids, since the present invention enables fracking underground without fracking fluids. These and other advantages of the present invention will become readily apparent from the detailed description of various embodiments below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a diagram showing the major components of a fracking system according to one embodiment of the present invention.
[0026] FIG. 2 is a diagram of a probe head containing one or more variable window piezoelectric transducers for delivering and sensing mechanical vibrations in an underground geological formation.
[0027] FIG. 3 is a schematic of an amplifier system for inducing mechanical vibrations in an array of piezoelectric devices.
[0028] FIG. 4 is a flow chart of a feedback process for determining specific ranges of resonance frequencies for an underground geological formation.
[0029] FIG. 5 is a diagram showing a process of extracting hydrocarbons from an underground geological formation.
DETAILED DESCRIPTION
[0030] Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the following embodiments, it will be understood that the descriptions are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
[0031] So that the manner in which various features of the present invention can be understood in detail, a more particular description of embodiments of the present invention, briefly summarized above, may be had by reference to various embodiments as described below and shown in the drawings. It is to be noted, however, that the appended drawings show illustrative embodiments encompassed within the scope of the present invention, and therefore, are not to be considered limiting, for the present invention includes additional embodiments.
[0032] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include”, “including”, and “includes” mean including, but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. For the sake of convenience and simplicity, the terms “connected to,” “coupled with,” “coupled to,” and “in communication with,” may be used interchangeably, but these terms are also generally given their art-recognized meanings
[0033] The invention, in its various aspects, will be explained in greater detail below with regard to exemplary embodiments.
[0034] An Exemplary Fracking System
[0035] Embodiments of the present invention generally relate to a system for inducing or enlarging fractures (fracking) in underground geological formations. In one aspect, embodiments of the present invention relate to a system that includes piezoelectric devices and is capable of determining resonant frequency ranges of fractures in underground geological formations. For example, the system is capable of producing mechanical vibrations in the resonant frequency ranges in a well to induce further fracturing of the material in the underground geological formation. In one embodiment of the system, the piezoelectric devices include ultrasonic piezoelectric transducers that are capable of detecting and producing mechanical vibrations. In another embodiment, the system further includes titanium horns coupled to the piezoelectric transducers to enhance the mechanical vibrations of or from the piezoelectric transducers.
[0036] FIG. 1 provides an illustration of an exemplary fracking system 100 . The system includes a housing 110 that may contain a pulser/receiver system capable of (1) producing electrical signals to be transmitted to an array of variable window piezoelectric transducers and (2) receiving and interpreting electrical signals from the piezoelectric transducers. The array of piezoelectric transducers can be contained in housing 170 , which organizes and protects the array of transducers 120 as they are introduced into an underground geological formation through a wellbore 160 . The piezoelectric transducers in the array may each be coupled to a horn assembly configured to amplify the vibrations of the coupled piezoelectric transducer. The horn assemblies are contained in the housing 170 along with the associated piezoelectric transducers. The piezoelectric transducers may be coupled to the pulser/receiver system by coupling cables 150 , configured to carry electrical signals between the pulser/receiver system and the piezoelectric transducers. The fracking system may also include components for introducing an innocuous proppant material (e.g., nitrogen gas, air, etc.) into the well bore to maintain fractures created by the fracking system in the underground geological formation, and a vacuum system for creating negative pressure in the wellbore to create a path of lower (e.g., least) resistance for the hydrocarbons released from the formation. For example, a reversible vacuum/pump system 140 that can both reduce pressure in the wellbore 160 and draw hydrocarbons toward the surface. Also, a storage tank 130 for the proppant (e.g., N 2 gas) may be coupled with the vacuum/pump system 140 , such that the proppant can be introduced into the wellbore 160 by the reversible vacuum/pump system 140 .
[0037] In one embodiment, the fracking system 100 may be configured to work in several wellbores simultaneously. Specifically, the fracking system may include one or more piezoelectric transducer arrays that can be introduced into one or more wellbores. Each transducer array can be introduced into a separate wellbore, and each array may contain variable window piezoelectric transducers that vary in the frequency ranges in which they can produce and detect vibrations. Additionally, the vacuum/pump system 140 may include a manifold with several wellbore couplings, each connected to a different wellbore. Thus, the vacuum/pump system 140 may be used to reduce pressure and introduce proppant in multiple wellbores simultaneously. In an alternative embodiment, the fracking system can be configured to operate on a single wellbore (e.g., 160 ).
[0038] Each variable window transducer array may include one or more probe heads that contain piezoelectric transducers. FIG. 2 shows a probe head 230 that may house one or more piezoelectric transducers and associated horn assemblies (not shown). The probe head 230 can be safely introduced into a well exposing an underground geological formation containing hydrocarbon deposits (e.g., shales, coal beds, sandstone, etc.) without damage to the piezoelectric transducers and horn assemblies therein. One or more probe heads 230 can be introduced into a single wellbore. The probe head 230 may include a tough metal housing constructed of a strong metal, such as iron, titanium, tungsten, aluminum, and alloys thereof (e.g., stainless steel), which may contain additional corrosion-resistant metals (e.g., chromium, zinc, nickel, etc.) or may be coated with corrosion-resistant metals. For instance, the probe head 230 may be made of titanium or steel (e.g., surgical grade stainless steel).
[0039] The piezoelectric transducers may be ultrasonic and polyphonic, able to produce a range of sonic to ultrasonic vibration frequencies upon the application of a voltage to the transducers from a pulser/receiver system that may be connected to the piezoelectric transducers via coupling cables 210 (or 150 , as shown in FIG. 1 ). The transducers are also able to transduce mechanical vibrations into electrical signals. Thus, the piezoelectric transducers are able to act as both sensors for sonic and ultrasonic mechanical vibrations, creating electrical current upon deformation by a mechanical vibration (the piezoelectric effect), and as oscillators for generating sonic and ultrasonic mechanical vibrations, changing molecular or crystalline structure upon the application of an electrical current (electrostriction). The piezoelectric transducers contain a piezoelectric material that behaves in this manner, such as piezoelectric ceramics and crystals. The piezoelectric transducers may include one or more piezoelectric ceramics, such as lead zirconate titanate (PZT), barium titanate (BaTiO 3 ), lead titanate (PbTiO 3 ), potassium niobate (KNbO 3 ), lithium niobate (LiNbO 3 ), lithium tantalate (LiTaO 3 ), zinc oxide (Zn 2 O 3 ), and sodium tungstate (Na 2 WO 3 ); or piezoelectric crystals, such as quartz (SiO 2 ), gallium orthophosphate (GaPO 4 ), or langasite (La 3 Ga 5 SiO 14 ). In one embodiment, the piezoelectric material is PZT.
[0040] The individual piezoelectric transducers within the probe head 230 can be tuned to different vibrational frequencies, depending on the structure of the transducer. For instance, the thickness of the piezoelectric material can be varied, in order to cover various and/or different frequency ranges. Additionally, a damping layer (e.g., a resin or metal layer, such as steel or aluminum) may be included in the transducer in order to widen the range of vibration frequencies that the transducer can detect and thus increase the transducer's sensitivity.
[0041] The piezoelectric transducers may also include other known components, such as electrodes for collecting and delivering electrical current to and from the piezoelectric material, an electrical connector between the piezoelectric transducers and the coupling cables 210 , electrical wires connecting the electrodes to the electrical connector, a housing 220 for the electrical connector between the piezoelectric transducer and the coupling cables 210 , a housing for each piezoelectric transducer within the probe head 230 , etc. Ultrasonic horns (not shown) may be coupled to each of the piezoelectric transducers in a given probe head. The ultrasonic horns vibrate with the piezoelectric transducers to increase the amplitude of the mechanical vibrations created by the piezoelectric transducer. The ultrasonic horns may comprise titanium or aluminum.
[0042] The piezoelectric transducers can be coupled to a pulser/receiver instrumentation system by coupling cables. FIG. 1 shows a housing 110 for this pulser/receiver instrumentation system coupled to a transducer array 120 by coupling cables 150 . The pulser/receiver system may include a phase-coupled inverse frequency-spectrum analyzer, an attenuator, one or more amplifiers, one or more display devices, and a quarter-wave filter assembly. The pulser/receiver instrumentation system includes a pulsing system for inducing high frequency mechanical vibrations in the piezoelectric transducers and a receiving system for electrical signals created by the detection of vibrations by the piezoelectric transducers (e.g., the phase-coupled inverse frequency-spectrum analyzer). The pulser section of the system can generate short, large amplitude electric pulses of controlled energy, which are converted into short sonic to ultrasonic pulses (e.g., about 1 kHz to about 15 MHz, about 2 kHz to about 5 MHz, about 10 kHz to about 3 kHz, or any value or range of values therein) when applied to a piezoelectric transducer. The receiver section of the system can receive and interpret the electrical signals (e.g., currents) produced by the piezoelectric transducers when they are deformed by mechanical vibrations.
[0043] The receiver section may include a frequency-spectrum analyzer capable of receiving and converting the electrical signals generated by the piezoelectric transducers into digital frequency data that can be displayed on a display device. Example, frequency spectrum analyzers that may be used include the Digital Mobile Radio Transmitter Tester, model no. MS8604A, manufactured by Anritsu, and the Agilent/HP 7000x series of spectrum analyzers.
[0044] The pulser instrumentation system may also include one or more multi-channel amplifiers for increasing the power of the signals created by the pulser for creating mechanical vibrations in the piezoelectric transducers, thereby increasing the amplitude of the mechanical vibrations of the piezoelectric transducers. The pulser and multi-channel amplifier are capable of producing signals for inducing vibrations at multiple frequencies in multiple piezoelectric transducers simultaneously. The receiver instrumentation may also include one or more multi-channel amplifiers to amplify the voltage signals produced by the piezoelectric transducers and transmitted to the receiver instrumentation by coupling cables 150 . The amplified voltage signal can be processed and converted to digital data by the frequency-spectrum analyzer and displayed as an output on the display device. The receiver and multi-channel amplifier are capable of receiving and processing electrical signals (e.g., currents or voltages) from multiple piezoelectric transducers simultaneously.
[0045] FIG. 3 is a schematic of a typical multi-channel amplifier circuit 310 , including the basic components of the amplifiers and filters. Electrical signals from one or more piezoelectric transducers 320 are received by a mixer 350 , which may combine the voltage signal of the transducer(s) 320 with a voltage from a pre-amp 340 to boost the signal. The low pass filter (LPF) 360 filters the frequency of the electrical signal from the mixer for processing in a frequency analyzer (as discussed above), and the audio amp 370 strengthens the signal from the transducer(s) 320 to enable analysis of the electrical signals produced from the piezoelectric transducer(s) 320 . These components are utilized in a feedback loop 330 that provides real-time feedback from the piezoelectric transducer(s) 320 regarding the changing resonant frequencies in the underground geological formation during the ultrasonic fracking process. The feedback loop 330 allows monitoring of the wave response of the oil shale or other material in the geological formation during the ultrasonic fracking process.
[0046] The presently described embodiments of an ultrasonic fracking system are not limiting, and the invention is intended to cover alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims. It is also understood that various embodiments described herein may be utilized in combination with any other embodiment described, without departing from the scope contained herein. In addition, embodiments of the present invention are further scalable to allow for additional clients and servers, as particular applications may require.
[0047] An Exemplary Method for Extracting Hydrocarbons Using Ultrasonic Fracking
[0048] The present invention also concerns a method of extracting hydrocarbons from underground geological formations using ultrasonic vibrations created using piezoelectric devices (e.g., a variable window transducer array, as discussed above). One or more of the piezoelectric devices can be introduced into each of one or more wellbores so that each piezoelectric device is near a hydrocarbon deposit in the underground geological formation. Subsequently, a predetermined range of mechanical vibrations can be induced in the piezoelectric device using the pulser/receiver instrumentation to induce fractures in the geological formation and release hydrocarbons therefrom.
[0049] FIG. 4 is a flowchart 400 for the general steps of ultrasonic fracking, including a feedback loop system for adjusting the frequencies used to fracture the underground geological formation. Once determined, these frequencies are used to adjust the range of ultrasonic vibrations produced from a piezoelectric device array for creating or extending fractures in the underground geological formation.
[0050] The method starts at 410 , and at 420 , a range of vibrational frequencies that are predicted to induce fracturing in the underground geological formation (e.g., oil shale, coal bed, sandstone, or other geological formation that may contain hydrocarbon deposits) are introduced by piezoelectric devices into the geological formation. Vibrations of certain frequencies are absorbed by fractures in the geological formation (resonant frequencies), and thus are attenuated when they are reflected back to the piezoelectric devices. The pulser/receiver can determine the resonant frequencies of the geological formation, based on the attenuation (lower or reduced amplitude) of the resonant frequencies that are reflected back to the piezoelectric device. At 430 , the amplitudes of the resonant frequency response are determined. Determination of the resonant frequencies at 420 and of the amplitude(s) at 430 can be repeated until the resonant frequencies of the underground formation are mapped.
[0051] At 440 , the pulser and amplifier instruments can be tuned to the resonant frequencies and amplitudes to enable further fracturing the underground geological formation. At 450 , controlled ultrasonic vibrations are induced in the piezoelectric transducers at the resonant frequencies of the fractures in the geological formation. These ultrasonic vibrations result in the shaking, fracturing, and/or enlarging of fractures in the geological formation. As mentioned above, the fracking system described above is capable of monitoring changes in the resonant frequencies of the fractures in the geological formation.
[0052] At 460 , the pulser/receiver instrumentation of the fracking system continually or intermittently monitors changes to the resonant frequencies of the fractures in the geological formation, in order to adjust the frequency of the ultrasonic pulses to the changing resonant frequencies during the fracking process (e.g., at 420 , via feedback loop 320 in FIG. 3 ). Thus, FIG. 4 shows a cyclical process, wherein frequency monitoring at 460 and analysis of the resonant frequencies at 420 and 430 are ongoing, and the frequencies delivered to the piezoelectric transducers at 440 and 450 are adjusted in response to changes detected in the resonant frequency or frequencies of the geological formation.
[0053] More specifically, the piezoelectric devices (e.g., a probe head) comprise an array of piezoelectric transducers that are each tuned to a different range of frequencies in the sonic to ultrasonic range of about 1 kHz to about 15 MHz (e.g., about 2 kHz to about 5 MHz, about 10 kHz to about 3 kHz, or any value or range of values therein), which generally covers the frequencies at which geological formations such as oil shale, coal beds, sandstone and other geological formations that contain hydrocarbons absorb vibrations. The piezoelectric transducers also absorb mechanical vibrations in their tuned range, and transduce the vibrations to electrical signals, which are transmitted back to the pulser/receiver instrumentation. Fractures in the geological formation will absorb the vibrations produced by the piezoelectric device at resonant frequencies, resulting in an attenuation of the vibrations at that resonant frequency. Thus, the piezoelectric transducers that are tuned for the frequency range that includes the resonant frequency will produce a weaker electrical signal when the vibrations are reflected by the geological formation. The attenuated signal allows pulser/receiver to identify the resonant frequency range. Subsequently, the pulser/receiver system may induce mechanical vibrations at the resonant frequencies (e.g., mechanical waves 240 and their associated nodal planes 250 , shown in FIG. 2 ) by sending an electrical current to the piezoelectric transducer(s) that is tuned for the range that includes the resonant frequencies, resulting in shaking and enlargement of the fractures. For example, FIG. 2 shows a destructive mechanical vibration 260 at the resonant frequency of a fracture in the underground formation inducing damage and enlargement of the fracture.
[0054] Prior to the fracking process, a series of relatively small diameter wellbores may form a horizontal x-y array on the ground surface. The wellbores may have variable depths, thereby creating a three-dimensional array of wellbores penetrating the underground geological formation. The varying depths of each wellbore may be used to create an optimized three-dimensional array of the piezoelectric transducers introduced into the wellbores. The three dimensional array may be predetermined. Ground penetrating radar, satellite-based imagery and geologic/seismic survey data can be used to topographically map the target geological formation for volume, density, composition, etc. After these data are acquired (given that the properties of each geological body or locale is unique), the correct x-y positions (±0.5 m 2 ) over the body can be identified. Precise depths for each bore hole can then be calculated.
[0055] Given that the general equation for a wave function is known, calculating the frequency windows needed on a Riemannian surface (the volume of the geological formation, e.g., shale body) begins by calculating the length in the time domain, then the material-dependent impedance of the ith piezoelectric transducer array by beginning, for example, with calculating the Lagrangian:
[0000] L a b (φ)=∫ a b ∥{dot over (φ)}( t )∥ dt=∫ a b (<{dot over (φ)}( t )|{dot over (φ)}( t )> γ(t) ) 1/2 dt
[0000] A Fourier Transform of this to the frequency domain would then permit determination of the frequency window for the ith transducer. As indicated above, this is merely the expectation value. Real-time data from each transducer can then optimize the pulse for the ith transducer, as it relates to the NNNth transducer (NNN=next nearest neighbor), accommodating for response time of the material surrounding each. After the body volume has been calibrated, each transducer can then be fitted with the correct titanium horn, thereby allowing each transducer to constructively, polyphonically participate in generating the disruptive manifold. Following titanium-horn installation, a total signal gain can be applied until the optimal power, power spectrum, and phase characteristics of the pulse have been achieved.
[0056] The piezoelectric devices may then be inserted into the wellbore to the point that they are within or near the underground geological formation. For example, a piezoelectric device connected to a fracking system 510 may be lowered through a wellbore 520 into geological formation 530 (see FIG. 5 ). One or more piezoelectric devices (e.g., probe heads) can be inserted into a single wellbore. Once the piezoelectric devices are sufficiently close to the geological formation 530 , the ultrasonic fracking process (as described above) can commence. In the case of vertical well bores (see, e.g., wellbore 160 in FIG. 1 ), the piezoelectric devices may be introduced into the wellbores by simply lowering them into the well. However, in the case of horizontal wells (see, e.g., wellbore 520 in FIG. 5 ), the piezoelectric devices can be inserted into the wellbores using a drilling string or a small mechanical tunnel-traversing vehicle.
[0057] As shown in FIG. 5 , during or immediately after ultrasonic fracking, vacuum or suction may be applied to the wellbore(s) 520 to reduce pressure in the opening and upper portion of the wellbore(s) 520 to draw hydrocarbons (e.g., natural gas) 550 to the surface, where it can be collected. Additionally, an innocuous proppant (e.g., N 2 gas) may be pumped into the underground geological formation in order to aid in (1) keeping the fractures in the formation (see, e.g., fractures 540 in FIG. 5 ) open and (2) de-sequestration of natural gas components (e.g., methane) that may be physisorbed to the material of the formation (e.g., oil shale, coal, sandstone, etc.). Disruption of the matrix of the geological material, followed by infusion and extraction of gases along the natural z-gradient of the formation (which results in greater local pressure at greater depths) is carried out as a cyclic, periodic process. For example, ultrasonic fracking, can be followed by infusing N 2 gas into the well bore 520 and then applying a vacuum to the wellbore 520 to draw hydrocarbons 550 (see FIG. 5 ) freed from the formation by the fracking process.
[0058] The presently described embodiments of a method of extracting one or more hydrocarbons (e.g., one or more gases at room temperature and atmospheric pressure, consisting essentially of carbon and hydrogen, such as natural gas, methane, ethane, propane, butane, etc.) from underground geological formations using ultrasonic vibrations are not limiting, and the invention is intended to cover alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.
Conclusion/Summary
[0059] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. It is also understood that various embodiments described herein may be utilized in combination with any other embodiment described, without departing from the scope contained herein. In addition, embodiments of the present invention are further scalable to allow for additional clients and servers, as particular applications may require.
[0060] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | An ultrasonic fracking system and methods of using the same to extract hydrocarbons from underground geological formations (e.g., oil shale, coal beds, etc.) are disclosed. The system includes piezoelectric devices that are used to produce ultrasonic mechanical vibrations and induce fractures in the geological formations. In one embodiment, a system for extracting underground hydrocarbons comprises a plurality of piezoelectric devices capable of producing mechanical waves sufficient to fracture oil shale and other geological formations, a system of delivery for innocuous proppants to create a path of least resistance for enhanced hydrocarbon flow, and a vacuum pump connected to the fractures created by the piezoelectric devices to assist in removing the hydrocarbons. | 4 |
This is a continuation of Ser. No. 08/404,117 filed Mar. 14, 1995, now abandoned, which was a continuation of Ser. No. 08/120,795 filed Oct. 4, 1993, now abandoned, which was a divisional of Ser. No. 07/941,807 filed Sep. 8, 1992, now U.S. Pat. No. 5,264,386.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to Read Only Memory manufacturing techniques more particularly to a method of producing high density Read Only Memory devices by making self-aligned and closely spaced polysilicon lines.
(2) Description of Related Art
Semiconductor memories have been one of the fastest growing segments of the semiconductor industry. As the density of the memory cells has increased, the cost of the devices has decreased, resulting in more and more applications.
As each new generation of memories has evolved, the chip density has roughly quadrupled. This density increase has been achieved by new and innovative cell design. Current techniques are crowding the capabilities of optical technology for alignment of masks, exposure of photoresist with light limits, and the effects of substrate surface planarity on resist exposure.
The double polysilicon read only memory (ROM) process is a known process in the art, such as shown by Y. Naruke in U.S. Pat. No. 5,002,896. However, the use of spin-on-glass in such processes is unknown.
Researchers in the integrated circuit field do use spin-on-glass plus etchback processes as shown by Chu et al U.S. Pat. No. 4,775,550; Merenda et al U.S. Pat. No. 4,826,786; Batty U.S. Pat. No. 4,894,351; and Malazgirt et al U.S. Pat. No. 4,986,878.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved method for producing Read Only Memory devices having greater integration density.
Yet another object of this invention is to provide an improved method for producing Read Only Memory devices of great density, wherein the code implantation is not limited by lithographic resolution and/or alignment accuracy.
The method of the invention produces a Read Only Memory device with cells having spaced source and drain regions in a semiconductor substrate and a plurality of closely spaced gate electrodes on the surface, spanning the distance between the source and drain. The method steps include first depositing a relatively thick oxide layer on the substrate and patterning it to provide a plurality of spaced openings between two polysilicon electrode lines where the openings define a first layer of electrode areas. Then a gate oxide is formed in the openings. A photoresist layer is deposited and patterned to selectively cover the openings and define a code implantation of the first layer of gate electrodes. An impurity is implanted in the unmasked openings, the photoresist is removed and a first relatively thick blanket layer of polycrystalline silicon is deposited, resulting in depressions over the openings in the oxide layer. Glass is deposited in the depressions using spin-on-techniques. The exposed areas of the first polycrystalline silicon layer are etched, thereby producing a first layer of gate electrodes beneath the glass areas, the glass areas are removed. The oxide layer is removed and an insulating layer is formed over the first polycrystalline layer areas. A photoresist layer is deposited, developed and patterned to selectively cover the openings between the first layer of gate electrodes that defines a code implantation for the second layer of gate electrodes. An impurity is implanted through the unmasked openings. A second blanket polycrystalline silicon layer is deposited. A glass layer is deposited in the depressions using spin-on-techniques. The exposed areas of the second polycrystalline silicon layer are etched, leaving areas which constitute a second layer of gate electrodes. An insulating layer is formed over the gate electrodes. Finally a metallurgy system is deposited and patterned to operationally interconnect the first and second layer electrodes and source and drain regions.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a preferred embodiment of the invention, and together with the objects and general description given above, and the detailed description of the preferred embodiment given below, serve to explain the principles of this invention.
FIGS. 1 through 8, and 12 through 14, schematically illustrate a series of cross-sectional representations that illustrate the process steps of a preferred embodiment of the method of the invention for forming closely spaced polysilicon conductor lines of a Read Only Memory device, and the interconnection metallurgy.
FIGS. 9 through 11 are top plan views, of sections of closely spaced conductor lines of a Read Only Memory produced by the method of the invention.
FIGS. 13 and 14 are taken on lines 13--13 and 14--14 on FIG. 11 respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing, more particularly to FIG. 1, there is illustrated a semiconductor substrate 10, preferably of monocrystalline silicon doped with a first type impurity. The substrate has spaced source and drain regions, (not shown). The source and drain regions in a Read Only Memory device, constitute bit lines, 12 shown in the overall top view FIG. 11. the substrate 10 preferably has embodied therein a P type impurity, typically boron of a concentration of between about 1E14 to 5E14 atoms/cm 3 . The source and drain regions, that is bit lines 12, are formed of regions doped with an opposite N type impurity, typically arsenic with a concentration of between about 5E18 to 5E21 atoms/cm 3 . The fabrication of the bit lines will not be described, since it is well known in the art. A thick oxide layer 14 is deposited on the surface of substrate 10 and patterned by conventional photolithographic and etching techniques to provide openings 16 between the source and drain regions that define a first layer of gate electrode area. A thin gate oxide layer 18 is formed on the surface of substrate 10 in openings 16 as shown in FIG. 2. The layer 18 preferably has a thickness of between about 100 to 300 Angstroms and is formed by thermal oxidation or chemical vapor deposition silicon oxide. A photoresist layer 20 is deposited on the substrate and patterned to selectively cover openings 16. The uncovered openings define the desired code implantation of the first layer of gate electrodes. The resist pattern does not require a precise alignment, since the openings in layer 14 act as the implant mask. A suitable impurity is then introduced into the substrate 10 through the unmasked opening 16, resulting in regions 22 as shown in FIG. 2. The impurity introduced by ion implantation techniques can be any suitable impurity of a type opposite to the background impurity in substrate 10. The impurity is preferably boron and is introduced by ion implantation using power of between about 10 to 100 KEV and between about 1E12 to 1E14 atoms/cm 2 . The silicon oxide layer 18 can then be formed by thermal oxidation or chemical vapor deposition methods.
As shown in FIG. 3, after the photoresist layer 20 is removed, a first polycrystalline silicon layer 24 is deposited. The layer 24 is deposited using well known techniques to a thickness in the range of about 1000 to 6000 Angstroms, preferably on the order of 2000 to 4000 Angstroms. As shown, the layer 24 conforms to the surface of layer 14, resulting in depressions 26, where the layer drops down into opening 16.
Spin-on-glass 28 is then deposited in the depressions 26, using spin-on techniques. A single or even a double coating of a siloxane, such as Allied Signal 211 is applied. Alternatively, a silicate type spin-on-glass coating could be used. The spin-on-glass material suspended in the vehicle or solvent is deposited onto the semiconductor wafer surface and uniformly spread thereover by the action of spinning the wafer, for example, at 3500 revolutions per minute. The material fills the indentations in the integrated circuit wafer surface, that is planarization.
Most of the vehicle or solvent is then driven off by a low temperature baking step. The wafer is heated to for example 80° C., 150° C., and 250° C. Each heating duration is one to two minutes. The total thickness of the spin-on-glass material is sufficient to fill the depressions to a thickness of at least the thickness of layer 14.
A curing step in a nitrogen atmosphere densifies the spin-on-glass layer by converting the organic material, at least in part to a silicon oxide structure. The curing process typically used a 50 minute stabilization time followed by a 15 minute rap-up from 370° C. to 425° C. The curing time is about 60 minutes.
The spin-on-glass layer 28 is blanket anisotropically plasma etched back using fluorocarbon gases as are known in the art until the spin-on-glass layer 28 is left only in the depressions as seen in FIG. 3. The selectivity between the spin-on-glass layer 28 and the layer 24 is very good using both etching techniques.
As shown in FIG. 4, the exposed portions of polysilicon layer 24, i.e. the areas not covered by spin-on-glass layer 28, are removed by blanket plasma etching, resulting in the forming of a plurality of gate electrodes, i.e. a first layer of gate electrodes. The sidewalls of the resulting gate electrodes are vertical, or substantially vertical, when layer 24 is anisotropically etched, as is well known.
Then, as shown in FIG. 5, the spin-on-glass layer portions 28 are removed, preferably by either a reactive ion etching process with CHF 3 or by wet etching using hydrofluoric acid with or without buffering. The layer 14 is also removed during this etching process, and an insulating layer 32 is preferably formed by initially thermally oxidizing the electrode layer 30. Then a thicker layer 34, such as silicon oxide is deposited by chemical vapor deposition techniques, such as atmospheric pressure, low pressure or plasma enhanced chemical vapor deposition. The layer 34 is then etched back to expose the substrate between the electrodes 30, thereby forming spacer walls 34.
As shown in FIG. 6, a gate oxide 36 is formed on the surface of substrate 10 between gate electrodes 30. A photoresist layer 38 is deposited and patterned to selectively cover the openings 40 between electrodes 30, to define the desired code implant for the second layer of gate electrodes to be formed between the first layer of gate electrodes 30. A suitable impurity is introduced into the substrate 10 through the unmasked openings 40, resulting in regions 42. The introduction of impurities is similar to the introduction of impurities for forming regions 22.
As shown in FIG. 7, after the photoresist layer 38 is removed, a second blanket polycrystalline silicon layer 4 is deposited in the same manner as layer 24, as described previously. Spin-on-glass layer 46 is deposited in depressions 45 in the same manner as described previously in regard to spin-on-glass 28. As shown in FIG. 8, the exposed portions of layer 4, not covered by spin-on-glass layer 46, are blanket plasma etched a described previously with layer 24, leaving gate electrodes 48, i.e. a second layer of gate electrodes positioned between gate electrodes 30. The spin-on-glass layer 46 is removed as described previously with spin-on-glass layers 28, and an insulating layer 50 deposited over the entire surface of the substrate, as shown in FIG. 12. The layer 50 is preferably a layer of borophosphosilicate glass, with an average thickness in the range of about 2000 to 15000 Angstroms, most preferably of the thickness of 4000 to 8000 Angstroms. The layer 50 can be deposited by chemical vapor deposition techniques, such as atmospheric pressure, low pressure or plasma enhanced chemical vapor deposition. The structure is heated from 850° to 950° C. during the deposition of layer 50 which acts to densify and complete the curing of the spin-on-glass layers of the structure.
Subsequently, the interconnection metallurgy system is fabricated. A contact opening 52 is made through layer 50 to expose region 11 (BN+), and a metallurgy stripe 54 formed using convention photolithographic and etching techniques. The same technique is used to form a contact 56 to gate electrode 48, which is a bit line, as shown in FIG. 13, and a metallurgy contact 58 made to gate electrode 30, as shown in FIG. 14.
FIG. 11 presents the general layout of the cell structure fabricated by the method of the invention. The various elements have the same numbering as the elements shown in FIG. 1 through 9 and 12 and 14. FIGS. 9 and 10 show portions of the FIG. 11. FIG. 9 at 11 shows the BN+ implanted region or source/drain regions and metal contact 58 thereto.
The advantages of this invention is the ability to produce a double density polysilicon line structure for a given integrated circuit chip area, because of the novel method. This is clearly seen in FIG. 8 where polysilicon I is 30 and polysilicon II is 48. Also, the first code implant regions 22 and second code implant 42 are both deposited with self-alignment.
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art, that various changes in form and details may be made without departing from the spirit and scope of the invention. | A read-only-memory having a plurality of very narrow, closely spaced gate electrodes spanning the distance between source and drain regions. The gate electrodes consist of first and second alternating polycrystalline silicon lines having vertical sidewalls. The first lines have tapered sidewall spacers. The second lines are entirely contained between the first lines without overlap of the first lines. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hair drying apparatus of the type that are designed to be hand held, and which produce a flow of hot air without requiring the dryer to be connected to an external A/C power source to operate. In particular, the present invention is directed to improvements in such handheld cordless hair dryers which will serve to make a hair dryer produced in accordance with the invention lighter, safer, more compact, and more convenient to use than previously existing hair dryers of this type.
2. Description of Related Art
The overwhelming majority of handheld hair dryers in use today are of the type which must be connected to an external A/C power source via an electrical connector cord. The electrical power derived from the A/C power source is used to heat electrical heating coils, across which a flow of air is directed by a blower. Because such hair dryers have a power requirement of as much as 600 to 1200 watts, they are not suitably adaptable to "cordless" usage because it is not feasible to meet this power requirement via a D.C. power supply (such as storage batteries) in a device intended to be held comfortably in one hand.
Therefore, to obtain a handheld hair dryer that does not have its portability tied to the length of its electrical power cord, handheld hair dryers have been developed which use a gas or liquid fueled combustion device to heat the flow of drying air. One example of a cordless handheld hot air hair dryer of this type is that of Bourdeau U.S. Pat. No. 4,635,382. The dryer of the Bourdeau patent is provided with a fuel reservoir for storing a vaporizable fuel in a liquid state and the fuel is vaporized and combusted within a heating chamber disposed in a nozzle portion of the dryer. The heating air flow is generated by a battery powered motor that is used to drive the fan, and a single manually operated control means is used to control both the amount of current applied to the fan motor and to adjust the flow of fuel to the combustion device. This manually operated control means utilizes a slide-type actuator to move a rheostat for the fan motor and a valve of a fuel supply line.
However, the hair dryer of the above-noted patent provides no means for preventing the combustion fumes from being mixed with and discharging along with the heating air, nor are there are safeguards to protect against overheating conditions or failure of the combustion device to ignite. Likewise, the fact that the dryer contains a reservoir of liquid fuel poses a significant safety hazard, as does the fact that, once the actuating member of the manually operative control means is shifted into its "on" position, it remains in its operational state, even if the user should not be holding the device at the time, having put it down without turning it off. Finally, the heater of the device employs asbestos which is hazardous, and the unit incorporates a recharging transformer in the handle which both adds weight to the unit as well as placing an electrical component close to the reservoir of ignitable fluid.
Another patent disclosing a cordless handheld hair drying apparatus is that of the Raccah, et al. U.S. Pat. No. 4,555,232. The Raccah, et al. patent discloses several different dryer constructions. In accordance with aspects of each of these embodiments, various of the above-noted deficiencies are overcome. For example, in one embodiment, instead of utilizing a liquid fuel reservoir, a gas-containing fuel cartridge is placed within the handle portion of the dryer. Additionally, a flame detector is provided to shut off the gas supply in the event of a flame failure and a temperature sensing means is provided in another embodiment whereby a valve progressively closes as the temperature in the vicinity of the burner increases, thereby decreasing the supply of fuel to the burner and acting to prevent a temperature overload. Furthermore, while this patent discloses that steps may be taken to prevent combustion products from entering the air flow, via ducts or shrouds, no particular arrangement for achieving such a result is described. Still further, all of the embodiments disclosed in the Raccah, et al. patent are relatively complex in construction and they fail to provide an arrangement whereby heat output can be maximized without overheating the nozzle body portion of the dryer.
Thus, there is still a need for a compact, cordless handheld hair dryer which can be produced in a simple and, therefore, less costly manner, yet still maximizes safety and heat output efficiency.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide a compact, cordless hair dryer which will overcome the above-noted deficiencies of the prior art by being simple to construct and easy to use, while being a safe and highly efficient heat producing device.
It is a particular object of the present invention to provide a handheld cordless hair dryer wherein maximum heat can be transferred from a burner to an airflow via the use of a heat exchanger comprised of inner and outer ducts having heat conductive vanes extending along and between the ducts, wherein a combustion device is mounted in one end of the inner duct and an opposite end of the inner duct opens exteriorly through a peripheral wall of the nozzle body portion so that the inner duct comprises a combustion tube and exhaust duct for the gas combustion device, and air may be circulated through the space between the inner and outer ducts in a highly effective heat transfer relationship with respect to the combustion flame and exhaust within the inner duct, yet the heat exchanger can be thermally shielded relative to the peripheral wall of the nozzle body itself.
Yet another object in accordance with the present invention is to provide safety shutoff means which will terminate the flow of gas to the combustion device whenever temperature levels in the heat exchanger exceed a predetermined safety limit and whenever a flame is not present after triggering of the igniter of the combustion device.
Another object of the present invention is to provide a manually operable actuation means for activating the gas fuel supply for the combustion device of the inventive dryer that comprises a single manually shiftable switch means which may be operated by a simple depression of a push-button by a finger of a user's hand grasping a handle body portion of the dryer, so as to commence a flow of gas to the combustion device followed by triggering of the ignition means therefor and activating of fan means for the heating airflow, which will automatically return to a released deactivating position when manually applied pressure is removed therefrom, and wherein lock means is provided to prevent inadvertent shifting of the switch means into an operative position.
The above objects and others are achieved in accordance with a preferred embodiment of the present invention by providing the dryer with a handholdable body having a handle body portion and a nozzle body portion mounted to a top end of the handle body portion. Battery powered fan means are provided for drawing a flow of air into the nozzle body portion and for directing the flow of air along a path through the nozzle body portion and out of a discharge opening located in an outlet end of the nozzle body portion. This battery powered fan means can be conveniently mounted at an opposite end of the nozzle body portion circumferentially flanked in part by a rechargeable D.C. power supply. A heat exchanger is disposed in the path of air directed through the nozzle body portion and a gas combustion device is disposed in the nozzle body portion in heat exchange relationship with the airflow produced by the fan means via the heat exchanger.
A supply of gas fuel is provided via a self-contained supply of gas received in a gas container receiving space in the handle body portion. Also located in the handle body portion is a manually operable actuation means for activating a supply of the gas fuel to the gas combustion device for igniting of the gas combustion device via an ignition means, and for turning on of the fan means.
In accordance with a significant aspect of the present invention, a highly efficient transference of heat from the combustion device to the airflow is produced by designing the heat exchanger of a heat conductive inner duct, an outer duct, and heat conductive vanes extending along and between the inner and outer ducts in heat exchange relationship to the airflow, and by having the inner duct serve as both a combustion tube and an exhaust duct for the gas combustion device. The gas combustion device is located at one end of the inner duct and the other end opens exteriorly through a peripheral wall of the nozzle body portion. This construction is particularly effective when the combustion device is located at the outlet end of the heat exchanger and the exhaust outlet end of the inner duct is disposed in proximity to the inlet end of the heat exchanger. This construction also offers the benefits of preventing combustion products from entering into the heating airflow and by providing a space between the inner surface of the peripheral wall of the nozzle body portion and the outer duct which can be used to shield the peripheral wall from the high temperatures existing within the heat exchanger.
In accordance with another aspect of the present invention, a simple and compact construction for enabling a single manually shiftable switch means to be operated by a hand of a user grasping the handle body portion is provided for commencing a flow of gas to the gas combustion device followed by triggering of the ignition means and activating of the fan means in a manner which provides a high degree of safety. In particular, the switch means is caused to automatically return to its released position deactivating the apparatus upon removal of manually applied pressure therefrom. Advantageously, the manually shiftable switch means is a push-button actuator mounted for radial reciprocation within the handle body portion and the means for automatically returning the manually shiftable switch means to its released position is a spring acting between the push-button actuator and an inner wall of the handle body portion.
Furthermore, the compactness of the arrangement is facilitated by disposing this switch means between a first reciprocable operator for controlling the flow of gas and a second reciprocable operator for controlling triggering of the ignition means and activating of the fan means. In thi manner, a cam and follower relationship can be established between the push-button actuator and the operators so that the operators can be displaced in a controlled sequence in opposite directions, as the push-button is pressed, such as by an interaction between rollers carried by the push-button and respective, aligned ramp means provided on the operators.
These and other objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially exploded rear perspective view of a cordless hair dryer in accordance with a preferred embodiment of the present invention;
FIG. 2 is a frontal, partially exploded, perspective view of the hair dryer of FIG. 1;
FIG. 3 is a cross-sectional view through the nozzle body portion of the preferred embodiment hair dryer of the present invention along line III--III of FIG. 2;
FIG. 4 is a horizontal sectional view through the nozzle body portion taken along line IV-IV of FIG. 2; and
FIG. 5 is a partial, vertical sectional view through the handle body portion of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 1 and 2, a preferred embodiment of a handheld cordless hair dryer in accordance with the present invention is illustrated and designated, generally, by the reference numeral 1. The handholdable body of the cordless hair dryer 1 is comprised of a handle body portion 3 and a nozzle body portion 5 that is mounted to a top end of the handle body portion 3.
A battery powered fan means for drawing a flow of air into the nozzle body portion 5 and for directing the flow of air along a path through the nozzle body portion 5 and out of discharge opening 6 at an outlet end of the nozzle body portion 5 is comprised of the components shown most clearly at the right-hand side of the nozzle body 5 as illustrated in FIG. 1. In particular, the battery powered fan means has a fan unit 7 formed of a fan motor 9 and a fan impeller 11 mounted to the output shaft of the motor 9. The fan unit 7 is powered by batteries, preferably rechargeable nickel-cadmium batteries, which are contained in a battery case 13, shown compactly arranged, peripherally surrounding a lower portion of the rear end of the nozzle body portion 5.
The batteries in case 13 can be recharged from a separate, conventional battery charger by plugging the charger into a recharging jack 15. In this regard, it is noted that because of the weight that would be associated with the transformer of a battery charging unit, incorporating a recharger into the body of the dryer itself would make the hair dryer 1 too heavy. To allow adjustment of the fan speed, a fan speed controller 17, in the form of a conventional multiposition, slide-type rheostat may be provided. In order to securely hold the fan unit 7 in place within the nozzle body portion, while enabling air to be drawn in from the inlet end 19 of the nozzle body portion 5, around the fan unit 7 and on toward the discharge opening 6, a fan holder 21 is used that is formed of a sleeve 23 having a plurality of axially extending support ribs 25. While the described battery powered fan means is preferred, it should be appreciated that, by enlarging the nozzle body portion 3 and displacing it rearwardly relative to the position shown, a vertically oriented fan unit may be utilized having a radially discharging impeller within the nozzle body portion 5 and with the motor disposed below it within the handle body portion.
Disposed in the path of air directed through the nozzle body portion 5, from the fan unit 7 to the discharge opening 6, is a heat exchanger designated generally by the reference numeral 27 in FIGS. 2 and 3. In accordance with the illustrated preferred embodiment, the heat exchanger 27 is comprised of a heat conductive inner duct 29 formed of metal, and an outer duct 31 which is also preferably formed of heat conductive metal. Outer duct 31 can, alternatively, be formed of a nonconductive material provided with a heat conductive inner lining in order to minimize transference of heat radially outwardly from the heat exchanger 27 to the peripheral wall 33 of the nozzle body portion 5. In order to further minimize heat loss from the heat exchanger 27 to the peripheral wall 33 (both for maximizing heating efficiency and for preventing the peripheral wall 33 from becoming too hot), internal standoffs 35 are provided to support the heat exchanger 27 in spaced relationship to an inner surface 37 of peripheral wall 33 of the nozzle body portion 5. In this manner, an insulating space 39 is created between the heat exchanger 27 and the peripheral wall 33. Insulating space 39 may be a "dead air" space that is closed, for example, at one end by a nozzle piece 41, or it may be filled with a glass wool type insulating material 39, or it may be open to permit a small portion of the airflow from the fan unit 7 to pass therethrough.
Heat exchanger 27 serves to transfer heat to the airflow passing through it from a flame and exhaust gases produced by a gas combustion device 43. The gas combustion device may be a simple conventional gas burner unit which may draw in combustion air at an entrance end of the inner duct within which it is mounted, or it may be of a known catalytic combustion type (for example, one wherein platinum is used to combust the gas fuel, which in either case may be a gas such as butane). If a typical gas burner is utilized, then the ignition means 45 will comprise a pair of electrodes between which an arc can be produced from current supplied through ignition wires 47, in a manner to be described in greater detail later on. On the other hand, if a catalytic combustion device is utilized, the ignition means 45 will be in the form of a heating wire that is electrically heated via the ignition wires 47.
In order to maximize the amount of heat that can be extracted, from the results of the combustion process performed by device 43, and transferred to the airflow passing through the heat exchanger 27, the inner duct 29 of the heat exchanger 27 serves as a combustion tube and exhaust duct for the gas combustion device 43 and is disposed so that its intake end is located in proximity to an outlet end of the heat exchanger 27, and its opposite, discharge end is disposed in proximity to an inlet end of the heat exchanger 27, and by running it from the bottom side of the peripheral wall at the outlet end of the heat exchanger to a top side of the peripheral wall 33 at the inlet end of the heat exchanger.
The described arrangement not only maximizes the length of the combustion tube/exhaust duct from which heat may be transferred to the heating airflow through the heat exchanger 27, but also serves to ensure that the temperature of the exhaust gases is as low as possible by the time they are discharged from the nozzle body portion via the exhaust outlet 49 in peripheral wall 33. That is, since the airflow from the fan unit 7 is substantially unheated at the inlet end of the heat exchanger 27, it will not produce a reheating of exhaust gases in the discharge end of the inner duct 29 and will be best able to extract heat therefrom. Furthermore, since the temperature of the airflow will never reach that existing within the combustion zone at the intake end of the inner duct 29, the heating airflow will be able to extract heat generated by the combustion process along the full length of the heat exchanger despite the progressive increase in temperature thereof. This is in contrast to the situation that would result if the combustion device 43 were to be disposed at the intake end of the heat exchanger 27 and the exhaust gas outlet at the outlet end of the heat exchanger, because in such an arrangement the heating airflow may reach a temperature high enough to exceed that of the exhaust gases so as to undesirably start a transference of heat back from the heating airflow to the exhaust gases, reheating them so that they may be too hot when they are discharged from the dryer.
To further facilitate the extraction of heat from the flame and exhaust gases within inner duct 29, a cruciform arrangement of heat conductive metal vanes 51 may be provided extending within the inner duct 29. Similarly, a cruciform-shaped array of heat conductive vanes 53 are provided extending between the periphery of the inner duct 29 and the outer duct 31 of the heat exchanger 27. These vanes 53 not only facilitate transference of heat to the airflow passing through the heat exchanger between the inner and outer ducts 29, 31, but also serve as a means for supporting the inner duct 29 within the outer duct 31.
The manually operable actuation means by which a supply of gas fuel is delivered to the combustion device, ignition of the combustion device and operation of the fan means is activated, will now be described.
The manually operable actuation means of the present invention is designed so that by depressing a single manually shiftable switch means positioned on the handle body portion 3, a finger of a user's hand grasping the handle body portion 3 can, in a single operation, commence a flow of gas to the combustion device 43, trigger ignition of the ignition means 45, and, thereafter, turn on the fan unit 7. In the illustrated embodiment, the single manually shiftable switch means comprises a push-button 55 situated on a front side of the handle body portion 3 at a location for operation by the indexing finger of a user's hand. However, it should be appreciated that it could be located on the opposite side of the handle body portion 3, for operation by the thumb of a user's hand, instead, without in any way changing any other aspects of the invention.
Furthermore, in order to prevent the pushbutton 55 from inadvertently being depressed from its illustrated released position of FIG. 1 into its shifted actuating position (illustrated in FIG. 5), such as by contact with objects packed with it inside a suitcase, a locking means is provided. For example, such locking means may be in the form of a plate 57, that is slidable on the peripheral surface of the handle body portion 3 under a flange plate 59, and which has projecting tab portions 57a which may engage in notches 61 (only one of which is represented in FIGS. 2 and 5) when the push-button 55 is in its released position and the plate 57 is slid toward the push-button from the position illustrated. Of course, it should be appreciated that any other known type of push-button locking device may be utilized. Additionally, it is noted that the push-button 55 is automatically returned into its released position by a spring biasing arrangement 63, such as that using a coil spring shown in FIG. 5.
In order for the push-button switch means 55 to commence a flow of gas to the combustion device 45, produce triggering of the ignition means 45, and activate the fan unit 7 in a sequential manner, the manually shiftable switch means formed by push-button 55 is positioned between a first reciprocable operator 65 for controlling the flow of gas from a gas supply cartridge 67 (FIGS. 1 and 5) and a second reciprocable operator 69 for controlling triggering of the ignition means 45 and activating of the fan unit 7. When the push-button 55 is depressed, the operating members 65, 69 are "wedged" apart by a cam and follower means acting between the push-button 55 and the first and second operators 65, 69.
The cam and follower means comprises a plurality of rollers 71 carried by a roller shaft 73 that is supported in pin holes 75 at opposite sides of the push-button 55. These rollers coact with ramp means in the form of a pair of ramps 77, positioned on top of the first operator 65, and a ramp 79 formed on the underside of second operator 69. Each of the ramps 77, 79 is aligned with a respective one of the rollers 71 and has an inclined surface along which the rollers 71 travel during shifting of the push-button 55. In this way, as the push-button 55 is depressed, the rollers 71 travel along the inclined surfaces in a manner causing the operators 65, 69 to be axially displaced lengthwise within the body portion 3, in opposite directions away from the push-button 55.
The first operator 65, itself, is in the form of a piston that is slidably received within the body portion 3. An axially extending through-passage 81 extends centrally from the bottom side to the top side thereof. The underside is provided with a first counterbore 83 within which an O-ring seal 85 is disposed, and with a second counterbore which seats upon the discharge nozzle of cartridge 67, when the cartridge is inserted into the open bottom end of nozzle body portion 3 and the end cap 89 reattached. Similarly, the topside of the piston forming the operator 67 is provided with a pair of counterbores between the ramps 77. Fixed in place within the innermost topside counterbore is a fuel line coupling 91. A fuel supply line 93 fits snugly upon the coupling 91 within the outer counterbore 95. Thus, when the piston 65 is forced downwardly, as a result of the interaction between the rollers 71 and ramps 77, due to the push-button 55 being depressed, the cartridge 67 is actuated to release a supply of butane gas into the fuel line 93.
Inasmuch as one form of the cartridge 67 is a commercially available product, such as that sold under the trademark "Thermacell" by the Schwabel Corporation of Cambridge, Mass., no detailed description is necessary as to the discharge manner of operation of the cartridge, itself. It is also noted that, to cover the unlikely possibility that some butane gas may be released into the handle body portion during installation of the cartridge or otherwise, vent openings 97 may be provided through the wall of the handle body portion near the lower end thereof, as shown in FIGS. 1 and 2.
Other commercially available butane cartridges may be used as the cartridge 67. For example, the cartridge 67 may be a refillable cartridge which screws into the handle 3 and which may be refilled by turning the blower into an inverted position with the handle above the nozzle. For cartridges which do not incorporate a vaporizer within the cartridge, an exernal vaporizer may be included in the fuel supply line 93 as indicated in broken lines at 96.
The second operator 69 is in the form of a shuttle member that is axially, slidably received within an interior space 99 of a shuttle casing 101. The ramp 79 is biased downwardly into contact with a roller 71 carried by the push-button 55 by a return spring 103 that is disposed in interior space 99, between opposed wall surfaces of the shuttle 69 and shuttle casing 101. A receiving space 105 is provided for an ignition triggering means 107 that creates a voltage which is applied to the ignition means 45 of the combustion device 43 when the shuttle 69 is displaced upwardly a sufficient degree to bring the ignition triggering means 107 into engagement within an adjustable striking member, such as a set screw 109. Set screw 109 is threaded through the top wall of the shuttle casing 101 at a location that is aligned with the triggering means 107. Thus, by threading the set screw 109 in and out of the casing 101, the point at which ignition is triggered can be adjusted. In this regard, it is noted that the triggering means can be of any conventional design, such as igniters of the type which utilize a plunger-activated piezoelectric ceramic element. For activating the fan unit 7, a fan activation switch of a type which turns on when a plunger member is pushed in and automatically turns off when pressure is no longer applied to the plunger, is mounted extending through the top wall of the shuttle casing 101 in a manner such that its actuating plunger is aligned in opposition to a fan activation adjustment set screw 113 that is adjustably threaded into the top of the shuttle member 69.
Thus, it should be apparent that, by appropriate selection of the relative slopes of the ramps 77, 79 and adjustment of the set screws 109, 113, an activation sequence can be properly coordinated so that first the supply of gas from the cartridge 67 to the combustion device 43 is commenced, and then, once the fuel has had time to reach the combustion device, ignition is triggered, followed, after a sufficient time for ignition to be achieved, by turning on of the fan unit 7. Furthermore, as soon as the push-button 55 has been released, the spring arrangement 63 causes the push-button 55 to be displaced from its activating position to its released position. As a result, operation of all components is terminated as the first and second operators 65, 69 are returned towards each other, back to their original, inactive positions, by the action of cartridge 67 and return spring 103, respectively. In this way, no harm can come if, for example, the dryer 1 is put down in an operating mode (for example, should the user have to rush to answer the telephone) and, thereafter, should forget that it has been left on.
In addition to the above safety precaution, the cordless hair dryer 1 has been provided with means to prevent potentially hazardous conditions from occurring during operation with push-button 55 depressed. In particular, safety shutoff means is provided in the form of an electrically operated gas valve 115 (FIG. 2) which is provided in the gas line 93. Gas valve 115 may be of a type that is normally open, but which is closed in response to receipt of an electrical signal. In this way, by providing a temperature sensing means on the heat exchanger 27, in the form of a switch which will produce an electrical signal when a predetermined temperature limit is exceeded, should potentially hazardous temperature levels be reached in the heat exchanger, i.e., temperatures which could result in damage to the dryer or injury to the user, a signal will be generated by the temperature sensor 117 which will cause the supply of gas fuel to the combustion device 43 to be reduced or completely shut off.
Similarly, a flame detector 119 of conventional design can be disposed in the inner duct 29 at a flame zone of the combustion device 43. Flame detector 119 serves to terminate the supply of gas to the combustion device should a flame not be produced within a predetermined time interval (such as 3 seconds) after triggering of the ignition means. In this way, a potentially explosive quantity of gas cannot accumulate in the duct between the time that the push-button 55 is pressed and the time that the user discovers that heating is not occurring and attempts to restart the device by releasing and redepressing the push-button 55. However, to permit gas to be delivered through valve 115 to the combustion device 43 when push-button 55 is initially depressed, a timing switch, activated upon depressing of the push-button 55, can be connected between the flame detector 119 and the gas valve 115 to prevent a signal from flame detector 119 being delivered to the gas valve 115 until the above-noted period of time sufficient to achieve ignition has elapsed. Of course, other equivalent control techniques, known per se, will be apparent to those of ordinary skill in the art, and may be used instead.
From the foregoing, it should be appreciated that the present invention provides a cordless hair dryer which is able to very efficiently produce a flow of high temperature air, yet effectively prevents potentially hazardous high temperature exhausts from being discharged and prevents transmission of high temperatures to the peripheral wall of the nozzle body portion itself. Furthermore, the manner in which the actuation components are constructed and arranged within the handle body portion enables a very compact construction to be achieved in a manner that is inexpensive to manufacture, while still being extremely simple to use by the press of a single finger of a hand holding the hair dryer. Furthermore, it should also be clear that the present invention is adaptable to a wide range of hair dryer designs which will not only be useful around the home, but will allow the device to be utilized where no source of A/C power is available, such as on camping trips, in automobiles, etc. The hair dryer is much safer than conventional electrical hair dryers which can be accidentally dropped in a sink full of water when in use. The present unit cannot cause electrical shock and cannot be left in an operating mode.
While we have shown and described a single embodiment in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and we, therefore, do not wish to be limited to the details shown and described herein, but intended to cover all such changes and modifications as are encompassed by the scope of the appended claims. | A handheld cordless hair dryer utilizes a battery powered fan for directing a flow of air through a nozzle body portion within which a heat exchanger is disposed in heat exchange relationship with respect to both the airflow and heat generated by a gas combustion device. To provide a highly efficient transference of heat from the gas combustion device to the airflow, while avoiding high temperature conditions in exhaust gases discharged or at the peripheral wall of the nozzle body portion, the heat exchanger is comprised of a heat conductive inner duct and an outer duct between which conductive vanes extend, the outer duct being in spaced relationship with respect to an inner surface of the peripheral wall of the nozzle body portion and the inner duct serving as both a combustion tube and an exhaust duct for the gas combustion device. To provide a simple and safe operation, a single manually shiftable switch is actuatable in response to manually applied pressure exerted by the hand of a user grasping the handle body portion, the switch means being designed to automatically return to a deactivating position upon removal of the manually applied pressure, and a locking arrangement being provided to prevent inadvertent shifting of the switch into its activating position. Furthermore, a safety shutoff valve arrangement are provided for terminating the flow of gas to the gas combustion device when unsafe temperature levels result in the heat exchanger and whenever a flame is not produced or is extinguished after being produced. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally concerns holders, removably mountable to ladders and step ladders, of paint cans and tools and like implements for use by painters and electricians and other individuals when, in the course of their work, these persons stand on ladders and step ladders. The present invention is directed at a convenient means for carrying and organizing and holding various work supplies and work implements in proximity to work conducted by a tradesman from a ladder or step ladder.
The present invention particularly concerns flexible tool and paint pail holders that removably mount atop step ladders so that a workman (i) may conveniently transport tools and supplies, including paint, to the ladder within a holder, (ii) may easily and securely mount a holder to the ladder, (iii) may have convenient access to tools and supplies held within the holder while standing on the ladder, and (iv) may at any time replenish any tools or supplies within the holder with minimum disruption.
2. Description of the Prior Art
Ladders have been employed since their inception to place a worker into proximity to an elevated surface or article that needs be physically manipulated, such as for purposes of painting, plumbing, wiring etc. Of the several well-known styles of ladders available, a step-ladder consists of (i) a fixed ladder member which is joined to (ii) a supporting member having dimensions and construction similar to that of the fixed ladder portion but designed primarily as a support. The (i) fixed ladder member and the (ii) supporting member are joined by a suitable hinge, transverse to the long axis of both members, such that the ladder member and support member may be opened with respect to one another, forming thereby an essentially A-frame configuration. A top step is usually provided at the external apex of the “A”.
This step ladder provides the ability to elevate ones-self in the absence of a fence, wall or other structure normally required when using a fixed ladder alone. It is to users of the step-ladder which the present invention is directed, but the principles of the present invention, particularly in the aspect of its paint pail pouch, are anticipated to be useful on the other types of ladders as well, and it would be unnecessarily restrictive to view the particular application of the present invention to step ladders as is taught within this specification as being delimitive of the invention.
One of the problems individuals who find themselves on ladders regularly encounter is that they must prevent themselves from falling from the ladder while performing the task at hand. Additionally, a variety of hand-implements are often required to carry out various tasks to their completion. From a statistical standpoint, the probability of an individual having a mishap varies directly as the number of times an individual goes up and down from the ladder in connection with a job. Therefore, if it were possible to minimize the number of up-and-down trips an individual was required to make in the normal course of carrying out tasks from a ladder, then the probability of a mishap could be accordingly minimized.
One way to minimize the number of up-and-down trips required to carry out a task is to provide every tool and/or material needed for a given job in close proximity to the location atop the ladder where the worker is situated. However, while the prior art contains many different types of devices aimed at this end, none has been successful in design both so as to be (i) ergonomically effective, and (ii) sufficiently cost-effective of manufacture so as to be widely adopted.
A review of some of the criteria that a ladder, or step-ladder, tool holder would desirably realize is useful. Flexible and removable, fabric-type, holders seemingly offer a large holding capacity, but these holders tend not to maintain a defined volume, and are subject to collapsing inward. This is adverse in that even a loaded holder should be capable of being slipped into position on or atop a step ladder by use of but one hand, making that the holder must maintain itself open and ready to receive mounting upon the step ladder. Moreover, a holder removed from a ladder mounting should not slump or collapse so completely that held objects such as tools become dislodged.
An optimally commodious tool holder would seemingly best make good use of every one of the five exterior surfaces of defined by the volume in the shape of a truncated four-sided pyramid at the top of a step ladder. Use of the substantially flat top surface to the step ladder is immediately problematic. Should this surface be left unencumbered so that it may be stood upon, or should it be adapted for holding objects or things?
Finally, the retention of paint cans and pails both large and small is potentially challenging to flexible fabric holders, especially as these containers and their contents would desirably be held level.
Attempts to solve these challenges are shown in various issued United States patents.
U.S. Pat. No. 6,116,419 to Campagna, et al. for a LADDER POUCH shows an elongate, flexible sheet having a first end, a midpoint, a second end, a first side, and a second side. A first engagement structure, such as hook and pile fastening material, is located on the first side of the elongate, flexible sheet between the midpoint and the first end. A second engagement structure, complimentary with the first engagement structure, is located on the second side of the sheet proximate its second end. Multiple pockets are disposed on or integral with the first side of the sheet. The pockets can be open-mouthed or include covering flaps.
U.S. Pat. No. 5,988,383 to Armstrong for a LADDER SADDLE DEVICE shows a holder device containing various work implements designed for use by workers who regularly use ladders. The device holds the implements in such fashion as to be ergonomically accessible while maintaining a reduced center of gravity and hence increased stability of the ladder/device combination as a whole. Use of this device is claimed to increase safety while being cost-effective enough in its construction to be readily employed by workers in various crafts and professions.
U.S. Pat. No. 5,971,101 to Taggart for an ADAPTABLE CARRIER APPARATUS shows a tool and material carrier adaptable for use on a variety of platforms such as four and three legged step ladders, extension ladders, universal or hinged ladders, platform ladders, scaffolding and the like. The carrier is made of a foldable body which conforms to various platform deigns. A multiple strap system having quick lock and release connectors secures the carrier to the various platforms. The front of the body includes a multi-tiered system of pouches and holders for tools and materials. The rear of the body includes additional pouches or holders. The carrier includes a holster for gun shaped tools. An electric cord holder provided with or separately from the carrier holds an electric cord close to the working elevation of the platform. The electric cord holder includes a foldable strap having two portions which are mated when the strap is folded to form an opening smaller than the head of an electric cord to secure the electric cord between the two portions. Modular, task specific, attachments to the carrier provide additional versatility such as an attachable mud pan and mud knife holder or an attachable butane torch holder.
U.S. Pat. No. 5,749,437 to Weller for a FREE-STANDING LADDER SUPPORTED TOOL HOLDER concerns a non-obstructive tool holder which holds tools on a free-standing ladder, e.g. a step-ladder. The tool holder is configured so avoid obstruction of normal use of the free-standing ladder. The tool holder has a skirt including a front side sheet, a rear side sheet, a left side sheet, and a right side sheet connected together at sides thereof to form a generally tubular structure having a top opening and a bottom opening. The skirt narrows towards the top thereof. The front side sheet, the rear side sheet, the right side sheet, and the left side sheet each are made of a substantially flat but flexible material. The sides include pockets, and/or other supports, for holding tools. The top opening exposes the top platform of the ladder. A handle extends across the top opening, the bottom of the handle rests on the top platform of the free-standing ladder so that the top platform will remain unobstructed in normal use of the free-standing ladder. In addition, the front side sheet is shortening and includes an elastic portion whereby the use of the ladder is further unobstructed.
Finally, U.S. Pat. No. 5,647,453 to Cassells for a MULTI-PURPOSE LADDER APRON shows a multi-purpose ladder utility apron having four side panels, each adapted with a plurality of tool and accessory receptacles. The apron further includes a fold up storage tray on the ladder's top providing additional temporary storage space. Closure flaps and straps secure the apron to the ladder whether in its open or closed position such that the subject invention may be secured to the ladder during use, transport and storage and may be quickly removed for laundering. An optional lid is also pivotally attached to the apron and folds out to provide a work shelf. The apron's design accommodates use of the ladder's own fold-down shelf and permits use of all steps without sacrificing storage space for tools and the like. The apron may still further be adapted with a power receptacle so that power tools can easily be interchanged without disengaging the extension cord.
The prior art in general variously shows ladder-mounted tool holders with various accommodations to holding and supporting various special things, mostly tools and materials. The mode and manner by which an economically-constructed flexible fabric-based tool holder might reliably function both on and off a ladder, and particularly a step ladder, could, however, use improvement.
SUMMARY OF THE INVENTION
The present invention contemplates a flexible and collapsible multi-pocket truncated-pyramidally-shaped tool and material holder for removable use atop a step ladder. The holder removably fits to the top of a step ladder, there presenting (i) a large distended pouch suitable to receive and hold a paint can, (ii) a flat tray which doubles as the top step of the step ladder, and (iii) numerous other hooks, hangers, clips and the like from which various tools and materials may conveniently be hung. The step ladder tool and material holder is preferably made from canvas or cotton duck, nominally of 24 oz. weight, or from polyurethane coated cloth, by processes of sewing and/or gluing. So constructed with the five major surfaces of its main body in the shape of a truncated four-sided pyramid, the tool and material holder has adequate stability so that it (i) may be set upon a floor without collapsing, and (ii) may be picked up with but one hand to be set atop a step ladder.
The preferred tool and material holder, called a “ladder caddy”, has numerous attributes. It is characterized for having an extremely large number of pockets, cavities, loops, clips, hangers, hooks and the like which securely hold a great variety of power and hand tools, caulking guns, paint brushes and paint pads. Importantly, the holder has in particular a major loop—maintained open by an insert with a shape memory—for holding a paint bucket, most preferably of the two gallon size. A paint bucket—even when full—may be entered into, or withdrawn from, this supporting loop by use of but one hand. The bucket is held securely within the loop with its lip exposed—exactly as desired for painting.
There are preferably 39 or more pockets in the holder, a number more than 50% greater than the 24 pockets normally found in the most extensive riggers bag. This is in addition to, most preferably, 1 drill holster, 2 hammer/caulking gun holder loops, 1 electrical or masking tape roll holder, 1 key clip, 4 general purpose hooks and 4 general purpose tie tabs.
The stiffening member with shape memory for the loop, or pouch, that holds the paint bucket is normally a piece of plastic.
The plastic stiffening member causes the loop, or pouch, to distend when the receptacle is mounted to the top of a step ladder, making that a paint can may easily and reliably be entered into, and withdrawn from, the pouch by the use of but one hand.
This major loop is further, optionally, fitted with a downhanging skirt, and in this case the stiffening member also preferably has and presents a transverse extension which, when the receptacle is mounted to the top of step ladder, extends downwards into the skirt, holding neatly open a pouch thereby formed, with pockets to the pouch exterior being smartly presented. The downhanging skirt may also optionally have vertical strip of hook and loop material sewn on its interior wall roughly midway in its looping extension. This optional strip is matched to a like optional strip of complimentary hook and loop material that is located an a major surface positioned against the step ladder, The two complimentary strips are roughly opposite—180° across—the pouch of roughly circular cross-section. When the pouch is empty the two complimentary strips may be forced together, making the one, relatively larger, paint can pouch into a dual pouch for holding two relatively smaller paint cans, normally of one quart size. This “closure” or “constriction” of the pouch may be realized despite the presence of the stiffening member. The step ladder top receptacle of the present invention thus has a pouch that is optionally adaptably sized to two differently sized paint cans. As before, smaller paint cans can be entered into, and withdrawn from, the modified pouch with but one hand.
An area of the tool and material holder which is immediately over the top step of the step ladder, and which is relatively flat in use, is provided with a slightly raised rim, making a shallow tray feature where small objects such as screws and nails may be temporarily held without rolling off. Nonetheless to the presence of this shallow tray feature, the top surface of the holder may be stood upon, making that the top step of the step ladder is still available for use.
The top surface also presents mounting/un-mounting and carrying handles, preferably two such spaced-parallel on either elongate side of the shallow tray feature. When the two handles are grasped by the thumb and fingers of a one hand, it is possible to lift the entire receptacle, and all the contents thereof including any small items that may be within the tray, on and off the top of a step ladder, and to carry the receptacle and all its contents.
1. A Holder Device with a Loop for a Paint Pail
Accordingly, in one of its aspects the present invention is embodied in a holder device for holding various things including a paint pail at an apex of a step ladder.
The device has a) a rectangular top panel having four edges; b) a trapezoidally-shaped first side panel (i) connected at its first edge to a first edge of the top panel, and (ii) having a plurality of receptacles; c) a trapezoidally-shaped second side panel (i) connected at its first edge to a second edge, opposite to the top panel's first edge, of the top panel, and (ii) having a plurality of receptacles; d) a step-side panel (i) connected at its first edge to a third edge of the top panel, and also to a second edge of both the first and the second side panels, and (ii) having a plurality of receptacles; e) a front panel, connected at its first edge to a fourth edge of the top panel and also to a third edge, opposite to the second edges, of both first and the second side panels. To this structure in the substantial shape of a truncated four-side pyramid is added f) a loop member extending substantially level with the top panel from (i) where the top panel joins with the first side panel and the front panel (ii) in an arc to (iii) where the top panel joins with the second side panel and the front panel, so as to form a loop into which a paint can is suitably entered and held.
The loop member preferably contains a shape memory stiffening element, preferably plastic, for maintaining the arc of the loop into which the paint can is suitably entered and held even when the paint can is not present.
The loop member further, optionally, includes a downhanging skirt protecting and securing a cylindrical surface of a paint can entered into, and held by, the loop member. This downhanging skirt may optionally incorporate a substantially vertical strip of a first type of hook-and-loop fabric, in which case the front panel also includes a substantially vertical strip of a second type of hook-and-loop fabric complimentary to the first type. By this construction the strips of the downhanging skirt and of the front panel may be manually pressed together, causing the strips to hold together along their lengths so as to divide the major arc of the loop member into two smaller arcs each of which is suitable to receive and to hold a paint can of appropriate size.
The top panel preferably includes a peripheral rim (i) sufficiently high so as to form a shallow reservoir in which can be placed nails and screws and other small things without jeopardy that they will role off the holder device and the step ladder, but (ii) insufficiently high so as to preclude that a person should not stand upon the top panel and its rim and its reservoir, obtaining good and secure footing like as the person would obtain standing directly upon the top step of the step ladder.
The preferred connection of all panels is by sewing.
2. A Holder Device with a Top Tray
In another of its aspects the present invention is embodied in a holder device for holding various things at an apex of a step ladder, including on the level surface of the top step of the step ladder.
The holder device so functioning includes a) a rectangular top panel having (i) four edges and (ii) a peripheral rim sufficiently high so as to form a shallow reservoir in which can be placed nails and screws and other small things without jeopardy that they will role off the holder device and the step ladder, but insufficiently high so as to preclude that a person should not stand upon the top panel and its rim and its reservoir when the holder device is mounted at the top step of the step ladder.
The holder device further includes b) a trapezoidally-shaped first side panel (i) connected at its first edge to a first edge of the top panel, and (ii) having a plurality of receptacles; c) a trapezoidally-shaped second side panel (i) connected at its first edge to a second edge, opposite to the top panel's first edge, of the top panel, and (ii) having a plurality of receptacles; d) a step-side panel (i) connected at its first edge to a third edge of the top panel, and also to a second edge of both the first and the second side panels, and (ii) having a plurality of receptacles; and e) a front panel, connected at its first edge to a fourth edge of the top panel and also to a third edge, opposite to the second edges, of both first and the second side panels.
By this construction the connected panels constitute the holder device that is suitably mounted at the top step of a step ladder. The top panel overlies the top step, with the step-side panel overlying an uppermost portion of a step side of the step ladder, with the front panel overlying an uppermost portion of a front side of the step ladder, and with each of the two side panels overlying regions between the step side and the front side of the step ladder.
This holder device with a shallow reservoir further preferably includes f) a loop member extending substantially level with the top panel from (i) where the top panel joins with the first side panel and the front panel (ii) in an arc to (iii) where the top panel joins with the second side panel and the front panel, so as to form a loop into which a paint can is suitably entered and held.
These and other aspects and attributes of the present invention will become increasingly clear upon reference to the following drawings and accompanying specification.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring particularly to the drawings for the purpose of illustration only and not to limit the scope of the invention in any way, these illustrations follow:
FIG. 1 is a first diagrammatic perspective view of the preferred embodiment of a flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention in operative position atop a step ladder.
FIG. 2 is a second diagrammatic perspective view, rotated 180° in azimuth, of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIG. 1 .
FIG. 3 is a right side plan view of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2.
FIG. 4 is a left side plan view of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2.
FIG. 5 is a front side plan view of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2.
FIG. 6 is a top side plan view of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2.
FIG. 7 is a back side plan view of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2.
FIG. 8, consisting of FIGS. 8 a and 8 b, are respective detail top, and side, plan views of the top panel (only) of the preferred embodiment of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention previously seen in FIGS. 1 and 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is of the best mode presently contemplated for the carrying out of the invention. This description is made for the purpose of illustrating the general principles of the invention, and is not to be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
1. Objects of the Invention
In accordance with the shortcomings contained in the prior art, it is an object of the present invention to provide a convenient device through the use of which laddermen may minimize the number of up-and-down trips required them on a given task.
It is an object of this invention to provide a means for caddying tools used by laddermen.
It is a further object of this invention to provide a means for caddying tools used by laddermen which is ergonomically enjoyable.
It is a further object of this invention to provide a means for caddying tools used by laddermen which is cost-effective enough in its manufacture to gain wide acceptance by industry.
Finally, it is yet another object of this invention to provide a means for caddying tools used by laddermen which is useful by tradesmen in all fields.
As an added advantage, the instant invention eliminates the need for the workman to carry heavy tools on his belt which might otherwise tend to contribute to a situation of imbalance, which could catalyze a mishap.
The objects of this invention are achieved by providing a novel fabric hood which is affixable to the top portion of the step-ladder. The uppermost two rungs (including the top rung) and the frame members of the ladder join together so as to form the framework of an essentially trapezoidally-shaped, or, more precisely, a truncated-pyramidally-shaped volume at the top of the step-ladder. The hood of the present invention is shaped so that it encloses this volume in the shape of a truncated four-side pyramid. The hood of the present invention also comprised pocket portions on its surfaces in which various tools and other implements such as screws, solder, nails, hammers, saws, wrenches, etc. may be securely housed.
An unexpected advantage of the present invention is that the hood contributes to the structural strength of the ladder and provides increased traction for the topmost step.
A further unexpected advantage of the present invention is that the center of gravity of the ladder to which the instant device is attached is reduced by virtue of the locations of the tools and implements held being lower than they would be if within a tool box resting on the top step of the ladder. This increased stability contributes to safety.
2. Preferred Embodiment of the Invention
A diagrammatic perspective view of the preferred embodiment of a flexible truncated-pyramidally-shaped tool and material holder 1 in accordance with the present invention in operative position atop a step ladder 2 (shown in phantom line, for not being part of the present invention) is shown at a first angular perspective in FIG. 1, and at a second, 180°-separated, angular perspective in FIG. 2 .
The holder 2 is preferably made from fabric, cloth, canvas or cotton duck, nominally of 24 oz. weight, or from polyurethane coated cloth, by processes of gluing and/or, preferably, sewing. The holder thus has angles that are gradual, and that may be less sharp than is depicted in the drawings, which are rendered to show the holder 2 with all corners sharp, and extensions full, for purposes of explaining the present invention. Due to its construction from flexible material, the holder 1 assumes the substantial geometric configuration of the structure to which it is mounted, or the apex of the step ladder 2 . This makes that the holder 1 is in the substantial shape of a truncated four-side pyramid (although the pyramid is not regular, with all its angles equal).
The truncated-pyramidally-shaped tool and material holder 1 has (i) five major panels and (ii) one major loop, or pouch, that define its shape. A back panel 11 (best seen in FIG. 1) is connected along a first side edge to a corresponding first side edge of a first side panel 12 (best seen in FIG. 2) which is itself connected along its second side edge to a corresponding first side edge of a front panel 13 (best seen in FIG. 2) which is itself connected along its second side edge to a corresponding first side edge of the second side panel 14 (best seen in FIG. 1) which finally joins at its second side edge back with the second side edge of the first side panel 11 . The top edges of each of the first side panel 11 , the front panel 12 , the second side panel 13 , and the back panel 14 are connected to a corresponding four edges of the top panel 14 (seen in both FIGS. 1 and 2 ). The front panel 11 fits over and against uppermost regions of the rung, or step, or front portion of the stepladder 2 . The back panel 14 correspondingly fits over and against uppermost regions of the back portion of the stepladder 2 . Both side panels 12 , 14 bridge the trapezoidally-shaped area between the legs of the step ladder 2 , in other words between its front and rear portions at the apex. The top panel 15 fits on, over and against the top step of the step ladder.
The top panel 15 has and presents (i) a raised peripheral rim 151 and (ii) handles 152 , both of which will be further discussed in conjunction with FIG. 8 .
The major loop, or pouch, of the truncated-pyramidally-shaped tool and material holder 1 is defined by the loop, or band, 16 . This loop 16 extends, as illustrated in both FIGS. 1 and 2, in an arc between, on a one side, (i) the connection of side panel 12 and front panel 13 and, on its other side, (ii) the connection of side panel 14 and front panel 13 . The loop 16 is itself stiff (more so than the fabric of which the holder 1 is mostly made), or is stiffened by incorporation of an internal member 161 (shown in dashed line) so as to reliably extend in an arc, or bow (as illustrated). There may be used as member 161 , for example, a length of unbreakable plastic strip which is normally positioned sewn into the loop 16 at its upper extremity, as illustrated, to impart stiffness.
A preferred configuration of the second side panel 14 is shown in detail plan view in FIG. 3; the configuration of the first side panel 12 in FIG. 4; the configuration of the combined back panel 13 and loop panel 16 in FIG. 5; the configuration of the front panel 11 in FIG. 7; and the configuration of the top panel 15 in FIGS. 8 a and 8 b.
The side panel 14 has and presents, by way of example, a drill holster 141 , normally of 5½″ by 6¾″ size; a first-level pocket 142 of nominal size 3″×4″; two second-level pockets 143 and 144 on the drill holster 141 each of nominal size 4″×3″; and a number of third-level pockets 145 each of nominal 3″×1½″ size on the second-level pocket 144 . There is additionally preferably provided a hammer or caulking gun loop 146 , a hook 147 , a tape hanger 148 , a clip 149 , and two tie tabs 140 .
Similarly, side panel 12 shown in FIG. 4 preferably has and presents a first/level pocket 121 or nominal size 6″×10″, the upper lip of which pocket 121 is joined with hook-and-loop fabric 1211 . A second-level pocket 122 is of nominal size 7″×10″. A third-level pocket 123 is of nominal size 7″×6″. Two fourth-level pockets 124 are of nominal size 3½″×5″ each; two fifth-level pockets 125 are of nominal size 3½″×4″ each; and two sixth-level pockets 126 are of nominal size 3½″×2″. A tie tab 127 is affixed to one of the sixth-level pockets 126 , and a hammer loop 128 to the other. As with the side panel 14 , two tie tabs 129 are presented.
The combination of the back panel 13 and loop panel 16 shown in FIG. 5 presents, as well as the major pouch 162 defined by the loop 16 itself, multiple pockets. Defined by the back panel 13 are a hierarchy of pockets: two first-level pockets 131 , optionally sealed at the lip with hook-and-loop fastener, of nominal size 14″×8″, two second-level pockets 132 of nominal size 6½″ by 6″ each, two third-level pockets 133 of nominal size 6½″ by 4″ each, and two fourth-level pockets 134 of nominal size 6½″ by 3″ each. The loop, or band, 16 has to its exterior preferably four first-level pockets 163 of nominal size 6″ by 5″ each.
There is optionally included a vertical strip 135 of a first-type of hook and loop material on the exterior wall of the back panel 3 , and a like strip 164 of complimentary, second-type, hook and loop material on the interior wall of the loop, or band, 16 ,
As illustrated in FIG. 6, the two strips 135 , 164 may be pressed together, drawing the major loop 16 inward so as to create two smaller arcuate loops. The plastic stiffening member 161 (see FIGS. 1 and 2 ), should it be present, is neither damaged nor permanently deformed by this operation, which may be reversed. The sub-pouches, or reservoirs, 162 a , 162 b thus created will hold small paint pails, or cans.
Continuing in FIG. 7, the front panel 11 has a plethora of pockets. Pocket 111 is of nominal size 14″×10″; two pockets 112 of nominal size 7″×8″; two pockets 113 of nominal size 4″×6″; two pockets 114 of nominal size 4″×4″; two pockets 115 of nominal size 4″×3″; one pocket 116 of nominal size 6″×6″; one pocket 117 of nominal size 6″×4″; and one pocket 118 of nominal size 6″×3″.
Finally, the top panel 15 is shown in top plan view in FIG. 8 a, and in side plan view in FIG. 8 b. The panel 15 has a raised peripheral rim 151 which is normally made from a puckered seam of sewn fabric. It is thus very tough and resilient, and may suitably support standing. Nonetheless that the raised peripheral rim 151 creates only a shallow reservoir 153 , it is sufficient to retain small nails, screws, bolts, nuts and the like within the reservoir 153 , and conveniently at the top step of the step ladder 2 (shown in FIGS. 1 and 2 ). The elongate handles 152 are commonly made from multiple layers of the same fabric or canvas from which the holer 1 is constructed. They are sufficiently strong so as to permit the entire holder 1 and its contents to be picked up by one hand. When the holder 1 is so picked up by its handles 1 , it will tend to closed and buckle along the elongate length of reservoir 151 , holding securely any contents thereof, while the panels 11 - 14 spread at the base, facilitating both that (i) the holder 1 may subsequently be set upright upon a floor or other surface, or (ii) that (ii) the holder 1 may be conveniently readily re-positioned atop a step ladder.
Although specific embodiments of the invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and are merely illustrative of but a small number of the many possible specific embodiments to which the principles of the invention may be applied. Various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention as further defined in the appended claims.
For example, the pockets may be contoured to receive and retain specific wrenches, pliers, screwdrivers and other hand tools. For example, there may optionally be added a means for adjusting the tightness of at least one of the panels about the structural members of a step ladder, for example an elastic strap, or a pull cord.
For example, any of the pockets may optionally be sealed by any of (i) a hook-and-loop type fastener, (ii) a zipper and/or (iii) a conventional fastener selected from the group consisting of a button and a hole, a snap fastener, and a rivet.
In accordance with the preceding explanation, variations and adaptations of the flexible truncated-pyramidally-shaped tool and material holder in accordance with the present invention will suggest themselves to a practitioner of the mechanical design arts.
In accordance with these and other possible variations and adaptations of the present invention, the scope of the invention should be determined in accordance with the following claims, only, and not solely in accordance with that embodiment within which the invention has been taught. | A tool and material holder fitting to the top of a step ladder has an extremely large number of pockets, cavities, loops, clips, hangers, hooks and the like which securely hold a great variety of power and hand tools, caulking guns, paint brushes and paint pads. A major loop maintained open by an insert with a shape memory holds a large paint pail, bucket or can, and is optionally re-sizable to hold one or two smaller cans. A shallow reservoir on a top panel overlying the top step of the step ladder holds small items but still permits standing on the top step. | 1 |
FIELD
The present disclosure relates generally to the field of call status and control. More particularly, the present disclosure relates to headset call status and control.
BACKGROUND
This background section is provided for the purpose of generally describing the context of the disclosure. Work of the presently named inventor(s), to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
To meet the demands of conducting business professionally in a mobile environment, mobile professionals seek out premium headsets with sophisticated functions such as microphone mute, volume, answer/end call, and even voice commands to help manage the quality of their communications. User interfaces to control these functions typically require physical buttons or a list of voice commands that the wearer can speak, usually stored in the firmware of the headset.
The lack of a visual user interface for these functions while wearing the headset causes anxiety to the user. Users become uncertain of the microphone mute status of the call, or miss critical information when on a call in loud environments, because they can't find the buttons to change call volume in the headset.
Previous solutions fall into two categories of call control interfaces. With a physical headset user interface, buttons on the headset itself control the microphone mute status of a call, volume of the call, redial, call answer/end ability, and the like. With a PC/Mobile graphical user interface, voice controls stored in the headset firmware allow hands-free voice control including but not limited to pairing the device, answering/ending a call, recognizing and calling a stored contact by name, querying what other voice commands are available with “what can I say?” and the like. Selectable icons to control the call status (microphone mute, volume, answer/end) are typically found in the user interface of softphone clients or in the telephony client of a mobile device/PC.
SUMMARY
In general, in one aspect, an embodiment features a wearable device comprising: an output device; a receiver configured to communicate over a wireless link with a phone; and a processor configured to cause the output device to indicate a status of a headset, the headset being in wireless communication with the phone, responsive to the receiver receiving, over the wireless link, an indication of the status of the headset.
Embodiments of the wearable device may include one or more of the following features. In some embodiments, the status of the headset includes at least one of: a microphone mute status; a volume level; a power level of the headset; a notification of maximum volume; a notification of minimum volume; a notification of call start; and a notification of call end. Some embodiments comprise a transmitter; and a processor configured to cause the transmitter to transmit a control signal over the wireless link responsive to user operation of the wearable device. In some embodiments, the control signal includes at least one of: a microphone mute on control signal; a microphone mute off control signal; a volume up control signal; a volume down control signal; a call start control signal; a call answer control signal; a call redial control signal; and a call end control signal. In some embodiments, the wearable device includes at least one of: a wristwatch; a wristband; a ring; a necklace; and a garment. In some embodiments, the phone includes at least one of: a smartphone; a feature phone; a soft phone; and a desk phone.
In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer in a wearable device to perform functions comprising: receiving, from a phone, over a wireless link with the phone, an indication of a status of a headset; and causing an output device of the wearable device to indicate the status of the headset responsive to receiving the indication of the status of the headset.
Embodiments of the computer-readable media may include one or more of the following features. In some embodiments, the status of the headset includes at least one of: a microphone mute status; a volume level; a power level of the headset; a notification of maximum volume; a notification of minimum volume; a notification of call start; and a notification of call end. In some embodiments, the functions further comprise: causing a transmitter of the wearable device to transmit a control signal over the wireless link responsive to user operation of the wearable device. In some embodiments, the control signal includes at least one of: a microphone mute on control signal; a microphone mute off control signal; a volume up control signal; a volume down control signal; a call start control signal; a call answer control signal; a call redial control signal; a call end control signal. In some embodiments, the wearable device includes at least one of: a wristwatch; a wristband; a ring; a necklace; and a garment. In some embodiments, the phone includes at least one of: a smartphone; a feature phone; a soft phone; and a desk phone.
In general, in one aspect, an embodiment features a wearable device comprising: an output device; a receiver configured to communicate over a wireless link with a headset; and a processor configured to cause the output device to indicate a status of a headset responsive to the receiver receiving, over the wireless link, an indication of the status of the headset.
Embodiments of the wearable device may include one or more of the following features. In some embodiments, the status of the headset includes at least one of: a microphone mute status; a volume level; a power level of the headset; a notification of maximum volume; a notification of minimum volume; a notification of call start; and a notification of call end. Some embodiments comprise a transmitter; and a processor configured to cause the transmitter to transmit a control signal over the wireless link responsive to user operation of the wearable device. In some embodiments, the control signal includes at least one of: a microphone mute on control signal; a microphone mute off control signal; a volume up control signal; a volume down control signal; a call start control signal; a call answer control signal; a call redial control signal; and a call end control signal. In some embodiments, the wearable device includes at least one of: a wristwatch; a wristband; a ring; a necklace; and a garment.
In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer in a wearable device to perform functions comprising: receiving, from a headset, over a wireless link with the headset, an indication of a status of the headset; and causing an output device of the wearable device to indicate the status of the headset responsive to receiving the indication of the status of the headset.
Embodiments of the computer-readable media may include one or more of the following features. In some embodiments, the status of the headset includes at least one of: a microphone mute status; a volume level; a power level of the headset; a notification of maximum volume; a notification of minimum volume; a notification of call start; and a notification of call end. In some embodiments, the functions further comprise: causing a transmitter of the wearable device to transmit a control signal over the wireless link responsive to user operation of the wearable device. In some embodiments, the control signal includes at least one of: a microphone mute on control signal; a microphone mute off control signal; a volume up control signal; a volume down control signal; a call start control signal; a call answer control signal; a call redial control signal; a call end control signal. In some embodiments, the wearable device includes at least one of: a wristwatch; a wristband; a ring; a necklace; and a garment.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 shows elements of a headset system according to an embodiment that includes a smartphone.
FIG. 2 shows elements of a headset system according to an embodiment that does not include a smartphone.
FIG. 3 shows elements of a headset according to one embodiment.
FIG. 4 shows elements of a smartwatch according to one embodiment.
FIG. 5 shows elements of a smartphone according to one embodiment.
FIG. 6 shows a status reporting process for the headset system of FIG. 1 according to one embodiment.
FIGS. 7A and 7B shows a headset control process for the headset system of FIG. 1 according to one embodiment.
FIG. 8 shows a status reporting process for the headset system of FIG. 2 according to one embodiment.
FIG. 9 shows a headset control process for the headset system of FIG. 2 according to one embodiment.
FIG. 10 shows a smartphone display showing an icon that indicates the headset volume is at minimum volume (no sound).
FIG. 11 shows a smartphone display showing an icon that indicates the headset microphone is muted.
FIG. 12 shows a watch display showing an icon that indicates the headset volume is at minimum volume (no sound).
FIG. 13 shows a watch display showing an icon that indicates the headset microphone is muted.
The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears.
DETAILED DESCRIPTION
Embodiments of the present disclosure provide wearable devices for headset status and control. In the described embodiments the wearable devices are smartwatches, that is, wristwatches that include processors, output devices such as displays, speakers, and haptic devices, user-operable controls, and wireless transceivers. However the techniques described herein are applicable to other wearable devices as well. For example the wearable devices can include wristbands, rings, necklaces, garments, and the like.
Such a wrist-worn call control center for headset functions provides users with the trust they need during important mobile conversations. The smartwatch and headset may be synchronized at all times. In other words, if the user mutes the headset microphone from the headset the smart watch gives a visual representation that the user is on microphone mute. Then if the user unmutes the headset microphone from the smart watch, the headset microphone comes off mute. The smartwatch then acts not just as a command/control vehicle for the headset functions but also an in-line-of-sight visual representation of the call state.
End users now have a visual user interface for functions that previously were difficult to find and use but still did not give users reassurance that the selected function was being effectively carried out. This solution eliminates the anxiety users feel on important calls by providing visual reassurance of the call state.
Other features are contemplated as well.
FIG. 1 shows elements of a headset system 100 according to an embodiment that includes a smartphone. Although in the described embodiment elements of the headset system 100 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the headset system 100 may be implemented in hardware, software, or combinations thereof.
Referring to FIG. 1 , the headset system 100 includes a headset 102 , a smartwatch 104 , a smartphone 106 , and a network 108 . In other embodiments, the smartphone 106 may be replaced by a feature phone, a desk phone, a soft phone, a computer, and the like. The network 108 may be a mobile network, a computer network or the like. The headset 102 and the smartphone 106 may communicate over a wireless link 110 . The smartwatch 104 and the smartphone 106 may communicate over a wireless link 112 . The smartphone 106 and the network 108 may communicate over a wireless link 114 . As used herein, wireless refers to a communications, monitoring, or control system in which electromagnetic or acoustic waves carry a signal through atmospheric space rather than along a wire.
The wireless links 110 , 112 , 114 may be Bluetooth links, Digital Enhanced Cordless Telecommunications (DECT) links, cellular links, Wi-Fi links, or the like. The headset 102 may exchange audio, status messages, command messages, and the like with the smartphone 106 over the wireless link 110 . The smartwatch 104 may exchange status messages, command messages, and the like with the smartphone 106 over the wireless link 110 . The smartphone 106 may exchange audio, status messages, and command messages with the network 108 over the wireless link 114 .
FIG. 2 shows elements of a headset system 200 according to an embodiment that does not include a smartphone. Although in the described embodiment elements of the headset system 200 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the headset system 200 may be implemented in hardware, software, or combinations thereof.
Referring to FIG. 2 , the headset system 200 includes a headset 202 , a smartwatch 204 , and a network 208 . The network 208 may be a mobile network, a computer network or the like. The headset 102 and the smartwatch 204 may communicate over a wireless link 210 . The smartwatch 204 and the network 208 may communicate over a wireless link 212 . In this embodiment, the smartwatch 204 is capable of phone calls, and so no smartphone is needed.
The wireless links 210 , 212 may be Bluetooth links, Digital Enhanced Cordless Telecommunications (DECT) links, cellular links, Wi-Fi links, or the like. The headset 102 may exchange audio, status messages, command messages, and the like with the smartwatch 204 over the wireless link 210 . The smartwatch 204 may exchange audio, status messages, command messages, and the like with the network 208 over the wireless link 212 .
FIG. 3 shows elements of a headset 300 according to one embodiment. The headset 300 may be used as the headset 102 of FIG. 1 or as the headset 202 of FIG. 2 . Although in the described embodiment elements of the headset 300 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the headset 300 may be implemented in hardware, software, or combinations thereof.
Referring to FIG. 3 , the headset 300 may include one or more of a transceiver 312 , a processor 308 , a memory 310 , a microphone 314 , a speaker 316 , one or more user-operable controls 320 , and a power supply 326 . The headset 300 may include other elements as well. The elements of headset 300 may receive power from the power supply 326 over one or more power rails 330 . Various elements of the headset 300 may be implemented as one or more integrated circuits.
The processor 308 may execute applications stored in the memory 310 . The processor 308 may include digital signal processors, analog-to-digital converters, digital-to-analog converters, and the like. The processor 308 may communicate with other elements of the headset 300 over one or more communication busses 328 . The transceiver 312 may employ any communication protocol, including wired and wireless communication protocols. The wireless protocols may include Bluetooth, Bluetooth Low-Energy (BLE), Wi-Fi, Digital Enhanced Cordless Telecommunications (DECT), cellular, near-field communications (NFC), and the like. The transceiver 312 may employ multiple communication protocols. The user-operable controls 320 may include buttons, slide switches, capacitive sensors, touch screens, and the like.
FIG. 4 shows elements of a smartwatch 400 according to one embodiment. The smartwatch 400 may be used as the smartwatch 104 of FIG. 1 or as the smartwatch 204 of FIG. 2 . Although in the described embodiment elements of the smartwatch 400 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the smartwatch 400 may be implemented in hardware, software, or combinations thereof.
Referring to FIG. 4 , the smartwatch 400 may include one or more of a transceiver 412 , a processor 408 , a memory 410 , a microphone 414 , a speaker 416 , one or more output devices 418 , one or more user-operable controls 420 , and a power supply 426 . The elements of smartwatch 400 may receive power from the power supply 426 over one or more power rails 430 . Various elements of the smartwatch 400 may be implemented as one or more integrated circuits. The smartwatch 400 may include other elements as well.
The processor 408 may execute applications stored in the memory 410 . The processor 408 may communicate with other elements of the smartwatch 400 over one or more communication busses 428 . The elements of smartwatch 400 may receive power from the power supply 426 over one or more power rails 430 . Various elements of the smartwatch 400 may be implemented as one or more integrated circuits.
The transceiver 412 may employ any communication protocol, including wired and wireless communication protocols. The wireless protocols may include Bluetooth, Bluetooth Low-Energy (BLE), Wi-Fi, Digital Enhanced Cordless Telecommunications (DECT), cellular, near-field communications (NFC), and the like. The transceiver 412 may employ multiple communication protocols. The processor 408 may include digital signal processors, analog-to-digital converters, digital-to-analog converters, and the like. The output devices 418 may include displays, speakers, haptic devices, and the like. The displays may be implemented as a touch screen or the like. The user-operable controls 420 may include buttons, slide switches, capacitive sensors, touch screens, and the like.
FIG. 5 shows elements of a smartphone 500 according to one embodiment. The smartphone 500 may be used as the smartphone 106 of FIG. 1 . Although in the described embodiment elements of the smartphone 500 are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the smartphone 500 may be implemented in hardware, software, or combinations thereof.
Referring to FIG. 5 , the smartphone 500 may include one or more of a transceiver 512 , a processor 508 , a memory 510 , a microphone 514 , a speaker 516 , one or more output devices 518 , one or more user-operable controls 520 , and a power supply 526 . The elements of smartphone 500 may receive power from the power supply 526 over one or more power rails 530 . Various elements of the smartphone 500 may be implemented as one or more integrated circuits. The smartphone 500 may include other elements as well.
The processor 508 may execute applications stored in the memory 510 . The processor 508 may communicate with other elements of the smartphone 500 over one or more communication busses 528 . The elements of smartphone 500 may receive power from the power supply 526 over one or more power rails 530 . Various elements of the smartphone 500 may be implemented as one or more integrated circuits.
The transceiver 512 may employ any communication protocol, including wired and wireless communication protocols. The wireless protocols may include Bluetooth, Bluetooth Low-Energy (BLE), Wi-Fi, Digital Enhanced Cordless Telecommunications (DECT), cellular, near-field communications (NFC), and the like. The transceiver 512 may employ multiple communication protocols. The processor 508 may include digital signal processors, analog-to-digital converters, digital-to-analog converters, and the like.
The output devices 518 may include displays, speakers, haptic devices, and the like. The displays may be implemented as touch screens or the like. The user-operable controls 520 may include buttons, slide switches, capacitive sensors, touch screens, and the like.
FIG. 6 shows a status reporting process 600 for the headset system 100 of FIG. 1 according to one embodiment. Although in the described embodiments the elements of process 600 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process 600 can be executed in a different order, concurrently, and the like. Also some elements of process 600 may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process 600 can be performed automatically, that is, without human intervention.
Referring to FIG. 6 , at 602 , a status may be generated at the headset 102 . As used herein the term “status” may include a status change, notification of a status, and the like. At 604 , the status change or notification of status may be generated responsive to user operation of the headset 102 . For example, the user may operate the user-operable controls 320 of the headset 102 . Responsive to the operation of volume controls, the volume may change, and if a maximum or minimum volume is reached, the headset 102 may generate a notification of maximum or minimum volume, which may be announced for the user over the speaker 316 of the headset 102 . Responsive to the operation of a microphone mute control, audio generated by the microphone 314 may be blocked from transmission from the headset 102 by the transceiver 312 , and the headset 102 may generate a notification of microphone mute on or microphone mute off, which may be announced for the user over the speaker 316 of the headset 102 . Responsive to the operation of a call control, the headset 102 may start a call or end a call.
At 606 , the status may be generated responsive to an internal event at the headset 102 . for example, the processor 308 may determine that the power level of the power supply 326 has dropped below a threshold, and may therefore announce this status change for the user over the speaker 316 of the headset.
At 608 , the status may be generated responsive to an inquiry from the smartphone 106 . For example, the smartphone 106 may send a message over the wireless link 110 that requests the power level of the power supply 326 of the headset 102 .
At 610 , responsive to generation of the status, the headset 102 may send an indication of the status to the smartphone 106 . That is, the transceiver 312 of the headset 102 may transmit a message over the wireless link 110 , where the message represents the indication of the status. At 612 , the smartphone 106 may receive the indication of the status. That is, the transceiver 512 of the smartphone 106 may receive the message transmitted by the headset 102 over the wireless link 110 .
At 614 , responsive to receiving the indication of the status from the headset 102 , the smartphone 106 may indicate the status of the headset 102 . That is, the processor 508 of the smartphone 106 may cause an output device 518 of the smartphone 106 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset 102 , a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartphone 106 may show a message announcing “Call End” or the like. As another example, a haptic device of the smartphone 106 may vibrate to indicate the headset 102 has reached maximum volume. FIG. 10 shows a smartphone display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 11 shows a smartphone display showing an icon that indicates the headset microphone 314 is muted.
At 616 , responsive to receiving the indication of the status from the headset 102 , the smartphone 106 may send an indication of the status to the smartwatch 104 . That is, the transceiver 512 of the smartphone 106 may transmit a message over the wireless link 112 , where the message represents the indication of the status.
At 618 , the smartwatch 104 may receive the indication of the status. That is, the transceiver 412 of the smartwatch 104 may receive the message transmitted by the smartphone 106 over the wireless link 112 .
At 620 , responsive to receiving the indication of the status from the smartphone 106 , the smartwatch 104 may indicate the status of the headset 102 . That is, the processor 408 of the smartwatch 104 may cause an output device 418 of the smartwatch 104 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset, a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartwatch 104 may show a message announcing “Call End” or the like. As another example, a haptic device may vibrate to indicate the headset 102 has reached maximum volume. FIG. 12 shows a watch display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 13 shows a watch display showing an icon that indicates the headset microphone 314 is muted.
FIGS. 7A and 7B shows a headset control process 700 for the headset system 100 of FIG. 1 according to one embodiment. Although in the described embodiments the elements of process 700 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process 700 can be executed in a different order, concurrently, and the like. Also some elements of process 700 may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process 700 can be performed automatically, that is, without human intervention.
Referring to FIG. 7 , at 702 , a headset control signal may be generated at the smartwatch 104 . The headset control signals may include a microphone mute on control signal, a microphone mute off control signal, a volume up control signal, a volume down control signal, a call start control signal, a call answer control signal, a call redial control signal, a call end control signal, and the like.
At 704 , the headset control signal may be generated responsive to user operation of the smartwatch 104 . For example, the user may operate controls 420 of the smartwatch 104 for volume up, volume down, call start, call answer, call redial, call end, and the like.
At 706 , the headset control signal may be generated responsive to an internal event at the smartwatch 104 . For example, the processor 408 may determine that a call has been ended by another party to the call.
At 708 , responsive to generation of the headset control signal, the smartwatch 104 may send an indication of the headset control signal to the smartphone 106 . That is, the transceiver 412 of the smartwatch 104 may transmit a message over the wireless link 112 , where the message represents the headset control signal.
At 710 , the smartphone 106 may receive the indication of the headset control signal. That is, the transceiver 512 of the smartphone 106 may receive the message transmitted by the smartwatch 104 over the wireless link 112 .
At 712 , responsive to receiving the indication of the headset control signal from the smartwatch 104 , the smartphone 106 may send an indication of the headset control signal to the headset 102 . That is, the transceiver 512 of the smartphone 106 may transmit a message over the wireless link 110 , where the message represents the indication of the headset control signal.
At 714 , the headset 102 may receive the indication of the headset control signal. That is, the transceiver 312 of the headset 102 may receive the message transmitted by the smartphone 106 over the wireless link 110 .
At 716 , responsive to receiving the indication of the headset control signal from the smartphone 106 , the headset 102 may act on the headset control signal. That is, the processor 308 of the headset 102 may perform the action indicated by the headset control signal. For example, the processor 308 may mute or un-mute the microphone 314 of the headset 102 , change the volume level of the headset 102 , start, answer, or end a call, redial a number, determine and report a power level of the headset 102 , or the like.
Acting on the headset control signal may result in a change of status at the headset 102 . At 718 , responsive to the status change, the headset 102 may send an indication of the new status to the smartphone 106 . That is, the transceiver 312 of the headset 102 may transmit a message over the wireless link 110 , where the message represents the indication of the new status.
At 720 , responsive to receiving the indication of the status from the headset 102 , the smartphone 106 may indicate the status of the headset 102 . That is, the processor 508 of the smartphone 106 may cause an output device 518 of the smartphone 106 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset 102 , a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartphone 106 may show a message announcing “Call End” or the like. As another example, a haptic device of the smartphone 106 may vibrate to indicate the headset 102 has reached maximum volume. FIG. 10 shows a smartphone display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 11 shows a smartphone display showing an icon that indicates the headset microphone 314 is muted. At 722 , responsive to receiving the indication of the status from the headset 102 , the smartphone 106 may send an indication of the status to the smartwatch 104 . That is, the transceiver 512 of the smartphone 106 may transmit a message over the wireless link 112 , where the message represents the indication of the status.
At 724 , the smartwatch 104 may receive the indication of the status. That is, the transceiver 412 of the smartwatch 104 may receive the message transmitted by the smartphone 106 over the wireless link 112 .
At 726 , responsive to receiving the indication of the status from the smartphone 106 , the smartwatch 104 may indicate the status of the headset 102 . That is, the processor 408 of the smartwatch 104 may cause an output device 418 of the smartwatch 104 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset 102 , a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartwatch 104 may show a message announcing “Call End” or the like. As another example, a haptic device may vibrate to indicate the headset 102 has reached maximum volume. FIG. 12 shows a watch display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 13 shows a watch display showing an icon that indicates the headset microphone 314 is muted.
FIG. 8 shows a status reporting process 800 for the headset system 200 of FIG. 2 according to one embodiment. Although in the described embodiments the elements of process 800 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process 800 can be executed in a different order, concurrently, and the like. Also some elements of process 800 may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process 800 can be performed automatically, that is, without human intervention.
Referring to FIG. 8 , at 802 , a status may be generated at the headset 202 . As used herein the term “status” may include a status change, notification of a status, and the like. At 804 , the status change or notification of status may be generated responsive to user operation of the headset 202 . For example, the user may operate the user-operable controls 320 of the headset 202 . Responsive to the operation of volume controls, the volume may change, and if a maximum or minimum volume is reached, the headset 202 may generate a notification of maximum or minimum volume, which may be announced for the user over the speaker 316 of the headset 202 . Responsive to the operation of a microphone mute control, audio generated by the microphone 314 may be blocked from transmission from the headset 202 by the transceiver 312 , and the headset 202 may generate a notification of microphone mute on or microphone mute off, which may be announced for the user over the speaker 316 of the headset 202 . Responsive to the operation of a call control, the headset 202 may start a call or end a call.
At 806 , the status change or notification of status may be generated responsive to an internal event at the headset 202 . For example, the processor 308 may determine that the power level of the power supply 326 has dropped below a threshold, and may therefore announce this status change for the user over the speaker 316 of the headset.
At 808 , the status may be generated responsive to an inquiry from the smartwatch 204 . For example, the smartwatch 204 may send a message over the wireless link 210 that requests the power level of the power supply 326 of the headset 202 .
At 810 , responsive to generation of the status, the headset 202 may send an indication of the status to the smartwatch 204 . That is, the transceiver 312 of the headset 202 may transmit a message over the wireless link 210 , where the message represents the indication of the status.
At 812 , the smartwatch 204 may receive the indication of the status. That is, the transceiver 412 of the smartwatch 204 may receive the message transmitted by the headset 202 over the wireless link 210 .
At 814 , responsive to receiving the indication of the status from the headset 202 , the smartwatch 204 may indicate the status of the headset 202 . That is, the processor 408 of the smartwatch 204 may cause an output device 418 of the smartwatch 204 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset, a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartwatch 204 may show a message announcing “Call End” or the like. As another example, a haptic device may vibrate to indicate the headset 202 has reached maximum volume. FIG. 12 shows a watch display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 13 shows a watch display showing an icon that indicates the headset microphone 314 is muted.
FIG. 9 shows a headset control process 900 for the headset system 200 of FIG. 2 according to one embodiment. Although in the described embodiments the elements of process 900 are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of process 900 can be executed in a different order, concurrently, and the like. Also some elements of process 900 may not be performed, and may not be executed immediately after each other. In addition, some or all of the elements of process 900 can be performed automatically, that is, without human intervention.
Referring to FIG. 9 , at 902 , a headset control signal may be generated at the smartwatch 204 . The headset control signals may include a microphone mute on control signal, a microphone mute off control signal, a volume up control signal, a volume down control signal, a call start control signal, a call answer control signal, a call redial control signal, a call end control signal, and the like.
At 904 , the headset control signal may be generated responsive to user operation of the smartwatch 204 . For example, the user may operate controls 420 of the smartwatch 204 for volume up, volume down, call start, call answer, call redial, call end, and the like.
At 906 , the headset control signal may be generated responsive to an internal event at the smartwatch 204 . For example, the processor 408 may determine that a call has been ended by another party to the call.
At 912 , responsive to generation of the headset control signal, the smartwatch 204 may send an indication of the headset control signal to the headset 202 . That is, the transceiver 412 of the smartwatch 204 may transmit a message over the wireless link 210 , where the message represents the headset control signal.
At 914 , the headset 202 may receive the indication of the headset control signal. That is, the transceiver 312 of the headset 202 may receive the message transmitted by the smartwatch 204 over the wireless link 210 .
At 916 , responsive to receiving the indication of the headset control signal from the smartwatch 204 , the headset 202 may act on the headset control signal. That is, the processor 308 of the headset 202 may perform the action indicated by the headset control signal. For example, the processor 308 may mute or un-mute the microphone 314 of the headset 202 , change the volume level of the headset 202 , start, answer, or end a call, redial a number, determine and report a power level of the headset 202 , or the like.
Acting on the headset control signal may result in a change of status at the headset 102 . At 918 , responsive to the status change, the headset 102 may send an indication of the new status to the smartwatch 204 . That is, the transceiver 312 of the headset 202 may transmit a message over the wireless link 210 , where the message represents the indication of the new status.
At 920 , the smartwatch 204 may receive the indication of the status. That is, the transceiver 412 of the smartwatch 204 may receive the message transmitted by the headset 202 over the wireless link 210 .
At 922 , responsive to receiving the indication of the status from the headset 202 , the smartphone 106 may indicate the status of the headset 202 . That is, the processor 508 of the smartwatch 204 may cause an output device 418 of the smartwatch 204 to generate an output representing the status. For example, the status may include a microphone mute status, a volume level, a power level of the headset 202 , a notification of maximum volume, a notification of minimum volume, a notification of call start, a notification of call end, and the like. For example, a display of the smartwatch 204 may show a message announcing “Call End” or the like. As another example, a haptic device of the smartwatch 204 may vibrate to indicate the headset 202 has reached maximum volume. FIG. 12 shows a watch display showing an icon that indicates the headset volume is at minimum volume (no sound). FIG. 13 shows a watch display showing an icon that indicates the headset microphone 314 is muted.
Various embodiments of the present disclosure can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Embodiments of the present disclosure can be implemented in a computer program product tangibly embodied in a computer-readable storage device for execution by a programmable processor. The described processes can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments of the present disclosure can be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, processors receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer includes one or more mass storage devices for storing data files. Such devices include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks; optical disks, and solid-state disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). As used herein, the term “module” may refer to any of the above implementations.
A number of implementations have been described. Nevertheless, various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims. | One embodiment features a wearable device having computer-readable media and comprising: an output device; a receiver configured to communicate over a wireless link with a phone; and a processor configured to cause the output device to indicate a status of a headset, the headset being in wireless communication with the phone, responsive to the receiver receiving, over the wireless link, an indication of the status of the headset. Another embodiment features a wearable device having associated computer-readable media and comprising: an output device; a receiver configured to communicate over a wireless link with a headset; and a processor configured to cause the output device to indicate a status of a headset responsive to the receiver receiving, over the wireless link, an indication of the status of the headset. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to and is a continuation of U.S. patent application Ser. No. 13/711,501, filed Dec. 11, 2012, which is a continuation of U.S. patent application Ser. No. 13/285,831, filed Oct. 31, 2011, which issued as U.S. Pat. No. 8,347,177, on Jan. 1, 2013, which is a continuation of U.S. patent application Ser. No. 12/862,561, filed Aug. 24, 2010, which issued as U.S. Pat. No. 8,051,360, on Nov. 1, 2011, which is a continuation of U.S. patent application Ser. No. 11/129,850, filed May 16, 2005, which issued as U.S. Pat. No. 7,783,953, on Aug. 24, 2010, which is a continuation of U.S. patent application Ser. No. 10/035,771, filed Dec. 26, 2001, which issued as U.S. Pat. No. 6,915,473, on Jul. 5, 2005, which claims the benefit of U.S. Provisional Patent Application Nos. 60/290,740, filed May 14, 2001; 60/314,993, filed Aug. 24, 2001; and 60/345,358, filed Oct. 25, 2001, which are incorporated by reference as if fully set forth herein.
BACKGROUND
The present invention relates to the field of wireless communications. One of the applications of the present invention is directed to a downlink signaling approach employing a modified cyclic redundancy check for both data protection and unique/group UE identification.
Wireless communication systems have become an integral link in today's modern telecommunications infrastructure. As such, they have become increasingly relied upon not only to support voice communications, but also data communications. Voice communications are relatively low-rate, symmetrical in the upstream and downstream bandwidths and are predictable in the amount of bandwidth required.
However, data communications can place severe burdens upon a telecommunication system, particularly a wireless telecommunication system. First, data communications can often require extremely high data rates. Second, the amount of bandwidth for a data related application can vary greatly from several kilohertz of bandwidth to several megahertz. Third, the amount of bandwidth in the upstream and downstream directions can be drastically different. For example, with a typical Internet browsing application, very little data is sent in the upstream direction while vast amounts of data are downloaded in the downstream direction. These factors can place severe constraints upon a wireless telecommunication system.
The Wideband CDMA (WCDMA) standard, as the leading global third generation (3G) (IMT-2000) standard, supports data rates up to 2, Mb/s in indoor/small-cell-outdoor environments and up to 384, kb/switch wide-area coverage, as well as support for both high-rate packet data and high-rate circuit-switched data. However to satisfy the future demands for packet-data services, there is a need for a substantial increase in this data rate, especially in the downlink. High speed downlink packet access (HSDPA) would allow WCDMA to support downlink peak data rates in the range of approximately 8-10, Mb/s for best-effort packet-data services. This rate is far beyond the IMT-2000, requirement of 2, Mb/s. It also enhances the packet-data capability in terms of lower delay and improved capacity.
One solution for supporting data communications is the allocation of dedicated channels to each user equipment (UE). However, this results in an extremely inefficient use of the bandwidth since such channels often remain idle for long durations.
An alternative to dedicated channels for each UE is the use of the high speed shared data channels and the packeting of data. In this method, a plurality of high speed data channels are shared between a plurality of UEs. Those UEs having data for transmission or reception are dynamically assigned one of the shared data channels. This results in a much more efficient use of the spectrum.
One such process for assigning a high speed shared data channel when a base station has data waiting for transmission to a particular UE is shown in FIGS. 1A-1C . Referring to FIG. 1A , an associated downlink dedicated physical channel (DPCH) is transmitted to each UE. The UE monitors associated downlink DPCH as well as the shared control channels (SCCH-HS). When there is no data being transmitted to the UE from the base station, the UE enters a standby mode whereby it periodically “wakes up” to attempt to monitor its associated downlink DPCH as well as SCCH-HSs. This permits the UE to save processing and battery resources.
If data at the base station is ready for transmission to the UE, a High Speed Downlink Shared Channel (HS-DSCH) indicator (HI) is transmitted in the associated DPCH. The HI has n-bit length, which points to one of 2 n , SCCH-HSs shown in FIG. 1B . For example a 2, bit HI can point to 4, SCCH-HSs, i.e., 00, 01, 10, or 11.
For the example shown in FIG. 1A , the HI is (1, 0) which points to the third channel shown in FIG. 1B . When the UE accesses the control channel identified by the HI, that particular SCCH-HS will direct the UE to the proper HS-DSCH, which has been allocated to the UE for reception of the data. As shown in FIG. 1C , for example, the UE tunes to HS-DSCH (001) that was identified by SCCH-HS (1, 0). The UE then receives the data intended for it over the HS-DSCH (001). It should be noted that the graphical representation of FIG. 1A-1C has been presented to illustrate the process of assigning HS-DSCHs, and the configuration and use of channels may differ slightly from actual implementation in HSDPA standards.
The process as described with reference to FIGS. 1A-1C provides an efficient method for assigning common data channels for transmission of data. Since packet data is intended for one or more, specific UEs, the UE identity (ID) is a critical parameter for signaling from the base station to the UE.
There are several prior art methods for signaling the UE ID between the base station and the UE. Referring to FIG. 2A , the first method appends the UE ID onto the data for transmission. The combination is fed to a cyclic redundancy check (CRC) generator, which outputs a CRC. The resulting data packet, which is ultimately transmitted, includes an X-bit data field, an M-bit UE ID and an N-bit CRC as shown in FIG. 2B . Although this provides adequate signaling of both the CRC and the UE ID, it is wasteful of signaling bandwidth.
Another prior art technique shown in FIG. 3A appends the UE ID onto the data field for input into the CRC generator. The CRC generator outputs a CRC. As shown in FIG. 3B , the data burst for transmission includes an X-bit data field and an N-bit CRC field. Although this also adequately signals the UE ID and the CRC between the base station and the UE, it is undesirable since it can only be used for unique UE Identification. This method also causes increased complexity of the UE when a group of UEs need to be identified.
SUMMARY
A method and apparatus is disclosed wherein a user equipment (UE) receives control information on a first channel and uses the control information to process a second channel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1C represent a prior art method for assigning shared data channels, where FIG. 1A illustrates the associated downlink channel, FIG. 1B illustrates a plurality of control channels and FIG. 1C illustrates a plurality of data channels.
FIG. 1D is a block diagram of the universal mobile telecommunication system network architecture.
FIG. 2A is a prior art user equipment identification (UE ID) specific cyclic redundancy check (CRC) method.
FIG. 2B illustrates the transmitted data burst including a data field, a UE ID field and a CRC field.
FIG. 3A is a second prior art user equipment identification (UE ID) specific cyclic redundancy check (CRC) method.
FIG. 3B illustrates the transmitted data burst including a data field and a CRC field.
FIG. 4A is a first embodiment of the present invention utilizing modulo 2 addition of the UE ID with the CRC to create a mask.
FIG. 4B is a data burst transmitted by the system of FIG. 4A including a data field and a mask field.
FIG. 5A is a second embodiment of the present invention including a CRC generator which is initialized using the UE ID.
FIG. 5B is a data burst transmitted by the embodiment of FIG. 5A including a data field and a CRC field.
FIG. 6A is a third embodiment of the present invention which modulo 2 adds the data field to a UE ID field padded with trailing zeros to create a mask.
FIG. 6B is a fourth embodiment of the present invention which modulo 2 adds the data field to a UE ID field padded with leading zeros to create a mask.
FIG. 6C is the data burst transmitted by the embodiments of FIG. 6A and 6B including a data field and a CRC field.
FIG. 7A is a fifth embodiment of the present invention which modulo 2 adds the data field to a UE ID field repeated and padded a truncated UE ID in the trailing bits.
FIG. 7B is a sixth embodiment of the present invention which modulo 2 adds the data field to a UE ID field repeated and padded a truncated UE ID in the leading bits.
FIG. 7C is the data burst transmitted by the embodiments of FIGS. 7A and 7B including a data field and a CRC field.
FIG. 8 is a tabulation of global, subset, subsubset and unique IDs.
FIG. 9 is a flow diagram of the processing of a message in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The presently preferred embodiments are described below with reference to the drawing figures wherein like numerals represent like elements throughout.
Referring to FIG. 1D , a Universal Mobile Telecommunications System (UMTS) network architecture used by the present invention includes a core network (CN), a UMTS Terrestrial Radio Access Network (UTRAN), and a User Equipment (UE). The two general interfaces are the Iu interface, between the UTRAN and the core network, as well as the radio interface Uu, between the UTRAN and the UE. The UTRAN consists of several Radio Network Subsystems (RNS). They can be interconnected by the Iur interface. This interconnection allows core network independent procedures between different RNSs. The RNS is further divided into the Radio Network Controller (RNC) and several base stations (Node-B). The Node-Bs are connected to the RNC by the Iub interface. One Node-B can serve one or multiple cells, and typically serves a plurality of UEs. The UTRAN supports both FDD mode and TDD mode on the radio interface. For both modes, the same network architecture and the same protocols are used. Only the physical layer and the air interface Uu are specified separately.
Referring to FIG. 4A , one embodiment of the present invention is shown. In this embodiment, the system 100 utilizes the data for transmission (hereinafter referred to as “data”) from the data field 102 , a CRC generator 104 (which has been initialized to zero), the resulting CRC from the CRC field 106 output from the CRC generator 104 , the UE ID from the UE ID field 108 , a modulo 2, adder 110 and a mask 112 . It should be noted that in this embodiment and all of the embodiments described hereinafter, the number of bits of each field is noted above the field as an example. However, the specific number of bits is exemplary and should not be construed to limit the present invention.
The system 100 receives the data field 102 and inputs the data from the data field 102 into the CRC generator 104 . The CRC generator 104 generates the CRC field 106 and outputs the CRC from the CRC field 106 to a first input of the modulo 2 adder 110 . The UE ID from the UE ID field 108 is output to the second input to the modulo 2, adder 110 . The CRC and UE ID are then modulo 2, added to create a mask 112 .
Preferably, the number of bits of the UE ID field 108 (M bits) is the same as the number of bits of the CRC field 106 (N bits). If M=N, then the UE ID may be directly modulo 2, added to the CRC as shown in FIG. 4A . However, if M and N are not equal, then an interim step is necessary to make them equal. If M<N, then the UE ID is padded with either leading xeros or trailing zeros to be equal in length to the CRC. This “padded UE ID” is N modulo 2, added to the CRC 106 . If M>N, then the least significant M−N bits are truncated from the UE ID. The truncated UE ID is then modulo 2, added to the CRC.
Referring to FIG. 4B , the mask 112 that is generated is appended to the data field 102 for transmission.
Referring to FIG. 5A , a second embodiment of the present invention is shown. In this embodiment, the system 200 utilizes the data from the data field 202 , a CRC generator 204 , the UE ID from the UE ID field 208 , and the resulting CRC field 212 . The system 200 receives the data field 202 and outputs the data from data field 202 into the CRC generator 204 . The CRC generator 204 is the same type of generator as the CRC generator 104 from FIG. 4A , except that the CRC generator 204 is initialized with the UE ID from the UE ID field 208 . This initialization is illustrated by the dotted line in FIG. 5A . As is well known by those of skill in the art, a CRC generator is typically initialized to all zeros, as was the case with the CRC generator 104 shown in FIG. 4A . Accordingly, the CRC generator 204 generates a CRC based upon the input data from the data field 202 and the initialization of the CRC generator 204 with UE ID No modulo 2, addition is required in this embodiment.
Preferably, the number of bits of the UE ID from the UE ID field 208 (M bits) is the same as the size of the CRC generator 204 , although this is not necessary. If the size of the UE ID (M-bits) is less than the size of the CRC generator 204 , then the UE ID may be padded with either leading zeros or trailing zeros to be equal in length to the size of the CRC generator 204 . Alternatively, the value in the UE ID field 208 may be loaded to initialize the CRC generator 204 , and any bit positions not filled by the UE ID would be zero. If the size of the UE ID (M bits) is greater than the size of the CRC generator 204 , then the least significant bits are truncated from the UE ID in order to fit the UE ID to CRC generator 204 . The truncated UE ID is then used to initialize the CRC generator 204 .
Referring to FIG. 5B , the CRC field 212 that is generated is appended to the data field 202 for transmission.
This second embodiment of the present invention utilizing implicit UE ID presents a simplistic, yet robust, alternative since it does not require assembly and disassembly of the UE ID with the SCCH-HS, at the transmitter or the receiver, as required by UE-specific CRC methods of the prior art and the first embodiment.
Referring to FIG. 7A , a fifth embodiment of the present invention is shown. In this embodiment, the system 400 utilises the data from the data field 402 , the UE ID from the UE ID field 408 A, a modulo 2, adder 410 , a mask 411 , a CRC generator 404 and the resulting CRC field 412 . The system 400 receives the data field 402 and inputs the data from the data field 402 into a first input of the modulo 2, adder 410 . The UE ID from UE ID field 408 A is output to the second input to the modulo 2, adder 410 . The data from the data field 402 and the UE ID from the UE ID field 408 A are modulo 2 added to create a mask 411 . The mask 411 is input into the CRC generator 404 , which generates the CRC field 412 .
In this embodiment, the number of bits of the UE ID field 408 A (M bits) must be the same as the number of bits of the data field 402 in order to perform the modulo 2, addition. If the M is equal to X, then the UE ID from the UE ID field 408 A may be directly modulo 2, added to the data from the data field 402 . Due to the length of the data field 402 , it is not expected that M will be greater than X. However, if thus were to occur, then the least significant bits are truncated from the UE ID field 408 A until the length of the UE ID hold is equal to X. The truncated UE ID is then modulo 2 added to the value from the data field 402 .
Due to the length X of the data field 302 , it is not expected that M will be greater than X. However, if this were to occur, then the least significant M−X bits are truncated from the value in UE ID field 308 A. The truncated UE ID is then modulo 2 added to the data from the data field 302 .
Referring to FIG. 6B , a fourth embodiment of the present invention is shown. In this embodiment, the system 301 operates in the exact same manner as the third embodiment shown in FIG. 6A . The only difference in this embodiment is the method in which the value from the UE ID field 308 B is generated. In this embodiment, the UE ID is padded with X−M leading zeros such that the UE ID from the UE ID field 308 B is equal in length to the data field 302 . This “padded UE ID value” as shown in FIG. 6B , is then modulo 2, added to the data from the data field 302 . If should be noted that the padding may alternatively comprise a combination of leading and trailing zeros (not shown) in order to make the UE ID the same length as the data field.
Referring to FIG. 6C , the CRC field 312 that is generated from the system 300 of the third embodiment shown in FIG. 6A , or the CRC 314 that is generated from the system 301 of the fourth embodiment shown in FIG. 6B , is appended to the data field 302 for transmission. Accordingly, either type of CRC field 312 , 314 may be used and appended onto the data field 302 .
Referring to FIG. 7A , a fifth embodiment of the present invention is shown. In this embodiment, the system 400 utilizes the data from the data field 402 , the UE ID from the UE ID field 408 A, a modulo 2, adder 410 , a mask 411 , a CRC generator 404 and the resulting CRC field 412 . The system 400 receives the data field 402 and inputs the data from the data field 302 into a first input of the modulo 2, adder 410 . The UE ID from UE ID field 408 A is output to the second input to the modulo 2, adder 410 . The data from the data field 402 and the UE ID from the UE ID field 408 A are modulo 2 added to create a mask 411 . The mask 411 is input into the CRC generator 404 , which generates the CRC field 412 .
In this embodiment, the number of bits of the UE ID field 408 A (M bits) must be the same as the number of bits of the data field 402 in order to perform the modulo 2, addition. If the M is equal to X, then the UE ID from the UE ID field 408 A may be directly modulo 2, added to the data from the data field 402 . Due to the length of the data field 302 , it is not expected that M will be greater than X. However, if this were to occur, then the least significant bits are truncated from the UE ID field 408 A until the length of the UE ID field is equal to X. The truncated UE ID is the modulo 2 added to the value from the data field 402 .
If the length of the UE ID is shorter than the data field 402 , then a “composite UE ID” is created such that the value from the UE ID field 408 A is equal to X. The composite UE ID is created by repeating the UE ID as many times as it will fit within an X-bit field, then filling in the remaining trailing bits with a truncated UE ID. This is represented in the UE ID field 408 A in FIG. 7A . The composite UE ID is then modulo 2, added to the data from the data field 402 .
Referring to FIG. 7B , a sixth embodiment of the present invention is shown. The system 401 of this embodiment operates in the same manner as the fifth embodiment shown in FIG. 7A . The only difference in this embodiment is the value from the UE ID field 408 B. Although the composite UE ID created in the same manner as in FIG. 7A , the truncated UE ID portion is added as leading bits, as opposed to the trailing bits in the UE ID field 408 A shown in FIG. 7A . It should be noted that the truncated UE ID “padding” may include a combination of leading and trailing truncated bits in order in make the UE ID the same length as the data field 402 .
Referring to FIG. 7C , the CRC field 412 that is generated from either the system 400 of the fifth embodiment shown in FIG. 7A , or the CRC field 414 that is generated from the system 401 of the sixth embodiment shown in FIG. 7B , is appended to the data field 402 for transmission. Accordingly, either type of CRC field 412 , 414 may be used and appended onto the data field 402 .
It should be noted that all of the above-described embodiments can be used to support multiple identities (IDs). A UE may be required to process messages addressed at several levels: 1) the UE's unique ID. 2) an ID corresponding in a subset or group of UEs, where the UE belongs to the subset; or 3) a broadcast (global ID) corresponding to all UEs in the system. For example, as shown in FIG. 8 , UE ID 12, has been highlighted to indicate that it will able to receive and process IDs at four different levels: 1) the UE-specific ID (#12); 2) subsubset C ID; 3) subset 2, ID; and 4) global ID. It should also be noted that alternate group identifications A-E, may also be created such that a different group of UEs may be included. For example, group B will include all of the UEs identified next to group B which include UE numbers 2, 7, 12, 17, 22, and 27. Additionally, any group or subgroup may be created by specifically identifying individual UEs as desired by a user.
To support this requirement, the transmitter generates the CRC as described above with each of the embodiments. At the receiver, the UE processes the message and generates the expected CRC, without the ID-based modification. The UE processor then modulo 2, adds the received CRC to the calculated CRC. The resultant output is the transmitted ID, which can be any one of the IDs described above. If the ID is none of these, then the UE discards the transmission.
In accordance with the present invention, using the CRC code of the length N, the undetected error probability on the identified SCCH-HS approaches 2 −n . Using a 24-bit CRC to protect data transmitted on HS-DSCH, a 16-bit CRC to protect control information transmitted on SCCH-HS, and assuming 10 −3 , false acceptance probability of HI bits by an unintended UE, the embodiments in accordance with the present invention hereinbefore described will provide the probability of the false acceptances as follows:
P fa =P fa HI×P fa H×P SD Equation (1)
where P fa , is the probability of a false acceptance; P fa HI is the probability of a false acceptance of HI; P fa H is the probability of a false acceptance of SCCH-HS; and P SD , is the probability of a successful detection of HS-DSCH (P SD ).
Using the above identified values for the present example with Equation (1):
P fs =10 −3 ×2 −16 ×2 −24 =9.1×10 −16
The reliability computation indicates that for the same length CRC, the probability of a user passing erroneous data up to a higher layer, will be extremely low.
Referring to FIG. 9 , the flow diagram illustrates a method for processing downlink messages between a node B and a UE in accordance with the present invention. This method provides a general overview and should not be interpreted as a comprehensive description of all of the detailed medium access control (MAC) layer and physical layer signaling required for processing a message, (i.e., a data packet). The code B first generates a downlink control message in the MAC layer (step 1 ) and then forwards the message and the UE ID to the physical layer (step 2 ). The physical layer generates the CRC and applies the UE ID for forwarding with the message (step 3 ) as a data burst. The message is then transmitted from the node B to the UE (step 4 ). At the physical layer, the UE ID and the CRC are checked to determine if they are correct (step 5 ). If so, the message is forwarded to the MAC layer (step 6 ) which then further processes the message (step 7 ).
It should be noted that step 6 in FIG. 9 includes an additional signal between the physical layer and the MAC layer, which comprises a control message that indicates the CRC/UE ID is valid. However, this is an optional step. In the preferred embodiment, only valid messages will be forwarded from the physical layer to the MAC layer. Accordingly, in the preferred embodiment, the MAC layer will assume that any message that is forwarded to the MAC is valid. In the alternative embodiment, the additional CRC/UE ID valid signaling will be forwarded along with the message as an additional confirmation.
The present invention has the advantage of eliminating separate processing steps for the UE ID and the CRC. When the two fields are combined as hereinbefore described, the UE will not further process any message until both the CRC and the UE ID (or other type of ID shown in FIG. 8 ) are correct.
While the present invention has been described in terms of the preferred embodiment, other variations, which are within the scope of the invention, as outlined in the claims below will be apparent to those skilled in the art. | Embodiments include a method and apparatus for processing a downlink shared channel. In one embodiment, a Node-B includes circuitry configured to process control information for a user equipment (UE) and to produce an N bit cyclic redundancy check (CRC) associated with the control information. The Node-B includes circuitry configured to modulo 2 add the N bit CRC with an N bit UE identity to produce an N bit field, wherein the UE identity is any one of a plurality of UE identities associated with the UE. The Node-B includes circuitry configured to transmit a wireless signal of a control channel, wherein the wireless signal comprises the N bit field and the control information. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is based on, and claims priority from, Korean Application Number 10-2007-0130036 filed Dec. 13, 2007, the entire contents of which application is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an airbag that is used as a safety device in a vehicle, particularly an airbag cushion including multiple chambers inside.
2. Description of Related Art
An airbag cushion provided at the driver seat or the passenger seat generally has one chamber and a tether in the chamber to control the front-to-back size of the chamber.
An airbag cushion having this configuration expands by high-pressure inflator gas toward a passenger. The expansion speed is so fast that the passenger may be injured, particularly in the face and neck.
Further, an airbag cushion having one chamber as described above is insufficient to protect the passenger because it cannot expand sufficiently rapidly between the passenger and the steering wheel.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
BRIEF SUMMARY OF THE INVENTION
Various embodiments of the present invention provide for a structure of an airbag cushion with multi-chamber that allows an airbag to expand in a predetermined order at a predetermined speed to optimally protect a passenger by setting the expansion order and speed of the chambers different, such that the airbag can rapidly expand between the passenger and the steering wheel, without hitting and hurting the passenger.
One aspect of the present invention provides an airbag cushion with multiple chambers including an inner chamber that is connected to directly receive inflation gas from an inflator, and/or a first chamber and a second chamber that are connected to the inner chamber to respectively receive the inflation gas from the inner chamber, wherein at least one vent hole is formed on the boundary of the inner chamber such that the amount of inflation gas supplied to the second chamber is larger than the amount of inflation gas supplied to the first chamber.
In various embodiments, a first inner vent hole and a second inner vent hole may be formed on the boundary of the inner chamber, the first vent hole allowing inflation gas to pass into the first chamber and the second vent hole allowing inflation gas to pass into the second chamber.
In some aspects, the airbag cushion further may include a diffuser and an airbag module housing including an inflator, wherein the inner chamber, the first chamber, and the second chamber are formed by a cushion sheet making a single closed surface, the inner chamber is formed by a portion of the cushion sheet recessed from the front portion of the airbag cushion and toward the inside of the airbag cushion, the portion of the cushion sheet that overlaps to form the inner chamber forms a tether, the diffuser is located inside the inner chamber, and/or the diffuser passes through the cushion sheet at least two times and is connected to the inflator.
In various embodiments, at least one outer vent hole facing the outside of the airbag cushion may be formed on the boundary of the first chamber, the second inner vent hole may be larger than the first inner vent hole, the first chamber may be positioned at the upper portion of the airbag cushion, the second chamber may be positioned at the lower portion of the airbag cushion, and/or the inner chamber may be positioned at the center of the airbag cushion.
In various embodiments, a cross-section of the inner chamber may be rectangular and cross the center of a circle constructed by the outline of the airbag cushion sheet, when seen from the opposite side of the inflator.
In various embodiments, a cross-section of the inner chamber may have the shape of two trapezoids whose shorter bases coincide, when seen from the opposite side of the inflator.
In various embodiments, a cross-section of the inner chamber may have the shape of two trapezoids whose longer bases coincide, when seen from the opposite side of the inflator.
In various embodiments, the cushion sheet may be formed by attaching a first cushion sheet forming the front portion of the airbag cushion and the inner chamber to a second cushion sheet forming the rear portion of the airbag cushion, the inner chamber runs from one edge of the first cushion sheet to the opposite edge;
and at least one of the ends of the inner chamber is closed by attaching the first cushion sheet with the second cushion sheet.
In various embodiments, the cushion sheet is formed by combining a first cushion sheet forming the front portion of the airbag cushion and the inner chamber with a second cushion sheet forming the rear portion of the airbag cushion sheet, the inner chamber runs from one edge of the first cushion sheet to the opposite edge, a first end of the inner chamber is closed by sewing the edges of the first cushion sheet defining the first end, and/or an inner vent hole allowing gas to pass to the first chamber and the second chamber is formed by partially sewing closed the second end of the inner chamber.
In various embodiments, the boundary of the inner chamber further includes additional first inner vent holes, second inner vent holes, and a third inner vent hole facing a gap at a portion where the cushion sheet overlaps around the portion where the diffuser is disposed, to supply the inflation gas simultaneously to the first chamber and the second chamber, the first inner vent holes and the second inner vent holes are formed in the same size, and/or the number of the second inner vent holes is larger than the number of the first inner vent holes.
In various embodiments, the first cushion sheet further includes a fourth inner vent hole, first sewing lines, second sewing lines and third sewing lines, a tether is formed by overlapping a portion of the first cushion sheet and sewing together first sewing lines, sewing together second sewing lines and sewing together third sewing lines, an overlapping portion of the first cushion sheet is sewn along the entire length of the inner chamber, the second sewing lines are shorter than the first sewing lines at both ends, are parallel with the first sewing lines and are positioned away from the first sewing lines toward the inner chamber, the third sewing lines run perpendicular to and intersect the second sewing lines and the first sewing lines, and the fourth inner vent hole is surrounded on three sides by the outlines of the first sewing line, the third sewing line, and an edge of the first cushion sheet to supply the inflation gas into the first chamber.
In various embodiments, the first chamber and the second chamber are formed by attaching a first cushion sheet forming the front portion of the airbag cushion and the inner chamber to a second cushion sheet forming the rear portion of the airbag cushion sheet, the inner chamber is formed by an inner cushion that crosses the inside of the airbag cushion while making a closed surface independent from the airbag cushion, and/or at least one of the ends of the inner cushion is attached to a portion where the first cushion sheet is attached to the second cushion sheet.
In various aspects of the present invention an airbag cushion with multiple chambers, includes an inner chamber that is connected to directly receive inflation gas from an inflator, and/or a first chamber and a second chamber that are connected to the inner chamber to respectively receive the inflation gas from the inner chamber, wherein first inner vent holes and second inner vent holes having the same size are formed on the boundary of the inner chamber to supply inflation gas into the first chamber and the second chamber, respectively, the first chamber and the second chamber are disposed at both left and right sides of the airbag cushion, and/or the inner chamber runs from the top to the bottom of the airbag cushion between the first chamber and the second chamber.
In various embodiments, the inner chamber, the first chamber, and the second chamber are formed by attaching a first cushion sheet to a second cushion sheet to form a cushion space therein, the center of the first cushion sheet is recessed away from the outside of the airbag cushion to form the inner chamber such that the cushion space is divided by the inner chamber into the first chamber and the second chamber, the first cushion sheet overlaps between the inner chamber and the first cushion sheet such that the inner chamber is blocked from the outside, the overlapping portion of the first cushion sheet functions as a tether, and/or inflation height of the airbag cushion is adjusted by the length of the inner chamber and the tether, and an outer vent hole facing the outside of the airbag cushion is formed at a portion where the second cushion sheet contacts the inner chamber.
In various aspects of the present invention, an airbag cushion with multiple chambers includes a first cushion sheet and a second cushion sheet attached to form a cushion space therein and two inner chambers are formed by depressing along a first axis crossing the center of the first cushion sheet and then along a second axis crossing the center of the first cushion sheet and running perpendicular to the first axis, wherein the cushion space is divided into four spaces by the two inner chambers perpendicularly crossing each other, the inner chambers are connected to directly receive inflation gas from an inflator, and the four spaces divided by the two inner chambers receive the inflation gas from the inner chambers.
In various aspects, an airbag cushion has multiple chambers of which the expansion order and speed are controlled. The airbag cushion can expand in a predetermined order at a predetermined speed to optimally protect a passenger. Therefore, the airbag cushion can rapidly expand between the steering wheel and the passenger, without injuring the passenger.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an exemplary airbag cushion with multiple chambers according to the present invention.
FIG. 2 is a development view of an exemplary first cushion sheet of the airbag cushion shown in FIG. 1 .
FIG. 3 is a view showing the first cushion sheet shown in FIG. 2 , which is sewn.
FIG. 4 is a left side view of FIG. 3 .
FIG. 5 is a development view of an exemplary second cushion sheet of the airbag cushion shown in FIG. 1 .
FIG. 6 is a view showing the airbag cushion shown in FIG. 1 , facing the first cushion sheet.
FIG. 7 is a view illustrating folding the airbag cushion shown in FIG. 6 to mount the airbag cushion.
FIG. 8 is a view sequentially illustrating expansion of the airbag cushion shown in FIG. 1 .
FIG. 9 is a view showing an exemplary modification of the airbag cushion shown in FIG. 1 , in which a second chamber is increased in size.
FIG. 10 is a view showing an exemplary modification of the airbag cushion shown in FIG. 1 , in which a first chamber is increased in size.
FIG. 11 is a view of the airbag cushion according to various aspects of the present invention.
FIG. 12 is a view illustrating exemplary folding the airbag cushion shown in FIG. 11 to mount the airbag cushion.
FIGS. 13 to 17 are views of exemplary airbag cushions according to the present invention.
FIG. 18 is a development view of a first cushion sheet shown in FIG. 17 .
FIGS. 19 and 20 are views of exemplary airbag cushions according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
Referring to FIGS. 1 to 7 , according to various embodiments of the present invention, a first cushion sheet 1 and a second cushion sheet 3 are attached to form a cushion space 5 inside. An inner chamber 7 is recessed from the outside to the inside at the center portion of the first cushion sheet such that cushion space 5 is divided by inner chamber 7 .
First cushion sheet 1 attached to second cushion sheet 3 forms a cushion sheet having a single closed surface. First cushion sheet 1 is disposed at the front portion of the airbag cushion, toward a passenger, and second cushion sheet 3 is disposed at the opposite side, toward an inflator. The edges of first cushion sheet 1 and second cushion sheet 3 are sewn to form the outline of the airbag cushion.
First cushion sheet 1 is plied causing two portions of the sheet to overlap, forming inner chamber 7 , which is isolated from the outside. The overlapping portion of first cushion sheet 1 functions as a tether 9 .
The overlapping portion of first cushion sheet 1 that forms tether 9 is sewn at least from inner chamber 7 and the outer surface of cushion sheet 1 , respectively.
It may be possible to sew other portions to increase the strength of tether 9 and to change the length of tether 9 , the size and shape of inner chamber 7 and expansion characteristics of airbag cushion 11 .
Cushion space 5 is divided into a first chamber 13 and a second chamber 15 by inner chamber 7 . First inner vent holes 17 are formed to connect inner chamber 7 with first chamber 13 , that is, the inner vent holes lie on the boundary between inner chamber 7 and first chamber 13 . Second inner vent holes 19 are formed to connect inner chamber 7 with second chamber 15 . Outer vent holes 21 that are open to the outside are formed at the boundary of first chamber 13 .
In various embodiments, a second inner vent hole 19 is larger than a first inner vent hole 17 and inner chamber 7 is formed in a rectangular shape, which crosses the center of a circle constructed by the outline of first cushion sheet 1 , when seen from first cushion sheet 1 .
Further, in various embodiments, cushion space 5 is divided into similarly sized sections by inner chamber 7 such that first chamber 13 is disposed at the upper portion of airbag cushion 11 and second chamber 15 is disposed at the lower portion of airbag cushion 11 .
In various embodiments, dividing cushion space 5 by an inner chamber does not mean that different chambers of cushion space 5 are completely sealed off from each other. Cushion space 5 thus can be considered as a large volume having at least two sections that are not substantially isolated from each other. That is, as shown in FIG. 1 , first chamber 13 and second chamber 15 of cushion space 5 divided by inner chamber 7 are connected such that gas can practically flow through a gap between inner chamber 7 and second cushion sheet 3 .
In various embodiments, first cushion sheet 1 forms the front portion of airbag cushion 11 , facing a passenger, and second cushion sheet 3 forms the rear portion of airbag cushion 11 , facing an inflator 23 .
In various embodiments, it may be possible that first cushion sheet 1 forms the rear portion of airbag cushion 11 , facing inflator 23 , and second cushion sheet 3 forms the front portion of airbag cushion 1 , facing a passenger.
A diffuser 25 , disposed inside inner chamber 7 , is connected with inflator 23 , which is fastened to an airbag module housing 27 , through first cushion sheet 1 and second cushion sheet 3 .
FIG. 2 is a development view of first cushion sheet 1 , in which fixing bolt holes 29 for fastening diffuser 25 to airbag module housing 27 and an inflator connection hole 31 for connecting diffuser 25 to inflator 23 are formed at the center portion. Further, first inner vent holes 17 are formed above fixing bolt holes 29 , second inner vent holes 19 are formed under fixing bolt holes 29 , and sewing lines for forming tether 9 lie above first inner vent hole 17 and under second inner vent holes 19 .
The shape shown in FIG. 3 is obtained by sewing corresponding sewing lines (a), (b), respectively. The length between the two lines (a) and (b) is the tether's length as shown in FIG. 4 and consequently the portion between the sewing lines (a) forms inner chamber 7 .
FIG. 5 is a development view of second cushion sheet 3 that can be connected with first cushion sheet 1 to form cushion space 5 , in which fixing bolt holes 29 and inflator connection hole 31 that are connected with fixing bolt holes 29 and inflator connection hole 31 of first cushion sheet 1 are formed at the center portion. For reference, fixing bolt holes 29 and inflator connection hole 31 are referred by the same names and reference numbers as those of first cushion sheet 1 .
Outer vent holes 21 are formed above fixing bolt holes 29 and inflator connection hole 31 of second cushion sheet 3 .
Airbag cushion 11 shown in FIG. 6 is completed by overlapping first cushion sheet 1 and second cushion sheet 3 and then sewing them around the edge.
Inner chamber 7 runs from one edge of the first cushion sheet to the opposite edge. Both ends inner chamber 7 are closed where first cushion sheet 1 and second cushion sheet 3 are connected.
Airbag cushion 11 formed as shown in FIG. 6 is folded as shown in FIG. 7 and then mounted.
That is, as shown at the upper portion of FIG. 7 , airbag cushion 11 is folded in a rectangular shape having substantially the same size as inner chamber 7 by pushing the upper portion of first chamber 13 to the center portion between inner chamber 7 and first cushion sheet 1 and the lower portion of second chamber 15 to the center portion between inner chamber 7 and first cushion sheet 1 , and then the rectangle is folded or rolled at both ends into a substantially square shape to be mounted.
The operation of the airbag cushion having the above configuration according to various embodiments of the present invention is described hereafter with reference to FIG. 8 .
As inflator 23 is actuated, inner chamber 7 directly connected to inflator 23 first expands as shown on the left of FIG. 8 .
Inflation gas of inner chamber 7 is supplied into first chamber 13 and second chamber 15 through first inner vent holes 17 and second inner vent holes 19 respectively, but because second inner vent holes 19 are larger than first inner vent holes 17 , second chamber 15 fully expands first as shown in the center of FIG. 8 , followed by full expansion of first chamber 13 as shown on the right of FIG. 8 .
That is, when airbag cushion 11 is mounted in the steering wheel, after inner chamber 7 expands, second chamber 15 at the lower portion fully expands first between the steering wheel and the driver's chest to effectively prevent impact between the steering wheel and the driver. Further, since airbag cushion 11 is controlled such that the parts sequentially expand as described above, it is possible to maximize the protection performance of the airbag.
Cushion space 5 may be divided into sections having different sizes. FIG. 9 shows an example in which second chamber 15 at the lower potion is larger than first chamber 13 at the upper portion. FIG. 10 shows another example in which first chamber 13 at the upper portion is larger than second chamber 15 at the lower portion.
The structure shown in FIG. 9 may be useful to increase protection of the chest, for example, in instances where a passenger does not fasten his or her seat belt. The structure shown in FIG. 10 may be useful to increase protection of the head, for example, in instances where a passenger does fasten his or her seat belt.
According to various embodiments of the present invention such as shown in FIG. 11 , second chamber 15 also has outer vent holes 21 that are open to the outside, first inner vent hole 17 is the same in size as second inner vent hole 19 , first chamber 13 and second chamber 15 are disposed at the left and right sides of airbag cushion 11 , respectively, and the length of inner chamber 7 runs from the top of the airbag cushion to the bottom.
That is, in various embodiments of the present invention, the length of inner chamber 7 runs from the top of the airbag cushion to the bottom, and first chamber 13 and second chamber 15 are disposed to the left and to the right of inner chamber 7 .
Airbag cushion 11 having this configuration is also folded in a substantially square shape to be mounted, by first pushing both sides of first chamber 13 and second chamber 15 to the center portion between inner chamber 7 and first cushion sheet 1 , in a rectangular shape that is similar to inner chamber 7 as shown at the left in FIG. 12 and then folding or rolling the upper and lower sides of the rectangle to the center portion, as shown at the right in FIG. 12 .
As airbag cushion 11 expands, inner chamber 7 first expands such that the chest-sided portion and the upper portion thereof expand, and then first chamber 13 and second chamber 15 at the left and right sides simultaneously expand.
FIG. 13 shows that in various embodiments, cushion space 5 is divided into first chamber 13 and second chamber 15 by inner chamber 7 , first inner vent hole 17 is formed to connect inner chamber 7 with first chamber 13 , second inner vent hole 19 is formed to connect inner chamber 7 with second chamber 15 , and outer vent hole 21 that is open to the outside is formed where second cushion sheet 3 contacts with inner chamber 7 .
That is, various embodiments such as shown in FIG. 13 may be similar to other aspects such as shown in FIG. 11 , except that outer vent hole 21 is positioned where second cushion sheet 3 contacts inner chamber 7 , i.e. behind inner chamber 7 .
According to various embodiments, first inner vent hole 17 is the same in size as second inner vent hole 19 , first chamber 13 and second chamber 15 are disposed at the left and right sides of airbag cushion 11 , respectively, and the length of inner chamber 7 runs from the top of the airbag cushion to the bottom.
Therefore, in the early stages of expansion, outer vent hole 21 is obstructed by the wall of inner chamber 7 , such that discharge of inflation gas out of the airbag cushion is reduced. Further, the inflator gas is allowed to discharge toward outside when the internal pressure of airbag cushion is increased by impact with passenger. Therefore, it is expected that airbag cushion 11 will be able to more rapidly expand in various embodiments of the present invention.
According to various aspects, the length of inner chamber 7 runs from top to bottom, at least one end of inner chamber 7 is independently closed, regardless of how first cushion sheet 1 and second cushion sheet 3 are connected.
In FIG. 14 , both ends of inner chamber 7 are independently closed, such as by sewing, regardless of how first cushion sheet 1 and second cushion sheet 3 are connected. That is, both longitudinal ends of inner chamber 7 may be closed by sewing regardless of first cushion sheet 1 and second cushion sheet 3 .
Further, according to various embodiments of the present invention, at least one end of longitudinal overlapped ends of the first cushion forming the inner chamber may be independently closed, regardless of the portion where the first cushion sheet and the second cushion sheet are connected. In various embodiments it is thus possible to form an inner vent hole that is communicated with cushion space 5 by adjusting the sewing length. That is, by partially sewing the portion where the space of inner chamber 7 is separated from the cushion chambers such that inner chamber 7 is partially open, the opened portion can be used as an inner vent hole.
FIG. 15 shows various aspects of the present invention, in which inner chamber 7 has a cross-section delineated by two trapezoids coinciding along their shorter bases such that the center portion of a circle constructed by the outline of first cushion sheet 1 is recessed inside, when seen from first cushion sheet 1 .
FIG. 16 shows another embodiment of the present invention, in which inner chamber 7 has a cross section delineated by two trapezoids coinciding along their longer bases such that the center portion of a circle constructed by the outline of first cushion sheet 1 protrudes outside, when seen from first cushion sheet 1 .
That is, as shown in FIGS. 15 and 16 , it is possible to change expansion characteristics of the airbag cushion by changing the shape of the cross-section of inner chamber 7 .
FIGS. 17 and 18 show various embodiments of the present invention in which the center portion of first cushion sheet 1 is first recessed and overlaps itself and then is additionally vertically recessed and overlaps itself such that inner chambers 7 recessed from the outside to the inside vertically cross each other. That is, first cushion sheet 1 is depressed along a first axis crossing the center of the sheet and then along a second axis crossing the center of the sheet and running perpendicular to the first axis. Therefore, cushion space 5 is divided into four sections by two inner chambers 7 crossing each other.
FIG. 18 is a development view, in which inner chamber 7 is formed inside by contacting the parallel edges of quarter-circles 44 with each other so as to form a full circle centered on the center of first cushion sheet 1 . Thereafter, the airbag cushion shown in FIG. 17 is obtained by sewing second cushion sheet 3 with the edges.
Outer vent holes 21 formed through second cushion sheet 3 can be seen in FIG. 17 .
Further, FIG. 19 shows that various aspects in which inner chamber 7 is not formed by first cushion sheet 1 or second cushion sheet 3 , and first cushion sheet 1 and second cushion sheet 3 are connected to form cushion space 5 inside. An inner cushion 33 is disposed inside cushion space 5 to form an independent inner chamber 7 inside cushion space 5 .
At least one of the ends of inner cushion 33 may be connected where first cushion sheet 1 and second cushion sheet 3 are connected, and both ends are connected by sewing in FIG. 19 .
FIG. 20 shows various aspects of the present invention in which a first cushion sheet 1 and a second cushion sheet 3 are developed. First cushion sheet 1 is folded and sewn to form an inner chamber 7 and the edge is connected with second cushion sheet 3 . Accordingly, an airbag cushion, which has inner chamber 7 directly receiving inflation gas from inflator 23 and first chamber 13 and a second chamber 15 receiving inflation gas through first inner vent holes 17 and second inner vent holes 19 from inner chamber 7 , can be achieved.
Third inner vent holes 35 facing the gap between inner chamber 7 and second cushion sheet 3 are further formed in inner chamber 7 to supply inflation gas simultaneously to first chamber 13 and second chamber 15 . First inner vent holes 17 and second inner vent holes 19 are formed in the same size, and the number of second inner vent holes 19 is larger than that of first inner vent holes 17 .
Therefore, the chambers of the airbag cushion inflate in the following order: inner chamber 7 , second chamber 15 , and first chamber 13 . Second chamber 15 is disposed at the lower portion of the airbag cushion and to relatively quickly absorb the shock due to contact with a passenger's chest and abdomen and first chamber 13 gradually and smoothly absorbs the shock due to contact with the passenger's head and neck.
The part functioning as tether 9 of the first cushion sheet 1 is formed by first sewing lines 37 where the folded portion of first cushion sheet 1 is sewn along the entire length of inner chamber 7 . Second sewing lines 39 , which are shorter than first sewing lines 37 , run parallel to and are positioned away from first sewing lines 37 and toward the inflator connection hole 31 . Third sewing lines 41 run perpendicularly between second sewing lines 39 and first sewing lines 37 .
That is, first sewing line 37 , second sewing line 39 , and third sewing line 41 form a hat shape. The upper portion of the hat faces the center of first cushion sheet 1 . The hat shapes are aligned and sewn.
Fourth inner vent holes 43 are further formed at a portion of inner chamber 7 of which three sides are surrounded by the outlines of first sewing line 37 , third sewing line 41 , and the edge of first cushion sheet 1 to supply the inflation gas into first chamber 13 .
Fourth inner vent holes 43 allow the pressure of the inflation gas to be directly transmitted to both sides, not the center portion, of first chamber 13 , such that the pressure to a passenger's head and neck at the center portion of first chamber 13 is relatively smaller than the pressure at the sides. Accordingly, it is possible to increase shock-absorbing effect.
As described above, the basic operation of the various embodiments shown in FIGS. 11 to 20 may not be different from that of the embodiments shown in FIGS. 1 to 8 . That is, in various embodiments, airbag cushion 11 is divided into a plurality of chambers by forming inner chamber 7 in airbag cushion 11 . Thus, the order and rate of expansion of the chambers can be controlled, such that as airbag cushion 11 expands, it is possible to control the manner in which a passenger contacts the airbag cushion. Further, it is possible to prevent or reduce injury due to impact on the passenger's body.
For convenience in explanation and accurate definition in the appended claims and the specification, the terms “upper,” “lower,” “front,” “rear,” “inside,” “outside,” “left,” “right” and the like are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. | An airbag cushion has multiple chambers of which the expansion order and speed are controlled. The airbag cushion can expand in a predetermined order at a predetermined speed to optimally protect a passenger. Therefore, the airbag cushion can rapidly expand between the steering wheel and the passenger, without injuring the passenger. | 1 |
This application is a continuation of application Ser. No. 600,396 filed Apr. 16, 1984, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a recording apparatus using ink to effect recording, such as a pen recorder or an ink jet recording apparatus, and to a liquid filter suitable for use with such a recording apparatus.
2. Description of the Prior Art
Generally, in a recording apparatus using ink to effect recording, such as a pen recorder or an ink jet recording apparatus, a filter is provided in the intermediate portion of an ink supply path for supplying ink from an ink container to a recording head. FIG. 1 of the accompanying drawings shows an ink jet recording apparatus according to the prior art. In FIG. 1, reference numeral 1 designates a cylindrical piezo element which may receive and compressively deform an electrical pulse and eject ink droplets 3 from an orifice 2. Reference numeral 4 designates a hard glass tube having the orifice 2 at the tip end thereof and further having the piezo element 1 wound thereon. Reference numeral 5 denotes a lead for transmitting the electrical pulse to the piezo element 1. One end of the lead 5 is connected to the surface electrode of the cylindrical piezo element 1 and the other end of the lead 5 is connected to an inner electrode through plating provided on the end surface of the element. Reference numeral 6 designates a flexible tube connected to an ink container, not shown, and also connected to the open end of the glass tube 4. Reference numeral 7 denotes a liquid filter forced into the tube 6. In the ink jet recording apparatus of the above-described construction, it is desirable that the filter 7 perform the following functions:
1. Block the entry of dust which can clog the nozzle whose opening diameter is several tens of μm;
2. Supply sufficient amount of ink to the nozzle;
3. Prevent bubbles created on the ink container side from entering the nozzle;
4. Prevent rearward escape of the pressure which provides the power when the piezo element 1 is deformed to fly ink droplets; and
5. Absorb any pressure fluctuations created in the nozzle and maintain the meniscus in the orifice in a stable condition when the recording head is mounted on a carriage and is reciprocally moved to right and left.
A particularly important function is preventing the entry of bubbles into the nozzle. If bubbles should enter the pressure chamber, which is a space in the glass tube surrounded by the piezo element, the efficiency of the piezo element 1 will be significantly decreased due to the great compressiveness of the bubbles. Also, if bubbles arrive at the vicinity of the orifice 2, the direction of flight of ink droplets will change or minute droplets will be created and cause unsatisfactory printing and, in the worst case, jetting of ink will become impossible.
Accordingly, preventing the entry of bubbles into the pressure chamber is indispensable for stable operation of the ink jet recording apparatus.
In contrast, the filter 7 heretofore used comprises particles 8 of polyethylene integrally shaped by sintering as shown in FIGS. 2A and 2B of the accompanying drawings, and suffers from various problems.
First, since this filter comprises hardened small particles, some of the particles may fall off when the filter is mounted. This means that the filter for preventing the entry of dust itself becomes a source of particles that can clog the recording head and thus, the manufacturing process used to make the filters must be strictly controlled.
Also, ink 9 tries to fill the spaces between the particles 8 but, an acute-angle portion 10 of 30° or less is unavoidably created between the particles and ink cannot enter such portion. If such an acute-angle portion 10 is present, it means that the filter for preventing the entry of bubbles itself contains bubbles therein. Such bubbles usually cannot be removed even if they are sucked from outside and, as the recording apparatus is used for many years, they are gradually discharged and enter the orifice.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above-noted problems at a stroke.
That is, it is an object of the present invention to provide a recording apparatus which can accomplish very stable recording without creating any bubbles which may adversely affect recording and without the possibility of a part of the liquid filter coming loose to clog the recording head, and a liquid filter suitable for use with the recording apparatus.
It is also an object of the present invention to provide a recording apparatus in which ink flows out from the end of a recording head to effect recording on a recording medium and in a portion of an ink supply path leading from an ink container to the recording head, there is provided a filter substantially parallel to the direction of liquid flow in the supply path and having a number of minute communication bores.
It is a further object of the present invention to provide a lotus root-like or honeycomb-like liquid filter mounted in the intermediate portion of the ink supply path and substantially parallel to the direction of liquid flow in the supply path and having a number of minute communication bores.
The invention will become fully apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a recording head according to the prior art.
FIGS. 2A and 2B are enlarged views of a filter.
FIG. 3 is a cross-sectional view of an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 4 illustrates a filter used in the embodiment.
FIG. 5 illustrates the manufacturing process of the filter of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 3 shows an ink jet recording apparatus according to an embodiment of the present invention.
In FIG. 3, reference numeral 11 designates a recording head for discharging ink by the action of a piezo element to effect recording by ink similarly to the recording head shown in FIG. 1, reference numeral 12 denotes recording paper on which recording by ink is effected, reference numeral 13 designates a carriage for reciprocating the recording head, reference numeral 14 denotes a sub-ink tank for supplying ink to the recording head, reference numeral 15 designates a supply pipe for supplying ink from the sub-ink tank 14 to the recording head, and reference numeral 16 denotes a filter for cutting dust, bubbles, pressure, etc.
The recording head 11 and the sub-ink tank 14 for supplying ink to the recording head are integrally provided on the reciprocally movable carriage 13. The sub-ink tank 14 is connected to a main ink tank 18 by a reciprocally movable ink supply tube 17. Any fluctuation of pressure caused by the inertia of the ink in the ink supply tube 17 vibrated by reciprocal movement of the carriage 13 is absorbed by the air layer 19 and the filter 16 in the sub-ink tank 14.
However, if the air layer 19 in the sub-ink tank 14 becomes pressurized by temperature rise or ambient pressure reduction, the pressure of the air layer will be propagated to the recording head 11 and normal discharge of ink will become impossible.
Therefore, the main ink tank 18 is formed into a flat and thin type flexible bag structure so as to absorb any variation in pressure caused by the air layer 19 in the sub-ink tank 14. That is, the ink jet recording apparatus of the type receiving the supply of ink from the fixed main ink tank 18 through the movable supply tube 17 and effecting recording by reciprocally moving on the carriage at a high speed requires a sub-ink tank having therein an air layer for absorbing any momentary pressure fluctuation caused by the inertia of the ink in the supply tube 17 and further requires the absorption of the relatively slow pressure fluctuation caused by the air layer being expanded by the temperature rise or the like in the apparatus.
The load resistance of the recording head 11 and the filter 16 is much greater than the load of the supply tube 17 and the main ink tank 18 of the flat and thin type flexible bag structure and therefore, the ink in the sub-ink tank 14 readily moves into the main ink tank 18, whereby the pressure in the sub-ink tank 14 becomes balanced. The diameter of the discharge orifice of the recording head is usually 100 μm or less.
The absorbing effect of the momentary pressure fluctuation is greater as the air layer 19 in the sub-ink tank 14 becomes greater in quantity. On the other hand, however, the secondary effect of the air layer being expanded or contracted by a temperature change becomes greater and the air layer usually has a volume of the order of 0.3 to 0.8 cc.
However, even in such a construction, if air bubbles lie sporadically in the ink supply tube 7, ink will not move smoothly. To eliminate such inconvenience, in the present embodiment, a communication opening to the atmosphere is provided in the sub-ink tank 14 by a thin tube 20 having a small inside diameter. Accordingly, this structure forms not a completely sealed system but a quasi-sealed system. The outer end 20A of the thin tube 20 is utilized to initially fill the sub-ink tank 14, and the level of the ink in the sub-ink tank 14 reaches the inner end 20B of the thin tube 20 and the interior of the tube is also filled with ink.
The ink is exclusively for use for ink jet and the components thereof include a solvent such as polyethylene glycol which is very hard to evaporate and therefore, the ink in the thin tube 20 does not completely evaporate throughout a long period of time and by the surface tension and viscosity thereof, it cuts off the communication between the air layer 19 in the sub-ink tank 14 and the atmosphere to thereby form a quasi-sealed system.
Reference numeral 21 designates the magnetic yoke of a linear motor which serves also as a sliding shaft, reference numeral 22 denotes a frame and magnetic yoke, and reference numeral 23 designates a permanent magnet. The carriage 13 is reciprocally moved to right and left on the magnetic yoke 21 by the Fleming's force acting between it and a coil, not shown.
The supply of ink from the main ink tank 18 to the recording head 11 is automatically accomplished by the ink being sucked from the main ink tank 18 due to the air layer 19 in the sub-ink tank 14 being reduced in pressure by the decrease in the ink in the sub-ink tank 14 caused by the continuous surface tension or capillary phenomenon of the ink or injection of the ink.
The filter 16 has a structure like a lotus root or honeycomb in cross-section, as shown in FIG. 4. This filter 16 is provided by bundling several hundred glass fiber tubes 6a each having a communication bore 6b having a diameter d of the order of 10-50 μm, as shown in FIG. 5, heat-compressing the bundle to eliminate the gaps between the fiber tubes and make the fiber tubes into the form of a lotus root or honeycomb, and cutting the honeycomb-like member into a suitable length by a cutter. This filter 16 has 20-800 communication bores per 1 mm 2 , and it is preferable in effectively performing the function as a liquid filter that the relation between the length L and the diameter d of each communication bore be L/d≧10.
Since, as described above, the filter 16 is of a construction in which a number of fiber tubes 6a having minute communication bores 6b have been heat-compressed so as to eliminate the gaps therebetween, it achieves well the function as a filter used in an ink jet recording apparatus, and parts do not separate and create loose particles as has been experienced in the prior art, and it does not have minute gaps having an acute angle of 30° or less which will hold bubbles therein.
The present invention is not restricted to the above-described embodiment, but ceramics having a stronger hydrophilic property may be used as the material of the fiber tubes, for example. Also, the fiber tubes need not always be of a circular cylindrical shape but may be, for example, of a square pillar shape or the like and in this latter case, it is preferable that the length of the largest side of the communication bores of the square pillar-like tubes be of the order of 20-50 μm. This filter may be used anywhere in the ink supply path leading from the ink tank to the recording head. Further, the above-described filter is widely applicable not only to an ink jet recording apparatus but also, for example, to a pen recorder or other recording apparatus for effecting recording by the use of ink.
According to the present invention, as described above, very stable recording becomes possible without creating bubbles which will adversely affect the recording and without the possibility of a part of the apparatus separating and clogging the recording head. | A recording apparatus in which ink flows out from the end of a recording head to effect recording on a recording medium, has in a portion of an ink supply path leading from an ink container to the recording head a filter substantially parallel to the direction of liquid flow in the supply path and having a number of minute communication bores. | 1 |
RELATED APPLICATIONS
The present application is claims priority from Japanese Applications No. 2009-230356, filed Oct. 2, 2009 and No. 2009-250275, filed Oct. 30, 2009, the disclosure of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
This invention concerns a pellicle for lithography used as a dust-fender for masks employed in lithographic printing to manufacture semiconductor devices such as LSI and super LSI as well as liquid crystal display board. Also the invention relates to a method for manufacturing such a pellicle which mainly consists of a frame and a transparent membrane pasted on the frame.
TECHNICAL BACKGROUND OF THE INVENTION
In manufacturing semiconductor devices such as LSI and super-LSI or in manufacturing a liquid crystal display board or the like, a pattern is made by irradiating light to a semiconductor wafer or an original plate for liquid crystal, but if a dust gets to adhere to a photo mask or a reticle (hereinafter merely referred to as a “mask” for simplicity) during the irradiation operation, the dust absorbs light or refracts it, causing deformation of a transferred pattern, roughened edges or black stains on a base, and leads to a problem of damaged dimensions, poor quality, deformed appearance and the like.
Thus, these works are usually performed in a clean room, but it is still difficult to keep the mask clean all the time. Therefore, a pellicle is attached to a surface of the mask as a dust-fender before photo irradiation is carried out. Under such circumstances, foreign substances do not directly adhere to the surface of the mask but only onto the pellicle membrane, which is sufficiently removed from the mask surface, and thus by setting a photo focus on a lithography pattern on the mask, the foreign substances on the pellicle membrane fail to transfer their shadows on the mask and thus no longer become a concern to the image transfer performance.
In general, a pellicle is built up of a pellicle frame, which is an endless frame bar, and a transparent membrane or pellicle film, the latter being tensely pasted to one of two frame faces. The membrane material is selected from cellulose nitrate, cellulose acetate, fluorine-containing polymer and the like, which transmits light (g-ray, i-ray, KrF excimer lasers, ArF excimer lasers, etc.) well, and the pellicle frame is made of aluminum, stainless, polyethylene and the like. A solvent capable of dissolving the pellicle film is applied to one of two frame faces of the pellicle frame and the pellicle film is laid onto it and the solvent is air-dried to complete the adhesion, or an adhesive such as acrylic resin, epoxy resin, fluorine-containing resin or the like is used to adhere the pellicle film onto the frame face (hereinafter this face is called “upper frame face”). The other frame face (hereinafter called “lower frame face”) of the pellicle frame is laid with a pressure-sensitive adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin and the like for attaching the pellicle frame to a mask, and over the pressure-sensitive adhesive layer is laid a separation layer (or releaser) for protecting the pressure-sensitive adhesive layer.
The pellicle is installed in a manner such that the pellicle frame encompasses a pattern region extending on the surface of the mask. To accomplish the purpose of the pellicle which is to prevent particles from getting to the surface of the mask, the pellicle is disposed to isolate the pattern region from the external atmosphere so that particles in the external atmosphere are unable to reach the pattern region.
In recent years, the design rules for LSI have shifted toward more fineness to an order of sub-quarter micron, and this has urged shortening of the wavelengths of light sources with the result that mercury lamps for the g-line (436 nm) and i-line (365 nm) are being replaced by KrF excimer lasers (248 nm), ArF excimer lasers (193 nm) and the like. As required fineness is further increased, the flatness required of masks and silicon wafers is increased too.
The pellicle is attached to the mask for the purpose of fending particles off the pattern region only after the preparation of the mask is completed. It happens occasionally that when the pellicle is attached to the mask, the flatness of the mask is changed. If the mask flatness is lowered, problems such as de-focusing may take place. Also, when the mask flatness is lowered, the pattern configuration laid on the mask deviates from the original configuration, and a correct alignment is not obtained when masks are put assembled.
There are a number of causes that lead to change in the flatness of the mask, and it has been found that the most influential one is the comparatively poor flatness of the pellicle frame.
In recent years, the requirement for higher flatness of the mask has been strengthened from a flatness of 2 micrometers in the pattern region face, and since the time 65 nm node was introduced, a flatness of 0.5 micrometer or lower, or preferably 0.25 micrometer is required of the pattern face.
The Problems the Invention Seeks to Solve
In general the flatness of pellicle frame is only in the level of 20-80 micrometers, and when the pellicle having such flatness level, which is incomparable to that of mask, is attached to the mask, the pellicle's poverty in flatness is transferred to the mask whereby the mask is deformed. The pellicle is pressed to the mask under a high pressure of about 200-400 N (20-40 kg). The surface of mask is far flatter than the pellicle frame. Thus, after the forced attachment onto the mask, the pellicle frame starts straining itself to return to its original form, whereby the mask is caused to deform.
When the mask is deformed the flatness of the mask is often ill-affected, and this in turn causes the problems such as defocusing in the lithography equipment. On the other hand there are cases wherein the flatness of the mask is improved as the mask is deformed, but in such cases the pattern made in the mask surface is distorted, and as a result when the light is irradiated the pattern transferred to the wafer can be distorted too. This distortion of the pattern on the wafer also occurs in the cases where the flatness of the masks is degraded, so that in any case wherein the mask is deformed as the pellicle is pressed on it, the pattern transferred to the wafer is invariably distorted.
In order to solve this problem, there have been developed pellicle frames having higher flatness. However, in the environments wherein the pellicle is attached to the mask as well as wherein the pellicle frame is manufactured, the pellicle is subjected to physical force and heat, and the flatness of the pellicle frame is vulnerable to such influences especially temperature change. Therefore, the pellicle frame need be prepared against such influences.
SUMMARY OF THE INVENTION
To solve such problems described above, the present invention firstly proposes a method of manufacturing a pellicle whereby the deformation of the masks caused by the pellicle frame as the pellicle frame is attached to the mask is minimized. Secondly, the present invention provides a pellicle manufactured by such a method.
Means to Solve the Problems
The present inventors worked to find ways to solve the problems and came to possess the invention according to which:
(1) in making a pellicle having a frame with a first frame face to which a pellicle membrane is tensely pasted and a second frame face on which a pressure sensitive adhesive layer is laid, the frame is prepared by being subjected to a heat treatment at a predetermined temperature while being constricted between a pair of flat surfaces set against said first and second frame faces;
in an embodiment, the pellicle frame is laid on a flat surface with the second frame face in contact with the flat surface and the first frame face topped with a cover plate, and the frame is subjected to the preparatory heat treatment at the predetermined temperature, whereby the pellicle can substantially avoid undergoing frame deformation during later environmental temperature changes; and more preferably
(2) the pellicle frame is subjected to a preliminary heat treatment at a predetermined temperature while being constricted between a pair of flat surfaces pressed on the frame faces by means of a load, whereby the pellicle can substantially avoid undergoing frame deformation during later environmental temperature changes.
The inventors found that some of the resulting pellicle frames retained flatness of 3 micrometers or higher after the later thermal influences.
The inventors also found that the temperature for the preliminary heat treatment is preferably 140-250° C.
The inventors found that preferably the material for the pellicle frame is one that has a Young's modulus of 1-80 GPa.
Moreover, the inventors found a preferred material for the pellicle frame is an aluminum alloy.
Thus the present invention also provides a pellicle with a frame and a membrane pasted on one frame face of the frame and a pressure-sensitive adhesive layer laid on the other frame face for chucking the pellicle on a mask wherein the frame is pre-heated so that the pellicle does not undergo deformation during later hot environment.
According to the invention, it is possible to effectively obtain a pellicle frame having a flatness of 15 micrometers or smaller, and thus it is possible to minimize the deformation of the masks caused by the pellicle frame as the pellicle frame is attached to the mask.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a conceptual sectional view of an example of a pellicle plus mask.
FIG. 2 is a conceptual sectional view illustrating an example of a step of the present invention which is conducted while the pellicle frame is subjected to the heat treatment.
FIG. 3 is a conceptual sectional view illustrating an example of a step of the present invention which is conducted while the pellicle frame is constricted between a pair of flat surfaces and the pellicle frame is subjected to the heat treatment.
DETAILED DESCRIPTION OF THE INVENTION
Now, the present invention will be explained with reference to drawings.
As shown in FIG. 1 , a pellicle 6 for lithography according to the invention comprises a pellicle membrane 1 and a frame 3 . The pellicle membrane 1 is pasted on one of two frame faces of the frame 3 via an adhesive 2 laid on said one of the frame faces. On the other frame face is laid a pressure-sensitive adhesive layer 4 for attaching the frame 3 to a mask 5 , and over the pressure-sensitive adhesive layer is laid a separation layer or releaser (not shown), which is released prior to the attachment of the frame 3 on the mask 5 . A pellicle frame may be formed with a penetrating hole (no shown) to communicate the closed space defined by the pellicle and the mask to the atmosphere to thereby adjust the pressure inside said space. In addition, a filter for dust trapping may be provided inside the hole.
The pellicle frame may be formed with a jig hole. The configuration of the jig hole is not limited and may have a tapered recess at the end of the cylindrical hollow, so long as the jig hole extends horizontally to the frame faces and does not penetrate the frame bar. It is preferable that the cross section of the jig hole as cut by plane perpendicular to the hole axis is expanded at the external hole exit so that the hole has a recess to receive a filter for trapping the dust at its external exit.
The pellicle frame of the present invention shall be designed in accordance with the mask configuration, and in general the pellicle frame has a shape of circle, rectangle or square, and has such a width and configuration to entirely cover the circuit pattern area provided on the surface of the mask. The corners of a rectangular frame and square frame may be rounded.
The height of the pellicle frame, that is the distance between the upper frame face and the lower frame face, is preferably about 1-10 mm, and more preferably about 2-7 mm. The widths of the upper and lower frame faces, that is the distance between the inner wall and the outer wall of the pellicle frame not at the corners, is preferably 1-5 mm, and more preferably 2 mm.
As a material to make the pellicle frame, one having a Young's modulus of 1-80 GPa, such as aluminum alloy, magnesium alloy, and synthetic resin, is preferred, of which aluminum alloy is more preferred.
As for the choice from aluminum alloys, ones conventionally used to make pellicle frame are possible, and ones more preferred include JIS A7075, JIS A6061, JIS A5052 and the like, but so long as it is possible to form a frame with a cross section described above and with a strength required for a pellicle frame, there is no other qualification.
It is preferable to roughen the surface of the pellicle frame with sand blast or chemical washing prior to attachment of the membrane. In the present invention, it is acceptable to adopt any conventionally known method for roughening the frame surface.
A preferred choice, in the case of aluminum alloy frame, to roughen the frame surface is to blast the frame surface with grains of stainless steel or carborundum, or glass beads, and then wash the surface with a chemical such as NaOH.
It is also preferable to choose a material having a Young's modulus of 1-50 GPa to make a pellicle frame of the present invention in place of conventionally chosen aluminum alloys such as JIS A7075, JIS A6061, and JIS A5052, which have a Young's modulus of 69 GPa or so. Examples of materials having a Young's modulus in the range of 1 to 50 GPa include magnesium alloy (44 GPa), acrylic resin (3 GPa) and polycarbonate resin (2.5 GPa).
In the present invention, it is preferable that the endless frame bar is chamfered such that its cross section, taken as in FIG. 1 , becomes a rounded rectangle along the entire length of the frame bar. It is possible to chamfer only along the lower frame face or only along the upper frame face.
The flatness of an average pellicle frame is about 20-80 micrometers. In the present invention it is preferable that the pellicle frame has a flatness of 20 micrometers or higher, that is, less than 80 micrometers.
The higher the flatness of the pellicle frame, the smaller the deformation of the pellicle frame as the pellicle is attached to the mask. This results in lower flow stress in the pellicle frame, and decreased mask deformation.
The flatness of pellicle frame is defined as follows. The heights of eight points, four at the four corners and four at the middle parts of the four straight portions of the frame bar, are measured; from the result an imaginary plane is created by calculation, and of the distances of the eight points from the imaginary plane, the smallest value is subtracted from the largest value, and the result is the flatness.
In obtaining the flatness of the pellicle frame, a laser displacement sensor having an X-Y axis program stage can be used, and the inventors had one originally made inside the company and used it. In practicing the present invention, it is preferable that the pellicle frame is coated with a black oxide film and/or black polymer film since the pellicle frame absorbs stray light. Also, in the case where the pellicle frame is made of an aluminum alloy, it is especially proper to coat the pellicle frame with a black almite (alumite) film and/or polymer film by electro deposition.
A method, used generally, for creating a black almite film on the pellicle frame surface comprises first treating the pellicle frame in a bath of an alkali such as NaOH for several tens of seconds, conducting anodic oxidation in a dilute sulfuric acid, coloring in black, and finally sealing the frame surface, whereby the frame surface changes to a black almite.
The polymer film (polymer coating) can be created in various ways such as spray coating, electrostatic coating, and electro deposition, among which electro deposition is most preferable for polymer film creating.
The electro deposition is applicable to both thermosetting resin and ultraviolet curable resin. Also anionic electro deposition and cationic electro deposition are applicable to both of the resins. Since in the present invention an ultraviolet resistibility is required so that anionically electro-deposited thermosetting resin is preferable in the viewpoints of stability, appearance and strength of the coating.
The pellicle for lithography of the present invention can be completed, using any one of the pellicle frames described above, by tensely pasting a pellicle membrane on the upper frame face via an adhesive for pellicle membrane and laying an adhesive for mask on the lower frame face topped with a releaser.
The material of which the pellicle film or membrane is made can be anything conventionally used; for example, an amorphous fluorine-containing polymer which is used for excimer laser may be adopted. Examples of amorphous fluorine-containing polymer include Cutup (a product of Asahi Glass Co., Ltd.), TEFLON (a trademark), and AF (a product of Du Pont). To make a film from such polymers, one of the polymers may be dissolved in a solvent such as fluoro-philic solvent.
Next, a method of making the pellicle frame according to the present invention will be explained with reference to FIG. 2 . As shown in FIG. 2 , a pellicle frame 3 is placed on a base plate 7 , such as a quartz glass plate, with the lower frame face, on which a pressure-sensitive adhesive layer is later laid for chucking the frame on a mask, touching the base plate 7 , and a cover plate 8 , such as a quartz glass plate, is placed on the upper frame face of the pellicle frame 3 on which an adhesive layer for pasting the pellicle membrane is later laid. Then a heat treatment according to the invention is conducted.
The base plate 7 has flat upper and lower faces, and should have a flatness of 5 micrometers or higher.
The cover plate 8 is used to cover the upper frame face during the heat treatment. The cover plate 8 also is required to have flat upper and lower faces. An example is a quartz glass plate having a mass of 0.3 kg and a thickness of 6 mm.
In a preferred embodiment, a weight body is laid on the cover plate 8 , so that the cover plate 8 must have a reasonably high flatness to enable the weight of the weight body to evenly distribute on the top frame face of the pellicle frame 3 . The load upon the pellicle frame can exceed about 196 N (20 kg), but beyond 196 N the improvement in the resulting frame flatness is not justifiable. Without the load, and hence only the weight of the cover plate 8 is imposed on the pellicle frame, it takes a longer time to attain a result in the flatness of the pellicle frame 3 . Thus, a load of about 4.90 to about 196 N (0.5-20 kg) is preferable.
For the weight body, a lead plate, a standard weight, a compact weighty article, etc. will do.
The heat treatment at a predetermined temperature can be applied to the pellicle frame through an electro-conductive heater wound round the pellicle frame bar, or through radiation of an infrared rays to the frame, for example. It is also possible to heat-treat the pellicle frame by increasing the temperature of a system to a predetermined temperature in which the pellicle frame is kept.
It is preferable that the predetermined temperature for the heat treatment is 140-250° C. If the temperature at which the pellicle frame is heat-treated is lower than 140° C., the expected effect of reducing the thermal deformation is not obtainable. If the temperature is higher than 250° C., the frame surface tends to crack and discolor.
EXAMPLES
Now, examples of embodying the present invention will be explained, but the concept of the invention shall not be limited to the examples.
Pellicles frames with an outer dimension of 149 mm×122 mm, the frame bar being 3.5 mm high and 2 mm wide, were made out of an aluminum alloy, and they had a flatness of about 15 micrometers. The four corners of each pellicle frame were rounded by chamfering.
Example 1
On one face of a quartz glass plate 7 having a flatness of 5 micrometers or less was placed an above-described pellicle frame 3 with the lower frame face thereof being in contact with the plate 7 , and the upper frame face of the pellicle frame was topped by a quartz glass plate 8 ( FIG. 2 ). This assembly was heated for two hours in an oven at a temperature of 250° C., and the flatness of the lower frame face of the frame 3 was measured. Thereafter, the pellicle frame 3 was hung from a glass hook inside an oven, and was heat-treated at 250° C. for 20 minutes; then the flatness was measured again.
Example 2
On one face of a quartz glass plate 7 having a flatness of 5 micrometers or less was placed another one of above-described pellicle frame with the lower frame face thereof being in contact with the plate 7 , and the upper frame face of the pellicle frame was topped by a quartz glass plate. This assembly was heated for two hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 3 was measured. Thereafter, the pellicle frame 3 was hung from a glass hook inside an oven, and was heat-treated at 250° C. for 20 minutes; then the flatness was measured again.
Example 3
On one face of a quartz glass plate 7 having a flatness of 5 micrometers or less was placed another of above-described pellicle frame with the lower frame face thereof being in contact with the plate 7 , and the upper frame face of the pellicle frame was topped by a quartz glass plate. This assembly was heated for two hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 3 was measured. Thereafter, the pellicle frame 3 was hung from a glass hook inside an oven, and was heat-treated at 185° C. for 20 minutes; then the flatness was measured again.
Example 4
On one face of a quartz glass plate 7 having a flatness of 5 micrometers or less was placed still another of above-described pellicle frame with the lower frame face thereof being in contact with the plate 7 , and the upper frame face of the pellicle frame was topped by a quartz glass plate. This assembly was heated for two hours in an oven at a temperature of 140° C., and the flatness of the lower frame face of the frame 3 was measured. Thereafter, the pellicle frame was hung from a glass hook inside an oven, and was heat-treated at 185° C. for 20 minutes; then the flatness was measured again.
Example 5
On one face of a quartz glass plate 7 having a flatness of 5 micrometers or less was placed yet another of above-described pellicle frame with the lower frame face thereof being in contact with the plate 7 , and the upper frame face of the pellicle frame was topped by a quartz glass plate. This assembly was heated for two hours in an oven at a temperature of 140° C., and the flatness of the lower frame face of the frame 3 was measured. Thereafter, the pellicle frame 3 was hung from a glass hook inside an oven, and was heat-treated at 140° C. for 20 minutes; then the flatness was measured again.
Comparative Example 1
An above-described pellicle frame was hung from a glass hook inside an oven, and was heat-treated at 250° C. for 20 minutes; then the flatness of one of the frame faces was measured.
Comparative Example 2
An above-described pellicle frame was hung from a glass hook inside an oven, and was heat-treated at 185° C. for 20 minutes; then the flatness of one of the frame faces was measured.
Comparative Example 3
An above-described pellicle frame 3 was hung from a glass hook inside an oven, and was heat-treated at 140° C. for 20 minutes; then the flatness of one of the frame faces was measured.
The results of flatness measurements are entered in Table 1 below.
TABLE 1
2nd heat
flatness (micrometer)
1st heat
treatment
before 2nd
after 2nd
treatment
temperture
heat
heat
temperature
(° C.)
treatment
treatment
Example 1
250
250
14
16
Example 2
185
250
15
16
Example 3
185
185
15
15
Example 4
140
185
17
20
Example 5
140
140
15
17
Comparative
none
250
16
79
Example 1
Comparative
none
185
15
48
Example 2
Comparative
none
140
16
31
Example 3
Pellicles frames 10 with an outer dimension of 149 mm×122 mm, the frame bar being 3.5 mm high and 2 mm wide, were made out of an aluminum alloy. The four corners of each pellicle frame were rounded by chamfering.
Example 6
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 12 ( FIG. 3 ). A weight 9 of 2 kg was laid on the quartz glass plate 12 . This assembly was heated for two hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 7
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 12 . A weight of 2 kg was laid on the quartz glass plate 12 . This assembly was heated for two hours in an oven at a temperature of 140° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 8
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 12 . A weight of 2 kg was laid on the quartz glass plate 12 . This assembly was heated for two hours in an oven at a temperature of 250° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 9
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 12 . A weight of 2 kg was laid on the quartz glass plate 12 . This assembly was heated for 20 minutes in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 10
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 12 . A weight of 2 kg was laid on the quartz glass plate 12 . This assembly was heated for 15 hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 11
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass cover plate 12 . A weight of 0.5 kg was laid on the cover plate 12 . This assembly was heated for 15 hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
Example 12
On one face of a quartz glass plate 11 having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the base plate 11 , and the upper frame face of the pellicle frame 10 was topped by a quartz glass plate 11 . A weight of 20 kg was laid on the cover plate. This assembly was heated for two hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
Comparative Example 4
On one face of a quartz glass base plate having a flatness of 3 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the base plate, and the upper frame face of the pellicle frame 10 was topped by a quartz glass cover plate. A weight of 2 kg was laid on the cover plate. This assembly was stored for 2 hours in an oven at the room temperature, and the flatness of the lower frame face of the frame 10 was measured.
Comparative Example 5
On one face of a quartz glass base plate 11 having a flatness of 15 micrometers was placed an above-described pellicle frame 10 with the lower frame face thereof being in contact with the base plate, and the upper frame face of the pellicle frame 10 was topped by a quartz glass cover plate 12 . A weight of 2 kg was laid on the cover plate. This assembly was heated for 2 hours in an oven at a temperature of 185° C., and the flatness of the lower frame face of the frame 10 was measured.
The results of flatness measurements are as shown in Table 2 below.
TABLE 2
Heat treatment conditions and the measurement results of
Examples and Comparative Examples
heat treatment conditions
quartz glass
tem-
flatness measured
plate
pera-
before 2nd
after 2nd
flatness
ture
load
time
heat
heat
(micrometer
(° C.)
(kg)
(hr)
treatment
treatment
Example 1
3
185
2
2
24
12
Example 2
3
140
2
2
21
15
Example 3
3
250
2
2
24
11
Example 4
3
185
2
0.2
19
15
Example 5
3
185
2
15
18
9
Example 6
3
185
0.5
15
20
15
Example 7
3
185
20
2
23
10
Comparative
3
20
2
2
24
24
Example 1
Comparative
15
185
2
2
23
22
Example 2 | There is provided a method for manufacturing a pellicle in which the pellicle frame is prepared by being heated at a predetermined temperature while constricting the frame to some extent of flatness to achieve a desired flatness and future stability against heat. | 6 |
RELATED APPLICATIONS
This patent arises from provisional patent application No. 60/732,831 filed on Nov. 2, 2005, entitled “PRINTER DRIVER SYSTEMS AND METHODS FOR AUTOMATIC GENERATION OF EMBROIDERY DESIGNS”, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
The present disclosure pertains to automatic generation of embroidery designs and, more particularly, to printer driver systems and methods for automatic generation of embroidery designs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 : Example printer driver system for generating embroidery designs when printing documents via a general purpose computer operating system
FIG. 2 : Example operations of the example printer driver system of FIG. 1 .
FIG. 3 : Example operations of an example compositing method used by the printer driver system of FIG. 1 .
FIG. 4 : Example of Compositing Input Records for a Printing File Containing Three Overlapping Polygons. FIG. 4 shows an original printing file containing three overlapping polygons [two red, one blue (with a hole)]. The output contours (here 5 polygons) are shown on the right.
FIG. 5 : An example illustration of handing collinear cases: Lines [AB], [CD] and [EF] are collinear segments. Points C, E, F, D are reported as intersection points. As a result, four intersection points are inserted into line [AB], two points are inserted into line [CD]. Note: collinear segments are handled in lines 4 and 15 without increasing the degree of the algorithm.
FIG. 6 : Segment Pairs using winding rule fill mode illustrated. A is the starting drawing point. Segment pairs are {ABleft, CDright} and {EFleft, PQright} at event point A in (a). Segment pair is {ABleft, PQright} at event point D in (b).
FIG. 7 : Segment Selection and Duplication
FIG. 8 : Re-order of Coincident Segments Hit by Scan Ray (i.e. segments have identical end points).
FIG. 9 : Part (a) shows coincident segments in a Segment Pool and the incorrect hole that may potentially be generated. Part (b) shows the correct result with no coincident/redundant segments.
FIG. 10 : V 1 is the first event point in this example. After traversal at V 1 , edges in dashed lines are visited edges. At event point P 1 , Edge P 1 P 2 is the start traversal edge. P 1 P 6 is to the left of edge P 1 P 2 and is unvisited. Therefore, traversal edge P 1 P 2 generates a hole. Similarly, at event point M 1 , edge M 1 M 2 is an odd edge and on the left edge V 1 V 7 has been visited, therefore, traversal edge M 1 M 2 generates the outer edge of a new polygonal object.
FIG. 11 : The left side shows an outline traversal in segment pool A. At vertex D, there are three edges that can be chosen: edge DE, DF and edge DG. Since the traversal started at event point A indicates an outer edge and DE is the leftmost of the three edges (DE, DG and DG) it is chosen. A hole traversal in a segment pool B is shown on the right. At vertex D′, there are three edges that can be chosen: D′E′, D′F′ and D′C′. Because the traversal path starting at A′ indicates a hole, the rightmost edge D′C′ is chosen.
FIG. 12 : Example graphics metafile. Left: original metafile image, Middle: wire-frame outlines of original metafile records, Right: wire-frame outlines of composite result.
FIG. 13 : Illustration of example end-cap types and join types.
FIG. 14 : Illustration of an example method to generate round end-cap stroke path outlines.
FIG. 15 : Illustration of an example method and generate square end-cap stroke path outlines.
FIGS. 16 and 17 : Example method to process round type joints.
FIGS. 18 and 19 : Example method to process miter type joints.
FIGS. 20 and 21 : Example method to process bevel type joints.
FIG. 22 : Represents the process or machine readable and executable instructions to find segment pairs when a winding-rule fill mode is specified.
FIG. 23 : Represents the process or machine readable and executable instructions delineating the general elimination, selection and duplication process.
FIG. 24 : Modified segment arrangement criteria for the situation of multiple coincident segments.
FIG. 25 : Polygonal Intersection Processes.
FIG. 26 : Sorted Segments inside Status Tree. There are three segments in this figure; they are: [AB], [EF] and [CD]. At event point E, the order of the segments in the status tree is: [EF], [CD], [AB], in sequence.
FIG. 27 : Example of Twin Segment
FIG. 28 : Example of border information. In this situation, edge border information for object 50 is: edge V1V2 border ID is 10, V2V3 border ID is 30, and V3V1 border ID is 20.
DESCRIPTION
Printer drivers are traditionally software programs that facilitate communication between an operating system's printing sub-system and an actual hardware device that physically imprints a particular type of substrate. While considerable complexity may exist in the implementation of a printer driver, from the end user's perspective, utilization of such a driver appears simply as part of a seamless process whereby the user selects a “print” command under a given application running within the operating system and then the active document within that application is visually reproduced on the desired printing device. Under some circumstances, printer drivers are used to produce output that is not directly communicated to an actual hardware device. In such cases, the printing device may be referred to as a “virtual” printer in that it may exist to primarily produce electronic files (e.g. image or typesetting files such as jpeg's, bmp's or pdf's). Once created, these files may then be subsequently viewed, transferred or edited by the user for a variety of purposes.
The method described here specifies a printer driver that can be thought of in either sense (i.e. traditional or virtual) and is unique in that it produces output that effectively reproduces printed documents as embroidered designs. This output when connected to actual hardware such as an embroidery machine allows the machine to appear to the computer operator as simply another printer to which documents may be easily sent. When not connected to hardware, the driver provides the functionality of a virtual printer whereby an embroidery data file may be generated that effectively encompasses the complete specification of an embroidery design. This data file may then be used to view a pictorial representation of embroidery data on a computer screen for editing or further manipulation. Alternatively, this data file may also be manually transferred as input to embroidery equipment where the file presents all data necessary for the equipment to sew out or produce the related embroidery design on material or a provided garment. In another embodiment, this data file can be transferred to a web-service to be embroidered on apparel like T-shirts or hats. The actual transfer may be done using many different protocols like html, low-level sockets, web-service protocols like SOAP, XML-RPC, etc. The printer driver may transfer the low level vector graphics information to the web-service, which then generates embroidery data based on that information. The user is then directed to the web-page through a browser, where he can manipulate the design and select garments on which he wants the design embroidered. After the user confirms the selection the, embroidered garments are delivered to him.
The embroidery process is substantially different from other more traditional imprinting technologies such as CMYK inkjet processes or screen printing processes. Images are created on fabric using embroidery by placing sequences of stitches at various locations, with various orientations, using a multitude of thread colors. One common type of information stored within embroidery data relates to the relative locations of needle penetration points. This information is often stored using a Cartesian coordinate system (e.g. sequences of x, y values representing the horizontal and vertical location of each needle penetration and subsequently the end point locations for stitches which may be visualized as small line segments). There is already at least one automated system known and disclosed within U.S. Pat. Nos. 6,397,120, 6,804,573, 6,836,695 and 6,947,808 that allows automatic conversion from graphical data (e.g. a scanned image bitmap) into embroidery design data. These patents disclose various aspects of image preparation, shape interpretation, and translation to specific embroidery data primitives based on a variety of factors. The methods described here can be used to preprocess and integrate the raw data supplied by an operating system to its printing subsystem such that it may be re-formed in a way that makes it appropriate or compatible as input to an automatic embroidery data generation system. More specifically, an overview of the systems methods disclosed here is presented in FIG. 1 and employs a low-level printer driver that forwards various types of printing commands to a variety of supporting software. Overall, allowing the user to convert artwork into embroidery designs by the simple act of printing that artwork (e.g., clicking a print button) may offer considerable advantage over other potential methods such as saving the artwork in specific formats or at specific resolutions for later importing by an automatic embroidery generation system. This contrast in use is one of several features that distinguish it from other methods.
The printer driver that facilitates the disclosed method may be configured as a raster printer that supports bezier curves and other forms of vector and bitmap data (e.g., vector outline representations of fonts, rectangles, ellipses, etc.). Configuration in this way, for example, tells the printer subsystem to send font glyphs instead of bitmaps and bezier curve points instead of normal straight line paths for outline data. This is useful in that it may provide greater accuracy in the image specification when compared to simple, fixed resolution bitmap information. Vector data is the term used to refer to graphical information where a region is specified by mathematically precise shape specifiers such as the edge contours that bound it. Often these boundaries are described as smooth curve or poly-line information. Alternatively, bitmap or raster data refers to more discrete data often in the form of pixels, where a region is specified as a function of what groups of pixels it contains. When the print driver is forced to process bitmap data (e.g., as a result of such data being forwarded from an application program), processing such as that described in previously mentioned prior art should be performed to convert that data to vector outline information. Once vector data is obtained, it is then the responsibility of the printer driver to further process it in order to make it suitable for embroidery design generation.
When a user prints a particular document (using the print facility supported by the computer's operating system), the printer subsystem calls various routines in a printer driver DLL (dynamic link library) with data to be printed. Example names of such routines may include DrvTextOut, DrvBitBlt, DrvFillPath, and DrvStrokeAndFillPath. These are some of the routines that are standardized as part of the Microsoft Windows operating system printing subsystem. The implementations of these driver routines, as developed in the preferred embodiment described here, convert this vector information into more basic data structures that specify regions such as polygons, rectangles and paths, and then store them as records in a dynamically sized memory block. The path structure may be composed of several sub paths, which are typically either straight line paths or bezier curve points. A path structure may be composed of multiple closed figures formed from several sub paths. The printer dll may also generate additional parts of a path required to close a figure by connecting the first and the last points in a path or sub-path structure.
The closed or open figures (i.e., shapes) resultant from path structures may be of two types—fill and stroke. A fill shape uses a path structure to delineate its outer most boundaries, whereas a stroke shape uses a path structure to delineate a continuous curve with a predetermined thickness and is typically not actually bounded by the path or sub-path. The printer subsystem specifies a number of attributes to be used to draw such shapes. For example, for fill shapes, the printer subsystem could specify the brush type and color while for stroke shapes it could specify pen color, pen width, end cap and join types. More examples on the type and variety of properties that may be specified for shapes at the printer driver level may be found within printer driver development documentation provided by Microsoft and other operating system vendors. This information is associated with the record of each individual shape. Some of the properties specified by the printer subsystem might not be able to be expressed directly as stitches because of the inherent limitations of embroidery. In such situations, the closest representation may be automatically chosen by default while the user may choose to modify it later-in or completely-after the embroidery generation process. For example, a pattern brush specified for a fill shape would be presented as a solid brush to the system with a default color where this shape will translate to a particular area of embroidery using the specified color as a thread color using a specified fill pattern to approximate the texture or nature of the pattern.
After the printer subsystem signals an end to the printing of a document (e.g., by calling the function DrvEndDoc) the printer dll transfers raw vector data to the Embroidery Generation Support Program (referred to hereafter as the EG method). Various methods can be used to transfer the data to the EG method such as saving it to a (temporary) file, passing individual messages for each record or utilizing a shared block of memory. In one embodiment, the printer dll passes a predetermined unique message to the EG method indicating that the raw vector data is available in a shared memory block. Prior to passing the message, the printer dll copies the shape records and associated information in a predetermined order from the internal dynamic memory block to the shared memory block.
The EG method uses a Path Generator (PG) method to generate polygonal boundaries from generic curves/poly-lines and also for stroked paths (e.g., sequences of curves and line segments to be drawn using a GDI pen with particular attributes). Line attributes that are associated with pen types (e.g. pen width, pen color, etc.) may then be used to create a set of polygons that delineate an exterior edge boundary of a stroked path. In some cases, Microsoft Windows® GDI path functions may be called to generate polygons along a stroke path which are visually identical to the original line drawing path after filling occurs during rasterization. However, these functions are typically not sufficient for use here since their precision is often tied to a particular raster resolution.
The EG method then uses a Metafile Compositing (MC) method that sequentially takes shapes (e.g., polygons) where filling modes and color attributes are specified as input and then outputs a set of consistently formed non-overlapping maximally contiguous regions. Input polygons need not necessarily be regular polygons, i.e. polygon vertices may be specified in any order (clockwise or counter-clockwise) and the polygon itself may be self-overlapped. The output is order-specified, i.e. the outer most edge for each region is specified in a counter-clockwise order and any contours indicating holes are specified in a clockwise order. This constraint may not be required, but is often useful in simplifying many subsequent processing tasks including computation of intermediate data such as skeletons (e.g., Voronoi diagram computation), deformation of regions, etc. The EG method then analyzes the composite objects (i.e. the outputted regions) and generates stitch data which can then be fed to an embroidery machine for stitching. The actual methods used to generate stitch data are similar to those already disclosed in the previously mentioned prior art system. A more detailed description of the EG method and some related methods is now provided.
A stroked path typically has symmetrical properties. Specifically, all end-cap types are symmetrical along the path's center line; all types of joints are symmetrical along the joint angle bisectors. The PG method maintains visual features after adding the stroke outline points and maintains shared points between different connected segment paths consistently. Thus, paths generated by the PG method may be substantially more accurate and resolution independent than ones generated by built-in GDI functions.
The PG method invokes several methods to compute the end cap and joins based on the attributes specified at the print driver level.
The Process Round End Cap (PREC) method is used to compute edge boundary vertices at the end point of a stroked path when the selected pen type indicates round end caps as one of its attributes. To maintain the symmetrical property of the round end-caps, the middle point of the arc (Refer to FIG. 14 ) is added first, then boundary edge vertices on left and right sides of the arc are added recursively until a minimum threshold value for smoothness of the arc is meet. Detailed operations of the process are illustrated in FIG. 14 .
The PG method uses a Process Square End Cap (PSEC) method to compute edge boundary vertices at the end point of a stroked path when the associated pen type indicates squared end caps. Right corner points and left corner points are added first. Example operations are shown in FIG. 15 .
Process Round Join (PRJ) method is used to compute edge boundary vertices when the selected pen type indicates a round join type. First, the bisector of the two connected path segments is computed (see FIG. 16 ). For the convex side of the path, two vectors are projected from the common join point of the specified related medial path where each vector is projected a distance of one half the pen width and orthogonal to each of the related medial path line segments. The ends of these vectors indicate the end points of the curved boundary to be computed on the outer convex edge side of the path. Then the endpoint of a bisector of these two vectors (again projected a distance of one half the specified pen width) is inserted into the boundaries vertex list. The rest of the vertices are then computed by recursively introducing new bisectors as specified in FIG. 17 and illustrated in FIG. 16 .
Process Miter Join (PMJ) method is used to compute edge boundary vertices when the selected pen type indicates a miter join type. Here the bisector of the two connected path segments is computed (see FIG. 18 ). Point P y on the concave side (see FIG. 18 ) is computed on the bisector based on the path radiation R (i.e., based on one half the specified pen width). Point P x on the convex side is computed based on the miter limit length. If the limit is not set with the associated pen property, then P x is computed using the extensions of two side boundaries (see FIG. 18 ).
Process Bevel Join (PBJ) method is used to compute edge boundary vertices when the selected pen type indicates a bevel join type. The bisector of the two connected path segments is computed (see FIG. 20 ). Point P y is computed similar to the methods used within the PMJ method. Point P x is calculated on the bisector based on the pen width. Line P m P n is calculated perpendicular to the bisector line and Point P m and P n are the intersections with two side boundaries which are parallel to the related path segment. A final boundary shape is illustrated in FIG. 20 . The MC method (also referred to as the compositing method) receives the printing records and translates them into a set of closed contours that delineate the contiguous regions equivalent to those that would result from rendering (e.g., printing) the original file on an arbitrarily sized display. These printing records may be thought of as analogous to a computer graphics metafile (CGM) specification in that they are an ordered list of commands that may be used to reproduce a visual picture or image. The ISO specification is a four-part standard defining a file format for the application-independent capture, storage and transfer of graphical pictures. Compositing computer graphics metafiles (CGM) is the process of applying various Boolean operators among potentially overlapped primitive shapes specified within a file designed to create a visual image. On a raster-type device such as a computer's CRT display or inkjet printer when a subset of vector commands overlaps or otherwise intersects with previously drawn or executed commands, the pixels within the overlapped areas are simply reset to the color specified by the more recent vector commands. Thus, potential redundancies within a metafile (i.e. situations where multiple commands repeatedly “paint” within the same area) are resolved through a process of rasterization in which more recent commands always take precedence over those that were previously executed. However, for many applications, the loss of flexibility that results from rasterization (e.g., loss of detailed outline information) makes it less suitable for developing a usable composite representation of a metafile's vector commands. Specifically, it may be desirable to eliminate redundancies within vector outlines by actually modifying the underlying outlines directly so that painting within any given area never occurs more than once (i.e., no overlapping occurs). This may provide such benefits as greater compression of picture information. Also, the result may be used for other applications such as computerized embroidery imprinting in which it is often undesirable to repeatedly sew or place stitches within a single area of fabric. Note that compositing is not a strict requirement of the print driver method disclosed here. Without compositing, embroidery data may still be generated separately for each of the individual underlying print records. However, there are many situations where such an approach yields embroidery data that may not be practical for actual production on embroidery equipment (e.g., sewing repeatedly over the same area or triggering excessive thread trims or redundant needle movements even when sewing a single same-colored contiguous area). Hence, compositing is included here as a desirable step to achieve a more consistent usable result for embroidery data generation.
The compositing method is comprised of four general operations: 1) Finding intersections among the edges of regions (e.g., polygonal boundary intersection). 2) Finding segment fill pairs. 3) Arranging segments and 4) Re-establishing segment lists and the resultant associated output regions.
The MC method first executes a Find Polygonal Object Boundary Intersection (FPOBI) method which permits the reliable and predictable detection of intersecting polygonal edges. This method makes use of the line sweep technique and algebraic predicates, but has also been further extended to handle additional requirements and degeneracies precipitated by the compositing operations. Some of the degeneracies have been tackled individually in previous work, but still do not facilitate a comprehensive and robust solution to the specific issues discussed here. Previous work includes a method for testing two simple polygonal objects using enveloping triangulations. Another method includes heuristics for detecting whether two polygons intersect using a grid-based method, a method that works optimally when the polygon edges are distributed in a uniform manner (which would not be typical of input cases dealt with here). This method offers some distinct benefits when compared to basic line-segment intersection algorithms. Numerous methods have been presented that solve the problem of finding intersections among line-segments. Unfortunately, it has also been shown that several prior art methods largely rely upon models of exact computation that may become computationally impractical for engineering solutions implemented using hardware which supports only IEEE floating point representations. One previous method proposed the plane-sweep algorithm for finding intersections among line-segments which solves the problem in time O((n+k)logn). This method also has been reported to be quite sensitive to numerical errors and, hence, must also rely upon a model of exact computation to produce correct results. Thus, one proposed solution relies upon algebraic predicates to alleviate many of the numerical issues prevalent in the line sweep algorithm and argue that this algorithm may be superior to others since it requires a comparatively lower degree predicate than that which would be required by other algorithms.
The MC method is different from Polygon Clipping or other operators that compute Boolean operations among specified regions. Algorithms that facilitate a Boolean set of operations that may be used to unite, subtract, or intersect solid objects with each other is a common component of many solid modeling systems. Polygon Boolean operations are derived from polygon clipping algorithms. Many polygon clipping algorithms have significant limitations, (e.g., some algorithms are limited to convex polygons, some algorithms require that the clip polygon be rectangular; some algorithms do not allow polygon self-intersections). Commonly encountered CGMs (computer graphics metafiles) cannot be easily modified to adhere to such restrictions (including those produced by the print driver method described here). Even the simple case of detecting if one polygon lies within the boundaries of another polygon becomes less obvious when one of the input polygons intersects with itself (a degeneracy that is common within metafile records). Vatti's algorithm and Greiner and Hormann's algorithm can be used for testing polygon self-overlaps by counting the winding number. However, overlaps that result in zero-area portions of the polygon would still not be eliminated as is inherently required by the problem presented here. Many efficient polygon clipping algorithms have been published in the literature, however, a direct substitution of such algorithms to handle the task of metafile compositing is generally infeasible. Hence, the metafile compositing method described here is largely focused on developing Boolean operators suitable for input sets with large numbers of polygonal objects containing varied degeneracies, to provide a fast, robust, comprehensive and practical solution.
The MC method is related to the problem of map overlay studied within computational geometry. Solutions to this problem involve detecting and subsequently processing the intersections and unions of polygonal objects that are placed within a two-dimensional space (e.g., outlines of highways, rivers, lakes, etc.). Thus, if each vector command within a graphics metafile is considered as a layer in a geometric map, the techniques used in map overlay may be applied to the problem of metafile compositing. The input of a map overlay operation consists of two or more topologically structured layers and the output is a new layer in which the new areas in that layer are given attributes that are based on the input layers. The procedures are similar in that an overlay operation takes two or more data layers as input and results in an output layer, just as a metafile contains many records and the output may be considered as a single layer. However, there are several differences. First, the ordering of input records or layers within metafile compositing is important; if the input order is changed, the output may be different. Thus, when applying map overlay algorithms to metafile compositing, the time sequential features of the metafile records are taken into account. Second, in map overlay algorithms, different layers have different attributes. However, in metafile compositing, different records may have identical attributes, for example, the same color. Therefore, in certain situations, merging operations may be performed for same attribute layers when constructing the output. Finally, in map overlay one region may receive attributes from many layers; in compositing CGM, any given region typically only receives attributes from a single record.
CGM command records (e.g., the printing records) may contain degenerate polygonal objects, such as zero-length segments, zero-area polygonal objects, grazing and self-overlapping. Many records may also be drawn in the same region redundantly. The vertex list order is not specified. The closed area is the brush painting area, thus, some records may be drawn in clockwise order while others are drawn in counter-clockwise order. CGM records may be attribute filled using different modes (e.g., alternate edge/scanline versus winding rule fills). Filling modes must be considered to generate correct results.
CGM input records paint arbitrary, potentially overlapping regions sequentially where the ordering of records combined with their fill attributes is important. For example, for records with different fill colors, the newly drawn record hides the previously drawn record if they are overlapping or partially overlapping. Based on this property, the Boolean operation of “NOT” is performed if two input records have different colors and the newly drawn record has a higher drawing priority (e.g., is present later within the list of input records).
Overlapping records that have identical fill attributes (e.g., same color) in certain instances may be processed to eliminate the extra overlapping portion since this does not affect the visual appearance of the metafile. Thus, in these instances, a merging or logical “OR” operation may be performed.
Other prior art methods such as graph exploration for overlaying planar subdivisions do not address issues of numerical accuracy or degeneracy within input data sets. Unfortunately, without consideration of such issues, a practical and robust solution is difficult to obtain. Examples of such degeneracies include zero-length segments, zero-area polygonal objects, grazing, self-overlapping, and multiple congruent polygonal region boundaries. The MC method disclosed here has been shown to work for very large numbers of polygons where such input data may contain large numbers of degeneracies of the types mentioned previously. The method considers not only the original geometric coordinates, but also the original drawing sequence and filling modes. Output display is visually identical to the input, the difference being that all overlap of dissimilar attributes and all adjacency of like attributes are removed. The method's performance within the presence of degeneracies and large input sets is one feature which distinguishes it from previously published related work.
In order to disclose the details of the MC method some basic definitions are first provided. The terms defined may relate to terminology used here as well as in prior art that may discuss other methods that employ sweep-line approaches to solve problems within computational geometry. First, an “event point” is defined as a point in the plane at which the sweep algorithm evaluates and processes current input and data structures. Event points are ordered according to their y and then x coordinate values. In the MC method event points are the endpoints of line segments or computed intersection points between two or more line segments where these line segments represent the outer boundaries of polygonal regions. An “edge” refers to the connection between two event points (i.e., its end points). Its domain is a finite, non-self-intersecting open curve. An edge has two end-points and its length is greater than zero. E[A i A j ] denotes an edge that has A i and A j as its end-points. A “segment” is similar to an edge in that it is also a closed line. It stores an upper-end-point and a lower-end-point. Let S[A i A j ] denote a segment that has A i and A j as its end-points. Let A i < y A j denote that point A i is smaller than A j along the y-axis. Similarly, A i < x A j denotes that point A i is smaller than A j along the x-axis. If A i < y A j , or A i = y A j and A i < x A j , in the printer device coordinate scheme, A i is the upper-end-point and A j is the lower-end-point. A “segment pair” consists of two segments which intersect the sweep line and lie on opposite edges of a given region. It indicates an area between two segments that is part of a GDI fill area for a particular metafile record or polygonal object. A “segment pool” contains segments having a particular attribute (e.g., color) as inherited from the original input data (i.e., the attribute of its related polygonal object). Multiple segment pools are maintained within the MC method where there is one and only one pool for every attribute present within the input data. A segment pool invariant is that while segments may share end points, no segment within a given pool may be coincident with any other segment within that pool. Note: segments may be added to a particular attributed pool, even though originally they may not have exhibited that attribute. However, once added to the pool they then lose their previous attribute and inherit that of the pool. A half opened edge, which only includes the origin point, is called a “half-edge.” E[V i V j ] denotes a Half-edge that has vertex V i as its origin and vertex V j as its destination. If one walks along a main-half-edge, the face of an associated region lies to the left. For a twin-half-edge, the face of an associated region lies to the right. A closed polygon P is described by the ordered set of its vertices V 0 , V 1 , V 2 , . . . , V n , V 0 =V n+1 , where n>=3. It contains all main and twin half-edges consecutively connecting the vertices V i , i.e. the main half-edges are E[V 0 V 1 ), E[V 1 V 2 ), . . . E[V n−1 V n ), E[V n V n+1 )=E[V n V 0 ) and the twin half-edges are E[V n V n−1 ), E[V n−1 V n−2 ), . . . E[V 1 V 0 ), E[V 0 V −1 )=E[V 0 V n ). A “polygonal object” O is described by a set of polygons P 0 , P 1 , P 2 , . . . , P n where P 0 is the outer polygon, which is specified in a counter-clockwise order and P 1 , P 2 , . . . , P n are inside P 0 and are specified in clockwise order. In terms of metafile compositing, a polygonal object is a distinct, named set of attributes that represents a contiguous graphic region. The attributes hold data describing the graphic, such as color, drawing sequence, etc.
Let S be the set of segments of all polygonal objects in the plane. Let Q be the sorted vertices of segments (sorted by y and then x values) in the plane; these points will be evaluated as “event points” within the algorithm. Let τ be the sorted list that stores those segments that intersect with a sweep line. P is the pointer that indicates the current event point being evaluated within Q. Let U(P) be the set of segments which have P as their upper endpoint. Let L(P) be the subset of τ which has P as its lower endpoint. Let C(P) be the subset of τ which has P as its interior point, meaning P is on that segment but is not the endpoint. S l (P) and S r (P) denote, respectively, the left and right neighbor segments of P in τ. Let A be the collection of segments in τ (the status tree). Let M l (A) be the left-most segment of A and M r (A) be the right most segment of A. Note, lines of pseudo-code shown in FIG. 25 represent an overview of the method used to find boundary intersections. Lines printed in bold, represent modifications over that which was presented in previous methods.
There are many differences between the sweep-line methods disclosed here when compared to other commonly-known sweep line algorithms. Other published algorithms do not address details on the treatment of special cases and degeneracies or, when present, such details are only partially explained. For example, some methods assume any two segments or curves will intersect at most at a single point which may not be true. Here, an attempt is made to avoid such assumptions and fully consider the details of degenaricies to allow a comprehensive engineering solution.
A predicate arithmetic model is used to determine if two segments intersect in line 1 of FindNewEvent (see FIG. 25 ), an approximation of this intersection point is also computed and stored. Using algebraic predicates, the determination of whether two segments intersect is guaranteed to be correct as long as input data coordinates do not exceed what may be represented by 24-bit integers. In this specific application, input coordinates of metafile records are stored as 16-bit integers. However, the construction and storage of actual resultant intersection points does not have the same guarantee of accuracy and inevitably some rounding of results may occur potentially shifting the locations of intersection points from their true positions. Such rounding may potentially impact the final output in that certain polygonal vertices may be inaccurate to the extent that IEEE floating point arithmetic results yield slightly different values for their positions. However, particular care is taken such that this rounding will not prevent the method from constructing its output. This is primarily achieved by assuring some degree of consistency in the rounding that will occur and allowing the algorithm to effectively ignore such rounding. For example, when two segments intersect, where one or both of those segments emanate from previously computed intersections at one or more of their end points, the original end points of the related segment (rather than the “intersection end points”) are used for both detection and construction of an intersection point.
It has been suggested that the order of the segments in the status-tree corresponds to the order in which they are intersected by the sweep line just below the related event point. However, this appears to be insufficient in some cases (see example in FIG. 26 ). According this method, the key value for [AB] cannot be found, because an intersection point below the sweep line is not present. Here, in such cases, a super-key may be used to sort the segments in the status-tree: the first attribute of the super-key is the x-coordinate of the point intersected by the sweep line and the segment at the event point; the second attribute of the super-key is the segment's slope.
An intersection is a point where lines intersect by definition. This definition is used by most previously published work. However, for polygonal object intersection, this is not always applicable. If two segments from the same polygonal object intersect at both end points, this intersection may not be considered as an intersection of the object. Only intersections of segments that are from different polygonal objects should be reported. In lines 6 , 17 , 19 and 22 of HandleEventPoint and line 5 of FindNewEvent, segment classification is performed before reporting intersections. Typical CGM records cannot be assumed to be simple polygons. Rather, they tend to exhibit all types of deficiencies, such as self-intersections and grazing contact between multiple polygons (e.g. holes) even within a single polygonal object. The above algorithm can be modified slightly for detecting and finding self-overlapping intersections.
These compositing methods presented here are intended to eliminate redundant segments and re-establish link-listed polygonal objects. This is accomplished primarily through the creation and use of segment pools where segments having a particular shared attribute are organized together in a single pool. As the sweep-line process progresses, each segment (through its association with a segment pair) may either be discarded or moved to one or two segment pools. Another invariant of the sweep-line process regarding segment pools is that while segments may share end points, no segment within a given pool may be coincident with any other segment within that pool and no two segments will cross each other. Preservation of this invariant is largely addressed within the Overlapped Segments Selection Criteria algorithm summarized in FIG. 24 . For example, lines 2 and 3 of the algorithm imply that S m or S n may be selected into different segment pools with different attributes or neither may be selected. Similarly, the duplication rule cannot generate coincident or duplicated segments to an individual segment pool. After this sweep completes, a segment pool has the property that traversing segments within the pool (via another sweep pattern) generates one or more cycles (i.e., closed contours containing no self-crossings).
Segment pairs (see definitions disclosed earlier in this specification) are found at each event-point (event-points include original segment end points and segment intersections) based on CGM filling rules. These pairs are intended to indicate areas between each pair that comprise filled portions of related polygonal objects. Finding segment pairs is a pre-processing step for segment arrangement (e.g. selection and duplication to segment pools) that effectively eliminates unneeded or redundant segments of a polygon (i.e. segments that have been occluded due to filling rules or self overlap). Similar to the algorithm used for finding intersections, it is assumed that a scan-line goes from top to bottom, halting at each event point. Segment pairs are easily located if the original related print or metafile record uses an alternate edge fill mode. More specifically, it can be done by just selecting the odd and even segments on the scan-line and pairing them up respectively. If a record and its related polygonal specification use a winding-rule fill mode, the original drawing direction must be stored and the fill depth must also be tracked. FIG. 22 depicts the algorithm used here for finding segment pairs when a winding-rule fill mode is specified.
Segment pairs may change at each event point. For example, at event point A in FIG. 6( a ), segment pairs are {AB left , CD right } and {EF left , PQ right }. While at event point D in FIG. 6( b ), segment pairs are {AB left , PQ right } (i.e. the pair segment AB changes at different event points due to the winding rule fill mode).
The Segment Arrangement (SA) method described here determines at each “event point” whether an input segment should be eliminated, selected or duplicated based on metafile drawing and filling rules. Elimination means a segment that is drawn underneath other primitives will not be put into any segment pool. Selection means an original segment will be moved into a segment pool with similar attributes. Duplication means an original segment is copied into a segment pool with different attributes (where the copied segment then assumes the attributes of the pool into which it was copied). These three rules, shown in detail below constitute guidelines for the final arrangement algorithms. In general, segment selection and duplication are based on two factors: attribute values and age of the related polygonal object. A polygonal object is said to be younger if it appeared sequentially later within the list of metafile records. If a polygonal object is created earlier, it is considered older. For example, for differently colored objects, segments that are from younger objects may be selected and duplicated for those objects that are underneath or overlapped by them. These can be observed, in FIG. 7 , where object C is specified last and its segments will be selected and copied for object B.
Rules for Segment Elimination, Selection and Duplication are described as follows: Let S face (i) denote the face that is associated with segment S belonging to polygonal object i, where polygonal objects are ordered by their age. Note if j<i this indicates that the i th object is younger than the j th object. {SL i , SR i } denotes a segment pair where SL i denotes the left segment (of the pair) of the i th polygonal object at a specific event point and SR i denotes the right segment. According to the CGM filling method, the following selection and duplication rules are defined in order to separate the segments according to their attributes:
The “Elimination Rule” is defined as follows: if S j is between any segment pair {SL i ,SR i }, S j will be hidden in either of the following two cases: Case 1: j<i or Case 2: Attributes(S face (i))=Attributes(S face (j)). If S j is hidden, it will not be placed or duplicated into a segment pool.
The “Selection Rule” is defined as follows: S j will be moved to a segment pool in either of the following two cases: Case 1: S j is not inside or between any segment pair {SL i , SR i }, or Case 2: Of all segment pairs that S j lies between, let {SL i ,SR i } denote the youngest pair. If j>i and Attributes(S face (i))≠Attributes(S face (j)) S j will be moved.
The “Duplication Rule” is defined as follows: Of all segment pairs that Sj lies between, let {SL i ,SR i } denote the youngest pair. If j>i and Attributes(Sface(i))≠Attributes(Sface(j)), let S j ′ be the duplication of S j where Attributes(S′face(i)) are assigned Attributes(Sface(i)) and S j ′ is placed into the associated segment pool.
To further the operations of segment arrangement, an object stack is used to store active polygonal objects, where an object is considered to be active while scan lines continue to intersect with it. When the scan line hits the left segment of a segment pair, the object that is associated with that left segment is pushed on to the stack. Similarly, when the scan ray hits the right segment of a segment pair, the object associated with the right segment is popped off the stack.
Assuming a ray comes from infinity on the left and moves toward infinity on the right. Let S k denote a segment that intersects with the ray, where k=0, 1, . . . , n. At each event point, all segments are sorted from left to right (using the same method used previously for finding intersections) and stored in a queue. Therefore, S O is the left most segment, and S n is the right most segment.
It is not safe to assume that S O through S n do not overlap. It may be commonly found that many segments are coincident (i.e., share the same two end points). Such cases require additional bookkeeping and are discussed next. FIG. 23 delineates the general elimination, selection and duplication algorithm.
Lines 1 and 4 in FIG. 23 must be modified when several segments are coincident, because otherwise any one of these coincident segments could be arbitrarily or unpredictably hit first by the scan ray. In such cases, coincident segments are reordered and grouped into a “right group” and a “left group” where each group is then sorted. Specifically, Let S be the coincident segments which intersect with the scan ray. Let S left be the segments in S that belong to the left group (i.e. segments that are marked as the left segment within their corresponding segment pairs) and similarly, let S right be the remaining segments in S that are marked as right segments. S left and S right are then sorted by their related polygonal object's age (ascending order, youngest first). Let S m and S n denote the youngest segments within S left and S right respectively. Ø denotes an empty segment set. Thus, the modified segment arrangement criteria for the situation of multiple coincident segments are refined in FIG. 24 .
Note that in this special case, “Not Selected” implies “elimination”, therefore, the elimination criterion is omitted altogether. Additionally, according to these new coincident segment selection and duplication rules, S right will be processed first then S left . In the case of duplication, if there is at least one left segment and one right segment overlapping, even if they are not a segment pair, they will not be used for duplication. For selection, only the youngest left segment and youngest right segment will be selected. An example is illustrated in FIG. 8 . Let SR 2 SL 3 SR 4 SR 6 SL 7 SR 8 SL 8 SR 9 in FIG. 8( a ) be overlapping segments where their order represents their intersection sequence with the scan ray. In this case, only SR 9 and SL 8 will be selected if the related face attributes of SR 9 and SL 8 are different. However, if the attributes of SR 9 and SL 8 are identical, neither SR 9 nor SL 8 will be selected or copied.
After segment pools are populated, a Generate Composite Objects (GCO) method must execute to generate new resultant objects that represent the final composite shapes within the image. This method effectively builds new objects using the segments contained within each pool. As a segment pool may contain segments inherited from initially unrelated or differently attributed polygonal objects, there is no inherent linking or sequencing among them (other than obviously being placed within the same pool). Thus, a final step is to reconstruct a consistent and uniform traversal of such segments to indicate the boundaries of the one or more polygonal objects contained in a pool (i.e. so objects are comprised of an outer edge contour specified in counter clockwise vertex order and zero or more inner edge contours, indicating holes, specified in clockwise order). This is accomplished most efficiently by performing one final sweep-line process (using the rules below) on each pool to construct the appropriate contours as just described.
Rule 1: Segment traversal in each segment pool starts from an unvisited odd-segment at each event point where the even/odd attribute of a segment is determined as when alternate edge filling rules are applied. Each segment can only be visited once and all segments in the pool must be visited. For example, the arrowed lines in FIG. 10 indicate the starting segments at event points V 1 , P 1 and M 1 .
Rule 2: If there is an unvisited even numbered segment on the left of an odd numbered segment emanating from the same event point at the start of a traversal, the traversal path forms a hole. Oppositely, if the segment on the left of an odd numbered segment is visited, the traversal path forms the outer edge of a polygonal object (see example in FIG. 10 ).
Rule 3: At each vertex during traversal, if there are two or more edges unvisited, the leftmost edge is chosen if the traversal is along an outside boundary whereas the rightmost edge is chosen if it is a hole (as previously determined using rules 1 & 2). FIG. 11 shows how this rule is applied.
In addition to pool attributes (i.e. pool ID, color etc.), each segment is also associated with its twin segment which is stored in a different pool (analogous to the two half edges that comprise any edge). This association allows border information to be constructed for each object when a traversal is performed in each segment pool. More specifically, the twin segment's attributes are checked during the traversal. If the twin segment's attribute information is changed (e.g. the adjacent object with which this object borders has changed), the starting point of the edge is flagged as an “Adjacent Object Transfer Point.” And the border ID is set to is twin segment ID (where ID's are uniquely assigned to every resultant object generated). This border information basically specifies exactly where objects are touching or adjacent to other objects and can be quite useful when generating embroidery data. For example, to ensure solid registration (with no visible gap between adjacent objects) it may be useful to modify the embroidery generated for one object (appearing earlier in a sewing sequence) such that it extends or partially overlaps underneath another object to be sewn later in a sewing sequence only where the two objects are adjacent to one another. This will ensure that even if some visible shrinkage is present in the embroidered representation (i.e. due to stitch tension, etc.), the two objects will still be visibly adjacent to each other with no apparent gap. This auto-overlap type feature is difficult to facilitate if border information is not generated for each object.
After MC method is executed, embroidery primitive data generation can proceed by translating objects into specific embroidery stitching pattern. One embodiment of this method executes as disclosed in U.S. Pat. Nos. 6,397,120, 6,804,573, 6,836,695 and 6,947,808 where embroidery primitive control points are generated based on the geometric properties of the related shapes. Common border information (as mentioned above and referred to within the patents) further guides this process. After control points are generated, the actual x, y coordinates of stitch end points are produced by a stitch generation method. These end-points may then be easily reformed into any one of dozens of different proprietary machine file formats for viewing in editing programs or direct download for production on actual embroidery sewing equipment. | An example printer driver system and method disclosed herein includes determining a set of line segments corresponding to received image information, determining a first polygon from a first subset of the set of line segments, determining a second polygon from a second subset of the set of line segments, determining that a first line segment in the first subset and a second line segment in the second subset are collinear, removing the first line segment from the set of line segments, subtracting the first line segment from the second line segment to form a third line segment, replacing the second line segment in the set of line segments with the third line segment, determining a path corresponding to the set of line segments, determining a set of coordinates corresponding to the path, and instructing an embroidery machine to stitch the path in a substrate using the set of coordinates. | 3 |
REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/600,027 filed 17 Feb. 2012.
BACKGROUND
[0002] 1. Technical Field
[0003] The field relates to warning systems and more particularly to a locomotive mounted, directional, acoustic warning system.
[0004] 2. Description of the Problem
[0005] Train horns can either supplement or provide the only acoustic alarm at railway/road crossings. In the United States train horn use is regulated by the Federal Railroad Administration (FRA). Since 2005 regulations have provided that for trains moving slower than 45 mph the locomotive horn be sounded at least 15, but not more than 20, seconds before a locomotive enters a crossing. For trains moving faster than 45 mph the horn is to be sounded at designated locations. The train horn is to be sounded using is two long tones, a short tone and one additional long tone. This pattern is repeated until the lead locomotive has entered the crossing.
[0006] Despite the effectiveness of horns in giving warning to motorists and others, the use of horns in some areas is unpopular. The State of Florida attempted to ban the sounding of locomotive horns, but such a blanket prohibition ran afoul of federal preemption issues. Provisions have been made to allow local authorities an option of establishing quiet zones provided effective alternative safety measures are in place.
SUMMARY
[0007] A sound system for a ground vehicle comprises a line array of loudspeakers installed across the front of the ground vehicle. The line array is operated in a broadside firing mode to project a sound beam generally forward from the vehicle while allowing steering of the sound beam from side to side off center line. First and second loudspeakers are installed on the ground vehicle for projecting sound to the sides of the ground vehicle. A control system applies drive signals to the loudspeakers of the line array and to the first and second side loudspeakers. The control system provides phase adjustment of drive signals applied to each loudspeaker of the line array to control beam width and side to side directional steering of the sound beam relative to the direction of travel of the ground vehicle. The control system includes an automated, geographical location sensitive sub-system for selecting beam width and directional steering of a projected sound beam to be generated by the line array.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Understanding of the following description may be enhanced by reference to the accompanying drawings, wherein:
[0009] FIG. 1 is a side elevation of a locomotive on which a loudspeaker system has been installed as a substitute or supplement for an air horn system.
[0010] FIG. 2 is a top plan view of the locomotive of FIG. 1 illustrating the location of a front directed loudspeaker array and two side directed loudspeakers.
[0011] FIG. 3 depicts an operating scenario for the system.
[0012] FIG. 4 is a perspective view of the loudspeaker line array.
[0013] FIG. 5 is a cross sectional view of the loudspeaker line array.
[0014] FIG. 6 is a simple, theoretical polar plot for a directivity pattern for the front directed loudspeaker line array.
[0015] FIG. 7 is a graph illustrating frequency shading using a two speaker example.
[0016] FIG. 8 is a block diagram of a control arrangement for the loudspeaker system.
[0017] FIG. 9 is a high level flow chart for operation of the loudspeaker system.
[0018] FIG. 10 is a polar plot of acoustic radiation emitted at 350 Hz for the front directed loudspeaker line array.
[0019] FIG. 11 is a polar plot of acoustic radiation emitted at 400 Hz for the front directed loudspeaker line array.
[0020] FIG. 12 is a polar plot of acoustic radiation emitted at 500 Hz for the front directed loudspeaker line array.
[0021] FIG. 13 is a polar plot of acoustic radiation emitted at 630 Hz for the front directed loudspeaker line array.
[0022] FIG. 14 is a polar plot of acoustic radiation emitted at 800 Hz for the front directed loudspeaker line array.
[0023] FIG. 15 is a polar plot of acoustic radiation emitted at 1000 Hz for the front directed loudspeaker line array.
[0024] FIG. 16 is a polar plot of acoustic radiation emitted at 1250 Hz for the front directed loudspeaker line array.
[0025] FIG. 17 is a polar plot of acoustic radiation emitted at 1600 Hz for the front directed loudspeaker line array.
[0026] FIG. 18 is a polar plot of acoustic radiation emitted at 2000 Hz for the front directed loudspeaker line array.
[0027] FIG. 19 is a polar plot of acoustic radiation emitted at 2500 Hz for the front directed loudspeaker line array.
[0028] FIG. 20 is a polar plot of acoustic radiation emitted at 3150 Hz for the front directed loudspeaker line array.
[0029] FIG. 21 is a polar plot of acoustic radiation emitted at 4000 Hz for the front directed loudspeaker line array.
[0030] FIG. 22 is a polar plot of acoustic radiation emitted at 5000 Hz for the front directed loudspeaker line array.
[0031] FIG. 23 is a polar plot of all frequency components for the front directed loudspeaker line array.
[0032] FIG. 24 is a pressure and phase response plot against frequency for the front directed loudspeaker line array.
[0033] FIG. 25 illustrates delay against frequency for the line array.
[0034] FIG. 26 is an energy over time response over all frequencies for the line array.
[0035] FIG. 27 is a response curve for a single impulse input over time for the line array.
[0036] FIG. 28 is a response curve for a double impulse input over time for the line array.
[0037] FIG. 29 is a graph of total harmonic distortion for the line array in terms of percentage for each frequency band.
[0038] FIG. 30 is system frequency response with harmonic tracking overlay of second, third, fourth, fifth and sixth order distortion in decibels against frequency.
[0039] FIGS. 31-34 are directively patterns.
[0040] FIGS. 35-38 are exemplary directivity patterns.
[0041] FIGS. 39-45 are still further exemplary directivity patterns illustrating operation of the train mounted line array.
DETAILED DESCRIPTION
[0042] Referring to the figures, and particularly to FIGS. 1 and 2 , a ground vehicle such as a locomotive 10 is illustrated on which a loudspeaker system has been installed for the purpose of emitting acoustic warning of approach of the ground vehicle to a location, particularly locations adjacent a level grade road crossing with railroad tracks. The loudspeaker system comprises a forward directed loudspeaker line array 12 and first and second side directed loudspeakers 14 and 16 . The line array 12 is positioned horizontally with respect to the tracks supporting the locomotive and has a primary or neutral sound projection axis aligned on the longitudinal axis of the locomotive 10 . The first and second side directed loudspeakers 14 and 16 oriented to project sound away from the right and left sides of locomotive 10 . The front directed loudspeaker line array 12 and the side directed loudspeakers 14 , 16 are mounted on top of the locomotive 10 to provide unobstructed projection of sound.
[0043] A loudspeaker line array 12 is illustrated in FIGS. 4 and 5 . Loudspeaker line array 12 comprises at least three loudspeakers 13 A, 13 B and 13 C. Traditionally air horns have been used on locomotives in order to obtain the desired sound level output. The present applicant has submitted an application for an electro/acoustical transducer system utilizing opposed transducers directed into a waveguide assembly entitled RADIAL WAVEGUIDE FOR DOUBLE CONE TRANSDUCER, U.S. patent application Ser. No. 13/346,077 filed 9 Jan. 2012, which is incorporated herein by reference. Transducer and waveguide assemblies such as disclosed in the incorporated application may be utilized for the loudspeakers 13 A-C of line array 12 and for side directed loudspeakers 14 and 16 . This device is sometimes referred to herein as a “Tandem Horn.”
[0044] Loudspeaker line array 12 is constructed with its center loudspeaker 13 B which, when mounted on a locomotive 10 , is intended to be directed straight ahead aligned on the longitudinal axis of the locomotive 10 . Outboard loudspeakers 13 A, 13 C are canted outwardly away from the longitudinal axis of the locomotive 10 and located slightly behind the center loudspeaker 13 B making the line array a gently curved or staggered line array. Gently curved line arrays are known from several sources including U.S. Patent Application Publication No. 2008/0212805 (a symmetric system) and U.S. Pat. No. 6,870,942 (a non-symmetric system). Line array 12 is disposed on the locomotive 10 with its axis of elongation generally parallel to the ground, or more precisely, generally parallel to the local plane of the tracks that the locomotive 10 rides on. The acoustic centers of adjacent loudspeakers are spaced from one another by about 18 inches.
[0045] Referring to FIG. 3 a locomotive 10 located on a railroad track 18 is equipped with a forward directed loudspeaker array 12 . Locomotive 10 is shown in a position along an approach to a level grade crossing 28 of a road 30 with track 18 . The approach path of the locomotive 10 to the level grade crossing 28 is not along a straight line as a bend 34 in the tracks 18 occurs between the location of the crossing guard triggers 24 and the level grade crossing 28 . The locations of vehicles and pedestrians along their respective lines of approach to the level grade crossing 28 , that is on or along road 30 , may vary from straight ahead of the locomotive 10 to locations well of the longitudinal axis of the locomotive. Approach of a locomotive 10 to the region into which a warning is to be broadcast by the locomotive horn system may not be straight for reasons other than bends in the tracks 18 . For example, the road or path crossing the tracks 18 may incorporate turns and/or cross the tracks at other than a perpendicular angle and the angle may change either away from or closer to the center line of the locomotive 10 as it approaches. In addition, the speed at which the locomotive 10 is traveling affects the timing of sounding of an alert from the locomotive. A car 31 is located on the road 30 approaching level grade crossing 28 short of a flasher/bell warning system 32 to illustrate a possible location where sound energy is to be directed.
[0046] Under normal circumstances, upon locomotive 10 passing crossing guard triggers 24 , signals are sent along a crossing guard trigger cable 26 to an automatic crossing guard controller 20 which controls activation of the flasher/bell warning system 32 . This system can be used to trigger operation of a crossing guard transponder 22 which can transmit data to or be interrogated by a control system on locomotive 10 for reports on operating condition of the flasher/bell warning system 32 . Crossing guard transponder 22 may be equipped to provide local weather conditions, particularly wind direction and speed at the level grade crossing 28 . Crossing guard transponder 22 may be locally programmed to provide special instructions or a beam profile to an approaching locomotive 10 as described below.
[0047] Forward directed loudspeaker line array 12 can serve to supplement the flasher/bell warning system 32 by emulating a train horn targeting the approaches to level grade crossing 28 . Line arrays compress sound emitted from the array into a primary/major and secondary lobes extending radially from the line array 12 in a plane parallel to the ground and aligned on the locomotive, assuming no beam steering. The horizontally disposed array allows the primary/major lobe or beam of sound from the array to be steered in the horizontal plane parallel to the ground using techniques of phase adjustment, amplitude shading and frequency shading among the loudspeakers 13 A-C of the line array 12 . Confining most sound energy to lobes, and controlling the direction and width of the lobes can be used to reduce sound spill over into areas away from the approaches to the level grade crossing 28 , compensating for bends 34 in the track 18 , or non-perpendicular approaches of roads 30 ton the tracks.
[0048] FIG. 6 illustrates a simple directivity pattern 38 at a particular frequency for forward directed loud speaker line array 12 . The line array 12 is set for broadside firing with a minimum of phase adjustment and frequency and amplitude shading. Directivity pattern 38 is in a plane to the ground with the central projection axis/major lobe and back lobe usually aligned on the longitudinal axis of locomotive 10 . The major lobe can be displaced in either direction outwardly (but parallel to the ground) from the locomotive's longitudinal axis by beam steering. The spread of the major lobe to −10 dB may be varied by adjusting phase differences between the loudspeakers of the line array 12 .
[0049] While the primary beam lobe is normally set for a narrow beam of 42-45 degrees (about 22 and ½ degrees each side of center) at the primary frequency, for an emergency condition such as a vehicle on the track the beam could be actively focused the a minimum beam waist and steered directly at the target to create the maximum available acoustic power to the target. Video or radar could be used to determine precise location bearing to the target and processing applied to deliver maximum energy density to the selected target(s)
[0050] The primary beam lobe emulates the sound pressure of a standard pneumatic train horn, however the substantial decrease in acoustic sound power at all angles of the system other than the primary beam lobe decrease the noise pollution to surrounding areas. Additional settings (enhancements) of the signal processing allow the array system to have additional decreased output to the null areas where sound energy is to be minimized due to the proximity of houses and businesses. In testing average side attenuation of −18 to −24 db from the primary beam lobe was achieved, however alternative DSP settings produced attenuation levels as great as −42 db from the primary beam lobe in portions of the acoustic spectrum.
[0051] The ability to program waveforms allows for high contrast ratio lower duty-cycle alert tones could be mixed with the train 5 tone sounds to create a louder and higher percentage attention getting signal for use in conditions where the standard train horn sounds are ineffective. In addition, selectable “engineered per species” sound tracks could be chosen to directly deter wildlife from the front of the trains path in the case of obstruction of the tracks. A secondary passive noise absorption housing can be applied to the system to lower the side/rear emission levels even beyond the adaptive null created with the array. The system can be operated via remote location via live data links and or operated in an autonomous response mode eliminating the requirements of a live systems operator on-board.
[0052] Focusing sound energy from the front directed loudspeaker line array 12 into lobes avoids spillover into areas adjacent the tracks where the sound is not needed and beam steering allows sound energy to be directed to compensate for level grade crossings which are non-standard. The provision of side directed loudspeakers 14 , 15 , which are not installed in arrays and are less directional than the array allows sound to be directed more to the sides of the locomotive 12 . Active steering (left-center-right-center-left etc.) of the main primary acoustic lobe would allow the system to produce a sound in motion effect that would increase the attention getting capability of the system for emergency operations. Increasing the number of loudspeakers in array 12 provided greater control over beam steering and lobe spreading.
[0053] In a test arrangement an array 12 was built with a mechanical splay angle was set at 35 degrees so center horn was at 0 degrees with the left side horn set at 35 degrees to center and the right side at 35 degrees to center. A 42 degree beam was formed when the center horn was phase delayed 0.318 ms from the outside horns. A 60 degree beam was formed when the center horn was phase delayed 0.120 ms from the outside horns. A 85 degree beam was formed when the center horn was phase delayed 0.060 ms from the outside horns. A 120 degree beam was formed when the outside horns were phase delayed 0.298 ms from the center horn. A 198 degree beam was formed when the outside horns were phase delayed 0.918 ms from the center horn. A right steered beam of 20 degrees was formed with a left phase delay 0.00 ms, center 0.121 ms, right 0.815 ms setting.
[0054] FIG. 7 illustrates frequency shading for a pair of loudspeaker with the output amplitude for one speaker ramped up to a plateau between 300 Hz and 10 KHz and another loudspeaker having a more gradual ramp up to the plateau from below 1 KHz.
[0055] FIG. 8 is a block diagram for a control system for side directed loudspeakers 14 , 16 and front directed loudspeaker line array 12 . An on board computer or matrix select controller 40 generates/supplies selected audio input signals to each loudspeaker channels 60 A-E. The audio input signal may be virtually any signal including frequencies in the human range of hearing, but usually includes a frequency mix which emulates a train horn or captures a voice input. Each of channels 60 A-E is physically substantially identical, however, channels 60 A-C, which drive loudspeakers 13 A-C, are operated in a coordinated manner to provide that the loudspeakers operate as a generally broad side firing array with beam steering. Signals applied to loudspeakers 13 A-C are generally identical, but phase shifted with respect to one another to achieve line array operation with beam steering.
[0056] Each of channels 60 A-E comprises a digital signal processor 61 , an amplifier 63 and a loudspeaker, respectively loudspeakers 13 A-C, 14 and 16 . Matrix select controller 40 directs generation of a sound output either automatically or in response to operator interaction with the system using a graphical user interface 44 and, possibly, a local audio input 42 (such as a microphone). Generally only the lead locomotive of a tandem pair of locomotives 10 is allowed to use its loudspeakers, or at least its forward directed loudspeaker line array 12 . Accordingly a slave/master circuit 45 is provided which supplies an enable/disable signal to the matrix select controller 40 depending upon whether a particular locomotive is the lead or a trailing machine.
[0057] Matrix select controller 40 may be programmed to respond to other inputs. Proximity sensor 58 may be a short range radar unit located with respect to the loudspeakers 13 A-C, 14 and 16 which generates a disable/degrade signal in case a person is located in close proximity to the mouth of the waveguide from a loudspeaker unit. Output from a unit can be blocked or limited to prevent hearing damage to an individual standing in proximity to the unit. A telematics receiver unit 46 may be connected to the matrix select controller 40 . Telematics units may be used to allow matrix select controller 40 to access geographic information system databases and maps allowing it to locate and characterize level grade crossings which the locomotive 10 is approaching. It may also be used to provide location information to the matrix select controller 40 as may a global positioning system (GPS) unit 50 installed on the locomotive 10 and connected to provide location data to the matrix select controller 40 .
[0058] Timing of generation of a warning signal using the loudspeaker system of locomotive 10 depends on the speed and route which the locomotive is traveling. A speed signal source 48 may be provided or speed may be determined by GPS unit 50 . The output generated by the system may be adjusted depending upon weather conditions 52 , particularly wind direction, which can affect beam steering. Transponder trigger unit 54 communicates with crossing guard transponder 22 (if available) to determine if local conditions might be otherwise than indicated in the data base/look up table (LUT) 57 stored in memory 56 .
[0059] Memory 56 , and the LUT 57 relating to level grade crossings, is of particular relevance to control over the audio channels 60 A-E. The database/LUT for level grade crossings is indexed by location and can include a topology classification, a risk factor index, a beam form type to use and a direction for aiming the beam/major lobe produced by the array 12 (which may be adjusted for wind). The beam profile to use may be further defined by amplitude to use, modulation and wafting of the signal. Alternatively, local transponders 22 may broadcast a crossing guard classification enabling the database to simply provide a beam profile to use for the general classification.
[0060] Once matrix select controller 40 has identified from a specific level grade crossing entry or type categorization a beam profile and warning alert type to use, and ambient conditions and locomotive 10 speed obtained, a configuration for each DSP 61 is available. The DSP configuration for each of channels 60 A-E determines if a given channel is used at all, the delay for each channel, frequency shading filters to be implemented by each DSP to obtain a selected beam width and a gain for each channel's amplifier 63 . A compressor limit may be implemented to shape audio waveforms to create higher average sound without exceeding peak to peak limits of the system. Signal strength can also be enhanced through other well known techniques such as passing more low frequency power (at the cost of beam spreading) or altering the harmonic content to affect human perception of the sound.
[0061] The active DSP system 61 for each horn could be replaced by modified “canned” tracks of the signal with the DSP filters applied to the waveform fed each respective horn. This would have the same effect as an active DSP but utilize independent processed and filtered tracks emulating the active DSP function without requiring the control DSP processing onboard.
[0062] The flow chart of FIG. 9 is a broad, high level depiction of this operation, occurring upon arming of the system by an operator at step 80 . At step 82 the matrix select controller 40 determines if the system is in automatic or manual mode. If manual an audio input signal can be buffered at step 84 . Next the presence of a trip condition, such as provided by proximity sensor 58 is checked for. If a trip condition is detected the operator is alerted (step 90 ) using the GUI 44 and operation returns to step 84 to continue buffering until the trip condition is cleared and the sound can be generated (step 88 ).
[0063] Under automatic mode it may be determined if the locomotive is a leader(master) or follower (slave), step 92 ). As long as the unit is a slave it may be disabled by looping the test. If the unit is a master its operational status is displayed (step 94 ) and approach to a level grade crossing is monitored, as may be indicated by a receiving a response to a transponder signal (step 96 ). Alternatively, GPS unit 50 may be used for this function through use of location signals to continually interrogate the LUT 58 for a match. Once approach to an crossing is indicated ambient conditions are read (step 98 ), speed of approach to the crossing is determined (step 100 ), the LUT 58 is interrogated to fetch the proper alert (step 102 ) and the several DSP units 61 have configurations set (step 104 ) allowing the audible warning signal to be generated (step 106 ) and the process loops back to step 96 .
[0064] FIGS. 10-22 are polar plots relating to directivity data and frequency response of line array 12 taken at a plurality of frequencies, particularly 315 Hz, 400 Hz, 500 Hz, 630 Hz, 800 Hz, 1000 Hz, 1250 Hz, 1600 Hz, 2000 Hz, 2500 Hz, 3150 Hz, 4000 Hz, 5000 Hz. FIG. 23 is a composite view. A more distinct front directed major lobe appears with increasing frequency.
[0065] FIG. 24 is a pressure and phase response plot against frequency for the front directed loudspeaker line array 12 . The plots were generated from 1024 samples in 5.5 seconds. The frequency resolution was 35.1 Hz and the time resolution was 28.46 ms (32.16 feet).
[0066] FIG. 25 plots group delay against frequency at the same resolutions used in FIG. 24 .
[0067] FIG. 26 is an energy over time response over all frequencies for the line array.
[0068] FIG. 27 is a response curve for a single impulse input over time for the line array.
[0069] FIG. 28 is a response curve for a double impulse input over time for the line array.
[0070] FIG. 29 is a graph of total harmonic distortion for the line array in terms of percentage for each frequency band.
[0071] FIG. 30 is system frequency response with harmonic tracking overlay of second, third, fourth, fifth and sixth order distortion in decibels against frequency.
[0072] FIGS. 31 through 34 illustrate directivity of a free standing horn loaded loudspeaker such as loudspeakers 14 , 16 , or of line array 12 where only one loudspeaker is operated, such as loudspeaker 13 B at the frequencies of 250, 500, 1000 and 2000 Hz.
[0073] FIGS. 35 through 38 illustrate directivity patterns over the same set of frequencies, 250 through 2000 Hz for line array 12 with all of loudspeakers 13 A-C receiving the same drive signals. The drive signal applied to the center loudspeaker 13 B is delayed by 1 millisecond in the bottom view for each frequency set. A delay is analogous to a phase delay except that the phase delay increases for each drawing pair due to the increasing drive signal frequency. Results at 500 and 1000 Hz indicate generation of extra lobes with suppression of a straight ahead primary lobe at 500 Hz.
[0074] FIGS. 39 through 45 illustrate the use of delay and amplitude and/or frequency shading to shape sound lobes from a line array 12 and to steer the resulting lobes/beams. FIG. 39 is a pair of polar graphs with baselines for the top directivity pattern at 1000 Hz and at 500 Hz, respectively. FIG. 40 includes three directivity patterns. The top pattern is a pattern for a horn emission frequency of 250 Hz with center horn loaded loudspeaker 13 B of the line 12 delayed 1.1 milliseconds. The middle and bottom patterns are for 250 and 500 Hz. At 250 Hz the line array 12 exhibits a pronounced forward lobe, two side directed lobes and a very small rearward lobe. At 500 Hz the rearward directed lobe substantially disappears and the pair of left and right side lobes are folded forward and gain intensity. The forward major lobe is attenuated in comparison.
[0075] FIG. 41 relate to directivity patterns at 1000 Hz (top) and 500 Hz (bottom) with differentiated delays applied to the center and the rightside of the side loudspeakers relative to the remaining side loudspeaker, respectively. The delays are 0.5 & 1 ms. At 500 Hz the lobes are canted to the left and the right most lobe increases in strength relative to the left and forward lobes.
[0076] FIG. 42 is labeled “steered+−6 −3 shading.” The directivity pattern is for an emission frequency of 500 Hz and reflect 0.5 millisecond and 1.0 millisecond delays to the center and right loudspeakers of a three speaker line array 12 . The output of the center and left loudspeakers is attenuated. The center speaker is attenuated −6 db and the left loudspeaker is attenuated −3 db. In FIG. 43 the attenuation is increased −9 db for the center and −6 db for the left. This illustrates the use of selective amplitude shading to achieve substantial lobe steering and shaping.
[0077] FIG. 44 is labeled “steered+−12 −9 shading.” It is also for 500 Hz. The center loudspeaker is attenuated by −12 db and the left by −9. The phase relationship is set by a center 0.5 msec delay and a right speaker delay of 1 msec. In FIG. 45 the center loudspeaker is attenuated by −9 db and the left loudspeaker is shut off. There is no delay of the right loudspeaker with respect to the left. | A sound system for a locomotive mounts a loudspeaker line array for broadside firing forward from the vehicle. Additional loudspeakers are installed on the locomotive for projecting sound to the sides. A control system applies drive signals to the loudspeakers of the line array with the control system providing phase adjustment of drive signals applied to each loudspeaker of the line array to control side to side directional steering of a projected sound beam. The control system includes an automated, location dependent sub-system for selecting beam width and directional steering of a projected sound beam. | 1 |
FIELD OF THE INVENTION
This invention relates in general to tools for running casing hangers in subsea wells, and in particular to a high capacity tool that sets and internally tests a casing hanger packoff in one trip.
BACKGROUND OF THE INVENTION
A subsea well of the type concerned herein will have a wellhead supported on the subsea floor. One or more strings of casing will be lowered into the wellhead from the surface, each supported on a casing hanger. The casing hanger is a tubular member that is secured to the threaded upper end of the string of casing. The casing hanger lands on a landing shoulder in the wellhead, or on a previously installed casing hanger having larger diameter casing. Cement is pumped down the string of casing to flow back up the annulus around the string of casing. Afterward, a packoff is positioned between the wellhead bore and an upper portion of the casing hanger. This seals the casing hanger annulus.
Casing hanger running tools perform many functions such as running and landing casing strings, cementing strings into place, and installing and testing packoffs. Testing the packoff is traditionally performed by pressuring under the blow out preventer (BOP) stack, but more recent casing hanger running tool designs incorporate an “internal” or “down the drill pipe” test which isolates the test pressure to a small volume just above the hanger. An internal test has several benefits including reducing the annular pressure end load reacted against the hanger and making leak detection more direct, which is especially beneficial for sub-mudline casing strings which can be located several thousand feet from the BOP stack. The cost of the added functionality is complexity in the form of additional ports and seals.
Virtually all casing hanger running tools to date incorporate a cam that acts as a mechanical program for the tool. Rotational inputs to the cam drive it axially, causing it to drive engaging elements such as dogs radially, allows seal-setting pistons to communicate with the stem, and opens up additional ports for internal testing. Typically, cams occupy the radial space between the stem and the body of the running tool and must be thick enough to withstand radial loads generated by the dogs and pressure loads from setting and testing packoffs. If the cam could be eliminated, the radial space it normally occupied could be used to thicken up the body and the stem, thus increasing the hanging capacity of the tool. A need exists for a technique that addresses increased hanging capacity of a running tool, coupled with the ability to internally test a packoff. The following technique may solve one or more of these problems.
SUMMARY OF THE INVENTION
In an embodiment of the present technique, a high capacity running tool sets and internally tests a casing hanger packoff during the same trip. The running tool is comprised of a body and a stem. The body is secured by threads to the stem of the running tool so that rotation of the stem relative to the body will cause the stem to move longitudinally. An engagement element connects the tool body to the casing hanger by engaging an inner surface of the casing hanger. Longitudinal movement of the stem relative to the body moves the engaging element between an inner and outer position, thereby securely engaging the running tool and the casing hanger. Longitudinal movement of the stem relative to the body also lines up ports in the stem and the body for setting and testing functions, much like a cam in previous running tools.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a high capacity running tool constructed in accordance with the present technique with the piston cocked and the engagement element retracted.
FIG. 2 is a sectional view of the high capacity running tool of FIG. 1 in the running position with the engagement element engaged.
FIG. 3 is a sectional view of the high capacity running tool of FIG. 1 in the setting position.
FIG. 4 is a sectional view of the high capacity running tool of FIG. 1 in the seal testing position.
FIG. 5 is a sectional view of the high capacity running tool of FIG. 1 in the unlocked position with the engagement element disengaged.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , there is generally shown an embodiment for a high capacity running tool 11 that is used to set and internally test a casing hanger packoff. The high capacity running tool 11 is comprised of a stem 13 . Stem 13 is a tubular member with an axial passage 14 extending therethrough. Stem 13 connects on its upper end to a string of drill pipe (not shown). Stem 13 has an upper stem port 15 and a lower stem port 17 positioned in and extending therethrough that allow fluid communication between the exterior and axial passage of the stem 13 . A lower portion of the stem 13 has threads 19 in its outer surface. The outer diameter of an upper portion of stem 13 is greater than the outer diameter of the lower portion of stem 13 containing threads 19 . As such, a downward facing shoulder 21 is positioned adjacent threads 19 . A recessed pocket 23 is positioned in the outer surface of the stem 13 at a select distance above the downward facing shoulder 21 .
Running tool 11 has a body 25 that surrounds stem 13 , as stem 13 extends axially through the body 25 . Body 25 has an upper body portion 27 and a lower body portion 29 . The upper portion 27 of body 25 is a thin sleeve located between an outer sleeve 30 and stem 13 . Outer sleeve 30 is rigidly attached to stem 13 . A latch device (not shown) is housed in a slot 32 located within the outer sleeve 30 . The lower body portion 29 of body 25 has threads 31 along its inner surface that are engaged with threads 19 on the outer surface of stem 13 . Body 25 has an upper body port 33 and a lower body port 35 positioned in and extending therethrough that allow fluid communication between the exterior and interior of the stem body 25 . The lower portion 29 of body 25 houses an engaging element 37 . In this particular embodiment, engaging element 37 is a set of dogs having a smooth inner surface and a contoured outer surface. The contoured outer surface is adapted to engage a complimentary contoured surface on the inner surface of a casing hanger 39 when the engagement element 37 is engaged with the casing hanger 39 . Although not shown, a string of casing is attached to the lower end of casing hanger 39 . The inner surface of the engaging element 37 is initially in contact with the threads 19 on the inner surface of stem 13 .
A piston 41 surrounds the stem 13 and substantial portions of the body 25 . Referring to FIG. 3 , a piston chamber 42 is formed between upper body portion 27 , outer sleeve 30 , and piston 41 . Piston 41 is initially in a and upper or “cocked” position relative to stem 13 , meaning that the area of piston chamber 42 is at its smallest possible value, allowing for piston 41 to be driven downward. A piston locking ring 43 extends around the outer peripheries of the inner surface of the piston 41 . Locking ring 43 works in conjunction with the latch device (not shown) contained within outer sleeve slot 32 to restrict movement of the piston during certain running tool functions. A casing hanger packoff seal 45 is carried by the piston 41 and is positioned along the lower end portion of piston 41 . Packoff seal 45 will act to seal the casing hanger 39 to the wellbore (not shown) when properly set. While piston 41 is in the upper or “cocked” position, packoff seal 45 is spaced above casing hanger 39 .
A dart landing sub 47 is connected to the lower end of stem 13 . The landing sub 47 will act as a landing point for an object, such as a dart, that will be lowered into the stem 13 . When the object or dart lands within the landing sub 47 , it will act as a seal, effectively sealing the lower end of stem 13 .
Referring to FIG. 1 , in operation, the high capacity running tool 11 is initially positioned such that it extends axially through a casing hanger 39 . The piston 41 is in a “cocked” position, and the stem ports 15 , 17 and body ports 33 , 35 are axially offset from one another. Casing hanger packoff seal 45 is carried by the piston 41 . The running tool 11 is lowered into the casing hanger 39 until the outer surface of the body 25 of running tool 11 slidingly engages the inner surface of casing hanger 39 .
Referring to FIG. 2 , once the running tool 11 and casing hanger 39 are in abutting contact with one another, the stem 13 is rotated four revolutions. As the stem 13 is rotated relative to the body 25 , the stem 13 and piston 41 move longitudinally downward relative to body 25 . As the stem 13 moves longitudinally, the shoulder 21 on the outer surface of stem 13 makes contact with the engaging element 37 , forcing it radially outward and in engaging contact with the inner surface of casing hanger 29 , thereby locking body 25 to casing hanger 39 . As stem 13 moves longitudinally, stem ports 15 , 17 and body ports 33 , 35 also move relative to one another.
Referring to FIG. 3 , once the running tool 11 and casing hanger 39 are locked to one another, the running tool 11 and casing hanger 39 are lowered down the riser into the subsea wellhead housing (not shown) until the casing hanger 39 comes to rest. Referring to FIG. 3 , a solid dart 49 is then dropped or lowered into the axial passage 14 of stem 13 . The solid dart 49 lands in the landing sub 47 , thereby sealing the lower end of stem 13 . The stem 13 is then rotated four additional revolutions in the same direction. As the stem 13 is rotated relative to the body 25 , the stem 13 and piston 41 move further longitudinally downward relative to body 25 and casing hanger 39 . As the stem 13 moves longitudinally, stem ports 15 , 17 and body ports 33 , 35 also move relative to one another. Upper stem port 15 aligns with upper body port 33 , but lower stem port 17 is still positioned above lower body port 35 . This position allows fluid communication from the axial passage 14 of stem 13 , through stem 13 , into and through body 25 , and into piston 41 . Fluid pressure is applied down the drill pipe and travels through the axial passage 14 of stem 13 before passing through upper stem port 15 , upper body port 33 , and into chamber 42 , driving piston 41 downward relative to the stem 13 . As the piston 41 moves downward, the movement of piston 41 sets the packoff seal 45 between an outer portion of casing hanger 39 and the inner diameter of the subsea wellhead housing.
Referring to FIG. 4 , once the piston 41 is driven downward and packoff seal 45 is set, the stem 13 is then rotated four additional revolutions in the same direction. As the stem 13 is rotated relative to the body 25 , the stem 13 moves further longitudinally downward relative to body 25 and casing hanger 39 . Stem 13 also moves downward at this point relative to piston 41 . As the stem 13 moves longitudinally, stem ports 15 , 17 and body ports 33 , 35 also move relative to one another. Lower stem port 17 aligns with lower body port 35 , allowing fluid communication from the axial passage 14 of stem 13 , through stem 13 , into and through body 25 , and into an isolated volume above packoff seal 45 . Upper stem port 15 is still aligned with upper body port 33 . The latch device located with the slot 32 on the outer sleeve 30 is activated by the movement of the stem 13 and will act in conjunction with piston locking ring 43 to restrict the upward movement of piston 41 beyond the latch device. Pressure is applied down the drill pipe and travels through the axial passage 14 of stem 13 before passing through lower stem port 15 , lower body port 33 , and into an isolated volume above packoff seal 45 , thereby testing packoff seal 45 . The same pressure is applied to piston 41 , creating an upward force, however, movement of the piston 41 in an upward direction is restricted by the engagement of the piston locking ring 43 and the latch device (not shown) positioned in the slot 32 on outer sleeve 30 . In an alternate embodiment, the size of the fluid chambers in the piston 41 and seal 45 areas could be sized such that the larger sized fluid chamber in the seal 45 area maintains a downward force on piston 41 , thereby eliminating the need for the latch device and the piston locking ring 43 . An elastomeric seal 51 is mounted to the exterior of piston 41 for sealing against the inner diameter of the wellhead housing. Seal 51 defines the isolated volume above packoff seal 45 . If packoff seal 45 is not properly set, a drop in fluid pressure held in the drill pipe will be observed as the fluid passes through the seal area.
Referring to FIG. 5 , once the packoff seal 45 has been tested, the stem 13 is then rotated four additional revolutions in the same direction. As the stem 13 is rotated relative to the body 25 , the stem 13 moves further longitudinally downward relative to the body 25 , casing hanger 39 , and piston 41 . As the stem 13 moves longitudinally downward, the engagement element 37 is freed and moves radially inward into recessed pocket 23 on the outer surface of stem 13 , thereby unlocking the body 25 from casing hanger 39 . Upper stem port 15 remains aligned with upper body port 33 . Lower stem port 17 remains aligned with lower body port 35 . The lower stem port 17 and lower body port 35 vent the column of fluid in the drill pipe, allowing dry retrieval of the running tool 11 . Running tool 11 can then be removed from the wellbore.
The technique has significant advantages. The elimination of a cam provides fewer leak paths and an increased hanging capacity due to the increase radial space within the running tool.
While the technique has been shown in only one of its forms, it should be apparent to those skilled in the art that it is not so limited but is susceptible to various changes without departing from the scope of the technique. | A high capacity running tool sets and internally tests a casing hanger packoff during the same trip. The running tool has a stem and a body. The body is secured by threads to the stem of the running tool so that rotation of the stem relative to the body will cause the stem to move longitudinally. An engagement element connects the tool body to the casing hanger by engaging the inner surface of the casing hanger. Longitudinal movement of the stem relative to the body moves the engaging element between inner and outer positions and lines up ports in the stem and in the body for setting and testing functions. | 4 |
BACKGROUND
1. Field of Invention
The invention relates to a novel water, energy, and time efficient reactive rapid dyeing process for the dyeing of cellulosic containing textile materials with fiber reactive dyestuffs whereby from scour through after-scour a total process time of less than 5 hours are employed and only from 5 to 6 liquor baths are required.
2. Description of Prior Art
Numerous processes have heretofore been utilized for the dyeing of textile materials such as fibers, yarns and fabrics with wide divergence among the process parameters, depending upon the particular material being dyed, and the particular type of dyestuff being employed. Of particular importance are processes that have been utilized to dye cellulosic textile materials with fiber reactive dyes.
In utilizing the conventional fiber reactive dyeing process, not only is the dyeing operation expensive and time consuming, but the process is particularly energy intensive. With different baths, sometimes as many as 12 or 14, substantial energy is expended for raising the bath temperature from ambient to elevated temperature conditions at several intervals during the process. Moreover considerable rework is necessary due to shade variability and unlevel dyeings due to strike rate and hydrolysis of reactive dyes and unnecessary dyestuffs and chemicals are therefore wasted in larger amounts; and the protracted length of time required to complete the dyeing reduces the production capacity of the dyeing equipment.
Presently, the availability of energy adequate to run energy intensive dyeing operations is of major concern, not to mention the tremendous cost of same. Consequently much effort has been devoted to improving dyeing processes, attempting to reduce energy requirements necessary for the dyeing of all materials, particularly cotton and viscose rayon with fiber reactive dyes which are notoriously expensive and time consuming using state of art techniques.
Heretofore, many different processes have been proposed for the dyeing of cellulose containing materials with fiber reactive dyes, although most of the work has been done on the dyeing part of the process, not much work has been done on the approach of involving the scouring, the dyeing, and the after-scouring as a one process per se. For example,
U.S. Pat. No. 5,356,444 to Schwarz, Max; Wolff, Joachim; Hildebrand, Dietrich; Grutze, Joachim; Hoppe, Manfred; Stawitz, Josef-Walter; Schulz, Rolf (Oct. 18, 1994)
Bayer Aktiengesellschaft recommends the following conventional fiber reactive dyeing and after-scouring procedure from the Prior Art U.S. Pat. No. 5,356,444:
100 parts of bleached cotton knitted goods and 3 parts of a phthalocyanine reactive dyestuff mixture are added to 1000 parts of aqueous dye liquor on a winch vat at 60 degrees C.
After the dyestuff mixture has become uniformly distributed in the liquor and on the cotton over a period of 15 minutes, 50 parts of sodium chloride are introduced into the dye liquor over a period of 30 minutes and 10 parts of sodium carbonate are then added at intervals of 10 minutes as 3 portions respectively comprising 1 part, 2 parts and 7 parts. The batch is then heated to 80 degrees C. in the course of 30 minutes and the goods are treated at this temperature for 30 minutes. After cooling, the liquor is then drained off and the goods are rinsed twice at 60 degrees C. and twice at 80 degrees C. They are then extracted at the boil for 15 minutes and the wash liquor is dried off. After cold rinsing, a level turquoise dyeing with good fastness properties is obtained.
It can be seen from the above-mentioned example that the electrolyte is dosed in a time period of 30 minutes, and that the alkali is also dosed in a time period of 30 minutes. In addition, six baths are used for the after-scouring with a combined temperature raise of 255° C.
U.S. Pat. No. 4,359,322 to Neal, Bobby L.; Lowman,Steven R. (Nov. 16, 1982)
On the pre-scour operation of the goods, according to Neal in the Prior Art on U.S. Pat. No. 4,359,322, the goods are taken to 212° F. (100° C.), and run 30 to 45 minutes at said temperature, several rinses and an acid sour at 1 20° F. (50° C.), that is to say a total of 5 baths just for the pre-scour operation.
U.S. Pat. No. 5,364,416 to Schwarz, Max; Grutze, Joachim; Hildebrand, Dietrich; Wolff, Joachim; Stohr, Frank-Michael (Nov. 15, 1994)
Conventional after-scouring procedures are time consuming, energy intensive and of very high water consumption and effluents, as can be observed from the Prior Art U.S. Pat. No. 5,364,416 where after the dyeing procedure 2 warm water rinses at 50° C., 2 hot water rinses at 80° C., soaping at the boil for 15 to 20 minutes with suitable detergent, and cold water rinses until water is clear are performed in order to achieve good wash-fastness properties from a 2% fiber reactive dyed material, that is a total of seven water baths just for the after-scouring operation, plus a combined temperature rise of 235° C.
U.S. Pat. No. 5,554,199 to Baumann; Hans-Peter (Sep. 10, 1996)
It is of common practice to add the alkali fixing dyestuff agent in several parts and at 5 to 10 minutes intervals during dyeing, as stated by Baumann in the Prior Art U.S. Pat. No. 5,554,199, where as stated in Application Examples A and B, after waiting a 30 minute period for the dyestuff exhaustion to take place, 5 additions of alkali at 5 minute intervals are made; the problem with this procedure being that its very hard to achieve perfect lot-to-lot color repetition, different strike rates causing shade variability and increasing undesirable reworks plus the fact that its time consuming.
U.S. Pat. No. 5,833,720 to Kent, Johnny Joe; Lee, Eric C. S.; Yu, Sui-Fung (Nov. 10, 1998)
Just on the preparation of the fabrics, according to Kent et al. in Prior Art U.S. Pat. No. 5,833,720, four full water baths are used, and while the temperature was set to 70° C. and was held for 30 minutes, its well known to all skilled in the art that a much more efficient preparation of cotton materials take place at the boil.
In addition, according to the Prior Art U.S. Pat. No. 5,833,720, the energy efficient dyeing process works only with bifunctional reactive dyes, which is a big limitation to their dyeing process, since all the other type of fiber reactive dyestuffs will not work with their process.
U.S. Pat. No. 5,330,541 to Hall, David M.; Leonard, Tony M.; Cofield, Charles D.; Barrow, Hugh W. (Jul. 19, 1994)
As for the Dyeing time according to Hall et al. in the Prior Art U.S. Pat. No. 5,330,541 the average dyeing time of fiber reactive dyes is between 3 to 6 hours, and that with his process he can reduce the dyeing time from about {fraction (21/2)} to about 3 hours, and to this time you have to add the preparation of the material time plus the conditioning of the material time which add up to an additional {fraction (31/2)} to 4 hours, which at best will be 6 hours. Another disadvantage of the process of the Prior Art U.S. Pat No. 5,330,541 is that 5 water baths are required just for the preparation and conditioning of the cellulosic materials.
U.S. Pat. No. 4,562,604 to Damm, Sture (Jan. 7, 1986)
According to Damm, in the Prior Art U.S. Pat. No. 4,562,204, “if one used dyeing agents and optimum dyeing temperature of the dye bath, containing dyeing agent and electrolyte, adds all necessary alkali initially, one obtains with a great likelihood an uneven dyeing, as the fixation to the fibres is initiated at a high speed and reaches after a few minutes high values. On the other hand one can not reduce the amount of alkali, as it is necessary for attaining the end fixation value at a certain given dyeing time and consequently necessary for the reproducibility of the dyeing. The alkali is added after that the recommended dyeing temperature has been reached. As one can expect a not desired fast start of the fixation, the required amount of alkali must in usual manner be added in portions and at time intervals. These facts are known in several publications, for example in [Le Mustercarte 1350] from Bayer AG”.
Which prove to be true for conventional fiber reactive dyeing processes, but at the same time these procedures are long and time consuming, and to this we have to add the disadvantage of having to spend money on expensive and sophisticated alkali dosing equipment devices like the one that Damm proposes in the Prior Art above mentioned,
U.S. Pat. No. 4,656,846 to Damm, Sture (Apr. 14, 1987) and also on his device proposed in the Prior Art U.S. Pat. No. 4,656,846, where the alkali is dosed in portions by means of an expensive sophisticated electronically programmed controlled dosing device.
U.S. Pat. No. 5,152,802 to Berger, Faize; Becker, Klaus; Hartschen, Christa; Wahle, Bernd; Schenker, Gilbert; Baehr, Bemd-Dieter (Oct. 6, 1992)
According to Berger et al. in the Prior Art U.S. Pat. No. 5,152,802, dyeing with fiber reactive dyes is performed simultaneously with a 4 component anionic and non-ionic surfactant composition without a pre-scouring operation, thus saving time in the process, but unfortunately good level dyeings are difficult to obtain even if the dyestuff formulation comprises just one dye, as can be seen in example 2, table 2 in the Prior Art U.S. Pat. No. 5,152,802 where dyeing levelness is assessed by them a 2-3 rating (1=very good, 6=very bad) on a 2% Levafix Brilliant Blue E-BRA dyeing, leaving one to wonder what kind of ratings could be obtained with 2 and 3 dyestuff formulae combinations. Besides, Berger et al. make no mention whatsoever as for the dyeing time employed in the dyeing process of their invention.
U.S. Pat. No. 4,976,743 to Ohba, Noriaki; Tabata, Yujin; Nagatsuka, Masaaki; Nagatomi, Tateyuki; Klicker, Helmut (Dec. 11, 1990)
In the Prior Art U.S. Pat. No. 4,976,743 (Ohba et al.) describes a leveling agent composition for the treatment of cellulosic fibers that results in improved dyeability with reactive dyes without the need of dosing of alkali or electrolyte, but no mention is made about complete process time, preparation or pre-scouring and after-scouring mode or time, nor amount of water used throughout the entire process, although the 18 comparative examples demonstrated by Orba et al. were runned using a very high 20:1 liquor to fabric ratio.
U.S. Pat. No. 5,015,262 to Ohba, Noriaki; Tabata, Yujin; Nagatomi, Tateyuki (14/0511991)
In the Prior Art U.S. Pat. No. 5,015,262, again Ohba et al. propose a dye leveling agent, based on phospholipid type-compounds, whereby no dosing of alkali is needed, making the process shorter, thus saving time, but according to their invention, hot reactive dyes can not be dyed by their procedure, since the dyeing curves they propose are performed either isothermally at 50° C. as shown in FIG. 1, or at 60° C. as shown on FIG. 2, which is a limitation to their process; also, both dyeing curves take 130 minutes, to which you have to add pre-scouring time plus after-scouring time. Besides, all their experiments are runned with a single dyestuff leading one to wonder what the results would be if 2 or 3 dyestuff combination formulas are used. Again, all tests were performed using a very high 20:1 liquor to goods ratio.
U.S. Pat. No. 4,515,596 to Berendt, Hans-Ulrich; Pacher, Marielise (May 7, 1985)
According to Berendt et al, on The Prior Art U.S. Pat. No. 4,515,596 the scour/bleach operation is performed simultaneously in the after-scouring step, thus dyeing is done on the grey materials, in such a way that the scouring time is saved, but among the many problems we encounter with this process are: (a) only works with a limited combination of fiber reactive dyes; (b) works only with light shades and one dye color formulations as demonstrated on all the examples given; (c) the exhaustion dyeings were all performed using a 40:1 liquor ratio which is highly uneconomical considering that 20% hydrogen peroxide has to be used for bleaching; (d) does not favor the environment; and (e) natural fibers vary in dyeability depending not only on their kind and locality but also on their chemical pretreatment such as scouring and bleaching, it is therefor necessary to establish the proper scouring conditions for the dyeing steps to be able to get good reproducibility and uniform dyeings.
The American Cotton Handbook, volume two, page 760 states that the amount of water needed to process one pound of cotton will run anywhere from forty to seventy gallons, while with this novel process of the present invention the amount of water needed will be about 6 to 7 gallons per pound of cotton processed, that is to say only about 10% of the water required according to the American Cotton Handbook.
In general, the five, and six bath process according to teachings of the present invention is neither taught nor suggested by the known prior art.
OBJECTS AND ADVANTAGES
The five, and six bath process according to teachings of the present invention is neither taught nor suggested by the known prior art, and accordingly several objects and advantages of the present invention are to provide a method for increasing the rate of production of fiber reactive dyed cellulose containing materials per dyeing machine by as much as 60%, to decrease costs of production and save in energy and water consumption.
Other objects and advantages of the present invention are to provide a process which will enable us to obtain outstanding lot-to-lot color reproduction and a reduced hydrolysis dyeing mechanism resulting in more fiber reactive dye being bonded to the substrate thus better color yield.
Still another object and advantage of my invention is to provide tremendous savings in water consumption with positive effects on the environment, where as much as 50% reduction in water consumption and effluents by virtue of the novel process of the present invention are achieved.
Yet another object and advantage of the present invention is to provide a water, energy, and time saving and efficient process for dyeing cellulosic containing materials that is suitable for all types of fiber reactive dyestuffs.
Additional objects and advantages are a reduced process cycle time with an easy-to-use method and to do so in a manner that has ecological benefits.
In utilizing the conventional fiber reactive dyeing process, not only is the dyeing operation expensive and time consuming, but the process is particularly energy intensive, With different baths, sometimes as many as 12 or 14, substantial energy is expended for raising the bath temperature from ambient to elevated temperature conditions at several intervals during the process. Moreover considerable rework is necessary due to shade variability and unlevel dyeings due to strike rate and hydrolysis of reactive dyes and unnecessary dyestuffs and chemicals are therefore wasted in larger amounts; and the protracted length of time required to complete the dyeing reduces the production capacity of the dyeing equipment.
It can be seen from the conventional dyeing processes that just on the after-scouring operation 6 or 7 liquor baths are used, and also that the temperature is raised a combined total of 255° C., which more than triple's the energy consumption of the after-scour process of the present invention. If we consider that for the scouring and preparation of the materials to be dyed, the normal average for conventional fiber reactive dyeing methods requires 5 liquor baths, plus an average of 6 liquor baths for the after-scouring, plus the dyeing bath and the neutralizing bath we have a total of 13 liquor baths against only 5 or at the most 6 of the present invention.
In dyeing cellulose containing materials according to teachings of the present invention, a significantly shorter dye cycle from scour through after-scour is realized, whereby significantly less energy is required for the overall process, and whereby less labor is utilized per pound of goods processed; with the use of the dyeing process of the present invention any color can be dyed from scour through after-scour in less than 5 hours and using only from 5 to 6 liquor baths. Such of course reduces the overall cost of the dyeing operation, raises the dye capacity of the production equipment, and utilizes considerably less water per pound of goods dyed. Furthermore, better dye yields and very level dyeings are obtained by virtue of the present process. Additionally, and very importantly, the tremendous and positively ecological and environmental benefits caused by the reduction of almost 50% in water consumption and effluents by virtue of the present process.
Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying examples.
SUMMARY
It is an object of the present invention to provide a water saving process for dyeing cellulosic containing materials with fiber reactive dyes.
It is another object of the present invention to provide an energy saving process for dyeing cellulosic containing materials with fiber reactive dyes.
Still further, another object of the present invention is to provide a time saving process for dyeing cellulosic containing materials with fiber reactive dyes.
Yet another object of the present invention is to provide a water, energy, and time saving and efficient process for dyeing cellulosic containing materials that is suitable for all types of fiber reactive dyestuffs.
And finally another object of the present invention is to provide perfect even dyeings without the need of dosification of the dyestuffs, the electrolyte, or the alkali into the dye bath, and furthermore perform the dyeing and the soaping in the presence of glacial acetic acid.
Generally speaking, the dyeing process for cellulosic containing materials according to teachings of the present invention includes the steps of scouring the textile material to render same suitable for dyeing without rinsing, while avoiding residual materials that will interfere with dyeing; souring the material in the dye bath with a suitable acid whereby alkali from the scour operation is neutralized and the material is rendered slightly acidic, and adding a dye assist system which reduces hydrolysis of the dyes and is stable to high alkali and high electrolyte content; adding a predetermined fiber reactive dyestuff formulation to the dye bath to achieve a desired shade; adding from about 5 to about 200 grams per liter of electrolyte to the dye bath to permit proper exhaustion of the dyestuff; raising the dye bath temperature to the required dyestuff formulation dyeing temperature; adding appropriate quantity of stable buffered alkali that permits proper fixation and a bath pH of from about 8 to about 12.5, subjecting the material to the dye bath at a predetermined time-temperature relationship to dye said material to said desired shade; and finally rinsing, after-scouring with glacial acetic acid and soaping agent, and rinsing said material.
In dyeing cellulose containing materials according to teachings of the present invention, a significantly shorter dye cycle from pre-scour through after-scour is realized, whereby significantly less energy is required for the overall process, and whereby less labor is utilized per pound of goods processed; with the use of the dyeing process of the present invention any color can be dyed from pre-scour through after-scour in less than 5 hours and using only from 5 to 6 liquor baths. Such of course reduces the overall cost of the dyeing operation, raises the dye capacity of the production equipment, and utilizes considerably less water per pound of goods dyed. Furthermore, better dye yields and very level dyeings are obtained by virtue of the present process. Additionally, and very importantly, the tremendous and positively ecological and environmental benefits caused by the reduction of almost 50% in water consumption and effluents by virtue of the present process.
The novel process of the present invention is a challenge to state of the art fiber reactive dyeing procedures, is as if it was designed to “defeat the purpose” in every important step of the process per se, anyone skilled in the art would expect obviously disastrous results as the logical outcome; no rinsing after the scouring operation, dyeing reactive dyes in the presence of glacial acetic acid, no dosing of dyes, no dosing of electrolyte, no dosing of alkali, soaping with glacial acetic acid; what else can you expect but faulty dyeings with such a process?. Surprisingly the results are absolutely the opposite, we get perfectly even dyeings, even the most difficult colors, like the greens, camels, beige's and grays, and even deep royals with reactive blue C.l.# 19 come out even and in less than 5 hours complete process time.
BRIEF DESCRIPTION OF THE INVENTION
In general the process of the present invention is directed to dyeing operations in which fiber reactive dyestuffs are employed to dye cellulosic containing materials such as cotton and rayon. The cellulosic component may be represented by fiber, yam, woven, knitted, nonwoven or other structure. The present invention relates to a process for dyeing with reactive dyes on cellulose substrates, starting with the raw substrate and ending up with the ready to be finished substrate in a time of 5 hours or less and requiring from 5 to 6 liquor baths only.
It is of common knowledge to all skilled in the art, that the complete process of dyeing cellulose fabrics with fiber reactive dyes starting from the raw takes at least in the best of cases 7 hours, and it is well known than in common practice a very good average time is 8 hours.
The present invention takes at the most 5 hours, which in a 24 hour time period we get 5 dye lots out of 1 dyeing machine against 3 conventionally dyed dye lots out of 1 dyeing machine in the same 24 hour period. That is two-thirds increase in production, which will definitely cause quite a positive impact in the art.
The present invention does not contemplate just the dyeing part of the process, it contemplates the dyeing system as a whole, in other words the scouring and preparation of the goods to be in optimum conditions to be dyed, the dyeing of the goods in such a way that very little hydrolyzed dye is left over for the third stage of the process to be fast and effective, which is the after-scouring or soaping stage, the removal of the dyestuffs that did not get fixed on the substrate during the dyeing stage.
Materials to be dyed according to the present process are scoured for 5 to 15 minutes at 95° C. to 110° C. to remove wax, dirt, knitting emulsions and other materials to generally clean the material while avoiding the use of chemical systems that will leave residual components which could retard the dyeing. Thereafter, the scoured material is cooled by overflow to about 40° C., and without any further rinse, acid souring and dyeing are performed in the following bath.
Insofar as the dye bath is concerned, a low liquor volume is preferred, preferably in a liquor to material weight ratio range of about 15 to from about 20 to one for beck dyeing and for jet dyeing from about 5 to about 10 to one. In case that the scoured material was simultaneously bleached, care should be taken as not to have any hydrogen peroxide residues present in the dye bath. Once the bath is free of peroxide, bath temperature is adjusted, if necessary, to a range of from about 20° C. to about 40° C.
The order of addition of chemicals and dyestuffs is critical. First, the acetic acid is introduced into the dye bath. Second, the dyeing assist agent is introduced. Third, the dyestuffs are introduced in the dye bath, and fourth the electrolyte is introduced to the dye bath, this 4 components introduced at the initiation temperature of about 20 to about 40° C. Thereafter the dye bath temperature is raised to the desired dyeing temperature in a time period of about 10 to 20 minutes for 60° C. dyeings and about 15 to 30 minutes for 80° C. dyeings. Ten minutes after the desired dyeing temperature is reached, the alkali is introduced in the dye bath in one portion and dyeing is carried on for a further 20 to 60 minutes.
Subsequent to dyeing, the materials are cold water rinsed, soaped in the presence of acetic acid and soaping agent, hot water rinsed, and cold water rinsed for dark and very dark shades;
Cold water rinsed, soaped in the presence of acetic acid and soaping agent, and cold water rinsed for medium shades; and
Soaped in the presence of acetic acid and soaping agent and cold water rinsed for light and pastel shades.
Afterwhich the then dyed materials are further processed as intended.
In dyeing cellulose containing materials according to teachings of the present invention, a significantly shorter dye cycle from scour through after-scour is realized, whereby significantly less energy is required for the overall process, and whereby less labor is utilized per pound of goods processed; with the use of the dyeing process of the present invention any color can be dyed from scour through after-scour in less than 5 hours and using only from 5 to 6 liquor baths. Such of course reduces the overall cost of the dyeing operation, raises the dye capacity of the production equipment, and utilizes considerably less energy and water per pound of goods dyed. Furthermore, better dye yields and very level dyeings are obtained by virtue of the present process. Additionally, and very importantly, the tremendous and positive ecological and environmental benefits caused by the reduction of almost 50% in water consumption and effluents by virtue of the present process.
THEORY OF OPERATION—DESCRIPTION
The scouring operation is fast and effective because of the auxiliary components and the synergy between them:
The surfactant has as its main ingredient about 40% of a 13 mole nonyl phenol ethoxylate, which is effective at boiling temperatures since it has a high cloud point as compared to 9 and 10 mole nonyl phenol ethoxylates which have a cloud point of 52° C. and 60° C. respectively, and above those temperatures they act against instead of for the purpose of cleaning. The disadvantage of 13 moles is that its more difficult to rinse-off the fabrics, but that problem is overcomed by the dispersability and sequestering properties of the polyacrylates that are present in the surfactant.
In addition, the presence of about 6.5% Toluol perfectly emulsified in the surfactant plus the presence of Tween.RTM. and Span.RTM. on the surfactant formulation make it possible for having any cellulosic containing material in optimum conditions to be dyed in a scouring time of 5 to 15 minutes at the boil.
The other product that goes in the pre-scour is a stable buffered alkali, which is much more easier to rinse-off the fabric than caustic soda or soda ash, which are used on cellulose scouring 99.9% of the time.
The combination of both products makes it possible to start the dyeing operation in the next bath, just by cooling with overflow is sufficient to get rid of all the waxes, dirt, oils, soil, grease, surfactant, and alkali.
The inventor in plant trials has proved this theory to work whereby in 40 minutes and one water bath only the goods were in optimum condition to be dyed.
As for the dyeing the operation, its started immediately after the sole scour bath is dropped, with the addition of glacial acetic acid, which not only serves as the pH bath neutralizer, while I also believe it serves as the compatibilyzer between the sodium-meta nitrobenzenesulphonate and the sodium polyacrylate, I don't wish to be bound by this; which serve as the leveling and anti-hydrolyzing system of the dyeing operation of the present process. Sodium polyacrylate is not compatible with oxidizing agents, and sodium-meta nitrobenzenesulfonate is an oxidizing agent used to prevent the reduction of the fiber reactive dyes and thus hydrolysis. The presence of the glacial acetic acid also prevents hydrolysis of the fiber reactive dyes, it is known, for example, that dyeings from dyes of the vinyl sulphone type are resistant to acid hydrolysis, the ether being more stable to the glucoside linkage in cellulose; the link with cellulose is, however, susceptible to alkaline hydrolysis when the vinyl sulphone is reformed.
It is because of the combination of the 3 products above mentioned that the dyestuffs are added to the dye bath in one portion in a time period of from 5 to 10 minutes, without the need of long dosing in portions as is done in conventional dyeing processes, and in the same manner, the electrolyte is added to the dye bath in a 5 to 10 minute period instead of the 20 to 30 minutes as done conventionally.
The reason why the alkali is not added at this point or before the addition of the electrolyte, but instead the temperature is raised to 60° C. or 80° C. and a 10 minute period holding time at the dyeing temperature is taken before the addition of the alkali takes place, is because from liquor ratios of 5:1 and above, it is advantageous to transfer the maximum amount of dye to the fibre prior to alkali addition by addition of electrolyte. By so doing, a substantial quantity of dye may be sorbed under neutral conditions and hence be applied in a level fashion; and also, in the 30 or 40 minute time period from the addition of the electrolyte to the addition of the alkali, about 70% of the reactive dyes are sorbed, leaving about 30% of the dyes in the dye bath to compete with OH (−) and the CellO (−).
The alkali is added to the dye bath in a time period of 5 to 10 minutes, without the need of dosing in portions or spending money in costly dosing equipment, because the stable buffered alkali used in the process of the present invention has the ability to maintain the pH constant during the process, with variations of less than 0.1 in pH over a 50 minute dyeing time period, therefore loosing time in programmed dosing is absolutely not necessary, sudden strike rates of dyestuffs are avoided since the pH is maintained constant, better reproducibility is obtained and less dyestuff is hydrolyzed by avoiding [high alkali-high temperature-long time] exposure, making the next step of the process, the after-scouring or soaping step, much faster and simpler since the amount of hydrolyzed dye has been minimized and controlled all through the dyeing process.
As for the after-scouring, acetic acid is used simultaneously with the soaping agent, thus no neutralizing bath is required between the dye bath and the soaping bath; the soaping agent is made of about an 18,000 to 24,000 molecular weight polyacrylate which is capable of sequestering the hydrolyzed dyestuffs and prevents their redeposition on the substrate, thus 99.9% of the time one soaping bath is sufficient to get excellent washfastness properties from the dyed substrate.
It is the above mentioned combination of features and dyeing chemical auxiliaries that permits the reactive dyeing process of the present invention to perfectly work in less than 5 hours and requires at the most 6 water baths.
As for the dyeing chemical auxiliaries, the scouring agent, Texdet SS, has the unique feature of being able to optimally prepare the substrate for dyeing in just 5 to 15 minutes, which is a novelty to the prior art. As for the dyeing assist agent, Antydrol A, its components are known to the prior art as separate individual components for different applications and not as a leveling anti-hydrolyzing agent product per se. In regards to the soaping agent, Texsoap FT, the sodium polyacrylate˜20,000 MW is not known to the prior art as being used as a soaping agent. Moreover, as for the stable buffered alkali, Alkatex F, many similar products are known in the prior art, but none with the feature of maintaining a pH value with a variation of less than 0.1 throughout the entire dyeing process.
The above mentioned dyeing chemical auxiliaries that complement the success of dyeing process of the present invention are formulated as follows: All formulations are given in parts by weight.
Texdet SS
Nonyl Phenol - 13 moles EO (40%)
82.6
18.3
Nonyl Phenol - 10 moles EO
—
16
Nonyl Phenol - 30 moles EO (35%)
—
45.04
Tween.RTM. 80
0.72
0.56
Span.RTM. 80
0.03
0.022
Toluol
6.65
5.1
Sodium Polyacrylate MW 5,000
10
14.978
Antydrol A
Sodium-meta Nitrobenzenesulfonate (20%)
79.7
71.58
Sodium Polyacrylate MW 5,000
20
28
Glacial acetic acid
0.3
0.42
Texsoap FT
Sodium Polyacrylate MW 20,000 (40%)
80
50
Water
20
50
Alkatex F
Sodium Hydroxide (50%)
30
30
—
Potasium Hydroxyde (55%)
32
32
25
Potasium Carbonate (48%)
—
—
63
Phosphoric acid (20%)
30
38
—
EDTA
3
—
5
Sodium Polyacrylate MW 3,000
5
—
3
Phosphoric Acid (50%)
—
—
4
DETAILED DESCRIPTION OF THE INVENTION
Since non-of the process stages is conventional, all the ingredients and conditions for these stages are critical and highly preferred. As such, each of the general process steps will be described with specific detail, alluding as to each, any criteria that could adversely affect the dyeing operation, or that is preferred or critical.
Scouring: Specifics of the scour operation are dictated by the color shade that is desired, and mainly there are two basic operating methods:
a) Medium, dark, and very dark shades, and
b) Light or pastel shades.
First of all it should be taken into account that all through the process of scouring, dyeing, and after-scouring the material must be running at the fastest permissible travelling speed through the bath liquor, and if necessary an antifoaming agent and a dye bath lubricant could be used in the scouring and in the dyeing operations, no other chemicals should be added unless specified.
a) For Medium, Dark and Very Dark Shades the Scouring is Carried Out in the Following Manner:
Once the dyeing machine is loaded with the material and material is running, open the steam valve completely and add to th e scour bath through the chemical feeding tank from about 0.8 to about 1.5 grams per liter of Texdet SS, a non-ionic blend of adducts of ethylene oxide, sorbitols, polyacrylates, and solvents; once the product is in the bath, add from about 0.5 to about 2 cc/l (cubic centimeter per liter) of Alkatex F, a stable buffered alkali which is a blend of alkali metal hydroxides, alkali metal carbonates, and phosphoric acid, diluted with plenty of water and feed it through the feeding tank in a time period of about 1 minute, keep in mind that steam valve should be completely open until we reach a temperature of from about 95° C. to about 110° C. The scour bath should be held for about 5 to 8 minutes at 110° C. and about 10 to at the most 15 minutes at the boil, afterwhich the scour bath is cooled to about 80° C. and the overflow valve is open until a temperature of about 40° C. is reached and the scour bath is dropped. No further rinse is necessary; we go directly to the dyeing bath right after this scouring procedure. The scour operation of the dyeing process of the present invention should take about 40 to 50 minutes and requires only one water bath.
b) For Light or Pastel Shades the Procedure is as Follows:
Adding about 0.8 to 1.5 g/l Texdet SS, increasing the amount of Alkatex F to from about 0.5 to about 2 cc/l, and adding anywhere from about 1 to about 5 grams per liter of hydrogen peroxide (50%), the amount of peroxide determined by the degree of whiteness that is required to be achieved, and if desired a non-silicate peroxide stabilizing agent could be added to the bath; once boiling temperature is achieved the scouring/bleach bath is kept at boiling temperature for 30 minutes, or could be held for about 15 minutes at 110° C.; then cooled indirectly to 80° C., and then cooled by overflow to about 35° C. and the bath is dropped. Now we proceed with a 5 to 10 minute hot water rinse (from 50° C. to about 80° C.), cooling then by overflow to 35° C., dropping the bath and we are now ready to proceed with the dyeing operation of the process. The scouring/bleach operation of the dyeing process of the invention should take about 80 to 90 minutes and requires two water baths.
For the dyeing operation of the process of the present invention we proceed as follows: The vat is filled with a low water level, taking into account the volume needed for the dyeing assist agent, the dyestuffs, the electrolyte and the alkali, thereafter from about 0.1 to about 0.2 g/l of glacial acetic acid is added to the dye bath through the feeding tank diluted with water, the goods are runned for about 3 minutes and anywhere from 2 to about 5% of Antydrol A, an anti-hydrolysis leveling assist, which is a blend of low foaming sulfonated oxidizing agents and polyacrylates, is added to the dye bath and after 5 minutes the dissolved reactive dyes are added to the dye bath through the feed tank in a time period of 5 minutes for dark, and very dark shades and 10 minutes for medium, light and pastel shades; once the dissolved reactive dyes are in the dye bath the goods are left running for 5 minutes for dark and very dark shades and 10 minutes for medium, light, and pastel shades; and now we proceed with the electrolyte addition which again should be fed into the dye bath in a period of 5 minutes for dark and very dark shades and 10 minutes for medium, light, and pastel shades, thereafter heating the dye bath to the desired dyeing temperature at a rate of about 1.5 to 3° C./minute; then 10 minutes after arriving to the dyeing temperature anywhere from 1.5 to about 6 cc/l of Alkatex F diluted at least 1:10 in water is added to the dye bath through the feed tank, making sure that the feed tank is full of dye bath liquor, and fed in a time period of 7 to 10 minutes, thereafter holding at the dyeing temperature for about 20 to 40 minutes for medium, light, and pastel shades and for about 45 to 60 minutes for dark and very dark shades, after which sample is checked for shade and the dye bath cooled by overflow to 40° or 35° C. and dropped. This Dyeing part of the dyeing process of the invention should take about 115 to 120 minutes and requires only one water bath.
The after-scouring operation of the dyeing process of the present invention is carried out as follows:
For light and pastel shades we load the vat with water and add from about 0.2 to about 0.4 g/l glacial acetic acid through the feed tank and diluted with plenty water, and after a time period of 3 minutes we open the steam valve completely and add from about 0.5 to about 1% by weight of the dry material of Texsoap FT, which is a low foaming soaping agent made out of polyacrylates with a molecular weight of about 18,000 to about 24,000, the bath temperature is raised to from about 70° C. to about 85° C., and after 5 to 10 minutes the bath is cooled by overflow to about 35° C. and the bath is dropped. Thereafter the material is subjected to a 5-minute cold water rinse and unloaded without dropping the rinse bath, which is used to pre-scour the next dye load.
For dark and very dark shades, the material is subjected to a 5-to 10 minute cold water rinse and the bath is dropped. Thereafter in a new bath we add from about 0.2 to about 0.4 g/l glacial acetic acid and after 3 minutes the steam valve is opened completely and from about 0.5 to about 1.5% of Texsoap FT is added to the after-scour bath then taken anywhere to from 80° C. to 105° C. and held at such temperature for from about 5 to about 20 minutes, thereafter the bath is cooled indirectly to 80° C., the overflow valve is opened and the bath cooled to about 40° C.and the bath is dropped. The material is then subjected to a hot water 5 to 10 minute rinse at a temperature of from about 60° C. to about 80° C. afterwhich the overflow valve is opened and the bath cooled to about 40° C. and the bath is dropped. Finally the material is subjected to a 5-minute cold water rinse and the goods are unloaded without dropping the final rinse bath, which will be used for the next dye load. For medium shades the hot water rinse is obviated. The after-scouring of light and pastel shades of the dyeing process of the present invention requires about 40 to 45 minutes and only 2 water baths, about 60 minutes and 3 water baths for medium shades, while dark and very dark shades require about 90 minutes and 4 water baths. It should always be observed that when the rinse and soaping baths are dropped, enough time should be given for the bath liquors to drain from the fabric.
The overall process time of the present invention is about 250 minutes for light and pastel shades, 260 minutes for medium shades, and about 280 minutes for dark and very dark shades, and the water consumption is 5 water baths for medium, light and pastel shades and 6 for dark and very dark shades.
The dyeing process of the present invention is a challenge to state of the art techniques, is as if it was designed to “defeat the purpose” in every important step of the process per se, anyone skilled in the art would expect obviously disastrous results as the logical outcome; no rinsing after the pre-scouring operation, dyeing reactive dyes in the presence of glacial acetic acid, no dosing of dyes, no dosing of electrolyte, no dosing of alkali, soaping with glacial acetic acid; what else can you expect but faulty dyeings with such a process?. Surprisingly the results are absolutely the opposite, we get perfectly even dyeings, even the most difficult colors, like the greens, camels, beige's and grays, and even deep royals with reactive blue C.l.# 19 come out even and in less than 5 hours complete process time.
The use, advantages, and benefits of the fiber reactive dyeing process of the present invention comprising the methods of scouring, dyeing, and after-scouring cellulose containing materials, will now be described in more detail by reference to the following specific, non-limiting Examples:
EXAMPLE 1
140 Kgs of a 24 single's 24 cut cotton jersey knit are to be dyed deep royal on an atmospheric winch dyeing machine with a liquor to fabric ratio of 20:1, 7-20 Kg pieces taking 1.5 minutes per turn.
For the scouring operation the following products were used:
1 g/l Texdet SS
1 g/l Texiube SN
0.8 cc/l Alkatex F
First, the surfactant and the dye bath lubricant were added, the steam valve opened completely, and then the alkali was added, the scour bath reached the boiling point in 12 minutes and the temperature was held for 10 minutes and the bath cooled in 10 minutes to 80° C., thereafter cooled by overflow to 40° C. and the bath was dropped.
The dyeing was performed in the next bath as follows:
0.12 g/l glacial acetic acid
4% Antydrol A
2.75% Cibacron.RTM. Blue FG-FN (Ciba Colors)
0.75% Cibacron.RTM. Red FB
60 g/l Sodium Sulphate
2 g/l Alkatex F
In the next bath 2400 lt. liquor were added and the goods were soured with glacial acetic acid, and 5 minutes later, the Antydrol A was added, and 10 minutes later the dyestuffs which had been dissolved in 150 liters water were added in a 10 minute period. 10 minutes later, 168 kgs of sodium sulphate were added over a 10 minute period, and after 10 minutes the dye bath temperature was raised to 60° C. in a time period of 20 minutes, and the temperature was held for 10 minutes, afterwhich 5.6 liters of Alkatex F dissolved in 100 liters water were added over a 10 minute time period, thereafter dyeing was continued at 60° C. for 50 minutes, and the goods were cooled to 40° C. by overflow.
The after-scouring operation was performed as follows:
a) a 10-minute cold water rinse;
b) the vat was filled with 2800 lt. of water, and 0.3 g/l glacial acetic acid was added, and then the steam valve was completely opened, and 3 minutes later 1.5% Texsoap FT were added, the bath temperature was taken to 90° C. in 10 minutes, and was held thereafter for a further 10 minutes, afterwhich it was cooled to 80° C. in 5 minutes, and then cooled to 40° C. by overflow;
c) a 5 minute hot 70° C. water rinse, and finally
d) a 10-minute cold water rinse, the goods were unloaded without dropping the bath, which is subsequently used to pre-scour the next dye lot.
After drying and finishing the fabric was perfectly level and the washfastness and light fastness were excellent.
EXAMPLE 2
180 Kgs. of a 30 single's Tanguis cotton 28 cut jersey knit were loaded on an overflow ATYC dye machine, and dyed to a navy blue color in a 1,200 liter total bath (liquor ratio 6,7 to 1). The fabric speed was set at 240 meters/minute, scoured at the boil for 10 minutes with 1.2 g/l Texdet SS, 0.9 cc/l Alkatex F, 1 g/l Texlube SN, a monostearate dye bath lubricant manufactured by Tex-Chem Inc. of Coral Gables, Fla., and 0.2 g/l Foamaster.RTM. 340 antifoam from Rhone-Poulanc Co., the bath indirectly cooled to 80° C., and then cooled to 40° C. by overflow. The bath was dropped and in the next bath water was filled to the 950 liter level mark, the bath temperature was 30° C., and 0.13 g/l (based on 1200 liters) glacial acetic acid diluted in the dye bath liquor were introduced through the chemical feed tank, and after 3 minutes a sample of scoured fabric was taken to check pH and wettability, the fabric at this point had a pH of 6.7 and had outstanding wettability, then 3% of Antydrol A were introduced to the dye bath, and 5 minutes later the dyestuffs of the following formulation was introduced in a time period of 7 minutes, dissolved in 100 liters of water:
2.62% Remazol.RTM. Black BB (DyStar)
0.74% Remazol.RTM. Golden Yellow 3R
0.40% Remazol.RTM. Brilliant Red F3B
After 5 minutes, 70 g/l (based on 1200 liters) of sodium chloride were added to the dye bath in a 5 minute time period. The fabric was held running through the dye liquor for 5 minutes, and the dye bath temperature was raised to 60° C. in a time period of 20 minutes, and held at 60° C. for a further 10 minutes and then 4 cc/l of Alkatex F dissolved in 60 liters of water were introduced to the feed tank which had 100 liters of dye liquor in it, and were introduced in the dye bath in a 7 minute time period, the temperature was held for a further 45 minutes at 60° C., the dye bath cooled by overflow to 35° C. and then dropped. The fabric was then subjected to a 5 minute cold water rinse, the bath dropped and then in a 1800 liter new bath 0.4 g/l glacial acetic acid were introduced and steam valve fully opened, after 3 minutes 1.2% Texsoap FT was introduced and the bath taken to 95° C. in a 10 minute period and held at that temperature for 15 minutes, afterwhich the bath was indirectly cooled to 80° C., and then cooled by overflow to 40° C. and dropped. Then the fabric was subjected to a 5 minute rinse at 70° C., cooled by overflow to 35° C. and the bath dropped, and finally subjected to a 10 minute cold water rinse and the fabric unloaded without dropping the bath which could be used for the scouring of the next dye-lot. The results obtained for the dyed fabric of Example 2 were a deep navy blue color with outstanding leveling and very good wash fastness and light fastness properties. Furthermore, pH dye bath measurements were taken during dyeing at 5, 20 and 40 minutes after the alkali was introduced and the readings showed pH values of 10.8, 10.78, and 10.72 respectively.
EXAMPLE 3
150 Kgs of a 40/2 28 cut interlock Pima cotton knit fabric were loaded in a Scholl overflow jet dyeing machine, with 1,200 lt. of water, liquor to fabric ratio of 8 to 1 and a Royal Blue was dyed in the following manner: Scouring for 15 minutes at the boil with:
1.5 g/l Texdet SS
1.1 cc/l AlkatexF
1.2 g/l Texlube SN
0.2 g/l Foamaster.RTM. 340 (Rhône-Poulenc)
The reason why we increase the amounts of surfactant and alkali is that Pima cotton needs a stronger pre-treatment than Tangüis cotton. The dyeing operation is carried out as follows:
0.15 g/l Glacial acetic acid
4% Antydrol A
4% Remazol.RTM. Brilliant Blue R Special (DyStar)
60 g/l Sodium Sulfate
3.0 cc/l Alkatex F
The dyeing was carried out at 60° C. the same way as example 2 but the dyeing time was 50 minutes after the addition of the alkali. The soaping operation was carried as in example 2. The results obtained for example 3 were a very level dyed Royal Blue with excellent wash and lightfastness.
EXAMPLE 4
150 Kgs of a 30 single's 28 cut cotton jersey knit fabric are to be dyed Olive Green in 1,500 lt., dye liquor ratio 1:10 in a Scholl jet dyeing machine. The scouring procedure was performed exactly as example 2; the fabric is dyed in the following manner:
0.13 g/l glacial acetic acid
3% Antydrol A
1.20% PROCION.RTM. Yellow HE4R (Zeneca colors)
0.46% PROCION.RTM. Red HE-3B
1.15% PROCION.RTM. Green HE4BD, and after 5 minutes
90 g/l Sodium Sulfate; all this products are added following the same sequence as Example 2, 5 minutes after the addition of the electrolyte, the dye bath temperature is raised to 80° C. in a time period of 30 minutes, and 10 minutes later 4 cc/l of Alkatex are added over a 10 minute period, afterwhich the dyeing is carried out for a further 45 minutes
The after-scouring operation is performed as Example 2. A very level dyed olive green fabric is obtained with excellent fastness to washing and light.
EXAMPLE 5
150 Kgs of a 20 single's 24 cut cotton knit fabric to be dyed deep blue are loaded in a AKM overflow dyeing machine in a 10:1 liquor ratio. The scouring operation is carried in the same manner as with example 2; thereafter the dyeing operation is carried out with the following products:
0.13 g/l glacial acetic acid
3% Antydrol A
3% CIBACRON.RTM. Blue FGFN, are added in 5 minutes, and after
10 minutes
80 g/l Sodium Sulfate are added in a 5 minute time period; and 10 minutes later the temperature was raised to 60° C. in a 20 minute time period, and 10 minutes later 3 cc/l of Alkatex F, over a 10 minute time period were added, afterwhich dyeing was carried for a further 50 minutes. The soaping operation was carried as in Example 2
A deep blue dyeing with excellent leveling and fastness to light and washing was obtained.
EXAMPLE 6
180 Kgs of a 30 single's 28 cut jersey knit cotton fabric are to be dyed Kelly Green in a 1500 lt. bath, liquor ratio 8:1, in an overflow ATYC dyeing machine. The fabric is scoured at the boil for 15 minutes, using same procedure as in example 3. The dyeing is carried out as follows:
0.15 g/l glacial acetic acid
4% Antydrol A
4.06% REMAZOL.RTM. Turquoise RP (DyStar)
1.1% REMAZOL.RTM. Brilliant Yellow 4GL, added in 7 minutes, and 10 minutes later
70 g/l Sodium Sulfate were added in 7 minutes, after 10 minutes the temperature was raised to 80° C., and held for 10 minutes and 5 cc/l Alkatex F were added over a 10 minute time period, afterwhich the bath was held at 80° C. for a further 50 minutes. The after-scouring operation was done as follows:
a) a 5-minute cold water rinse;
b) soaped at 95° C. with 0.4 g/l glacial acetic acid and 1.5% Texsoap FT for 15 minutes;
c) a 5 minute 70° C. hot water rinse;
d) 5 minute cold water rinse & unloaded.
The results obtained were a perfectly even dyed Kelly green with excellent fastness to washing and light.
EXAMPLE 7
150 Kgs of a 24 singles double-piqué cotton fabric are loaded in a Scholl overflow dyeing machine to be dyed to a light mustard color in a 1,200 liter bath, a liquor to fabric ratio of 8:1; the goods are first scoured/bleached in the following manner:
1.5 g/l Texdet SS
1.5 cc/l Alkatex F
0.1 g/l STABICOL.RTM. A, a peroxide stabilizer from Allied Colloids inc.
0.2 g/l FOAMASTER.RTM. 340 (Rhône-Poulenc)
1.5 g/l Texlube SN
3 g/l Hydrogen Peroxide 50%
the bath temperature was taken to the boil in 12 minutes and held for a further 30 minutes, afterwhich indirectly cooled to 80° C., and then cooled by overflow to 35° C. and dropped; the fabric was given a 5 minute 80° C. hot water rinse and cooled by overflow to 35° C. And dropped. The dyeing was done as follows:
0.1 g/l glacial acetic acid
2% Antydrol A
0.232% Synozol.RTM. Golden Yellow HF-2GR 150% (Kyung ln, China)
0.027% Synozol.RTM. Red HF6BN 150%
0.029% Synozol.RTM. Blue SHF-BRN 150% the dyes were added over a 10-minute time period dissolved in 100 lt. of water, and after 10 minutes 30 g/l Sodium Sulfate were added, over a 10 minute period, and 10 minutes later the temperature was raised to 60° C. in 20 minutes, held for 10 minutes and the addition of 2.2 cc/l of Alkatex F over a 10 minute period, the dyeing was performed for a further 30 minutes, afterwhich cooled by overflow to 30 ° C. and dropped. The bath was filled with 1,500 liters of water, 0.2 g/l glacial acetic acid were added and 3 minutes later 0.8% Texsoap FT were added and the temperature raised to 85° C., and held 10 minutes at 85° C., afterwhich the goods were cooled by overflow to 35° C. and the bath was dropped.
Finally a 5-minute cold water rinse was given and the fabric was unloaded without dropping the bath which served for the scouring of the next dye-lot. A very good level dyed fabric was obtained with excellent fastness to light and washing. Only 5 water baths were employed, or actually 4 if you consider that the last rinse bath is going to be used for the next dye-lot.
EXAMPLE 8
300 Kgs of 30 single's cotton yarn are to bee dyed brown in a Scholl pressure package yam dyeing machine, in a 10 to 1 liquor ratio.
For the scouring, we proceed as follows: Time pressure factor 3.5′ in 4.5′ out.
1.5 g/l Texdet SS
1.1 cc/l Alkatex F
0.3 g/l Foamaster.RTM. 340, taken to 110° C. in 14 minutes, and held at that temperature for 8 minutes, afterwhich the bath was cooled to 40° C. by overflow and dropped. The dyeing was performed in the next bath with:
0.2 g/l Foamaster.RTM. 340
0.14 g/l glacial acetic acid, then, after 8 minutes
3% Antydrol A, then, after 8 minutes
1.3% Synozol.RTM. Golden Yellow HF-2GR 150%
0.7% Synozol.RTM. Red HF-6BN 150%
0.6% Synozol.RTM. Black B 150%, the dyed added in 8 minutes,
and after 8 minutes, 80 g/l sodium chloride are added, in 8 minutes, after 8 minutes the bath temperature was raised to 60° C. in 20 minutes time; 8 minutes later 4 cc/l Alkatex F were added, in an 8 minute time period, thereafter dyeing was carried out for a further 48 minutes, then was cooled to 30° C. by overflow and dropped, and in the next bath the soaping was performed by addition of 0.4 g/l glacial acetic acid and 1.5% Texsoap FT at 104° C. for 16 minutes afterwhich the bath was cooled to 40° C. by overflow and dropped. The yam was then subjected to a hot water 16minute rinse at 80° C., and then cooled by overflow to 40° C. and dropped. The yam was then subjected to an 8 minute cold water rinse, the bath dropped, and finally was subjected to a combined fixing and softening bath at 50° C. for 20 minutes with 0.2 g/l glacial acetic acid, 2.7% Tinofix.RTM. ECO, a diamine-epichlorohydrin blend fixing agent from Ciba, and 3% Texsoft PE, a cationic emulsified polyethylene softener. The yam was unloaded, the complete process took less than 5 hours, required only 6 water baths, fixing and softening included, excellent color leveling through the yam package was observed, a deep bright brown color was obtained which had excellent fastness to light and washing.
CONCLUSIONS, RAMIFICATIONS, AND SCOPE
Accordingly, it can be seen that in general the five, and six bath dyeing process according to teachings of the present invention is neither taught nor suggested by the known prior art; according to the present invention I have provided a method which allows the user to obtain reliable dyeings with all types of fiber reactive dyes, in a much shorter process time, with tremendous savings in water, energy and operation costs, and above all, the tremendous positive impact to the environment caused by the reduction of almost 50% in water consumption and effluents by virtue of the present process.
In utilizing the conventional fiber reactive dyeing process, not only is the dyeing operation expensive and time consuming, but the process is particularly energy intensive. with different baths, sometimes as many as 12 or 14, substantial energy is expended for raising the bath temperature from ambient to elevated temperature conditions at several intervals during the process. Moreover considerable rework is necessary due to shade variability and unlevel dyeings due to strike rate and hydrolysis of reactive dyes and unnecessary dyestuffs and chemicals are therefore wasted in larger amounts; and the protracted length of time required to complete the dyeing reduces the production capacity of the dyeing equipment.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Various other embodiments and ramifications are possible within it's scope. For example, dyestuff additions for shade correction can be done at the dyeing temperature without the need of cooling or dropping part of the dye bath, adding the necessary amount of dyestuff in a 5 to 10 minute period, and the required alkali in the same manner. In addition, the process could be used for dyeing cellulosic containing materials blended with other fibers like nylon, polyester, etc. Besides, unloading the material without dropping the rinse bath and using it for pre-scouring the next dye lot can save extra water. Also, viscose rayon can be dyed with the process of the present invention by making slight changes, i.e. decreasing the amount of alkali and the temperature in the scouring operation, and increasing the amount of dye assist agent in the dyeing operation, etc.
Thus, the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | A process for dyeing cellulosic containing textile materials with fiber reactive dyestuffs whereby from the scouring thru the after-scouring's final rinse less than 5 hours are required and only from 5 to 6 liquor baths are used. Material to be dyed is prepared for dyeing in 10 to 15 minutes at the boil, dyeing is performed in the next bath with no intermediate rinse. Glacial acetic acid, auxiliaries, and dyestuffs are added to the dye bath along with specified amounts of electrolyte, and after the required dyeing temperature is reached specified amounts of alkali are added to the dye bath and the materials subjected thereto at proper time-temperature relationships for level dyeing of a particular shade. Dyestuffs, electrolyte, and alkali are added to the dye bath in one portion with no dosing in a time period of from about 5 to 10 minutes each. The material is neutralized and soaped simultaneously. | 3 |
This is a divisional application of application Ser. No. 07/462,528 filed Jan. 8, 1990 now U.S. Pat, No. 5,171,276.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates broadly to prosthetic implants, and more particularly, to prostheses for human joints, such as the knee, implantable by means of arthroscopic as well as open surgical techniques.
2. Discussion of the Prior Art
Previous proposals for artificial knee prostheses including components for surgical implantation into a patient's knee are known in the art. The complexity of normal knee movement, however, has rendered the attainment of natural knee action quite difficult. More specifically, the natural knee joint includes the bottom part of the femur, constituted by the two condyles, the lower parts of which bear upon the complementary shaped upper surface plateaus of the tibia through the intermediary of cartilage or meniscus. Connection through the knee is provided by means of ligaments which also provide joint stability and assist in absorbing stresses applied to the knee. The femur, cartilage and tibia are normally subjected to significant compression loading in supporting the weight of the body.
Movement of the normal knee is not a true hinged joint about a single center but, rather, is a complex action including rocking, gliding and axial rotation. During the first part of the knee movement from full extension of the leg towards flexion, there is pivotal rotation of the tibia about the femur, which is then converted to a rocking movement wherein the femoral condyles roll posteriorly on the tibial plateaus. The rocking movement then changes to a combined sliding and pivoting movement wherein successive points on the femoral condyles slide forward on the tibial plateaus until full flexion is obtained. In other words, the flexion movement is polycentric, that is, about different centers which are not fixed in one position but lie in a somewhat spiral or polycentric pathway.
A variety of total knee prostheses have been proposed, essentially being of two broad types, hinged and non-hinged. Knee prostheses of the first category possess significant disadvantages in that they generally involve the removal of natural ligaments and only permit motion about a single axis as opposed to the controlled rotation and translation characteristic of a natural, healthy knee.
Knee prostheses of the second type generally include femoral components secured to the condylar surfaces of the femur, typically having cylindrical bearing surfaces, and tibial components fixed to the tibial plateaus, the femoral components bearing against the upper surfaces of corresponding tibial components. Examples of prostheses of the latter type are shown in U.S. Pat. No. 4,470,158 to Pappas et al; U.S. Pat. No. 4,211,228 to Cloutier; U.S. Pat. No. 4,207,627 to Cloutier; and U.S. Pat. No. 3,953,899 to Charnley.
In addition to total knee replacement, unicompartmental knee replacement is known wherein a single compartment of the knee is surgically restored. Typically, the medial or lateral portion of the tibio-femoral joint is replaced without sacrificing normal remaining structure in the knee. For instance, U.S. Pat. No. 4,340,978 to Buechel et al discloses a unicompartmental knee replacement device including a tibial platform secured to the tibia and having a track for receiving a bearing insert. A femoral component is attached to one of the condylar surfaces of the femur and is provided with a generally convex spherical inferior surface for engaging the superior surface of the bearing insert. Similar unicompartmental knee implants are shown in U.S. Pat. No. 4,743,261 to Epinette; U.S. Pat. No. 4,309,778 to Buechel et al; U.S. Pat. No. 4,193,140 to Treace; U.S. Pat. No. 4,034,418 to Jackson et al; and U.S. Pat. No. 3,852,830 to Marmor.
The non-hinged knee implants previously discussed, while possessing advantages over the hinged devices, nonetheless are characterized by numerous drawbacks. Many of the prior art prostheses require the removal of a great deal of bone from the femur and tibia in order to accommodate the implant, thus complicating and prolonging the surgical procedure and reducing the amount of bone available in reserve should subsequent restorative measures be required. Additionally, alignment of the prosthesis components is extremely difficult, and even small misalignments lead to an imbalance of the forces transmitted from the femoral component to the tibial component. The asymmetric distribution of load on the plateaus of the tibial component can result in tibial loosening and failure of the prosthesis. Moreover, inadequate fixation of the prosthesis can occur, possibly resulting in the prosthesis twisting loose from the implanted position.
The misalignment and anchoring problems associated with conventional prostheses are due in part to the fact that the prosthesis is secured in place by means of cement applied to the prothesis after a trial fit and prior to actual fixation. Although the joint may have been precisely prepared to accept the prosthesis, and although the femoral and tibial components may have been accurately aligned during trial fitting, deviation from the desired location is apt to occur when the prosthesis is removed to place cement on the prepared bone surface and then replaced on the bone surface.
The prior art prosthetic devices have another disadvantage in that excess cement tends to escape from between the bone and the implant around the edges of the implant. The excess cement, if not removed, may deteriorate and crumble, thereby becoming a source of possible irritation. Additionally, cracking and breakage of the cement may lead to loosening of the cement bond, thus jeopardizing the integrity of the cemented parts. Therefore, additional steps are typically undertaken to remove the excess cement squeezed out during the surgical procedure.
Several of the prior art prosthetic devices previously referred to are illustrative of the foregoing deficiency. For example, Buechel et al ('978) is directed to a unicompartmental knee prosthesis wherein the prosthesis components must be removed after a satisfactory trial fit to allow cement to be placed on the bone surfaces. The components are then reintroduced into the surgical site, located in the pre-established position and firmly held in compression with the bone until complete polymerization has been obtained. Excess cement is removed from the edges of the prosthetic component by a scalpel and curette. Similarly, Charnley teaches inserting cement through a hole cut into the head of the tibia. The anterior end of the tibial component is then elevated to cause the posterior end to press into the tibia bone so as to close the posterior route of escape for the cement. Treace discloses a knee prosthesis for fixation to the femur including a curved body provided with a plurality of cement holding rings fixedly attached to and extending upwardly from the upper surface of the body. The femur must be prepared by drilling slots therein for receiving the cement holding rings subsequent to cement being injected into the slots.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to overcome the above mentioned disadvantages of the prior art.
Another object of the present invention is to provide a prosthesis permitting cement to be supplied between the prosthesis and the prepared tissue surface after the prosthesis has been positioned on the tissue surface.
A further object of the present invention is to provide a prosthesis which can be implanted utilizing arthroscopic surgical techniques.
An additional object of the invention is to utilize a rim to control rotation of a femoral prosthesis during fixation by cement.
The present invention has another object in that unicompartmental prosthetic total knee replacement can be performed with the use of modular tibial components, bearing inserts and femoral components.
Another object of the invention is to provide a tibial prosthesis receiving bearing inserts of varying thicknesses to provide accurate alignment.
According to the present invention, therefore, a prosthesis includes a body having a fixation surface for placement adjacent the surface of the tissue, such as bone, to which the prosthesis is to be affixed. A recess is formed in the fixation surface of the body such that, when the fixation surface is positioned adjacent the bone surface, the recess is substantially closed off by the bone surface to define a cement receiving chamber. Securing means such as a screw or post member secures the body member in position on the bone surface. A channel formed in the prosthetic body establishes communication between the cement receiving chamber and the exterior of the body member, and cement is introduced into the cement receiving chamber via the channel. Thus, the prosthesis may be cemented in place while in the desired position and secured against movement. The invention further contemplates a wall or rim extending from the fixation surface for penetrating the bone surface when the prosthesis is in position thereon so as to provide additional stability. The rim extends along and at least partially surrounds the recess to serve as a seal or trap for preventing release of cement from the cement receiving chamber thereby augmenting cement pressurization.
Some of the advantages of the present invention over the prior art are that the prostheses can be placed using arthroscopic surgical techniques, textured surfaces enhance the prosthesis-cement interface, the asymmetrical shape of the tibial prosthesis component provides optimal coverage of the tibial plateau, the modular design allows variation of final tibial thickness, the femoral prosthesis component does not interfere with the patella, two spaced tapered posts on the femoral prosthesis component provide rotational stability, a rim extending along a recess in the fixation surface of the femoral prosthesis component resists rotation of the implant and augments cement pressurization, a rim extending along a recess in the fixation surface of the tibial prosthesis component holds the implant in place and augments cement pressurization, and a portal or channel through the tibial and femoral prosthesis components allows placement of bone cement between the implant and the prepared bone surface after the implant has been accurately positioned on the bone surface without moving the implant.
Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the knee joint prosthesis of the present invention with the femur and tibia shown in phantom.
FIG. 2 is a top plan view of the tibial prosthesis component of the present invention.
FIG. 3 is a bottom plan view of the tibial prosthesis component of FIG. 2.
FIG. 4 is a cross-section of the tibial prosthesis component taken along line 4--4 of FIG. 2.
FIG. 5 is an enlarged fragmentary view taken along line 5--5 of FIG. 4.
FIG. 6 is a broken side view of the tibial prosthesis component with a bearing insert shown in phantom.
FIG. 7 is a top view of a bearing insert of the present invention.
FIG. 8 is a section of the bearing insert taken along line 8--8 of FIG. 7.
FIG. 9 is a bottom plan view of another embodiment of the tibial prosthesis component of the present invention.
FIG. 10 is a side view of a further embodiment of the tibial prosthesis component of the present invention.
FIG. 11 is a side view of the femoral prosthesis component of the present invention.
FIG. 12 is a top view of the femoral prosthesis component of FIG. 11.
FIG. 13 is an anterior view of the femoral prosthesis component of FIG. 11.
FIG. 14 is an enlarged fragmentary view in section taken along line 14--14 of FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention relates to prostheses for implant in the body and is particularly described in connection with a prosthesis or implant for the knee joint. A preferred embodiment for a knee joint prostheses implant according to the present invention is shown in FIG. 1 and includes a tibial prosthesis component 12, a femoral prosthesis component 14 and a bearing insert 60. The tibial component 12 is affixed to a suitably prepared site on the upper plateau 16 of the tibia 18, shown in phantom. The femoral component 14 is affixed to a suitably prepared site on a condyle 20 of a femur 22, shown in phantom.
FIGS. 2-6 show a preferred embodiment of the tibial component 12 including a body 24 which, viewed from the top, has a generally asymmetrical, D-shaped configuration with an arcuate side wall 26 joined to a generally planar side wall 28 via curved side wall sections 29. The body 24 has a top or upper surface 30 connecting the upper edges of the planar side wall 28, the arcuate side wall 26 and the curved side wall sections 29. As best shown in FIG. 3, the body has a bottom or fixation surface 32 connecting the lower edges of the planar side wall 28, the arcuate side wall 26 and the curved side wall sections 29. The planar side wall 28, the arcuate side wall 26 and the curved side wall segments 29 together define a peripheral wall, with the bottom surface 32 having a periphery defined by the peripheral wall.
A cavity 34 is formed in the top surface 30 of the body 24 defined by a planar cavity side wall 36 joined to an arcuate cavity side wall 38 by curved cavity wall end sections 40 and a cavity bottom wall 42 joining the lower edges of cavity side walls 36, 38 and 40. An inwardly tapered through hole 44 is formed in the cavity bottom wall 42 and extends substantially perpendicularly through the body 24.
With particular reference to FIGS. 2 and 4, each curved cavity wall end section 40 has a lip 46 projecting from the curved cavity wall section into the interior of the cavity 34. As shown in detail in FIG. 5, the lip 46 has a chamfered surface 48 extending downwardly from the top surface 30 of the body at an angle of approximately 45°. The surface 48 terminates in a vertical cavity facing surface 50 which joins curved cavity wall section 40 via a horizontal surface 52. Curved cavity wall sections 40 extend downwardly from horizontal surface 52 to cavity bottom wall 42 at an angle of approximately 20° toward the interior of the cavity 34 such that lips 46 form grooves in the side wall curved end sections 40.
With reference to FIG. 6, it can be seen that the top surface 30 of the body 24 is generally flat except for a sloping surface 54 at an anterior portion extending from a straight edge 56 located on the top surface downwardly at an angle of approximately 30° with respect to the parallel top and bottom surfaces to meet the side walls of the body. A through hole 58 is formed in the anterior portion to extend through the body from sloping surface 54 to bottom surface 32 at an angle of approximately 60° with respect to the bottom surface 32 and perpendicular to surface 54.
A bearing insert 60 closely configured to the peripheral dimensions of the cavity 34, as defined by cavity side wall sections 36, 38 and 40, includes a body defined by a planar insert side wall 62 joined to an arcuate insert side wall 64 by curved insert wall end sections 66. The body has an upper surface 68 joining the upper ends of the insert side walls 62, 64 and 66, while the lower ends of the side walls are joined by a lower surface 70.
Upper surface 68 is slightly concave when viewed from the side, as shown in FIGS. 6 and 8. Each curved end section 66 is provided with a flexible protruding lip 72 extending upwardly and outwardly from the lower surface 70 toward the upper surface 68 at an angle of approximately 20° with respect to the end section 66, as best illustrated in FIG. 8, to terminate in an upper edge 73 spaced from the side wall curved end section 66. The insert 60 has a configuration mating with the configuration of cavity 34 and is received in the cavity 34, as shown in phantom in FIG. 6, with the insert bottom surface 70 resting on the cavity bottom wall 42, insert side walls 62, 64 and 66 in close abutment with the respective cavity side walls 36, 38 and 40 and the lips 72 engaged in the grooves beneath lips 46 to securely retain the insert in position within the cavity. A range of inserts ranging in thickness, for example, from approximately 8 mm to 15 mm as measured from the insert upper surface 68 to the insert lower surface 70, is provided so that the proper fit can be attained. The upper surface 68 of the insert will be elevated with respect to the top surface 30 of the tibial component body by varying amounts depending upon the thickness of the particular insert. Preferably, the bearing insert is integrally fabricated in a unitary manner of ultra-high molecular weight polyethylene.
As particularly shown in FIG. 3, the fixation surface 32 of the body 24 has a recess 74 therein defined within the confines of the side walls 26, 28 and 29 of the body. A channel or portal 76 connects the recess 74 to the exterior of the body and extends from the recess 74 through the arcuate side wall 26 at the anterior portion of the body. The recess 74 and the channel 76 share a common end wall 78 which defines the depth to which the recess and channel extend above the bottom surface 32 into the interior of the body. The end wall 78 being spaced from the bottom surface 32 to define a cavity between the tibial plateau and the end wall when the bottom surface is positioned on the tibial plateau. The peripheral wall has a lower or bottom portion that extends beyond the end wall in the direction of the bottom surface, and the channel 76 extends through the lower portion of the peripheral wall. A land 80 along the fixation surface 32 isolates the through hole 44 from the recess 74, while a land 82 along the fixation surface 32 isolates the through hole 58 from the recess 74. A rim 84 projects from the bottom surface 32 spaced from but following the curve of arcuate side wall 26 with an interruption at the location of channel 76. As is most clearly depicted in FIGS. 4 and 5, the rim 84 is triangular in cross-sectional configuration, with the apex of the triangle forming a sharp bottommost edge 86 for the body. The rim 84 defines a wall extending along the recess 74 and at least partially surrounding the recess.
The tibial component 12 is provided in a range of sizes, for example, with the dimension A of the body ranging from approximately 37.5 mm to approximately 54 mm and the dimension B ranging from approximately 21 mm to approximately 33 mm, as shown in FIG. 2, to accommodate a range of sizes for optimal coverage of the tibial plateau. The asymmetrical "D" configuration of the body further contributes to optimal tibial plateau coverage in order to present a contact area for the femoral component coinciding with that of a normal knee.
The tibial component 12 is particularly designed to be affixed to a suitably prepared tibial plateau through arthroscopic surgical techniques; however, the tibial component can be used in normal open surgery procedures for prosthetic knee replacement. In use, the body can be grasped by an appropriate surgical instrument and placed in position on the tibial plateau with the bottommost edge 86 resting upon the tibial plateau. Once the desired position for the body on the tibial plateau has been established, the body is affixed by a cancellous bone screw 88 inserted at an angle through hole 58 and into the anterior portion of the tibia as illustrated in FIG. 1. A second cancellous bone screw 90 can be inserted through the body into the tibia via through hole 44 if desired. The recess 74 formed in the bottom surface 32 of the body define, together with the tibial plateau, an enclosed cement receiving chamber which communicates with the exterior of the body through channel 76. A bone cement, preferably low viscosity methyl-methacrylate, is injected into the chamber through channel 76 to form a physical bond between the body and the tibial plateau. It can be seen, therefore, that the tibial component can properly be positioned prior to the application of cement and need not be moved or disturbed in any manner thereby assuring precise and accurate positioning. The cement can be inserted in the cement receiving chamber by means of a needle or syringe to be compatible with arthroscopic techniques. The rim 84 forms a seal around the cement receiving chamber with respect to the tibial plateau to augment filling of the cement receiving chamber, and the rim 84 penetrates the tibial surface to establish a seal preventing escape of cement from the chamber while the bottom surface 32 engages the tibial plateau. Additionally, the rim 84 stabilizes the position of the tibial component on the tibial plateau. The lands 80 and 82 along the bottom surface 32 isolate the respective fixation screws from the cement so that the screws can be removed, if necessary. The bottom surface 32 and the wall 78 of recess 74 are textured to enhance the interface between the body and the cement. The invention contemplates a right medial/left lateral orientation for the tibial component in addition to the left medial/right lateral illustrated herein. A suitable bearing insert 60 can be inserted after the body has been implanted, or the insert 60 can be mounted in the body prior to implanting the body.
Another embodiment of a tibial component according to the present invention is shown in FIG. 9 wherein a body 88 is essentially the same as body 24 except that through hole 44 has been eliminated and the recess 90 follows the arcuate wall 26, as does end wall 92. The body 88 thus accommodates only a single screw which, due to its position at the anterior portion of the implant, provides sufficient fixation.
A further embodiment of the present invention is shown in FIG. 10 and is essentially the same as the tibial component of FIG. 9 except that a post 96 depends from the end wall 92 of the recess 90 at substantially the same position as through hole 44 shown in FIG. 3. The post 96 is intended to be inserted into a corresponding drilled hole in the tibial plateau. Preferably, the post 96 is tapered to allow a press fit into the corresponding hole.
The femoral component 14 of the prosthesis of the present invention is illustrated in FIGS. 11-15 and includes a body 100 having a curved configuration defining an arcuate outer bearing surface 102 with an anterior or distal end 104 and a posterior end 106. The bearing surface 102 is generally polycentric, that is, the surface lies on arcs of circles having more than one center and more than one radius to approximate the natural articulating surface of a femoral condyle. The posterior end 106 curves somewhat sharply while the anterior end 104 curves somewhat gradually. In other words, the radius of an imaginary circle in which the anterior end 104 lies is greater than the radius of an imaginary circle in which the posterior end 106 lies. Body 100 further includes an inner fixation surface which joins the bearing surface 102 at side and end edges. The fixation surface includes a planar posterior section 118, a planar chamfer section 120 and a planar distal section 122. The posterior and distal sections 118 and 122 are oriented substantially perpendicular with respect to each other, while chamfer section 120 is oriented at an angle of substantially 45° with respect to the posterior and distal sections.
As shown in the top view of the femoral component 14 in FIG. 12, the body 100 has a generally straight medial side edge 110 and a generally straight lateral side edge 112 parallel to edge 110 but about one half the length of the edge 110. The side edge 112 is joined to side edge 110 via a generally polycentric curved edge 114. An arcuate posterior edge 116 joins the opposite ends of the side edges 110 and 112. Side edge 110 extends along the sides of the posterior, chamfer and distal sections of the fixation surface. Side edge 112 extends along the sides of the posterior and chamfer sections and along a portion of the side of the distal section, the curved edge 114 extending along the remaining portion of the side of the distal section.
As shown in FIGS. 11 and 12, a recess 124 is formed in the chamfer section 120 and the distal section 122 of the fixation surface. A side wall 126 of the recess 124 generally follows the side edges 110, 112 and 114 of the body 100, running generally parallel thereto but separated therefrom by a portion of the fixation surface. The recess is provided with a bottom surface 128 and terminates along a bottom edge 130 of the posterior section 118. A channel 132 is formed in the bottom surface 128 of the recess 124 extending generally parallel to the side edge 110 of the body 100 in the distal section 122 and through the curved side edge 114 of the body to establish communication with the exterior.
Posts 136 and 138 project upwardly substantially perpendicular to bottom surface 128, preferably at an inclination of 5° from the plane of the posterior section 118. The posts 136 and 138 are generally cone-shaped and have respective tapered top ends 140 and 142. As depicted in FIG. 11, the post 136 is longer than the post 138, the post 138 being around two-thirds the length of post 136. A rim 144 projects from the fixation surface, spaced from but lying generally parallel to side edges 110, 112 and 114 of the body 100. As can be seen in FIG. 12, the rim 144 also lies generally parallel to the side wall 126 of the recess 124 so as to at least partially surround the recess 124 along the chamfer section 120 and the distal section 122. The rim 144 is preferably triangular in cross-sectional configuration to provide a relatively sharp edge 148 as was discussed in connection with rim 84 for the tibial component 12 and as shown in FIG. 14. A semi-circular indentation 150 is provided on each side of the body 100 in distal section 122 proximate side edges 110 and 112 as shown in FIGS. 11, 12 and 13.
The femoral component 14 is adapted to be positioned on a condylar surface of the femur after the surface has been suitably cut and shaped to conform to the fixation surface of the body 100. The femoral component may be positioned by means of open or arthroscopic surgical techniques with the indentations 150 engaged by a surgical tool for placement of the femoral component on the prepared femoral condyle. The posts 136 and 138 are fitted into drilled holes in the cut distal end of the femoral condyle, the tapered upper ends 140 and 142 of the posts allowing for a press fit. With the femoral component in the proper position on the femoral condyle, the rim 144 penetrates the bone to enhance securement and forms a seal with respect to the bone around the cement receiving chamber formed by the recess 124 and the surface of the bone. Cement is introduced into the chamber through the channel 132 by means of a syringe, a needle or the like as discussed in connection with the tibial component. The rim 144 inhibits rotation of the femoral component as do the posts 136 and 138. Preferably, the fixation surface and the recess bottom surface 128 are textured to enhance the interface between the femoral component and the cement. The tibial and femoral components are preferably fabricated of metal, the preferred material for the tibial component being implant grade titanium, and for the femoral component cobalt-chromium.
The surface 102 of the femoral component cooperates with the concave surface 68 of bearing insert 60 to allow the same freedom of movement afforded by a healthy knee. The nonmetallic insert 60 provides a bearing surface for the metallic femoral component similar to the cartilage in a natural knee joint. The plastic material from which the insert is fabricated provides a low coefficient of friction between the contacting surfaces and minimizes the rate of wear of the contacting surfaces of the components. As discussed in connection with the tibial component, it is contemplated that the femoral component be available in a number of sizes, and in right medial/left lateral and left medial/right lateral versions to prevent interference with the patella.
The knee joint prosthesis of the present invention can be used in conventional open, total knee replacement surgical procedures but is particularly useful for implant using arthroscopic surgical techniques due to the simplified cementing procedures and the stability permitted by the tibial and femoral prosthesis components coupled with the modular nature thereof and the use of bearing inserts of varying sizes to produce desired tibial thicknesses or heights. Method and apparatus for implant of the knee joint prosthesis of the present invention are disclosed in an application filed concurrently herewith by the same inventors, entitled "Methods and Apparatus for Arthroscopic Prosthetic Knee Replacement", the disclosure of which is incorporated herein by reference.
Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense. | A knee joint prosthesis includes tibial and femoral components and a bearing insert designed for unicompartmental prosthetic total knee replacement and can be implanted using arthroscopic surgical techniques. The tibial and femoral prosthesis components have channels or portals therethrough allowing supply of cement to the prosthesis-bone interface after the prosthesis has been positioned for implant. Recesses communicate with the channels and cooperate with the bone surfaces to form cement receiving chambers, and rims at least partially surround the recesses to penetrate the bone surfaces to stabilize the positions of the prostheses and form seals preventing cement from escaping from the prosthesis-bone interfaces. | 0 |
BACKAROUND OF THE INVENTION
[0001] The microbial, plant, and animal (e.g. invertebrates) kingdoms constitute rich natural repositories of active ingredients with varied physico-chemical and medicinal properties. The U.S. and European pharmacopeias are replete with examples of medicaments derived from natural sources. See U.S. Pharmacopeia 1995 (United States Pharmacopeial Convention, Inc., 1994) and Martindale, The Extra Pharmacopeia 31 (Royal Pharmaceutical Society, 1996). Many antimicrobial agents (e.g., penicillins, cephalosporins, and aminoglycosides), antifungals (e.g., amphotericin B and nystatin), anti-parasitics (e.g., quinine), cardio- and vaso-active agents (e.g., cardiac glycosides-digoxin, ergot alkaloids, nicotine, and oxytocin), anti-inflammatory agents (e.g., aspirin), muscarinic (e.g., acetylcholine) and antimuscarinic (e.g., atropine and scopolamine) agents, neuroactive agents (e.g., curare, physostigmine, and opiates), anticoagulants (e.g., heparin), antineoplastic agents (e.g., vinca alkaloids, taxol, and podophyllotoxin derivative etoposide), and hormones (e.g., estrogens, androgens, progestins, peptide hormones, and growth factors) were discovered as natural products. See, e.g., Goodman & Gilman's The Pharmacological Basis of Therapeutics (9th Edition McGraw-Hill, 1996). These examples suggest that some active components in plant extracts may also be purified and still retain their biological potency.
[0002] In most of the above examples, the salient ethnopharmacological properties of the compound were characterized in known pharmacological systems and assays only upon isolation of the compound from the natural source. See, e.g., Turner, R. A. Screening Methods in Pharmacology (Academic Press, 1965) and Turner, R. A., Peter Hebborn Screening Methods in Pharmacology, (Vol. II, Academic Press, 1971). While the process of determining or substantiating activities of plant extracts may be discovered by the screening of their individual components, many of these extracts may have additional pharmacological activities that may not be evident from the extract's known, if any, ethnopharmacological background of its individual components, (e.g., the extract's ability to affect signal transduction to the nucleus, alter the trafficking of cell surface receptors, and regulate genomic events).
[0003] The characterization of defined active natural compounds, either derived from natural sources or produced synthetically or semisynthetically, constitutes the pharmacological basis for much of Western Medicine. The process of distilling an ethnopharmacologically active plant extract down to a single active principal, however, may result in a loss of biological activity for a number of reasons (e.g., a particular compound is unstable during extraction or in the purified form, the compound may react with chemical entities in the extract during purification, the compound is fractioned out during purification, or, more importantly, the fundamental basis for ethnopharmacology does not always reside in a single active compound being present in the extract but rather is a result of the interaction of two or more active compounds found in the extract). Thus, the likelihood that more than one compound present in a plant extract could contribute to a net pharmacological response of the extract, as well as a genomic means to identify such compounds in a natural product, is a novel pharmacological concept.
[0004] The present invention provides for a genomic screen in which an extract from a plant may be characterized for its potential biological properties which may or may not be related to the known, if any, ethnopharmacological properties of the extract. The present invention represents a novel approach to the analysis of the potential mechanism(s) of action of plant extracts, as the underlying basis for therapeutic efficacy, and a means for identifying the individual compound(s) which elicit the discovered biological property in order to identify a new pharmaceutical or new pharmaceutical use for an existing pharmaceutical.
SUMMARY OF THE INVENTION
[0005] In one aspect, the invention features a method of identifying a pharmaceutical, the method comprising the steps of: administering a plant extract to a cell type; isolating protein or RNA (e.g., messenger RNA) from the plant extract treated cell type; identifying which of the protein or RNA isolated from the plant extract treated cell type is not present in the same concentration in the untreated cell type (e.g., a protein or RNA which is up-regulated, down-regulated, turned on, or turned off in the cell type by the plant extract); administering compound(s) to the cell type, wherein the compound(s) are found in the plant extract; isolating protein or RNA from the compound(s) treated cell type; and identifying which of the compound(s) also result in the expression or suppression of the protein or RNA which is not present in the same concentration in the untreated cell type.
[0006] What is meant by “plant extract” is a collection of different natural compounds which are isolated from a plant (e.g., from the leaves, bark, fruits, flowers, seeds, or roots). Examples of such an extract is an extract from the tree ginkgo biloba. What is meant by “cell type” is either an isolated cell (e.g., derived from an organism such as a human or animal) or cells contained within a tissue or an organ from an organism. The cell type may be a normal cell or a diseased cell (e.g., a cell which is pathologically or physiologically different from its normal cell type, such as a tumor cell).
[0007] The plant extract and compound(s) may be administered to the cell type either in vitro or in vivo (e.g., to an intact animal from which the cell type is subsequently derived following treatment with the plant extract or compound(s)). When administered in vitro, the protein or RNA, for example, may be isolated immediately following or up to a day following administration of the plant extract or compound(s). When administered in vivo, the protein or RNA, for example, may be isolated immediately following or up to a day following the administration of the plant extract or compounds to the animal. The protein may remain within the cell type or secreted outside the cell type. Examples of such proteins include receptors, growth factors, enzymes, or transcription factors.
[0008] In another aspect, the invention features a method of determining the genomic response of a cell type to a plant extract, the method comprising the steps of: administering the plant extract to the cell type; isolating protein or RNA (e.g., messenger RNA) from the plant extract treated cell type; and comparing the protein or RNA isolated from the plant extract treated cell type to protein or RNA isolated from the untreated cell type.
[0009] In one embodiment, the method further comprises the step of identifying which of the protein or RNA isolated from the plant extract treated cell type is not present in the same concentration in the untreated cell type. In a further embodiment, the method further comprises sequencing the protein, RNA, or protein encoded by the RNA, identified from the plant extract treated cell type which is not present in the same concentration in the untreated cell type. In a still further embodiment, the method further comprises identifying the gene encoding the protein or RNA identified from the plant extract treated cell type which is not present in the same concentration in the untreated cell type.
[0010] In another embodiment, the cell type is associated with a known biological target (e.g., activation site) of the plant extract. For example, if the plant extract is known to treat asthma, cancer, circulation, or neurological disorders, then the cell type used is a lung cell, cancer cell, vascular cell, or neuronal cell, respectively.
[0011] Other features and advantages of the present invention will be apparent from the detailed description of the invention and from the claims.
DETAILED DESCRIPTION OF THE INVENTION
[0012] It is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
[0013] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Also, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.
[0014] Plant Extracts and Its Individual Compounds
[0015] Plant extracts may be prepared by standard chemical extraction techniques (e.g., using water to extract hydrosoluble compounds, alcohols and acetone to extract liposoluble compounds, or mixtures thereof). The extract may then be further purified to decrease the number of compounds in the extract, or even isolate a single compound or compound class, by using standard techniques such as chromatography and crystallization. See, e.g., Ginkgolides—Chemistry, Biology, Pharmacology and Clinical Perspectives, edited by P. Braquet (J. R. Prous, Science Publishers, Barcelona, Spain 1988); Okabe, J. Chem. Soc. (c) p. 2201 (1967); and Nakauishi, Pure & Applied Chemistry 19 : 89 ( 1967 ).
[0016] Identification of Genomic Events by Isolating Protein
[0017] The target cell types, in culture, are harvested before and after exposure to a set concentration(s) of a plant extract (e.g., an extract of ginkgo biloba). The procedure may be similarly applied to cells from a target tissue or organ of an organism that has been exposed to a dose, or multiple doses, of a plant extract. The cells are lysed, and the proteins are solubilized in detergenized buffers (e.g., Tween 20, SDS, or NP-40 available from Sigma Chemicals, St. Louis, Mo.). The proteins are separated by two-dimensional gel electrophoresis, with isoelectric focusing in the first dimension and a gradient gel electrophoresis in the second dimension. See, e.g., Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 10.3.1-10.4.5 (John Wiley & Sons, 1987). This is an extremely powerful method for examining complex mixtures of proteins (e.g., as many as 1500 proteins may be resolved in a single 2-D Gel). See, e.g., O'Farrell, P. H., J. Biol. Chem. 250:4007-4021 (1975).
[0018] The pattern of protein expression may be visualized by Coomasie Blue staining (Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 10.6.1 (John Wiley & Sons, 1987)) or silver staining (Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 10.6.1-10.6.3 (John Wiley & Sons, 1987)). The cells may also be pulsed with a radio-labelled amino acids, e.g. S 35 -Methionine (Amersham Corp., Arlington Heights, Ill.), and the pattern of labelled protein expression on the 2-D Gels is detected by autoradiography. In the case where the pattern of post-translationally modified proteins are examined, e.g., phosphorylated proteins, a radioactive phosphate donor, such as p 32 -γATP (Amersham Corp., Arlington Heights, Ill.), is added to the incubation medium, and the pattern of phosphorylated protein on the 2-D gels may then be visualized by autoradiography. See, e.g., Hansen, K., et al., Electrophoresis 14:112-116 (1993); and Guy, R., Electrophoresis 15:417-440 (1994). In the latter case, unlabelled phosphoprotein expression may be visualized using phosphotyrosine or phosphoserine antibodies upon transfer of the gels to nitrocellulose. See, e.g., Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 10.7.1-10.8.6 (John Wiley & Sons, 1987).
[0019] Specific genomic events are detected by comparing the pattern of protein expression in cells before and after exposure to the plant extract. Specific protein spots on the 2-D gels that show either an enhancement or a reduction in expression, as evident from the intensity of the stain on the protein map, represents changes in genomic activity induced by components in the plant extract. The method is highly reproducible and can provide a means of collecting small amounts of extremely pure proteins for amino acid sequence analysis using standard techniques (i.e., Edmans amino-terminal degradation chemistry). See, e.g., Graven, et al., J. Biol. Chelm. 269:24446 (1994).
[0020] For proteins that are expressed at low quantities wherein sufficient amounts of the material may not be obtain for peptide sequencing, the protein spots may be excised from the 2-D gel and used directly for immunization in rabbits for antibody production. See Harlow, E. & Lane, D., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, 1988, pp. 61. The availability of an antibody allows the immunoaffinity purification of larger amounts of the regulated protein for peptide sequence identification.
[0021] From the peptide sequence, oligonucleotides may be synthesized based on redundant or most preferred genetic code for use as probes to screen a cDNA library to obtain the full length coding sequence of the gene(s). See, e.g., Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, (2nd Edition, Cold Spring Harbor Laboratory Press, 1989).
[0022] Identification of Genomic Events by Isolating mRNA
[0023] Another method for detecting changes in genomic events in response to a plant extract is to monitor messenger RNA (mRNA) changes in a cell (Liang, P. & Pardee, A. B., Science 257:967-971 (1992)). The cell will be exposed to a concentration of the plant extract in culture, or the cells from a target tissue or organ in an organism can be exposed locally or systemically with a dose or multiple doses of the plant extract for a defined period and subsequently extracted.
[0024] The mRNA will be prepared by routine total RNA extraction methods as described in Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 4.1.2-4.3.4 (John Wiley & Sons, 1987). From this preparation, Poly(A+) RNA may be prepared by oligo-dT chromatography (Aviv, H., & Leder, P., J. Mol. Biol. 134:743 (1972)) as described in Ausubel, A. M., et al., Current Protocols in Molecular Biology, pp 4.5.1-4.5.3 (John Wiley & Sons, 1987).
[0025] Two pools of mRNA are prepared, i.e., one from cells before and the other after exposure to the plant extract. Specific genomic events are represented in both pools depending on whether a suppression of gene activity or an activation of gene expression is induced by the plant extract. In the case where a gene is down-regulated in response to the plant extract, the mRNA will be present in higher quantities in the mRNA pool derived from the control cells. In the case where a gene is up-regulated in response to the plant extract, the mRNA will be present in higher quantities in the mRNA pool obtained from the plant extract treated cells. A number of techniques may be employed to identify mRNA populations that are up-regulated or down-regulated, e.g., subtractive hybridization or differential display.
[0026] (a) Subtraction Hybridization
[0027] Subtractive hybridization techniques (Lee, S. W., et al., Proc. Natl. Acad. Sci. 88:2825 (1991)) have been developed wherein the mRNA from one of the two pools is converted to first strand cDNA (antisense) by using oligo-dT primers, attached to either cellulose beads or free primers, and reverse transcriptase. See, e.g., Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, pp 10.46 (2nd Edition, Cold Spring Harbor Laboratory Press, 1989). In the case where the first strand is attached to cellulose beads, subtractive mRNA chromatography may be effected by passing the second mRNA pool through the column. mRNA represented in both pools will hybridize (i.e., mRNA from the second pool will hybridize to the antisense cDNA on the column and will be retained on the column). The flow through, which does not hybridize in the column, will contain mRNA species arising from an alteration in genomic activity from the effect of the plant extract on the cells. A cDNA bacteriophage library can then be prepared with mRNA from the flow-through fraction. See, e.g., Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, pp 8.11-8.45 (2nd Edition, Cold Spring Harbor Laboratory Press, 1989).
[0028] Specific clones not represented in the first mRNA pool are identified as non-hybridizing plaques if the library is screened with an P 32 -end-labelled probes generated from the first pool. Other comparable strategies have also been described (Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, pp 10.41, 10.42 (2nd Edition, Cold Spring Harbor Laboratory Press, 1989).
[0029] The genes involved will be identified by DNA sequencing of the cDNA clones. See, e.g., Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, pp 13.3-13.20 (2nd Edition, Cold Spring Harbor Laboratory Press, 1989).
[0030] (b) mRNA Differential Display
[0031] This method is well described in the art. See, Liang, P., & Pardee, A. B., Science 257:967-970 (1992); Callard, D., et al., BioTechniques 16:1096-1103 (1994); Chen, Z., et al., BioTechniques 16:1003-1006 (1994); and Zhao, S., et al., BioTechniques 20:400-404 (1996). Partial cDNA sequences from mRNA prepared from the plant extract or treated and untreated cells are prepared by reverse transcription. See, e.g., Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, Book 2, pp 10.46 (2nd Edition, Cold Spring Harbor Laboratory Press, 1989) and amplified by polymerase-chain reaction, e.g., using a 5′-T 11 CA as a 3′-primer and a short (6-7 base) 5′-primer. The amplification reaction employs an α 35 S-DATP label. The labelled, short PCR-amplified fragments from each mRNA pool are then fractionated (e.g., displayed) on a DNA sequencing gels. Bands not represented in equal intensity in one pool or the other are excised from the gel, reamplified, and used as a probe for screening a cDNA library, as described above, to identify the genes that are regulated by the plant extract.
[0032] Use
[0033] In this manner, a gene profile for a specific cell type in response to exposure to a particular plant extract of pharmacological interested may be catalogued without knowing the actual components in the plant extract. The utility of the plant extract can then be converted with the reported role of some of these genes in specific biological processes. In this manner, the therapeutic potential of the product may be extended beyond its known ethnopharmacological properties, or its known ethnopharmacological property can be genomically verified. Furthermore, similarly acting individual compound(s) in the extract can subsequently be identified as therapeutics based on the extract's activity on a certain set of genomic events.
Other Embodiments
[0034] It is to be understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the claims. | The invention features a method of identifying a pharmaceutical comprising compounds found in a plant extract by utilizing a genomic screen of the plant extract. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to an open-end spinning unit of the type including a fiber guide disc arranged so that at least its largest diameter section extends into the opening of the spinning rotor.
Open-end spinning units with stationary fiber guide discs are disclosed in German Auslegeschrift [Published Patent Application] No. 1,111,549. In the arrangement disclosed therein, the fiber guide disc is arranged with respect to the spinning rotor so that a narrow space remains between the surface of the fiber guide disc and the inner bottom surface of the rotor. The yarn formed in the fiber collecting trough is guided through this space. Consequently, the fiber guide disc serves the purpose of providing sufficient separation between the fibers entering the fiber collecting trough and the yarn removed therefrom.
The drawback of the known arrangement is that the stationary fiber guide disc substantially influences the movement of air in the spinning rotor and leads to turbulences and eddies in the region of the fiber collecting trough. The essential cause of this interference with the spinning process is the substantial difference in speed between the fiber guide disc and the fiber collection trough of the spinning rotor which rotates at high speed.
In order to remove the above-described drawbacks, an open-end spinning unit has been developed which has a break-up roller arranged coaxially with the spinning rotor and in which the break-up roller is provided with a fiber guide edge at its portion facing the spinning rotor. The fiber guide edge together with the associated housing edge forms a substantially radial annular gap through which the break-up roller brings separated fibers to the spinning rotor. Such an arrangement is disclosed in German Offenlegungsschrift (Laid-Open Application No. 2,064,697.
The drawback of this known open-end spinning unit is that the speed of the fiber guide disc is not independent of the speed of the break-up roller since the latter, in view of conditions in its combing range, cannot rotate at any desired high speed. In this case there consequently likewise exists a relatively great difference in speed between the associated housing edge and the spinning rotor.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an open-end spinning unit with a fiber guide disc in which -- independently of whether the break-up roller is arranged coaxially or offset with respect to the spinning rotor -- more favorable spinning conditions exist in the region of the intake section of the spinning rotor as well as in the region of the fiber collecting trough.
This and other objects according to the invention are accomplished by constructing the fiber guide disc as an independent, rotatably mounted unit which is driven without contact by one of the rotating components of the spinning unit which lie opposite thereto, i.e., the spinning rotor or the break-up roller.
In order to produce the most favorable spinning conditions it is advisable to make variable the drive energy which is transmitted to the fiber guide disc.
Depending on the configuration of the open-end spinning unit, the fiber guide disc may be driven indirectly by the break-up roller or by the spinning rotor. If the break-up roller is mounted in a manner such that it is axially offset with respect to the spinning rotor, as disclosed in German Published patent application No. 1,111,549, the fiber guide disc can be driven only via the spinning rotor unless additional expenditures are made.
With a coaxial arrangement of the break-up roller and the spinning rotor, the fiber guide disc is advisably also driven via the spinning rotor since, as already mentioned above, the peripheral speed of the break-up roller is substantially lower than that of the spinning rotor.
In a spinning unit with a break-up roller arranged eccentrically with respect to the spinning rotor, the fiber guide disc, which is coaxial with the spinning rotor, is advisably directly mounted in the housing of the break-up roller; in spinning units where the break-up roller is coaxial with the spinning rotor, the fiber guide disc is mounted in the break-up roller itself.
In a particularly simple embodiment of the present invention, the fiber guide disc is provided with take-up, or fluid coupling, vanes and is driven by the circulation of air produced by the spinning rotor. The take-up vanes are here advisably arranged in an area of the frontal face of the fiber guide disc where a return action on the flow conditions in the fiber collecting trough can possibly occur only to a very slight degree or not at all. If necessary, the spinning rotor may also be provided with take-up vanes at its bottom surface.
In another preferred embodiment of the invention, one of the oppositely disposed surfaces of the spinning rotor and of the fiber collecting trough is provided with axially polarized annular magnets and the associated countersurface is made of electrically conductive material at least in the region of the annular magnets.
Due to the relative movement of the annular magnet with respect to the electrically conductive countersurfaces, eddy currents are produced therein, creating a force which carries along the fiber guide disc which is mounted without being provided with its own drive means. Advisably, the ring magnet is here disposed in the fiber guide disc since the centrifugal forces associated with the spinning rotor would give rise to structural difficulties.
The forces present between the spinning rotor and the fiber guide disc, and thus the range of speeds of the fiber guide disc, can be varied within certain limits by providing for adjustment of the distance between the bottom surface of the spinning rotor and the frontal face of the fiber guide disc.
In a further embodiment of the present invention, the rear surface of the fiber guide disc which faces away from the spinning rotor is disposed opposite a multipole, axially polarized annular magnet which is disposed in a component separate from the fiber guide disc, the fiber guide disc being made of electrically conductive material at least in the area of this "second magnet".
By means of the second magnet, which with a break-up roller arranged coaxially with respect to the spinning rotor may be disposed in the break-up roller, the speed of the fiber guide disc may be set within a range which is limited by the speed of the spinning rotor and that of the break-up roller.
In an arrangement where the break-up roller is offset with respect to the spinning rotor, the second magnet is advisably arranged to be at least radially stationary and is an electromagnet producing a variable field intensity. In this case the speed of the fiber guide disc can be varied over a wide range and the supply of current to the second magnet will not produce any difficulties.
An open-end spinning unit is conceivable in which the second magnet is disposed on the surface of the break-up roller facing the rear surface of the fiber guide disc, the break-up roller being arranged coaxially with the fiber guide disc.
This embodiment thus has a dual indirect drive in that the spinning rotor drives the fiber guide disc and the fiber guide disc drives the break-up roller.
The spinning unit provided with the second magnet may be further modified to provide for adjustment of the distance between the rear surface of the fiber guide disc and the second magnet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of an open-end spinning unit according to the invention with a break-up roller offset with respect to the spinning rotor and a fiber guide disc which is driven by magnetic forces.
FIG. 2 is a view similar to that of FIG. 1 of an open-end spinning unit according to the invention with a break-up roller arranged coaxially with the spinning rotor and a fiber guide disc with take-up vanes.
FIG. 3 is a view similar to that of FIG. 1 of an open-end spinning unit according to the invention with a break-up roller arranged coaxially with the spinning rotor and a fiber guide disc arranged therebetween and driven by magnetic forces from the spinning rotor, the rear surface of the fiber guide disc which faces away from the spinning rotor being disposed at a distance from and opposite an annular second magnet provided in the break-up roller.
FIG. 4 is a view similar to that of FIG. 1 of an open-end spinning unit similar to that of FIG. 3, but with an axially displaceable second magnet.
FIG. 5 is a view similar to that of FIG. 1 of an open-end spinning unit, but with an additional stationary electromagnet arranged to produce a variable field intensity.
FIG. 6 is a view similar to that of FIG. 2 of an open-end spinning unit, but with a magnet arranged in the break-up roller coaxially with the fiber guide disc, and without vanes on the rotor side of the fiber guide disc, so that the disc is driven by magnetic forces from the break-up roller.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The open-end spinning unit illustrated in FIG. 1 is provided with a break-up roller 2 which is axially offset with respect to the spinning rotor 1 and is driven in a known manner, for example by means of a tangential belt (not shown). Fiber material 3 to be processed is fed to the break-up roller 2 through an inlet channel 4, is broken up by the break-up roller, which is provided with a known combing arrangement 2', and is guided to the spinning rotor 1 through a fiber guide channel 6 in housing 5. The bottom surface 1' of the spinning rotor 1 is disposed opposite a fiber guide disc 7 which is supported in housing 5 by means of its shaft 7' through the intermediary of bearings 8. The rear section 7" of the fiber guide disc 7 is a defined section which engages into a correspondingly shaped circular recess 5' of housing 5.
In the region of its largest diameter, the fiber guide disc 7 is curved in the direction toward the bottom surface 1' as well as in the direction toward fiber collecting trough 1" of spinning rotor 1. The fiber guide disc 7 may, however, also be shaped differently.
The rotor 1 is made of electrically conductive material and the fiber guide disc 7 is provided on its frontal face 7'", which is directed toward the bottom surface 1' of the spinning rotor 1, with a multipole annular magnet 9 which produces eddy currents in the region of rotor 1 adjacent bottom surface 1', the eddy currents resulting in a force that causes rotation of the fiber guide disc 7.
The distance between the surfaces 1' and 7'" and the field intensity of the annular magnet 9 are advisably selected so that the rate of rotation of the fiber guide disc 7 is about 50 to 90% of the rate of rotation of the rotor 1. These relationships -- i.e. the presence of an almost identical peripheral speed in the area of the outer section of the fiber guide disc and of the spinning rotor -- result in the practically complete absence of air turbulence in the area of the fiber collecting trough 1".
The fibers 3' which have been broken up by break-up roller 2 are collected in the fiber collection trough 1" and are removed from there, for example by means of a pair of extraction rollers (not shown), through a stationary yarn extraction tube 10 as the finished yarn 11.
The yarn extraction tube 10 is disposed in the bore of shaft 12 of the spinning rotor 1; its inner end protrudes slightly beyond the bottom surface 1' of the spinning rotor.
The spinning rotor 1 is mounted via bearings 13 in a rotor housing 14 which is tightly connected with housing 5 and the interior of which is kept at a pressure below atmospheric by means of known suction devices.
The open-end spinning unit shown in FIG. 1 may also, without departing from the spirit of the invention, be designed so that the annular magnet 9 is disposed in the bottom surface 1' of the spinning rotor 1 and the frontal face 7'" of the fiber guide disc 7 is made of electrically conductive material at least in the area opposite the annular magnet.
The use of an indirect drive for the fiber guide disc 7 is not limited to open-end spinning units where the break-up roller 2 is eccentric to the spinning rotor.
FIG. 2 shows an open-end spinning unit in which the fiber guide disc 7 as well as the break-up roller 2 are coaxial with the spinning rotor 1.
The fiber guide disc 7 and the break-up roller 2 are here supported, via bearings 8 and 15, respectively, on a journal 16 which is held by means of a threaded section 16' in the threaded bore of a housing 17. The threaded journal 16 may be axially displaced by turning it; its position with respect to housing 17 is secured by a nut 18 and a spring disc 19 resting against housing 17.
The outwardly directed end of the break-up roller 2 is bolted or otherwise fixed to a belt pulley 20, into which engages, for example, a belt 21 which also passes around a suitable drive member (not shown).
The fiber guide disc 7 is provided on its frontal face 7'" with take-up, or fluid coupling, vanes 22 which are acted on by the air stream produced by the spinning rotor 1 to cause rotation of the fiber guide disc. This aerodynamic drive can be designed so that the fiber guide disc has practically the same rate of rotation as the spinning rotor driving it, which may also be provided with take-up vanes if required.
In the open-end spinning unit shown in FIG. 3 the fiber guide disc 7 is driven by the spinning rotor 1, in the manner described with reference to FIG. 1, by magnetic forces produced by an axially polarized annular magnet 9. The rear section 7" of the fiber guide disc is here designed as a defined section which engages into a circular recess 2" of the break-up roller 2 which is also coaxial with the spinning rotor 1.
A multipole annular magnet 23 is disposed in the frontal face of roller 2 defining recess 2" and facing the fiber guide disc and this magnet acts on the rear surface of section 7" opposite such frontal face and spaced at a distance therefrom. The portion of section 7" at the rear surface is made of electrically conductive material at least in the region adjacent the annular magnet 9.
Due to the electromagnetic interaction produced between parts 7 and 2 by the annular magnet 23, the break-up roller, which is supported on shaft 24 through the intermediary of bearings 15 and has no drive of its own, is driven by the fiber guide disc 7 which itself is driven indirectly; thus the break-up roller also requires no drive of its own. Between the fiber guide disc and the break-up roller as well as between the fiber guide disc and the spinning rotor there exists a difference in the rate of rotation, so that the rate of rotation of the fiber guide disc 7 lies between that of the break-up roller 2 and that of the spinning rotor 1.
In contrast to the previously described embodiments, in the embodiment of FIG. 3, the shaft 24 is stationarily connected with the housing 5 of the break-up roller via supports 24'; it may be provided with a bore through which the yarn formed in the area of the fiber collection trough 1" from the incoming fiber material is removed.
The open-end spinning unit shown schematically in FIG. 3 may be modified in such a manner that the break-up roller 2 which is provided with an annular magnet 23 is connected with its own drive unit, for example via a drive belt, so that its rotational speed can be independently controlled. Since the rotational speed of the break-up roller normally lies below that of the spinning rotor, the movement of the indirectly driven fiber guide disc is more or less inhibited by its interaction with the break-up roller. Varying the distance between the annular magnet 23 and the electrically conductive rear surface of the fiber guide disc 7 disposed opposite thereto or varying the field intensity of the annular magnet thus makes it possible to increase or decrease the rotational speed of the fiber guide disc, while the speed of roller 2 is maintained constant by its own drive unit.
In open-end spinning units where the break-up rollers 2 are disposed eccentrically to the spinning rotor 1, as in the case of the embodiment of FIG. 1, the rotational speed of the indirectly driven fiber guide disc 7 may be influenced by disposing its rearward section 7" opposite a radially stationary annular magnet; advisably, the annular magnet in this embodiment is not a permanent magnet but a multipole electromagnet where the magnetic field intensity can be influenced by varying the magnetization current in the magnetic windings. The supply of electrical energy produces no difficulties due to the stationary arrangement of the electromagnet, for example in the housing 5 of the break-up roller. The speed of the fiber guide disc can be varied over a continuous range or set between a maximum rate of revolution and zero.
In the open-end spinning unit of FIG. 4 the break-up roller 2 is also provided with a multipole permanent magnet 23 in the region of its frontal face 2" which is disposed opposite fiber guide disc 7.
The annular permanent magnet is here guided for axial movement in an annular recess 25 in break-up roller 2. The adjustment of the annular magnet is effected by rotating adjustment nuts 26 which are in engagement with adjustment rods 27 fastened to the rear surface 23' of the annular magnet 23.
The nuts 26 are supported by break-up roller 2, in recesses 29, by means of washers 28, and the axial position of the annular magnet 23 is set by rotating nuts 26 so as to move rods 27 axially against the force of prestressed compression spring elements 30 each interposed between the annular magnet 23 and the base of the annular recess 25.
By displacing the annular magnet 23 axially, the size of the air gap 31 between parts 23 and 7, and thus the driving force exerted by the fiber guide disc on the break-up roller, can be varied.
The embodiment shown in FIG. 4 thus permits adaptation of the mode of operation of the break-up roller to various fiber materials or the setting of the rate of rotation of the break-up roller.
The axial displaceability of the annular magnet 23 may of course also be achieved by other, known means.
The journal 24 on which the fiber guide disc 7 and the break-up roller 2 are supported, through the intermediary of bearings 8 and 15, respectively, is designed as a stationary thread extraction tube through which the finished yarn is withdrawn from the spinning turbine, for example by means of a pair of yarn extraction rollers.
The open-end spinning unit of FIG. 5 is similar to that of FIG. 1, but shows in addition a stationary electromagnet 32 which is inserted in housing 5 opposite and coaxial to fiber guide disc 7. Its magnetic force is variable by varying the supply of electrical energy via the wires 33. The part 7" of the fiber guide disc opposite to electromagnet 32 consists of electrically conductive material.
The driving force acting between magnet 9 and spinning rotor 1 can be counteracted by the above described additional electromagnet 32 of variable field intensity to produce a variable driving force and in consequence an adjustable rotational speed of the fiber guide disc.
FIG. 6 shows an open-end spinning unit similar to that of FIG. 2 but without vanes 22. In addition an axially or radially polarised permanent magnet 34 is inserted into the break-up roller 2 opposite and coaxial to the fiber guide disc 7, which consists of electrically conductive material.
The break-up roller 2 is mechanically driven by a belt 21 as described in FIG. 2. The fiber guide disc 7 is driven by the magnetic forces acting between magnet 34 and the material of fiber guide disc 7, which is radially disposed opposite magnet 34, if magnet is radially polarised, which is axially disposed opposite magnet 34, if magnet is axially polarised.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | In an open-end spinning unit for producing yarn from fiber material, the unit including a spinning rotor having a circumferential portion extending axially from one axial end face of the rotor to enclose a space in which such yarn is formed and which defines a fiber collection trough, and a fiber guide disc rotatably mounted coaxially of the rotor and having at least a portion disposed within such space, the guide disc is free of physical connection to any drive system and is mounted to be freely rotatable, and the unit further includes a force transmitting arrangement operatively connected between the rotor and the disc for causing the rotation of the rotor to induce rotation of the disc without physical contact between the rotor and the disc. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of waste drain connections for coupling the waste outlets of plumbing fixtures to the inlets of plumbing drains.
2. Description of the Prior Art
Waste drain connections for coupling the waste outlets of plumbing fixtures to plumbing drains typically found in the prior art rigidly couple the body of the compression ring and alignment yoke directly to the pipe employed to connect the waste outlet of a plumbing fixture, typically a toilet or water closet outlet, to the plumbing drain pipe. Such rigid and direct connections are exemplified by U.S. Pat. Nos. 1,988,298 (Burkett) and 2,208,199 (Sisk).
U.S. Pat. No. 1,988,298 employs an annular lead washer 28 disposed in between the exterior surface of the wall of the outlet pipe 12 and the interior surface of the wall of the pipe section 24 which is, in turn, coupled to the main outlet pipe. To form a fluid tight connection between these pipes, the lead washer 28 must be crushed so that it will be forced tightly against the pipe 12 and the threads 25 of pipe 24.
With regards to U.S. Pat. No. 2,208,199, a simple and direct threaded coupling is employed to effectuate a similar fluid tight seal between the coupling pipe and the main outlet pipe.
The major problems associated with such fluid tight waste connections are high cost, time-consuming installation of such joints since such installations are performed in the field by "wiping". Further, such connections are rigid and because of this rigidity misalignment poses a number of problems. Should radial axial misalignment exist prior to installation, such misalignment will not permit the formation of a fluid tight seal between the pipes. If the misalignment occurs following installation due to the relative movement between the pipes, loss of the fluid tight seal will result either because of the breakage of either or both pipes or because of seal breakage or causing the seal material, usually lead, to be permanently upset, thereby creating a fluid passageway between the seal and the pipes.
Similar problems are associated with the prior art arrangements disclosed in U.S. Pat. Nos. 1,490,805 (Divekey), 1,706,285 (Frye), and 3,409,918 (Gaddy).
In reviewing such examples, it may be readily seen that such assemblies are relatively complex, expensive to construct and require a relatively lengthy period of time to install.
SUMMARY OF THE INVENTION AND OBJECTS
Fundamentally, the present invention comprises a waste drain connection for coupling the waste outlet of a plumbing fixture having a receptacle for a fluid-sealing gasket thereabout to a plumbing drain pipe including a fluid-sealing member having a sleeve portion adapted for intimate fluid-sealing about the plumbing drain pipe and an outwardly-extending flange forming a gasket about one end thereof and a sleeve and gasket compression member for containing the sleeve and for compressively urging the sleeve into greater intimate contact with the plumbing drain pipe to ensure a fluid sealing relationship therebetween and for compressively urging the gasket into intimate contact with the gasket receptacle to effectuate a fluid sealing relationship therebetween.
An object of the present invention is to provide an inexpensive, labor-saving apparatus for effectuating the connection of the waste outlet of a plumbing fixture, such as a toilet, to a plumbing drain pipe.
Another important and primary object of the instant invention is to provide a slip joint type of plumbing pipe drain connection which allows for a relatively substantial longtitudinal variation between the waste outlet of the plumbing fixture and the plumbing drain pipe.
A yet still further and important object of the present invention is to provide a waste drain connection which permits a rather substantial amount of angular misalignment between the waste outlet of a plumbing fixture and the plumbing drain pipe linked by the present invention herein.
Another primary and significant object of the invention is to provide a waste drain connection which substantially eliminates the problems inherent in rigid joint waste drain connections.
A yet still further object of the present invention is to provide a waste drain connection which assures a permanent gas and water tight seal even under adverse conditions of pipe movement and field conditions such as axial and radial misalignment.
Other characteristics, advantages and objects of this invention can be more readily appreciated from the following description and appended claims. When taken in conjunction with the accompanying drawings, this description forms a part of the specification wherein like references and characters designate corresponding parts in several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded assembly view of the various elements forming the present invention.
FIG. 2 is a transverse sectional view of a portion of the present invention shown assembled.
FIG. 3 is a transverse sectional view of a portion of the present invention shown assembled and compressively engaged with the sealing member to ensure a fluid sealing relationship between the waste outlet of the plumbing fixture and the plumbing drain pipe.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With continued reference to the drawings, and, in particular, now to FIG. 1, the present invention is generally indicated at 10, comprising a fluid sealing member, generally indicated at 11, and a sleeve and gasket compression member, generally indicated at 12. As is clearly shown and illustrated in this exploded assembly view, the sleeve and gasket compression member 12 is adapted to be arranged about the body of the fluid sealing member 11.
The fluid sealing member 11 is characterized by numerous and diverse functional portions which are further pointed out and described herein. The body of the fluid sealing member 11 is preferrably formed of an elastomeric material, such as 50 shore hardness Neoprene, and basically comprises two portions: a sleeve portion 13 and a flange portion 14 adapted to function, as hereinafterwards described, as a gasket. While the inside diametered portion of the fluid sealing member 11 has a relatively constant and uniform cross-section, the outside diametered portion of the fluid sealing member 11 does not have such a relatively uniform and constant cross-section. The outside diameter of the fluid sealing member 11 is divided into two basic portions, one of which is larger than the other. The largest diametered portion defines the flange portion 14 which functions as a fluid-sealing gasket. A pair of outwardly-projecting rings 40 are cast into the face of the flange portion 14 act to improve the fluid-sealing surface thereof when compressively engaged with the gasket receptacle as hereinafterwards described. The smaller outside diametered portion defines the sleeve portion 13 of the fluid sealing member 11. The inside diameter of the fluid sealing member, while being relatively uniform, is, nevertheless, characterized by the following sections. The rim 15 of the flange portion 14, in this particular embodiment of the invention, adjacent the inside diameter thereof, is chamfered at 16. The purpose of this chamfered portion 16 will be described as the discussion of the invention proceeds herein.
The opposite rim 17 is similarly beveled at 18. About the inside diametered portion adjacent to the flange portion 14 is a first annular groove 19 and a second shallower annular groove 43, the purposes of which will become readily known and understood as the disclosure of the invention further unfolds hereinafterwards. A pair of rings 42 ringing the annular raised portion 43 cast into the sleeve portion 13 act to improve the fluid sealing surface thereof when compressively engaged as hereinafterwards described.
The sleeve and gasket compression member 12 includes an annular groove 20 about the edge 21 of the rim 22 of the member 12 facing the flange portion 14 which forms the face which functions as the gasket compressing portion of the member 12. The inside diameter of the member 12 is slightly larger than the smaller outside diametered portion of the fluid sealing member 11 which defines the sleeve portion 13 thereof to allow it to fit over the sleeve portion 13 of the fluid sealing member 11. The inside diametered portion of the member 12 adjacent to the other rim 23 of the member 12 is uniformly reduced or tapered at 24. The purpose of this taper 24 will become readily apparent later in the discussion. Ringing the outside of the member 12 is an outwardly extending ring 25. The ring 25 has at least two apertures 26 therein through which pass a pair of threaded rods 27. Generally, it is preferred that such apertures are disposed on opposite sides of the member 12.
Turning our attention now to FIG. 2, the present invention is depicted in an installed configuration. The plumbing fixture is partially and representatively shown in section at 27. The waste outlet of the plumbing fixture is identified at 28, the waste outlet 28 being the outlet from which the fluid and solid effluent is expelled from the plumbing fixture 27. As illustrated, the waste outlet 28 has a rearwardly projecting annular rim forming a pipe which is virtually identical to plumbing drain pipe 29. The plumbing drain pipe 29 is slideably coupled with the sleeve portion 13 of the fluid sealing member 12 along the inside diametered portion thereof. The plumbing drain pipe 29 is then positioned in abutting, edge-to-edge relationship with the rim of the waste outlet 28. In so doing, the joint formed at 50 presents a smooth, uninterrupted inside surface to minimize the resistance thereof to the passage of the effluent thereover. Such is termed in the plumbing trade a "sanitary pipe connection".
The flange portion 14 is disposed in the gasket receptacle 30 having a U-shaped cross-section with an outer sidewall 33 which is longer than the inner sidewall 34 and which is annularly disposed about the waste outlet 28 of the plumbing fixture 27 and faces rearwardly thereof. The threaded rods 27 (only one is shown in FIG. 2) and threadably secured to the plumbing fixture 27 via the threaded receptacles 31 (only one is shown) and the body of the rods 27 are passed through the apertures 26 in the ring 25. Nuts 32 are used to anchor the ring 25 of the member 12 to the plumbing fixture 27 and to adjustably move the rim 22 containing the annular groove 20 against the flange portion 14 which forms the gasket and to compress it as shown and depicted in FIG. 3. As the flange 14 is compressed it may be readily seen that the annular groove 20 forms a ridged surface which prevents radial slippage of the gasket thereby formed and which effectively captures the gasket by compressively holding it within the gasket receptacle 30. The chamfered portion 16 is now seen as permitting engagement with the edge of the smaller sidewall 34 with the fluid sealing member 11 and permits the elastomeric material to be moved into the void previously existing prior to compressive deformation between the chamfered portion 16 and the gasket receptacle 30. However, it should be clearly understood and noted at this time that the chamfered portion 16 is not an essential part of this invention and should not be construed as being a limitation thereon in any way. A similar function and event occurs relative to the annular groove 19 and that portion of the plumbing drain pipe 29 which is coextensive therewith.
As the flange 14 is compressed, the tapered portion 24 about the inside diametered portion of the member 12 is also drawn towards the gasket receptacle 30. Due to this effectively reduced diametered portion, the rim 17 of the sleeve portion 13 acts to compressively urge the sleeve into more intimate fluid sealing relationship with the plumbing drain pipe 29 and the sleeve portion 13 of the fluid sealing member 11.
It should be noted at this time that the compression desired is approximately twenty-five percent of the original uncompressed thickness of the gasket portion 14. To prevent over-compression of the flange portion 14 and possible breakage and subsequent leakage of fluid therebetween, the edge of the outer sidewall 33 of the gasket receptacle 30 serves as a physical stop to limit the movement of the ring 25, and, hence, the entire sleeve and gasket compression member 12, to prevent such over-compression of the fluid sealing member 11.
The result is an effective waste drain connection which is capable of radial, axial and angular misalignment over a relatively wide range as compared to those waste connections used hereinbefore.
The invention and its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangement hereinbefore described being merely by way of example, and I do not wish to be restricted to the specific form shown or uses mentioned, except as defined in the accompanying claims. | A waste drain connection for coupling the waste outlet of a plumbing fixture having a receptacle for a fluid-sealing gasket thereabout to a plumbing drain pipe including a fluid-sealing member having a sleeve portion adapted for intimate fluid-sealing about the plumbing drain pipe and an outwardly-extending flange forming a gasket about one end thereof and a sleeve and gasket compression member for containing the sleeve and for compressively urging the sleeve into greater intimate contact with the plumbing drain pipe to ensure a fluid sealing relationship therebetween and for compressively urging the gasket into intimate contact with the gasket receptacle to effectuate a fluid sealing relationship therebetween. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a composition for forming a piezoelectric film, a method for producing a piezoelectric film, and an ink jet recording head provided with such piezoelectric element.
[0003] 2. Related Background Art
[0004] A piezoelectric element is constituted of piezoelectric crystalline ferroelectric or paraelectric ceramics. The piezoelectric ceramics generally have a two-component system principally constituted of lead zirconate-titanate (hereinafter called “PZT”), or a three-component system in which a third component is added to PZT of the two-component system. A ferroelectric substance employing the two-component PZT is described in Applied Physics Letters 1991 , vol. 58, No. 11, pp1161-1163. For forming a piezoelectric thin film of such metal oxide type, there are known a sputtering method, an MOCVD method and a sol-gel method.
[0005] There is also disclosed an ink jet printing head utilizing a piezoelectric element employing a film formed by the sol-gel method. For example, Japanese Patent Applications Laid-open Nos. H9-92897, H10-139594 and H10-290035 disclose a method forming a piezoelectric thin film of a piezoelectric element usable for an ink jet printing head, by the sol-gel method, by coating a sol containing a piezoelectric material plural times on a lower electrode and repeating a heating process.
[0006] However, by simply dissolving an ordinary metal complex or a metal salt of an organic acid in a solvent as a composition for forming a piezoelectric film by the sol-gel method, it is difficult to obtain a uniform composition since the organometallic compounds having respectively different hydrolyzing rates respectively form single metal oxides. Also at sintering process, a complex is formed by a solid-phase reaction of such metal oxides, but it is difficult to obtain a uniformly controlled composition in the thin film because of a difference in the volatility thereof. Also at the film formation, there is often formed a film of a fine powder state, tending to generate an electrical conductivity.
[0007] Against these issues it is known to add a stabilizer for controlling a rapid hydrolysis, and such method is considered to contribute to the stabilization of the coating liquid and the stabilization of the film formation.
[0008] As the stabilizer, there have been utilized a diketone, a ketoacid, a lower alkyl ester of such ketoacid, an oxyacid, a lower alkyl ester of such oxyacid, an oxyketone, an α-amino acid, an alkanolamine etc. Such stabilizer stabilizes a metal alkoxide and/or a metal salt by chelating, thereby reducing the rate of hydrolysis reaction. For example an alkoxide of Ti or Zr is reacted with acetylacetone to reduce the reaction rate of hydrolysis, thereby obtaining a dense film.
[0009] However, the use of such stabilizer may still be unable to provide a satisfactory result because a conversion from an alkoxide to an oxide is incomplete to generate an incompletely dense film composed of fine particles, thereby leading to a fluctuation in the composition by a loss of a more volatile metal component or to a fluctuation in the piezoelectric property. Also a film formation with the above-mentioned stabilizer result in uneven sizes of the particles constituting the thin film. In the thin film with such uneven surface state, the piezoelectric property may become uneven depending on the location.
[0010] Also from the standpoint of the manufacture of a piezoelectric element, it is considered more efficient to obtain a larger film thickness in a single layer to be formed, and necessary to have measures for attaining such thickness. Also for use as an actuator, there is required a dense film showing uniform characteristics as a piezoelectric element on the film surface and being excellent in the durability. Also a formation of a thick film results in defects such as a cracking in the film, and is associated with insufficient characteristics as an actuator. Also a conventional method for producing a composition for forming the piezoelectric film, the composition may show a precipitate generation by a polymerization reaction in the liquid in case of a prolonged storage, thus not being usable in stable manner over a prolonged period.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a composition for forming a piezoelectric film showing little unevenness in the surface state and capable of providing satisfactory piezoelectric characteristics, a producing method for such piezoelectric film, a piezoelectric element and an ink jet recording head.
[0012] The present invention employs, as a stabilizer, at least one of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane. It stabilizes a metal alkoxide and/or a metal salt by an electron donation from 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5 -diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane. At the same time, it is intended to vary the reactivity and solubility of metal alkoxide and/or metal salt, thereby controlling a rate of hydrolysis at sol synthesis, a rate of condensation-polymerization reaction and a structure of the resulting reaction product. It is thus found possible to attain an improvement in the characteristics of a piezoelectric element, an improvement in the storability of the composition for forming the piezoelectric film and an improvement in the performance of the ink jet recording head, thereby arriving at the present invention.
[0013] The piezoelectric film forming composition of the present invention is a composition for forming a piezoelectric film containing a dispersoid obtained from an organometallic compound for forming a piezoelectric film, featured in containing, as a stabilizer in the solution, at least one of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane.
[0014] The piezoelectric film forming composition of the present invention is featured in having a content of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane within a range from 0.005 to 5.0 times in moles with respect to a number of moles of all metallic atoms in the piezoelectric film forming composition.
[0015] Also the piezoelectric film forming composition of the present invention is featured in containing, at least one of elements Pb, La, Zr and Ti as a constituent element.
[0016] A producing method of the present invention for producing a piezoelectric element is featured by repeating steps of coating the aforementioned piezoelectric film forming composition on a heat-resistant substrate and executing heating in the air, in an oxidizing atmosphere or in a vapor-containing atmosphere until a film of a desired thickness is obtained, and sintering the film at or above a crystallizing temperature during or after the heating at least in the final step.
[0017] An ink jet recording head of the present invention is an ink jet recording head provided with a piezoelectric element produced by the aforementioned producing method for the piezoelectric film, featured in including a pressure chamber substrate on which a pressure chamber is formed, a vibration plate provided on a surface of the pressure chamber, and the piezoelectric element provided in a position of the vibration plate corresponding to the pressure chamber and so constructed as to cause a volume change in the pressure chamber.
[0018] The present invention can provide a composition for forming a piezoelectric film showing little unevenness in the surface state and capable of providing satisfactory piezoelectric property even in a thick film formation, a method for forming such piezoelectric film, a piezoelectric element and an ink jet recording head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 is a cross-sectional view schematically showing a piezoelectric element of the present invention;
[0020] [0020]FIG. 2 is a cross-sectional view schematically showing the configuration of an ink jet printing head employing a piezoelectric element of the present invention as an actuator;
[0021] [0021]FIG. 3 is a perspective view schematically showing a substrate employed in Examples 1 to 13 and Comparative Examples 1 to 3;
[0022] [0022]FIG. 4 is a cross-sectional view schematically showing a substrate employed in Examples 1 to 13 and Comparative Examples 1 to 3;
[0023] [0023]FIG. 5 is a cross-sectional view schematically showing a piezoelectric element prepared in Examples 1 to 13 and Comparative Examples 1 to 3;
[0024] [0024]FIG. 6 is a cross-sectional view schematically showing a head employed in an evaluation of the ink jet recording head;
[0025] [0025]FIG. 7 is a perspective view schematically showing a head employed in an evaluation of the ink jet recording head; and
[0026] [0026]FIG. 8 is a chart showing hysteresis curves of Example 1 and Comparative Example 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] In the following, there will be explained embodiments for executing the present invention.
[0028] [0028]FIG. 1 is a view showing the configuration of an embodiment of the piezoelectric element of the present invention, wherein shown is a substrate 1 .
[0029] There is preferably employed a semiconductor substrate such as of silicon (Si) or tungsten (W), but there can also be employed a ceramic material such as zirconia, alumina or silica. Also there may be formed an oxide layer or a nitride layer as an outermost surface.
[0030] Referring to FIG. 1, lower and upper electrodes 2 , 4 in the present invention are formed by a conductive layer of about 5 to 500 nm. More specifically, there is employed one or more of metals such as Ti, Pt, Ta, Ir, Sr, In, Sn, Au, Al, Fe, Cr, Ni etc. and oxides thereof in a laminar form.
[0031] Such metal or oxide may be formed on the substrate by coating and sintering by a sol-gel method, or by sputtering or evaporation. Also each of the lower electrode and the upper electrode may be patterned in a desired shape.
[0032] Referring to FIG. 1, a piezoelectric film 3 is prepared by a sol-gel method from a substance containing, as a constituent element, at least one of elements Pb, La, Zr and Ti. More specifically, it can be obtained by dissolving an alkoxide and/or a metal salt of Pb, La, Zr, Ti etc. in a solvent, then adding water for executing a hydrolysis to obtain a coating liquid, coating and drying such coating liquid on a substrate and executing a sintering in a subsequent heat treatment step.
[0033] In addition to Pb, La, Zr and Ti, an element of a trace amount may be used for doping. Specific examples include Ca, Sr, Ba, Sn, Th, Y, Sm, Ce, Bi, Sb, Nb, Ta, W, Mo, Cr, Co, Ni, Fe, Cu, Si, Ge, Sc, Mg, Mn etc. Its content is 0.05 or less in atomic fraction of the metal atoms in a general formula Pb l-x La x (Zr y Ti 1-y )O 3 (wherein 0 ≦x<1, 0≦y≦1).
[0034] Organometallic compounds to be employed as raw materials of metal components of the piezoelectric film are dispersed together in a suitable organic solvent to prepare a raw material sol containing a precursor of a complex organic metal oxide (oxide containing two or more metals) which is a piezoelectric material. The solvent for the sol is selected suitably from various known solvents in consideration of the dispersion property and the coating property.
[0035] Examples of the solvent include an alcoholic solvent such as methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol, or t-butanol; an ether solvent such as tetrahydrofuran or 1,4-dioxane; a cellosolve solvent such as 2-methoxyethanol, 2-ethoxyethanol, or 1-methoxy-2-propanol; a polyhydric alcohol such as diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, or diethylene glycol monobutyl ether acetate; an amide solvent such as N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone; and a nitrile solvent such as acetonitrile. Among these, there is preferred an alcoholic solvent. An amount of the solvent employed in the sol-gel method of the present invention is usually 5 to 200 times in moles with respect to metal alkoxide, preferably 10 to 100 times in moles. An excessively large amount of the solvent renders gellation difficult, while an excessively small amount causes a significant heat generation in hydrolysis.
[0036] Examples of alkoxide of lead include lead 2-ethoxyethoxide, lead methoxide, lead ethoxide, lead n-propoxide, lead i-propoxide, lead n-butoxide, lead i-butoxide, lead t-butoxide and other alkoxide and alkyl substituted compounds thereof.
[0037] It is also possible to employ an inorganic salt compound of Pb, more specifically a chloride, a nitrate, a phosphate or a sulfate, or an organic salt compound for example a carboxylate such as a formate, an acetate, a propionate, an oxalate, a succinate or a malate, a hydroxycarboxylate, an acetylacetonate complex, by mixing with a solvent to in situ synthesize an alkoxide. La, Mg, Zr, Ti or Nb may also be employed in an alkoxide compound or an inorganic salt in a similar manner. An alkoxide solution or an inorganic salt of Pb, La, Mg, Zr, Ti or Nb is dissolved in the aforementioned solvent and hydrolyzed to obtain a polymer compound, thereby obtaining a coating liquid for a piezoelectric film.
[0038] The organometallic compound to be employed as a raw material can be, in addition to a compound containing a metal as explained above, a complex organometallic compound containing two or more metals. Examples of such complex organometallic compound include PbO 2 [Ti(OC 3 H 7 ) 3 ] 2 and PbO 2 [Zr(OC 4 H 9 ) 3 ] 2 . In the present invention, a term “an organometallic compound” is used in a wide sense indicating a compound including a metal and an organic group, not in a narrow sense indicating compound containing a carbon-metal bond.
[0039] The charging of the aforementioned metals, for example in case of employing Pb, La, Zr and Ti, can be made by Pb (l-x )La x (Zr y Ti 1-y )O 3 (wherein 0≦x<1, 0≦y≦1), but, since Pb is lost in the course of sintering at the film formation, it is preferred to increase the amount of Pb in advance at the preparation of the coating liquid. More specifically, in Pb (l-x) La X (Zr y Ti l-y )O 3 (wherein 0≦x<1, 0≦y≦1), it is possible to increase the molar ratio of Pb by 5 to 30%.
[0040] Then a stabilizer is added to the mixed solution to achieve stabilization. This is to cause a mild polymerization of a metal-oxygen-metal bond as a whole. However, a supply of the stabilizer in a large amount may hinder an appropriate hydrolysis, or may cause precipitation because of solubility.
[0041] In the present invention, in the organometallic compound solution for the piezoelectric film forming composition, there is added, as a stabilizer, at least one of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane. A content of the stabilizer in the organometallic compound solution is within a range from 0.005 to 5.0 times in moles with respect to the moles of total metal atoms, preferably 0.05 to 2.5 times in moles, since an excessively small content cannot provide a sufficient improving effect by such addition while an excessively large content increases the viscosity thereby deteriorating the film forming property. 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane may be employed in a combination of plural kinds. Also they may be employed as a salt combined with an acid. Specific examples include a formic acid salt and an octylic acid salt. It is also possible to employ, in combination, another known stabilizer for example a β-diketone (such as acetylacetone, heptafluorobutanoyl pivaroyl methane, dipivaloylmethane, trifluoroacetylacetone, or benzoylacetone), a ketoacid (such as acetacetic acid, propionylacetic acid, or benzoylacetic acid), a lower alkyl (such as ethyl, propyl or butyl) ester of such ketoacid, an oxyacid (such as lactic acid, glycolic acid, α-oxybutyric acid or salicylic acid), a lower alkyl ester of such oxyacid, an oxyketone (such as diacetone alcohol or acetoin), an α-amino acid (such as glycine or alanine), or an alkanolamine (such as diethanolamine, triethanolamine or monoethanolamine).
[0042] An amount of the stabilizer to be employed in the present invention, in case at least one of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane is used in combination with the above-mentioned prior stabilizer, is usually from 0.05 to 5 times in moles with respect to the number of moles of the total metal atoms, preferably 0.1 to 1.5 times in moles.
[0043] In such case, an amount of the prior stabilizer to be used in combination is usually from 0.01 to 20 times in moles with respect to 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, or 1,4-diazabicyclo[2.2.2]octane, preferably 0.05 to 10 times in moles.
[0044] For a hydrolysis of a solution containing a metal alkoxide and/or a metal salt, there is employed for example water in an amount of 0.05 to 30 times in moles of metal alkoxide and/or metal salt, preferably 0.5 to 15 times in moles. For such hydrolysis, there may be employed an acid catalyst and/or a base catalyst. A preferred acid catalyst is a metal salt, a halide, a mineral acid such as sulfuric acid, nitric acid or hydrochloric acid, or an organic acid such as acetic acid. Also as a base catalyst, there is often employed ammonia which can be easily eliminated by drying and sintering.
[0045] The rate of the hydrolysis reaction can be controlled for example by a kind of metal alkoxide and/or metal salt, a kind of solvent, a water concentration with respect to metal alkoxide and/or metal salt, a concentration of metal alkoxide and/or metal salt, and a stabilization by chelating of the catalyst, metal alkoxide and/or metal salt.
[0046] After the solution of the above-mentioned metal composition is hydrolyzed, a solvent of a boiling point equal to or lower than 100° C. is completely eliminated, and a solvent having a boiling point equal to or higher than 100° C. is added in an amount of 50% or higher. Examples of the employable solvent include a cellosolve such as 1-methoxy-2-propanol, 2-ethoxyethanol, or 3-methoxy-3-methylbutanol; a polyhydric alcohol such as diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether or diethylene glycol monobutyl ether acetate; and an incense oil such as terpineol, pine oil or lavender oil. There is preferred a cellosolve solvent. It is also possible to use a cellulose derivative such as ethyl cellulose or hydroxypropyl cellulose, a polymer resin such as polyvinyl alcohol, polyvinylpyrrolidone or a polyvinylpyrrolidone derivative, rosin or a rosin derivative, for a purpose of improving the coating property.
[0047] Thereafter, a stabilizer is further added in a predetermined amount, thereby suppressing the hydrolysis rate and the polymerization-condensation speed of the raw material solution and improving the stability in time thereof, without affecting the improving effect for the coating property and the surface state.
[0048] The aforementioned coating liquid is coated and dried on a lower electrode formed on a substrate. The coating can be made by a known coating method such as spin coating, dip coating, bar coating or spray coating. A relative humidity in such operation is preferably 60% or lower. A relative humidity exceeding 60% is undesirable since the coating liquid on the substrate may show a fast hydrolysis, thus providing a precitate.
[0049] A thickness per a layer after drying is not particularly restricted, but is preferably from 0.01 to 5 μm. Also a total film thickness is preferably about from 1 to 30 μm.
[0050] The drying is executed at a temperature equal to or lower than 200° C. This operation is conducted in the presence of a gas with a relative humidity of 10 to 70% at 25° C. A humidity at or above 70% is undesirable because the coating liquid on the substrate causes a fast hydrolysis thereby leading to a crack formation. On the other hand, with a humidity at or below 10%, the hydrolysis does not proceed at all whereby a temperature of a sintering process to be explained later undesirably increases. For such drying, there can be utilized a drying machine, a dryer, a hot plate, a tubular oven or an electric oven. Also a gas having a relative humidity of 10 to 70% at 25° C. can be obtained by bubbling a desired gas in water. It is also possible to introduce a gas conditioned with a humidifier or the like.
[0051] Then a sintering is executed within a range from 200 to 500° C. This operation is conducted in the presence of a gas with a relative humidity of 70 to 99% at 25° C. A humidity at or below 70% is undesirable because the hydrolysis does not proceed. For such sintering, there can be utilized a drying machine, a dryer, a hot plate, a tubular oven or an electric oven. Also a gas having a relative humidity of 70 to 99% at 25° C. can be obtained by bubbling a desired gas in water. It is also possible to introduce a gas conditioned with a humidifier or the like.
[0052] Then a sintering is executed within a range from 500 to 800° C. This operation is conducted in the presence of a gas with a relative humidity of 70 to 99% at 25° C. A humidity at or below 70% is undesirable because the hydrolysis does not proceed. For such sintering, there can be utilized a tubular oven or an electric oven. Also a gas having a relative humidity of 70 to 99% at 25° C. can be obtained by bubbling a desired gas in water. It is also possible to introduce a gas conditioned with a humidifier or the like.
[0053] The aforementioned gas containing moisture preferably flows at a constant speed on the coated surface. A stagnation of the gas is undesirable as the hydrolysis of the coating liquid is hindered. A preferred flow speed on the substrate is from 0.5 to 50 cm/sec. However, a stagnation can be tolerated in case the substrate has a small region and the moisture-containing gas is present in a large excess.
[0054] A thickness, after the sintering, per layer formed by the coating liquid is not particularly restricted but is selected within a range of 0.01 to 1 μm, preferably 0.02 to 0.9 μm in consideration of working efficiency. The above-described operation may be repeated to obtain a piezoelectric film of an arbitrary thickness. The drying step has to be executed for each layer, but the sintering and the sintering may be executed for each layer or collectively for several layers. Also the sintering may be executed only at last.
[0055] A gas present on the substrate surface from the drying step to the sintering step is preferably an oxygen-containing atmosphere, preferably with an oxygen concentration of 20 to 100%. With a concentration lower than 20%, the sintering does not proceed and cannot provide a perovskite structure.
[0056] Also the sintering may be executed with stepwise temperature increases. Such sintering allows to eliminate organic components almost completely, thereby providing a piezoelectric film of a dense structure. FIG. 2, showing an embodiment of the present invention, is a schematic partial magnified view of an ink jet printing head in which a piezoelectric element is employed as an actuator. The printing head has a basic configuration same as that in the prior technology, and is constituted of a head base 5 , a vibrating plate 7 and a piezoelectric element. The head base 5 is provided with a plurality of ink nozzles (not shown) for discharging ink, a plurality of ink paths (not shown) respectively communicating with the ink nozzles, and a plurality of ink chambers 6 respectively communicating with the ink paths, and the vibrating plate 7 is so mounted as to cover an entire upper surface of the head base 5 , whereby the vibrating plate 7 closes upper apertures of all the ink chambers 6 of the head base 5 . On the vibrating plate 7 , piezoelectric elements 8 for providing the vibrating plate 7 with a vibrating force are formed in positioned respectively corresponding to the ink chambers 6 . An electric power source 9 controls the plural piezoelectric elements 8 and applies a voltage to a desired piezoelectric element 8 to induce a displacement therein, thereby causing a vibration in the vibrating plate 7 in a corresponding portion. Thus an ink chamber 6 , in a portion corresponding to the vibration of the vibrating plate 7 , shows a change in a volume, whereby an ink is pushed out from the ink nozzle through the ink path to achieving a printing.
EXAMPLES
[0057] In the following, the present invention will be clarified in more details by examples, but the present invention is not limited by such examples unless the scope of the invention is exceeded.
Preparation Examples 1-11 of Coating Liquid
[0058] In these examples, coating liquids with a metal composition represented by Pb l+x-y La y Zr 0.52 Ti 0.48 (in which 0≦x≦0.3, 0≦y≦1) as shown in Table 1, for forming a piezoelectric film, were prepared in the following manner.
[0059] A lead acetate hydrate (Pb) and a lanthanum acetate hydrate (La) were mixed and dehydrated, and at least compound selected from 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, 1,4-diazabicyclo[2.2.2]octane, a formate salt of 1,8-diazabicyclo[5.4.0]-7-undecene, and an octylate salt of 1,8-diazabicyclo[5.4.0]-7-undecene, and 1-methoxy-2-propanol (solvent 1 ) were mixed thereto and reacted. Hereinafter, 1,8-diazabicyclo[5.4.0]-7-undecene is abbreviated as DBU, 1,5-diazabicyclo[4.3.0]non-5-ene as DBN and 1,4-diazabicyclo[2.2.2]octane as DABCO. Thereafter, 0.52 moles of zirconia tetra-n-butoxide and 0.48 moles of titanium n-butoxide were added and reacted under further heating whereby the raw material metal compounds were mutually complexed. Then water and ethanol (solvent 2 ) were added to execute a hydrolysis reaction. In this operation there was added acetic acid or acetylacetone. Also polyvinylpyrrolidone K-30 (PVP) was added as a film formation assisting agent in certain examples (Examples 5, 6, 7). Thereafter, the solvents having a boiling point of 100° C. or lower were completely eliminated by a rotary evaporator, and diethylene glycol monoethyl ether (solvent 3 ) was so added that the metal oxide concentration converted into the foregoing formula became 10 wt. %.
TABLE 1 acetic acetyl Prod. Pb La DBU DBN DABO solvent 1 water solvent 2 acid acetone PVP solvent 3 Ex (mol) (mol) (mol) (mol) (mol) (mol) (mol) (mol) (mol) (ml) (mol) (mol) 1 1.03 0 7.0 0 0 16 5.0 10 7.0 0 0 11 2 1.05 0.01 0.1 0 0 13 9.0 7.0 0 1.5 0 16 3 1.15 0 0.8 0 0 10 7.0 7.0 3.0 0.5 0 15 4 1.20 0 2.0 0 0 10 4.5 5.0 4.0 0.7 0 12 5 1.17 0.01 1.2 0 0 12 6.0 15.0 7.5 1.2 0.01 12 6 1.06 0 0.3 0 0 10 10 8.0 0 1.0 0.6 13 7 1.04 0 10.0 0 0 18 4.0 10 5.0 0 0.01 13 8 1.03 0 0 0.8 0 16 5.0 10 7.0 0 0 11 9 1.05 0 0 0 0.1 20 9.0 7.0 0 1.5 0 16 10 1.15 0 1.2 0 0 10 7.0 7.0 3.0 0.5 0 15 (formate) 11 1.10 0 2.0 0 0 10 4.5 5.0 4.0 0.7 0 12 (octylate)
Comparative Preparation Example 1
[0060] A coating liquid for forming piezoelectric film was prepared in the same manner as in the Preparation Example 2, except that DBU was replaced by diisopropylethylamine.
Comparative Preparation Example 2
[0061] A coating liquid for forming piezoelectric film was prepared in the same manner as in the Preparation Example 5, except that a lead acetate hydrate (Pb) and a lanthanum acetate hydrate (La) were mixed and dehydrated, then zirconia isopropoxide and titanium isopropoxide were added and reacted, and diaminoethanol was added instead of DBU.
Comparative Preparation Example 3
[0062] A coating liquid for forming piezoelectric film was prepared in the same manner as in the Preparation Example 2, except that the synthesis was conducted without adding DBU. This coating liquid, when let to stand, showed precipitation of white crystals.
Examples 1-9
[0063] On a Zirconia substrate (3 cm square) having a partial recess on a rear surface as shown in FIGS. 3 and 4, each of the coating liquids obtained in the Preparation Examples 1, 3, 4, 6, 7, 8 and 9 was spin coated and was dried for 5 minutes at 100° C. in the air having a relative humidity of 35% at 25° C. (drying step) It was then treated for 5 minutes at 400° C. in a tubular oven of a diameter of 5 cm and a length of 100 cm (including a heater portion of 30 cm), under a gas flow containing oxygen by 30% and nitrogen by 70% and having a relative humidity of 80% at 25° C., with a flow speed of 20 cm/sec (sintering step), and was heat treated for 5 minutes at 650° C. in the same atmosphere (sintering step). After the coating and the heating were repeated three times, a sintering was executed for 40 minutes at 700° C. in the above-mentioned tubular oven and in a gaseous atmosphere containing oxygen by 30% and nitrogen by 70% and having a relative humidity of 75% at 25° C. (sintering step), followed by a cooling to the room temperature in the same humidity atmosphere (cooling step) to obtain a piezoelectric element of the present invention (FIG. 5). An analysis of an intermediate portion of the piezoelectric film provided a metal composition Pb 1.0 Zr 0.52 Ti 0.48.
[0064] The film thickness after coating and sintering three times was as follows.
TABLE 2 Preparation Examples of Film thickness Example coating liquid (μm) 1 1 1.45 2 3 0.98 3 4 1.26 4 6 1.47 5 7 1.58 6 8 1.60 7 9 0.77 8 10 1.43 9 11 1.52
Examples 10-11
[0065] On a substrate similar to that in the Examples 1-4, each of the coating liquids obtained in the Preparation Examples 2 and 5 was spin coated and was dried for 5 minutes at 100° C. in the air having a relative humidity of 50% at 25° C. (drying step). It was then heated for 20 minutes at 300° C. in a tubular oven of a diameter of 5 cm and a length of 100 cm (including a heater portion of 30 cm), in a gaseous atmosphere containing oxygen by 30% and nitrogen by 70% and having a relative humidity of 90% at 25° C. (sintering step). After the coating and the heating were repeated three times, a sintering was executed for 40 minutes at 750° C. in the above-mentioned tubular oven and in a gaseous atmosphere containing oxygen by 40% and nitrogen by 60% and having a relative humidity of 70% at 25° C. for crystallizing the thin film (sintering step), followed by a cooling to the room temperature in the same humidity atmosphere (cooling step) to obtain a piezoelectric element of the present invention (FIG. 5). An analysis of an intermediate portion of the piezoelectric film provided a metal composition Pb 0.99 La 0.01 Zr 0.52 Ti 0.48 . The film thickness after coating and sintering three times was as follows.
TABLE 3 Preparation Examples of Film thickness Example coating liquid (μm) 10 2 0.79 11 5 1.43
Example 12
[0066] In this example, a piezoelectric element of the present invention was obtained in the same manner as in Example 6, except that air of a relative humidity of 60% at 25° C. was employed at a drying for 5 minutes at 150° C., and that air of a relative humidity of 80% at 25° C. was employed in a heat treatment which was executed by elevating the temperature from 400 to 600° C. at a rate of 2° C./min and maintaining for 10 minutes at 650° C. An analysis of an intermediate portion of the piezoelectric film provided a metal composition Pb 0.99 La 0.01 Zr 0.52 Ti 0.48 . The film thickness after coating and sintering ten times was 2.71 μm.
Example 13
[0067] Example 1 was reproduced except that the substrate was changed from a zirconia substrate to a Si wafer (FIG. 5). The film thickness after coating and sintering three times was 1.22 μm.
Comparative Examples 1-2
[0068] Piezoelectric elements were obtained in the same manner as in Examples 5 and 6, employing the coating liquid obtained in the Comparative Preparation Examples 1 and 2.
Evaluation
[0069] The piezoelectric element in each of Examples 1-13 and Comparative Examples 1-2 was prepared in 30 units, which were evaluated as follows.
[0070] An amount of displacement, under an application of a voltage of 10 V, 10 kHz between the upper electrode and the lower electrode was measured by a laser Doppler method. Table 4 shows an average and a standard deviation of an initial displacement in 30 elements and a displacement after an operation for 720 hours.
[0071] As will be observed from Table 4, the elements showed a larger displacement in comparison with those of Comparative Examples, and a satisfactory operation after a durability test for 720 hours. Also there were obtained elements of a smaller unevenness in the piezoelectric characteristics, in comparison with those of Comparative Examples.
TABLE 4 Displacement after Initial displacement operation for 720 hours Average Aver- displacement Standard age displacement Standard (μm) deviation (μm) deviation Ex. 1 1.21 0.52 1.10 0.58 Ex. 2 0.81 0.47 0.76 0.49 Ex. 3 0.88 0.44 0.80 0.50 Ex. 4 0.62 0.48 0.55 0.54 Ex. 5 0.78 0.61 0.62 0.67 Ex. 6 0.82 0.51 0.79 0.54 Ex. 7 1.08 0.53 1.05 0.54 Ex. 8 1.42 0.55 1.39 0.58 Ex. 9 0.87 0.54 0.83 0.57 Ex. 10 1.23 0.51 1.18 0.52 Ex. 11 1.11 0.55 1.07 0.54 Ex. 12 1.05 0.50 1.02 0.52 Ex. 13 0.99 0.52 0.97 0.55 Comp. Ex. 1 0.52 0.62 0.31 0.63 Comp. Ex. 2 0.73 0.79 0.44 0.85 Comp. Ex. 3 Evaluation impossible due to cracks in coating
Other Evaluations
[0072] Polarization characteristics to an applied 5 electric field were measured in the piezoelectric elements prepared in Example 1 and Comparative Example 1. The measurement was conducted, with HVS-6000, manufactured by Radiants Inc., by applying a voltage of 20 V to the element to obtain a hysteresis curve, which is shown in FIG. 8.
[0073] [0073]FIG. 8 indicates that Example 1 showed a larger retentive polarization than in Comparative Example 1.
[0074] Since such apparent hysteresis can be utilized as a memory element, a memory can be constructed by arranging a plurality of such elements in such a manner that a voltage can be applied individually. More specifically, it can be utilized as a rewritable memory by writing information by supplying a drive signal according to the information to be recorded and by reading information by detecting the direction of polarization. In the use as such memory, the piezoelectric film preferably has a thickness of 0.1 to 2 μm.
[0075] As explained in the foregoing, the piezoelectric film prepared according to the present invention is usable not only as a piezoelectric element of an ink jet recording head but also in various devices such as a memory, a capacitor, a sensor or an optical modulator. FIGS. 6 and 7 illustrate an ink jet recording head provided with a nozzle plate 10 having a nozzle 6 a , and a path 11 for introducing ink. A satisfactory recording was made with such ink jet recording head. | A composition for forming a piezoelectric film containing a dispersoid obtained from a metallic compound includes at least one of 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]non-5-ene, and 1,4-diazabicyclo[2.2.2]octane. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus intended for purifying paper pulp by screening it in the liquid state.
There are at present a very large number of apparatus assuming this function. They generally comprise:
a closed tank,
a cylindrical screen inside this tank, the screen being pierced either by round holes or by elongated fine slits,
a rotor having profiled blades which move in the vicinity of and along the surface of the screen at a suitable linear speed,
nozzles for the admission of the crude pulp (unpurified), the evacuation of the purified pulp and the rejects stopped by the screen.
It may function either by centrifugal or by centripetal forces, depending on whether the pulp passes from the interior toward the exterior of the screen or in the reverse path.
Apparatus of this type are described in French Patent Nos. 1,271,054 and 1,546,515.
As the moving blades move in the liquid, they create around them zones of super pressure and reduced pressure which unclog the screen continuously owing to a to and fro movement of the liquid in its vicinity.
Without the continuous action of the rotor blades, the screen blocks immediately due to the accumulation of fibres and dirt on its surface. The unclogging blades are generally situated on the upstream face (in the direction of flow of the liquid) of the screen, that is to say, inside it for centrifugal operation and outside it for centripetal operation.
Centripetal apparatus in which the blades are situated on the downstream face of the screen, that is to say inside it, are however known. This last arrangement is particularly suitable when the openings in the screen are slits, and in this case it is already known that operation is improved by using slits having an asymmetrical clearing.
The dimensions of the perforations most generally used are from 1.5 to 2.5 mm in diameter for holes and from 0.25 to 0.7 mm in width for slits.
The concentration of the paper pulp (ratio of the weight of the dry fibres to the weight of water in the mixture) at which the known apparatus of this type utilising perforations of these sizes, function is generally low, of the order of 1%, and rarely exceeds 1.5 to 2%. The weakness of these concentrations is often inconvenient. In fact, in a scheme for the treatment of paper pulp, especially pulps obtained from old paper, it is of considerable interest to purify the pulp before refining it, that is to say to stop the contaminants before dividing them by refining. Now the minimum concentration for refining in a suitable manner is from 3 to 4%, and in density this demands the pulp after it has passed through purifiers, this operation often being expensive and cumbersome.
SUMMARY OF THE INVENTION
It is, therefore, of great interest to produce purifiers which are capable of operating at concentrations of from 3 to 4%, while at the same time making use of conventional perforations so as to obtain a high degree of purification even at relatively high concentrations and thus to allow immediate refining without a thickening operation. An apparatus of this type constitutes one of the objects of the present invention.
Moreover, it is known that it is worth sometimes operating with downstream blades (purification of granular particles using fine slits) and sometimes using upstream blades (purification of flat or elongated thin particles). It is another object of the invention to produce an apparatus which is capable both of centripetal and centrifugal operation.
An apparatus according to the invention comprises a closed tank containing at least one screen separating two chambers, said screen having a surface of revolution whose axis is the rotational axis of an internal rotor having a surface of revolution which is substantially parallel to that of the screen and having blades in the form of ridges of angular cross-section, one edge of which is directed approximately toward the axis while the other is inclined.
The rotor of the apparatus is capable of rotation in opposite directions, and means are provided for placing each chamber of the tank in communication, at will, with an inlet for crude pulp and an outlet for purified pulp.
The invention also relates to the following arrangements considered individually or in combination.
The means for placing the chambers in communication with the crude pulp inlet and the purified pulp outlet, comprise nozzles merging into the tank tangentially in the same rotational direction about the axis and this direction corresponds to the rotational direction of the rotor in which the face of the blades directed substantially radially towards the axis precedes the inclined face.
These nozzles communicate with the inlet for the crude pulp and the outlet for the purified pulp by means of valves, for example three-way valves.
These valves are coordinated with the rotational direction of the rotor so as to allow centripetal operation or centrifugal operation as desired.
In the case of centripetal operation, the rotational direction of the rotor is such that the inclined faces of the blades precede the faces directed toward the axis and vice versa in centrifugal operation.
The tank contains two reject pipes each communicating with one of the two chambers separated by the screen, these pipes being controlled by a valve or an equivalent arrangement.
The angle between the straight sections of the blades is of the order of 50° to 90°, the inclined face of each blade forming an angle of 20° to 30° with the tangent to the rotor on the straight side of the blade.
The rotor is cylindrical in shape, both ends being closed. The blades are arranged along the generatrices of the rotor.
The diameter of the rotor is in the range of from 70% to 85% of the diameter of the screen.
The ends of the blades comprise cheeks which are substantially perpendicular to the rotor axis.
The linear speed of the blades is of the order of 15 to 20 meters per second.
BRIEF DESCRIPTION OF THE DRAWINGS
These arrangements and all other features of the invention will be described in more detail with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic view, in a vertical, and axial section, of an embodiment of the apparatus of the invention;
FIG. 2 is a diagrammatic illustration, in perspective, of the apparatus shown in FIG. 1 when operating centripetally;
FIG. 3 is a diagrammatic illustration, in perspective, of the same apparatus as that shown in FIG. 1 when operating centrifugally;
FIG. 4 illustrates the progress of the pulp as it passes through the screen.
FIGS. 5 and 6 illustrate partial views, respectively in section and in plan view, of the shape of the rotor blades;
FIG. 7 illustrates the probable path of certain current of liquid;
FIG. 8 illustrates a shape of screen slit for centripetal operation; and
FIGS. 9 and 10 illustrate a mode of assembling the screen.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, it is seen that the apparatus comprises a tank 1 which is preferably closed by a detachable or opening lid 2. A screen 3 is located inside the tank 1 and has a surface of revolution which is preferably cylindrical and whose axis is denoted by numeral 16. The screen 3 is mounted inside the tank 1 in such a way that it defines and separates an external chamber 4 and an internal chamber 5. In the example shown, this is performed by mounting the screen 3 on terminal sleeves 17 and 18 in a sealed manner to the surface of the tank 1. The tank 1 is provided with two main nozzles 6 and 7 which are both connected to a source of crude pulp 19 and to a outlet for purified pulp 20 by means of three-way valves 12 and 13 or an equivalent arrangement. The valves 12 and 13 allow the chamber 4 and the chamber 5 to be placed selectively, at will, in communication with the inlet 19 and the outlet 20. They are coordinated by any suitable means in such a way that the chamber 4 communicates with the inlet 19 while the chamber 5 communicates with the outlet 20 and that while the chamber 5 communicates with the inlet 19, the chamber 4 communicates with the outlet 20.
It goes without saying that the valves 12 and 13 can be connected directly to the tanks or containers of crude pulp and of purified pulp by separate pipes.
The tank 1 also comprises two secondary or waste nozzles 8 and 9, one of which ends in the chamber 4 while the other ends in the chamber 5, which are intended to extract the rejects. The nozzle 8 is controlled by the valve 14 and the nozzle 9 by the valve 15.
A rotor 10 having axis 16 is located inside the screen 3, coaxially with the screen 3, rotated by any suitable means and bearing blades 11.
The rotor 10 has an external surface of revolution which is parallel to the surface of the screen 3 and which is preferably cylindrical so that the distance between the rotor and screen is substantially constant over its entire surface. The length of the rotor 10 along the axis 16 is approximately the same as that of the screen 3 and preferably slightly greater so that the ends of the rotor 10 extend beyond and cover those of the screen 3.
The blades 11 (see FIGS. 5 and 6) have two faces 11a and 11b at different inclinations. The face 11a is inclined at an angle α of the order of approximately 20° to 30°, to the wall of the rotor 10, while the face 11b is at an angle β, substantially perpendicular to this wall. The arrangement of the two faces 11a and 11b imparts to the blades the shape of ridges or projections on the surface of the rotor 10 having in the section perpendicular to the axis 16, the general shape of an angle, one side of which is directed approximately radially toward the axis 16 while the other side is inclined thereto, the value of the angle being preferably in the range of from approximately 50° to 90°.
The above-mentioned values are not strict. In particular, it is obvious that the angle between the face 11a and the tangent to the rotor 10 varies from one end of the blade to the other and is smaller at the foot of the blade than at its tip. In the context of the invention, it is sufficient for the values indicated to be substantially respected at one point of the blade 11 situated between its foot and its tip, or at a point in the area occupied by the blade on the rotor.
The apparatus formed in this way is capable of both centripetal operation with the unclogging blades downstream of the screen (FIG. 2) and of centrifugal operation with the blades upstream of the screen (FIG. 3). FIGS. 2 and 3 are diagrammatic illustrations in which the wall 17 separating chambers 4 and 5 has not been shown.
During centripetal operation (FIG. 2) the crude pulp enters through the nozzle 6, flows round the screen 3 because of the tangential position of the nozzle 6, passes through the screen 3 and issues in purified form through the nozzle 7 situated tangentially in such a way that the flow is facilitated by the rotation of the pulp induced by the rotor. The waste which has been stopped by the screen 3 is discharged through the nozzle 8. This is the circuit indicated by the Roman Numerals II and the arrows in solid lines in FIG. 1.
The rotor turns in the direction of the arrow 21, that is to say, in such a way that the inclined faces 11a are in front of the faces 11b in relation to the direction of rotation.
As shown in FIG. 2, the nozzles 6 and 7 are both mounted so as to enter into the tank tangentially in the same rotational direction as the liquid which, in the example illustrated, is the rotational direction of the rotor 10 during centrifugal operation, that is to say the direction in which the face 11b of the blades 11 precedes the face 11a.
In the example illustrated, the nozzles 6 and 7 are parallel but another relative arrangement can be adopted.
During centrifugal operation (FIG. 3), the crude pulp arrives through the nozzle 7 and in rotating in the direction of rotation of the rotor, passes through the screen 3 and leaves through the nozzle 6. The rejects are discharged through the nozzle 9. This is the circuit indicated by the Roman Numerals I and the arrows in broken lines in FIG. 1. FIG. 1 also shows the rotational directions of the rotor 10 by means of the arrows marked with Roman Numerals I and II.
In both cases, it should be noted that the position of the nozzles and the rotational directions of the rotor are selected so that the speed communicated to the pulp by the rotor is always in the direction of flow of the pulp in the nozzles 6 and 7. This is seen in FIGS. 2 and 3 with regard to the nozzle 7 and the rotation of the pulp inside the screen 3.
However, this is also the case with respect to the nozzle 6 and the rotational direction of the pulp in the chamber 4 inside the screen 3. In fact, when the pulp rotates, under the influence of the rotor, in a certain direction inside the screen, it naturally turns in the opposite direction outside the same screen as a result of the rebound of the liquid thrown by the rotor on to the walls of the perforations in the screen. This is illustrated in FIG. 4 for centripetal operation. The apparatus thus allows the centripetal or centrifugal method to be used. In addition, it allows operation at concentrations which can be as high as 3 to 4%.
In fact, for centrigual operation, (arrow 22, FIGS. 3 and 5), the face 11b which is perpendicular to the movement creates a strong super-pressure which allows the thick pulp to pass through the screen, and acts as a form of scraper which provides good unclogging of the screen.
For centripetal operation (arrow 21, FIGS. 2 and 5), the inclined face acts as a vane of a centrifugal pump and sends a large volume of liquid through the perforations, thereby unclogging them. In addition, the face which is perpendicular to the movement causes a marked reduction in pressure downstream of the blade and this permits the pulp to pass in a high concentration.
The rotor 10 preferably has the shape of a cylinder which is closed at both ends and on which the blades 11 are disposed along the generatrices, the blades running from one end to the other of the cylinder. This arrangement defines a fairly large volume for liquid between the body of the rotor 10 and the screen 3 and, in the case of centripetal operation, this volume which is beaten by the blades 11 is, in a manner of speaking, forced to pass through the screen 3 from the interior to the exterior and then to pass from the exterior to the interior of the screen under the influence of the reduced pressure prevailing behind the blade. This to and fro movement of a large volume of liquid ensures that the screen is cleaned well and, moreover, acts as a vehicle for the fibres in the pulp so that the pulp does not pass through the screen at the high average concentration of 3 to 4% but at a lower concentration. This considerable internal recirculation of liquid explains the fact that very fine perforations can be used (width of 0.25 mm for slits and 1.5 mm for holes), even with a concentration of 4%.
The diameter of the rotor is preferably of the order of from 70% to 85% of the diameter of the screen so as to define a suitable volume of liquid between the rotor and screen.
The distance between the end of the blades and the screen will preferably be of the order of a maximum of 1 mm.
The apparatus according to the invention actually functions with screens having perforations which have the same characteristics as the known purifiers, that is to say, holes of from approximately 1.5 to 2.5 mm in diameter and slits of from 0.25 to 0.75 mm in width.
In order to increase the effects of super-pressure and reduced pressure described above, the invention also proposes that the ends of the blades 11 in the vicinity of the ends of the rotor 10 be provided with cheeks 23 (see FIG. 5). These cheeks have the shape of narrow ears situated in a plane which is approximately perpendicular to the axis 16. Similarly, to further increase these effects while remaining in a reasonable range of absorbed power, the invention proposes that speeds of travel for the blades be adopted above 15 m/second and preferably between 15 and 20 m/second. The speeds generally adopted are of the order of 10 m/second.
Moreover, in the case of centripetal operation with slits, openings having an asymmetrical clearance 24, FIG. 8, inclined in the direction opposite to the rotational direction 21 and which facilitates the passage of the liquid beaten by the blades will preferably be adopted in combination with the above.
The blades 11 can be two in number, extending over the entire length of the rotor 10 and diametrally opposed, as illustrated. However, the invention is not limited by this arrangement. Since the blades can be fairly numerous, it is also possible for them not to extend over the entire length of the rotor 10 but to be divided into blade sections preferably arranged so as to occupy the entire length of the rotor 10.
The apparatus illustrated has a horizontal axis. This arrangement is preferred but not essential and the axis may be inclined or even vertical.
The commutation of the valves 12, 13, 14, 15 and of the rotational direction of the rotor will preferably be coordinated by any suitable means, so as to avoid mistakes.
In the above description, the rejects are discharged in a continuous manner during purification and forms a thicker pulp which is treated in a secondary apparatus with a particular view to recycling.
The scope of the invention will not be departed from by extracting the rejects discontinuously between two phases of purification.
In order to install or remove the screens 3, the invention proposes that the lower part of the tank 1 be provided with rails 25 on which terminal sleeves 17, 18 can roll or slide, for example by means of guide studs 26. This arrangement is illustrated in FIGS. 9 and 10 and is particularly advantageous for large machines in which the screens 3 with their sleeves 17 and 18 are particularly heavy. The arrangement illustrated allows the screen 3 to be extracted by sliding over a sufficient length to allow it to be taken up by an overhead crane.
Various alternative modes of production can be adopted without departing from the scope of the invention. In particular, the nozzles 6, 7 can be provided with branches controlled by separate valves instead of a single valve 12, 13 on each nozzle 6, 7 etc. | An apparatus for purifying paper pulp in the liquid state by screening. The apparatus comprising a cylindrical fixed screen disposed coaxially with a rotor within a housing. The rotor has longitudinal blades which, in section transverse to the rotor axis, have the general shape of an angle one side of the angle being substantially radial to the rotor and a second side inclined thereto. This apparatus is capable of both centripetal and centrifugal operation, and at concentrations of from 3 to 4%. | 1 |
RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 430,098, filed Jan. 2, 1974, which is abandoned with the filing of this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an anchor davit for small fishing boats such as are suitable for bass fishing.
2. The Prior Art
With the operation of small boats, handling the anchor and anchor line has entailed some problems. Typically, as for example in bass fishing, a boat anchor when raised is stowed in a position which enables it to drop quickly into the water when released by the anchor reel for "immediate anchor control". This "quick drop" position usually locates the anchor in a generally vertical position, suspended at the side of a boat from an anchor davit which guides the anchor line to the reel. These davits allow the anchors to swing, especially in choppy waters, with damage frequently inflicted on the boat hull by the heavy swinging anchor.
More recently mushroom-type anchors have come into wide use. These anchors include a massive head portion with a shank or stem protection to which the anchor line is attached. They are constructed mostly of solid lead with a soft plastic vinyl coating as a protection for the boat hulls. Davits used with this type of anchor often provide means to resist anchor swing, provided the anchor is properly "stowed". Herein, the anchor is reeled up tightly against a rigid metal protrusion of the davit structure to minimize anchor swing while still providing immediate anchor control. Because the anchor is stowed at the boat's side and is somewhat obscured from view, it becomes rather difficult to see when the anchor is properly stowed. Further, fixed unyielding davit edges which the anchor is stowed against can cut and damage the anchor's plastic coating.
A further development in past davit designs provided a davit which stowed the anchor in a more visible, generally horizontal position above the boat's side. Herein, the anchor shank is pulled up over the anchor line guide roller and into a fixed, metal, retaining loop and against a pair of protruding ears for stowing. This design, however, holds only one size anchor shank tightly enough to prevent bouncing when negotiating rough waters. Further, anchors frequently become trapped or caught in these davits, necessitating the unsafe practice of standing and moving about the boat to free the anchor by pushing it out of the davit by hand.
SUMMARY OF THE INVENTION
With the anchor davit of the present invention, an anchor line is guided and supported on a roller rotatably mounted on the davit frame while handling an anchor in the water. A retaining loop, mounted for pivotal movement about the roller, retains the anchor line on the roller. The loop is supported in a generally horizontal position to effectively retain the anchor line on the roller. When raising the anchor out of the water for stowing, the retaining loop, upon making contact with the rising anchor, is pivoted from the anchor line retaining position to an anchor stowing position in which the anchor is brought into a clearly visible, generally horizontal position, secured against the retaining loop at the top and the roller at the bottom. The roller, which is preferably made of rubber or soft plastic, cushions the anchor to prevent damage to the anchor's plastic coating and also permits the use of anchors with different shank diameters and lengths.
A pair of tabs formed on the retaining loop or alternately a heavy wire bail mounted on the retaining loop are arranged to extend over the roller's edges to prevent the anchor line from wedging between the roller ends and the davit frame.
Accordingly, it is a principal object of this invention to provide an anchor davit which facilitates handling an anchor line and stows an anchor in a visible, safe, secure position which does not damage the anchor's plastic coating.
Another object of this invention is to provide an anchor davit which will stow the anchor in a visible, secure position and which accommodates positive, immediate control to drop the anchor when desired.
Still another object of this invention is to provide an anchor davit with a roller to center and support the anchor line, having a retaining loop arranged to prevent wedging of the line between the roller sides and the davit frame.
These and other objects and advantages will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view showing an anchor davit constructed in accordance with the principles of this invention, mounted to a boat hull for handling an anchor line and anchor;
FIG. 2 is a plan view of the davit of FIG. 1 showing the retaining loop in position to retain the anchor line;
FIG. 3 is a fragmentary sectional view taken along the line III--III in FIG. 2;
FIG. 4 is a side elevational view of the davit showing the anchor in a stowed position therein;
FIG. 5 is an end view of the davit with the retaining loop shown in the anchor stowing position;
FIG. 6 is a view similar to FIG. 5 showing a further embodiment of a means to prevent wedging of the anchor line;
FIG. 7 is a sectional view taken along the line VI-VI in FIG. 6; and
FIG. 8 is a side elevational view of the davit shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 of the drawings we show an anchor davit 10 mounted on a boat 12, to guide an anchor cable or line 14 over the boat's side 16. The anchor line 14 is wound on a reel 18 to hoist an anchor 20 out of the water whenever the boat 12 is to be moved. The anchor 20 is of the mushroom type, having a shank or stem portion 22 secured to the anchor line 14 as at 23, with a massive head portion 24 formed on the shank portion 22 remote from the anchor line connection 23. Preferably the anchor 20 is made of lead with a soft vinyl plastic covering 26 to protect the boat hull.
The anchor davit 10 includes a frame or bracket 28 with a rear mounting end 30 secured to the boat 12 by suitable fastenings such as screws 32, and having a front support end 34 extending outward beyond the boat side 16. The support end 34 includes a pair of spaced side members 36, 36 having an elastomeric roller 38 supported therebetween on a shaft 40. The roller 38 is spool-shaped and includes a pair of rim portions 42, 42 with a concave tapered recess 44 formed therebetween for guiding and supporting the anchor line 14 thereon. A face 46 at each side of the roller 38 is spaced a minimum distance away from the side members 36, 36 to preclude anchor line 14 from entering the spaces between the roller side faces 46 and the side members 36.
A retaining loop or strap 48 is pivotally carried by said shaft 40, extending about the roller 38 and around the outside of side members 36, 36. The retaining loop 48 comprises a "U" shaped strap with a pair of straight side mounting legs 52, 52 retained on stub portions 50, 50 at each end of the shaft 40 by snap rings 53, 53. The legs 52, 52 are connected by a curved bight 56 which is positionable relative to the roller 38 and the anchor line 14 to prevent disengagement therebetween, as best seen in FIG. 2.
A curved tab 58 formed in the leading edge 59 of each leg 52, following a continuing curvature of the bright 56, extends inward over the rim portions 42, 42 of the roller 38 to cover the spaces between the side members 36 and the roller faces 46, 46 to further prevent wedging or fouling of the anchor line 14 and to keep the line centered on the roller 38 and riding in the tapered recess 44.
With specific reference to FIG. 3, it will be seen that the retaining loop 48 comes to rest and is supported in the anchor line retaining position by a stop 54 formed in the side member 36. A trailing edge 57 of the leg 52 supports the retaining loop 48 at a somewhat elevated angle with respect to a horizontal plane H to facilitate the entry of the anchor 20 for stowing.
When the anchor 20 is raised out of the water by winding the anchor line 14 on the reel 18, as best seen in FIGS. 1 and 4, the stem portion 22 comes into contact with the roller recess 44 and is pulled up into the bright 56 of the retaining loop 48. As the reel 18 continues to wind in the anchor line 14, the anchor 20 is pivoted about the roller wherein the head portion 24 comes into contact with the leading edge 59 of the retaining loop 48 and the rim portions 42, 42 of the roller 38, causing the retaining loop 48 to pivot to an anchor stowing position as shown in FIG. 4.
The retaining loop 48 is held in this position by a second stop 60, formed in one of the side members 36 of the bracket 28, which limits further pivotal movement responsive to anchor line tension. Thus the anchor 20 is brought into a secure stowed position with its shank portion 22 extending into the bight 56 of the loop 48 and resting in the centering recess 44 of the roller 38 with the anchor's enlarged head portion 24 brought to bear firmly against the leading edge 59 of the retaining loop 48 and the rim portions 42, 42 of the elastomeric roller 38. Herein, the anchor 20 is cushioned by the elastomeric roller 38 to protect its vinyl coating 26 from damage and keep the anchor from bouncing when the boat 12 encounters rough waters. Further, davits of the present invention permit anchors with various shank sizes to be suitably stowed and protected.
While stops 60 and 54 are shown in the preferred embodiment as formed integral with the bracket 28, they may be of any sutiable construction and location to station the retaining loop 48 in related anchor stowing or anchor line retaining portions.
When the anchor line tension is released by the reel 18, the retaining loop 48 allows the anchor 20 to lower by pivoting downward, around the roller 38 and with the anchor 20, to a position where the anchor shank 22 drops free of the encircling retaining loop 48 and into the water. The stop 60 fixes the stowing position of the retaining loop 48 at a slightly downward disposed angle, with respect to a vertical plane V whereby gravity causes the loop 48 to drop to the anchor line retaining position, following the anchor's descent. Herein, the anchor 20 will never be trapped or fouled by the davit 10, thereby providing the "immediate anchor control" required for safe and dependable boat operation.
The curved tabs 58, formed in the mounting legs 52, effectively cooperate with the rim portions 42, 42 to keep the anchor line 14 centered in the tapered recess 44 of the roller 38 when larger diameter anchor lines are utilized. However, when a small diameter soft anchor line is used it is possible for the line when slack and when pulled out at a sharp angle by a sideways movement of the boat, to be forced in under one of the guide tabs 58 and to wedge under a roller end. Further, the rope may also wear against the tab edges for a few feet before slipping back into the recess 44. This wear, while slight, is still undesirable.
To eliminate these possibilities, a heavy wire, bail 66 is provided in place of the tabs 58, as a alternate form of the invention as shown in FIGS. 6 to 8, to maintain a small diameter anchor line 14a centered on the roller 38. The bail 66 defines a generally "U" shaped anchor line restraining guide 68. The restraining guide 68 includes a pair of spaced legs 70, 70 contoured to conform to the curvature of the roller 38 and disposed in a juxtaposed position along a substantial peripheral portion of the underside of each roller rim 42, immediately adjacent inner edges 43, 43 thereof. This peripheral portion of the roller rims includes the full range of anchor line dependency from the roller, consistent with anchor deployment under conditions of maximum boat drift as best seen in FIG. 7 of the drawings. The contoured legs 70, 70 of the restraining guide 68 are joined at one end by a transverse leg 72 which extends across the tapered recess 44, well behind a point of possible contact with the anchor line 14a, as best seen in FIG. 7.
Each contoured leg includes a short angled portion 74 which terminates in an out-turned stub extension 75 providing a means of mounting the bail 66 to the retaining loop 48 for pivotal movement therewith. Each stub extension 75 is carried in a complimentary aperture 76 formed near the leading edge 59 of each of the legs 52 of the retaining loop 48 and may be secured therein by welding or suitable fastening devices or may be adequately retained in the apertures 76, 76 by inherent spring tension in the bail 66. Herein, bights 78, 78 formed at the junctures of the angled portions 74, 74 and the stub extensions 75, 75, are pressed into contact with the retaining loop legs 52 to obtain a hold thereon to accommodate pivotal movement of the contoured legs 70, 70 about the roller 38, coincidential with the retaining loop 48. Thus the bail 66 is pivoted from a non-obstructive position relative to the anchor 20 as seen in FIG. 8 to an operative position to prevent anchor line fouling, with the movement of the retaining loop 48 from its second, anchor stowing position to its first anchor line retaining position.
With specific reference to FIG. 6 of the drawings in which the anchor 20 has been dropped and the boat subjected to considerable side drift, the anchor line 14a is restrained and guided over the rounded edges of the contoured legs 70, 70 to prevent excessive transverse deflection which may otherwise allow the anchor line to become wedged between side members 36 and the roller faces 46 when the anchor is raised.
When hoisting the anchor 20 and stowing it as shown in FIG. 8, the contoured legs 70, 70 of the restraining guide 68 are interposed between the anchor head portion 24 and the roller rim portions 42 and serve as the lower stop or abutment when the hoisting or lifting force is applied to the anchor line 14a by the reel 18 to secure the anchor 20 in its stowed position. The pivotal movement of the retaining loop 48 to its second position accommodates the placement of the anchor 20 in a gravitationally responsive inclination from which position the anchor freely drops clear of the anchor davit 10, back into the water upon releasing the hoisting force tension on the anchor line.
Thus the anchor is remotely controlled by the reeling force to wind in the anchor line 14 and stow the anchor in a secure position and to instantaneously drop the anchor from the stowed position by simply releasing the tension or lifting force on the anchor line. Accordingly, a positive responsive control is provided to raise, stow and drop the anchor from a safe convenient location in the boat without the need to move about the boat to manually lower the anchor.
It will be seen from the foregoing that we have provided a greatly improved anchor davit which will stow an anchor in a safe, secure, visible position and which cushions the anchor to protect against damage and prevents unpleasant anchor bouncing in rough water. Further, the anchor line is retained on the davit roller, free from wedging or fouling under the roller.
It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as may reasonably occur to a person skilled in the art. | An anchor davit to facilitate handling an anchor cable and to stow the anchor in a safe, secure position when it is raised out of the water. The davit provides a cable centering, direction changing roller, rotatably supported on a mounting bracket to guide the cable over the side of a boat and to cradle and cushion the raised anchor. A retaining loop, pivotally supported on the bracket, is coaxial with the roller and cooperates therewith to hold the cable on the roller and brings about a suitable stowing position of the anchor. | 1 |
This application claims benefit of Japanese Patent Applications No. 2008-125399 filed in Japan on May 13, 2008 and No. 2008-125400 filed in Japan on May 13, 2008, the contents of which are incorporated by these references.
BACKGROUND OF THE INVENTION
The present invention relates to a solid-state imaging apparatus for use in a camcorder, a digital still camera, and others and, more specifically, to a solid-state imaging apparatus using an amplified solid-state imaging device that has an amplifier capability in an imaging area.
Imaging apparatuses such as digital cameras have recently started using MOS (Metal Oxide Semiconductor) image sensors. The MOS image sensors each have an active element in a pixel as an imaging device, thereby allowing on-chip peripheral circuits. FIG. 1 shows the circuit configuration of a MOS image sensor of a general type. The general MOS image sensor usually carries a plurality of pixels arranged two dimensionally, but for simplification, FIG. 1 shows only three pixels P 11 , P 12 , and P 13 arranged in a row. These pixels P 11 , P 12 , and P 13 are configured to each include a photodiode PD, a transfer transistor M 1 , a reset transistor M 2 , and a selection transistor M 4 , and respectively include floating diffusion sections FD 11 , FD 12 , and FD 13 , and amplification transistors M 311 , M 312 , and M 313 . The floating diffusion sections FD 11 , FD 12 , and FD 13 are those each having a capacitance. The pixels P 11 , P 12 , and P 13 are coupled to each corresponding correlated double sampling circuit (CDS circuit) 10 respectively via vertical signal lines 31 , 32 , and 33 . The vertical signal lines 31 , 32 , and 33 are respectively coupled to bias transistors M 51 , M 52 , and M 53 at their each one end. The bias transistors M 51 , M 52 , and M 53 each serve as a constant-current source with their other ends being-grounded. These bias transistors M 51 , M 52 , and M 53 are under the control of a bias current adjusting voltage Vbias.
The CDS circuits 10 are each configured to include a clamp transistor M 11 , a sample hold transistor M 12 , a clamp capacitor C 11 , and a sample hold capacitor C 12 . The CDS circuits 10 are coupled to a horizontal signal line 7 via their corresponding column selection transistors M 6 , and are so configured as to output image signals via an output amplifier 5 . Various types of pulses are provided respectively from a vertical scanning section 2 and a horizontal scanning section 4 under the control of a timing control section 6 . The various types of pulses include a transfer pulse φTR 1 , a reset pulse φRST 1 , and a row selection pulse φROW 1 , which are respectively related to the control of the transistors in each of the pixels, i.e., the transfer transistor M 1 , the reset transistor M 2 , and the selection transistor M 4 . The various types of pulses also include column selection pulses φH 1 , φH 2 , and φH 3 , which are related to the control of the column selection transistors M 6 . Other pulses related to the control of the clamp transistor M 11 and the sample hold transistor M 12 , i.e., a clamp pulse φCL, and a sample hold pulse φSH, are to be output from the timing control section 6 .
The MOS image sensor configured as above suffers from image quality deterioration due to the varying threshold value of the amplification transistors M 311 to M 313 , and the reset noise of the reset transistor M 2 in every pixel. However, such noise can be removed by finding a pixel-output difference in each of the CDS circuits 10 , i.e., a difference between the pixel output after the resetting and the pixel output after the transferring of the signal charges of the photodiode PD. With the noise favorably removed as such, only optical signals serving as image signals can be output.
The MOS image sensor provided with the CDS circuits is known to generate, when a high-luminance light enters thereinto, a completely black image that looks like a result of no entry of light. Such a phenomenon is hereinafter referred to as black sun phenomenon. Described next is such a black sun phenomenon in the MOS image sensor. FIG. 2 is a timing chart for illustrating the operation of causing the black sun phenomenon when a high-luminance object is imaged. Exemplified here is a case where a high-luminance light is being directed to the center pixel P 12 of FIG. 1 , but a light is hardly entered to the remaining pixels P 11 and P 13 .
(1) First of all, in a reset period T 1 , when a row selection pulse φROW 1 is in the state of H (High) level, a reset pulse φRST 1 is set to the H level, and the floating diffusion sections FD 11 , FD 12 , and FD 13 of each pixel are fixed to a power supply voltage VDD. In the CDS circuits 10 , a clamp pulse φCL and a sample hold pulse φSH are both set to the H level.
(2) In the next reset sampling period T 2 , the reset pulse φRST 1 is set to the L (Low) level. In this period, in the pixels P 11 and P 13 not being exposed to a high-luminance light, the floating diffusion sections FD 11 and FD 13 respectively show no change of their voltages VFD 11 and VFD 13 (VFD 13 is not shown), but in the pixel P 12 being exposed to a high-luminance light, the floating diffusion section FD 12 drops its voltage VFD 12 as shown in the drawing due to the leakage of charge from the photodiode PD, for example. This resultantly causes the reduction of a potential V 32 (Rst) of the vertical signal line 32 that is coupled with the pixel P 12 , thereby deriving (VFD 12 −VGS-M 312 ). Note here that this term of VGS-M 312 denotes the gate-source voltage of the amplifier transistor M 312 of the pixel P 12 . At the end of the reset sampling period T 2 , the potential of each of the vertical signal lines 31 to 33 are clamped with the clamp pulse φCL being set to the L level in the CDS circuits 10 .
(3) In the following signal transfer period T 3 , with a transfer pulse φTR 1 being set to the H level, the signal charges of the photodiode PD in each of the pixels P 11 to P 13 are transferred to their corresponding floating diffusion sections FD 11 to FD 13 . At this time, the voltage VFD 12 of the floating diffusion section FD 12 in the pixel P 12 being exposed to the high-luminance light is already reduced in the reset sampling period T 2 . Therefore, even if the charges of the photodiode PD are transferred, the resulting voltage change is not that much from the value in the reset sampling period T 2 , i.e., no voltage change is observed when the voltage VFD 12 of the floating diffusion section FD 12 has reached its bottom value due to the leakage of charge. As a result, the vertical signal 32 also shows a slight change of the potential V 32 (Sig). Note here that, at this time, because the pixels P 11 and P 13 are assumed as being hardly exposed to a light, the remaining vertical signal lines 31 and 33 also hardly show a change of potential.
(4) In the following signal sampling period T 4 , with the processing operation of the CDS circuits 10 , the potential difference [V 32 (Rst)−V 32 (Sig)] is retained at the sample hold capacitor C 12 . The potential difference being the processing result in each of the CDS circuits 10 are output as image signals via the column selection transistors M 6 and the output amplifier 5 . At this time, in the pixel P 12 being exposed to the high-luminance light, a black sun phenomenon is observed due to the variation of the potential V 32 (Rst) of the vertical signal line 32 in the reset sampling period T 2 , i.e., the potential difference [V 32 (Rst)−V 32 (Sig)] being the CDS processing result is small, and thus the output looking black is output as an image signal.
Such a problem of black sun phenomenon can be solved with still image shooting if a mechanical shutter is provided. However, with moving image shooting not using a mechanical shutter, for example, the black sun phenomenon is inevitable.
There is another concern that the entering of the high-luminance light may affect any pixel areas other than the pixel being exposed thereto. FIG. 3 is a timing chart for illustrating the operation of causing a highlight transverse stripe phenomenon to be observed around the pixel being exposed to a high-luminance light. Exemplified here is also a case where a high-luminance light is being directed to the center pixel P 12 of FIG. 1 , but a light is hardly entered to the remaining pixels P 11 and P 13 . This example is with an assumption that no black sun phenomenon is to be observed.
(1) First of all, in the reset period T 1 , similarly, when a row selection pulse φROW 1 is in the state of H level, a reset pulse φRST 1 is set to the H level, and the voltages of the floating diffusion sections FD 11 , FD 12 , and FD 13 of each of the pixels, i.e., voltages VFD 11 to VFD 13 , are all fixed to the power supply voltage VDD. In the CDS circuits 10 , a clamp pulse φCL and a sample hold pulse φSH are both set to the H level.
(2) In the next reset sampling period T 2 , at the end thereof, the clamp pulse φCL is set to the L level in the CDS circuits 10 , and the voltages of the floating diffusion sections FD 11 to FD 13 of each of the pixels are clamped to the CDS circuits 10 respectively via the vertical signal lines 31 to 33 .
(3) In the following signal transfer period T 3 , with a transfer pulse φTR 1 being set to the H level, the signal charges of the photodiode PD in each of the pixels P 11 to P 13 are transferred to their corresponding floating diffusion sections FD 11 to FD 13 . At this time, the voltage VFD 12 of the floating diffusion section FD 12 in the pixel P 12 being exposed to the high-luminance light is largely reduced from the power supply voltage VDD due to the large amount of signal charges therein. Therefore, the potential V 32 of the vertical signal line 32 coupled with the pixel P 12 is largely reduced down to (VFD 12 −VGS-M 312 ). This accordingly reduces the drain-source voltage of the bias transistor M 52 coupled to the vertical signal line 32 , thereby reducing the current flowing to the bias transistor M 52 . This reduction of the current thus reduces any possible voltage drop to be caused by the GND resistance of a GND line coupled to all of the sources of the bias transistors M 51 to M 53 so that the gate-source voltage is increased in the bias transistors M 51 and M 53 respectively coupled to the vertical signal lines 31 and 33 . As a result, the current flowing to the vertical signal lines 31 and 33 is increased. This increase of the current then increases the gate-source voltage in the amplification transistors M 311 and M 313 of the pixels P 11 and P 13 , respectively, so that the potentials V 31 and V 33 of the vertical signal lines 31 and 33 will be in the level lower by ΔV than the reset level output (VDD).
(4) In the following signal sampling period T 4 , with the processing operation of the CDS circuits 10 , the difference between the reset potential and the optical-signal-reading potential after the transferring of the signal charges in the vertical signal lines 31 to 33 is output as an image signal via the column selection transistors M 6 and the output amplifier 5 . At this time, in the pixels P 11 and P 13 in the vicinity of the pixel P 12 being exposed to the high-luminance light, the potential difference ΔV from the reset level is detected due to the variation of the current via the GND line coupled to the bias transistor M 52 as described above. Thus detected potential difference ΔV will look a white float-like image, thereby causing the highlight transverse stripe phenomenon in the image signal.
In the MOS image sensor as such, when a window chart is imaged, such images as shown in FIGS. 4A to 4D may be derived due to the black sun phenomenon and the highlight transverse stripe phenomenon. FIG. 4A shows the pattern of an object with a high-luminance light at the center, and FIG. 4B shows the state in which the black sun phenomenon is observed due to the variation of the reset potential. FIG. 4C shows the state in which the highlight transverse stripe phenomenon is observed due to the variation of the signal potential, and FIG. 4D shows the state in which the black sun phenomenon is observed together with the highlight transverse stripe phenomenon.
JP-A-2007-20156 describes the previous technique as below not to cause the black sun phenomenon and the highlight transverse stripe phenomenon in the MOS image sensor described above. That is, with the technique, as shown in FIG. 5 , clipping circuits 71 to 73 are provided respectively to the vertical signal lines 31 to 33 to selectively restrict the potentials thereof to be the value of a first or second potential. With such a configuration, the pixel output after the resetting of the pixels is so controlled as not to be the value of the first potential or lower, and the pixel output after the transferring of the signal charges is so controlled as not to be the value of the second potential or lower. Note here that the clipping circuits 71 to 73 are respectively configured to include clipping transistors M 71 to M 73 , and clipping selection transistors M 81 to M 83 . In the configuration, the gates of the clipping transistors M 71 to M 73 are coupled to a clipping voltage Vclip, and the drains thereof are coupled to the power supply voltage VDD. The gates of the clipping selection transistors M 81 to M 83 are applied with a clipping selection pulse φROWD, and the sources thereof are respectively coupled to the vertical signal lines 31 to 33 . The clipping voltage Vclip and the clipping selection pulse φROWD are to be output from the timing control circuit 6 .
Described next is the operation of the MOS image sensor provided with the clipping circuits as in the above configuration by referring to the timing chart of FIG. 6 . Exemplified also here is a case where a high-luminance light is being directed to the center pixel P 12 of FIG. 5 , but a light is hardly entered to the remaining pixels P 11 and P 13 therearound.
(1) First of all, in the reset period T 1 , a row selection pulse φROW 1 is set to the H level, and the clipping voltage Vclip is set to a first level VclipH, i.e., the level being lower than the power supply voltage VDD but not causing the black sun phenomenon. A reset pulse φRST 1 is set to the H level, and the floating diffusion sections FD 11 , FD 12 , and FD 13 of each of the pixels are fixed to the power supply voltage VDD. In the CDS circuits 10 , a clamp pulse φCL and a sample hold pulse φSH are both set to the H level.
(2) In the next reset sampling period T 2 , in the pixel P 12 being exposed to a high-luminance light, the floating diffusion section FD 12 shows a considerable reduction of its voltage VFD 12 due to the leakage of charge from the photodiode PD, for example. As a result, when there is no clipping circuit provided, the potential V 32 of the vertical signal line 32 is also reduced to a considerable degree. In this example, however, with the clipping circuit 72 provided, the potential V 32 (Rst) of the vertical signal line 32 will not be reduced to or below the potential of (VclipH−VGS-M 72 ) as is clipped thereto. This accordingly prevents any possible black sun phenomenon from occurring also by the differential processing to be executed next by the CDS circuits 10 . Note here that the term of VGS-M 72 denotes the gate-source voltage of the clipping transistor M 72 . At the end of the reset sampling period T 2 , the potentials of the vertical signal lines 31 to 33 are clamped with the clamp pulse φCL being in the L level in the CDS circuits 10 .
(3) In the following signal transfer period T 3 , the level of the clipping voltage Vclip is changed to a second level VclipL in which no highlight transverse stripe phenomenon is to be caused, and by setting the transfer pulse φTR 1 to the H level, the charges of the photodiode PD in each of the pixels P 11 to P 13 are transferred to the corresponding floating diffusion sections FD 11 to FD 13 . At this time, the voltage VFD 12 of the floating diffusion section FD 12 in the pixel P 12 being exposed to the high-luminance light is largely reduced. As such, when there is no clipping circuit provided, the potential V 32 of the vertical signal line 32 is also largely reduced, and the drain-source voltage of the bias transistor M 51 is reduced down to a value outside of the range of operating the bias transistor M 51 , thereby causing highlight transverse stripe. However, if the voltage of the clipping circuit, i.e., voltage VDD 2 , is set to the second clipping level VclipL, the voltage V 32 of the vertical signal line 32 will not down to or below the value of (VclipL−VGS-M 72 ) as is clipped thereto, thereby operating the bias transistor M 51 . This accordingly prevents any possible highlight transverse stripe from occurring.
(4) In the following signal sampling period T 4 , with the processing operation of the CDS circuits 10 , the potential difference of the vertical signal lines 31 to 33 , i.e., the difference between the reset potential and the optical-signal-reading potential after the transferring of the signal charges, is retained at the sample hold capacity C 12 . The potential difference is then output, via the column selection transistors M 6 and the output amplifier 5 , as an image signal free from the black sun phenomenon and the highlight transverse stripe phenomenon.
As described above, with the clipping circuits provided as such, any possible black sun phenomenon and highlight transverse stripe phenomenon can be both favorably prevented.
SUMMARY OF THE INVENTION
A first aspect of the invention is directed to a solid-state imaging apparatus including a pixel section and a control means, the pixel section having a two-dimensional matrix of a plurality of pixels each provided with: photoelectric conversion means for converting an incident light into a signal charge; a storage section that stores therein the signal charge; transfer means for transferring the signal charge to the storage section; amplification means for amplifying the signal charge stored in the storage section for output as a pixel signal; and reset means for resetting the storage section through supply of a potential retained at a reset line to the storage section. The pixel section also includes, on a column basis, an output signal line whose one end is coupled to one end of a constant-current source whose remaining end is grounded, and through which the pixel signal is output. In the pixel section, the area carrying thereon the two-dimensional matrix of the pixels includes a light-shielding area with light shielding properties, a read area for reading a pixel signal corresponding to the incident light, and a transition area disposed between the light-shielding area and the read area. The control means selects any of the pixels being coupled to the same output signal line and being in the read area as a first pixel, and selects any of the pixels being coupled to said the same output signal line and being in the transition area as a second pixel. The control means then resets the second pixel by the reset means when outputting the pixel signal corresponding to the incident light from the first pixel to the output signal line. Using the pixel signal to be output at this time to the output signal line from the second pixel, the control means performs control to keep the potential difference between the one end and the other end of the constant-current source in a range with which the constant-current source can be operated.
In a second aspect of the invention, in the solid-state imaging apparatus of the first aspect, the control means uses the pixel signal from a plurality of the second pixels to perform the control over the constant-current source to keep the potential difference thereof in the range.
In a third aspect of the invention, in the solid-state imaging apparatus of the second aspect, the control means performs control to change the combination of the plurality of the second pixels for use to keep the potential difference of the constant-current source in the range.
In a fourth aspect of the invention, in the solid-state imaging apparatus of the first aspect, the control means also uses a pixel signal from the first pixel that is not a read target from the read area for the pixel signal corresponding to the incident light to perform the control over the constant-current source to keep the potential difference thereof in the range.
In a fifth aspect of the invention, in the solid-state imaging apparatus of the first aspect, the control means controls the second pixel outputting the pixel signal to make the potential difference between the one end and the other end of the constant-current source to be a lower limit of the range with which the constant-current source can be operated.
A sixth aspect of the invention is directed to a solid-state imaging apparatus including a pixel section, a noise suppression circuit, and control means, the pixel section having a two-dimensional matrix of a plurality of pixels each provided with: photoelectric conversion means for converting an incident light into a signal charge; a storage section that stores therein the signal charge; amplification means for amplifying the signal charge stored in the storage section for output as a first output signal to a signal output line; and reset means for resetting the storage section through supply of a reset potential supplied to a reset line to the storage section. In the pixel section, the area carrying thereon the two-dimensional matrix of the pixels includes a light-shielding area with light shielding properties, a read area for deriving the first output signal corresponding to the incident light, and a transition area disposed between the light-shielding area and the read area. The noise suppression circuit calculates a difference between the first output signal and a second output signal being an output to the signal output line as a result of a reset operation by the reset means in the same pixel outputting the first output signal, and performs a noise suppression operation to suppress any noise found in the first output signal. The control means performs control to set a lower limit value for the second output signal on the signal output line using a third output signal being an output to the signal output line as a result of the reset operation by the reset means in the second pixel found in the transition area coupled to the signal output line same as that for the first pixel, at the time of outputting the second output signal related to the first pixel included in the read area.
In a seventh aspect of the invention, in the solid-state imaging apparatus of the sixth aspect, the control means plurally sets the second pixel for use as the second pixel.
In an eighth aspect of the invention, in the solid-state imaging apparatus of the seventh aspect, the control means plurally sets the second pixel satisfying any predetermined requirements.
In a ninth aspect of the invention, in the solid-state imaging apparatus of the sixth aspect, the control means sets the lower limit value for the second output signal on the signal output line also using a fourth output signal being an output to the signal output line as a result of the reset operation by the reset means in the first pixel that is included in the read area but is not a read target.
In a tenth aspect of the invention, in the solid-state imaging apparatus of the sixth aspect, the control means sets a potential of the third output signal to be lower than a potential of the second output signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit configuration diagram of a general MOS image sensor.
FIG. 2 is a timing chart for illustrating the state of the MOS image sensor of FIG. 1 in which a black sun phenomenon is observed.
FIG. 3 is a timing chart for illustrating the state of the MOS image sensor of FIG. 1 in which a highlight transverse stripe phenomenon is observed.
FIGS. 4A to 4D are each a schematic diagram showing an object pattern with a high-luminance light at the center, and the state in which the black sun phenomenon and/or the highlight transverse stripe phenomenon is observed in the MOS image sensor of FIG. 1 .
FIG. 5 is a circuit configuration diagram of a previous MOS image sensor provided with clipping circuits.
FIG. 6 is a timing chart for illustrating the operation of the MOS image sensor of FIG. 5 .
FIG. 7 is a diagram showing an effective area, a light-shielding area, and a transition area therebetween in a general pixel section in a solid-state imaging apparatus.
FIG. 8 is a circuit configuration diagram of a solid-state imaging apparatus in a first embodiment of the invention.
FIG. 9 is a timing chart for illustrating the operation of the solid-state imaging apparatus of the first embodiment of FIG. 8 .
FIG. 10 is a diagram showing a plurality of clipping-voltage-generation pixel rows in a pixel section of a solid-state imaging apparatus of a second embodiment.
FIG. 11 is a partially-simplified circuit configuration diagram of the solid-state imaging apparatus of the second embodiment.
FIG. 12 is a timing chart for illustrating the operation of the solid-state imaging apparatus of the second embodiment of FIG. 11 .
FIG. 13 is a diagram showing a clipping-voltage-generation pixel row in a pixel section of a solid-state imaging apparatus of a third embodiment.
FIG. 14 is a diagram showing clipping-voltage-generation pixel rows in a pixel section of a solid-state imaging apparatus of a fourth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Described next are some embodiments of the solid-state imaging apparatus of the invention by referring to the accompanying drawings.
Embodiment 1
The invention is aimed to enable the clipping operation for vertical signal lines with no need to separately provide a clipping circuit but using a pixel output from a pixel section to prevent a black sun phenomenon and a highlight transverse stripe phenomenon. In a first embodiment, the clipping operation uses the pixel output specifically from a transition area in the pixel section. That is, as shown in FIG. 7 , in a pixel section 100 , the center portion generally serves as an effective area 101 for forming an image signal, and the remaining peripheral portion serves as a light-shielding area 102 for outputting the black level. Between the effective area 101 and the light-shielding area 102 , formed is a transition area (margin area) 103 , which is not used for deriving an image signal in view of the quality thereof. In this embodiment, the clipping operation is performed using pixels included in this transition area 103 .
Described next is the specific configuration of the first embodiment. FIG. 8 is a circuit configuration diagram of the solid-state imaging apparatus of the first embodiment. In FIG. 8 , any component similar to or corresponding to that in the previous solid-state imaging apparatus of FIG. 1 is provided with the same reference numeral, and is not fully described again. Also in the solid-state imaging apparatus of this embodiment, a pixel section is configured by a plurality of pixels arranged two dimensionally, but for simplicity, FIG. 8 shows only pixels P 11 to P 13 and P 21 to P 23 , arranged three each in two rows. The pixels P 11 to P 13 in the first row are those in the effective area, and the pixels P 21 to P 23 in the second row are those in the transition area. These pixels P 11 to P 23 are configured to each include a photodiode PD, a transfer transistor M 1 , a reset transistor M 2 , and a selection transistor M 4 , and respectively include floating diffusion sections FD 11 to FD 13 and FD 21 to FD 23 , and amplification transistors M 311 to M 313 and M 321 to M 323 . The floating diffusion sections FD 11 to FD 23 are those each having a capacitance. Three pairs of the pixels P 11 to P 23 arranged in the column direction are respectively coupled to the vertical signal lines 31 , 32 , and 33 , and the vertical signal lines 31 to 33 are coupled to each corresponding CDS circuit 10 . The vertical signal lines 31 to 33 are respectively coupled to the bias transistors M 51 to M 53 at their each one end. The bias transistors M 51 to M 53 each serve as a constant-current source with their other ends being grounded. These bias transistors M 51 to M 53 are under the control of a bias current adjusting voltage Vbias.
The CDS circuits 10 are each configured to include a clamp transistor M 11 , a sample hold transistor M 12 , a clamp capacitor C 11 , and a sample hold capacitor C 12 . The CDS circuits 10 are coupled to the horizontal signal line 7 via their corresponding column selection transistors M 6 , and are so configured as to output image signals via the output amplifier 5 . Various types of pulses are provided respectively from the vertical scanning section 2 and the horizontal scanning section 4 under the control of the timing control section 6 . The various types of pulses include transfer pulses φTR 1 and φTR 2 , reset pulses φRST 1 and φRST 2 , and row selection pulses φROW 1 and φROW 2 , which are respectively related to the control of the transistors in each of the pixels, i.e., the transfer transistor M 1 , the reset transistor M 2 , and the selection transistor M 4 . The various types of pulses also include column selection pulses φH 1 to φH 3 , which are related to the control of the column selection transistor M 6 . A pixel power supply VDD 1 for the pixels P 11 to P 13 in the first row are fixed to the power supply voltage VDD. On the other hand, a pixel power supply VDD 2 for the pixels P 21 to P 23 in the second row is to be changed between first and second clipping voltages VclipH and VclipL by the timing control section 6 via the vertical scanning section 2 . The first clipping voltage VclipH is slightly lower than the power supply voltage VDD, and a black sun phenomenon does not occur therewith. The second clipping voltage VclipL is lower than the first clipping voltage VclipH, and a highlight transverse stripe phenomenon does not occur therewith. Other pulses related to the control of the clamp transistor M 11 and the sample hold transistor M 12 , i.e., a clamp pulse φCL, and a sample hold pulse φSH, are to be output from the timing control section 6 .
Described next is the operation of the solid-state imaging apparatus of the first embodiment configured as such by referring to the timing chart of FIG. 9 . Exemplified here is a case where a high-luminance light is being directed to the center pixel P 12 of FIG. 8 , but a light is hardly entered to the remaining pixels. The operation of the second pixel column is mainly described.
(1) First of all, in an FD-section reset period T 1 , with the two row selection pulses φROW 1 and φROW 2 being in the H level, pixel outputs of the two rows are coupled to the vertical signal line 32 , thereby configuring the differential input circuit. The pixel power supply VDD 2 of the second row is being set to the first clipping voltage VclipH. In this state, the two row reset pulses φRST 1 and φRST 2 are both set to the H level so that the voltage VFD 12 of the floating diffusion section FD 12 of the pixel P 12 in the first read row is fixed to the power supply voltage VDD, and the voltage VFD 22 of the floating diffusion section FD 22 of the pixel P 22 in the second row for generation of the clipping voltage is fixed to the first clipping voltage VclipH. With the voltages being fixed as such, the potential V 32 of the vertical signal line 32 becomes (VDD−VGS-M 312 ). In the CDS circuits 10 , the clamp pulse φCL and the sample hold pulse φSH are also set to the H level.
(2) In the next reset sampling period T 2 , the reset pulse φRST 2 in the second row is remained in the H level, and the reset pulse φRST 1 in the first row is set to the L level. In the pixel P 12 in the first row, the floating diffusion section FD 12 drops its voltage VFD 12 as shown in the drawing due to the leakage of charge or others from the photodiode PD as a result of the entering of the high-luminance light. On the other hand, because the reset pulse φRST 2 remains in the H level in the pixel P 22 in the second row for generation of the clipping voltage, the voltage VFD 22 of the floating diffusion section FD 22 remains fixed to the first clipping voltage VclipH. Accordingly, the potential V 32 (Rst) of the vertical signal 32 is clipped to (VclipH−VGS-M 322 ), thereby favorably preventing a black sun phenomenon from being caused due to the next differential processing to be executed by the CDS circuits 10 . Note here that the term of VGS-M 322 denotes the gate-source voltage of the amplification transistor M 322 of the pixel P 22 . At the end of the reset sampling period T 2 , the potential V 32 (Rst) (=VclipH−VGS-M 322 ) of the vertical signal line 32 is clamped with the clamp pulse φCL being set to the L level in the CDS circuits 10 .
(3) In the following signal transfer period T 3 , with the reset pulse φRST 2 of the clipping-voltage-generation pixel in the second row being remained in the H level, the transfer pulse φTR 1 in the first pixel row is set to the H level. This further reduces the voltage VFD 12 of the floating diffusion section FD 12 in the pixel P 12 in the first row (read row) by the storage charges of the photodiode PD. The pixel power supply VDD 2 of the clipping-voltage-generation pixel P 22 in the second row is changed to the second clipping voltage VclipL, and then the voltage VFD 22 of the floating diffusion section FD 22 of the pixel P 22 is changed and fixed to the second clipping voltage VclipL.
(4) In the following signal sampling period T 4 , with the reset pulse φRST 2 in the second pixel row being remained in the H level, the transfer pulse φTR 1 in the first pixel row is set to the L level. In this stage, the voltage VFD 12 of the floating diffusion section FD 12 in the pixel P 12 in the first row is reduced down to the level of causing highlight transverse stripe, but the potential V 32 (Sig) of the vertical signal line 32 is clipped to (VclipL−VGS-M 322 ) because the voltage VFD 22 of the floating diffusion section FD 22 of the clipping-voltage-generation pixel P 22 in the second row is being fixed to the second clipping voltage VclipL. This accordingly enables to prevent any possible variation of the current of the vertical signal line 32 , thereby being able to prevent the highlight transverse stripe phenomenon.
With the processing operation of the CDS circuits 10 , the potential difference of the vertical signal lines 31 to 33 , i.e., the difference between the reset potential and the optical-signal-reading potential after the transferring of the signal charge, is retained at the sample hold capacitor C 12 . The potential difference is then output, via the column selection transistors M 6 and the output amplifier 5 , as an image signal free from the black sun phenomenon and the highlight transverse stripe phenomenon. In the below, the operation is repeated similarly while changing the read rows and the clipping-voltage-generation rows so that the image signals of one frame can be derived.
As described above, in this embodiment, the potential V 32 (VFD 12 −VGS-M 312 ) of the vertical signal line 32 is being clipped to (VclipH−VGS-M 322 ) at the time of resetting [V 32 (Rst)]. Therefore, the reset level is never lower than that, thereby being able to prevent the occurrence of a black sun phenomenon. Moreover, as is being clipped to (VclipL−VGS-M 322 ) at the time of signal reading [V 32 (Sig)], the potential V 32 of the vertical signal line 32 is not reduced down to a value smaller than that. As such, the drain-source voltage of the bias transistor M 51 is not reduced down to a value outside of the range of operating the bias transistor M 51 so that the highlight transverse stripe phenomenon can be prevented from occurring. Moreover, because the pixel P 12 in the first row is in the same pixel section as the clipping-voltage-generation pixel P 22 in the second row, their amplification transistors M 312 and M 322 are of the same size and have the same characteristics, and their gate-source voltages VGS-M 312 and VGS-M 322 thus do not vary that much. Accordingly, any possible variation of the clipping voltage can be reduced, and the effect of preventing the black sun phenomenon and the highlight transverse stripe phenomenon can be invariably observed.
Embodiment 2
Described next is a second embodiment. In this embodiment, a plurality of (N) pixels are used for generating the clipping voltage with the aim to reduce any possible variation of the gate-source voltage of an amplification transistor in a clipping-voltage-generation pixel by substantially increasing the gate area thereof, i.e., the variation of the gate-source voltage is in proportion to 1/√{square root over ( )}N (where N is the gate area of the transistor). As such, any possible variation of the gate-source voltage can be reduced on a column basis, thereby being able to provide a higher precision to the value of the clipping voltage.
FIG. 10 shows the range of a pixel row of a plurality of pixels for use to generate the clipping voltage in the second embodiment. Exemplified in this example is a case of using the upper and lower portions of the transition area as an area for the row of generating the clipping voltage. FIG. 11 shows a specific exemplary circuit configuration diagram of the second embodiment, and therein, any component similar to or corresponding to that in the first embodiment of FIG. 8 is provided with the same reference numeral. In this embodiment, for simplicity, FIG. 10 shows only the portion of five pixels arranged in a column as a pixel section including a plurality of pixels arranged therein two dimensionally. The pixels P 11 , P 21 , P 31 , and P 41 in the first to fourth rows are each used for generation of the clipping voltage, and the pixel P 51 in the fifth row is used for signal reading.
In the second embodiment with such a configuration, the basic operation of reading the image signal free from the black sun phenomenon and the highlight transverse stripe phenomenon is the same as that in the first embodiment, and FIG. 12 shows the timing chart for illustrating the operation. As is known from this timing chart, the clipping-voltage-generation pixels P 11 to P 41 in the first to fourth rows are operated at the same timing, thereby generating the first and second clipping voltages VclipH and VclipL. In the reset sampling period, the potential V 31 of the vertical signal line 31 is clipped to [V 31 (Rst)=(VclipH−VGS-Mave)], and in the signal sampling period, is clipped to [V 31 (Sig)=(VclipL−VGS-Mave)], thereby preventing the black sun phenomenon and the highlight transverse stripe phenomenon from occurring. Note here that the term of VGS-Mave denotes the average value of the gate-source voltage of the amplification transistors M 311 to M 314 in the pixels when the four clipping-voltage-generation pixels P 11 to P 41 are used all at once to generate the clipping voltage.
In this case, the gates of the four amplification transistors of the pixels are coupled together, and this means the same as the gate area being increased. As described above, the variation of the gate-source voltage VGS is in proportion to 1/√{square root over ( )}N (where N is the gate area of the transistors, and in this embodiment, the same as the number of the rows N). Therefore, when the number of the pixel rows is increased for use to generate the clipping voltage, the possible variation of the gate-source voltage VGS is reduced in the potential of the vertical signal lines at the time of generation of the clipping voltage. In the case of this embodiment, because the four rows of pixels are used to generate the clipping voltage, the extent of the variation of the gate-source voltage VGS will be reduced to ½.
When the number of the pixel rows is increased for use to generate the clipping voltage, e.g., increased to 10 , this leads to 1/√{square root over ( )}(gate area×10) being approximately equal to 1/[3×√{square root over ( )}(gate area)]. The extent of the variation of the gate-source voltage of the transistors is usually ±30 mV, and thus the resulting variation will be reduced to about ⅓, i.e., 10 mV. When the number of the pixel rows is increased to 25 for use to generate the clipping voltage, for example, this leads to 1/√{square root over ( )}(gate area×25) being approximately equal to 1/[5×√{square root over ( )}(gate area)]. The extent of the variation thus will be reduced to about ⅕, i.e., 6 mV. Ideally, increasing the number of rows as such will leave only the variation of the pixel amplifiers, i.e., amplification transistors. Note here that when a plurality of pixel rows are used to generate the clipping voltage, the combination of the pixel rows may be changed as appropriate.
Embodiment 3
Described next is a third embodiment. As shown in the first and second embodiment, when a single or a plurality of pixel rows are used to generate the clipping voltage, the pixel line(s) may include any defective pixel causing abnormal output. If such a defective pixel is used to generate the clipping voltage, the resulting clipping voltage cannot be appropriate in value, thereby resulting in a possibility of failing to serve the clipping function at the potential of the vertical signal lines. In consideration thereof, in this embodiment, information about the position of such a defective pixel is stored in a memory in advance, and for the clipping operation, the pixel line including the defective pixel may not be used to generate the clipping voltage.
FIG. 13 shows the clipping-voltage-generation pixel rows in a pixel section, i.e., rows L 1 to Ln, and columns C 1 to Cm, and the pixel at the row L 2 and the column C 2 , and the pixel at the row Ln- 1 and the column Cm- 1 are both defective. In such a state, because the rows L 2 and Ln- 1 each include the defective pixel, if the rows L 2 and Ln- 1 are used as the pixel rows to generate the clipping voltage, the clipping voltage of the columns C 2 and Cm- 1 may be different in value from that of other rows due to the abnormal output of the defective pixels. Therefore, the rows L 2 and Ln- 1 each including a defective pixel are not used to generate the clipping voltage.
As such, in this embodiment, only normal pixels not causing abnormal output are used to generate the clipping voltage so that the clipping operation can be executed normally. Note here that the remaining basic operation in this embodiment is similar to that in the first or second embodiment, thereby being able to always prevent the black sun phenomenon and the highlight transverse stripe phenomenon from occurring without variation.
Embodiment 4
Described next is a fourth embodiment. In the solid-state imaging apparatus, there may be a case of reading only a part of the effective area in the pixel section, e.g., imaging with high definition. In such a mode with a reduced number of rows for signal reading, the number of rows not to be read is increased. In consideration thereof, in this embodiment, the resulting increased number of rows not to be read is used to generate the clipping voltage so that any possible variation of the gate-source voltage VGS can be reduced to a further extent in the amplification transistors at the time of generation of the clipping voltage.
FIG. 14 shows the pixel rows for use to generate the clipping voltage in a non-read area in the effective area of the pixel section in the mode with a reduced number of signal-read rows. In such an operation mode with a reduced number of signal-read rows, the non-read area in the effective area of the pixel section is used as a clipping-voltage-generation pixel row together with the transition area. This thus enables to reduce any possible variation of the gate-source voltage VGS in the amplification transistors at the potential of the vertical signal lines at the time of generation of the clipping voltage, thereby also being able to excellently prevent the black sun phenomenon and the highlight transverse stripe phenomenon from occurring. Note here that the basic operation of reading image signals free from the black sun phenomenon and the highlight transverse stripe phenomenon in this embodiment is the same as that in the second embodiment.
As described in the above embodiments, according to the first to fifth aspects of the invention, using an output of pixels included in the transition area disposed between the light-shielding area and the read area (effective area) in the pixel section, the output signal lines are clipped at the signal level of the pixels to prevent a highlight transverse stripe phenomenon from occurring. Accordingly, the resulting solid-state imaging apparatus becomes able to perform, with any possible variation being suppressed, the clipping operation of preventing a highlight transverse stripe phenomenon with no need to separately provide a clipping circuit.
According to the sixth to tenth aspects of the invention, an output of pixels included in the transition area disposed between the light-shielding area and the read area (effective area) in the pixel section is used to prevent a black sun phenomenon from occurring by clipping the reset level of the pixels to be output to the signal output lines. As such, the resulting solid-state imaging apparatus becomes able to perform, with any possible variation being suppressed, the clipping operation of preventing a black sun phenomenon with no need to separately provide a clipping circuit. | A solid-state imaging apparatus, comprising: a pixel section including a matrix having a plurality of pixels, each pixel including photoelectric conversion means, a storage section, transfer means, amplification means, and reset means, on a column basis, an output signal line whose one end is coupled to a constant-current source, and in which the area carrying thereon the matrix of the pixels includes a light-shielding area, a read area, and a transition area disposed between the light-shielding area and the read area; and control means for performing control to keep the potential difference between the one end and the other end of the constant-current source in a range with which the constant-current source can be operated by using the pixel signal to be output to the output signal line at the time of resetting the pixel of the transition area, when outputting the pixel signal corresponding to the incident light from the pixel of the read area. | 7 |
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Patent Application Ser. No. 60/649,193, filed Feb. 2, 2005, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to magnetic tracking and, in particular, to a distributed array environment that facilitates enhanced precision without the need for distortion compensation or mapping.
BACKGROUND OF THE INVENTION
[0003] One of the major drawbacks to utilizing magnetic trackers in such applications as aircraft simulators is the issue of distortion of the magnetic fields caused by the induction of eddy currents into nearby conducting metals. Since the use of good conductors such as aluminum is prevalent in the aircraft industry and other applications, the problem of distortion is a serious drawback to taking advantage of the reliability, maturity, speed, accuracy and compact size of magnetic trackers.
[0004] Methods for dealing with distortion have long been available. However, the cost of performing a precise mapping of the distortion so it can be compensated out of the tracker often results in several times the cost of the tracker itself; in addition, the asset being mapped is out of use for one to two weeks during the process. Consequently, there is a need for a system and method that can bypass the requirement for mapping in most situations.
[0005] Typical AC magnetic trackers operate with a magnetic field source in a fixed position. Fields from this source are coupled to one or more sensors which can then be tracked in the immediate volume nearby. Conceptually speaking, this is perhaps the easiest configuration to understand because all position and orientation (P&O) tracking results can be referenced to the source position. The addition of more sensors (e.g. to track hand motions as well as the head) is thus quite straightforward.
[0006] Theoretically, the calculations of P&O between source and sensor are entirely reciprocal such that a sensor, or sensors, could be held static while the field source(s) is moved about and tracked. The position and orientation of one of the sensors, or even an arbitrary point in the environment, can be used as the geometric reference point for all tracking measurements. The capability for doing this “reverse tracking” through a sensor reference point in an environment is taught in commonly assigned U.S. Provisional Patent Application Ser. No. 60/598,709, the entire content of which is incorporated herein by reference.
[0007] The AC magnetic tracker block diagram shown in FIG. 1 depicts how orthogonal coils in the source ( 1 ) couple signals to the orthogonal coils of a sensor ( 2 ). Orthogonality is not a strict requirement nor is it a limitation of a single source and/or a single sensor. The typical AC magnetic tracker has a single source and at least one sensor, but many more sensors typically are added. The processor ( 3 ) controls the tracking activity and reports out to a host computer the position and orientation of the sensor(s) relative to the source.
[0008] Reciprocity allows this process to be reversed to yield the source position relative to a sensor. Additional mathematical algorithms allow the use of multiple sensors and referencing all P&O results to either one of the sensors or to another location in the environment. These capabilities, and also accommodation of multiple sources as long as their operating frequencies are distinguishable, are taught in U.S. patent application Ser. Nos. 11/147,977 and 11/207,098, the entire content of each being incorporated herein by reference.
[0009] In general, prior-art AC magnetic trackers attempt to cover large areas, minimizing distortion effects with relatively little concern for high accuracy. Although it may be advantageous to minimize source-sensor coupling distance and use multiple sensor responses to participate in solutions, previous applications exhibit reasonable accuracy over an area much larger than possible to achieve signal coupling from a single reference point relative to a distant signal source, referencing the result to a distant reference sensor.
SUMMARY OF THE INVENTION
[0010] This invention broadly resides in magnetic tracking systems and methods that concentrate source(s)/sensor(s) in a compact region, thereby facilitating enhanced precision without the need for distortion compensation or mapping. According to the invention, several sensors can be placed in accurately known (or determined through algorithms within the tracker processor) locations so that a single small magnetic field source can be tracked by all of them simultaneously. This allows participation of all such results in determining one final P&O answer to do two things: 1) Improve tracking accuracy, and 2) Maintain close coupling relative to any nearby conductors that could cause eddy current field distortion.
[0011] In the preferred embodiment, an array of 3-axis sensors is used to track the position and orientation of a small 3-axis field source. This might be considered a ‘reverse’ tracking system compared to typical trackers which use a single source to provide tracking of multiple sensors. However, since the tracking process is entirely reciprocal, in alternative embodiments multiple sensors can be used to track a source(s). It also is possible, though less desirable, to use an array of distinct sources to a single sensor. The invention is also applicable to both AC and DC tracking systems, but if DC tracking is used, one can have multiple sensors reverse-tracking a single source but cannot have multiple DC source tracking even a single sensor because thay cannot be distinguished.
[0012] By virtue of the invention, an array of sensors can be employed to 1) Achieve high-gain, high-precision accuracy of a small field source, such as on a helmet, eyepiece display, hand tool, or surgeon's instrument; 2) Operate where source-sensor coupling remains small as the source navigates a region covered by an array of sensors, thereby virtually eliminating the effects of eddy current distortion without resorting to complex and expensive compensation procedures; 3) Automatically produce the best answer possible by algorithms that account for range and distortion indications to use the proper sensor measurements in the overall P&O result; and 4) Be less sensitive to interference within the helmet or other sub-system on which it may be mounted by generating signals rather than sensing very small ones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a depiction of a typical configuration of an AC magnetic tracker;
[0014] FIG. 2 shows source and sensors according to the invention; and
[0015] FIG. 3 shows possible motion box relationships.
DETAILED DESCRIPTION OF THE INVENTION
[0016] This invention broadly resides in magnetic tracking systems that concentrate source(s)/sensor(s) in a compact region, facilitating enhanced precision without the need for distortion compensation or mapping. In the preferred embodiment, multiple sensors are used to track a moving source. The use of multiple sensors merged into a single tracking solution improves accuracy well beyond that of an unmapped volume, and the distribution of several sensors allows operating in a reasonable range larger than would be the case with a single sensor, particularly when all sensors are within coupling range and contribute to the position and orientation (P&O) result.
[0017] The system, referred to as DARTT (Distributed ARray Tracking Technology), improves upon certain existing capabilities, including: 1) Establishing a single reference point for source tracking when using multiple sensors (U.S. patent application Ser. No. 11/147,977, the entire content of which is incorporated herein by reference) or multiple sources (U.S. patent application Ser. No. 11/207,098, the entire content of which is incorporated herein by reference) and 2) Locating for reference the various sensors when preparing the framework.
[0018] In contrast to existing arrangements, however, the invention concentrates the tracking source(s) and sensors in a compact region, achieving greater precision without distortion compensation. Source-sensor distances are kept short to minimize outside influences, and this is done with the lowest amount of signal possible. The ability to string several small sensors near an aviator's head in a simulator, for instance, allows the system to monitor a small signal source on his head/helmet.
[0019] The source to be tracked in the DARTT can be tethered or untethered (i.e., cabled or wireless battery operation). If tethered, the tracking system electronics unit is continuously in control of generated signal level, synchronization, calibration, etc. in the normal tracker fashion, the only change being the reversal of typical roles for source and sensor. If untethered, the signal source can be detected and located by the sensor(s) as described in U.S. patent application Ser. No. 11/147,977, incorporated herein by reference, which discusses wireless sources, and synchronized with sensor operation as taught in U.S. Provisional patent application Ser. No. 11/147,888 incorporated herein by reference, which describes synchronizing to non-coherent sources.
[0020] The most often used technology for 3D head/helmet tracking has been AC magnetics where a field source ( 1 ) couples signals to at least one sensor ( 2 ) (see FIG. 1 ). Use of a dipole field model allows producing both position and orientation (P&O) of the sensor with a single data sample. In actuality, the P&O is a relative computation between source and sensor such that reciprocity holds true and it makes no difference which device is being tracked from the other as a reference.
[0021] The arrangement in FIG. 2 shows a grouping of magnetic field sensors ( 10 ) arranged on a bracket above the user's helmet which contains a small field source ( 11 ). For convenience, a special cable ( 13 ) could combine all the sensor connections along a mounting post ( 12 ) for connection to the tracker system electronics unit (SEU). The mounting post is depicted as a simple rectangular bar without connections since each and every application will need a mounting post and attachments specifically designed for that application. Another small cable would need to be connected over the body of the user to drive the small source on the helmet, or a battery driven circuit module could be used independent of the SEU. The most preferred configuration would be to have it cabled to the SEU, which happens to have an advantage over typical applications where the sensor is on the helmet. Substitution of the source means that strong drive signals will go to the helmet, where various interfering signals typically are present, which is a decided advantage over a sensor conducting off the helmet very low level signals, which easily can be compromised.
[0022] When operating in a confined region device coil apertures could be a problem, but this is solved by using a source and sensors of small size, as shown in FIG. 2 . Although algorithms are readily available to approximate aperture effects, it is best to eliminate the problem where possible. Another minor item is the need to change the cockpit boresighting function, which aligns the helmet with other systems, from a sensor to a source, which can be handled quite easily mathematically in the tracker. Only two issues remain: 1) Combining the P&O results received from each sensor in the way (straight average, weighted based on range to source, etc.) that produces the most accurate composite answer, and 2) Determining the least number of sensors and their geometry for achieving the desired results.
[0023] Two effects come into play when combining P&O results and considering the range, r, separating a specific source-sensor pair: 1) The signal-to-noise ratio (SNR) in the signal coupling, which decreases by 1/r 3 , and 2) The effect of distortion which, for a given type and shape distorter, tends to nonlinearly affect the result when separation distance, d, becomes less than 2r (that is d<2r, or r>d/2). Because the overall DARTT concept is aimed squarely at minimizing the effects of distortion, the second item deserves considerable attention. The SNR argument is much easier to deal with and can be managed reliably by weighting the result of a particular source-sensor pair practically to zero when separation reaches a certain threshold (typically can be set to 12″-15″; 30 cm-38 cm for standard devices) unless all source-sensor pairs are past such a threshold, in which case all must be used in an attempt to minimize noise effects unless another criterion, such as distortion, dominates. Nevertheless, long range accuracy will suffer, but use of many sensor results can make this less severe.
[0024] Distortion effects typically starting at r>d/2 require more attention. Polhemus has developed an algorithm which we call a “distortion alarm” that can be put to use here. Consequently, a detailed description of how the distortion alarm works follows below. The P&O algorithm uses a dipole field model. As such, computations on the position vectors and the measurements collected should reconcile closely.
[0025] The distortion alarm (DA) consists of subtracting the value of the sensor signal matrix from the position measure, which should be zero in the ideal situation. As distortion is encountered, a growing difference becomes a measure of the growing uncertainty in the P&O result. Hence, a small threshold value can be set to determine if distortion is present. In equations,
| kRR T +I−S T S|=δ< distortion threshold,
where k=constant,
R=position vector, I=unity matrix, S=signal matrix,
[0029] | |signifies the Euclidian norm, and
T signifies matrix transpose.
[0031] Use of the DA in the DARTT algorithm for determining P&O of the small field source is as follows: 1) For the P&O solution of each source-sensor pair the answer can participate in the final P&O result only if the DA does not occur, and 2) If all solutions indicate distortion, then no final P&O result should be provided. This is analogous to tracking with optical techniques where no result can be given if the light is blocked.
[0032] The number of sensors in the DARTT array plus their geometry remains to be discussed. If two sensors are used and the range to them is the same, accuracy should be improved by the number of participating sensors. In this case, 1/√2=0.707 of the single sensor error. If three sensors under the same conditions, 1/√3=0.577. Four sensors would be 1/√4=0.5, again if all conditions are the same. Of course the case where all sensors in the array are at the same range is a rare situation. Nonetheless, the trend certainly is evident that one extra sensor can make a 30 percent improvement, two extra about 42 percent and three 50 percent, each additional sensor contributing less. However, the use of multiple sensors allows some extension in range so that in the worst case if all but one sensor in the array are out of range, then the worst accuracy performance would be that of a single source-sensor pair in the limit.
[0033] Perhaps this can be better understood by referring to FIG. 3 . The (A) motion box geometry ( 20 ) is aimed at a fore-aft emphasis where the DARTT sensors ( 21 ) are arranged in a simple line, yielding a motion box width of perhaps ±8″-10″. Here, the extension of range without distortion is the primary concern. The (B) motion box geometry ( 22 ) consumes more sensors but allows more side-to-side tracking. Here, range is extended but so, too, are contributions from multiple sensors to enhance tracking accuracy. The (C) motion box ( 23 ) is a realistic approach where only three sensors could yield good side-to-side motion and could add fore-aft space ( 24 ) by adding another DARTT sensor ( 25 ). This allows a reasonable size to the motion box for range but allows multiple sensors to participate in accuracy in the region where a source (and helmet) may be confined most of the time in a flight simulator. For a side-by-side cockpit motion box, (D) added to (C), it may be possible to share a sensor and not use the one shown at ( 27 ). Forward extension ( 28 ) could match the geometry in (C). Of course, the actual number of sensors used depends on accuracy and distortion tolerance goals. | Magnetic tracking systems and methods confine source(s)/sensor(s) to a compact region, thereby facilitating enhanced precision without the need for distortion compensation or mapping. Several sensors placed in accurately known (or determined through algorithms within the tracker processor) locations allow a single small magnetic field source to be tracked by all of them simultaneously. Such a configuration allows an operator's head to be tracked accurately, as in a flight simulator, where coupling between field source and sensors is kept short, thereby eliminating the need for distortion mapping. | 6 |
FIELD OF THE INVENTION
[0001] The present invention is related to identification and other types of media and more particularly to the application of security images to such media.
BACKGROUND OF THE INVENTION
[0002] Identification and other types of media such as credit cards increasingly require added security features. Security features include holograms which are presently applied over a foiled section. Application of a holographic image requires specialized machinery to create multicolored defractive images in a holographic relief pattern on a substrate.
[0003] One example of such a method is shown in U.S. Pat. No. 4,758,296 which discloses a method of making surface relief holograms wherein hot stamping foils are used for applying defractive or holographic anti-counterfeiting features to credit cards, identification cards, passports, secured documents, certificates and the like. The holographic relief pattern can be applied over a foil section which is typically hot stamped onto the card. Multicolored defractive images are composed from segments of the foil with regions of different color being formed by foils having different average spatial frequency.
[0004] U.S. Pat. Nos. 5,759,683 and 5,464,690 disclose a holographic article wherein an apparatus and process is used for hot stamping small areas of a composite sheet onto a document substrate in order to create a chip. A holographic image is then embossed over the chip.
[0005] U.S. Pat. No. 4,006,050 discloses a card produced by a xerography method. There, a press is used for transferring stamping foils and heat transfers onto a card. A die of the press may be textured or have an overall pattern to make forgery difficult. The die is used over a transfer sheet with an image carried thereon laid face downwards on the top of a plastic base or card to create the texture.
[0006] U.S. Pat. No. 4,933,120 teaches a technique and apparatus for printing a hologram directly on paper or a sheet of other material. The material or paper is sequentially passed through printing and hologram forming stations. This process requires the application of a thin layer of reflective material to the surface relief pattern so that light is reflected and defracted onto an image of the hologram.
[0007] The creation of holographic images is a relatively expensive method for producing security features on a card or other substrate, but they provide the best form of security because is they are relatively difficult to replicate. While other references suggest the use of hot stamped foils and heat transfers onto a card, these do not provide a relatively high level of security because of the relative ease with which they may be duplicated. What is needed is a security feature which simulates the level of security provided by a holographic image while being produceable by a relatively less costly method.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the invention to provide a relatively simple foil security feature for application on substrates such as credit cards, identification cards, passports, secured documents, certificates and the like. This and other objects are achieved by providing a security image on a substrate. The security image is formed by first stamping or otherwise transferring a first foil section on a substrate wherein the first foil section has a first sheen. A second foil is stamped or otherwise transferred over the first foil section in the form of an image or pattern. The second foil is of a different sheen than the first foil. Subsequent foils of differing sheens may optionally be applied over or adjacent to the second foil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention will now be described by way of example with reference to the accompanying figures of which:
[0010] [0010]FIG. 1 shows an exploded perspective view of an identification card having the security image of the present invention.
[0011] [0011]FIG. 2 shows a perspective view of successive transfer sections utilized in manufacturing the card of FIG. 1.
[0012] [0012]FIG. 3 shows a top view of a completed identification card of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The invention will first be described generally with reference to FIG. 1. It should be understood that while the invention will be described by the exemplary embodiment of an identification card, this invention may be utilized with any suitable substrate to create other media such as passports, secured documents, certificates and the like. A card 10 is shown in FIG. 1 having four major components. First, a substrate 20 is provided for receiving images, text, and security features on both or either of its major surfaces 22 , 24 . A first foil section 30 is applied on the first major surface 22 and a second or subsequent foil images 40 are applied over the first foil section 30 . The substrate 20 may be optionally laminated utilizing a laminant sleeve 50 .
[0014] Each of the major components will be described in greater detail with reference once again to FIG. 1. First, the substrate 20 may consist of known PVC materials, TESLIN, or other suitable substrates for creating an identification, credit card or other media. It should also be understood that the substrate 20 may include other materials such as paper or other plastics which may be utilized in creating passports, secured documents, certificates, tags or other media. The substrate 20 material is only limited to a group of materials which is suitable for applying a foil or foil transfer thereon. The substrate 20 has two major surfaces 22 , 24 . In this exemplary embodiment, a photo 26 , text 28 , a bar code or other security features may be printed or otherwise applied on the first major surface 22 by well known techniques. Similarly, a bar code, magnetic strip, text, or other images may be printed or otherwise applied on the second major surface 24 also by well known techniques which are suitable for the particular material selected for the substrate 20 .
[0015] The first foil section 30 is applied over the substrate 20 on one of the major surfaces 22 , 24 . Here, in FIG. 1, the first foil section 30 is shown as being applied on the first major surface 22 . This foil section 30 may be applied by a hot stamping or other transfer process which is suitable for the foil material selected. A typical foil material for use in this application is commercially available from API foils, or Crown Roll Leaf and sold under trade names Holografx™ and Holofoil®. It should be understood that while these are suitable foil materials, the invention is not limited to their use and any transferable foil material may be utilized. The first foil section 30 has a sheen which may be a high sheen to provide a high degree of light reflection from the surface thereof.
[0016] It should be understood that while a second foil image 40 will now be described, subsequent foil images may also be applied over either the first section 30 or over the second foil image 40 . Subsequent foil images may be applied utilizing foils of differing sheens to create contrast between layers.
[0017] A second foil image 40 is applied over the first foil section 30 by a similar heat stamping or transfer process. The second foil image 40 is also commercially available from API foils or Crown Roll Leaf as described above without limitation. The second foil image 40 takes a shape of an image, pattern, text, logo or insignia and is applied within the area of the first foil section 30 . The second foil image 40 is preferably of a different sheen than the foil section 30 and optimally of a lower sheen than the first foil section 30 in order to provide light reflective contrast therebetween.
[0018] The method of making the card 10 of FIG. 1 will now be described with reference to FIG. 2. The substrate 20 is supplied to various stations 60 , 70 , 80 along a continuous sheet 21 . The continuous sheet 21 is shown here as having a single row of cards 20 however the continuous sheet 21 may take various other matrix formats in the assembly process. The sheet 21 enters a first transfer station 60 wherein the first foil section 30 is applied. The first foil section 30 is supplied to the transfer station along a first continuous roll 32 . The transfer station 60 includes a die 62 extending from a press 64 . Depending upon the foil material, the die 62 may be heated in order to perform the transfer or may simply apply pressure to transfer the foil from the continuous roll 32 onto the substrate 20 . This die 62 is moved by the press 64 in the direction of the arrow P perpendicular to the direction of motion M of the substrate 20 . The die 62 is preferably a flat surface die to create the first foil section 30 in a desired location on the first major surface 22 of the substrate 20 . The substrate 20 then progresses in the direction M towards the second station 70 where a similar press 74 has a die 72 extending therefrom. The die 72 transfers foil material from a second continuous roll 42 to create the foil image 40 over the first foil section 30 on the first major surface 22 . This die 72 is different, however, in that it preferably comprises the shape of an image, text, pattern or logo according the requirements of the security features. The die 72 similarly may be heated or simply pressed over the roll 42 as required by the material for achieving appropriate transfer. The substrate 20 continues to move along the direction M toward a third station 80 wherein various text, images or other features may be applied by printing or other well known techniques. It should be understood by those reasonably skilled in the art that while application of these features have been shown here in three stations 60 , 70 , 80 on a first major surface 22 , this process is as equally applicable to the opposite major surface 24 of the substrate 20 . Also, additional stations may be added for applying subsequent foils as described above. After exiting the third station 80 , the substrate 20 may be separated into appropriate sized cards along perforations 26 . Optionally, those cards may then be laminated by well known techniques to apply a laminant 50 thereover as shown in FIG. 1.
[0019] The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents. | This and other objects are achieved by providing a security image on a substrate. The security image is formed by first stamping or otherwise transferring a first foil section on a substrate wherein the first foil section has a first sheen. A second and optionally subsequent foils are stamped or otherwise transferred over the first foil section in the form of an image or pattern. The second or subsequent foils are of a different sheen than the first foil. | 1 |
[0001] This application is based on and claims the priority of this inventor's Provisional Patent Application No. 61/692,291, Filed Aug. 23, 2012.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a structure and a method for constructing trough shaped solar concentrators. The structural elements and method of constructing concentrating solar trough collectors of this invention is intended to substantially reduce wind loading on these structures.
[0003] Commercial prior art trough shaped concentrators have had parabolic cross sections. If these concentrators are constructed with high concentration ratio on the receiving element they tend to be large structures. Parabolic trough structures with aperture widths of 20 to 30 feet are common in the Concentrated Solar Power, CSP, solar electric power generation industry. It is obvious that such large structures present large wind loads. Wind loading puts high demand on the support structures of these concentrators. Support for these large parabolic reflectors must be robust to maintain structural integrity during moderate to high wind. In addition, the reflector material and its support structure must be strong enough to prevent flexing of the reflector and resultant defocusing. This is a common problem for parabolic troughs in the CSP industry. Further, since most trough concentrators must track the suns' movement in at least 1 direction, wind loading imposes requirements for robust tracking mechanisms as well. Wind loading for trough shaped solar concentrators is thus a major problem which the present invention is designed to address and reduce substantially.
SUMMARY OF THE INVENTION
[0004] The present invention comprises a structural architecture and method for constructing trough shaped solar concentrators that substantially reduces wind loading on such structures. Particularly the present invention comprises a trough shaped concentrator with Fresnelised strip reflectors that are supported by an open lattice structure. The lattice support structure is made of horizontal support members, which also serve as the support members on which the Fresnel strip reflectors are mounted and vertical support members that serve to support the horizontal support members. The horizontal support members are spaced on the vertical support members such that there is space between them through which air can flow. The vertical support members are likewise spaced apart to allow air to flow through the lattice structure. In addition diagonal support members may be incorporated if structural stability dictates. Thus is created a trough concentrator that is open and allows wind to flow through it thus reducing wind loading on the structure. In addition, to further reduce wind loading, the surfaces of all support members that are not optical surfaces may be constructed with aerodynamic contours that part the wind and further reduce wind loading on the structure. The essence of this invention is thus a Fresnelised trough concentrator constructed of an open structural lattice that will substantially reduce wind loading compared to trough concentrators with solid continuous reflectors or backing.
[0005] While current commercial trough concentrators have all been parabolic troughs this inventor has recently shown (Pending patent application Ser. No. 13/337,206) a Fresnel trough concentrator incorporating flat Fresnel reflectors. It is to be noted that the current Open Architecture invention can be realized for Fresnel trough concentrators incorporating both, flat and curved, parabolic, Fresnel reflectors.
[0006] Further aspects of the invention will become apparent from consideration of the drawings and the ensuing description of preferred embodiments of the invention. A person skilled in the art will realize that other embodiments of the invention are possible and that the details of the invention can be modified in a number of respects, all without departing from the inventive concept. Thus, the following drawings and description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 a is a cross section of this inventors' prior invention of a Trough Shaped Fresnal Reflector Concentrator with flat Fresnel reflector strips and a flat V shaped backing.
[0008] FIG. 1 b shows the concentrator of FIG. 1 a with all but optical reflector elements removed and illustrates the Open Architecture concept of the present invention applied to the concentrator of FIG. 1 a.
[0009] FIG. 2 is a cross section of one side of a Trough Shaped Fresnel Reflector Concentrator with flat Fresnel reflector strips and equal vertical spacing between the Fresnel reflector strips illustrating the Open Architecture concept of the present invention.
[0010] FIGS. 3 a and b together illustrate an alternative version of the open architecture concept in which the open spaces are oriented horizontally relative to the trough central axis.
[0011] FIGS. 4 a and b together illustrate an alternative version of the open architecture concept in which the open spaces are oriented diagonally relative to the trough central axis.
[0012] FIG. 5 is a cross section of a Fresnelised Parabolic Trough Concentrator illustrating the Open Architecture concept of the present invention.
[0013] FIGS. 6 a, b and c show views of a lattice support structure for one side of the Fresnel Trough Concentrator shown in FIG. 1 b, comprising the Open Architecture of the present invention.
[0014] FIG. 6 a shows a back view. FIG. 6 b shows a side view. FIG. 6 c shows a top view of one of the vertical post support members.
[0015] FIG. 7 shows a rear view of a lattice support structure for the Fresnel Trough Concentrator shown in FIG. 2 and illustrating the Open Architecture structure of the present invention.
[0016] FIG. 8 shows a side view of the lattice support structure for the Fresnel Trough Concentrator shown in FIG. 2 and illustrating the Open Architecture structure of the present invention.
[0017] FIG. 9 shows a perspective view of the present invention showing the full Fresnel Trough Concentrator of FIG. 2 and illustrating the Open Architecture concept.
[0018] FIG. 10 shows a dynamic wind deflector that can be incorporated into the lattice support members of the Open Architecture structure.
DETAILED DESCRIPTION OF THE INVENTION
[0019] FIG. 1 a is a cross sectional representation of this inventors prior shown invention of a Trough Shaped Fresnel Reflector Solar Concentrator. It shows 1 the Fresnel step reflectors, 2 a receiver for the concentrated solar energy, 3 a flat V shaped backing for the trough and 4 vertical supports for the Fresnel step reflectors. The receiver 2 in this drawing is a triangular tube designed for mounting photovoltaic solar cells but could just as easily be a round tube designed for carrying a flowing fluid to be heated.
[0020] FIG. 1 b is a cross sectional representation of the Concentrator shown in FIG. 1 a with all the structural support elements of the Fresnel trough reflector removed and only the Fresnel reflectors remaining. Where the vertical supports for the Fresnel step reflectors 4 of FIG. 1 a were there are now open spaces 5 . If an open support structure is then constructed for this new Open Fresnel Trough Concentrator the open spaces 5 between the reflective Fresnel steps will provide open spaces for air to flow thru. This will reduce the wind loading on this new concentrator compared to the concentrator shown in FIG. 1 a. Examination of this figure shows that the open spaces 5 of this Fresnel reflector configuration are not all equal, some are larger than others. This is due to the Fresnel reflectors of this concentrator having originally been pegged to and constructed on an underlying linear V shaped structure. This uneven spacing between the Fresnel reflector strips is not optimum for reduction of wind loading.
[0021] FIG. 2 shows a cross-sectional representation of one side of a Fresnel Trough Concentrator with flat Fresnel step reflectors in which the spaces 5 between the Fresnel reflector strips are equal. This drawing demonstrates that the spaces 5 between the Fresnel reflectors can be made equal. Also, the dimension of the equal spaces 5 between the Fresnel reflectors in this representation was chosen arbitrarily, demonstrating that such a concentrator can be made with any spacing 5 desired between its Fresnel reflectors. In this drawing the spaces 5 between the Fresnel reflectors are vertical, that is to say a line drawn between the end of one reflector and the nearest end of the reflector immediately adjacent to it is parallel to the central axis of the trough. Creating vertical spaces does not increase the width of the trough structure compared to an equivalent trough without open spaces. However, it does increase the depth of the trough structure and consequently its overall size. Because the open spaces, in this configuration, are vertical and consequently parallel to the light coming into the trough, all the light entering the trough aperture is reflected by the Fresnel reflectors to the receiver and thus the optical efficiency is maintained and equal to an equivalent trough with no open spaces. When creating the open spaces between the Fresnel reflectors in a trough concentrator the designer must be cognizant of the increase in trough size, depth, and choose a spacing that achieves a balance between open spaces 5 that achieves good air passage thru the structure, reducing wind loading, and the consequent overall increase in trough size. FIG. 2 illustrates the basic concept of the present invention as a Fresnel reflector trough concentrator with open architecture designed to reduce wind loading on the trough structure. FIG. 2 shows a trough concentrator with the same receiver size and essentially the same concentration ratio as the trough concentrator of FIG. 1 b.
[0022] FIG. 3 a shows a cross-sectional representation of a trough concentrator with horizontal members 6 connecting the reflectors.
[0023] FIG. 3 b shows the trough of FIG. 3 a with the horizontal members removed to reveal horizontal open spaces 5 which constitutes an alternative embodiment of the present invention. It will be immediately obvious that the horizontal open spaces in this trough will increase its width compared to a trough without open spaces but not its depth or height. Also it will be obvious that some light entering the trough aperture will go through the open horizontal spaces thus reducing its optical efficiency relative to a trough without open horizontal spaces.
[0024] Since the reduction of wind loading on the trough structure is the purpose of this invention and this is accomplished by creating open spaces within the trough structure itself, consideration of the effect upon wind loading at different wind angles of attack to the structure must be considered. Because the trough needs to rotate to track the sun as it traverses the sky, the angle of attack of the wind to the trough will necessarily be quite variable because of this rotation as well as the natural variability of wind direction. In addition, the orientation of the open spaces within the trough structure needs to be considered relative to its effect on wind loading at different angles of attack. It appears intuitively obvious that horizontal spacing of the Fresnel reflectors would present less wind loading when the wind angle of attack is parallel to the central axis of the trough. Likewise, it appears intuitively obvious that vertical spacing of the reflectors would present less wind loading when the wind angle of attack is normal to or transverse of the central axis of the trough. Since the wind angle of attack will vary between both of these extreme directions as well as intermediate directions, a compromise or intermediate spacing of the Fresnel strip reflectors seems to suggest itself as a possible best solution for wind load reduction at all wind angle of attack directions.
[0025] FIG. 4 a shows a cross-sectional representation of a trough with a 45 degree member between the reflectors represented by dashed lines.
[0026] FIG. 4 b shows the trough of FIG. 4 a with the 45 degree diagonal members removed to reveal 45 degree open spaces 5 . In consideration of the above analysis of wind loading relative to wind angle of attack and the direction of the spacing of the Fresnel reflectors, it appears that this 45 degree open spacing between the reflectors may present the best overall reduction in wind loading for all wind angles of attack. Again, it is to be noted that with the 45 degree open spacing both the width and height or depth of the trough are increased relative to a closed trough with no open spaces. Also it is to be noted that with the 45 degree open spaces some of the light entering the trough aperture will pass through the 45 degree diagonal open spaces thus reducing this troughs optical efficiency relative to a closed solid trough. However, if sufficient wind load reduction can be achieved by creating horizontal or diagonal open spaces in the trough then the addition of trough width and the reduction of optical efficiency may be justified. These considerations await empirical testing.
[0027] FIG. 5 Shows a Fresnelised Parabolic Trough Concentrator showing a round tube receiver and illustrates that the concept of an Open Architecture Trough Concentrator can also be applied to and realized using curved Fresnel reflectors in a parabolic trough concentrator. Typically parabolic trough concentrators are continuous reflector troughs but for the purposes of reducing wind loading they can be made using curved Fresnel reflectors with spaces between them.
[0028] Curved parabolic reflector Fresnel troughs have some advantages as do flat reflector Fresnel troughs. Flat reflector Fresnel troughs have the advantage that they can more easily be made from inexpensive, readily available, off-the-shelf materials. Curved parabolic reflector Fresnel troughs have the advantage that the number and size of the Fresnel reflector sections in the trough can be chosen by the designer. This is a result of the focal nature of curved parabolic reflectors. The designer of an Open Architecture Parabolic concentrator will want to find the optimum balance between the number and size of the curved Fresnel reflectors and the number and size of the open spaces designed to reduce wind loading. Conversely, with flat Fresnel reflector trough concentrators the number and size of the Fresnel reflector steps is rigidly determined by the size of the receiver and the concentration ratio of the concentrator. This is because each flat Fresnel reflector step must fully illuminate the receiver and they do not have the benefit of a focal property. Designers of flat Fresnel reflector Open Architecture troughs still have the option of choosing the size of the spacing between their Fresnel reflector steps and optimizing them for maximum reduction of wind loading without unduly increasing the overall trough size.
[0029] The same lattice support structure with aerodynamic contours described in the following Figure descriptions for Open Architecture trough concentrators with flat Fresnel reflectors is also applicable to Open Architecture curved parabolic reflector concentrators.
[0030] FIG. 6 a shows a rear view of the lattice structure by which the Open Architecture concept of the present invention may be realized. FIG. 6 a shows the lattice structure of one side of the Open Architecture Fresnel Concentrator shown in FIG. 1 b. Here it is shown that the lattice structure minimally consists of horizontal members 8 and vertical posts 9 . Since the optical properties of the Fresnel Trough Concentrator require physical Fresnel reflector strips 1 , it makes sense that the horizontal members 8 of the lattice structure be incorporated with and serve as the backing structure for the reflective surfaces of the Fresnel Trough Concentrator. Vertical posts 9 are spaced apart and hold the horizontal members 8 in place and together they form a rigid lattice structure. If necessary, diagonal members 10 may be incorporated into the lattice structure to give it greater rigidity. The open spaces 5 necessary for air flow thru the lattice structure and wind loading reduction is established by the spacing of the horizontal members 8 mounted on the vertical posts 9 . In order to further reduce the wind loading on the lattice structure and the trough concentrator, aerodynamic contours 11 are incorporated as part of the surfaces of all structural elements (horizontal members 8 , vertical posts 9 and diagonal members 10 ) that are not optical surfaces. Thus the rear surfaces of the horizontal members 8 , whose front surfaces 1 are the Fresnel reflectors of the trough concentrator are constructed with aerodynamic surfaces 11 . Likewise, front, rear and side surfaces of the vertical posts 9 and the diagonal members 10 are constructed with aerodynamic surfaces 11 in order to be as passive to wind flow as possible.
[0031] FIG. 6 b shows a side view of the lattice structure, illustrating the aerodynamic contour 11 of the back side of the horizontal members 8 in cross section. Here it can be easily seen that the horizontal members 8 of the lattice structure serve a dual purpose; support for the Fresnel reflectors 1 of the trough concentrator and aerodynamic structural element.
[0032] FIG. 6 c shows a top view of one of the lattice vertical posts 9 illustrating their aerodynamic contours 11 in cross section. Here it can be seen that the portions of the vertical post 9 open and exposed to wind have aerodynamic contours 11 in all 4 directions.
[0033] FIG. 7 shows a rear view of the lattice structure of one side of the Open Architecture Fresnel Concentrator shown in FIG. 2 . Vertical posts 9 hold the horizontal members 8 in place with equal spacing 5 between them.
[0034] FIG. 8 shows a side view of the lattice structure of the concentrator of FIG. 2 . Here one possible geometric configuration of the vertical members, posts, 9 is represented as well as one possible aerodynamic contour 11 of the backs of the horizontal members 8 is shown. Again equal spaces 5 are shown between the horizontal members 8 and the Fresnel reflectors 1 .
[0035] FIG. 9 is a perspective view of one embodiment of the present invention. FIG. 9 shows a full trough version of the concentrator of FIG. 2 . Shown in this view are elements: 1 Fresnel reflector surfaces, 2 receiver, 5 equal open spaces between the horizontal members 8 and the reflectors 1 and 9 vertical member posts supporting the horizontal members 8 with equal spacing 5 between them.
[0036] FIG. 10 shows a dynamic version of the aerodynamic surfaces incorporated into the lattice support members of the Open Architecture structure of the present invention. Specifically, a self-adjusting aerodynamic pivoting wind deflector is shown. This structure consists of the lattice horizontal member 8 , which supports the Fresnel reflector 1 . Attached to the horizontal member 8 at a pivot 13 on the horizontal member 8 is a self-adjusting pivoting wind shield 12 . Because of its' shape and the pivot it is mounted on this wind shield will automatically pivot and orient itself in wind to have its' point facing into the wind and thus present its' aerodynamic surface into the, wind thus reducing wind loading. It is here to be noted that this structure may also be incorporated as dynamic aerodynamic surfaces for the lattice vertical post and diagonal support members.
[0037] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. | The present invention comprises an Open Architecture lattice geometric structure, aerodynamic provisions to that structure and methods to produce that structure for the manufacture of trough shaped solar concentrators having Fresnel reflector elements, such that the wind loading on these trough solar concentrators is substantially reduced compared to traditional trough concentrators with continuous panel structures. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
A Continuation-In-Part of U.S. Pat. No. 6,764,108, issued Jul. 20, 2004, which is a Continuation-In-Part of U.S. application Ser. No. 09/679,359, filed Oct. 5, 2000, now abandoned, which claims priority of Argentina P99 01 06162, filed Dec. 3, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an elongated assembly of hollow, torque transmitting pumping rods, used to selectively rotate a rotary pump located deep down hole in an oil well from a drive head located at the surface of the oil well A pumping rod assembly or sucker rod string is significantly distinguished in the art by the fact that such a string is not typically undergoing substantially free rotation like a drill pipe string, but rather is a true drive shaft that stores large amounts of reactive torque due to its large length, typically between 1,500 to 6,000 feet. The present invention comprises individual elements referred to herein as a “Hollow Sucker Rod” with at least a first end having a female thread and a “Connecting Element” which may be a separate “Nipple Connecting Element” with a pair of male threads or an integral male thread on a second, upset end of a Hollow Sucker Rod.
2. Description of the Related Art
Non-surging oil well extraction is normally achieved by means of pumping systems. The most common system uses an alternating pump located at the bottom of the well driven by a sucker rod string that connects the bottom of the well with the surface, where an alternating pumping machine to drive the string up and down is located. The sucker rods in the prior art, therefore, were designed originally to simply reciprocate up and down, and were are manufactured to API Specification 11B using solid steel bars with an upset end and a threaded end, each thread being of solid cylindrical section. The rods typically were connected one with the other by means of a cylindrical threaded coupling. More efficient pumping is performed when an oil extracting progressive cavity pump (PCP), or like rotary down hole pump is used. Among other advantages, PCP pumping of oil allows for higher oil extraction rates, reduced fatigue loads, reduction in wear on the inside of production tubing, and the ability to pump high viscosity and high solids component oils. PCP pumps are installed at the bottom of the well and driven from the surface by an electric motor connected to a speed-reducing gearbox by means of a string of torque transmitting rods. Traditionally standard API sucker rods are used to drive PCP pumps notwithstanding the fact that these rods have not been designed to transmit torsional loads. The transmission of torque by means of sucker rod strings presents the following disadvantages, i) low torque transmitting capacity, ii) high backspin iii) big stiffness differential between the connection and the rod body, all factors that enhance the possibility of fatigue failures. The reason for rupture on this type of conventional rod is failure due to fatigue in the junction zone of the head of the rod with the body of same due to the difference in structural rigidity between both parts—the body of the rod and the head of the rod.
For a given cross sectional area, torque transmission by a hollow rod with an annular cross section is more efficient than with a narrower, solid circular cross section. With the above mentioned concept in mind the prior art includes a hollow sucker rod that simply uses a standard API external cylindrical thread on a first end connector and an internal API thread on a second end connector, each connector being butt welded to a pipe body, which creates significant and abrupt change in section between the pipe body and each connection body. (See Grade D Hollow Sucker Rod, CPMEC Brochure, undated). The problem of sucker rod string backspin, and details of a drive head at the surface of an oil well and a rotary pump deep down hole in an oil well operation, which is the specific field of invention being addressed herein, can be found in Mills (U.S. Pat. No. 5,551,510), which is incorporated herein by reference.
Various thread and shoulder arrangements are discussed in the prior art with respect to joining together oil well drill pipe, well casing and tubing. See, for example, Pfeiffer et al. (U.S. Pat. No. 4, 955,644); Carstenson (U.S. Pat. No. 5,895,079), Gandy (U.S. Pat. No. 5,906,400), Mithoff (U.S. Pat. No. 262,086), Blose (U.S. Pat. No. 4,600,225), Watts (U.S. Pat. Nos. 5,427,418; 4,813,717; 4,750,761), Schock et al. (U.S. Pat. No. 6,030,004), and Hardy et al. (U.S. Pat. No. 3,054,628). The Watts patents imply that a pre-1986 API standard for strings of casing and tubing was a straight thread, with a turned down collar and that his improvement comprised a flush joint tubular connection with both tapered threads and a shoulder torque. Watts also refer to API standards for tubing and casing where triangular and buttress threads can be used with a torque shoulder. The 1990 patent to Pfeiffer et al, and the 1996 patent to Carstensen et al, in contrast, refer to a more current API standard (truncated triangular thread, connection using a torque shoulder) for strings of casing and tubing that appears to involve frusto-conical threads and shoulders. Carstensen et al at col 7, line 9+ include a discussion about how a particular conical gradient and length of a thread defines stress distribution results. Likewise, Pfeiffer et al at col 2, line 51+ say their threads are tapered and according to “API standards” with their improvement essentially only having to do with transitional dimensions. Hence, the problem addressed by Pfeiffer is an assembly of drill pipe sections where it apparently was critical to use a compatible and standard non-differential thread according to API standards, and also with no incomplete threads and no torque shoulder specification. The main features of the Pfeiffer thread appear to be symmetrical, truncated triangle threads (between 4 and 6 threads per inch, 60° flank angle) and a thread height that is the same for the male and female thread (between 1.42 and 3.75 mm). Also, there is identical nominal taper on male and female ends (between 0.125 and 0.25). Shock et al. illustrate a particular tool joint for drill pipe where the unexpected advantage for drill pipe applications derives from tapered threads that significantly must be very coarse (3 ½ threads per inch) and have equal angle (75°) thread flanks and elliptical root surfaces.
However, the different problem of backspin inherent in the intermittent operation of a sucker rod string when driving a PCP pump is not apparently addressed in any of these references. The design of the invention was made with certain specific constraints and requirements in mind.
First, the minimum diameter of the tubings on the inside of which the Hollow Rods must operate corresponds to API 2⅞″ tubing (inner diameter=62 mm) and API 3½″ tubing (inner diameter=74.2 mm). The oil extraction flow rate must be up to 500 cubic meters per day, maximum oil flow speed must be 4 meters per second. The above-mentioned values strongly restrict the geometry of the rods under design. Second, to ensure a Hollow Rod with a high yield torque so that maximum torque is transmitted to the PCP pump without damage to the Hollow Rod string. Third, to minimize and distribute stresses in the threaded sections. This requirement is met by using a particular conical thread, differential taper, low thread height and a conical bore in the sections under the threads. Fourth, the Hollow Sucker Rod must have good fatigue resistance. Fifth, to ensure low backspin, and high resistance to axial loads. Sixth, ease of make up and break out (assembly of mating threaded parts) must be ensured, and is by a tapered thread. Seventh, to ensure high resistance to unscrewing of the Hollow Sucker Rod due to backspin, or the counter-rotation of a sucker rod string when driving motor stops running and the pump acts as a motor. Eighth, to ensure high resistance to jump out of the Hollow Sucker Rod string (Hollow Rod parting at the threaded sections) by means of adequate thread profile and reverse angle on the torque shoulder. Ninth, to minimize head loss of the fluids that occasionally can be pumped on the inside of the Hollow Sucker Rod through the added advantage of a conical bore on the nipple. Tenth, to ensure connection sealabilty due to sealing at the torque shoulder, and also due to diametrical interference at the threads. Eleventh, a thread profile designed so as to optimize pipe wall thickness usage. Twelfth, to eliminate use of the welds due to susceptibility of welds to fatigue damage, sulphide stress cracking damage and also the higher costs of manufacturing. Thirteenth, when a fluid flows through the interior of the rod with reasonable speed, it produces early wear of the nipple and rod in the area where they connect (overlap), hence, a small seal was introduced at the ends of the nipple.
Fourteenth, to substantially increase the flow of fluid extracted, holes in the rod body were drilled to allow the fluid flowing through the interior of the rod.
A first object of the present invention is to provide an assembly of sucker pump rods and either separate threaded unions, or an integral union at the second end of each sucker rod, to activate PCP and like rotary type pumps, capable of transmitting greater torque than the solid pump rods described in the API 11 B Norm and also possessing good fatigue resistance. Additionally, the present invention seeks to define a threaded union for hollow rods that is significantly different from, and incompatible with, the standard for sucker rod assemblies as defined in the API 11 B Norm, yet still can easily be assembled. In fact the modified buttress thread is unique in that it is differential. For example, API Buttress Casing requires non-differential threads, with the taper for both a pipe and a coupling being 0.625 inches/inch of diameter. Likewise, API 8r casing and API 8r tubing both also require non-differential threads, with the taper for both a pipe and a coupling being 0.625 inches/inch of diameter. Still further, each of API Buttress Casing, API 8r casing and API 8r tubing do not employ any manner of torque shoulder.
A related object of the present invention is to provide an assembly of pump rods and unions with lesser tendency to uncoupling of the unions whenever “backspin” occurs, whether by accident or when intentionally provoked by the deactivation of the pump drive. The present invention surprisingly and significantly decreases the stored torsional energy in a sucker rod string. The stored energy in the string is inversely proportional to the diameter of the rod, and is directly proportional to the applied torque and the length of the string.
Another object of the invention is to provide for an assembly of sucker rods which are hollow and configured with a bore to permit passage of tools (sensors for control of the well) and/or allow interior circulation of fluids (injection of solvents and/or rust inhibitors).
Other objects of the present invention are to solve the corrosion-erosion probem, by a small seal introduced at the ends of the nipple, with a corresponding modification of the angle of the internal conical bore and to substantially increase the flow of fluid extracted, with holes in the rod body at extreme ends of the string.
SUMMARY OF THE INVENTION
The present invention addresses the foregoing needs in the art by providing a new type of Hollow Sucker Rod consisting essentially of a pipe central section, with or without an upset, with at least one internal or female conical thread at a first end having a thread vanishing on the inside of the rod and a conical external torque shoulder. That first end is configured to engage a corresponding external or male thread that is differential and also to abut against a conical torque shoulder on either another rod with an externally threaded integral Connecting Element as its second end, or one of the shoulders between the external threads of a separate Nipple Connecting Element. If separate Nipple Connecting Elements are used, then the sucker rod second end is always the same as the first end. If separate Nipple Connecting Element are not used, then the sucker rod second end is configured with an upset end having a male conical thread adapted to engage the first end of another Hollow Sucker Rod.
A Nipple Connecting Element consists essentially of a central cylindrical section with a pair of conical external torque shoulders. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string. The nipple preferably also has a wall section that increases towards the torque shoulders from each free end to increase fatigue resistance. In order to further optimize the stress distribution between the elements, a specific type of thread with a differential taper is used. The overall configuration ensures high shear strength, lowered stress concentration and a surprising resistance to storing reactive torque, which minimizes dangerous backspin when power to the sucker rod string is interrupted.
The Nipple Connecting Element member also has trapezoidal, non-symmetric male threads at each end or extreme, separated by a pair of shoulder engaging elements, but that male thread is differential as to the diametral taper of the female thread on at least the first end of a Hollow Sucker Rod. The threaded nipple and the rod can be joined with or without discontinuity of outer diameter. The ratio of the diameter of the union to the diameter of the rod may between 1 without discontinuity of diameters, to a maximum of 1.5. In this manner the mean value of the external diameter throughout the length of the string will always be greater to that of a solid rod with equivalent cross-sectional area mated to a conventional union means. Hence, for a given length of string and cross-sectional area, resistance to “backspin” will be greater in an assembly according to the present invention. The dimensions of the nipple also may be defined with a conical inner bore proximate the length of each threaded extreme, to further enhance an homogenous distribution of tensions throughout the length of each thread and in the central body portion of the Nipple Connecting Element. In this way it is possible to obtain a desired ratio of diameters of the threaded ending of the nipple with respect to the internal diameter, and a ratio of outside diameter of the nipple with respect to the internal diameter and an additional ratio between the external diameter of the nipple and the diameter of each threaded extreme.
In a first object of the present invention, the essential characteristic of a Hollow Sucker Rod is at least a first end of a tubular element threaded with a conical female thread which is configured as a Modified Buttress or SEC thread and vanishes on the inside of the tubular element, in combination with a conical frontal surface at an angle between 75° and 90°, known as a torque shoulder. The external diameter of the HSR 48×6 External Flush and the HSR 42×5 Upset embodiments comprise a tubular rod body element away from the ends being 48.8 mm or 42 mm and the external diameter of the tubular element in the upset end of a 42 mm rod being 50 mm. These dimensions are critical since sucker rods of that maximum diameter can fit within standard 2⅞ inch tubing (62 mm inside diameter). For 3½ inch tubing (74.2 mm inside diameter) the HSR 48×6 Upset, with a diameter at the upset end of 60.6 mm, can be used for maximum advantage. The thread shape is trapezoidal and non-symmetric, with a Diametrical taper in the threaded section. The Length of threads on at least the first end of the tubular element are incomplete due to vanishing of thread on the inside of the tubular element. There is an 83° angle (Beta) of the conical surface in the torque shoulder as shown in FIG. 2A . There are radii at the inner and outer tips of the torque shoulder. At the end of the threaded section a short cylindrical section on the inside of the threaded area transitions the threaded area to the bore of the tubular element.
In a first object of the present invention, the essential characteristic of a Nipple Connecting Element is a differential thread engagement on either side of a central section that is externally cylindrical with a larger cross-sectional area in the vicinity of the torque shoulder for surprisingly improved fatigue resistance. At either side of this central section external torque shoulders are located to mate with a torque shoulder on a first end of a Hollow Sucker Rod. The mean diameter and total cross-sectional area of the torque shoulder is maximized, to allow maximum torque handling.
In addition, either end of the nipple externally threaded is conical so to create a larger cross-sectional area in the vicinity of the torque shoulder and thereby surprisingly improve fatigue resistance. To achieve this advantage a narrowing conical inner bore starts proximate the free end of each threaded extreme and thereby defines an increasing wall thickness cross-section towards the central section of the nipple. The external diameter of the central section of the nipple is 50 mm or 60.6 mm and that central section may have a pair of machined diametrically opposite flat surfaces, to be engaged by a wrench during connection make up. The thread is a Modified Buttress thread, which creates a differential due to slightly different amounts of diametral thread taper on the rod and on the nipple. The thread shape also is trapezoidal and non-symmetric. All threads on the nipple are complete. A pair of conical surface act as torque shoulders with a conical frontal surface at an angle between 75° and 90°. There are radii at tips of the torque shoulder, both at an inner corner and an outer corner. Preferably, conical bores under each threaded section of the nipple are connected by a cylindrical bore to create a larger cross-sectional area in the immediate vicinity of the torque shoulder in order to surprisingly improve fatigue resistance.
The thread taper on the nipple and on the rod is slightly different (Differential Taper) to ensure optimal stress distribution. When the connection is made up the corresponding torque shoulders on the rod and on the nipple bear against each other so that a seal is obtained that precludes the seepage of pressurized fluids from the outside of the connection to the inside of said and vice-versa. This sealing effect is enhanced by the diametrical interference between the two mating threaded sections on the first end of the rod and on the nipple.
A fluid flowing through the interior of the rod with reasonable speed tends produce early wear of the nipple and rod in the area where they connect (overlap). This phenomenon can be attributed to the existence of an “stagnation area” where the fluids remains almost still (low velocity). To overcome that corrosion problem the invention includes modifications so that the “stagnation zone” does not exist any more and the fluid flows smoothly and with little turbulence. It is important to note that these modifications are small so that they do not alter significantly the stress distribution in the connection or the performance of the nipple.
In yet other set of embodiments, the objective is to substantially increase the flow of fluid extracted, through a further modification to a hollow sucker rod by drilling a series of holes in the rod at the two extremes of the string, i.e., at the ground level and at the bottom of the well.
A better understanding of these and other objects, features, and advantages of the present invention may be had by reference to the drawings and to the accompanying description, in which there are illustrated and described different embodiments of the invention. All of the embodiments are considered exemplary of parts of a preferred assembly embodiment, since any one of the illustrated male ends will successfully mate with any one of the illustrated female ends.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B , represent a Prior Art configuration of a conventional solid sucker rod as established in the API 11 B Norm specification.
FIGS. 2A , 2 B and 2 C respectively represent general configurations of a Hollow Sucker Rod first end, a Nipple Connecting Element, and an assembly of both elements according to a first embodiment of the invention, with a constant outer diameter.
FIG. 3A represents a general configuration of the assembly of a Hollow Sucker Rod having first and second female threaded ends and a Nipple Connecting Element according to a second embodiment of the invention, with an upset end, or an enlarged outer diameter.
FIG. 3B represents a general configuration of the assembly of a Hollow Sucker Rod having a first female threaded end and a second end with a male threaded end according to a third embodiment of the invention, with a constant outer diameter.
FIGS. 4A , 4 B and 4 C respectively represent an axial section view, a shoulder detail view and a cross-section view along Line 4 C— 4 C of a Nipple Connecting Element having first and second male threaded ends, according to a fourth embodiment of the invention, styled Hollow Rod 48×6 External Flush.
FIGS. 5A and 5B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod having a first female threaded end, according to the fourth embodiment of the invention.
FIGS. 6A , 6 B and 6 C respectively represent an axial section view, a cross-section view along Line 6 B— 6 B and a shoulder detail view of a Nipple Connecting Element having first and second male threaded ends, according to a fifth embodiment of the invention, styled Hollow Rod 42×5 External Upset.
FIGS. 7A and 7B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod having a first female threaded end, according to the fifth embodiment of the invention.
FIGS. 8A , 8 B and 8 C respectively represent an axial section view, a shoulder detail view and a cross-section view along Line 8 B— 8 B of a Nipple Connecting Element having first and second male threaded ends, according to a sixth embodiment of the invention, styled Hollow Rod 48.8×6 External Upset.
FIGS. 9A and 9B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod having a first female threaded end, according to the sixth embodiment of the invention.
FIG. 10A represents an axial section view and dimension detail view of a first female threaded end on a Hollow Sucker Rod showing the configuration of a trapezoidal, non-symmetric thread profile that is a Modified Buttress or SEC thread, according to the preferred embodiments of the invention.
FIG. 10B represents an axial section view and dimension detail view of a first male threaded end on a Nipple Connecting Element showing the configuration of a trapezoidal, non-symmetric thread profile that is a Modified Buttress or SEC thread, according to the preferred embodiments of the invention.
FIG. 11 illustrates an axial section view of an external flush joint, with Zone A indicating a stagnation zone.
FIG. 12 illustrates corrosion in a stagnation zone.
FIG. 13 illustrates an axial section view of a modified external flush joint, with a modified nipple.
FIG. 14 illustrates an axial section view of a modified nipple, as in FIG. 13 .
FIG. 15 illustrates an axial section view of a modified rod, as in FIG. 13 .
FIGS. 16A and 16B illustrate an axial and section view of one extreme end of a modified rod, according to a Configuration 1;
FIGS. 17A and 17B illustrate an axial and section view of one extreme end of a modified rod, according to a Configuration 2; and
FIGS. 18A and 18B illustrate an axial and section view of one extreme end of a modified rod, according to a Configuration 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A represents a common solid sucker rod with its conventional threaded first end or head with a cylindrical-type male thread. A large discontinuity between the head of the rod and the body of the rod can easily be seen. Diameters DC and DV, respectively. FIG. 1B is a schematic of the assembly of that solid pump rod with a conventional threaded union or collar according to the API 11 B Norm.
FIGS. 2A–2C respectively represent general configurations of a Hollow Sucker Rod first end, a Nipple Connecting Element, and an assembly of both elements according to a first embodiment of the invention, with a constant outer diameter. FIG. 2A gives references at the female extreme of the hollow rod according to the invention. It is also possible to observe the frustro-conical shape threaded surface in the interior of the rod that diminishes in the internal diameter thereof. FIG. 2B gives references at the nipple or union according to the present invention. The external thread of frustro-conical shape and the presence of two torque shoulders can also be seen. It is also possible to observe the varying of the nipple inner bore diameter with conical shape labeled “Option A”, as indicated by a broken line, which in turn creates a larger cross-sectional area in the vicinity of the torque should and surprisingly improves fatigue resistance.
FIG. 2C gives further references for the assembly of two hollow pump rods and one threaded union. It can be observed that the two female threads in the internal diameter of rod ( 3 . a and 3 . b ) are joined to the corresponding male ends ( 1 . a and 1 . b ) and how torque shoulders ( 2 . a and 2 . b ) are part of nipple ( 2 ). The union between the corresponding male and female extremes is accomplished by differential engagement of the frustro-conical shape of the threads ( 5 . a and 5 . b ). The fact that the thread shape is frustro-conical facilitates the initial setting of each piece and assembly of both parts. Shoulders located at the extreme free end surfaces of the first and second ends of the hollow rods ( 4 . a and 4 . b ) engage, in the assembled position, against a pair of corresponding torque shoulders formed on the nipple ( 2 . a and 2 . b ). Said contact planes form a torque shoulder angle (angle “Beta” see FIG. 2A ) with respect to the axis of the rod, which angle being between 75° and 90° and most preferably being 83°.
FIG. 2B shows in general geometry references for a connecting element as a separate nipple and specifically defines outside diameter (DEN), internal diameter (DIN) and the start diameter of the torque shoulder (DHT). The connecting element for the invention is characterized by the ratios of diameters according to the following table:
Range
Diameter Ratios
Min.
Max.
DHT/DEN
0.60
0.98
DIN/DEN
0.15
0.90
DIN/DHT
0.25
0.92
FIG. 2B also illustrates, by the broken line, a conical bore option, Option A, for the nipple inner bore configuration, which is preferred. FIG. 2A shows the hollow rod in the union zone with an outside diameter (DEVU) and an internal diameter of the rod at the extreme surfaces of the first and second ends corresponding to the end of the thread (DIFR). It also shows the outside diameter of the hollow rod (DEV) labeled as DEVU=DEV, because there is no upset end acting as the union. The ratio of the maximum external diameter (DEVU), either of a separate connector element or the upset type end of integral connector element union, to the external diameter of the rod (DEV), as illustrated at FIGS. 3A , 7 A and 9 A, is maintained within the following range:
1 ≤ DEVU DEV ≤ 1.5
Hence for a maximum fixed diameter, the mean polar momentum of the hollow rod and connector string is greater than that for a solid pump rod of equal cross section diameter. Transmitted rotation moment or torque is therefore greater in a hollow rod column than in a solid rod column. This is also a determining factor in the resistance to the “backspin” phenomenon or counter-rotation of the rod string. Additionally, the ratio between the starting diameter of the torque shoulder on the connecting element (DHT) and the internal diameter of the hollow rod at the thread free end (DIFR), is maintained, as follows:
1 ≤ DIFR DHT ≤ 1.1
FIG. 3A gives further references at the assembly in which the ratio of the maximum diameter of the union (DEVU) to the diameter of the body of the rod (DEV) is limited (1<DEVU/DEV≦1.5). FIG. 3B is a possible configuration of the invention in which the female thread is machined on an upset first end of the rod, while the opposite or second end is machined with a corresponding male thread, the two threads being complementary but differential in diametral taper to each other. This configuration will be referred to as an upset rod, or as an integral union version.
FIGS. 4–10 , inclusive, relate to preferred embodiments where a Hollow Sucker Rod comprises at least a first end of a tubular element threaded with a conical female thread which is configured as a Modified Buttress or SEC thread and which vanishes on the inside of the tubular element, in combination with a torque shoulder angle (Beta) of between 75° and 90°. The external diameter of the tubular element away from the ends being either 42 mm or 48.8 mm and the external diameter of the tubular element in the upset end, if present, being either 50 or 60.6 mm.
FIGS. 4A , 4 B and 4 C respectively represent an axial section view, a shoulder detail view and a cross-section view along Line 4 C— 4 C of a Nipple Connecting Element 402 with a flat 406 having first and second male threaded ends, 401 .and 401 . b , according to a fourth embodiment of the invention, styled Hollow Rod 48×6 External Flush. In FIG. 4A the values are a Modified SEC thread 405 . b, 8 threads per inch; DEN=48.8 mm; DIN=20 mm with an expansion to 26 mm over a length of 44 mm to the extreme end; DHT=39 mm; Beta=83°; overall length=158 mm; thread length=46 mm and central section length=50 mm. The shoulder detail 402 . a in FIG. 4B begins 4.61 mm after the thread, has an inner radius of 1.4 mm and an outer shoulder radius of 0.5 mm.
FIGS. 5A and 5B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod 403 having a first female threaded end 403 . a , according to the fourth embodiment of the invention. In FIG. 5A the values are a Modified SEC thread 405 . a, 8 threads per inch; DEV=48.8 mm; DIFR=41.4 mm; DIV=37 mm; Beta=83°. The shoulder detail 404 . a in FIG. 5B has a 30° transition at the thread and extends 4.5 mm; has an inner radius of 0.8 mm and an outer shoulder radius of 0.5 mm.
FIGS. 6A , 6 B and 6 C respectively represent an axial section view, a cross-section view along Line 6 B— 6 B and a shoulder detail view of a Nipple Connecting Element 502 with flat 506 and having first and second male threaded ends, 501 . a and 501 . b , according to a fifth embodiment of the invention, styled Hollow Rod 42×5 External Upset. In FIG. 6A the values are a Modified SEC thread 505 . b, 8 threads per inch; DEN=50 mm; DIN=17 mm with an expansion to 25.3 mm over a length of 44 mm to the extreme end; DHT=38.6 mm; Beta=83°; overall length=158 mm; thread length=46 mm and central section length=50 mm. The shoulder detail 502 . a in FIG. 6C begins 4.61 mm after the thread, has an inner radius of 1.4 mm and an outer shoulder radius of 0.5 mm.
FIGS. 7A and 7B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod 503 having a first female threaded end 503 . a , according to the fifth embodiment of the invention. In FIG. 7A the values are a Modified SEC thread 505 . a, 8 threads per inch; DEVU ranging from 50 mm to DEV=42 mm; DIFR=41 mm; DIV=36.4 mm with a transition at 15° to 30 mm starting at 55 mm from the free end and back to 32 mm over a maximum length of 150 mm; Beta=83°. The shoulder detail 504 . a in FIG. 7B has a 30° transition at the thread and extends 4.5 mm; has an inner radius of 0.8 mm and an outer shoulder radius of 0.5 mm.
FIGS. 8A , 8 B and 8 C respectively represent an axial section view, a shoulder detail view and a cross-section view along Line 8 B— 8 B of a Nipple Connecting Element 602 with flat 606 and having first and second male threaded ends, 601 . a and 601 . b , according to a sixth embodiment of the invention, styled Hollow Rod 48.8×6 External Upset. In FIG. 8A the values are a Modified SEC thread 605 . b, 8 threads per inch; DEN=60.6 mm; DIN=20 mm with an expansion to 33.6 mm over a length of 44 mm to the extreme end; DHT=47 mm; Beta=83°; overall length=158 mm; thread length=46 mm and central section length=50 mm. The shoulder detail 602 . a in FIG. 8C begins 4.61 mm after the thread, has an inner radius of 1.4 mm and an outer shoulder radius of 0.5 mm.
FIGS. 9A and 9B respectively represent an axial section view and a shoulder detail view of a Hollow Sucker Rod 603 having a first female threaded end 603 . a , according to the sixth embodiment of the invention. In FIG. 9A the values are a Modified SEC thread 605 . a, 8 threads per inch; DEVU ranging from 60.6 mm to DEV=48.8 mm; DIFR=49.4 mm; DIV=44.6 mm with a transition at 15° to 30 mm starting at 55 mm from the free end and back to 35.4 mm over a maximum length of 150 mm; Beta=83°. The shoulder detail 604 . a in FIG. 9B has a 30° transition at the thread and extends 4.5 mm; has an inner radius of 0.8 mm and an outer shoulder radius of 0.5 mm.
FIG. 10A represents an axial section view and dimension detail view of a first female threaded end on a Hollow Sucker Rod showing the configuration of a trapezoidal, non-symmetric thread profile that is a Modified Buttress or SEC thread, according to the rod first end preferred embodiment. The female thread shape of each Hollow Sucker Rod is trapezoidal and non-symmetric and is incomplete. The thread pitch is 8 threads per inch. The thread height is 1.016+0/−0.051 mm. The Diametrical taper in the threaded section is 0.1 mm/mm. The Length of threads on at least the first end of the tubular element is 44 mm., with part of the threads being incomplete due to vanishing of thread on the inside of the tubular element. The thread taper angle is 2° 51′ 45″; the tooth inner surface is 1.46 mm and the teeth spacing is 1.715 mm; the leading edge has a 4° taper or load flank angle and an inner radius of 0.152 mm while the trailing edge has a 8° taper and a larger inner radius of 0.558 mm. At the end of the threaded section a short cylindrical section on the inside of the threaded area transitions the threaded area to the bore of the hollow tubular element.
FIG. 10B represents an axial section view and dimension detail view of a first male threaded end on a Nipple Connecting Element showing the configuration of a trapezoidal, non-symmetric thread profile that is a Modified Buttress or SEC thread, according to the nipple first or second end preferred embodiment. The external diameter of the central section of each Nipple Connecting Element is 50 mm or 60.6 mm and the central section can present a pair of machined diametrically opposite flat surfaces, to be engaged by a wrench during connection make up. The male thread is a Modified Buttress thread and is complete across both ends of the nipple. The threaded section pitch is 8 threads per inch. The thread height lies between 1.016+0.051/−0 mm. The diametrical thread taper in the threaded area is 0.0976 mm/mm. The thread shape is trapezoidal and non-symmetric. The length of threads on each extreme of the nipple is 46 mm. All threads on the nipple are complete. The angle of the conical surface in the torque shoulder (Beta) is 83°. The radius at the tips of the torque shoulder is 1.4 mm for the internal radius and 0.5 mm for the external radius. There are preferred conical bores under each threaded section of the nipple, which are connected by a cylindrical bore. The thread taper angle is 2° 47′ 46″; the tooth inner surface is 1.587 mm and the teeth spacing is 1.588 mm; the trailing edge has a 4° taper or load flank angle and an outer radius of 0.152 mm while the leading edge has a 8° taper and a larger outer radius of 0.558 mm.
FIGS. 11 and 12 illustrate the corrosion problem when a fluid flows through the interior of the rod with reaonable speed. Early wear of the nipple and rod occurs in the area where they connect (overlap). This phenomenon can be attributed to the existence of an “stagnation area” where the fluids remains almost still (low velocity). See Zone A, in FIGS. 11 and 12 .
To solve the above mentioned problem the nipple and rod of the type shown in FIGS. 2A and 2B were modified. FIG. 11 illustrates such a hollow rod 48×6, external flush, with a stagnation area at Zone A and the resulting corrosion illustrated in a photographic section view, by FIG. 12 . A small seal was introduced at the ends of the nipple, with the corresponding modification of the angle of the internal conical bore (Zone B, C and D in FIGS. 13–15 ). With this modification the “stagnation zone” does not exist any more and the fluid flows smoothly and with little turbulence. It is important to note that these modifications are small so that they do not alter significantly the stress distribution in the connection, nor the performance of the product. Note that the illustrated modifications were done on the nipple and the rod ( FIGS. 13–15 ). FIG. 13 represents a slight variation of FIG. 11 . A modification is introduced to the existing Nipple, in terms of a small seal zone, in order to prevent the fluid (when flowing through the inside of the pipe) to remain in the “stagnation area” promoting erosion-corrosion.
The stress distribution on the nipple and rod are similar to the HR 48×6 External Flush illustrated by FIGS. 2A–2C and FIG. 11 .
The torque shoulder ( 701 b , FIGS. 13–14 ) is similar to that in FIG. 11 .
The nominal diameter and diametrical taper in the threaded section ( 702 b , FIGS. 13–14 ) are likewise similar to FIG. 11 .
The nipple threads are complete and the length of threads ( 703 b , FIGS. 13–14 ) is smaller, and different than shown in FIG. 11 . ( 703 a , FIG. 11 ).
There is an external cylindrical zone betwen the end of the nipple and the threaded section ( 704 b , FIGS. 13–14 ). The length is between 10 mm to 27 mm and the external diameter is 36.8 mm. This is different from FIG. 11 .
The end of the nipple works as a seal of the union ( 705 b , FIGS. 13–14 ). The thickness of the end of the nipple is 2 mm, which is different from FIG. 11 . ( 705 a , FIG. 11 ).
The bore of the nipple is conical in the extremes. The preferred angle is 8° 16′ ( 706 b , FIG. 14 ) and is different from FIG. 11 . (3° 46′; See 706 a , FIG. 11 )
The total length of the nipple ( 707 b , FIG. 14 ) is similar to FIG. 11 . ( 707 a , FIG. 11 )
The rod likewise has a torque shoulder ( 708 b , FIGS. 13 and 15 ). The dimensions of that shoulder are similar to the shoulder shown in FIG. 11 . Part of the threads on the pipe or rod end is incomplete due to vanishing of thread on inside of pipe ( 709 b , FIG. 15 ), which is similar to FIG. 11 . The nominal diameter and diametrical taper in the threaded section ( 710 b , FIGS. 13 and 15 ) are similar to FIG. 11 .
There is a seal inside of the rod, near the end of incomplete threads on the rod ( 711 b , FIGS. 13 and 15 ). While that seal may appear to be a second torque shoulder, it does not function as one, and has not been designed to sustain load. The thickness of the seal is between 0 to 1.7 mm and depends on the manufacturing tolerances of the pipe, and is different from the HR 48×6 External Flush version of FIG. 11 . The angle of seal inside of the rod is 90 degrees and the length of it from the end of the pipe is 55 mm ( 711 b and 712 b , FIGS. 13 and 15 ), which is different from FIG. 11 . After “make up” (service torque applied), the separation between the nipple and the rod) at Zone B ranges from about 0 to 0.6 mm ( 713 b , FIG. 13 ). The seal Zone B is lightly loaded and it does not transmit torque. It is used only as a seal and to promote a smooth flowing of the fluid.
FIGS. 16–18 illustrate another embodiment, where the objective is to substantially increase the flow of fluid extracted, through a further modification to the extreme ends of a hollow sucker rod string, of the type illustrated at FIGS. 2A–2C , FIG. 11 or FIG. 13 .
A series of holes were drilled in the rod's body at the two extremes (ground level and well bottom level) of the string. In this way, the fluid is allowed to flow also (usually it does through the annular region between the outer surface of the rod and the inner surface of the “tubing”) through the interior of the Hollow Rod. The holes pattern preferrably may be a Configuration 1 with 2 holes per transverse section, alternating at 90°, with a given longitudinal distance between sections ( FIGS. 16A , 16 B); a Configuration 2 with holes that follow an helicoidal path with a “separation”in the longitudinal direction, and angle between holes of different sections ( FIGS. 17A , 17 B); or a Configuration 3: Three holes per tranverse section with a given longitudinal distance ( FIGS. 18A , 18 B).
FIGS. 16 A,B illustrate one extreme end of hollow rod 803 with 2 holes, 804 , per transverse section, 180° apart, distributed in an alternate way, each set opposed at 90° to the adjacent set of holes with a given distance between sections, p ( FIGS. 16A and 16B ). The preferred hole diameter, Dh, is between 5 mm to 7 mm. The preferred longitudinal distance between sections, p, is between 50 to 100 mm. The preferred total (longitudinal) length of the zone at each extreme end that has such holes, L, is 3000 mm to 4000 mm, with the zone comprising between 62 to 162 holes.
FIGS. 17 A,B illustrate one extreme end of hollow rod 805 with 1 hole, 806 , per transverse section. The holes follow a helicoidal path, with a preferred longitudinal separation or pitch, p ( FIG. 17B ), and a rotation angle from one section to the following of 120°. ( FIGS. 17A and 17B ). The preferred hole diameter, Dh, is between 5 mm and 7 mm. The preferred longitudinal distance between sections, p, is between 25 to 50 mm. The preferred total (longitudinal) length of the zone at each extreme end that has such holes, L, is 3000 mm to 4000 mm, with the zone comprising between 61 to 161 holes.
FIGS. 18 A,B illustrate one extreme end of hollow rod 807 with 3 holes, 808 , per transverse section, each about 120° apart about the circumference, with a preferred longitudinal separation or pitch, p ( FIG. 18B ). The preferred hole diameter, Dh, is between 5 mm and 7 mm. The preferred longitudinal distance between sections, p, is between 50 to 100 mm. The preferred total (longitudinal) length of the zone at each extreme end that has such holes, L, is 3000 mm to 4000 mm, with the zone comprising between 93 to 243 holes.
Therefore, the Modified Nipple (with seal) of FIG. 13 produces smooth fluid flow and little turbulence, when a fluid flows though the inside of the pipe, in turn yielding good erosion-corrosion resistance at Zone B when fluid flows though the inside of the pipe. The nipple of FIG. 14 also is interchangeable with a nipple as in FIG. 11 .
Hence, for all preferred embodiments, there is a diametral or differential taper. For example the rod first end taper is 0.1 inches/inch, while the corresponding taper of the either nipple end is 0.0976 inches/inch. For all preferred embodiments, the angle of the conical surface in the torque shoulder (Beta) is preferably 83°. The radiuses at the tips of the torque shoulder are 0.8 mm for the internal radius and 0.5 mm for the external radius.
Likewise, for all preferred embodiments, the Connecting Element has a central section that is externally cylindrical. Close to the outer diameter of this central section external torque shoulders are located to mate with the torque shoulder on a first end of a Hollow Sucker Rod. Both extremes of a nipple are conical and externally threaded, and a conical inner bore proximate the length of each threaded extreme creates an advantageous combination of structure, to ensure an increasing cross-section of the nipple from each free end of the nipple towards the central section, and the torque shoulder locations.
While preferred embodiments of our invention have been shown and described, the invention is to be solely limited by the scope of the appended claims. | An elongated drive string assembly includes a plurality of hollow sucker rods and connecting elements between a drive head located at the surface of an oil well and a rotary pump located deep down in an oil well, with a series of holes at each end to substantially increase the flow of extracted fluid. Each hollow sucker rod has a first end with a torque shoulder, which engages a torque shoulder formed on a connecting element. The threads are frusto-conical, non-symmetrical threads with a differential diametral taper. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string. | 5 |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention concerns the presence and clinical significance of autoantibodies directed against the interferon-inducible gene IFI16 in patients with systemic sclerosis/scleroderma (SSc), systemic lupus erythematosus (SLE) and other autoimmune diseases.
BACKGROUND OF THE INVENTION
[0002] A family of interferon (IFN)-inducible genes, designated HIN200 in the human and Ifi200 in the murine species, encodes evolutionarily related human (IFI16, IFIX, MNDA, and AIM2) and murine proteins (p202, p203, p204, p205/D3) (1, 2). The IFI16 (Pubmed Accession No. NP — 005522), p202, and p204 nuclear phosphoproteins participate in the inhibition of cell cycle progression, modulation of differentiation, and cell survival. Gene expression analyses in congenic mice have identified p202 as a candidate gene for lupus susceptibility (3).
[0003] In 1994 Seelig et al. (4) reported the presence of anti-IFI16 antibodies in 29% of sera obtained from systemic lupus erythematosus (SLE) patients and recently Uchida et al. (5) in up to 70% of patients suffering from both primary and secondary Sjögren's syndrome (SjS). Lower prevalence has been reported in other systemic autoimmune diseases such as rheumatoid arthritis (RA) (0-13%) and scleroderma/polymyositis overlap syndrome (3%) (4, 5). However, the studies on SjS and RA enrolled small series of patients and no data are available on the presence of these autoantibodies in another frequent systemic autoimmune disease such as scleroderma (SSc).
[0004] Moreover, IFI16 expression in target tissues of the autoimmune process (i.e. the salivary glands) was described (5). This finding raises the possibility that a local tissue expression (or even up-regulation) can be pivotal in triggering an autoimmune response against this protein. Interestingly, physiological IFI16 expression was found in vascular endothelial cells and in stratified squamous epithelia such as skin (6). Both these tissues are targets for main SLE clinical manifestations (7). The present inventors looked at IFI16 expression in the lesional skin from SLE patients in order to investigate whether an enhanced IFI16 expression might be associated with the occurrence of autoantibodies directed against it. Since an increased serum levels of anti-IFI16 antibodies was also observed in SSc patients, the present inventors extended the study to SSc skin biopsies as well.
SUMMARY OF THE INVENTION
[0005] The present invention relates to the expression of IFI16 in skin biopsy specimens from SSc and SLE patients. Levels of autoantibodies against IFI16 were determined by enzyme-linked immunosorbent assay (ELISA) in serum samples from 82 SSc and 100 SLE patients. Other autoimmune diseases (primary Sjögren's syndrome (SjS), rheumatoid arthritis (RA) and chronic urticaria (CU) were also examined.
[0006] The first aim of the present invention is to evaluate the presence and the titers of anti-IFI16 autoantibodies in a larger number of SjS, RA as well as in SSc patients and controls, and to partially characterize their antigenic specificity.
[0007] Object of the present invention is the provision of evidence that an IFN-inducible gene, IFI16, is involved in the pathophysiological mechanisms of connective tissue disorders such as SSc. More specifically, an object of the present invention is the provision of differential diagnosis methods for scleroderma, and, in particular, a novel tool in the differential diagnosis of lc-SSc (limited cutaneous form of scleroderma) from dc-SSc (diffused cutaneous form of scleroderma).
[0008] According to the present invention, said objects are achieved thanks to the solution having the characteristics referred to specifically in the ensuing claims. The claims form integral part of the technical teaching herein provided in relation to the present invention.
[0009] According to the present invention, said objects are achieved by means of the use of IFI16 protein, fragments or peptides thereof, wherein autoantibodies against IFI16 protein fragments or peptides thereof are detected. In a preferred embodiment, the diagnosis is based on the detection by an immunoassay (like for example ELISA, RIA, immunofluorescence or immunohistochemistry assay) of a higher level of autoantibodies against IFI16 protein, fragments or peptides thereof in the subject as compared to the normal level of these autoantibodies and/or to a level of these autoantibodies in patients suffering of a diffused cutaneous form of scleroderma (dc-SSc).
[0010] The differential diagnosis method according to a preferred embodiment of the present invention comprises:
a. obtaining a sample from a patient; b. contacting the sample with an antigen comprising IFI16 protein, fragments or peptides thereof to form a complex of the autoantibody and the antigen; c. detecting the presence of the complex autoantibody-antigen.
[0014] According to a preferred embodiment, the antigen of human, animal, synthetic or recombinant origin is bound to a solid carrier and the detection is performed using an anti-human IgG antibody, preferably conjugated to a detectable marker. The detectable marker is preferably selected from horseradish peroxidase, alkaline phosphatase, biotin or fluorescent dyes. The sample can be selected from whole blood, serum, plasma, saliva, tears, sweat, synovial fluid.
[0015] The present invention is also directed to a kit for the determination of anti-IFI16 autoantibodies in a sample preferably comprising a plate of wells having bound thereto IFI16 protein, fragments or peptides thereof and a detection reagent.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention will now be described in detail in relation to some preferred embodiments by way of non-limiting examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 . Increased expression of IFI16 in SLE and SSc lesions compared with skin from healthy controls. Expression of IFI16 in skin from healthy control (A), SLE lesion (B) and SSc lesion (C) (Original magnification×10). D, Enlarged section of derma from Panel C showing IFI16 staining in inflammatory cells (Original magnification ×20).
[0018] FIG. 2 . A, IgG titers against human recombinant IFI16 in patients with SSc (82), SLE (100), primary SjS (20), RA (50), CU (38) and HCV infection (40) and from healthy controls (80). Boxes show values within 25 th and 75 th percentiles, the horizontal bar represents the median, 80% of values are between the extremities of the vertical bars (10 th -90 th percentiles), and extreme values are represented by individual symbols. Differences between the groups have been evaluated by one-way ANOVA and Bonferroni Multiple Comparisons tests after logarithmic transformation. Values under the boxes represent the percentage of subjects with IgG titers above the cut off value, calculated at the 95 th percentile of the control population. Statistical significance: *p<0.001 vs controls. B, IgG titers against human recombinant IFI16 in patients with lc-SSc (57), dc-SSc (25), and healthy controls (80). Graphical representation and statistical analysis as in panel A. Statistical significance: * p=0.02 vs dc-SSc and controls.
[0019] FIG. 3 . A, Schematic representation of IFI16 and a series of recombinant IFI16 fragments. The two HIN200 domains (domain a and domain b) are indicated. Recombinant peptides corresponding to IFI16 aa 1-204 (IFI16 N-term) and aa 525-726 (IFI16 C-term) are indicated by a box. B, Reactivity to full length IFI16 by immunoblotting. Recombinant IFI16 (IFI16) or control peptide (pET30a) were separated by SDS-PAGE, transferred to nitrocellulose membranes and then incubated with 1:100 dilution of patients sera that were positive (lanes 1-12, with decreasing titers) or negative (lanes 13-14) using ELISA. C, Reactivity to IFI16 N-terminal (IFI16 N-term), C-terminal (IFI16 C-term) fragments or control peptide (pET30a). Nitrocellulose membranes with transferred recombinant proteins were incubated with patients sera that were reactive using immunoblotting to full length IFI16.
[0020] FIG. 4 . IgG titers against human recombinant IFI16 in patients with multiple sclerosis (MS, N=163) and healthy individuals (CTRL, N=64) as normal controls examined by ELISA with recombinant IFI16 protein. The horizontal bar represents the median.
[0021] The present inventors showed, for the first time, enhanced expression levels of the interferon-inducible protein IFI16 in the epidermis and in the dermal inflammatory infiltrate from both SLE and SSc lesions by immunohistochemistry. Additionally, the present inventors confirmed that anti-IFI16 autoantibody titers above the 95 th percentile of the controls are significantly elevated in patients with SLE and SjS, but not in those with other autoimmune diseases compared with controls. Interestingly, the present inventors found comparable prevalence of these autoantibodies in SSc as well. Furthermore, the association of anti-IFI16 autoantibody levels in SSc patients with a range of clinical and laboratory parameters was assessed by univariate analysis. The results obtained demonstrated that anti-IFI16 autoreactivity was not associated with either disease duration or disease severity, but with the limited cutaneous form of SSc (lc-SSc).
[0022] IFI16 expression was, in fact, greatly increased and found to be ubiquitously expressed in all layers of the epidermis and in the dermal inflammatory infiltrate in the lesional skin from both SLE and SSc patients. Patients with SLE, SjS and SSc exhibited significantly (one-way ANOVA p<0.0001) higher anti-IFI16 antibody levels of the IgG isotype than normal controls (SLE p<0.002, SjS p<0.001 and SSc p<0.0005, respectively). Anti-IFI16 titers above the 95 th percentile of the controls were observed in 26% of SLE, 50% of SjS and 21% of SSc respectively. By contrast, anti-IFI16 prevalence was 4% in RA, 5% in CU and 10% in HCV patients respectively.
[0023] The most striking data came from logistic regression analysis of the three serological autoimmune markers (anti-IFI16, anti-centromere and anti-topoisomerase I autoantibodies), strongly associated with the cutaneous form of SSc in the patients. This analysis showed that all three serological markers investigated were independent predictors of the cutaneous form of scleroderma, and their combination was able to explain 62% of the associated variability. Without being bound to any specific theory, the present inventors believe that IFI16 reactivity in patient with SSc is an important clue to the development of lc-SSc in anti-centromere and anti-topoisomerase I negative patients. In addition, the finding of anti-IFI16 positivity allowed the present inventors to detect lc-SSc patients among the subgroup negative for both anti-centromere and anti-topoisomerase I reactivity, indicating that determination of IFI16 reactivity in patient with SSc is a valuable tool for the differential diagnosis of lc-SSc in the double negative patients.
[0024] Prominent IFI16 expression has been seen in vascular endothelial cells and in stratified squamous epithelia such as skin. Its expression is normally restricted to the basal proliferative layer, suggesting a possible role in the control of skin homeostasis. Transduction of IFI16 into the human umbilical vein endothelial cells (HUVEC) by recombinant viruses efficiently suppressed the formation of capillary-like structures in vitro and cell-cycle progression associated with cell death (8). In addition, type I IFN released by plasmacytoid dendritic cells accumulated in cutaneous SLE lesions mediates inflammation and expression of interferon-inducible genes.
[0025] The present invention shows, then, that IFI16 is expressed to a higher level in SSc and SLE lesions in both epithelial and inflammatory cells, and autoantibody titers against it are significantly elevated in both diseases.
[0026] Thus, the disease model the present inventors propose is: i) IFI16 expression in lesional skin is enhanced by local type I IFN production or other pro-inflammatory stimuli; ii) IFI16 release, as a consequence of increased cell death, leads to the breakdown in tolerance to this self-antigen as confirmed by the generation of specific anti-IFI16 autoantibodies; iii) an additional pathogenic role of IFI16 is suggested by the observation that its endothelial expression triggers apoptosis, up-regulates the expression of genes encoding adhesion molecules (ICAM-1, E-selectin) and chemokines (IL-8, MCP-1) (S.L., unpublished data) and efficiently suppresses formation of capillary-like structures in vitro.
[0027] Finally, although the root causes of these autoimmune diseases are not yet known, with this disease model the present inventors contribute, and advance, the understanding of the cell and molecular mechanisms that impact on, and underlie, SSc and SLE. Moreover, antibody titer against IFI16 protein is an important serologic marker for the laboratory testing for the differential diagnosis of the limited cutaneous form of SSc.
[0028] Materials and Methods
[0029] Patients and Controls
[0030] 290 patients were included in this study, classified as follows: 100 SLE, 20 primary SjS, 82 SSc, RA, 38 CU and 163 MS. Sera from 80 sex and age matched healthy subjects were collected from blood banks and represented the control group. 40 patients with chronic HCV infection (kindly provided by Dr. Mario Pirisi, University of Piemonte Orientale, Novara) were also included as additional controls. SSc and primary SjS sera were from Spedali Civili, Brescia. SLE, RA and CU sera were obtained from Istituto Auxologico Italiano, Milan.
[0031] All SSc patients (73 women and 9 men, age 21-80, mean age 57) were classified as lc-SSc or dc-SSc according to the criteria of LeRoy et al (9). Patients were regularly assessed using a published consensus core set of variables (10). Disease severity was assessed using the preliminary Medsger scale (11). The most severe involvement was considered for a global severity score. Disability index was evaluated by Health Assessment Questionnaire (HAQ) (12).
[0032] Skin biopsies from 6 patients with SSc and 8 patients with SLE were available for immunohistochemistry. They were all taken for diagnostic purposes in stages of active skin disease. Control biopsies were taken from unaffected skin of patients undergoing surgery.
[0033] Informed consent for participating in this study was obtained from all donors.
[0034] Recombinant Proteins
[0035] The entire coding sequence of the b isoform of human IFI16 (SEQ ID. No.:1, HIStagged IFI16; MHHHHHHSSGLVPRGSGMKETAAAKFERQHMDSPDLGTDDDDKAMADIGSSLMSV KMGKKYKNIVLLKGLEVINDYHFRMVKSLLSNDLKLNLKMREEYDKIQIADLMEE KFRGDAGLGKLIKIFEDIPTLEDLAETLKKEKLKVKGPALSRKRKKEVDATSPAP STSSTVKTEGAEATPGAQKRKKSTKEKAGPKGSKVSEEQTQPPSPAGAGMSTAMG RSPSPKTSLSAPPNTSSTENPKTVAKCQVTPRRNVLQKRPVIVKVLSTTKPFEYE TPEMEKKIMFHATVATQTQFFHVKVLNTSLKEKFNGKKIIIISDYLEYDSLLEVN EESTVSEAGPNQTFEVPNKIINRAKETLKIDILHKQASGNIVYGVFMLHKKTVNQ KTTIYEIQDDRGKMDVVGTGQCHNIPCEEGDKLQLFCFRLRKKNQMSKLISEMHS FIQIKKKTNPRNNDPKSMKLPQEQRQLPYPSEASTTFPESHLRTPQMPPTTPSSS FFTKKSEDTISKMNDFMRMQILKEGSHFPGPFMTSIGPAESHPHTPQMPPSTPSS SFLTTLKPRLKTEPEEVSIEDSAQSDLKEVMVLNATESFVYEPKEQKKMFHATVA TENEVFRVKVFNIDLKEKFTPKKIIAIANYVCRNGFLEVYPFTLVADVNADRNME IPKGLIRSASVTPKINQLCSQTKGSFVNGVFEVHKKNVRGEFTYYEIQDNTGKME VVVHGRLTTINCEEGDKLKLTCFELAPKSGNTGELRSVIHSHIKVIKTRKNKKDI LNPDSSMETSPDFFF) was subcloned from pBluescript in the pET30a expression vector (Novagen, Madison, USA), containing an N-terminal histidine tag. The sequences encoding N-terminal (SEQ ID No.:2, HIStagged-IFI16 N-term, amino acid residues 1-200, MHHHHHHSSGLVPRGSGMKETAAAKFERQHMDSPDLGTDDDDKAMADIGSLMSVK MGKKYKNIVLLKGLEVINDYHFRMVKSLLSNDLKLNLKMREEYDKIQIADLMEEK FRGDAGLGKLIKIFEDIPTLEDLAETLKKEKLKVKGPALSRKRKKEVDATSPAPS TSSTVKTEGAEATPGAQKRKKSTKEKAGPKGSKVSEEQTQPPSPAGAGMSTAMGR SPSPKTSLSAPPNTSSTENPKTVAKCQVTPRRNVL) or C-terminal (IFI16 C-term, residues 525-729, (SEQ ID No.:3 MHHHHHHSSGLVPRGSGMKETAAAKFERQHMDSPDLGTDDDDKAMADIGSMVLNA TESFVYEPKEQKKMFHATVATENEVFRVKVFNIDLKEKFTPKKIIAIANYVCRNG FLEVYPFTLVADVNADRNMEIPKGLIRSASVTPKINQLCSQTKGSFVNGVFEVHK KNVRGEFTYYEIQDNTGKMEVVVHGRLTTINCEEGDKLKLTCFELAPKSGNTGEL RSVIHSHIKVIKTRKNKKDILNPDSSMETSPDFFF) fragments of IFI16 were amplified by PCR and cloned in frame in the pET30a vector. Expression and affinity purification were performed following standard procedures. The purity of the proteins was assessed by Coomassie blue staining following 10% sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). As negative controls for ELISA and immunoblotting, the polypeptide encoded by the pET30a empty vector (SEQ ID No.:4; control peptide, MHHHHHHSSGLVPRGSGMKETAAAKFERQHMDSPDLGTDDDDKAMAD IGSEFELRRQACGRTRAPPPPPLRSGC) was expressed and purified with the same protocol.
[0036] Immunoblotting and Immunohistology
[0037] 250 ng of recombinant IFI16 (SEQ ID No.:1), IFI16-N-term (SEQ ID No.:2), IFI16 C-term (SEQ ID No.:3) or control peptide (SEQ ID No.:4) were separated using SDS-PAGE under reducing conditions and transferred to nitrocellulose membranes. The membranes were blocked in 3% Top Block (Fluka, St. Louis, USA) and then incubated with 1:100 dilution of the patients sera. After washing, the membranes were incubated with horse radish peroxidase (HRP)-conjugated rabbit anti-human IgG (DakoCytomation, Glostrup, Denmark). The immunocomplexes were detected by enhanced chemiluminescence (ECL, GE Healthcare) and signals acquired with Versadoc3000 (Bio-Rad Laboratories Inc., Hercules, USA). After stripping, the membranes were reprobed with anti-IFI16 C-terminal rabbit polyclonal antibody (13) or anti-IFI16 N-terminal mouse monoclonal antibody (Santa Cruz Biotechnology, Santa Cruz, USA) to confirm the presence of the recombinant proteins.
[0038] Immunohistochemical analysis for IFI16 expression was performed on sections from paraffin-embedded tissues placed on silane-coated glass slides as previously described (6).
[0039] Determination of Antibody Titers Towards Human Recombinant IFI16 by ELISA
[0040] Polystyrene microwell plates for enzyme-linked immunoabsorbent assay (ELISA) (Nunc-Immuno Maxi-Sorp, Nunc, Roskilde, Denmark) were coated for 16 h at 4° C. with 2 μg/ml of either human recombinant IFI16 (SEQ ID No.:1) or control peptide solubilized in 0.2 ml of phosphate-buffered saline (PBS). After blocking with coating buffer containing 3% bovine serum albumin (BSA) in PBS, patients sera, diluted 1:100, were added in duplicate and incubated for 1 h at 37° C. After washing, HRP-conjugated rabbit anti-human IgG (dilution 1:4800) (DakoCytomation) was added and incubated for 1 h at 37° C. After substrate addition, absorbance was measured at 490 nm using a Bio-Rad microplate reader (Bio-Rad). The results were corrected by subtracting the background reactivity of the reference mixture.
[0041] Data Analysis and Statistical Calculations
[0042] Statistical analysis was performed by SPSS statistical software (SPSS Inc., Chicago, USA) using the one-way ANOVA with Bonferroni Multiple Comparisons tests. Either Fisher's exact test or chi-square test was used for measuring association. The independent effect of significant variables was assessed using forward conditional logistic regression. Positivity cut-off values were calculated as the 95 th percentiles in the control population. With substantial deviation from normality, data was natural log transformed before parametric analysis was performed.
Results
Example 1
Anti-IFI16 Autoantibody Levels by ELISA and Skin IFI16 Immunoreactivity were Elevated in SSc and SLE
[0043] As recently reported in the normal epidermis from healthy controls, IFI16 expression was restricted to the basal layer ( FIG. 1A ). Notably, as shown in the representative sections in FIG. 1 , IFI16 expression was greatly increased and found ubiquitously expressed in all layers of the epidermis in the lesional skin from both SSc ( FIG. 1B ) and SLE ( FIG. 1C ) patients. Furthermore, the dermal inflammatory infiltrate showed IFI16 positive staining, indicating that it is expressed to a high level in lymphocytes, fibroblasts and endothelial cells.
[0044] To verify whether the increased expression of IFI16 in the affected skin was related to the presence of anti-IFI16 autoantibodies, their presence and levels in serum samples from 100 SLE patients and 82 SSc patients were assessed using ELISA with recombinant IFI16 protein. Other autoimmune diseases, including SjS, RA and CU as well as healthy individuals as normal controls were also examined. In addition, to further assess the clinical specificity of anti-IFI16 autoantibodies, 40 sera from patients with chronic HCV infection were also subjected to anti-IFI16 ELISA. Absorbance values higher than the 95 th percentile of the control population (0.360) were considered to be positive in this study. As depicted in FIG. 2A , patients with SSc, SLE and SjS exhibited significantly (one-way ANOVA p<0.0001) higher anti-IFI16 antibody levels of the IgG isotype than normal controls did (SSc p<0.0005, SLE p<0.002 and SjS p<0.001 respectively). Anti-IFI16 titers above the 95 th percentile of the controls were observed in 21% of SSc, 26% of SLE and 50% of SjS respectively. By contrast, anti-IFI16 prevalence was 4% in RA, 5% in CU and 10% in HCV patients respectively. Thus, IgG autoantibody levels were increased in SLE, SjS and SSc but not in other autoimmune diseases, including RA and CU or in patients with increased polyclonal reactivity such as HCV-positive patients.
Example 2
Association of anti-IFI16 Antibodies with Clinical Parameters
[0045] Since the presence of anti-IFI16 autoantibodies had already been reported in both SjS and SLE, where a significant serological heterogeneity is well known to occur (14), but not in SSc, a decision was taken to gain more insight into the actual role of anti-IFI16 autoantibodies in SSc pathogenesis. Univariate analysis showed that anti-IFI16 autoreactivity in SSc patients was not associated with either disease duration or disease severity as measured by Medsger stage, HAQ disability index, organ involvement and positivity to other autoantibodies (data not shown). By contrast, a strict association between anti-IFI16 reactivity and the cutaneous form of the disease was found, with patients in the limited cutaneous scleroderma (lc-SSc) having higher anti-IFI16 IgG titers than patients with the diffuse form (dc-SSc) (p=0.017). Indeed, as shown in FIG. 2B , anti-IFI16 titers above the 95 th percentile of the controls were observed in 28% of patients with lc-SSc but only in 4% of dc-SSc (95% confidence interval for the difference 5-37%).
[0046] In line with previous reports, the presence or titers of anti-IFI16 antibodies did not correlate with clinical manifestations or disease activity in both SLE and SjS patients (data not shown).
Example 3
Logistic Regression Model and Sensitivity-Specificity Analysis for lc-SSc Prediction
[0047] In our samples the cutaneous form of SSc was significantly associated with both anti-centromere (χ 2 =18.771 p<0.0005) and anti-topoisomerase (χ 2 =32.689 p<0.0005) autoantibodies. Logistic regression showed that all the three serological markers were independent predictors of the cutaneous form of scleroderma, and their combination was able to explain 62% of the associated variability. This model was able to correctly predict 89% of the clinical presentation forms of scleroderma. Moreover, anti-IFI16 reactivity displayed lower sensitivity (28%) and higher specificity (96%) than those found with either anti-topoisomerase I (95% and 67% respectively) or anti-centromere (65% and 92% respectively). The combined use of anti-IFI16 and anti-centromere markers gave rise to the highest sensitivity and specificity score (79% and 92% respectively). Interestingly, in the SSc subgroup negative for both anti-centromere and anti-topoisomerase I reactivity, all patients with anti-IFI16 positivity displayed the limited cutaneous form of SSc (specificity 100% and positive predictive value 100%).
Example 4
Immunoblotting Analysis for anti-IFI16 Antibody
[0048] The presence of anti-IFI16 antibodies was also evaluated by immunoblotting analysis using recombinant IFI16 protein either full length or deleted fragments as schematically represented in FIG. 3A . Western blots were performed on 25 SSc sera, 17 from patients with anti-IFI16 titers above and 8 with titers below the 95 th percentile of the controls. As illustrated in the representative immunoblotting in FIG. 35 , low-titer sera did not exhibit reactivity with IFI16, thus confirming the specificity of the ELISA technique. By contrast, only 10 of the 17 IFI16 high-titer sera were positive, very likely because immunoblot detects antibodies directed against linear epitopes while ELISA either linear and conformational epitopes. Correlation between anti-IFI16 autoantibody titers and the intensity of immunoreactive bands was not depicted.
[0049] To further characterize the antigenic specificity of the IFI16 positive sera, the 10 sera recognizing linear epitopes were analyzed for their reactivity against the N-terminal (IFI16 N-term) and C-terminal (IFI16 C-term) fragments of IFI16 respectively. As shown in the representative immunoblot in FIG. 3C , 4 sera displayed reactivity against the N-terminal fragment, 3 against the C-terminal fragment, 2 recognized both fragments and 1 displayed no reaction.
[0050] All together these data suggest a polyclonal immune response against IFI16 in patients with SSc.
Example 5
Anti-IFI16 Autoantibodies in Patients Affected by Multiple Sclerosis
[0051] The presence of anti-IFI16 autoantibodies and their levels in serum samples from 163 patients affected by multiple sclerosis (MS) and 64 healthy individuals as normal controls were examined by ELISA with recombinant IFI16 protein. As shown in FIG. 4 , patients with MS exhibited significantly (unpaired t-test p<0.05) higher anti-IFI16 antibody levels of the IgG isotype than normal controls did.
[0052] Naturally, while the principle of the invention remains the same, the details of construction and the embodiments may widely vary with respect to what has been described and illustrated purely by way of example, without departing from the scope of the present invention as defined in the appended claims.
REFERENCES
[0000]
1. Landolfo S, Gariglio M, Gribaudo G, Lembo D. The Ifi 200 genes: an emerging family of IFN-inducible genes. Biochimie 1998; 80 (8-9):721-8.
2. Ludlow L E, Johnstone R W, Clarke C J. The HIN-200 family: more than interferon-inducible genes? Exp Cell Res 2005; 308(1):1-17.
3. Rozzo S J, Allard J D, Choubey D, Vyse T J, Izui S, Peltz G, et al. Evidence for an interferon-inducible gene, Ifi202, in the susceptibility to systemic lupus. Immunity 2001; 15(3):435-43.
4. Seelig H P, Ehrfeld H, Renz M. Interferon-gamma-inducible protein p16. A new target of antinuclear antibodies in patients with systemic lupus erythematosus. Arthritis Rheum 1994; 37(11):1672-83.
5. Uchida K, Akita Y, Matsuo K, Fujiwara S, Nakagawa A, Kazaoka Y, et al. Identification of specific autoantigens in Sjogren's syndrome by SEREX. Immunology 2005; 116(1):53-63.
6. Gariglio M, Azzimonti B, Pagano M, Palestro G, De Andrea M, Valente G, et al. Immunohistochemical expression analysis of the human interferon-inducible gene IFI16, a member of the HIN200 family, not restricted to hematopoietic cells. J Interferon Cytokine Res 2002; 22(7):815-21.
7. Calamia K T, Balabanova M. Vasculitis in systemic lupus erythematosis. Clin Dermatol 2004; 22(2):148-56.
8. Raffaella R, Gioia D, De Andrea M, Cappello P, Giovarelli M, Marconi P, et al. The interferon-inducible IFI16 gene inhibits tube morphogenesis and proliferation of primary, but not HPV16 E6/E7-immortalized human endothelial cells. Exp Cell Res 2004; 293(2):331-45.
9. LeRoy E C, Black C, Fleischmajer R, Jablonska S, Krieg T, Medsger T A, Jr., et al. Scleroderma (systemic sclerosis): classification, subsets and pathogenesis. J Rheumatol 1988; 15(2):202-5.
10. Valentini G, Medsger T A, Jr., Silman A J, Bombardieri S. Conclusion and identification of the core set of variables to be used in clinical investigations. Clin Exp Rheumatol 2003; 21(3 Suppl 29):S47-8.
11. Medsger T A, Jr., Silman A J, Steen V D, Black C M, Akesson A, Bacon P A, et al. A disease severity scale for systemic sclerosis: development and testing. J Rheumatol 1999; 26(10):2159-67.
12. Steen V D, Medsger T A, Jr. The value of the Health Assessment Questionnaire and special patient-generated scales to demonstrate change in systemic sclerosis patients over time. Arthritis Rheum 1997; 40(11):1984-91.
13. Gugliesi F, Mondini M, Ravera R, Robotti A, de Andrea M, Gribaudo G, et al. Up-regulation of the interferon-inducible IFI16 gene by oxidative stress triggers p53 transcriptional activity in endothelial cells. J Leukoc Biol 2005; 77(5):820-9.
14. Sherer Y, Gorstein A, Fritzler M J, Shoenfeld Y. Autoantibody explosion in systemic lupus erythematosus: more than 100 different antibodies found in SLE patients. Semin Arthritis Rheum 2004; 34(2):501-37. | Use of IFI16 protein, fragments or peptides thereof for differential diagnosis of the limited cutaneous form of scleroderma (Ic-SSc) in a subject suspected of or at risk of having an autoimmune disease and the corresponding method of diagnosis and kit. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to sensing devices and systems, and is particularly concerned with sensing devices and systems for use in monitoring the presence or activity of specific chemical analytes.
SUMMARY OF THE INVENTION
According to one aspect of the present invention a sensing device for use in monitoring the presence or activity of a specific chemical analyte, comprises an enclosure having a membrane-wall that is semi-permeable to said chemical analyte, macromolecular material contained within the enclosure, said material exhibiting physical change in response to contact with said chemical analyte, a sensor contained within the enclosure to respond to said physical change, and means for transmitting a signal from said sensing device dependent on the response of said sensor.
The sensing device according to the invention is especially applicable for monitoring the presence or level of activity of a specific bio-chemical, drug or other analyte in vivo, within the body of a human or animal patient. In this context the sensing device may be provided for implant subcutaneously or otherwise within the patient so that the particular analyte can be sensed as it permeates the semi-permeable wall of the device.
The said material may be such as to exhibit change in a Theological parameter thereof in response to the analyte. The parameter may be viscosity, and the material, which may be for example a mixture of concanavalin A and ficoll, may be responsive to the presence of glucose to exhibit a change of its viscosity or other parameter. In the context of response to glucose, the sensing device of the invention has particular application for in vivo monitoring of the blood-glucose of diabetic patients.
The means for transmitting a signal from the sensing device of the invention may be contained within said enclosure, and said enclosure may be in the form of a capsule wholly or substantially wholly of semi-permeable membrane. Moreover, the means for transmitting a signal from the sensing device may include means for deriving digital data in accordance with the response of the sensor and for transmitting this from said sensing device.
According to another aspect of the present invention a sensing system for use in monitoring the presence or activity of a specific chemical analyte, comprises a sensing device and interrogating means that is operable for interrogating said sensing device, said sensing device comprising an enclosure having a membrane-wall that is semi-permeable to said chemical analyte, macromolecular material contained within the enclosure, said, material exhibiting physical change in response to contact with said chemical analyte, a sensor contained within the enclosure to respond to said physical change, and means operable in response to interrogation of said sensing means by said interrogating means for transmitting a signal dependent on the response of said sensor, to said interrogating means.
The signal dependent on the response of said sensor may be transmitted to said interrogating means by electromagnetic-wave transmission. Similarly, interrogation of said sensing means may be effected by electromagnetic-wave transmission from said interrogating means. In this latter case, electrical power for the means operable in response to interrogation of said sensing means, may be derived from the electromagnetic-wave interrogating transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
A sensing system, and sensing devices for use therein, all according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a block schematic diagram illustrating the sensing system according to the present invention;
FIG. 2 is a sectional view of a sensing device according to the invention, that forms part of the system of FIG. 1;
FIG. 3 is a block-schematic representation of the electrical circuitry of the sensing device of FIG. 2;
FIG. 4 is a block-schematic representation of electrical circuitry that may be used as an alternative to the electrical circuitry of FIG. 3 for the sensing device of FIG. 2;
FIG. 5 provides a block-schematic representation of the electrical circuitry of a transponder of the sensing device of FIG. 2;
FIG. 6 provides a block-schematic representation of the electrical circuitry of an interrogator unit that forms part of the sensing system of FIG. 1;
FIG. 7 is illustrative of a practical implementation of the sensing system of FIG. 1; and
FIG. 8 is illustrative of a form of sensing device according to the invention that may be used as an alternative to that of FIG. 2 in the system of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The sensing system to be described is for use for in vivo monitoring of the presence or level of activity of a specific bio-chemical, drug or other analyte within a patient.
Referring to FIG. 1, the sensing system includes a sensing device 1 that is implanted subcutaneously in the patient. The sensing device 1 includes a non-toxic macromolecular mixture or compound 2 encapsulated within an envelope 3 of bio-compatible semi-permeable membrane. The mixture or compound 2 has the characteristic that its physical properties change when it is in the presence of the relevant analyte, and the change in the physical condition of the mixture or compound 2 that in this respect takes place when the analyte permeates the wall of the envelope 3 is sensed by a sensor 4 . The sensor 4 is encapsulated with the mixture or compound 2 within the envelope 3 , and supplies an electric signal dependent on the sensed physical-change to a measurement circuit 5 .
The circuit 5 , like the device 4 , is encapsulated with the mixture or compound 2 within the envelope 3 , and from the signal supplied by the sensor 4 derives a digital-data signal that provides a measure of the physical condition of the mixture or compound 2 sensed. This signal is supplied to a radio-frequency transponder 6 which is also encapsulated with the mixture or compound 2 within the envelope 3 .
The transponder 6 is interrogated externally of the implanted sensing device 1 by actuation of an interrogation unit 7 . The measurement data derived by the circuit 5 is in consequence transmitted from the transponder 6 and this data as received by the unit 7 is either processed and stored within the unit 7 locally, or communicated to a data-acquisition system (not shown). The activity of the chemical analyte within the patient can be determined from the measurement data received from the sensing device 1 and can thus be continually or periodically monitored by the system of the invention. Moreover, suitable alarm and/or other action (for example, administration of a drug) can be taken when the activity of the analyte makes this desirable or necessary in the context of the monitoring operation.
The sensing device of the invention has particular application in the monitoring of blood-glucose in diabetic patients. Attempts have been made to develop an in vivo glucose sensor for this purpose, focused on adapting known biosensor-technology. But these attempts have been largely frustrated by problems of bio-compatibility, drift, instability, fouling, infection and electrical interconnection with the implant. However, the principal problems arise from the inherent instability of any enzyme-based system which limits the potential life of the sensing device and the design of a reliable interface between the indwelling sensing device and its associated, external electronics. These problems can be to overcome to a major extent with the sensing system of the present invention in that the enclosure may be bio-compatible and contain a non-toxic macromolecular mixture or compound responsive by physical rather than bio-chemical change to the blood-glucose level of the patient. The physical response of the macromolecular mixture or compound is reversible so that the sensing device can have a very long operational life.
Although described.above as utilised as an implant, the sensing device may be used in other contexts where it is desirable or necessary to provide for monitoring the presence or activity of a specific chemical, using self-contained sensing without the necessity for external electrical or other connection with the sensing device.
The mixture or compound 2 has an important role in the sensing system and device of the invention in that it exhibits a physical change in response to the analyte that is being monitored. By way of example, the material 2 may be a mixture of concanavalin A and ficoll which exhibits a rheological change to glucose. Other suitable mixtures or compounds may be used, and for longevity and optimum performance may be custom synthesised using molecular-design or molecular-imprinting methods. The involvement of non-proteinaceous synthetic recognition molecules may be found preferable.
The physical change of the mixture or compound 2 sensed by the sensor 4 within the sensing device 1 may, as indicated above, be rheological, and may be specifically change of viscosity. By way of alternative, the physical change sensed may be related to electrical conductivity, density, volume, pressure or luminosity or fluorescence. Luminosity or fluorescence may be sensed by the sensor 4 during stimulation of the mixture or compound 2 by visible or non-visible light incident on the device 1 from an externally-located laser. A similar stimulation of a sensed physical property may be achieved using acoustic radiation.
The semi-permeable envelope 3 may be fabricated of metallic, semi-synthetic or natural materials, examples of which are sintered titanium, polyvinyl chloride, silicone rubber, nylon and cellulose derivatives. For in vivo applications of the sensing device 1 , the membrane is desirably treated with a chemical such as phosphoryl choline, or derivatives, to minimize cell or protein adhesion.
The sensing system of FIG. 1 may be used specifically for monitoring blood-glucose levels in a patient suffering from diabetes, and the sensing device of the system may then take the form shown in FIG. 2 .
Referring to FIG. 2, the sensing device in this case has the form of a thin capsule 11 containing for example a mixture of concanavalin A and ficoll, as the macromolecular material 12 . The mixture or compound 12 is encapsulated within a continuous, seamless wall 13 formed wholly or substantially wholly of semi-permeable membrane. A sensor 14 immersed in the mixture or compound 12 within the capsule 11 is connected through the wall of an environmental housing 15 that contains the electronic circuitry of the sensing device 11 . In particular, the housing 15 incorporates a substrate 16 to which the sensor 14 is coupled and which carries measurement and transponder circuitry 17 together with the transponder antenna 18 and a charge-storage capacitor 19 .
The capsule 11 is implanted subcutaneously in a patient to respond to change in his/her blood-glucose level. The change of viscosity that occurs in the mixture or compound 12 in response to the change in glucose level permeating the semi-permeable wall 13 , is sensed by the sensor 14 and communicated to the circuitry 17 . In particular, for a concanavalin A—ficoll mixture a large change in viscosity (for example, 1 to 10 mM) is exhibited between the minimum and maximum levels of a patient's blood-glucose level. The output of the sensor 14 in response to the change is translated within the circuitry 17 into data representative of the viscosity and, correspondingly, of the blood-glucose level, for transmission to the appropriate interrogation unit via the antenna 18 .
The sensor 14 in this example may be of a kind which in response to change of viscosity of the mixture or compound 12 , exhibits a change of piezo-mechanical coupling efficiency. This change can be used to create a voltage or phase change in an applied signal. In the case in which phase-change is utilised, the circuitry 17 may take the form illustrated in FIG. 3 .
Referring to FIG. 3, an oscillatory waveform is applied to the sensor 14 from an oscillator 20 , and the output signal of the sensor 14 is supplied via a voltage-buffer stage 21 to a phase detector 22 for comparison with the output of a voltage-controlled oscillator 23 in a phase-locked loop that includes a loop-filter 24 . The resultant output signal of the filter 24 is supplied with the output signal of the oscillator 20 to a signal processor 25 to derive the relevant data from the detected phase shift between the two signals, and to supply this to a transponder circuit 26 .
Electrical energy to power the electronics of the capsule 11 is derived within the transponder circuit 26 without the need for the capsule 11 to include a battery. The required power is derived from the interrogation signal transmitted from the interrogation unit 7 (FIG. 1 ). This signal received via the antenna 18 charges the storage capacitor 19 and it is from this charge that the circuitry 17 is powered to gather the blood-glucose measurement data and transmit it via the antenna 18 for external use.
In an alternative construction of the capsule 11 , the sensor 14 used is of a form that utilises the transmission of acoustic waves within the mixture or compound 12 . The form of sensor 14 and circuitry 17 used in this case is shown in FIG. 4 and will now be described.
Referring to FIG. 4, the sensor 14 in this case comprises spaced piezoelectric transducer elements 30 and 31 immersed in the mixture or compound 12 . The element 30 is energised from an oscillator 32 and the consequent vibrations transmitted via the mixture or compound 12 are detected by the element 31 . The resultant signal derived by the element 31 , which can be readily correlated in amplitude and frequency with viscosity of the mixture or compound 12 , is applied via a voltage buffer stage 33 for comparison with the output signal of the oscillator 32 , in a comparator 34 . The output signal of the comparator 34 is utilised within a processor 35 to derive in relation to the output signal of the oscillator 32 , the desired measurement data for indicating blood-glucose level. Data stored in a non-volatile memory 36 sets the datum value against which the measurement data is derived for transmission by a transponder circuit 37 .
The transponder 6 of FIG. 1 (or specifically the transponder units 26 and 37 of FIGS. 3 and 4 respectively) may be constructed as illustrated in FIG. 5 .
Referring to FIG. 5, the radio-frequency interrogation signal is received in the antenna 18 within a resonant circuit that is formed by an antenna coil 40 with shunt capacitor 41 . The oscillatory output across the coil 40 is supplied via a rectifier 42 to charge the storage capacitor 19 in providing electrical power to the electronics of the capsule 11 via a regulator 43 , and is also supplied via a comparator 44 to a demodulator 45 . The demodulator 45 derives data that is transmitted to the transponder 18 in the interrogation signal, and supplies this to a processor unit 46 . This data is used within the processor unit 46 for protocol synchronisation and to set and/or re-set datum levels for the measurement data signalled by the measurement circuit 5 from the sensor 4 (FIG. 1 ).
The data derived by the processor unit 46 is stored in a memory 47 . This stored data is read out and under control of the processor unit 46 is combined with other data in a MUX unit 48 for transmission via a modulator 49 and coil 50 of the antenna 18 . Transmission is controlled by the processor unit 46 in dependence upon power-supply operation as determined by a power on/reset unit 51 .
The interrogation unit 7 of the system of FIG. 1 may be as illustrated in FIG. 6 .
Referring to FIG. 6, the transmission of the interrogation signal to the sensing device 1 is effected via an antenna 60 that is supplied with the signal from a modulator 61 via a power-amplifier 62 . The modulator 61 modulates the transmitted radio-frequency signal with data that is derived from a control unit 63 that includes digital storage. This data is derived within the unit 63 or within a data-acquisition station (not shown) to which it may be connected, in dependence upon the data that is to be transmitted by the sensing device 1 and the datum levels to which measurement is to be carried out therein.
The data signals received by the antenna 60 from the sensing device 1 are amplified in an amplifier 64 and demodulated in a demodulator 65 for supply to the unit 63 . A comparator 66 is active to derive control input signals for the unit 63 dependent upon the transmitted and received signals.
The interrogation unit 7 of FIG. 1 may be implemented in the form of a unit that is worn on the wrist in the manner of a wristwatch. This is illustrated in FIG. 7 where a capsule 70 of the same form as capsule 11 of FIG. 2 is to be understood as having been implanted subcutaneously in the wrist of a patient, and the interrogation unit 71 in this case has straps 72 for holding it to the wrist immediately over the implanted capsule 70 .
Referring to FIG. 7, an antenna coil 73 is incorporated in the base of the unit 71 beneath the associated electronic circuitry 74 . The unit 71 also incorporates an LCD display 75 and an audible-alarm facility 76 together with push-buttons 77 for setting data.into the circuitry 74 and display 75 .
Although there is material advantage in providing the electronic circuitry for deriving the measurement data and its transmission and reception, within the same envelope as the mixture or compound and sensing device, this is not necessarily the case. In particular, as illustrated in FIG. 8, a sensing device comprises two capsules 80 and 81 , the capsule 80 having a semi-permeable wall 82 and containing the macromolecular mixture or compound 83 and immersed sensor 84 . The wall 85 of the capsule 81 on the other hand is non-permeable, and contains components 86 to 89 corresponding directly to the components 16 to 19 respectively of the integrated capsule 11 of FIG. 2 . Electrical connection between the sensor 84 and the circuitry 87 is effected by insulated conductors 90 . | An implanted sensing device ( 1 ) for monitoring an analyte (e.g. blood-glucose) includes a non-toxic macromolecular material ( 2 ) encapsulated within an envelope ( 3 ) of bio-compatible semi-permeable membrane. A sensor ( 4 ) responds to change of a physical property (e.g. viscosity) of the material ( 2 ) when the analyte contacts the material ( 2 ), to signal the change to a measurement circuit ( 5 ) that together with the sensor ( 4 ) and a transponder ( 6 ) are included within the envelope ( 3 ). The transponder ( 6 ) is interrogated externally of the implanted sensor ( 1 ) by an interrogation unit ( 7 ) to transmit measurement data for processing and storage. The interrogation signal is utilized within the device ( 1 ) to power the circuit ( 5 ) and transponder ( 6 ) and conveys data to the device for re-calibration or resetting of signal-datum values to compensate for aging or drift. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of, and claims priority to copending U.S. patent application Ser. No. 14/595,756, filed on Jan. 13, 2015, which was in turn a division of issued U.S. Pat. No. 8,999,831 issued on Apr. 7, 2015, both incorporated by reference in their entirety, and wherein such applications were made by, on behalf of, and/or in connection with the following parties to a joint research agreement: International Business Machines Corporation and GlobalFoundries. The agreement was in effect on and before the date the claimed invention was made, and the claimed invention was made as a result of activities undertaken within the scope of the agreement.
FIELD OF THE INVENTION
The invention disclosed broadly relates to the field of integrated circuit fabrication, and more particularly relates to improving the reliability of high-k transistors using a gate-last fabrication process.
BACKGROUND OF THE INVENTION
In the semiconductor industry, Moore's law states that the number of transistors on a chip doubles approximately every two years. These exponential performance gains present a challenge to the semiconductor manufacturing industry, along with the dual challenges of promoting power savings and providing cooling efficiency. The industry addresses these challenges in multiple ways. Selecting the gate dielectric and gate electrode are critical choices in enabling device scaling, and compatibility with CMOS technology. Two main approaches have emerged in high-k and metal gate (HKMG) integration: gate-first and gate-last. Gate-last is also called replacement metal gate (RMG) where the gate electrode is deposited after S/D junctions are formed and the high-k gate dielectric is deposited at the beginning of the process (high-k first).
A high-k first gate-last process is when the high-k dielectric is deposited first and the metal is deposited last (gate-last method). Gate-last is often referred to as the replacement gate option. “First” and “last”—gate denotes whether the metal gate electrode is deposited before or after the high temperature anneal process. Typically, the reliability of high-k gate stacks improve as a result of dopant activation anneal at a temperature of about 1000° C. However, this annealing process is only used for gate-first or high-k first, metal gate-last processes. The high-k last, metal gate-last process lacks such built-in high temperature treatment and thus reliability is a big challenge.
In the conventional process, if we want to apply a high thermal budget on high-k metals to improve reliability, the high-k metal layer needs to be formed prior to the dopant activation anneal (this is so-called gate-first process). The gate-first process typically requires robust encapsulation (using spacers) of the high-k metal gate stacks to prevent ambient oxygen to affect device characteristics. In addition, the high-k metal gate stack needs to be etched by RIE (reactive ion etching) at the time of gate patterning, which is typically challenging.
We provide a glossary of terms used throughout this disclosure:
GLOSSARY
k—dielectric constant value
high-k—having a ‘k’ value higher than 3.9 k, the dielectric constant of silicon dioxide
RTA—rapid thermal anneal.
A-Si—amorphous silicon
ALD—atomic layer deposition
CMOS—complementary metal-oxide semiconductor
FET—field effect transistor
FinFET—a fin-based, multigate FET
MOSFET—a metal-oxide semiconductor FET
PVD—physical vapor deposition
SiOx—silicon oxide
SiGe—silicon germanide
SiC—silicon carbide
RIE—reactive ion etching
ODL—optically dense layer; organically dielectric layer
STI—shallow trench isolation
S/D—source and drain terminals
NiSi—nickel silicide
C (DLC)—metal-free diamond-like carbon coating
SiN—silicon nitride
TDDB—time dependent dielectric breakdown
NBTI—negative bias temperature instability
PBTI—positive bias temperature instability
RTA—rapid thermal annealing
IL/HK—interfacial layer/high-k dielectric layer
TiN—titanium nitride
TiC—titanium carbide
TaN—tantalum nitride
TaC—tantalum carbide
TiAl—titanium aluminide
N2—nitrogen
Al—aluminide
W—tungsten
SUMMARY OF THE INVENTION
Briefly, according to an embodiment of the invention a method of fabricating a gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; annealing the structure at a high temperature of not less than 800° C.; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill. Optionally, a second annealing step can be performed after the first anneal. This second anneal is performed as a millisecond anneal using a flash lamp or a laser.
According to another embodiment of the present invention, a method of fabricating a gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over an area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; annealing the replacement gate structure at a high temperature of not less than 800° C.; removing both the thin metal layer and the sacrificial layer; performing a second rapid thermal anneal, this time at a temperature range between 400° C. and 800° C., inclusive; re-depositing a thin metal layer over the high-k dielectric layer; and depositing a metal layer for gap fill.
According to another embodiment of the present invention, a method of fabricating a gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over an area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; annealing the replacement gate structure at a high temperature of not less than 800° C.; performing a millisecond anneal; removing both the thin metal layer and the sacrificial layer; performing a second rapid thermal anneal, this time at a temperature range between 400° C. and 800° C., inclusive; re-depositing a thin metal layer over the high-k dielectric layer; and depositing a metal layer for gap fill.
According to another embodiment of the present invention, a method of fabricating a gate stack for a FinFET device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; annealing the structure at a high temperature of not less than 800° C.; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill. Optionally, a second annealing step can be performed after the first anneal. This second anneal is performed as a millisecond anneal using a flash lamp or a laser.
According to another embodiment of the present invention, a method of fabricating a gate stack for a FinFET device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over an area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; annealing the replacement gate structure at a high temperature of not less than 800° C.; performing a millisecond anneal; removing both the thin metal layer and the sacrificial layer; performing a second rapid thermal anneal, this time at a temperature range between 400° C. and 800° C., inclusive; re-depositing a thin metal layer over the high-k dielectric layer; and depositing a metal layer for gap fill.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
To describe the foregoing and other exemplary purposes, aspects, and advantages, we use the following detailed description of an exemplary embodiment of the invention with reference to the drawings, in which:
FIGS. 1A through 1D illustrate a replacement gate formation process, according to an embodiment of the present invention;
FIG. 1A is a simplified illustration of a gate structure after removal of a dummy gate, according to an embodiment of the present invention;
FIG. 1B is a simplified illustration of the gate structure of FIG. 1A after deposition of a gate metal layer and a sacrificial Si layer, followed by a RTA, according to an embodiment of the present invention;
FIG. 1C is a simplified illustration of the gate structure of FIG. 1B after removal of the sacrificial Si layer, according to an embodiment of the present invention;
FIG. 1D is a simplified illustration of the gate structure of FIG. 1C after deposition of a work function metal and gap fill metal, according to an embodiment of the present invention;
FIGS. 2A through 2F illustrate a replacement gate formation process, according to another embodiment of the present invention;
FIG. 2A is a simplified illustration of a gate structure after removal of a dummy gate, according to an embodiment of the present invention;
FIG. 2B is a simplified illustration of the gate structure of FIG. 2A after deposition of a gate metal layer and a sacrificial Si layer, following by a RTA, according to an embodiment of the present invention;
FIG. 2C is a simplified illustration of the gate structure of FIG. 2B after removal of the sacrificial Si layer, according to an embodiment of the present invention;
FIG. 2D is a simplified illustration of the gate structure of FIG. 2C , after removal of the thin metal layer, followed by an optional RTA, according to an embodiment of the present invention;
FIG. 2E is a simplified illustration of the gate structure of FIG. 2D , after deposition of the thin metal layer previously removed, according to an embodiment of the present invention;
FIG. 2F is a simplified illustration of the gate structure of FIG. 2E after deposition of work function and fill metals, according to an embodiment of the present invention;
FIG. 3 is a flowchart of the method of forming the replacement gate shown in FIGS. 1A through 1D , according to an embodiment of the present invention; and
FIG. 4 is a flowchart of the method of forming the replacement gate shown in FIGS. 2A through 2F , according to an embodiment of the present invention.
While the invention as claimed can be modified into alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the present invention.
DETAILED DESCRIPTION
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Thus, it will be appreciated that for simplicity and clarity of illustration, common and well-understood elements that are useful or necessary in a commercially feasible embodiment may not be depicted in order to facilitate a less obstructed view of these various embodiments.
We describe a gate-last, high-k metal gate with a novel improvement in reliability. We enable a high thermal budget treatment on high-k metal gate stacks while avoiding the aforementioned challenges of requiring etching at the time of gate patterning, and requiring a robust encapsulation of the high-k metal gate stack. We achieve our reliability improvement by adding a sacrificial layer and a high temperature anneal step to the high-k, gate-last formation process. The sacrificial layer is a silicon (Si) layer that we deposit after removing the dummy gate structure. By employing the sacrificial Si layer, followed by a high temperature anneal (800 to 1100° C.), we thus improve the device reliability. The sacrificial Si layer allows the temperature increase for the anneal process.
We further deviate from known methods in that our replacement gate process is performed without a silicide contact on the gate. Additionally, the high temperature anneal step in this process can be optionally used for the dopant activation traditionally used at the time of the source/drain junction formation. Then the annealing step usually performed at the source/drain junction formation can be skipped.
Referring now in specific detail to the drawings and to FIGS. 1A through 1D in particular, we show simplified illustrations depicting the replacement gate process, according to one embodiment of the present invention. This embodiment can be advantageously implemented in various CMOS devices, including FinFET devices. In this embodiment, we allow for one additional optional anneal. In FIG. 1A we show the gate structure 100 after removal of the dummy (sacrificial) gate. We grow an interfacial layer and deposit a high-k dielectric 110 .
In FIG. 1B , we deposit a gate metal layer 120 , followed by deposition of a sacrificial amorphous or poly-crystalline Si layer 130 . The gate metal layer 120 in this embodiment is a thin metal layer with a thickness of approximately 10 to 50 angstroms. It is preferably a thermally stable metal alloy, such as TiN, TiC, TaN, or TaC. The gate metal layer 120 can be deposited via atomic layer deposition (ALD) or physical vapor deposition (PVD). After deposition of the thin metal layer 120 , and the sacrificial Si layer 130 , we follow with a rapid (spike to 5 seconds) thermal anneal at high temperatures ranging from 800° C. to 1100° C. Spike is a type of RTA where temperatures ramp up and down quickly and the duration at the maximum temperature is almost zero. In one embodiment the annealing is performed in ambient nitrogen. After the RTA, we can follow with an optional millisecond anneal, using perhaps a laser anneal or a flash lamp anneal. This optional anneal is carried out for a very short amount of time. Without limiting the process window, we perform this anneal within a range of 1 to 100 milliseconds.
In FIG. 1C we remove the sacrificial Si layer 130 , leaving the thin metal layer 120 on the gate structure 100 . FIG. 1D we deposit a work function metal and gap fill metal 140 to finish the replacement gate 100 . The work function metal 140 can be a metal alloy, such as TiAl or TiN. It serves the purpose of setting the threshold voltage of the device to appropriate values. The gap fill metal 140 can be Al, or W.
The benefits and advantages in using this fabrication process for a gate-last high-k metal gate are:
1. High thermal budget in full replacement gate process. 2. Reliability (PBTI, NBTI, TDDB) improvement; 3. Simplified gate formation process (RIE, encapsulation), which enables closer proximity of stress elements to gate.
Referring now to FIGS. 2A through 2F , we present simplified diagrams of the replacement gate formation process, according to another embodiment of the present invention. This embodiment can also be advantageously implemented in various CMOS devices, including FinFETs. In this embodiment, we allow for two optional annealing processes. FIGS. 2A through 2C are the same steps as in the previous FIGS. 1A through 1C . In FIG. 2A we grow an interfacial layer and deposit a high-k dielectric 110 after removal of the dummy (sacrificial) gate. In FIG. 2B , we deposit a gate metal layer 120 , followed by deposition of a sacrificial amorphous or poly-crystalline Si layer 130 . The gate metal layer 120 in this embodiment, just as in the previous embodiment, is a thin metal layer with a thickness of approximately 10 to 50 angstroms. It is preferably a thermally stable metal alloy, such as TiN, TiC, TaN, or TaC. The gate metal layer 120 can be deposited via atomic layer deposition (ALD) or physical vapor deposition (PVD).
After deposition of the thin metal layer 120 and the sacrificial Si layer 130 , we follow with a rapid thermal anneal 140 at high temperatures ranging from 800° C. to 1100° C. After the RTA 140 , we can follow with an optional millisecond anneal 148 , using perhaps a laser anneal or a flash lamp anneal. In FIG. 2C we remove the sacrificial Si layer 130 , leaving the thin metal layer 120 .
In FIG. 2D we remove the thin metal layer 120 in a wet removal process, immediately followed by an optional second RTA 145 at 400° C.-800° C. for 30 seconds in N2 (ambient nitrogen). In FIG. 2E we re-deposit the thin metal layer 120 . In one embodiment where we do not perform the optional second RTA 145 , we do not need to remove and consequently re-deposit the thin metal layer 120 . Lastly, in FIG. 2F we deposit the work function and fill metals 150 . This last step correlates to FIG. 1D of the previous embodiment.
FinFET embodiment.
FinFET is commonly used to describe any fin-based, multigate transistor architecture regardless of number of gates. The same process as in the previous embodiment for a planar structure can be applied to a FinFET structure, except that high-k and metal films need to be deposited in a conformal manner to obtain desired device characteristics on the 3-D fin structure. This requirement limits the deposition for the high-k dielectric 110 , the gate metal layer 120 , and the work function metal 140 to conformal methods, such as atomic layer deposition (ALD).
We will now discuss the process steps for gate last high-k gate fabrication with respect to the flowcharts of FIGS. 3 and 4 . Optional steps are depicted in dotted boxes. It will be apparent to those with knowledge in the art that the fabrication of a gate stack on a semiconductor device involves more steps than are shown in FIGS. 3 and 4 . For example, we skip over the source/drain junction formation and show the process after the dummy gate has been removed. For clarity, we concentrate our explanation on those steps that deviate from the conventional fabrication of the high-k gate.
Referring now to FIG. 3 , we show a flowchart 300 of the process for fabricating a gate-last high-k metal gate 100 according to the embodiment of FIGS. 1A through 1D . In step 310 we grow an interfacial layer and deposit a high-k metal 110 after the dummy gate removal. In step 320 we deposit the gate metal layer 120 and the sacrificial Si layer 130 . This is followed by a RTA 140 of 800° C. to 1100° C. in step 330 .
Next, we can have a second, optional millisecond anneal 148 in step 340 . After the annealing process, we remove the sacrificial silicon layer 130 in step 350 . Lastly, we deposit a metal layer 150 consisting of a work function setting metal and a gap fill metal 150 of low resistivity. The benefits and advantages to this embodiment are:
1. Reliability improvement; and 2. Simplification of the gate formation process (RIE, encapsulation), which enables closer proximity of stress elements to gate.
Referring now to FIG. 4 , we show a flowchart 400 of the process for fabricating a gate-last high-k metal gate 200 according to the embodiment of FIGS. 2A through 2F . In step 410 we perform the RTA 140 after deposition of the gate metal 120 and Si layers 130 . Note that the reason for applying the sacrificial Si layer 130 is to allow the annealing at higher temperatures than would normally be advised. Once the high temperature annealing process is complete, the Si layer 130 can be removed. In optional step 420 we can perform a millisecond anneal 148 . We use very high temperatures ranging from 1100° C. to 1300° C. for the millisecond anneal.
In step 430 we remove the sacrificial Si layer 130 . Then we remove the gate metal (thin metal layer 120 ) in step 440 . In optional step 450 we can perform a second RTA 145 with temperatures between 400° C. and 800° C. Note that in this case we were able to perform a RTA 145 after removing the Si layer 130 because we did not use such high temperatures. Lastly, we finish the replacement gate in step 460 by depositing the work function and gap fill metals 150 for gap fill using low resistivity metals. The benefits and advantages to the embodiment of FIG. 4 are:
1. lower defect density owing to lift-off effect of Si residue 2. improved manufacturability 3. further recovery of oxygen vacancies in high-k layer by replacing the sacrificial thin metal layer which leads to improved gate leakage/reliability.
Benefits 1 and 2 are due to the removal of the thin metal layer 120 and benefit 3 is due to the combination of removal of the thin metal layer 120 and optional second RTA 145 .
Therefore, while there has been described what is presently considered to be the preferred embodiment, it will understood by those skilled in the art that other modifications can be made within the spirit of the invention. The above description(s) of embodiment(s) is not intended to be exhaustive or limiting in scope. The embodiment(s), as described, were chosen in order to explain the principles of the invention, show its practical application, and enable those with ordinary skill in the art to understand how to make and use the invention. It should be understood that the invention is not limited to the embodiment(s) described above, but rather should be interpreted within the full meaning and scope of the appended claims. | A method of fabricating a replacement gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; performing a first rapid thermal anneal; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to synchronizing the timing of data transfer with a system clock using a delay lock loop circuit. More particularly, the present invention relates to a method and apparatus for producing a symmetrical data clock by adding to or subtracting compensating delays to the falling edge of an internal clock.
BACKGROUND OF THE INVENTION
[0002] Modern high-speed integrated circuit devices, such as synchronous dynamic random access memories (SDRAM), microprocessors, etc., rely upon clock signals to control the flow of commands, data, addresses, etc., into, through, and out of the devices. Additionally, new types of circuit architectures such as SLDRAM require individual circuits to work in unison even though such circuits may individually operate at different speeds. As a result, the ability to synchronize the operation of a circuit through the generation of local clock signals has become increasingly more important. Conventionally, data transfer operations are initiated at the edges of the local clock signals (i.e., transitions from high to low or low to high).
[0003] In synchronous systems, integrated circuits are synchronized to a common reference system clock. This synchronization often cannot be achieved simply by distributing a single system clock to each of the integrated circuits for the following reason, among others. When an integrated circuit receives a system clock, the circuit often must condition the system clock before the circuit can use the clock. For example, the circuit may buffer the incoming system clock or may convert the incoming system clock from one voltage level to another. This processing introduces its own delay and/or skew, with the result that the locally processed system clock, often will no longer be adequately synchronized with the incoming system clock. In addition, the system clock itself may have a certain amount of skew within a tolerance set by system specifications. For example, an exemplary DDR SDRAM system may allow a system clock skewed to have a duty cycle of 55%/45%. The trend towards faster system clock speeds further aggravates this problem since faster clock speeds reduce the amount of delay, or clock skew, which can be tolerated.
[0004] To remedy this problem, an additional circuit is conventionally used to synchronize the locally processed clock to the system clock. Two common circuits which are used for this purpose are the phase-locked loop (PLL) and the delay-locked loop (DLL). In the phase-locked loop (PLL), a voltage-controlled oscillator produces the local clock. The phases of the local clock and the system clock are compared by a phase-frequency detector, with the resulting error signal used to drive the voltage-controlled oscillator via a loop filter. The feedback via the loop filter phase locks the local clock to the system clock.
[0005] In contrast, the delay-locked loop (DLL) generates a synchronized local clock by delaying the incoming system clock by an integer number of periods. More specifically, the buffers, voltage level converters, etc. of the integrated circuit device, for example the input buffers of an SDRAM memory device, introduce a certain amount of delay. The delay-locked loop (DLL) then introduces an additional amount of delay such that the resulting local clock is synchronous with the incoming system clock.
[0006] In certain synchronous circuit devices, for example double data rate (DDR) dynamic random access memory (DRAM), wherein operations are initiated on both the rising and the falling edges of the clock signals, it is known to employ a delay lock loop (DLL) to synchronize the output data with the system clock (XCLK) using a phase detector. In an exemplary case, the transition of the data signal is perfectly aligned with the rising or falling edge of the XCLK. The time from the rising or falling edge of the data clock to the time when the data is available on the output data bus (tAC) is within specifications. A phase detector is conventionally used to lock the rising edge of the output data signal from the DLL (DQ) to the rising edge of the XCLK. Since the rising edge of the DQ signal is phase-locked to the rising edge of the XCLK signal, the rising edge of data being output from the device is synchronized with the system clock XCLK.
[0007] FIG. 1 depicts a DDR DRAM data synchronizing circuit using a DLL as is presently contemplated in the art. A DQ data output signal from an array is input to output buffer 23 and has its timing adjusted to be synchronized with the XCLK signal 8 . At system initialization, a phase detector 2 is activated by an initialization signal 4 . The phase detector 2 compares the phase of the CLKIN signal 6 , a processed signal derived from the XCLK signal 8 , with the OUT_MDL signal 10 , a model of the data output signal DQ. The phase detector 2 then adjusts the DLL delay elements 12 using respective ShiftR 14 and ShiftL 16 signals, to respectively decrease or increase the time delay added to the CLKIN signal 6 with respect to the OUT_MDL signal 10 .
[0008] The Output Buffer Model 19 models the delays generated by the Output Buffer 23 and the CLK Buffer Model 21 models the delays generated by the Input Buffer 7 to produce an OUT_MDL signal 10 such that alignment of the OUT_MDL signal 10 with the CLKIN signal 6 will result in alignment of the XCLK signal 8 with the DQ data output signal 24 . By adjusting the delay of the CLKIN signal 6 through the DLL delay elements 12 , the phase detector 2 can align the rising edge of the DQ output signal 24 with the rising edge of the XCLK signal 8 .
[0009] The output data signal DQ 24 is provided to a data pad 31 and is synchronized with the system clock XCLK 8 .
[0010] In addition, the FIG. 1 circuit can also be used to adjust an output toggle clock signal DQS as shown in FIG. 9 . In this case, an additional output buffer 23 a is used to generate the DQS signal at pad 31 a . The DQS signal can be used for timing purposes, such as a data strobe signal. For purposes of simplifying the discussion below, the background discussion and the discussion of the invention will be described in the context of synchronizing the data output signal DQ with the system clock XCLK 8 , but the discussions herein apply to also synchronizing a DQS signal with the system clock XCLK.
[0011] FIG. 2 is a timing diagram for the synchronizing circuitry of FIG. 1 . As shown in FIG. 2 , the rising edge 26 of the XCLK signal 9 , which is carried on the XCLK signal line 8 of FIG. 1 , is aligned with the rising edge 28 of the DQ signal 25 , which is carried on the DQ signal line 24 of FIG. 1 . As is indicated by the arrows shown in FIG. 2 , the rising edge 30 of the DLLCLK signal 33 (carried on the DLLCLK signal line 32 of FIG. 1 ) initiates the rise and fall of the DLLR signal 21 (carried on the DLLR signal line 20 of FIG. 1 ), through the Rise Fall CLK Generator 18 ( FIG. 1 ), which in turn initiates the rising edge 28 of the DQ signal 25 . Likewise, the rising edge 34 of the DLLCLK* signal 37 (carried on the DLLCLK* signal line 36 ) initiates the rise and fall of the DLLF signal 23 (carried on the DLLF signal line 22 of FIG. 1 ) which in turn initiates the falling edge 42 of the DQ signal 25 . For proper data synchronization, the rising edges of the XCLK 9 and DQ 25 should be aligned within an allowed tolerance and the duty cycle of the data output timing signal DQ 25 should be within the specifications for the system in which the synchronizing circuitry will be used.
[0012] Unfortunately, however, not all synchronizing circuitry components are ideal or even exemplary. Non-symmetrical delays can be created by the input processing of the system clock including input buffering of the system clock signal using the buffer 7 . The system clock itself may exhibit an asymmetric duty cycle, for example, up to a 55/45 duty cycle for a typical SDRAM. Variations in layout, fabrication processes, operating temperatures and voltages, and the like, result in non-symmetrical delays among the DLL Delay Elements 12 . All of these non-symmetrical delays produce output timing signals of the DLL exhibiting a difference between the duration of a high (tPHL) and low (tPLH) portion of the DLL output signal. As shown in FIG. 6 , the high and low tPHL and tPLH signal portions, respectively, refer to the amount of time between transitions of the signal. If a signal remains high for a period longer than it stays low, then that signal is said to be asymmetric. On the other hand, if a signal is high and low for equal periods of time, then that signal is said to be symmetric.
[0013] Non-symmetrical delays also result in a skewed data eye and a larger difference 46 ( FIG. 2 ) between the falling edge 44 of the XCLK signal 9 and the falling edge 42 of the DQ signal 25 . In other words, as shown in FIG. 2 , for an XCLK signal 9 having a 55/45 duty cycle, due to inconsistencies in the DLL delay elements 12 ( FIG. 1 ), the DLLCLK 33 and DLLCLK* 37 signals may have a duty cycle of 40/60. Because it is the rising edge 30 of the DLLCLK signal 33 and the rising edge 34 of the DLLCLK* signal 37 from which the rising 28 and falling 42 edges, respectively, of the DQ signal 25 result, the non-symmetrical delays may result in a non-functional system. Furthermore, because the number of DLL Delay Elements used is cycle time dependent, the skew and difference 46 are also cycle time dependent. This unpredictable skew is undesirable for reliable high speed performance.
[0014] Therefore, there is a strong desire and need for synchronizing circuitry which compensates for the lack of symmetry in a signal synchronized by a delay-locked loop circuit with a system clock, thus enabling more reliable performance at high speeds.
SUMMARY OF THE INVENTION
[0015] The present invention provides a method and apparatus to compensate for skew and asymmetry of a locally processed system clock used to synchronize an output signal (e.g., a DQ data or DQS timing output signal) from a digital circuit, for example a memory device.
[0016] In its apparatus aspects the invention provides a first phase detector, an array of DLL delay elements and accompanying circuitry to phase-lock the rising edge of an output signal (e.g., DQ or DQS signal) with the rising edge of the system clock XCLK signal. Additionally, a comparator circuit, a register delay, an array of DLL delay elements and accompanying circuitry are provided to add or subtract delay from the falling edge of the output signal in order to produce a symmetrical output signal. The symmetrical output signal provides an improved timing margin for a given cycle time.
[0017] In its method aspects, the invention compares a processed system clock with a signal representative of an output signal (e.g., DQ or DQS signal) to adjust a setting of a delay circuit to phase-lock a rising edge of the output signal to a rising edge of an unprocessed system clock signal, producing a first delayed timing signal. A second delay circuit is adjusted according to asymmetries in a duty cycle of the first delayed timing signal, producing at least a second delayed timing signal. At least the first and second delayed timing signals are used to produce a substantially symmetrical output signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] These and other advantages and features of the invention will be more clearly understood from the following detailed description which is provided in connection with the accompanying drawings in which:
[0019] FIG. 1 illustrates a block diagram of a portion of a conventional circuit for generating a synchronizing data output signal;
[0020] FIG. 2 illustrates a timing diagram for selected signals of FIG. 1 ;
[0021] FIG. 3 illustrates a block diagram of a portion of a circuit for generating a synchronizing data output signal in accordance with the present invention;
[0022] FIG. 4 illustrates a diagram of a portion of the circuit of FIG. 3 ;
[0023] FIG. 5 illustrates a block diagram of another portion of the circuit of FIG. 3 ;
[0024] FIG. 6 illustrates a timing diagram for selected signals of FIG. 3 ;
[0025] FIG. 7 illustrates a processor system employing a method and apparatus of the present invention;
[0026] FIG. 8 illustrates a partial block diagram of a memory system constructed in accordance with an embodiment of the invention; and
[0027] FIG. 9 illustrates a variation of the FIG. 1 circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] For simplification, the invention will now be described with reference to synchronization of data output (DQ) from a memory device, it being understood that a memory device is not required, and that the invention applies to synchronizing the data output of any digital circuit which outputs data in a synchronized manner with reference to a system clock. In addition, the invention can also be used to produce a timing output signal DQS which is synchronized with a system clock.
[0029] FIG. 3 is a block diagram of an embodiment of a data synchronizing circuit according to the present invention. The embodiment in FIG. 3 includes a first phase detector 108 which, like phase detector 2 of FIG. 1 , detects the relative phase between the CLKIN signal 103 , a derivative of the system clock signal XCLK 102 , and the OUT_MDL signal 126 , which models the timing of the output buffer 134 which buffers and synchronizes the data output DQ signal 138 . In response to a phase difference between the CLKIN signal 103 and the OUT_MDL signal 126 , the first phase detector 108 adjusts the delay of DLL Delay Elements 106 to the CLKIN signal 103 by sending respective ShiftL 110 and ShiftR 112 signals to the DLL Delay Elements 106 to phase-lock the rising edges of the CLKIN 103 and OUT_MDL 126 signals. The Output Buffer Model 130 models the delays generated by the Output Buffer 134 and the CLK Buffer Model 128 models the delays generated by the Input Buffer 104 to produce an OUT_MDL signal 126 such that alignment of the OUT_MDL signal 126 with the CLKIN signal 103 will result in alignment of the XCLK signal 102 with the DQ signal 138 . Phase-locking the rising edges of the CLKIN 103 and OUT_MDL 126 signals respectively causes the rising edges of the XCLK 602 and DQ 624 signals ( FIG. 6 ) to align.
[0030] Once the first phase detector 108 has achieved a phase-lock, it outputs a phase-lock signal 124 to initiate operation of the comparator 148 . The comparator 148 compares the relative time durations of the high tPLH and low tPHL portions of the DLLCLK signal 118 and the DLLCLK* signal 122 , which is an inverted DLLCLK signal. In response to durational differences between tPLH and tPHL, the comparator 148 generates add and subtract signals 144 , 146 . The add and subtract signals 144 , 146 are used in the Rise Fall CLK Generator 132 to control the amount of delay added to or subtracted from the DLLCLK* signal 122 prior to generation of the DLLF signal 142 . The DLLR and DLLF signals 140 , 142 are generated in the Rise Fall CLK Generator 132 to correspond to the rising edge of the DLLCLK and (delayed) DLLCLK* signals 118 , 122 , respectively, and are used in the Output Buffer 134 to produce the output data timing signal 138 . As noted, the DLLR and DLLF signals 140 , 142 are also used in the Output Buffer Model and CLK Buffer Model blocks 130 , 128 to produce the OUT_MDL signal 126 . The output data signal DQ on line 138 has both its rising and falling edges synchronized with the system clock XCLK 102 .
[0031] FIG. 4 illustrates an exemplary embodiment of circuitry within the comparator 148 . A first converter circuit 211 is connected between a reference voltage Vref and ground and includes two serially connected enabling transistors 202 and 204 and a pull-down transistor 206 . Transistor 202 is connected to Vref while transistor 206 is connected to ground. When transistor 202 is on, a capacitor 214 is connected between the reference voltage Vref and ground as shown in FIG. 4 . The upper plate of the capacitor, connected to the reference voltage Vref, is also connected to a first input (+) of a comparison circuit 220 . The gates of the enabling transistors 202 and 204 are controlled by the phase lock signal 124 . The gate of the pull-down transistor 206 is controlled by the DLLCLK signal 118 .
[0032] A second converter circuit 213 which is similar to converter circuit 211 is provided for a second input (−) of comparison circuit 220 as shown in FIG. 4 . The second converter circuit 213 is of similar construction to that of converter 211 , except its pull-down transistor 212 is controlled by the DLLCLK* signal 122 . The upper plate of the capacitor 216 in the second converter circuit 213 is connected to a second input (−) of the comparison circuit 220 . Comparison circuit 220 compares the differences between the output of the converter circuits 211 , 213 for the DLLCLK and DLLCLK* signals 118 , 122 .
[0033] When the phase lock signal 124 is low, it will precharge capacitors 214 and 216 to Vref. When the phase lock signal 124 goes high to activate the gates of the enabling transistors 204 , 210 , the DLLCLK signal 118 controls the gate of the pull-down transistor 206 to selectively permit discharge of the capacitor 214 during the high time of the DLLCLK signal 118 . Also, the DLLCLK* signal 122 controls the gate of the pull-down transistor 212 to selectively permit the discharge of the capacitor 216 during the high time of the DLLCLK*. signal 122 . Because the DLLCLK* and DLLCLK signals 122 , 118 are inverted and non-inverted versions of the same clock signal, the comparison circuit 220 is able to generate an error signal 228 corresponding to the lack of symmetry in the output of the DLL delay elements 106 .
[0034] For example, if the ratio of high tPLH to the low tPHL portion of the DLL output is 60/40, then the comparison circuit 220 may generate an error signal 228 of appropriate polarity during the cycle which reflects the duration of the asymmetry, or 10% of the clock cycle in this example.
[0035] The error signal 228 is translated in the arbiter block 222 into two signals, the add signal 144 and the subtract signal 146 . The add and subtract signals 144 , 146 represent delay that may be added or subtracted, respectively, with respect to the timing of the falling edge of an output data signal 138 in order to achieve symmetry. The timing of the output data signal is determined in the Rise Fall CLK Generator 132 ( FIG. 3 ). An example of using the add and subtract signals 144 and 146 in the Rise Fall CLK Generator 132 is illustrated in FIG. 5 .
[0036] FIG. 5 shows an exemplary Rise Fall CLK Generator 132 . Each of the signals DLLR 140 and DLLF 142 are generated by passing the internal DLL clock signals DLLCLK and DLLCLK* 118 and 122 , respectively, through a Rise One-Shot Generator 302 , 304 , which generates a high pulse of short duration when it receives a transition from low to high. The DLLR and DLLF signals 140 , 142 are used to control the rising and falling of the output data signal 138 ( FIG. 3 ).
[0037] As shown in FIG. 5 , a Register Delay 306 is used in the DLLF data path upstream of the DLLF Rise One-Shot Generator 304 . The add and subtract signals 144 , 146 control the amount of delay added to or subtracted from the DLLCLK* signal 122 before the DLLF signal 142 is generated in the DLLF Rise One-Shot Generator 304 . In this way, the DLLF signal 142 , and hence the falling edge of the output data signal 138 , can be delayed an amount necessary to make the high tPHL and low tPLH portions of the DLL output signal substantially equal or within an allowed tolerance of each other. In other words, the output data signal 138 has a substantially symmetric duty cycle.
[0038] It should be readily understood that FIG. 5 illustrates merely one example of a Rise Fall CLK Generator 132 . Use of the Register Delay 306 in the DLLF data path is not required and it should be readily understood that a different delay circuit may be used in the DLLR data path with appropriate modifications to associated circuitry to achieve the same result. Alternatively, delay circuits may be used in both the DLLF and DLLR data paths with appropriate modifications to associated circuitry to achieve the same result. Also, the use of a Register Delay 306 is not required and other circuit elements may be used for timing synchronization as is well known in the art.
[0039] As demonstrated in the exemplary timing diagram of FIG. 6 , by adjusting the delay of the DLLF signal 622 , the output data DQ 624 can be generated with a 50/50 ratio (duty cycle). For example, in FIG. 6 the system clock XCLK 602 is shown with a 60/40 ratio of high tPLH to low tPHL signal portions. Due to delays added by the DLL Delay Elements 106 , the DLLCLK and DLLCLK* signals 604 , 606 have a 65/35 ratio.
[0040] As shown in the first timing sequence 650 , prior to phase lock or any compensation using the circuitry of the invention, the DLLCLK and DLLCLK*signals 604 , 606 may produce corresponding DLLR and DLLF signals 608 , 610 , having a duty cycle not substantially equal to 50/50 and not in phase with the system clock XCLK signal 602 .
[0041] The second timing sequence 670 is produced after the phase-locking is completed by phase detector 108 , but before the operation of the comparator 148 . This second sequence 670 shows signals DLLR and DLLF signals 616 , 618 generated in phase with the rising edge of the system clock XCLK 602 , but still having the asymmetric duty cycle of the system clock and further exacerbated by the DLL Delay Elements 106 .
[0042] Finally, the third timing sequence 690 is produced using the comparator 148 and accompanying adjustment of the timing of the DLLF signal 142 . The subtract signal 620 is generated in the arbiter block 222 of the comparator 148 ( FIG. 4 ) and used to adjust the Register Delay 306 in the Rise Fall CLK Generator 132 ( FIG. 5 ), thereby adjusting the timing of the DLLF signal 622 , as shown in FIG. 6 . The resulting output data signal 624 has an acceptable ratio of high tPLH to low tPHL signal portions and thus exhibits a substantially symmetric 50/50 duty cycle.
[0043] The symmetric quality of the output data signal 624 permits improvement of the timing budget by maximizing the data eye used for synchronization of data output.
[0044] Thus, in reference to FIGS. 3-6 , to produce a symmetric data output signal DQ 138 having a rising edge aligned with the rising edge of the XCLK 102 , a phase detector 108 , comparator 148 and Rise Fall CLK Generator 132 are used to separately initiate rising and falling edges of the DQ signal 138 . When a system clock signal XCLK 102 is received, it is processed and compared with a signal representative of the timing of a DQ signal 138 . The processed system clock signal CLKIN 103 is delayed by DLL Delay Elements 106 controlled by a phase detector 108 to produce a delayed system clock signal DLLCLK 118 . The inverse of the delayed system clock signal DLLCLK* 122 is then further delayed by a Register Delay 306 under the control of a comparator 148 . In this way, the rising edge of the system clock signal XCLK 102 may be aligned (phase locked) with the rising edge of the data output signal DQ 138 and the data output signal DQ 138 may be generated so that it is symmetric.
[0045] FIG. 7 illustrates a processor system which employs logic circuits and selection methodologies in accordance with the method and apparatus of the invention.
[0046] As shown in FIG. 7 , a processor based system, such as a computer system 700 , for example, generally comprises a central processing unit (CPU) 702 , for example, a microprocessor, that communicates with one or more input/output (I/O) devices 712 , 714 , 716 over a system bus 722 . The computer system 700 also includes random access memory (RAM) 718 , a read only memory (ROM) 720 and, in the case of a computer system may include peripheral devices such as a floppy disk drive 704 , a hard drive 706 , a display 708 and a compact disk (CD) ROM drive 710 which also communicate with the processor 702 over the bus 722 . The RAM 718 is preferably constructed with delay-lock loop (DLL) circuitry for synchronizing the data output of the memory devices with a system clock using the method and apparatus of the invention described above with reference to FIGS. 3-6 . It should be noted that FIG. 7 is merely representative of many different types of processor system architectures which may employ the invention.
[0047] As illustrated in FIG. 8 , in another embodiment of the invention, a memory system 900 is provided including at least one or a plurality of memory devices 933 constructed with delay-lock loop (DLL) circuitry which can be used to synchronize the data output of the memory devices 933 with a system clock using the method and apparatus of the invention described above with reference to FIGS. 3-6 . Within the memory system 900 , some or all of the plurality of memory devices 933 may be arranged on at least one memory module 935 . In a preferred configuration, the memory system 900 would include a plurality of memory modules 935 , each containing at least one or a plurality of memory devices 933 constructed with the synchronizing circuitry as described above with reference to FIGS. 3-6 .
[0048] While the invention has been described and illustrated with reference to specific exemplary embodiments, it should be understood that many modifications and substitutions can be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims. | An apparatus and method is disclosed to compensate for skew and asymmetry of a locally processed system clock used to synchronize an output signal, e.g., a data signal or a timing signal, from a logic circuit, for example a memory device. A first phase detector, array of delay lock loop (DLL) delay elements and accompanying circuitry are disclosed to phase-lock the rising edge of the output signal with the rising edge of the system clock XCLK signal. Additionally, a comparator circuit, a register delay, an array of DLL delay elements and accompanying circuitry are disclosed to add or subtract delay from the falling edge of the DQ signal in order to produce a symmetrical output of the DQ signal. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to search engines, and more particularly, to a search engine for a knowledge base that is capable of determining a match answer and an alternative answer based on a history record of cumulative probability values.
[0003] 2. Related Art
[0004] Conventional search engines are located on a server side of a client-server environment. As a result, application of these search engines relative to knowledge bases that are located client-side is very difficult. For example, a knowledge base loaded to a portable digital assistant is incapable of searching unless communicable with a server-side search engine. Even if the client-side is readily communicable with the server-side search engine, processing delays such as database or application server requests (from client to server) affect performance. Performance problems are generally related to the Javascript or Perl front-end loaded nature of conventional server side systems and their related back-end DB2 or Oracle servers.
[0005] Conventional search-engines also do not address locating exact information that a user requests since they apply very complex layers of software abstraction, e.g. the Berkley search engine strategy and artificial intelligence algorithms.
[0006] Other disadvantages of conventional search engines are their inability to learn from prior searches for a user relative to a given knowledge base. That is, they do not readily provide user preferences relative to a knowledge base.
[0007] In view of the foregoing, there is a need in the art for a search engine that is client-side, high performance and learns user preferences.
SUMMARY OF THE INVENTION
[0008] The invention provides a search system and method that may be implemented in a client-side environment, provides high performance and creates user preferences relative to a knowledge base. The search system may also be natural language based. In addition, it is applicable to a variety of knowledge bases and can be adapted to other applications such as on-line help, interactive training, wizard functions, virtual chat sessions, intelligent bots, etc.
[0009] In a first aspect, the invention provides a method for searching a knowledge base having a plurality of answer objects for a match answer and an alternative answer, comprising: inputting a search term; beginning a search at a random location in the knowledge base to identify the match answer; determining a match answer category from the match answer; determining a look-up association based on the match answer category and a search history; plugging the look-up association into an alternative answer probability table to identify an alternative answer category; and performing a secondary search at a second random location in the knowledge base to find the alternative answer that belongs to the alternative answer category.
[0010] In a second aspect, the invention provides a user preference search system for searching a knowledge base to find a match answer and an alternative answer for a search term, comprising: a search engine that performs a first search at a first location in the knowledge base and returns a match answer, and performs a second search at a second location in the knowledge base to find an alternative answer, wherein the alternative answer belongs to an alternative answer category determined by plugging a look-up association into an alternative answer probability table; and a table update system that updates the alternative answer probability table based on a table of previously determined category answer associations.
[0011] In a third aspect, the invention provides a program product stored on a recordable medium for searching a knowledge base for a match answer and an alternative answer, comprising: means for inputting a search term; means for beginning a search at a random location in the knowledge base to identify the match answer; means for selecting a match answer category from the match answer; means for determining a look-up association based on the match answer category and a search history; means for plugging the look-up association into an alternative answer probability table to identify an alternative answer category; and means for performing a secondary search at a second random location in the knowledge base to find the alternative answer that belongs to the alternative answer category.
[0012] The foregoing and other features of the invention will be apparent from the following more particular description of embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The embodiments of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein:
[0014] FIG. 1 shows a block diagram of a user preference search system in accordance with the present invention.
[0015] FIG. 2 shows organization of a knowledge base in accordance with the present invention.
[0016] FIG. 3 shows a history table in accordance with the present invention.
[0017] FIG. 4 shows an alternative answer probability table in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] With reference to the accompanying drawings, FIG. 1 depicts a block diagram of a user preference search system 10 that searches knowledge base 36 in response to a search input string, i.e., natural language (NL) command 12 and outputs a match answer 14 and an alternative answer 16 . Search system 10 may be implemented in any type of computer system that, for instance, includes memory, a processing unit, a computer program, input/output devices (I/O), etc. Knowledge base(s) 36 may be provided as part of search system 10 or separately. The features of search system 10 may be implemented as a program product that include: (1) a natural language (NL) parser 18 that receives the NL command 12 and generates one or more search terms 20 ; (2) a search engine 22 that receives a search term 20 and generates a match answer 14 based on a primary search 24 and an alternative answer 16 based a table look-up 28 and secondary search 25 ; and (3) a table update system 32 that maintains/updates a history table 34 and an alternative answer probability table 30 .
[0019] In the example described herein, search system 10 may be provided on a client-side of operations with knowledge base 36 loaded to system 10 . An association history table 34 of user preferences, specific to knowledge base 36 , is utilized to generate search results. However, it should be noted that search system 10 could be configured to operate with a plurality of knowledge bases, each having an associated history table 34 . The natural language format makes the system 10 user friendly, and could be readily adapted to other applications, such as on-line help, interactive training, wizard functions, virtual chat sessions, intelligent bots, etc.
[0000] Searching
[0020] Knowledge base 36 comprises a database of possible “answer objects” 40 , as shown in FIG. 2 . Each answer object 40 generally includes, e.g., a category, one or more target words 46 , a description, and a URL. Exemplary entries of knowledge base 36 are shown in FIG. 2 . When a search term 20 matches one of the target words 46 , a hit occurs, and an answer (e.g., the URL, category and description) can be returned to the user. Often, a target word 46 may appear in many different answer objects 40 , so there may be many potential answers to an inputted search term 20 . The present invention seeks to limit the number of answers generated by search engine 22 to two answers, a match answer 14 and an alternative answer 16 based on recorded user preferences.
[0021] To achieve this, search engine 22 includes a primary search 24 that initiates a search at a random location 42 in the knowledge base 36 . When a first answer object 40 containing the search term 20 is identified, a match answer 14 is outputted. Next, an alternative answer category 15 for alternative answer 16 is selected using category association system 26 and table look-up 28 . Once the alternative answer category 15 is selected, a secondary search 25 occurs beginning at a second random location 44 in the knowledge base 36 . The secondary search 25 searches for the search term 20 only in answer objects 40 that belong to the alternative answer category 15 . When a hit occurs, the alternative answer 16 is output. In the exemplary embodiments described herein, answer objects 40 belong to one of four categories labeled as Marketing, Products, Contacts, and Other. However, it should be recognized that any number of categories and/or labels could be used without departing from the scope of the invention.
[0022] Identifying an alternative answer category 15 after the match answer 14 is found is accomplished in a two-step process as follows. First, category association system 26 determines a look-up association 17 for the match answer 14 . For instance, if the match answer 14 belonged to “category 1 :Marketing,” then category association system 26 would determine the best association, such as “category 2 :Products” resulting in a “ 1 - 2 ” look-up association.
[0023] Once determined, table look-up 28 plugs the look-up association 17 into alternative answer probability table 30 to determine the alternative answer category 15 . FIG. 4 depicts an example of an alternative answer probability table 30 . As can be seen for the case of look-up association 1 - 2 , category 1 :Marketing has a 100% ( 1 / 1 ) probability of occurring, and therefore would be selected as the alternative answer category 15 . For the case of look-up association 2 - 4 , category 3 :Contacts has a 75% ( 3 / 4 ) probability of occurring and category 4 :Other has a 25% ( 1 / 4 ) chance of occurring. Therefore in this case, category 3 :Contacts would be selected as the alternative answer category 15 . The process of building alternative answer probability table 30 is described below.
[0024] As noted, in order to access alternative answer probability table 30 , a look-up association 17 must be inputted. A look-up association 17 can be determined in any manner. In one exemplary embodiment, look-up associations are determined from a history table 34 , such as that shown in FIG. 3 . As can be seen in the left most column, all category association possibilities are provided, e.g., 1 - 1 , 1 - 2 , . . . 4 - 3 , 4 - 4 . To determine the appropriate look-up association 17 for the category 13 of the match answer 14 , the sum of all entries for each association are examined, and the highest sum is used as the association. For instance, if the match answer 16 was in category 2 :Products, then the look-up association 17 would be 2 - 4 , since that association has the highest sum value, sum=4, of 2 - 1 , 2 - 2 , 2 - 3 and 2 - 4 . As will be described below, the history table 34 is maintained by table update system 32 , which is then used to generate alternative answer probability table 30 .
[0025] In summary, the first step is to begin a search at a random location in the knowledge base 36 to identify a match answer 14 . Once the match answer 14 is found, a look-up association 17 is determined from history table 34 based on the match answer category 13 . Next, the look-up association 17 is plugged into the alternative answer probability table 30 to identify an alternative answer category 15 . Once the alternative answer category 15 is identified, as secondary search 25 is performed beginning at a second random location 44 in the knowledge base 36 , which finds the next occurrence of the search term 20 belonging to the alternative answer category 15 .
[0000] Table Updating
[0026] Whenever a user inputs a search, preference information is extracted and stored in history table 34 , such as that shown in FIG. 3 . Specifically, a category association 27 comprising the match answer category 13 and the alternative answer category 15 (i.e., 1 - 1 , 1 - 2 , . . . , etc., shown along the y axis) is incremented for the match answer category 13 (shown x axis). Thus, for example, if the match answer 14 belonged to category 1 Marketing and the alternative answer 16 belonged to category 2 :Products, then the cell 1 - 2 under Marketing would be incremented. If the match answer 14 belonged to category 3 :Contacts and the alternative answer 16 belonged to category 1 :Marketing, then the cell 3 - 1 under Contacts would be incremented. Because the process is repeated for each search, history table 34 becomes more and more robust. The sums of each row can be maintained and updated as shown in FIG. 3 .
[0027] From the history table 34 , alternative answer probability table 30 can be formed by examining the cells in each row, and apportioning a probability to the cells. For example, as shown in the first row (i.e., 1 - 1 ) of FIG. 3 , the Marketing and Contacts category cells each have a value of 1. Accordingly, each of these two cells are apportioned a probability of 1 / 2 (i.e., 50%), as shown in FIG. 4 .
[0028] It is understood that the various devices, modules, mechanisms and systems described herein may be realized in hardware, software, or a combination of hardware and software, and may be compartmentalized other than as shown. They may be implemented by any type of computer system or other apparatus adapted for carrying out the methods described herein. A typical combination of hardware and software could be a general-purpose computer system with a computer program that, when loaded and executed, controls the computer system such that it carries out the methods described herein. Alternatively, a specific use computer, containing specialized hardware for carrying out one or more of the functional tasks of the invention could be utilized. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods and functions described herein, and which—when loaded in a computer system—is able to carry out these methods and functions. Computer program, software program, program, program product, or software, in the present context mean any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after the following: (a) conversion to another language, code or notation; and/or (b) reproduction in a different material form.
[0029] While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims. | A system and method for searching a knowledge base for a match answer and an alternative answer. The method includes the steps of: inputting a search term; beginning a search at a random location in the knowledge base to identify the match answer; determining a match answer category from the match answer; determining a look-up association based on the match answer category and a search history; plugging the look-up association into an alternative answer probability table to identify an alternative answer category; and performing a secondary search at a second random location in the knowledge base to find the alternative answer that belongs to the alternative answer category. | 8 |
FIELD OF INVENTION
This invention relates to a method and apparatus useful in textile carding apparatus and drafting machines for reducing periodic variations in sliver weight caused by imperfections in rotary members of the machine.
BACKGROUND ART
In textile machines, such as carding machines and drawframes, it is frequently observed that periodic defects in the unit sliver weight, i.e. the weight per unit length, are created within the machine and which can be related to imperfections in particular rotating members of the machine such as a roller being out-of-round. Various evenness tests and frequency spectrographs have been previously employed to detect such defects.
Typically, no attempt is made to correct such defects short of replacing the defective component. As one known exception to the practice of replacing the component, a computer controlled sliver weight corrective system has been employed in which the speed of the doffer of a carding machine is adjusted square wave fashion, up and down between two set speeds, once per revolution of the doffer. In this computer control system, the angular position of the doffer is sensed and a program stored profile is built up relating the doffer position to the sliver weight at the time of sensing. This stored profile in the computer then directs the doffer speed to go up or down between the mentioned two set speeds. This system has the disadvantage of being dependent on the square wave form of correction, the further disadvantage of having to respond to the high inertia of the doffer, the disadvantage of being limited to two corrective speeds, and the disadvantage of having to periodically reset the two speeds. Thus, it has been known to attempt to correct for periodic variations in sliver weight by sensing and storing angular positions of a single relatively heavy rotating member, i.e. the doffer, and regulating its speed between two fixed speeds only in accordance with the measured unit weight of the sliver. However, it has not been known or recognized that a more efficient control of sliver weight could be obtained by regulating the speed of the feed roll, sensing the angular positions of plural rotating members and developing a control signal capable of regulating the feed roll speed so that such speed may be any of numerous speeds uniquely suited to the needed sliver weight correction.
An object of the present invention is that of providing a sliver weight corrective system and method which depends on using a computer or programmable controller for regulating the feed roll rather than the doffer and in a manner permitting a relatively wide range of speed changes.
Other objects will become apparent as the description proceeds.
SUMMARY OF INVENTION
The present invention contemplates a sensing device at the output delivery of the machine which gives a signal related to the weight per unit length of the sliver being produced. Other sensing devices are placed on selected rotating members of the machine to sense the moment to moment angular displacement of such members. During the first minute or two of operation of the machine at high speed, a microcomputer, programmable controller or the like is used to relate the moment to moment weight of sliver at the machine output to the moment to moment angular position of each of the rotating members. The preferred method of doing this is to average the readings over a period of time from a number of revolutions of the rotating member into a memory array which is indexed by the angular position of the rotating member. At the end of this period, the information obtained is saved and calculations are made to develop a periodic pattern of speed variations in opposition to the observed output pattern and which is applied as a control signal to the input member of the machine, i.e. the feed roll.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram of a typical carding machine equipped with a sliver weight control system according to the invention.
FIG. 2 is a schematic diagram of a typical drafting machine drawframe equipped with a sliver weight control system according to the invention.
FIG. 3A is a plot of sliver weight evenness produced by a carding machine with an out-of-round doffer.
FIG. 3B is a frequency spectrograph of the data seen in FIG. 3A.
FIG. 3C is a plot of sliver weight at the output of the carding machine referred to in FIG. 3A related to the angular position of the out-of-round doffer averaged over about thirty-two revolutions of the doffer.
FIG. 4A is a plot of sliver weight evenness produced by the carding machine referred to in FIG. 3A after corrections have been applied utilizing the system of the invention as illustrated in FIG. 1.
FIG. 4B is a frequency spectrograph of the data seen in FIG. 4A.
FIG. 4C is a plot of sliver weight at the output of the carding machine referred to in FIG. 3A related to the angular position of the out-of-round doffer averaged over about thirty-two revolutions after corrections have been applied utilizing the system of the invention as illustrated in FIG. 1.
FIG. 5A is a plot of sliver weight evenness produced by the carding machine referred to in FIG. 3A illustrating the effect of the corrections being applied by the invention system of FIG. 1 approximately two minutes after the machine is put into high speed operation.
FIG. 5B is a frequency spectrograph of the data seen in FIG. 5A.
FIG. 6A duplicates the curve seen in FIG. 3C and represents the repeated pattern of sliver weight as related to the angular position of the doffer roll with an illustrative offset phase angle A used for correcting the pattern of sliver variation by adjusting the speed of the feed roll.
FIG. 6B is similar to FIG. 6A except that it represents the repeated pattern of sliver weight as related to the angular position of the main cylinder with an illustrative offset phase angle B used for correcting the pattern of sliver variation by adjusting the speed of the feed roll.
FIG. 6C shows the patterns for the doffer roll and the main cylinder plotted together to the same time scale. In this example the main cylinder is assumed to be rotating about five times faster than the doffer roll and the patterns are assumed to be offset by illustrative offset angles A and B.
FIG. 6D illustrates the patterns of FIG. 6C combined by applying scale factors to each pattern.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows the major rotating members of a typical carding machine CM. In this machine, sensing of the unit sliver weight is done by passing the sliver through a sensor S having a trumpet F mounted on a gage plate which provides an electrical signal proportional to the strain on the gage plate due to the resistance force of the sliver passing through the trumpet. The silver is drawn through the trumpet by calendar, or drafting rolls G. A unit sliver weight sensing device of a type suited to the invention is described in U.S. Pat. No. 4,823,597 the teaching of which is incorporated herein by reference.
The doffer E and the main cylinder D are fitted with devices AP to sense angular position. Devices commonly used for this purpose are optical encoders and gear wheels with proximity detectors. In FIG. 1, gear wheels and proximity sensors are intended to be shown as examples and are shown on the doffer E and the main cylinder D. The input rotating member is the feed roll B which is turned by a variable speed motor H to introduce the feed mat into the carding machine CM. A microcomputer A is used to input information from the sliver unit weight sensor S and the shaft encoders AP, process this information, and finally, output a variable D.C. voltage which is used to determine the speed of the variable speed motor H which drives the feed roll B. Rotating members C, D and E other than the feed roll B are typically driven at fixed rates of speed, once high speed production has been started. A warning signal W such as a blinking red light, buzzer or the like may be employed and wired in circuit to indicate an improper condition.
FIG. 2, by way of a second embodiment, shows a typical drafting unit DU of a textile drawframe. In this application, the gage plate and trumpet E senses the sliver weight associated with the unit sliver weight sensor S' as previously explained. Shaft encoders or proximity sensors AP are applied to one or more pairs of drafting rolls B, C and D, and a variable speed motor F is connected to one of the input rolls B. The microcomputer A' fitted with warning signal W' acts in much the same way as microcomputer A on the carding machine. In a typical drafting unit, the drafting rolls D are driven at a fixed speed which is higher than the fixed speed at which the drafting rolls C are driven. The input roll B is driven at a variable speed, but in no case exceeding the fixed speed of rolls C.
In FIG. 3A, the weight evenness of sliver produced by a carding machine with an out-of-round doffer is plotted. In this graph, time is plotted on the horizonal axis and sliver weight is plotted on the vertical axis. It is this wide sliver weight variation as illustrated in FIG. 3A which the present invention seeks to avoid.
FIG. 3B is a frequency spectrograph of the same data as shown in FIG. 3A. The high peak to the left of the 5 yard mark is the major feature of this graph. The regular up and down pattern in the evenness test and the high peak on the spectrograph are evidence of a problem with the doffer roll.
FIG. 3C shows the weight pattern at the output related to angular position of the doffer, averaged over about thirty-two revolutions. After running a minute or two at high speed, the information graphed in FIG. 3C is copied to another memory area in the microcomputer which controls the carding machine. At this time,, the average sliver weight for the array is subtracting out from the individual array locations so that each element in the array represents the average deviation from the nominal weight. The microcomputer then multiplies this information by a negative scale factor previously found to produce optimum results for the speed being run and shifts the angular position by a phase angle previously found to give optimum results for the particular speed being run to form a look-up table of corrections to be applied to the speed of the input member of the machine. From this point on, while the machine is run at high speed production, the moment to moment angular position of the doffer is used as an index into the look-up table of corrections in order to produce a pattern of feed roll speed commands which opposes the periodic pattern which would otherwise be generated at the output.
In an alternate method, the saved information from the rotating members remains unchanged except for subtracting out the average of the entire array and corrections are calculated while the machine is running at high speeds as follows:
1. At a particular moment, the angular position of one of the rotating members, e.g. the doffer, is added to a stored number which represents the optimum phase angle shift which in turn is based on the distance between the transfer point to the doffer and the sensing point at the trumpet.
2. If the resulting number is greater than the number of increments of the shaft encoder, then the number is corrected by subtracting the number of increments in one revolution of the encoder.
3 The resulting number is used as an index into the saved memory array for that particular rotating member.
4. The number fetched from the memory array is then multiplied by a scale factor assigned to that rotating shaft.
5. The resulting value is then subtracted from the nominal speed command number for the feed roll.
6 The speed command number is further modified by a similar process for a second rotating member, e.g. the main cylinder.
7. The final speed command number is converted to a D.C. voltage which is used to determine the speed of the feed roll drive motor.
This second method has the advantage of allowing for different gain factors and phase angles to be tried while the machine is operating at high speed. This allows the optimum settings for these values to be determined without taking the machine out of production. Due to averaging effects within the carding machine, it is usually necessary to adjust the gain factor somewhat higher than would otherwise be necessary to compensate for the averaging effect. This is particularly true for tandem cards in which there are two main cylinders, two lickerins, and two doffers, as well as a transfer section.
FIG. 4A show the results of an evenness test made after the corrections have been applied. The resulting pattern shows little trace of the up and down pattern seen in FIG. 3A.
The frequency spectrograph seen in FIG. 4B shows the peak at the three yard wavelength to be greatly reduced.
FIG. 4C shows the weight pattern related to the doffer position in FIG. 4C to have been greatly reduced.
FIG. 5A shows the effect of the corrections being applied two minutes after the machine has been put into high speed operation.
FIG. 5B is a spectrograph of the data seen in FIG. 5A.
It should be noted that it is possible to correct for repetitive patterns of more than one rotating member simply by doing the same operations for each rotating member and summing the individual corrections. FIGS. 6A and 6B illustrate corrections based on the doffer roll only whereas FIGS. 6C and 6D illustrate corrections based on combining the doffer roll and main cylinder data.
FIG. 6A represents the repeating pattern of sliver weight as related to the angular position of the doffer roll as previously referred to in FIG. 3C. In this example, when the angular position is zero degrees, the history of sliver weight for that position is about 6% below the average sliver weight. For the purpose of correcting this pattern by adjusting the speed of the feed roll, it is necessary to find by calculation or by trial and error, an offset phase angle "A" which is shown in FIG. 6A. Adding this offset A to the present angular position of the doffer roll accommodates for transit time of the material between the feed roll and the doffer, and between the doffer and the sensing device at the output of the card.
FIG. 6B is similar to FIG. 6A except that FIG. 6B relates the repeating pattern of sliver weight as related to the angular position of the main cylinder. An angular offset "B" is shown which forms a similar function to angle "A" for the doffer roll.
FIG. 6C shows the patterns for the doffer roll and the main cylinder plotted together to the same time scale. In this example, the main cylinder is rotating about five times faster than the doffer roll so that five complete main cylinder patterns take place in the same time that one pattern of the doffer roll is completed. The patterns have been offset by angles "A" and "B" respectively.
In FIG. 6D, the patterns in FIG. 6C have been combined by applying scale factors to each pattern (in this example, the scale factor is unity), and summing the two patterns. This results in a plot of the moment-to-moment corrections to the speed of the feed roll. Since the correction of the speed of the feed roll is in opposition to the repeated patterns, the vertical scale of this digram is inverted as compared with other figures.
In summary it can be seen that all of the objective's have been achieved and that there have been described a dramatically improved system and method for correcting for repetitive variations in unit sliver weight. Various details may be changed without departing from the scope of the invention, the foregoing description being for the purpose of illustration only. | A method and apparatus for a textile carding machine or drafting machine drawframe having an out-of-round or otherwise imperfect rotating member is based on detecting and analyzing the relative rotative positions of selected of the machines rotating members in relation to the moment to moment weight of the sliver output and developing therefrom a control signal for varying the speed of rotation of a rotative feeding member so as to vary the sliver weight to compensate for such imperfections. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of hand held tools. More specifically, the present invention relates to the field of hexagonal wrenches and related safety, comfort, and convenience accessories and tools.
BACKGROUND OF THE INVENTION
[0002] Hexagonal wrenches or tool drivers, also referred to as allen wrenches or L-wrenches, have a hexagonal L-shaped body, including a long leg member and a short leg member. The end of either leg member is able to be inserted into a head of a screw or tool designed to accept a hexagonal wrench. Once inserted, rotational pressure is applied to the hexagonal wrench in order to tighten or loosen the screw. The leg members of the hexagonal wrench are designed to be of different lengths in order to allow a user flexibility when using the wrench in different environments and situations. For example, in a narrow, confined environment, the long leg of the hexagonal wrench is inserted into the head of the screw and the user will apply rotational pressure to the short leg. Or, if the environment is not so confined, the user is able to insert the short leg of the hexagonal wrench into the head of the screw and apply rotational pressure to the long leg.
[0003] Hexagonal wrenches are manufactured and distributed in multiple English and metric sizes in order to facilitate their use with screw heads of multiple sizes. Such wrenches are usually sold in a set which includes wrenches of multiple sizes but are also distributed individually.
[0004] When using a hexagonal wrench, a user will insert an end of the hexagonal wrench into the head of a workpiece such as a screw, and will then exert rotational pressure on the opposite end of the wrench in order to tighten or loosen the screw. Because of the size and dimensions of the hexagonal wrench it is particularly difficult to exert a great amount of rotational pressure on the hexagonal wrench when the long leg of the hexagonal wrench is inserted into the head of the screw. Because the hexagonal wrench is typically turned with the user's fingers, the user is able to also experience scrapes and cuts from the use of hexagonal wrenches in this manner. Ingenuitive users have also used other tools, including vice grips, pliers and the like, to turn hexagonal wrenches. However, this method is disadvantageous because such tools are able to lose their hold on the hexagonal wrench when rotational pressure is applied or are able to even bend or otherwise disfigure the hexagonal wrench.
SUMMARY OF THE INVENTION
[0005] A circular, cylindrical-shaped tool handle holds multiple sizes of tools, one tool at a time. The tool handle includes one or more holding slots, each positioned on the outer surface into which tools are inserted and held. Each holding slot includes one or more contoured compartments in which tools rest when engaged with the tool handle. Each contoured compartment is of a size and dimension which corresponds to one or more tool sizes.
[0006] In use, a tool such as a hexagonal wrench is positioned in an appropriate holding slot with the short leg or mounting end of the hexagonal wrench resting in the contoured compartment within the appropriate holding slot and the long leg of the hexagonal wrench protruding through an aperture or receiving hole formed through the bottom of the holding slot and penetrating the tool handle. The long leg has a proximal end for driving an appropriate screw or tool such as one with a head including a hexagonal-shaped recess. A lock is then positioned over the contoured compartment to irremovably confine the short leg of the hexagonal wrench within the contoured compartment and the appropriate holding slot. The lock has a cavity for coupling the lock to the tool handle by inserting the tool handle through the cavity. In some embodiments, the lock is selectively positionable along the length of the tool handle. The lock is able to be positioned to hold a tool in any one of the contoured compartments within any one of the holding slots. A user's movement of the lock is enhanced by external ridges on the lock.
[0007] A tool container of the present invention is designed to hold tools and a tool handle. A retaining mechanism and a securing mechanism are used in conjunction to enable the tool container and tools to be displayed without being removable until both the retaining mechanism and securing mechanism are removed appropriately later on, particularly after purchase.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a perspective view of an embodiment of the present invention showing the relationship of both a hexagonal wrench and a lock to a tool handle.
[0009] FIG. 2 illustrates a top view of a tool handle according to an embodiment of the present invention.
[0010] FIG. 3 illustrates a hexagonal wrench locked into a tool handle according to an embodiment of the present invention.
[0011] FIG. 4 illustrates a wrench locked into a handle according to an embodiment of the present invention.
[0012] FIG. 5 illustrates the multiple sizes of hexagonal wrenches which are able to be inserted into a tool handle according to an embodiment of the present invention.
[0013] FIG. 6 illustrates an embodiment of the handle of the present invention with continuous holding slots.
[0014] FIG. 7 illustrates a perspective view of a tool handle according to an embodiment of the present invention with a hexagonal wrench inserted through an appropriate receiving hole and showing a slidable lock positioned relative to the lock positioning slots.
[0015] FIG. 8 illustrates a perspective view of the slidable lock including inner ridges for engaging the positioning slots of the handle.
[0016] FIG. 9 illustrates a front view of an embodiment of a tool container in a closed configuration in accordance with an embodiment of the present invention.
[0017] FIG. 10 illustrates a side perspective view of an embodiment of a tool container in an open configuration with a retaining mechanism in accordance with an embodiment of the present invention.
[0018] FIG. 11 illustrates a perspective view of an embodiment of a tool container in a closed configuration with a securing mechanism and a retaining mechanism in accordance with an embodiment of the present invention.
[0019] FIG. 12 illustrates a bottom view of an embodiment of a tool container in a closed configuration with a retaining mechanism in accordance with an embodiment of the present invention.
[0020] FIG. 13 illustrates a flowchart of a method of securing a group of one or more tools in a tool container in accordance with an embodiment of the present invention.
[0021] FIG. 14 illustrates a front view of an embodiment of a tool container in a closed configuration in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] A perspective view of the hexagonal wrench handle 1 with a circular shape of an embodiment of the present invention is illustrated in FIG. 1 . Multiple sizes of hexagonal wrenches 3 are able to be inserted into and held by the handle 1 in an appropriate sized holding slot 4 . When inserted into the handle 1 , a hexagonal wrench 3 is positioned in the appropriately sized holding slot 4 with the short leg or mounting end of the hexagonal wrench 3 resting in the holding slot 4 and the long leg of the hexagonal wrench extending through an aperture formed through a bottom of the holding slot 4 and penetrating the handle 1 . The hexagonal wrench 3 includes an elongated rod having a bend through a predetermined angle. A proximal end of the hexagonal wrench 3 is for engaging a tool or screw which is driven by the hexagonal wrench 3 . The short leg member or mounting end of the hexagonal wrench 3 extends from the bend to a distal end.
[0023] Once a hexagonal wrench 3 is inserted into the handle 1 and rests in an appropriately sized holding slot 4 , a lock 2 is slid along the handle 1 and positioned over the holding slot 4 and the short leg of the hexagonal wrench 3 , thereby locking the hexagonal wrench 3 within the holding slot 4 . In some embodiments, the lock 2 contains a cam 12 , a bump or another appropriate implementation on the inside of the lock 2 for securing the lock 2 in place. When a cam is used, rotating action by the user, roughly a quarter turn, wedges the cam against the handle 1 and the wrench 3 .
[0024] FIG. 2 illustrates a top view of the handle 1 . When the wrench 3 ( FIG. 1 ) is positioned within the appropriate sized holding slot 4 , the long leg of the hexagonal wrench 3 extends through a corresponding receiving hole 5 in the handle 1 . The holding slot 4 and the receiving hole 5 are of a size to accept the corresponding hexagonal wrench 3 and hold it firmly so that it will not rotate or twist in the holding slot 4 during use. The receiving hole 5 extends through the full width of the handle 1 . In order to maximize the flexibility of the handle 1 of the embodiment illustrated in FIG. 2 , a receiving hole for a first sized hexagonal wrench is able to extend through a holding slot for a second sized hexagonal wrench on a diametrically opposing side of the handle 1 . For example, the receiving hole 6 extends from a holding slot positioned on the bottom of the handle 1 , with the top of the handle illustrated in FIG. 2 . Because the receiving hole 6 extends through the full width of the handle 1 , it has an opening in the holding slot 4 . When a hexagonal wrench is held by the handle 1 and positioned in the holding slot on the bottom of the handle 1 , the long leg of the hexagonal wrench will extend through the receiving hole 6 and also through the holding slot 4 .
[0025] The handle 1 has a circular, cylindrical shape having two ends and a circular, cylindrical surface.
[0026] FIGS. 3 and 4 illustrate a hexagonal wrench 3 locked within a holding slot 4 of the handle 1 by the lock 2 . The holding slots 4 of the handle are designed to be of a depth which will leave the top of the short leg of the wrench 3 flush with the top of the handle 1 so that when the lock 2 is positioned over the wrench 3 it will tightly hold the short leg of the wrench 3 within the holding slot 4 and will not allow it to rotate or twist during use. In some embodiments, the bottom of the lock 2 is designed with a separation 11 which allows the long leg of the wrench 3 to protrude through it.
[0027] FIG. 5 illustrates the multiple sizes of hexagonal wrenches which are able to be used with the handle 1 of an embodiment of the present invention. As stated above, each holding slot 4 is of a size which corresponds to a size of a conventional hexagonal wrench. In order to enhance the user's ability to exert rotational pressure on the larger hexagonal wrenches, the holding slots 4 which hold the larger wrenches 3 are oriented at the ends of the handle 1 of this embodiment. The holding slots 4 corresponding to smaller wrenches 3 are oriented in the middle of the handle 1 and when in use form a “T”-shaped handle. The drawing of FIG. 5 is for illustration purposes only, when in use the handle 1 of the present invention is designed to work with one hexagonal wrench at a time.
[0028] The handle 1 of an embodiment of the present invention illustrated in FIG. 5 is designed to hold hexagonal wrenches of English sizes including a 9/32 inch hexagonal wrench 60 , a ¼ inch hexagonal wrench 61 , a 7/32 inch hexagonal wrench 62 , a 3/16 inch hexagonal wrench 63 , a 5/32 inch hexagonal wrench 64 , a 9/64 inch hexagonal wrench 65 , a ⅛ inch hexagonal wrench 66 , a 7/64 inch hexagonal wrench 67 , a 3/32 inch hexagonal wrench 68 , a 5/64 inch hexagonal wrench 69 and/or other sized hexagonal wrenches. In an alternate configuration of an embodiment of the handle 1 of the present invention, designed to hold hexagonal wrenches of metric sizes, the wrench 60 would be a 10 mm hexagonal wrench, the wrench 61 would be an 8 mm hexagonal wrench, the wrench 62 would be a 6 mm hexagonal wrench, the wrench 63 would be a 5 mm hexagonal wrench, the wrench 64 would be a 4.5 mm hexagonal wrench, the wrench 65 would be a 4 mm hexagonal wrench, the wrench 66 would be a 3.5 mm hexagonal wrench, the wrench 67 would be a 3 mm hexagonal wrench, the wrench 68 would be a 2.5 mm hexagonal wrench and the wrench 69 would be a 2 mm hexagonal wrench. In some embodiments, the size of the wrench 3 which corresponds to the holding slot 4 is molded into, printed on, or engraved into the handle 1 to aid the user in efficiently finding the appropriate holding slot 4 for the necessary wrench 3 .
[0029] The lock 2 of an embodiment of the present invention is able to be positioned over any of the holding slots 4 for holding any of the hexagonal wrenches in place during use. The top of the lock 2 is rotated around the handle so that it is directly over the appropriate holding slot 4 and the separation 11 is positioned to allow the long leg member of the hexagonal wrench to extend therethrough.
[0030] The handle 1 is approximately 4.5 inches in length. The handle 1 is designed to provide a comfortable, user-friendly interface to a user's hand, in order to enhance a user's ability to exert rotational pressure on the hexagonal wrench 3 without subjecting the user to personal injury or requiring the use of additional tools.
[0031] The handle 1 is able to be composed of any appropriate material, which is of maximum strength and includes properties which resist materials that the handle will likely be exposed to, e.g., oil, grease, gasoline and the like. In some embodiments, the handle 1 is materially composed of polypropylene or other semi-crystalline polymer combination. Alternatively, the handle 1 is able to be materially composed of any suitable composition including, but not limited to aluminum or steel.
[0032] In some embodiments, the handle 1 of an embodiment of the present invention is constructed using an injection molded, core/cavity process as is well known in the art. Alternatively, the handle 1 is able to be constructed in any known manner.
[0033] The lock 2 is materially composed of a polypropylene-based material or other semi-crystalline polymer combination-based material in some embodiments but is able to also be composed of any appropriate material.
[0034] An embodiment of a handle 100 according to the present invention is illustrated in FIG. 6 . In this embodiment, the holding slots 4 are continuous along the surface of the handle 100 . Not all hexagonal wrenches are uniform in size and dimensions. The hexagonal wrenches manufactured by one manufacturer are able to have different dimensions than hexagonal wrenches manufactured by another manufacturer. Specifically, the lengths of the short legs of hexagonal wrenches are able to be different depending on the manufacturer. The continuous holding slots 4 of an embodiment of the present invention allow for use with hexagonal wrenches having different length short legs. When using a hexagonal wrench with a longer short leg the continuous holding slot 4 will receive and hold the extra length of the short leg. In this manner, hexagonal wrenches of different dimensions from multiple manufacturers are able to be accommodated by the handle 100 with continuous holding slots 4 .
[0035] Also, in the handle 100 of an embodiment of the present invention, the continuous holding slots are positioned on the circularly, cylindrically shaped handle 100 and the corresponding receiving holes 5 are positioned diametrically opposed, without a continuous holding slot 4 . It should be apparent to those skilled in the art that the continuous holding slots 4 within the handle 100 of an embodiment of the present invention is able to be positioned on any surface of the handle 100 .
[0036] The placement of a hexagonal wrench 3 into a continuous holding slot 4 is illustrated in FIG. 7 . The long leg of the hexagonal wrench 3 is inserted, as described above, into the appropriately sized receiving hole until the short leg of the hexagonal wrench 3 is seated in the continuous holding slot 4 . To engage the slidable lock 2 on the handle 100 , the top of the slidable lock is aligned with the surface of the handle 100 which includes the continuous holding slot 4 to be covered.
[0037] FIG. 8 illustrates a perspective view of the slidable lock 200 in an alternative embodiment. The slidable lock 200 is constructed so that the bottom of the lock 200 is smaller than the top of the lock in order to give the lock 200 a natural spring-like property which locks it to the handle 1 . The slidable lock 200 also includes a gap at the bottom.
[0038] The lock 200 is designed of a shape to closely correspond to the shape of the handle 1 . In some embodiments, the bottom of the lock 200 is designed to be slightly smaller than the top of the lock 200 in order to provide a built-in, self-clamping mechanism allowing the lock 200 to tightly bind itself to the outer surface of the handle 1 . The lock 200 is also designed with the external ridges 10 . The external ridges 10 are used by the user to unlock the lock 200 from the handle 1 and move the lock 200 along the handle 1 . In order to move the lock 200 along the handle 1 , the user pinches the lock 200 at the external ridges 10 which forces the bottom of the lock 200 apart and allows the lock 200 to be slid along the handle 1 . When pressure is applied to the lock 200 it will slide along the handle when the external ridges 10 are not pinched. However, pinching the external ridges 10 enhances the movement of the lock 200 along the handle. The lock 200 is able to be rotated around the handle 1 in order to be positioned over a holding slot 4 of the handle 1 .
[0039] FIG. 9 illustrates a front view of an embodiment of a tool container 350 in a closed configuration. The tool container 350 includes a tool container body 352 with receiving slots/grooves for receiving each of the hexagonal tools 3 . In some embodiments, there are other means for receiving each of the hexagonal tools 3 . In some embodiments, only one end of each of the hexagonal tools 3 extends beyond the tool container body 352 , and in some embodiments, both ends of each of the hexagonal tools 3 extend beyond the tool container body 352 . The tool container 350 also includes a hanging member 354 for hanging the tool container 350 on an object such as a display rod or hook in a store. In some embodiments, another mechanism for hanging the tool container 350 is implemented. In some embodiments, the tool container 350 also includes a location or cavity for receiving the tool handle 100 . In some embodiments, the tool container 350 includes a location for receiving any tool handle. In some embodiments, the tool container 350 includes raised features 380 for each of the hexagonal tools 3 which allow the user to determine the correct size hexagonal wrench required before removing the tool from the tool container 350 . The user is able to place a fastener over each of the raised features 380 until the correct size tool is determined for that fastener. In some embodiments, labeling of each of the tools is also included on the tool container 350 . The labeling is molded onto the tool container 350 or another implementation.
[0040] FIG. 10 illustrates a side perspective view of an embodiment of a tool container 350 in an open configuration with a retaining mechanism. The tool container 350 includes a tool container body 352 which further includes a first holding wing 360 and a second holding wing 362 . In some embodiments, a hinge or other mechanism allows the tool container 350 to open. In some embodiments, the first holding wing 360 and the second holding wing 362 open outwardly from each other. The first holding wing 360 contains receiving slots/grooves for receiving a first set of hexagonal tools 370 , and the second holding wing 362 contains receiving slots/grooves for receiving a second set of hexagonal tools 372 . In some embodiments, the first set of hexagonal tools 370 are standard and the second set of hexagonal tools are metric or vice versa. In some embodiments, there is only one set of tools. In some embodiments, there are other means for receiving each of the hexagonal tools. In some embodiments, the tool container 350 includes a location for receiving the tool handle 100 . In some embodiments, the tool container 350 includes a location for receiving any tool handle. In some embodiments, the tool container 350 also includes a hanging member 354 for hanging the tool container 350 on an object such as a display rod or hook in a store. In some embodiments, another mechanism for hanging the tool container 350 is implemented.
[0041] In some embodiments, the hanging member 354 includes a first member 354 ′ and a second member 354 ″ which open in opposite directions when the tool container 350 is opened. In some embodiments, the first and second members 354 ′ and 354 ″ are configured as a partial extension from the tool container body 352 , specifically, the first member 354 ′ is configured as a partial extension from the first holding wing 360 , and the second member 354 ″ is configured as a partial extension from the second holding wing 362 . In some embodiments, the first and second members 354 ′ and 354 ″ are each configured as a loop so that there is an aperture within the loop. In other embodiments, the first and second members 354 ′ and 354 ″ are configured in another fashion.
[0042] A retaining mechanism 358 is inserted within the tool container 350 , specifically, between the first holding wing 360 and the second holding wing 362 and extends beyond the hexagonal tools to prevent the tools from being removed from the tool container 350 . In some embodiments, the retaining mechanism 358 at least partially extends around the hexagonal tools. After the tool container 350 is opened, the retaining mechanism 358 is able to be removed, and subsequently, the hexagonal tools are able to be removed. In some embodiments, the retaining mechanism 358 is plastic. In some embodiments, the retaining mechanism is metal. In some embodiments, the retaining mechanism comprises a different material.
[0043] FIG. 11 illustrates a perspective view of an embodiment of a tool container 350 in a closed configuration with a securing mechanism and a retaining mechanism. The tool container 350 includes a tool container body 352 with a first holding wing 360 and a second holding wing 362 ( FIG. 12 ). The first holding wing 360 contains receiving slots/grooves for receiving a first set of hexagonal tools 370 , and the second holding wing 362 ( FIG. 12 ) contains receiving slots/grooves for receiving a second set of hexagonal tools 372 ( FIG. 12 ). The tool container 350 also includes a hanging member 354 for hanging the tool container 350 on an object such as a display rod or hook in a store. In some embodiments, another mechanism for hanging the tool container 350 is implemented.
[0044] A retaining mechanism 358 is stored within the tool container 350 , specifically between the first holding wing 360 and the second holding wing 362 ( FIG. 12 ) and extends beyond the hexagonal tools to prevent the tools from being removed. In some embodiments, the retaining mechanism 358 at least partially extends around the hexagonal tools. After the tool container 350 is opened, the retaining mechanism 358 is able to be removed, and subsequently, the hexagonal tools are able to be removed.
[0045] In some embodiments, a securing mechanism 356 is implemented so that the tool container 350 is not able to be opened until the securing mechanism 356 is removed. The securing mechanism 356 is able to be any device that prevents the tool container 350 from being opened until the tool container 350 should be permitted to be opened. Examples of securing mechanisms include, but are not limited to, zip ties, locks and magnetic locks. While the securing mechanism 356 is in place, the retaining mechanism 358 is not able to be removed, thus the tools are not able to be removed. In some embodiments, the tool container 350 is secured closed in another fashion, such as by gluing, sealing the hanging member together or other ways.
[0046] FIG. 12 illustrates a bottom view of an embodiment of a tool container 350 in a closed configuration with a retaining mechanism. The container body 352 includes a first holding wing 360 and a second holding wing 362 . The first holding wing 360 holds a first set of hexagonal tools 370 , and the second holding wing 362 holds a second set of hexagonal tools 372 . A retaining mechanism 358 is stored within the tool container 350 , specifically between the first holding wing 360 and the second holding wing 362 and extends beyond the hexagonal tools to prevent the tools from being removed. In some embodiments, the retaining mechanism 358 at least partially extends around the hexagonal tools. After the tool container 350 is opened, the retaining mechanism 358 is able to be removed, and subsequently, the hexagonal tools are able to be removed.
[0047] FIG. 13 illustrates a method of securing a group of one or more tools in a tool container 350 . In the step 400 , the group of tools is inserted into the tool container 350 . In some embodiments, a set of metric tools are inserted into a first holding wing of the tool container 350 and a set of standard tools are inserted into a second holding wing of the tool container 350 . In some embodiments, a tool handle 100 is also inserted into the tool container 350 . In the step 402 , a retaining mechanism 358 is inserted into the tool container 350 . The retaining mechanism 358 is inserted between holding wings and is configured so that the tools are not removable while the retaining mechanism is in place. In the step 404 , the tool container 350 is secured in a closed position with a securing mechanism 356 . With the tool container 350 secured in a closed position, the retaining mechanism is not removable, thus making the tools not removable.
[0048] FIG. 14 illustrates a front view of an embodiment of a tool container 500 in a closed configuration. The tool container 500 includes a tool container body 552 with receiving slots/grooves for receiving each of the hexagonal tools 3 . In some embodiments, there are other means for receiving each of the hexagonal tools 3 . In some embodiments, only one end of each of the hexagonal tools 3 extends beyond the tool container body 502 , and in some embodiments, both ends of each of the hexagonal tools 3 extend beyond the tool container body 552 . The container body 552 includes a first holding wing 560 and a second holding wing 562 . The first holding wing 560 holds a first set of hexagonal tools 570 , and the second holding wing 562 holds a second set of hexagonal tools 572 . The tool container 500 also includes a hanging member 554 for hanging the tool container 500 on an object such as a display rod or hook in a store. In some embodiments, another mechanism for hanging the tool container 500 is implemented. In some embodiments, the tool container 500 also includes a location or cavity for receiving the tool handle 100 . In some embodiments, the tool container 500 includes a location for receiving any tool handle. In some embodiments, the tool container 500 includes raised features 580 for each of the hexagonal tools 3 which allow the user to determine the correct size hexagonal wrench required before removing the tool from the tool container 500 . The user is able to place a fastener over each of the raised features 580 until the correct size tool is determined for that fastener. In some embodiments, labeling of each of the tools is also included on the tool container 500 . The labeling is molded onto the tool container 500 or another implementation.
[0049] As an example, a set of hexagonal wrenches are inserted into the holding wings of the tool container, with the metric tools in one wing and the standard tools in another wing. The tool handle is also inserted into the tool container in an appropriate location. A retaining mechanism is then inserted in between the holding wings of the tool container. The retaining mechanism is a piece of plastic that is configured so that the hexagonal wrenches are not able to be removed while the retaining mechanism is in place. The tool container is closed such that the wings are closed upon the retaining mechanism. The tool container is then secured closed by a securing mechanism such as a zip tie which goes in and around a hanging member of the tool container. The hanging member then enables the tool container to be hung on a hook in a store for display. While in the retail store, the securing mechanism prevents the tool container from being opened, which prevents the retaining mechanism from being removed from the tool container, which prevents the hexagonal wrenches from being removed from the tool container. After a user purchases the tool container which includes the hexagonal wrenches and the tool handle, the user utilizes a device such as a knife, scissors, wire cutters or another device to remove the securing mechanism. After the securing mechanism is removed, the user opens the tool container. Once the tool container is opened, the securing mechanism is able to be removed and is able to be discarded. The tools are then easily removable and re-insertable into the tool container.
[0050] In some embodiments, the retaining mechanism comprises a first flat surface extending in a horizontal direction with a second surface extending in a vertical direction in a first direction at one end of the first flat surface and a third flat surface extending in a vertical direction in an opposite direction at the opposite end of the first flat surface. In some embodiments, the retaining mechanism comprises more than one component such as two oppositely pointing L-shaped components. The retaining mechanism is able to be any configuration and comprise any number of components as long as it is able to retain the tools within the tool container.
[0051] The circular, cylindrical embodiment of the tool handle is utilized to provide better gripping ability of a tool such as a hexagonal wrench. The circular, cylindrical tool handle is utilized by inserting a tool into a proper slot and then moving the lock to secure the tool in place. The tool container is utilized to hold one or more tools along with the tool handle. The tools are easily accessible in the tool container. Furthermore, while available for purchase, such as in a retail store, a retaining mechanism and a securing mechanism ensure that no tools are stolen or otherwise removed from the tool container. After the tool container is purchased, a user removes the securing mechanism and then the retaining mechanism. Then, the user is able to remove, utilize and return the tools as desired.
[0052] In operation, the tool container includes a retaining mechanism and a securing mechanism which are able to be used to allow the tool container and tools to be displayed yet protected from theft or removal without the need for additional packaging. This removes the need for expensive added containment materials such as plastic that goes all around the tool container. Moreover, since the retaining mechanism utilizes less plastic, it is also more environmentally friendly.
[0053] It should further be understood by a person skilled in the art that the tool handle of the present invention is able to be modified or adapted for use with tool drivers and tools having shapes other than hexagonal. Further improvements and modifications which become apparent to persons of ordinary skill in the art only after reading this disclosure, the drawings and the appended claims are deemed within the spirit and scope of the present invention. | A circular, cylindrically shaped tool handle holds multiple sizes of tools. The handle includes one or more holding slots each positioned on the outer surface into which tools are inserted and held. Each holding slot includes one or more contoured compartments in which tools rest when engaged with the handle. Each contoured compartment is of a size and dimension which corresponds to one or more tool sizes. Each contoured compartment is formed about a corresponding receiving hole. A lock is positioned over the contoured compartment to irremovably confine the short leg of the hexagonal wrench within the contoured compartment. Hexagonal shaped tools other than wrenches are able to be used with the handle of the present invention such as screwdrivers and socket wrenches. A tool container stores the tools and the tool handle. | 1 |
BACKGROUND
[0001] The present invention relates to a new slurry pad configuration, such as those used to polish semiconductor devices, to methods of manufacturing same, and to an apparatus used in such manufacture.
[0002] Semiconductor devices, such as, but not limited to, semiconductor-on-insulator (SOI) structures are prepared such that a relatively flat semiconductor layer is available, on which electronic components are formed. SOI technology is becoming increasingly important for use in displays, including organic light-emitting diode (OLED) displays, liquid crystal displays (LCDs), active matrix displays, integrated circuits, photovoltaic devices, thin film transistor applications, etc.
[0003] The semiconductor material most commonly used in semiconductor-on-insulator structures has been silicon. SOI structures may include a thin layer of substantially single crystal silicon (generally 0.05-0.3 microns in thickness but, in some cases, as thick as 5 microns) on an insulating material. The state of the art processes for forming TFTs on polysilicon result in silicon thicknesses on the order of about 50 nm.
[0004] As will be discussed later herein, the silicon layer thickness may adjusted through controlling the process parameters of bonding the silicon layer onto the substrate (e.g., a glass or glass-ceramic substrate). In display applications, the silicon layer thickness is typically in the 50-150 nm range. In addition to silicon layer thickness, the surface roughness of the silicon layer is critical to obtaining high performance TFTs. Surface roughness is typically in the 1-10 nm range just after bonding the silicon layer to the substrate (a so-called “as fabricated” SOI). Thus, post processes are typically carried out to reduce the semiconductor (silicon) layer thickness and to reduce the layer roughness. These processes will be discussed below.
[0005] The SOI abbreviation is used herein to refer to semiconductor-on-insulator structures in general, including, but not limited to, silicon-on-insulator structures. Similarly, the SiOG abbreviation may be used to refer to semiconductor-on-glass structures in general, including, but not limited to, silicon-on-glass and/or silicon on glass-ceramic structures. SOI structures encompass SiOG structures.
[0006] Various ways of obtaining SOI structures include epitaxial growth of silicon (Si) on lattice matched substrates. An alternative process includes the bonding of a single crystal silicon wafer to another silicon wafer on which an oxide layer of SiO 2 has been grown, followed by polishing or etching of the top wafer down to, for example, a 0.05 to 0.3 micron layer of single crystal silicon. Further methods include ion-implantation methods in which either hydrogen or oxygen ions are implanted either to form a buried oxide layer in the silicon wafer topped by Si in the case of oxygen ion implantation or to separate (exfoliate) a thin Si layer to bond to another Si wafer with an oxide layer as in the case of hydrogen ion implantation.
[0007] The former two methods have not resulted in satisfactory structures in terms of cost and/or bond strength and durability. The latter method involving hydrogen ion implantation has received some attention and has been considered advantageous over the former methods because the implantation energies required are less than 50% of that of oxygen ion implants and the dosage required is two orders of magnitude lower.
[0008] U.S. Pat. No. 5,374,564 discloses a process to obtain a single crystal silicon film on a substrate using a thermal process. A silicon wafer having a planar face is subject to the following steps: (i) implantation by bombardment of a face of the silicon wafer by means of ions creating a layer of gaseous micro-bubbles defining a lower region of the silicon wafer and an upper region constituting a thin silicon film; (ii) contacting the planar face of the silicon wafer with a rigid material layer (such as an insulating oxide material); and (iii) a third stage of heat treating the assembly of the silicon wafer and the insulating material at a temperature above that at which the ion bombardment was carried out. The third stage employs temperatures sufficient to bond the thin silicon film and the insulating material together, to create a pressure effect in the micro-bubbles, and to cause a separation between the thin silicon film and the remaining mass of the silicon wafer. (Due to the high temperature steps, this process does not work with lower cost glass or glass-ceramic substrates.)
[0009] U.S. Pat. No. 7,176,528 discloses a process that produces an SiOG structure. The steps include: (i) exposing a silicon wafer surface to hydrogen ion implantation to create a bonding surface; (ii) bringing the bonding surface of the wafer into contact with a glass substrate; (iii) applying pressure, temperature and voltage to the wafer and the glass substrate to facilitate bonding therebetween; and (iv) cooling the structure to a common temperature to facilitate separation of the glass substrate and a thin layer of silicon from the silicon wafer.
[0010] By adjusting the implant energy, the semiconductor (e.g., silicon) layer thickness may be reduced to 300-500 nm if there is no oxide on the silicon surface before implantation, which is desirable for the SiOG process. From 300-500 nm, the thickness of the layer should be reduced to less than about 100 nm.
[0011] The resulting SOI structure just after exfoliation might exhibit surface roughness (e.g., about 10 nm or greater), excessive silicon layer thickness (even though the layer is considered “thin”), and implantation damage of the silicon layer (e.g., due to the formation of an amorphized silicon layer). The amorphized silicon layer may be anywhere from 50-150 nm in thickness and should be removed to obtain desired electronic properties for the later formed electronic components.
[0012] Chemical mechanical polishing (CMP) is a typical process to reduce the thickness of the silicon layer, to reduce the roughness of the silicon layer, and to remove the amorphized silicon layer after the silicon layer has been exfoliated from the donor silicon wafer. CMP for the SiOG structure application is accomplished using abrasive slurries coupled with a textile polishing pad (which is sometimes fibrous) saturated with such abrasive slurry. The slurry is a mixture of abrasive particles and a liquid carrier, which may be de-ionized water. The polishing pad is bonded (via adhesive) to a rotating platen. The SOI structure to be polished and the polishing pad are subjected to a stream of pumped slurry, and the polishing action is accomplished by forcing the abrasive charged polishing pad against the semiconductor material of the SOI, resulting in material removal and subsequent polishing of the semiconductor surface.
[0013] In most cases, both the platen and SOI structure to be polished are in a flat configuration. The polishing pad is formed and assembled to the platen such that the resulting pad surface is smooth and uniform, with no wrinkles or surface irregularities, which would otherwise create problems with the polishing uniformity. In the case of a flat polishing pad, it is a relatively straight forward task to cut and mount the pad to a flat polishing platen. The form of the pad is cut to conform to the contour of the platen (which is flat), and the pad is bonded to the platen with a pressure sensitive adhesive. In most cases, the polishing pads and the platens (and bonnets thereof) are of flat, circular geometry.
[0014] In more recent developments, the polishing pad is mounted on a semi-spherical bonnet that allows tangent tool contact polishing of spherical shapes such as lenses. The tangent tool contact processes can also be used to polish flat surfaces, such as SOI structures. This is commonly performed by deterministic polishing, an abrading process in which the contact area of the polishing pad is substantially smaller that the area of the SOI structure needing polishing. The material removal process is performed by rotating the bonnet (and attached polishing pad) and simultaneously moving it in a predetermined scanning pattern along the contour of the semiconductor layer of the SOI. Although different scanning patterns are available, the most common pattern is a series of closely spaced parallel lines (a raster), similar to the line pattern scanned on a cathode ray tube of a traditional television set.
[0015] The requirements for SOI thinning and roughness reduction are quite stringent. It would be desirable for the final semiconductor layer thickness to be controlled with an accuracy of about ±8 nm. The radius of curvature of the semi-spherical bonnet introduces a challenge as to mounting a flat polishing pad firmly to the radiused bonnet in a smooth fashion with no wrinkles that would adversely effect the polishing process. Wrinkles and/or other polishing pad irregularities may adversely effect the polishing process just as deviations in the rotation of the bonnet have a profound effect on material removal. It will be appreciated that any eccentricity in the polishing pad rotation (from the bonnet itself, wrinkles in the pad, registration problems, etc.) will result in thickness variability in the semiconductor layer. It has been found that bonnet eccentricity alone can result in thickness variability of about 15 nm, which is larger than the desired layer thickness tolerance. Additional irregularities from wrinkles in the polishing pad may significantly increase the variability.
[0016] The conventional technique for forming semi-spherical polishing pads is to cut a circle from sheet material, soften the material with acetone (or a similar solvent), and then press the pad in a two-part mold. The mold includes a bottom mold section having a convex surface and a top mold section having a corresponding concave surface. FIG. 1 illustrates the prior art semi-spherical pad 10 after the top mold has been removed. Note the wrinkles 12 at the peripheral edge of the pad 10 .
[0017] In view of the foregoing, there is a need in the art for new methods and apparatus for producing a semi-spherical polishing pad.
SUMMARY
[0018] In accordance with one or more embodiments, the geometry of a polishing pad includes an outside diameter to fit the dimensions of an existing semi-spherical bonnet, and an inside diameter defining a central aperture. A set of equally spaced radial slots on the outside diameter of the pad allows material relief, eliminating material gathering once molded and attached to the bonnet. This reduces material wrinkles and allows for a smoother fit. The central aperture of the pad allows more material flexibility in the pad reducing wrinkles and also provides a feature that allows a referencing button (fabricated of a material that is harder than the pad material) to be placed on the bonnet, which is used to set the tool axis position in relation to the surface to be polished.
[0019] Prior to forming, the polishing pad is conditioned by rolling it over an edge (such as an edge of a tabletop) in multiple radial directions, yielding the pad fibers, reducing material memory, and allowing the pad to become more flexible and compliant to the convex shape of the bonnet. The pad material is saturated with solvent to make it more flexible and compliant, and then pressed over the bonnet form (as the bottom mold section). A flexible bladder, air-filled pneumatic bladder is pressed onto the pad opposite the bonnet form, which when inflated to pressure, allows an even pneumatic force to be applied to the pad. The pressing technique allows uniform compliance of the pad to the bonnet form, yielding less pad irregularity, and greater polishing precision and predictability.
[0020] In accordance with one or more embodiments of the present invention, a polishing pad for polishing semiconductor surfaces, includes a circular body having a center and an outer peripheral edge; and a plurality of slots extending from the outer peripheral edge towards the center. The body is in a semi-spherical, domed shape.
[0021] The plurality of slots may include a width that is substantially constant along a length thereof when the polishing pad is in a flat orientation. Alternatively, the width may taper along a length thereof from the peripheral edge toward the center when the polishing pad is in a flat orientation. When 12 slots are employed, they may be disposed evenly about the perimeter of the body, each at an angle of about 30 degrees from one another. When 6 slots are employed they may be disposed evenly about the perimeter of the body, each at an angle of about 60 degrees from one another.
[0022] The polishing pad may include an aperture disposed at the center of the body.
[0023] In accordance with one or more further embodiments of the present invention, an apparatus for forming a semi-spherical polishing pad for polishing semiconductor surfaces includes: a first platen; a bonnet form, coupled to the first platen and having a dome-shaped forming surface directed away from the first platen and operable to receive a polishing pad pre-form; a second platen spaced apart from the first platen; a bladder coupled to the second platen and facing the dome-shaped forming surface of the bonnet form; and a press mechanism coupled to the first and second platens and operable to urge the first and second platens toward one another to facilitate engagement of the bladder against the polishing pad pre-form.
[0024] The press mechanism is operable to move the second platen a distance toward the first platen to dispose the bladder at a predetermined distance from the dome-shaped forming surface of the bonnet form. The press mechanism may include one or more clamps that lock the first and second platens such that the bladder is at the predetermined distance.
[0025] The bladder is operable to impart a controllable force in response to variations in fluid pressure such that the dome-shaped forming surface of the bonnet form presses against the polishing pad pre-form from one side and the bladder presses against the polishing pad pre-form from an opposite side. The fluid may be a liquid or a gas, such as air.
[0026] The use of the apparatus includes: placing a polishing pad pre-form on a dome-shaped forming surface; disposing the bladder opposite to the dome-shaped forming surface and the polishing pad pre-form; inflating the bladder with a fluid such that the dome-shaped forming surface of the bonnet form presses against the polishing pad pre-form from one side and the bladder presses against the polishing pad pre-form from an opposite side; and maintaining the pressing step for a predetermined period of time to achieve the semi-spherical polishing pad. The pressure within the bladder may be increased to about 1 Bar during the inflating step. Prior to placing the polishing pad pre-form on the dome-shaped forming surface, the pad pre-form may be rolled and/or dragged over a straight edge in multiple radial directions such that material fibers of the polishing pad pre-form yield and the polishing pad pre-form becomes more flexible. Additionally or alternatively, the pad pre-form may be soaked with a solvent such that the polishing pad pre-form becomes more flexible.
[0027] Other aspects, features, advantages, etc. will become apparent to one skilled in the art when the description of the invention herein is taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] For the purposes of illustrating the various aspects of the invention, there are shown in the drawings forms that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
[0029] FIG. 1 is a perspective view of a polishing pad in accordance with the prior art;
[0030] FIG. 2 is a top, schematic view of a pre-form cut out for a polishing pad in accordance with one or more embodiments of the present invention;
[0031] FIG. 3 is a top, schematic view of a pre-form cut out for an alternative polishing pad in accordance with one or more further embodiments of the present invention;
[0032] FIGS. 4 , 5 , and 6 are perspective, and partial cut away views of an apparatus for forming a polishing pad in accordance with one or more embodiments of the present invention;
[0033] FIG. 7 is a perspective view of a formed polishing pad from the cut-out of FIG. 2 in accordance with one or more embodiments of the present invention; and
[0034] FIG. 8 is a perspective view of a formed polishing pad from the cut-out of FIG. 3 in accordance with one or more embodiments of the present invention.
DETAILED DESCRIPTION
[0035] With reference to the drawings, wherein like numerals indicate like elements, there is shown in FIG. 2 a polishing pad pre-form 20 for use in tangent tool contact polishing of spherical shapes, such as lenses, flat surfaces, such as SOI structures, etc. Although the polishing pad pre-form 20 is flat, after a forming process a semi-spherical, domed-shape will result, which is the intended configuration for the tangent tool contact polishing. The polishing pad pre-form 20 includes a circular body 22 having a center 24 , and an outer peripheral edge 26 . The specific material of the pad pre-form 20 may be selected from any of the known materials and suppliers.
[0036] A plurality of slots 28 extend from the outer peripheral edge 26 radially towards the center 24 . As will be discussed in more detail below, the slots 28 allow material relief, eliminating material gathering once the pad pre-form 20 is molded and attached to a bonnet of the tangent tool (not shown). This reduces material wrinkles and allows for a smoother fit. In the embodiment illustrated in FIG. 2 , the slots 28 each include a width that is substantially constant along a length thereof. In this embodiment, the plurality of slots 28 are disposed evenly about the peripheral edge 26 of the body 22 such that the slots 28 are at an angle of about 30 degrees from one another.
[0037] The specifics of the slot 28 details of this embodiment may be expressed in several ways, such as absolute dimensions, relative dimensions, etc. For example, the width of the slots 28 may be about 0.1 to about 0.4 inches, while the length of the slots 28 may be about 0.25 to about 0.5 inches. In relative terms, the width of the slots may be about 20%-160% of the length thereof. Relative to the diameter of the body 22 , the width of the slots may be about 2% to about 10% of the diameter, while the length of the slots may be about 6% to about 15% of the diameter. In this particular configuration, the diameter of the body 22 is about 4 inches (although it is understood that other diameters are contemplated.
[0038] An aperture 29 is disposed at the center 24 of the body 22 and is preferably of circular configuration. The dimensions of the aperture 29 may be expressed in absolute or relative terms. For example, a diameter of the aperture may be about 0.5-1.0 inches, or about 15%-25% of the diameter of the body 22 . The removal of material from the center 24 of the pad pre-form 20 allows more material flexibility in the body 22 , which reduces wrinkles in the final formed pad (which will be discussed in more detail below).
[0039] With reference to FIG. 3 , an alternative polishing pad pre-form 30 is illustrated, again for use in tangent tool contact polishing. Again, although the polishing pad pre-form 30 is flat, after a forming process a semi-spherical, domed-shape will result. The polishing pad pre-form 30 includes a circular body 32 having a center 34 , and an outer peripheral edge 36 . Again, a plurality of slots 38 extend from the outer peripheral edge 36 radially towards the center 34 . In this embodiment, the slots 38 each include a width that tapers along a length thereof from the peripheral edge 36 toward the center 34 when the polishing pad pre-form 30 is in a flat orientation. In this embodiment, the plurality of slots 38 are disposed evenly about the peripheral edge 36 of the body 32 such that the slots 38 are at an angle of about 60 degrees from one another.
[0040] The details of the slots 38 of this embodiment of the pad pre-form 30 include that the width of the slots 38 are about 0.1 to about 0.4 inches at the peripheral edge 36 (e.g., when the diameter of the pad perform is about 4 inches). The length of the slot 38 may be about 0.5-1.5 inches. The slots 38 may taper to a point, be rounded, or may be cut straight across. In relative terms, the width of the slots 38 at the peripheral edge 36 may be about 6%-80% of the length thereof. With respect to the diameter of the body 32 , the width of the slots 38 at the peripheral edge may be about 2% to about 10% of the diameter, and the length of the slots 38 may be about 12% to about 40% of the diameter.
[0041] FIGS. 4-6 illustrate an apparatus 50 for forming a semi-spherical polishing pad 20 A from pad pre-forms, such as the pad perform 20 or the pad pre-form 30 discussed above. The apparatus 50 includes first and second platens 100 , 200 that are spaced apart from one another. The second platen 200 is moveable relative to the first platen 100 (although in other embodiments this function may be reversed or both platens may be movable). The first platen 100 is operable to releasably receive a bonnet form 102 . The bonnet form 102 includes a dome-shaped forming surface 104 directed away from the first platen 100 and operable to receive the polishing pad pre-form 20 .
[0042] The second platen 200 is operable to receive a bladder 202 that faces the dome-shaped forming surface 104 of the bonnet form 102 . An inflation port 206 communicates with an interior volume of the bladder 202 to deliver and remove a fluid (a liquid or a gas, such as air) therefrom. As best seen from the cross-sectional view of FIG. 5 , the bladder 202 includes an engagement surface 208 that presses against the pad pre-form 20 , to varying degrees as the pressure in the bladder 202 increases. When the platens 100 , 200 are spaced far apart (as in FIGS. 4 and 5 ), the engagement surface 208 of the bladder 202 achieves a convex shape, as would be expected in a balloon-type device.
[0043] The apparatus 50 includes a press mechanism that is operable to move the second platen 200 a distance toward the first platen 100 to dispose the bladder 202 at a predetermined distance from the dome-shaped forming surface 104 of the bonnet form 102 . The press mechanism includes one or more alignment rods 300 , fixed in the first platen 100 and slideably received in apertures 302 of the second platen 200 . The press mechanism also includes one or more clamps 304 A, 304 B, 304 C, fixed in the first platen 100 , that engage the second platen 200 (via complementary mechanisms) and lock the first and second platens 100 , 200 such that the bladder 202 is at the predetermined distance. The locks 304 may be implemented using threaded bolts and complementary threaded posts.
[0044] When the platens 100 , 200 are spaced close to one another (as in FIG. 6 ), the engagement surface 208 of the bladder 202 presses against the polishing pad pre-form 20 , 30 . The shape of the bladder 202 (and the engagement surface 208 thereof) reverses from the convex to concave, to complement the shape of the dome-shaped forming surface 104 of the bonnet form 102 and the pad pre-form 20 , 30 . In response to varying quantities and/or pressures of the fluids introduced through the port 206 , the bladder 202 is operable to impart a controllable force such that the dome-shaped forming surface 104 of the bonnet form 102 presses against the polishing pad pre-form 20 , 30 from one side and the engagement surface 208 of the bladder 202 presses against the polishing pad pre-form 20 , 30 from an opposite side. The pressure within the bladder 202 may be increased to about 1 Bar to provide sufficient force (for a predetermined time) to achieve the dome-shaped pad.
[0045] Prior to placing the polishing pad pre-form 20 , 30 on the dome-shaped forming surface 104 of the bonnet form 102 , the pad perform 20 , 30 may be rolled and/or dragged over a straight edge in multiple radial directions such that material fibers of the polishing pad pre-form 20 , 30 yield and the polishing pad pre-form 20 , 30 becomes more flexible. Additionally or alternatively, prior to placement of the pad pre-form 20 , 30 on the dome-shaped forming surface 104 , the polishing pad pre-form 20 , 30 may be soaked with a solvent to increase the flexibility thereof.
[0046] FIG. 7 illustrates the formed polishing pad 20 A, when the pad pre-form 20 is used in the apparatus 50 . Note that there is no wrinkling at the peripheral edge 26 as was the case in the prior art. The central aperture 29 of the pad 20 A allows more material flexibility, thereby reducing wrinkles. The aperture 29 also provides a feature that allows a referencing button 70 (fabricated of a material that is harder than the pad material) to be placed on the dome-shaped forming surface 104 of the bonnet 103 . The button 70 is used to set the tool axis position in relation to the surface to be polished. The button 70 is used to fill the central aperture 29 and should be of like thickness to the formed polishing pad 20 A. The button 70 may be of magnitudes stiffer material to prevent compression during a probing function. The probing function sets the position of the polishing pad surface relative to the part surface (the part to be polished) to be able to control the amount of polishing pressure applied to the part surface. Also the probing function will detect the geometry errors of the part surface in relation to the machine axis and allow for compensation during the polishing motions. The button 70 makes contact with the part surface at one or multiple points and machine control receives feedback from sensors in the machine axis to determine part and polish pad positions. During probing, the axis is fed into the component until an axis load cell of the polishing apparatus detects a trigger load. When the trigger load is detected, the axis position is recorded. This touch load/position sensing is used to electronically map the part surface. The harder center button 70 results in a smaller repeatability error when being used to probe the part surface. If the center button 70 were significantly compressible, it would result in a non-repeatable probe trigger load, which in turn would result in a position repeatability error. The textured polishing pad tends to result in mapping errors of several microns.
[0047] FIG. 8 illustrates the formed polishing pad 30 A, when the pad pre-form 30 is used in the apparatus 50 . Note again that there is no wrinkling at the peripheral edge 36 as was the case in the prior art.
[0048] The forming apparatus 50 can also be used for gluing the formed polishing pad 20 onto a polishing bonnet 103 . This is achieved by removal of the bonnet form 102 ( FIG. 5-6 ) and installation of a polishing bonnet 103 ( FIG. 7 ) onto the first platen 100 . Adhesive is placed on the appropriate surfaces of the bonnet 103 prior to, or after mounting same onto the first platen 100 . The bonnet 103 , being formed of a flexible material, is inflated to a desired working pressure via a fluid fitting (port) 106 in the first platen 100 . The formed polishing pad 20 is placed lightly on the bonnet 103 . Next, the second platen 200 is lowered and locked in place in the same way as in the formation of the polishing pad 20 (discussed above). The pressure inside the pneumatic bladder 202 may be adjusted to evenly distribute the load and press the pad 20 in place with no wrinkles or loose adhesive zones.
[0049] 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. | Methods and apparatus for forming a semi-spherical polishing pad for polishing semiconductor surfaces, provide for: placing a polishing pad pre-form on a dome-shaped forming surface, the polishing pad pre-form including a circular body having a center and an outer peripheral edge, and a plurality of slots extending from the outer peripheral edge towards the center; disposing a bladder opposite to the dome-shaped forming surface and the polishing pad pre-form; inflating the bladder with a fluid such that the dome-shaped forming surface of the bonnet form presses against the polishing pad pre-form from one side and the bladder presses against the polishing pad pre-form from an opposite side; and maintaining the pressing step for a predetermined period of time to achieve the semi-spherical polishing pad. | 8 |
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] This invention was made in part with Government support under CRADA No. 02N-050 between Woodward Governor Company and the National Energy Technology Laboratory of the United States Department of Energy. The Government has certain rights in this invention.
FIELD OF THE INVENTION
[0002] The present invention relates generally to continuous combustion systems, and more particularly relates to such systems operating near the onset of combustion instability.
BACKGROUND OF THE INVENTION
[0003] Continuous combustion systems such as gas turbine engines are used in a variety of industries. These industries include transportation, electric power generation, and process industries. During operation, the continuous combustion system produces energy by combusting fuels such as propane, natural gas, diesel, kerosene, or jet fuel. One of the byproducts of the combustion process is emission of pollutants into the atmosphere. The levels of pollutant emissions are regulated by government agencies. Despite significant reductions in the quantity of environmentally harmful gases emitted into the atmosphere, emission levels of gases such as NO x , CO, CO 2 and hydrocarbon (HC) are regulated by the government to increasingly lower levels and in an ever increasing number of industries.
[0004] Industry developed various methods to reduce emission levels. One method for gaseous fueled turbines is lean premix combustion. In lean premix combustion, the ratio between fuel and air is kept low (lean) and the fuel is premixed with air before the combustion process. The temperature is then kept low enough to avoid formation of nitrous oxides (which occurs primarily at temperatures above 1850 K). The premixing also decreases the possibility of localized fuel rich areas where carbon monoxides and unburnt hydrocarbons are not fully oxidized.
[0005] One of the more difficult challenges facing manufacturers of lean premix gas turbines and other continuous combustion systems is the phenomenon of combustion instability. Combustion instability is the result of unsteady heat release of the burning fuel and can produce destructive pressure oscillations or acoustic oscillations. In lean premix gas turbines, combustion instability can occur when the air-fuel ratio is near the lean flammability limit, which is where turbine emissions are minimized and efficiency is maximized. In general, the air/fuel ratio of the premixed fuel flow should be as lean as possible to minimize combustion temperatures and reduce emissions. However, if the air/fuel ratio is too lean, the flame will become unstable and create pressure fluctuations. The typical manifestation of combustion instability is the fluctuation of combustion pressure sometimes occurring as low as ±1 psi at frequencies ranging from a few hertz to tens of kHz. Depending on the magnitude and frequency, this oscillation can create an audible noise which is sometimes objectionable, but a much more serious effect can be catastrophic failure of turbine components due to high cycle fatigue. The most severe oscillations are those that excite the natural frequencies of the mechanical components in the combustion region, which greatly increases the magnitude of the mechanical stress.
[0006] Most continuous combustion systems are commissioned in the field with sufficient safety margin to avoid entering an operating regime where combustion instabilities can occur. However, as components wear out or fuel composition changes, the combustion process can still become unstable.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention provides an apparatus and method to sense the presence of combustion instability, even at very low levels.
[0008] An ion sensor such as an electrode is positioned in the combustion chamber of a turbine combustion system at a location such that the sensor is exposed to gases in the combustion chamber. A voltage is applied to the sensor to create an electric field from the sensor to a designated ground (e.g., a chamber wall) of the combustion chamber. The voltage is applied in one embodiment such that the electric field radiates from the sensor to the designated ground of the combustion chamber. A control module detects and receives from the sensor a combustion ionization signal and determines if there is an oscillation in the combustion ionization signal indicative of the occurrence of combustion instability or the onset of combustion instability.
[0009] The control module applies a voltage to the sensor during the combustion process, measures the ion current flowing between the sensor and the designated ground of the combustion chamber, and compares the ionization current oscillation magnitude and oscillation frequency against predetermined parameters and broadcasts a signal if the oscillation magnitude and oscillation frequency are within a combustion instability range. The parameters include an oscillation frequency range and an oscillation magnitude.
[0010] The signal is broadcast to indicate combustion instability if the oscillation frequency is within a critical range for a given combustion system (e.g., the range of approximately 250 Hz to approximately 300 Hz for a critical frequency of 275 Hz) and/or the oscillation magnitude is above a first threshold relative to a steady state magnitude (e.g., ±2 psi). The signal is broadcast to indicate the onset of combustion instability if the oscillation frequency is within the critical range and/or the oscillation magnitude is above a second threshold relative to a steady state magnitude.
[0011] A redundant sensor held in a coplanar but spaced apart manner by an insulating member from the ion sensor provides a combustion ionization signal to the control module when the ion sensor fails.
[0012] These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] 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:
[0014] [0014]FIG. 1 is a diagram illustrating the components of the present invention in a portion of a turbine system;
[0015] [0015]FIG. 2 a is a cross-sectional view of the electrode component of one embodiment of the present invention integrated into a fuel nozzle body;
[0016] [0016]FIG. 2 b is a cross-sectional view of an alternate embodiment of the electrode component of the present invention integrated into a fuel nozzle body
[0017] [0017]FIG. 3 is a diagram illustrating the components of FIG. 1 in a system having combustion instability;
[0018] [0018]FIG. 4 is a diagram illustrating the components of FIG. 1 in a system having combustion instability in a combustion chamber having electrically insulated walls;
[0019] [0019]FIG. 5 is a graphical illustration of the output of a pressure sensor and ion current illustrating that ion current oscillations correspond to pressure oscillations in a combustion chamber; and
[0020] [0020]FIG. 6 is a diagram illustrating that the dominant frequencies of ion current oscillations track surges in pressure oscillations in a combustion chamber.
[0021] While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention provides a method and apparatus to sense combustion instability and/or the onset of combustion instability in a combustion region of a continuous combustion system such as a gas turbine, industrial burner, industrial boiler, or afterburner utilizing ionization signals. The magnitude of the ionization signal is proportional to the concentration of hydrocarbons in the flame. Oscillations in the flame produce oscillations in the hydrocarbons, which in turn, results in oscillations in the ionization signal. The invention detects the frequency and magnitude of oscillations in the ionization signal and provides an indication when the frequency and magnitude of the ionization signal oscillation are above selected thresholds.
[0023] Turning to the drawings, wherein like reference numerals refer to like elements, the invention is illustrated as being implemented in a suitable turbine environment. FIG. 1 illustrates an example of a suitable turbine environment 100 on which the invention may be implemented. The turbine environment 100 is only one example of a suitable turbine environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. For example, the invention may be implemented in an afterburner, industrial burner, industrial boiler, and the like. Neither should the turbine environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100 .
[0024] With reference to FIG. 1, an exemplary system for implementing the invention includes electronic module 102 , fuel nozzle 104 , and combustion chamber 106 . The fuel nozzle 104 is mounted to the combustion chamber 106 using conventional means. The fuel nozzle 104 is typically made of conducting material and has an inlet section 108 , an outlet port 110 that leads into combustion chamber 106 and a center body 112 . An ignitor (not shown) is used to ignite the fuel mixture in the combustion region after the air and fuel are mixed in a pre-mix swirler 114 . In afterburners, the air enters combustion chamber 106 through separate passages and a fuel nozzle passage is used to introduce fuel in the combustion chamber 106 . The operation of the turbine is well known and need not be discussed herein.
[0025] The electronic module 102 may be a separate module, part of an ignition control module or part of an engine control module. The electronic module 102 includes a power supply 130 for providing a controlled ac or dc voltage signal to the electrodes 120 , 122 when commanded by processor 132 . Processor 132 commands the power supply to provide power to the electrodes 120 , 122 , receives ion current signals from electrodes 120 , 122 via conditioning module 136 , performs computational tasks required to analyze the ion signals to determine the onset of combustion instability and combustion instability, and communicates with other modules such as an engine control module through interface 134 . Conditioning module 136 receives signals from the electrodes 120 , 122 via lines 138 and performs any required filtering or amplification.
[0026] Turning now to FIG. 2 a, an embodiment 118 of the ion sensor of the present invention includes circular combustion electrode 120 , redundant electrode 122 , and insulating members 124 . The electrodes 120 and 122 are made of an electrically conducting material, such as a metal that is capable of withstanding the normal operating temperatures produced in a combustion system. The material should also be able to withstand the high temperatures presented during abnormal conditions such as a flashback condition.
[0027] The insulating member 124 is made of a non-conducting, rugged material, such as an insulated ceramic oxide material, that is able to withstand both the normal operating temperatures produced during fuel combustion as well as the high temperatures presented during a flashback condition. The insulating member 124 has a circular shape with a smooth surface. The electrodes 120 , 122 are securely seated between the insulating member 124 in electrical and physical isolation from one another, but in such manner that a significant portion of the face of each electrode 120 , 122 is exposed such that the electrodes 120 , 122 can detect the ionization flame field surrounding the combustion in order to determine combustion instability. The electrodes 120 , 124 are electrically charged by coaxial cables 126 , 128 . Alternatively, the insulating member 124 may be an integral part of the center body 112 or located at other points of the fuel nozzle 104 . FIG. 2 b shows an alternate embodiment of the electrodes 120 , 122 where the surface area of electrode 120 is maximized by using the entire tip of the center body 112 . Further details of the construction of the electrodes 120 , 122 are described in U.S. Pat. No. 6,429,020 and U.S. patent application Ser. No. 09/955,582 filed on Sep. 18, 2001, hereby incorporated by reference in their entireties.
[0028] It should be noted that other types of ion current sensors may be used in accordance with the present invention. For example, a single electrode may be used. Additionally, other types of electrodes may be used that are capable of sensing ion current in continuous combustion systems. In the description that follows, the electrodes 120 , 122 shall be used to describe the operation of the invention.
[0029] Turning now to FIG. 3, during normal combustion, the flame 140 produces free ions and the electrode 120 will have an ion current flow when a voltage is applied to the electrode 120 . Ion current will flow between the electrode 120 and ground (e.g., the chamber wall). The magnitude of the ion current flow will be in proportion to the concentration of free ions in the combustion process. When a voltage potential is applied to electrode 120 , 122 , an electric field 142 ( 144 ) is established between the electrode 120 and the remaining components in the combustion chamber. The purpose of the electrode 122 is to serve as a redundant sensor. During normal operation, the electric field 144 in electrode 122 points rearward toward the swirler 114 due to the canceling effect of the electric field 142 produced by electrode 120 . In the event that electrode 120 or the corresponding circuitry for electrode 120 fails, electrode 122 may be used and it will sense substantially the same ion current of electrode 120 because there is no cancellation of electric fields by electrode 120 . For combustion chambers having walls that are electrically insulated or are poorly grounded, a grounding strip is used to provide a return path to enhance the flow of ion current. The term grounding strip as used herein means any connection that provides a return path to ground. For example, the grounding strip may be a ground plane, a conductive strap, a conductive strip, a terminal strip, etc. It should be noted that the electrodes 120 , 122 may also be used as a guard electrode and flashback sensor as described in U.S. Pat. No. 6,429,020 and U.S. patent application Ser. No. 09/955,582.
[0030] Once the flame 140 begins to oscillate, the ionization field surrounding the flame will also oscillate. The electronic module 102 senses the oscillation and takes appropriate action if the oscillation magnitude and frequency are above threshold levels as described below. Turning now to FIG. 4, the oscillations in pressure and in ion current are shown. In FIG. 4, curve 400 illustrates a pressure oscillation from a pressure sensor mounted in a combustion chamber having the electrodes 120 , 122 . Curve 402 is the ion current flowing through electrode 120 and curve 404 is the ion current flowing through electrode 122 . In the event that electrode 120 fails, the ion current flowing through electrode 122 will be similar to curve 402 . It can be seen that the ion current can provide a direct indication of pressure oscillations in the combustion chamber. FIG. 5, which is a fast Fourier transformation (FFT) of FIG. 4, illustrates that the dominant frequencies of the ion current 402 tracks the dominant frequencies of pressure 400 over various operating conditions in the combustion chamber 106 .
[0031] When the flame 140 becomes unstable, it will typically exhibit pressure oscillations ranging in frequency from a few Hz to 2000 Hz and higher. Oscillations with amplitudes as low as ±1 psi are capable of producing audible noise that cannot be tolerated in some cases. In addition to noise, the pressure oscillation waves can create mechanical stress in the system, leading to premature failure and even catastrophic failure. The combustion chamber liner and turbine blades (not shown) are most susceptible to high fatigue stress caused by combustion oscillations.
[0032] Turning now to FIG. 6, the steps the electronic module performs in detecting the onset of combustion instability is illustrated Setpoints (i.e., thresholds) are determined by an operator and are stored in an engine control module or other control module such as an ignition control module and received by the electronic module (step 600 ). The setpoints include oscillation magnitude and frequency thresholds that the control module is to detect. For example, the thresholds could be for the onset of combustion instability, a shut down level (e.g., destructive combustion instability), etc. For purposes of explanation, two thresholds will be used. Those skilled in the art recognize that any number of thresholds may be used. The thresholds used for explanation are a first threshold and a second threshold. The first threshold is for the onset of combustion instability where the oscillation frequency and magnitude are in a region where control parameters can be changed to move the combustion system operation away from the unstable range. The second threshold is for conditions where emergency actions must be performed such as reducing the power or shutdown the system to protect the system because further operation can lead to serious mechanical failure.
[0033] The electrode 120 is energized at the appropriate point in the cycle (step 602 ). Typically, the electrode 120 is energized after (or when) the fuel/air mixture is ignited. Electronic module 102 receives the ion waveform and processes the waveform (step 604 ). The waveform processing includes detecting if there is any oscillation in the waveform. If there is oscillation, the magnitude and frequency of oscillation is determined. If the oscillation magnitude is above the first threshold and below the second threshold (step 606 ), the frequency is checked to determine if it is within the frequency band setpoint for the first threshold (step 608 ). If the oscillation frequency is within the frequency band, a notice is sent to the engine control module so that control parameters can be changed such that the turbine operates further away from the point of combustion instability (step 610 ).
[0034] If the oscillation exists, the module 102 determines if the oscillation magnitude is above the second threshold level (step 612 ). If the oscillation magnitude is above the second threshold, the module determines if the frequency is within the frequency band setpoint for the second threshold (step 614 ). If the oscillation frequency is within the frequency band, an alarm is sent so that appropriate action can be taken such as shutting down the combustion system or derating the system output to avoid damage to the combustion system (step 616 ). In some continuous combustion systems, the notice and/or alarm is sent if the magnitude is above the threshold or the frequency is within the frequency band.
[0035] It can therefore be seen that a method and apparatus to detect combustion instability has been described. The need for a pressure sensor to sense combustion instability is eliminated using the present invention. Life-time maintenance costs of the turbine system is reduced with the elimination of the pressure sensor. The control components may be separately housed or be integrated into existing turbine control modules.
[0036] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
[0037] Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. | An apparatus and method to sense the onset of combustion stability is presented. An electrode is positioned in a turbine combustion chamber such that the electrode is exposed to gases in the combustion chamber. A control module applies a voltage potential to the electrode and detects a combustion ionization signal and determines if there is an oscillation in the combustion ionization signal indicative of the occurrence of combustion stability or the onset of combustion instability. A second electrode held in a coplanar but spaced apart manner by an insulating member from the electrode provides a combustion ionization signal to the control module when the first electrode fails. The control module broadcasts a notice if the parameters indicate the combustion process is at the onset of combustion instability or broadcasts an alarm signal if the parameters indicate the combustion process is unstable. | 5 |
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application, Ser. No. 08/091,859, filed Apr. 26, 1993, now abandoned.
FIELD OF INVENTION
This invention relates generally to the coating of semirigid, somewhat flexible materials with a thermoplastic adhesive in powder form which will reactivate and refers more particularly to a method of applying the adhesive powder in a uniform pattern to the surface of porous materials such as cellular or fibrous sheets and panels by bridging the surface of cells or fibers with the small particles of adhesive. The resultant coating of adhesive has minimal effect on porosity of materials and will permit a quality second step lamination with a minimum amount of adhesives.
BACKGROUND OF THE INVENTION
Cellular and fibrous materials coated with an adhesive which can be reactivated are used in a variety of applications. For example, automotive trim panels including headliners can be made by using an adhesive coated panel as a shell or substrate and laminating a decorative cover to the adhesive coated side of the panel. These adhesive coated panels can also be used in the manufacture of other automotive products such as floor pads, hood liners, trunk liners, seating and door panels.
Adhesives can be applied to cellular or fibrous material in many ways, including sprinkling dry adhesive powder, spraying and hot melt printing. It is important to control the amount of adhesive applied in order to avoid waste and disposal problems and also to avoid penetration of the adhesive into the cell and fiber structure of the material. Excess adhesive which finds its way into the cells and fibrous structure of the material often has an undesirable effect on the laminated composite and also increases quantity required and the cost of same.
The particle size of dry adhesive powder is usually small and when applied by sprinkling, much of the adhesive will drop into the cells or fibrous structure of the material rather than remain on the surface where it is needed to provide a second step quality lamination.
In conventional spray methods, multiple overlapping nozzles are used to provide continuous coverage. Overspray beyond the edges of the material is often considered necessary, also to insure continuous coverage. However, the use of overlapping nozzles and overspraying results in waste and disposal problems. Also, adhesive applied in liquid form penetrates into the cell and fiber structure of the material.
Methods of coating materials with adhesive are disclosed in U.S. Pat. No. 4,055,688 to Caratsch, U.S. Pat. No. 4,264,644 to Schaetti, U.S. Pat. No. 4,571,351 to Schaetti, U.S. Pat. No. 4,139,613 to Hefele and U.S. Pat. No. 4,815,660 to Boger. Caratsch (U.S. Pat. No. 4,055,688) in a first step elevates temperature of the adhesive "to its sinter temperature". The adhesive is then transferred onto the surface of a heated printing roll and as the flexible material passes between the printing roll and a contact pressure roll, the adhesive is then released onto the surface of the web material that is in contact with the printing roll.
The process disclosed in Schaetti (U.S. Pat. No. 4,264,644) uses an engraved roller to apply a specified pattern of synthetic powdered adhesive to a flexible textile material. Thermoplastic adhesive is dispensed from a supply container onto an engraved roller and the flexible textile is heated with radiant heat to a temperature sufficient to melt the adhesive and allow same to adhere to the textile and release from the water cooled printing roll.
The method disclosed by Schaettl (U.S. Pat. No. 4,571,351) for coating a flexible cloth with a synthetic powdery product dispenses powdered adhesive from a reservoir onto the surface of an engraved roller which has been preheated with non-contact radiant heaters. The cloth is brought around a second roller which applies pressure to the cloth and presses it into recesses in the engraved roller to pick up the softened adhesive.
The process disclosed in Hefele (U.S. Pat. No. 4,139,613) is for the application of thermoplastic powdered adhesive onto the outer surface of a flexible textile or foam. This process teaches a method of application of two layers of adhesive, superposed one on the other onto a flexible material. This process also uses an engraved roller or other method which provides a predetermined quantity of adhesive with a fixed pattern.
The method in Boger (U.S. Pat. No. 4,815,660) is for spraying hot melt adhesive using at least two spray guns. The spray from the nozzles of these spray guns would have to overlap making it difficult to maintain uniformity of coverage.
SUMMARY OF THE INVENTION
This invention concerns the method of applying thermoplastic adhesive in powder form to the surface of semi-rigid although somewhat flexible open or closed cell foam or fibrous materials which are constructed as by a needle punching or weaving process. The method may also be used on materials made of randomly orientated fibers which are bound together by a thermoplastic fiber, thermoplastic adhesive in the form of web, spray and powder or various latex and heat set adhesives.
In accordance with the preferred method to be described more fully hereinafter, powdered adhesive is applied to the surface of a transport belt which may be composed of a woven, glass fiber reinforced, synthetic resinous material or Kevlar® fabric and is coated with a synthetic resin such as polytetrafluoroethylene (TFE) or fluorinated ethylenepropylene (FEP) manufactured and sold by DuPont under the trademark Teflon® to seal the surface of the belt and make it "nonporous". As the powdered adhesive is dispensed very uniformly onto the belt in quantities as low as 2 grams per square foot, it is important that nothing make contact with or disturb the adhesive particles prior to the preheat station where the adhesive is preheated and "tacked" to the carrier belt before placing material to be coated on the belt in contact with the adhesive. The belt and adhesive move forward through the preheating station and by the use of conductive and/or radiant heaters, the temperature of the adhesive is elevated sufficiently to make it tacky and cause it to adhere to the Teflon® coating on the belt. As the adhesive is not fully melted in the heat station, the positioning of precut substrate material is therefore easier to accomplish.
Foam or fibrous material is placed on the adhesive coated belt and the material/adhesive composition moves forward and through a heating zone and nip rollers in which a predetermined space is required to control substrate thickness during heating. Elevated temperature in the heating zone is used to fully melt the adhesive and cause same to spread or "web" and adhere to the surface of the materials.
The belts, adhesive and material continue to move forward through a cooling station which also has a predetermined space between upper and lower cooling segments to maintain the thickness of the substrate material. Cooling will sufficiently reduce the temperature to resolidify the adhesive and enable the adhesive to remain adhered to the material and release from the surface of the Teflon® covered belt upon exit of the adhesive coated material from the machine.
The application of a water mist or vapor to the surface of the belt prior to application of the adhesive reduces the required activation temperature of the adhesive and also helps to prevent adhesive "bounce" and thereby enhances uniformity of coverage.
An object of this invention is to provide a method of applying adhesive to materials having the foregoing features.
Another object is to provide a method which employs only a few relatively simple steps, can be carried out with equipment which is inexpensive and readily available, reduces quantity and cost of adhesive and produces an end product of high quality.
Other objects, features and advantages will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of apparatus used in the practice of the method of this invention.
FIG. 2 is a fragmentary side elevational view of the vapor misting station showing water being sprayed on the top surface of the transport belt.
FIG. 3 is a fragmentary side elevational view showing the adhesive powder being dispensed onto the transport belt.
FIG. 4 is a sectional view, with parts broken away and the frame partially removed, of portions of the apparatus including the heating, cooling and unloading stations.
FIG. 5A is an enlarged photographic view of foam material to which powdered adhesive has been applied by the process of this invention.
FIG. 5B is an enlarged photographic view of fibrous material to which powdered adhesive has been applied by the process of this invention.
FIG. 6A is an enlarged photographic view of foam material to which powdered adhesive has been applied by a prior art sprinkling process.
FIG. 6B is an enlarged photographic view of fibrous material to which powdered adhesive has been applied by a prior art sprinkling process.
DETAILED DESCRIPTION
Referring now more particularly to the drawings, and especially to FIG. 1, an elongated, endless transport or support belt 10 extends over a pair of parallel, horizontal rollers 12 and 14 mounted in longitudinally spaced apart relation on a frame 16. One of the rollers is power driven to cause the belt 10 to orbit, preferably continuously, and its horizontal top run 18 to move in the direction of the arrow. The transport belt 10 is made of any suitable flexible material. The belt may, for example, be made of woven, high temperature resistant material such as Kevlar® or a glass fiber reinforced resinous plastic material and is coated on its outer surface with a suitable release agent or material, preferably polytetrafluoroethylene (TFE) or fluorinated ethylenepropylene (FEP) marketed under the trademark Teflon®. This release coating 20 (FIGS. 2 and 3) provides the belt with a nonporous surface capable of releasing plasticized adhesive which has adhered thereto, after cooling, as will become more apparent hereinafter.
There is a misting station 22 (FIG. 2) near the left end of the transport belt as viewed in FIG. 1. At this station, a water pipe 24 above the top run 18 of the transport belt extends across the full width of the belt and has spaced spray nozzles 26 on the underside which spray a predetermined volume of a fine mist of water on the top surface of the belt. The mist may be applied to the belt in varying amounts, for example, one to eight grams per square foot. The water may be taken from a standard municipal water supply line. Condensed steam vapor may also be used. The temperature of the water and of the transport belt will be maintained substantially below 212° F. at the misting station to prevent vaporation and loss of water to the atmosphere. The moisture from nozzles 26 applied to belt 10 prevents "bounce" and migration of powdered adhesive granules deposited on the belt at the next station and assists in the plasticizing of the deposited adhesive.
The top run 18 of the wetted transport belt 10 moves from the misting station 22 to the next station 30 (FIG. 3) where adhesive is applied uniformly to the top surface thereof. At station 30, powdered granules of adhesive 32 in hopper 34 are metered out of the hopper preferably onto a grooved or wire covered roll 36 and fall by gravity onto the top surface of the upper run of the transport belt 10. As shown in FIG. 3, the hopper 34 and roll 36 are parts of a dispensing unit 40 mounted in spaced relation above the transport belt 10. Other methods of dispensing the adhesive powder can be employed. The adhesive is preferably dispensed in discrete particle form in a uniform pattern over the surface of the belt in a width as required depending on the width of the material to be coated and preferably in a range of 0.5 to 60 grams per square meter, as desired. The amount of adhesive applied should be no more than needed so that there will be only minimum penetration of adhesive below the surface of the panels.
The adhesive employed in this process is preferably thermoplastic and one which will reactivate. It is preferably, but not limited to, a polyamide adhesive which will activate at about 212° F. or above. Polyesters, EVA and other thermoplastic adhesives in powder form may also be used. Excellent results may be achieved with a thermoplastic polyamide adhesive No. H005 in powder form produced by Elf-Atochem Co. which has a particle size of 0-600 microns and preferably 200-500 microns. This adhesive plastictzes at about 240° F. to 260° F. with dry heat and about 212° F. to 215° F. with vapor, that is, it becomes sufficiently tacky at those temperatures to adhere to the surface of the transport belt 10.
The next station to the right of station 30, is the preheating station 42. A conductive heater 44 is positioned beneath the upper run of the transport belt 10 and a radiant heater 46 is positioned above the upper run. Other heat supplying means may be employed, if desired. These heaters raise the temperature of the belt 10, and the moisture and adhesive thereon, to a temperature high enough to make the adhesive tacky and cause it to adhere to the belt. The adhesive is "tacked" to the belt in a uniform, non-continuous pattern in which the particles of adhesive powder remain discrete or separated and do not form a continuous film. Using the No. H005 adhesive referred to above, the temperature is raised to about 212° F. which with vapor is the tackifying temperature of the adhesive.
The transport belt 10 moves from the preheating station 42 to the loading station 50 where cut layers or panels 51 of material to be processed are positioned upon the adhesive coated top surface of the upper run of the transport belt 10. The material to be processed is porous and preferably of a fibrous material or of an open or closed cell foam material. Suitable foamed plastic materials may be made of polystyrene, urethane, polypropylene or latex. A suitable fibrous material may, for example, consist of a mix of cellulosic fibers of wood, fiberglass mat or the like and other fibers which may be thermoplastic in nature and selected from the vinyl or polyester or polyolefin families, bonded together by a suitable bonding agent. The panels 51 are preferably self-supporting and semi-rigid although somewhat flexible.
The panels 51 which have been placed on the transport belt at station 50, are advanced to a heating station 60 (FIG. 5). As shown, a second transport belt 62 may be provided to assist in advancing the panels. Belt 62 may be made of the same material as belt 10. No release agent on the outer surface of the belt 62 is needed because the adhesive will not penetrate far enough into the panels to reach the belt 62. This second transport belt 62 is positioned above the first transport belt 10 and extends over a pair of parallel, horizontal rollers 70 and 72 mounted in longitudinally spaced apart relation on the frame. The rollers 70 and 72 are parallel to the rollers 12 and 14 which support the first belt 10 and are positioned above the first belt 10 so that the bottom run of the second belt is disposed in spaced relation above and parallel to the top run of belt 10 and contacts panels on the belt 10. Thus the panels are sandwiched in a space of predetermined height between the two belts. The panel thickness is maintained by the two belts. The panels are advanced by the two belts and pressed down on the adhesive coating on belt 10. One of the rollers 70, 72 is power driven causing the second belt to orbit at the same speed as the first belt so that the two belts together advance the panels through and beyond the heating station.
At the heating station 60, there are heating segments 76 above the lower run of the top belt 62 and heating segments 78 beneath the upper run of the bottom belt 10 to apply heat to the belt, to the adhesive and to the panels being transported. The lower heating segments 78 are normally fixed and the upper heating segments 76 are mounted on a platen 81 and are adjustable vertically by any suitable means such as the air cylinder 80 to provide a preset space between the upper and lower heating elements and a predetermined amount of pressure on the transport belts and panels. The platen 81 is connected to the air cylinder 80 by a frame 81' which clears the upper run of the top belt 62. Separate air cylinders may be provided for the individual heating elements 76, if desired. If a 10 mm foam is to be coated with adhesive, a preset space of 9 mm could be provided between the belts which would impress the foam 1 mm. The temperature of the heating segments is also adjustable to provide the correct viscosity and temperature of adhesive required of the material to be coated. By controlling the temperature of the adhesive and the material, the adhesive can be effectively prevented from penetrating beneath the surface of the material, or the amount of adhesive actually penetrating can be minimized. In this heating station beyond the heating segments, pressure rollers 82 and 83 may also be used to provide additional pressure on the belts and on the panels passing between the belts which may be required for dense or tightly woven panel materials. The pressure roller 82 in this instance is on a fixed axis, and pressure roller 83 is vertically adjustable by an air cylinder 84. Roller 83 is connected to air cylinder 84 by a frame 87 which clears the lower run of bottom belt 10.
In the heating station, the adhesive coating on the belt is heated to an activating temperature which is somewhat above the minimum tackifying temperature of the preheating station 42 in order to cause the adhesive particles to soften sufficiently and become viscous enough to flatten and elongate to span or bridge the cell structure of the foam or space between the fibers. The surfaces of the panels are thus coated but not enough adhesive is used to allow more than minimal penetration of the adhesive into the body of the fibrous or cell structure of the material or minimal reduction in porosity of the material. The fact that the adhesive is merely transferred from the belt to the panels of material also reduces to a minimum penetration into the body of the panels. Using the H005 adhesive referred to above, the temperature of the adhesive and panels in the heating station may be raised to a temperature on the order of about 240° F. to 260° F. Obviously the temperature will vary depending upon the materials and adhesives used.
The panels are moved by the conveyor belts 10 and 62 beyond the heating station to a cooling station where cooling segments 90 above the lower run of the upper belt 62 and beneath the upper run of the lower belt 10 are vertically adjustable by air cylinders 92 to provide a predetermined amount of space and compression on these belts and hence on the panels being processed. The cooling elements 90 are connected to the air cylinders 92 by frames 93 which clear the transport belts. The cooling segments cool the belts, adhesive and panels to a temperature below the initial plasticizing temperature of the adhesive, in this instance substantially below 212° F., causing the adhesive to resolidify and to release from the Teflon® coated surface of the belt 10 on which it is supported and remain adhered to the material. The belt 10 advances the panels beyond the cooling station to the unloading station 93 where they may be removed either by hand or by a suitable workhandling device.
The panels after processing have a solidified adhesive coating on one surface which, when reheated to an activating temperature, can be adhered to another panel or to a decorative trim cover layer, for example. As stated above, automotive trim panels such as headliners can be made by using the adhesive coated panel of this invention as a shell or substrate and laminating a decorative cover to the adhesive coated side of the panel.
The process of this invention is not limited to a particular cell structure or density of foam, type or composition of textile fibers and/or micron size of the adhesive powder.
FIG. 5A is an enlarged photographic view of foam material to which powdered adhesive has been applied by the process of this invention. The adhesive used in this photograph initially had a particle size in the range of 100 to 500 microns. It will be noted that the adhesive (light colored areas) remains on the surface of the foam, does not appreciably enter the cell structure of the foam, and will provide a quality product to which a second panel or sheet may be adhered in a subsequent laminating process. The adhesive was applied in the amount of approximately 30 grams per square meter.
FIG. 5B is an enlarged photograph in which the same adhesive powder was applied in the same amount by the process of this invention to a panel made of fibrous material. Again, it will be observed that the adhesive (light colored areas) remains essentially on the surface of the fibrous material to provide good lamination characteristics.
FIG. 6A is an enlarged view of the same foam material of FIG. 5A in which the same adhesive was sprinkled upon the top surface of the material and conveyed below a radiant heater in accordance with a prior art method. It can be observed that a major portion of the adhesive (ball or egg shaped) has fallen into the cell structure of the foam and is no longer available on the surface to provide a quality lamination. FIG. 6B is similar to FIG. 6B but in which the adhesive is applied to fibrous material by the same prior art method of simply sprinkling on the top surface and heating. It will be seen that a major portion of the adhesive (ball or egg shaped) has fallen into the fibrous structure of the mat rather than remaining on the surface. | A method of coating the surface of semi-rigid porous materials such as open cell foam or fibrous compositions with a thermoplastic adhesive in powder form which will reactivate. The powdered adhesive in a size range of 0-600 microns will remain on the surface of such materials even when cell diameter of the foam or space between fibers is larger than adhesive particle size. High porosity is maintained in the coated product. First a thermoplastic adhesive in powder form is dispensed uniformly onto the surface of a carrier belt which is coated with a release agent and is moving continuously. The adhesive advances to a preheating station where the adhesive is plasticized and will adhere to the carrier belt to prevent movement, after which the foam or fibrous material is placed on the adhesive which is adhered to the belt. The adhesive and material advance to a second heating station where the adhesive is fully melted to allow the adhesive to bridge cells in the foam or space between fibers. The material and adhesive then advance to and through a cooling station where temperature of the adhesive and material are reduced to allow the adhesive to resolidify and the composite to release from the carrier belt and exit the machine. | 3 |
RELATED APPLICATION
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/036,670 filed Mar. 14, 2008, the entirety of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a vehicle knuckle that is adapted to cooperate with a fluid driven motor. More particularly, the present invention relates to a steerable vehicle knuckle with an inventive fluid supply, return and drain lines and other fluid paths for communicating fluid to and from a fluid driven motor.
BACKGROUND OF THE INVENTION
Those skilled in the art know that some vehicles, such as trucks, farm vehicles, and heavy duty construction vehicles, have wheels that are driven by hydraulic drive motors located at the wheels. Typically, each wheel end has a knuckle that utilizes a plurality of large hydraulic fittings that function as supply, return and drain ports. The ports are typically located all about the knuckle. Hoses, which are connected to these fittings at these locations, are required to traverse a large arc when the axle is steered. Such an arrangement of fittings and hoses, however, is difficult to package within the vehicle and uses large amounts of hose material.
A few examples of methods of providing fluid to a hydraulically driven wheel include devices described in the following patents. U.S. Pat. No. 4,171,732 discloses a fluid supply port on an upper surface of an inboard portion of a knuckle. The fluid return port, however, is located on a lower surface of the inboard portion. This design causes significant problems in packaging the hoses attached to these ports. Additionally, the fluid return hose, being located below the spindle, is highly susceptible to damage from items on the ground and from the ground itself.
U.S. Pat. No. 3,612,204 teaches a rigid fluid supply and return lines fixedly attached to an upper portion of a boss. The motor may pivot about the boss to provide steering to a wheel. As can be appreciated by FIG. 7 of this patent, the fixed fluid lines take up a tremendous amount of space at the wheel end.
U.S. Pat. No. 4,111,618 discloses supply and return lines all entering the spindle substantially parallel with the spindle centerline. The supply lines are located above/below the drain line, the drain line is at the centerline. All fluid lines are arranged about the centerline of the spindle and enter the spindle at this point as well.
As can be appreciated from the above discussion, some designs require a large amount of hose material and require that the fluid hoses traverse a large arc when the axle steers, which is difficult to package. Thus, a vehicle having hydraulic hoses connected to a wheel end having a hydraulic motor disposed thereon, may benefit from an arrangement of hydraulic hoses that does not require a large amount of hose material and does not require a wide arc for the hoses to traverse when the wheel end is steered in various directions. Such an arrangement would be less expensive to produce, easier to package, more robust, allow for faster steering reaction, and would be more easily connectable at the time of assembly of the vehicle.
SUMMARY OF THE INVENTION
A vehicle knuckle is disclosed that has an inboard portion that defines an upper arm and a lower arm. The knuckle also has an outboard portion that defines a spindle. The outboard portion is adapted to cooperate with a fluid driven motor. The arms define a cavity where an end portion of an axle is pivotally received. A connecting wall of the cavity connects an upper wall and a lower wall, also of the cavity, together. Fluid supply ports are located on an upper surface of the upper arm of the inboard portion adjacent the upper wall of the cavity for communicating fluid to the motor. Fluid drain lines are oriented substantially parallel one another near a centerline of the knuckle for draining fluid from the motor. The drain lines extend from the outboard portion to ports located in the connecting wall of the cavity.
Further advantages of the present invention will be apparent from the following description and appended claims, reference being made to the accompanying drawings forming a part of a specification, wherein like reference characters designate corresponding parts of several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a three dimensional cut away view of a vehicle hydraulic assist wheel end in accordance with the present invention;
FIG. 2 is a partial cross-sectional view of an alternate embodiment of a vehicle hydraulic assist wheel end in accordance with the present invention; and
FIG. 3 is a partial cross-sectional view of a second alternate embodiment of a vehicle hydraulic assist wheel end in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
It is to be understood that the present invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless the claims expressly state otherwise.
Illustrated in FIG. 1 is a hydraulic assist wheel end 10 that comprises a motor 11 , a wheel drum 12 , and a steerable knuckle 13 . A hub 36 is rotatably mounted radially outboard to the knuckle 13 . The hub 36 is drivingly connected to the motor 11 so that when the motor 11 is energized, it causes the hub 36 to rotate. The motor 11 may be such as those produced by Poclain Hydraulics Industrie of France.
The hub 36 has a bolt flange 38 with a plurality of bolt apertures 40 . The wheel drum 12 is located radially outward from the hub 36 . The drum 12 has a bolt flange 42 that abuts the bolt flange 38 of the hub 36 . The drum bolt flange 42 has a plurality of apertures 44 that align with the apertures in the hub bolt flange apertures 46 . Bolts 14 are located through the hub bolt flange apertures 46 and the drum bolt flange apertures 44 to fixedly connect the hub 36 and the wheel drum 12 .
The hub 36 and the drum 12 rotate about the centerline C of the knuckle 13 by way of bearings 17 A, 17 B which are located between the knuckle 13 and the hub 36 .
The knuckle 13 has an inboard portion 18 that defines an upper arm 19 and a lower arm 20 . A kingpin 15 , which is located between the upper arm 19 and the lower arm 20 pivotably connects an end portion of an axle 16 of a vehicle (not shown) to the knuckle inboard portion 18 , permits the vehicle to be steered about a centerline D of the kingpin 15 . The knuckle 13 also has an outboard portion 21 that defines a spindle 22 . The outboard portion 21 is adapted to cooperate with the fluid driven motor 11 . Preferably, the motor 11 has a circular recess 48 for receiving the outboard portion 21 of the cylindrical spindle 22 .
The arms 19 , 20 define a cavity 23 where the end portion of the axle 16 is pivotally received. A knuckle connecting wall 24 connects a knuckle upper wall 25 and a knuckle lower wall 26 together.
A first fluid pressure supply port 27 and a second fluid pressure supply port 28 are located on an upper surface 29 of the upper arm 19 of the knuckle inboard portion 18 radially outward from the upper wall 25 of the knuckle 13 for communicating fluid to the motor 11 . Fluid flowing through the first pressure supply port 27 , via pressure supply line A (hidden), rotates the motor 11 in a first direction, thus causing the wheel drum 12 to move, for example, in a forward direction.
Alternatively, fluid may be communicated to the motor 11 through pressure supply line B via second pressure supply port 28 . In this case, the motor 11 would rotate in a second direction, opposite the first direction, thus causing the wheel assembly to move, for example, in a rearward direction.
Two fluid return drain lines 30 , 31 are oriented substantially parallel one another near the centerline C of the knuckle 13 for draining fluid from the motor 11 . The lines 30 , 31 extend from the outboard portion 21 to ports 32 , 33 located in the connecting wall 24 of the knuckle 13 . Line 30 is shown draining hydraulic fluid from the motor 11 and a portion of the knuckle 13 , while line 31 is shown draining hydraulic fluid from another portion of the knuckle 13 . Although not shown in the particular cut away of FIG. 1 , line 31 is also in direct fluid communication with the motor 11 itself. The lines 30 , 31 may be connected to a sump system (not shown).
A first internal drain port 34 is preferably located between the inner bearing 17 A and the outer bearing 17 B. The internal drain port 34 is substantially oriented perpendicularly to the return drain line 31 . The internal drain port 34 can be utilized to drain fluid to the return drain line 31 .
A second internal drain port 35 is located outboard of the outer bearing 17 B. The internal drain port 35 is substantially oriented perpendicularly to the return drain line 30 . The internal drain port 35 can be utilized to drain fluid to the return drain line 30 .
As a result of locating the fluid pressure supply ports 27 , 28 on the upper surface 29 of the upper arm 19 , close to the periphery of the kingpin 15 about the kingpin steer axis centerline D, the supply ports 27 , 28 would be connected to supply hoses that are shown as hidden lines in FIG. 1 . Here, the supply hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin 15 .
Also, as a result of disposing the drain lines 30 , 31 parallel to the centerline C of the knuckle 13 , the drain ports 32 , 33 would be connected to drain hoses that are shown as hidden lines in FIG. 1 . Here, the drain hoses are formed in a small travel arc that follows closely the circular curvature of the kingpin 15 .
Thus, the supply and drain hoses would effectively allow the hydraulic assist wheel end 10 to pivot about the kingpin steer axis centerline D when the vehicle is being steered.
By reducing the travel arc for these hoses, the space (area) taken up by the hoses is greatly reduced. It can be appreciated that since the hoses do not travel through a large arc when the spindle is turned, that less hose material can be used. Thus, less drain hose material is required to accomplish the same function as the prior art designs. Additionally, by locating both of the supply hoses together on an upper surface 29 of the upper arm 19 of the knuckle 13 , the hoses are prevented from coming in contact with the ground or obstacles on, propelled from, or protruding from the ground that may damage the hoses. Also, the pressure supply ports 27 , 28 are at least prevented from being damaged in the same ways.
FIG. 2 illustrates an alternate embodiment vehicle hydraulic assist wheel end 10 ′ with the motor 11 , the wheel drum 12 , the knuckle 13 , the hub 36 , and the inner bearing 17 A and the outer bearing 17 B.
The fluid pressure supply port 27 or 28 is also shown connected to its corresponding supply line A/B and located on the upper surface 29 .
Also shown is a first spacer 52 disposed between and abutting an outer race 60 of the inner bearing 17 A and also an outer race 62 of the outer bearing 17 B. The spacer 52 has an inner landing 54 and an outer landing 56 with an angled landing portion 58 therebetween.
An outboard portion 70 of the outer landing 56 is also in contact with an inwardly extending portion 72 of the hub 36 . The outer race 62 of the outer bearing 17 B is seated within the inwardly extending portion 72 of the hub 36 .
An inboard portion of 74 of the inner landing 54 is also in contact with an inwardly extending portion 76 of the hub 36 . The outer race 60 of the inner bearing 17 A is seated within the inwardly extending portion 74 of the hub 36 .
The inner landing 54 has a greater outer diameter than an outer diameter of the outer landing 56 . Thus, the function of the angled landing portion 58 is to connect the landings 54 , 56 .
The spacer also comprises an inwardly disposed surface 68 that extends radially inward from the land 56 . The inside diameter surface 68 extends radially inwardly in close proximity clearance to the spindle 22 outside diameter.
Spacers 52 of various sizes may be used, which at least permits the use of the same spindle 12 and motor 11 while adapting to wheel assemblies of varying sizes. The vehicle hydraulic assist wheel end 10 of FIG. 1 has no spacer disposed between and abutting the races 60 , 62 . Preferably, the spacer 52 is unitary and one piece.
FIG. 3 illustrates a second alternate embodiment vehicle hydraulic assist wheel end 10 ″ with the motor 11 , the wheel drum 12 , the knuckle 13 , the hub 36 , and the inner bearing 17 A and the outer bearing 17 B.
The fluid pressure supply port 27 or 28 is also shown connected to its corresponding supply line A/B and still located on the upper surface 29 .
A second spacer 64 is located radially outward from the outboard portion 21 of the knuckle 13 . The spacer 64 preferably has a flat outboard surface 78 in direct contact with an inner race 80 of the outboard bearing 17 B. A flat inboard surface 82 is in direct contact with an inner race 84 of the inboard bearing 17 A. A flat radially outermost surface 86 is in close proximity clearance 66 with an inwardly extending hub portion 88 . In all embodiments, the bearings 17 A, 17 B rotatingly support the hub 36 about the knuckle 13 . The second spacer 64 may be of a one piece, unitary construction.
Spacers 64 of various sizes may be used, which at least permits the use of the same spindle 12 and motor 11 while adapting to wheel assemblies of varying sizes. Preferably, the spacer 64 is of a unitary, one piece construction.
It is to be understood that the patent drawings are not intended to define precise proportions of the elements of the invention but that the patent drawings are intended to be utilized in conjunction with the rest of the specification. Unless expressly specified to the contrary, it should also be understood that the illustrated differences between various elements of the invention, which may be in fractions of a unit of measurement, are not intended to be utilized to precisely measure those differences between the various elements.
In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than specifically explained and illustrated without departing from its spirit or scope. | A steerable vehicle knuckle has an inboard portion defining upper and lower arms, with a kingpin between them, and has an outboard portion defining a spindle that cooperates with a fluid driven motor. The arms define a cavity where an axle end portion is pivotally received. Fluid supply ports, which supply fluid to energize the motor, are located on an upper surface of the knuckle's inboard portion. Fluid drain lines extend within the knuckle from the motor to the cavity and are utilized to drain fluid from the motor. The supply ports and drain lines are each connected to separate hoses formed in a small arc that follows closely the circular curvature of the kingpin. This arrangement of port, lines, and hoses is less expensive to produce, easier to package, more robust, allows for faster steering reaction, and is easier to assemble than conventional arrangements. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation application of parent application Ser. No. 970,819 filed Dec. 18, 1978, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a product accumulator for use with a conveyor belt or similar article handling device and is particularly intended for re-circulating items carried on a through-lane belt.
The accumulator of the present invention has particular application and use in connection with cans or similar cylindrical products, such as rolls of toilet paper and the like, but is also usable with bottles (such as soft drinks or beer) or non-circular products as will be hereinafter described.
Article flow-control device unscrambling apparatus, and accumulators per se for conveyor belts are not new, and attention is directed to U.S. Patents Vickery U.S. Pat. No. 2,003,097, Osborne U.S. Pat. No. 3,104,753, Reading U.S. Pat. No. 3,342,012, Fink U.S. Pat. No. 3,604,551, and Brutcher U.S. Pat. No. 4,037,710.
It is evident that others have tried to provide an accumulator or storage space in connection with a moving conveyor belt, wherein the products carried on the belt can be temporarily stored in the event that the take-off or out-feed portion of the conveyor belt is temporarily blocked or stopped, or if the products are, for some reason, prevented from moving along the conveyor line.
It is important that the accumulator operate in such a manner that as the products arrive at the in-feed end of the accumulator (when the out-feed end is jammed or for any reason the products do not flow along the conveyor) that they be moved or circulated so as to prevent a product "lock-up" which would prevent the products from moving along the conveyor at the out-feed end once the jam or stoppage is removed.
It is particularly advantageous that these accumulators be placed selectively along a conveyor belt, and that the conveyor system need not be modified substantially to adapt the placement of the accumulator therealong.
SUMMARY OF THE INVENTION
The accumulator of the present invention includes a table-like support (having a center lane or through-lane conveyor belt portion which can be aligned with an existing conveyor belt, or which may be placed in a position to straddle an existing conveyor belt) so that a central, through-lane belt is provided in the middle of the table. On either side of the center lane, a plurality of auxiliary belts are placed, all auxiliary belts on one side moving in one direction and all on the other side moving in the opposite direction. Suitable guides, one at each end of the through-lane belt guide the products or articles so that a circulatory motion is provided for the articles, so that the articles move from belt to belt and thus a lockup or jamming is prevented.
The accumulator of the present invention is relatively uncomplicated in design and construction, and operates on a rotary or circulatory principle which assures that the products will not be blocked in the accumulator and will always be available for discharge when the out-feed is open to carry products away.
Hence, a principle object of the present invention is to provide a rotary accumulator for temporarily storing products on both sides of a conveyor belt.
A further object of the present invention is to provide a non-blocking accumulator which can function with an existing conveyor system and which can be adjusted for handling objects of various sizes and various configurations and is not limited to handling products with a circular cross-section.
An additional object of the present invention is to provide a conveyor belt accumulator which does not require sophisticated guide rails, complicated guide vanes, or driven helper devices to insure the circulating of the product in the accumulator.
With the above and other objects in view, a better understanding of the present invention will be achieved by reference to the following detailed description.
DETAILED DESCRIPTION
For the purpose of illustrating the present invention, there is shown in the accompanying drawings a form thereof which is at present preferred, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized and that the invention is not limited to the precise arrangements and organizations of the instrumentalities as herein shown and described.
In the drawings, wherein like reference characters indicate like parts:
FIG. 1 is a perspective view of the accumulator of the present invention with arrows indicating the relative movement of the belts or traveling table-portions of the accumulator.
FIG. 2 is a top-plan view of the accumulator of FIG. 1 illustrating particularly the movement of the product along the central through-line belt when products are moving normally through the outfeed of the conveyor system.
FIG. 3 is a top-plan view, similar to FIG. 2, showing the motion of the products in the accumulator when the out-feed lane is blocked and products continue to arrive at the in-feed end of the accumulator.
FIG. 4 is a fragmentary top plan view of the out-feed end of the accumulator of the present invention, showing how the guide can be adjusted to accommodate non-circular products.
In FIG. 1, the accumulator 10 is seen to include a generally table-like portion 11 having a plurality of legs 12 which support an upper-working surface 13. The accumulator 10 may be constructed and arranged with a central slot-like portion 14, through which a through-line conveyor belt 15 passes. The conveyor belt 15 may be mounted in appropriate guides, such as the rollers 16, and driven by suitable means 17 from a motor or power sources 18. In this configuration, which is the preferred embodiment, the accumulator may be disposed so that the through-lane belt 15 is aligned with another conveyor belt (not shown) at the in-feed end 19, and another conveyor belt (not shown) aligned with the out-feed end 20 of the belt 15. Thus, objects which are conveyed from another belt to the in-feed end 19 of this accumulator will pass directly onto the belt 15 and be carried therealong through the accumulator and out the out-feed end 20 and onto another conveyor belt. This continues as long as the out-feed end 20 is not blocked by back-up of product or in any way closed so that the objects which arrive at the in-feed end 19 cannot pass out through the out-feed end 20.
At this point, it is seen that the accumulator, with its through-lane 15, acts merely as a continuation of another portion of a conveyor belt system.
In another embodiment, the through-lane belt 15 may be removed and the table 11 may be positioned beneath an existing belt (not shown) so that the accumulator 10 will operate with such existing belt in the manner described hereafter.
It is well understood in this art that there are times when the objects carried along the conveyor become jammed or when removal from the end of the conveyor is not done at a rate as fast as in the in-feed and, therefore, the products jam-up or accumulate along the conveyor belt. At this point the accumulator of the present invention acts to provide temporary storage or accumulator space until the discharge end is free of any occlusion and the objects are permitted to move outwardly through the discharge end 20.
This is accomplished in the following manner:
On the table-like surface 13, on one side of the through-lane 15, a plurality of belts or moving surfaces 21-a, 21-b and 21-c are disposed in such a manner as to provide a generally flat surface co-planar with the top of the through-lane conveyor belt 15. Each of these belts 21-a, b and c move in the same direction as shown in the arrows 22-a, b, and c in FIG. 2.
These belts 21-a, b, and c can be driven by suitable mechanism (not shown) within the housings 23 and 24. Such mechanism may be suitably connected to the motor 18 and drive mechanism for the through-lane belt 15, or may be independently driven by additional motors (not shown). The belts 21-a, b, and c may be driven at the same linear speed as the through-lane belt 15 or may bbe driven at selectively different speeds, depending upon the motor to be imparted to the objects accumulating on the table.
On the opposite side of the through-lane conveyor belt 15, additional belts 25-a, b, and c are disposed to create a further extension of the planar surface of the top of through-lane belt 15, and these belts 25-a, b, and c move in a direction opposite to the belts 21-a, b, and c as shown by the arrows 26-a, b, and c.
The belts 25-a, b, and c are driven by suitable mechanism (not shown) contained within the housing 27 and 28, either by the motor 18 or by independent power sources contained within the housings 27 and 28.
As is evident from the preceding description, any objects placed upon the belts 21-a, b, and c will be moved from the in-feed end of the accumulator toward the out-feed end thereof, whereas any objects disposed on the belts 25-a, b, and c will be moved from the discharge end toward the in-feed end of the accumulator. A planar horizontal accumulating area for objects is formed by the upper surfaces of the conveyors 15, 21a, 21b, 21c, 25a, 25b and 25c.
Suitably arranged on the top of the accumulator 10, near the down-stream or out-feed end of the belts 21-a, b, and c is an inclined bracket or guide 29. This bracket or guide has its angled portion 30 disposed above the belts 21-a, b, and c so that the belts may pass therebeneath and so that the angled portion 30 will move the objects toward the through-lane belt 15 and toward the out-feed 20, as is shown particularly in FIG. 3. A guide-portion 31 extends along the through-lane belt 15 and outwardly toward the out-feed end 20, from the bracket corner 32, and is suitably mounted adjacent the housing 24, so that this guide may be moved downstream toward the out-feed as is shown particularly in FIG. 1, or upstream toward the in-feed end, as is shown in FIG. 2, or even further upstream, as is shown in FIG. 4, to accommodate objects of different sizes and shapes.
On the opposite side of the table from the guide 29 is another guide 33 with an extension 34 supported by the housing 28 and longitudinally movable upstream or downstream to provide a matching or mating guide member for the guide 29 so as to insure the prevention of any lockup or jamming of the products guided along the arm 30 of the guide 29 toward the discharge opening between the extensions 31 and 34. The termination 32 of the angled guide 30, as shown in FIGS. 3 and 4, is spaced upstream from the output opening to prevent jamming.
A guide bracket 35, similar to the bracket 29, is disposed at the in-feed end of the table, and overlying the belts 25-a, b, and c. This guide has an extension 36 which may be mounted on the housing 27 for adjustment similar to the adjustment of the guide 29. Similarly, another bracket 37, similar to the bracket 33, with an extension 38, is mounted on the housing 23 to provide a co-relative adjustment with the guide 35 to prevent jamming of the products at the in-feed end of the accumulator. Such products are moved toward that end by the belts 25-a, b, and c. The termination point 50 of the angled guide 35, as shown in FIG. 3, is spaced downstream from the input opening for products entering the accumulating area to prevent jamming.
As can be clearly seen in the FIG. 2 illustration, as long as the products can move freely along the through-lane conveyor 15, through the accumulator from the in-feed end to the out-feed end thereof, the products will stay on the through-lane belt 15 and move directly through the accumulator without passing onto any of the belts 21-a, b, and c or 25-a, b, and c.
However, when the out-feed end becomes blocked because products cannot move along the through-lane conveyor 15 and out the out-feed end 20, the products will accumulate on the through-lane conveyor between the guides 31 and 34, as shown in FIG. 3, whereupon additional products brought in by the through-lane conveyor 15 will be guided from belt 15 onto the auxiliary belt 25-a. At this point, they may move toward the in-feed end on belt 25-a, or may be forced by additional incoming products onto the auxiliary belts 25-b or 25-c. In any event, the incoming products will be kept within the confines of the accumulating area or tabletop 13 of the accumulator, generally circulating back toward the in-feed end 19. When products have moved along the auxiliary belts 25-a, b, and c to strike the guide 35, they will be urged toward the through-lane conveyor 15 whereupon they will strike the incoming products, forcing them onto the auxiliary belts 21-a, b, or c depending upon the quantity of products accumulated. Additional incoming products will move into this circulatory pattern, which is illustrated in FIG. 3, and the products kept within the accumulator will continue to circulate until the out-feed end of the accumulator is unblocked, or the products are free from any jamming, and start to move outwardly along through-lane conveyor belt 15 to the out-feed 20. Thereafter, any product on the through-lane conveyor 15 will move directly outward and, as the belts 22-a, b, c and 25-a, b, and c continue to feed the products on to the through-lane conveyor 15, under the impetus of the guides 29 and 35, sooner or later all of the products accumulated on the table-top 13 will be carried outwardly through the out-feed 20 by the through-lane conveyor belt 15.
As is illustrated particularly in FIG. 4, the guides 29 and 33 may be adjusted by sliding the extensions 31 and 34 relatively along the length of the through-lane conveyor 15 so that the corner 32 between the portions 30 and 31 of the guide 29 may be located appropriately with regard to the guide 33 so as to accommodate non-circular products. As is seen in FIG. 4, the rectangular products 39 will normally pass outwardly along the out-feed end 20, but if a stoppage occurs, then a product 40, which is not contained between the extensions 31 and 34 is moved by the products 41 onto the belt 25-a.
As shown in FIGS. 2 and 3, the products exiting single file from the accumulating area at the output thereof are centered on an output line which is parallel to the conveyor 15 and is offset from an input line defined by the centers of products entering single file into the accumulating area at the input thereof. The angled guide 30 at its termination point 32 partially extends into the path of the products being advanced by the conveyor 15 along the input line from the input. Thus products are engaged and moved toward one side upstream from the output to prevent lockup of a line of products which could occur for some products if they extended in the same straight line from input to output of the accumulating area.
The width of the belts and the material of which they are made, as well as the surface pattern or configuration of the belts, can be adapted for the product to be handled on the conveyor. Thus, one may choose smooth belts for some products, and belts with rough surfaces for other products. The belts may be either cloth, rubber, or chain-link, depending upon the type of products to be accommodated, but in any event the upper surfaces of the belts provide a generally planar upper surface for the accumulator so that the products may be easily moved from belt-to-belt and from end-to-end and may slide sideways on the belts as they are moved by the guide, all without any damage to the product or jamming of the product between belts, and all with the intention of insuring that the relatively fluid-like circulatory motion continues on the accumulator as long as the discharge end of the through-lane 15 is stopped-up with product.
It is to be understood that the present invention may be embodied in other specific forms without departing from the spirit of special attributes hereof, and it is, therefore, desired that the present embodiments be considered in all respects as illustrative, and therefore not restrictive, reference being made to the appended Claims rather than to the foregoing description to indicate the scope of the invention. | A product accumulator for a conveyor system includes a movable through-lane belt having an in-feed end and an out-feed end, at least one first auxiliary belt disposed adjacent the through-lane belt and movable in the same direction, and at least one second auxiliary belt disposed adjacent the through-lane belt and movable in the opposite direction, adjustable stationary guides, one guide disposed adjacent one end of the first auxiliary belt near the out-feed end of the through-lane belt to guide product from the first auxiliary belt onto the through-lane belt, and another guide disposed adjacent one end of the second auxiliary belt near the in-feed end of the through-lane belt, to guide product from the second auxiliary belt onto the through-lane belt, said guides disposed closely above the belts and arranged to move product from belt to belt whenever product is prevented from moving along the out-feed end of the through-lane belt. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming apparatus which uses fuzzy inference, such as an electronic photography copier, and an electronic photography laser printer, which uses electrostatic images.
2. Related Background Art
It is well known that to obtain a high-quality image, desired potential must be supplied to a light-sensitive body (an image bearing member) in a charging process and a development bias must be set appropriately in a development process. Since a desired potential and a development bias differ depending upon room temperature, humidity, original density, the accumulated number of copied sheets or the like, these conditions must be considered at all times when the set values of a potential and a development bias are determined. Several examples about the relation between these conditions (state quantities), and a potential and a development bias (control quantities) will be described next.
When humidity is high, the surface of a light-sensitive body and a supporting member supporting it are moistened and a surface resistance value decreases. As a result, when electric charges are supplied to a light-sensitive body by a charging apparatus, some of the charges escape from the light-sensitive body and a desired potential cannot be obtained. For this reason, output from a charging apparatus must be increased under a high humiditY environment.
The fact that the density of a copy image varies with the density of the original is known. When high-density originals are copied in succession, the density of a copy image becomes high and a development agent is deposited on a white ground section, or, when low-density originals are copied in succession, the density of a copy image becomes low. Therefore, when the density of an original is high, a dark potential (potential after charging) must be set low or a development bias must be set high. When the density of an original is low, a dark potential must be set high, or a development bias must be set low.
In addition, when the number of copies is increased, the electrical capacity of a light-sensitive body increases as a result of the thickness of the light-sensitive layer becoming thinner and a required dark potential cannot be obtained. This results from the fact that the surface of a light-sensitive body is scratched, since after a visual image is transferred onto a transfer material (image bearing member), it passes through a process in which a remaining development agent on the light-sensitive body is scraped off with a brush or an elastic member (process of cleaning a light-sensitive body). Taking this factor into account, the output from a charging apparatus must be increased as the number of copies is increased.
As for the relation between various kinds of state quantities and control quantities mentioned above, the variations in all the state quantities cannot be corrected by using a single set value under the present situation. Hence, the output level in response to work is switched or output linked with a sensor is automatically set. Or, in some cases, no action is taken.
The switching of an output value in response to work entails much labor and the difficulty of judging switching timing. In particular, when judging switching timing, an appropriate output value must be found in which a number of conditions are considered simultaneously and decision criterion is entrusted to past experience based on much experimental data. A person who is not well informed about these criteria will have difficulty in judging switching timing. Also, if it is desired to set the output level to a more desired value, a plurality of output levels need to be held in memory and therefore the apparatus becomes expensive.
In addition, to set output automatically, a complex output control program must be prepared on the basis of a low of experimental data. As mentioned above, it is necessary to find an appropriate output value experimentally for a case where each of the conditions varies. A vast experimental data table is required before a program can be written and a lot of time and labor are needed. Actually, in many cases, many conditions cannot be taken into account and only those conditions which are particularly important are considered. In order to meet the need in recent years to improve the reliability of this kind of image forming apparatus, output control automation rather than the output value switching method, and a method of preparing a simple control program capable of easily taking in many conditions have been desired.
In a image forming apparatus, for example, a post charger (for supplying a uniform corona to a light-sensitive body before transferring to increase transfer efficiency), a transfer charging apparatus, and separation charger of an electronic photography copier include an apparatus that supplies charges to a toner image on a light-sensitive body from the outside, transfers the toner image onto a transfer material, and separates the transfer material from the light-sensitive body.
In particular, in a high-speed apparatus with a process speed exceeding about 400 mm/sec, regarding the charging quantity of each charger, factors such as the characteristics of a toner on a light-sensitive body, i.e., the quantity of charges of a toner (dependent on the state of an original), kinds of transfer materials, the state under which a transfer material is moistened, the transfer speed of a main body, the history state, such as the dirtiness of each charger, and so on are considered, and the set value of each charger output is obtained through repetition of complex experiments. However, generally, the deviation of the above-mentioned factors cannot be corrected using a single set value, so the switching of an output level in response to work and the automatic setting of output linked with a humidity sensor or the like are performed.
However, the switching of output level in response to work entails much labor and the difficulty of judging switching timing. Also, it is necessary to hold each of the plurality of the output levels from the charger in memory and the apparatus is expensive. Further, where output is automatically switched using a humidity sensor, an expensive humidity sensor is needed and the detected humidity sometimes does not correspond to the actual moisture content of a toner and a transfer material.
Generally, since the change in the atmospheric humidity acts on a toner and a transfer material with a certain time lag, accurate humidity detection is of no use. To use a humidity sensor effectively, a number of experiments and a complex, high-voltage control program are needed.
SUMMARY OF THE INVENTION
An object of the present invention is to enable a control of a process means for use in formation of images and for acting on the image bearing characteristics in an image forming apparatus which uses electrostatic images, as mentioned above, to be performed with high accuracy.
Another object of the present invention is to provide a control of the above-mentioned process means which is most appropriate after the existing circumstances are considered.
Still another object of the present invention is to realize a control of the above process means which provides a high-quality image.
The present invention which achieves the above objects is an apparatus for forming images using electrostatic latent images. The apparatus comprises a state quantity detection means for detecting a state which would affect the formation of an image as a quantity, a control quantity control means for controlling the operation of a charger, a developer, and a process means for an optical system or the like that acts on an image bearing member such as an electronic photography light-sensitive body, a transfer material or the like to form an image, a rule storage means for relating the relation between the above state to be detected and the control quantity by the control means as a certain rule and storing it, and an inference means for inferring the control quantity to be determined from a set of state quantities. The apparatus determines an action quantity for the image bearing member of the process means on the basis of the calculated results of the inference means.
These and other objects, features and advantages of the present invention will become clear when reference is made to the following description of the preferred embodiments of the present invention, together with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a control block diagram of a charging apparatus;
FIG. 2 is a schematic view illustrating the entire image forming apparatus;
FIG. 3 is a schematic view of a charge high-voltage unit;
FIGS. 4A, 4B, and 4C are graphs showing input and output membership functions in a first embodiment;
FIG. 5 is an explanatory view explaining the fuzzy rule of the first embodiment;
FIG. 6 is an explanatory view explaining the method of inferring a charge high-voltage set value;
FIG. 7 is a high-voltage setting flowchart;
FIGS. 8A and 8B are graphs showing the input and output membership functions (a portion) of a second embodiment;
FIG. 9 is an explanatory view explaining a fuzzy rule of the second embodiment;
FIG. 10 is an explanatory view explaining a method of inferring a bias set value;
FIG. 11 is a graph showing an output membership function of a third embodiment;
FIG. 12 is an explanatory view explaining a fuzzy rule of the third embodiment;
FIG. 13 is a graph showing an output membership function of a fourth embodiment;
FIG. 14 is an explanatory view explaining a fuzzy rule of the fourth embodiment;
FIG. 15 is a block diagram illustrating the configuration of the embodiment of the present invention;
FIG. 16 is a block diagram illustrating a control apparatus in one ,embodiment of the present invention;
FIG. 17 is a flowchart illustrating a control procedure by a CPU 801;
FIG. 18 is a flowchart illustrating a control procedure in step S2;
FIGS. 19A to 19E are views illustrating one example of a membership function; and
FIG. 20 is an explanatory view explaining the procedure of inference.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be explained in detail hereinunder with reference to the accompanying drawings.
FIG. 1 is a basic block diagram of a image forming apparatus of the present invention. Shown in the figure are a CPU 801 to be described later for performing fuzzy inference, a ROM 803 to be described later in which fuzzy rules and membership functions are stored, a RAM 805 to be described later used for a work area when fuzzy inference is performed, an A/D converter 813 for converting a digital signal to an analog signal, a D/A converter 814 for converting an analog signal to a digital signal, a surface potential sensor 180 for measuring the surface potential of a light-sensitive drum 131 (FIG. 2), a humidity sensor 181 for measuring humidity, a counter 182 for storing the accumulated number of copied sheets, a charge high voltage 183, the high-voltage output value of which is controlled by an instruction from the CPU 801. A room temperature sensor may be provided for detection for measuring temperature in place of the above humidity sensor.
FIG. 2 shows the internal configuration of a image forming apparatus in one embodiment of the present invention. Shown in FIG. 2 are a main body 100 having an image reading function and an image recording function, a pedestal 200 having a double-side process function to reverse a recording medium (sheet) at both-side recording and a multi-recording function to perform a plurality of recording on the same recording medium, a recirculating original supply apparatus 300 (hereinafter referred to as "RDF") for supplying originals automatically, and a staple sorter 400. Each of these apparatuses 200 to 400 can be used in combination at will.
In the main body 100, also shown in FIG. 2 are an original glass stand on which an original is placed, an illumination lamp 103 (light exposure lamp) for illuminating an original, scanning reflection mirrors 105, 107 and 109 (scanning mirror) for changing the light path of the reflected light of the original, a lens 111 having a focusing function and a varying magnification function, a fourth reflection mirror 113 (scanning mirror) for changing the light path, an optical system motor 115 for driving the optical system, sensors 117, 119 and 121, a light-sensitive drum 131, a main motor 133 for driving the light-sensitive drum 131, a charger 135 (hereinafter referred to as a "high-voltage unit"), a blank exposure unit 137, a developer 139, a transfer charger 141, a separation charger 143, a cleaning device 145, an upper-step cassette 151, an lower-step cassette 153, a manual paper insert slot 171, paper supply rollers 155 and 157, a regist roller 159, a transfer belt 161 for transferring paper on which an image is recorded to the fixation side, a fixer 163 for fixing transferred recording paper by thermal fixation, and a sensor 167 used at both-side recording.
The surface of the light-sensitive drum 131 consists of a photoconductor and a seamless light-sensitive body using a conductor. This drum 131 is axially supported and starts to rotate in the arrow direction in this figure by means of the main motor 133 which operates in response to the pressing of a copy start key to be described later. Next, an original placed on the original glass stand 101 is illuminated by the illumination lamp 103 integrally formed with the first scanning mirror 105, and the reflected light of the original forms an image on the drum 131 through the first scanning mirror 105, the second scanning mirror 107, the third scanning mirror 109, the lens 111 and the fourth scanning mirror 113.
The drum 131 is corona-charged by the high voltage unit 135. Then, an image (original picture image) illuminated by the illumination lamp 103 is exposed by a slit and an electrostatic latent image is formed by a known Carlson process.
Next, the electrostatic latent image on the light-sensitive drum 131 is developed by the development roller 140 of the developer 139, is made visible as a toner image. The toner image is transferred onto transfer paper by means of the transfer charger 141, as as described later. That is, transfer paper on the upper-step cassette 151 or the lower-step cassette 153, or transfer paper set on the manual paper insertion slot 171 is fed to the main-body apparatus by the paper supply roller 155 or 157, and the front end of the latent image and the front end of the transfer paper are registered. Thereafter, the transfer paper is ejected outside the main body 100 after it passes the section between the transfer charger 141 and the drum 131.
After transferring, the drum 131 continues to rotate and its surface is cleaned by the cleaning device 145 made up of a cleaning roller and an elastic blade.
FIRST EMBODIMENT
Next, the above-mentioned high voltage unit will be described.
FIG. 3 shows a known scortron type high voltage unit used in the present invention. Shown in the figure are a discharge wire 401, to which a high voltage is applied by a high-voltage power supply 404, a grid 402 to which a bias is applied by a bias power supply 405, and a grounded shield material 403. If the output from the power supply 404 is made larger, more current flows through the light-sensitive drum 131 and the charge potential of the light-sensitive body becomes high. Also, if the bias 405 is made higher, since a current flows through the light-sensitive drum until the potential matches the bias, the charge potential becomes high.
At this point, an example of the operation of the charge high-voltage control will be described. The following two state quantities are used as state quantities at high voltage control:
(i) Humidity
(ii) Original density.
As a control quantity, (iii) charge high voltage for the corona discharge device 135 is used.
FIG. 4 shows a fuzzy set called membership functions for the above state quantities and the control quantity of (i) to (iii). Humidity, original density, charge high voltage are broadly classified into several sets. For example, in the case of humidity,
(1) HL (Humidity Low)
Humidity is low.
(2) HL (Humidity Medium)
Humidity is medium.
(3) HH (Humidity High)
Humidity is high.
The degree belonging to each set is represented by a value from 0 to 1. An explanation will be given by taking as examples a membership function for humidity in FIG. 4A, a membership function for original density in FIG. 4B, a membership function for charge high voltage output in FIG. 4C, and HM (humidity middle) in FIG. 4C. The degree belonging to the set of HM when humidity is 55%, is 1.0, and the degree belonging to the set of HM when humidity is 48% or 62%, is 0.5. The same applies in other cases.
Next, a method of calculating charge high-voltage output from the state quantity of original density will be described.
To determine charge high-voltage output, for example, the following fuzzy rules are used.
(Rule 1)
If humidity =HL and original density =DL
then charge high-voltage output =PM.
(Rule 2)
If humidity =HH and original density =DL
then charge high-voltage output =PH.
In this way, a fuzzy rule is set as required. The fuzzy rule in this case is shown in FIG. 5.
FIG. 6 shows an example in which charge high-voltage output is calculated from the fuzzy rule using the above (Rule 1) and (Rule 2).
As an example, a case where humidity is denoted by x and original density is denoted by y will be considered.
In (Rule 1), the humidity is included in the set of HL at a degree of μx to the input x by the membership function for the humidity, and the original density is included in the set of DL at a degree of μy to the input y by the membership function for the original density. Thereafter, minimum values of μx and μy are taken and the values are assumed to be a degree that satisfies the conditions of rule 1. If the MIN operation of the values and the membership function for the charge high-voltage output is performed, the shape of the charge high-voltage output becomes a trapezoid shown in the shaded portion of S.
A similar calculation is performed in (Rule 2) and a trapezoid shown in the shaded portion of T appears. Thereafter, maximum values of the sets of S and T are taken, and a new set shown in the shaded portion of U is created. A value obtained from the calculation of the center of gravity of this set is set as a charge high-voltage output obtained by fuzzy inference. A similar step is performed on all fuzzy rules shown in FIG. 5.
Next, the flow of a fuzzy inference subroutine operation will be explained with reference to the flowchart of FIG. 7.
First, humidity and original density are measured using the humidity sensor 181 (installed inside an apparatus but its location is not particularly specified) and the surface electrometer 180 (9-1).
Thereafter, for all fuzzy rules in FIG. 5, by using the above-mentioned method and in accordance with each fuzzy rule, a degree belonging to the fuzzy set of control quantities is calculated from the degree in which state quantities belong to the fuzzy set (9-4) (9-5); a maximum value of the set belonging to each rule is calculated (9-6); the most highly probable control quantity is calculated by determining the center of gravity (9-7); and the center of gravity is set as a charge high voltage V to be determined (9-8).
The charge high voltage V is set at a value by units of 100 mV.
SECOND EMBODIMENT
Next, a second embodiment will be explained. In the second embodiment, as a state quantity, an accumulated number of copied sheets is included to take the degradation of the light-sensitive body into consideration in addition to the humidity and original density mentioned in the first embodiment. A potential control means is adapted to control a bias voltage to be applied to the grid in the scortron type charging apparatus mentioned in the first embodiment. That is, the state quantities are: (i) humidity, (ii) original density, and (iii) accumulated number of copied sheets. The control quantity is (IV) a grid bias voltage. The accumulated number of copied sheets is stored in a counter and the value can be read out as desired.
FIG. 8A shows the accumulated number of copied sheets ○3. FIG. 8B shows the membership functions of a bias voltage ○4. The membership function of state quantities of (i) humidity and (ii) original density is the same as in the first embodiment. Fuzzy rules for state quantities ○1 to ○3 and control quantity ○4 are as shown in FIG. 9.
Next, a description will be given regarding a method of calculating a bias voltage from the state quantities of ○1 to ○3. The method is the same as in the first embodiment. For example, the following fuzzy rules are used (See FIG. 9).
(Rule 1)
If humidity =HL and original density =DL and accumulated number of copied sheets =CL then bias =BM.
(Rule 2)
If humidity =HL and original density =DL and accumulated number of copied sheets =CM then bias =BH'.
A method of calculating a bias by fuzzy inference using the above (Rule 1) and (Rule 2) is shown in FIG. 10. The following are denoted: humidity =X, original density =Y, and accumulated number of copied sheets =Z. By performing fuzzy inference shown in FIG. 10 on each fuzzy rule shown in FIG. 9, the most highly probable control quantity is calculated from the calculation of the center of gravity and the center of gravity is defined to be the set value of a bias voltage.
THIRD EMBODIMENT
In the above-mentioned two embodiments, the control the dark potential of a light-sensitive body was described. However, the fuzzy control of a bright potential (white ground potential after exposure) and an intermediate potential (half-tone potential) in addition to the dark potential is possible. A bright potential is related to the fogging density of a white ground of an image. A fogging is a phenomenon that a toner is deposited on an area to be originally a white ground on an image. To reduce a fogging, a bright ground potential must be set at an appropriate value. It is experimentally known that a fogging increases when the potential difference between a bright potential V L and a development bias voltage V DC is either too small or too large. Further, it is known that a right value differs depending upon humidity and the accumulated number of copied sheets. The causes of these are not yet clarified, but, for example, the following can be inferred.
That is, some of the toner particles charged on a polarity opposite to a desired polarity on a development roller are deposited on a white ground by receiving an electrical force acting from the development roller to the bright potential section, causing a fogging. The larger the potential difference between V L and V DC is, the more the fogging increases because the toner particles receive a larger electrical force. Since, if humidity and the accumulated number of copied sheets vary, the charge quantity of toner particles whose polarity is reversed varies, it is supposed that the amount of fogging varies. The third embodiment intends to control V L so that a fogging is diminished at all times by fuzzy inference irrespective of humidity and the accumulated number of copied sheets. V L can be controlled using an amount of exposure which is controlled by a lighting voltage of the illumination lamp 103.
The state quantities in this embodiment are ○1 humidity and ○2 are accumulated number of copied sheets; a control quantity is ○3 a lighting voltage. The membership functions of ○1 and ○2 are the same as in the second embodiment and the method of detecting those quantities are as mentioned earlier. FIG. 11 shows a membership function of ○3. Fuzzy rules developed from experiments are summarized in FIG. 12. The method of actual fuzzy inference can be performed in the same way as in the first and second embodiments and therefore an explanation thereof is omitted.
FOURTH EMBODIMENT
Next, a description is given of a fourth embodiment in which a development bias voltage is controlled suitably at all times so as to stabilize original density (varies depending upon humidity and the accumulated number of copied sheets). This variation is thought to be due to the fact that the quantity of charges of toner particles, and the distribution state of the toner particles on the development roller, vary depending upon humidity and the accumulated number of copied sheets. That is, if humidity is high, a toner contains wafer and resistivity decreases, causing the charges of the toner to escape easily, and original density decreases. On the other hand, when humidity is low, toner particles having excessive charges stick to the development roller by a reflection force, and a phenomenon occurs such that development cannot be made. When the accumulated number of copied sheets increases, the amount of toner particles having excessive charges increases and it is supposed that developing efficiency decreases further. The state quantities in this embodiment are ○1 humidity and ○2 the accumulated number of copied sheets, and a control quantity is ○3 a development bias voltage. The membership functions of ○1 and ○2 are the same as in the second embodiment. The membership function of the development bias voltage ○3 is shown in FIG. 14. The fuzzy rules relating to it are shown in FIG. 15. The method of actual fuzzy inference can be performed in the same way as the first through the third embodiment, so an explanation thereof is omitted.
FIFTH EMBODIMENT
In the fifth embodiment, the operation of a corona discharge apparatus as a process means of the copier shown in FIG. 1 is controlled by fuzzy inference. As examples of a discharge apparatus, the transfer charger 141, the separation charger 143, and the post charger 142 are shown.
FIG. 16 shows the configuration (block diagram) of the fifth embodiment of the present invention. In FIG. 16, numeral 801 denotes a CPU which calculates, as a suitability calculation means, the suitability of a detected state quantity on the basis of the membership function for the state quantity stored in the ROM 803, obtains, as a calculation means, the inference results of each rule stored in the ROM 803 by a predetermined calculation on the basis of the calculated suitability, and infers, as an inferring means, a control amount on the basis of the inferred results of each rule obtained so as to perform fuzzy inference. The ROM 803 is for use as a membership function storage means and rule storage means, and stores control programs in addition to fuzzy rules and membership functions. Numeral 804 denotes a RAM used for a work area when fuzzy inference is performed.
Numeral 820 denotes a charge unit shown in FIG. 16. It is, for example, constructed as follows. That is, the numeral 180 is a surface potential sensor employed as a state quantity detection means which detects the surface potential of the drum 131. Numeral 181 denotes a room temperature sensor as a state quantity detection means which detects room temperature. Numeral 813 denotes an A/D converter which converts an analog signal from the surface potential sensor 180 and the room temperature sensor 813 to a digital signal. Numeral 814 denotes a D/A converter which converts a digital signal from the CPU 801 to an analog signal. Numerals 141, 143, and 142 denote a transfer high voltage, a separation high voltage, and a post high voltage, respectively. Each of these high voltages are output in accordance with an instruction input from the CPU 801 via the D/A converter 814.
In the control apparatus 800 (FIG. 16), numerals 801, 300, 400, 803 and 805 denote the same portions as in FIG. 16.
Numeral 807 denotes an interface (I/0), for transferring an output signal, which outputs a control signal to a load of a main motor 133 or the like. Numeral 809 denotes an interface, for transferring an input signal, which accepts an input signal from an image sensor and outputs it to the CPU 801. Numeral 811 denotes an interface which controls the input and output from a key group 600 and a display group 700. In the interfaces 807, 809, and 811 a μPD8255 (input and output circuit ports manufactured by NEC Corp.) is used.
FIG. 17 is a flowchart showing the control procedure by the CPU 801.
When there occurs a key input in step S1, fuzzy control is performed in step S2 and a copy is started in step S3.
In the fuzzy control of this embodiment, of environmental factors, original density (toner amount after development process, amount of toner charges), types (thickness, size) of transfer paper, status (status of water content =electrical resistivity) of transfer paper, dirtiness of a charger, transfer speed of paper, and a lot of fuzzy variation factors (state quantities) related to each other, as state quantities, for example, ○1 room temperature and ○2 original density, are used and, as operation amounts, for example, (a) transfer high voltage input, (b) separation high voltage output, and (c) post high voltage output, are used. The membership functions of these sets are shown in FIGS. 19A to 19E. FIG. 19A shows membership function for room temperature. FIG. 19B shows a membership function for original density. FIG. 19C shows a membership function for post high voltage output. FIG. 19D shows a membership function for transfer high voltage output. FIG. 19D shows a membership function for separation high voltage output.
As will be understood from FIGS. 19A to 19E, the factors of room temperature, original density, transfer high voltage output, separation high voltage output, and post high voltage output have three fuzzy sets each.
For example, for the three fuzzy sets of the room temperature, fuzzy labels are given with "TL", "TM", and "TH";
TL (Temperature Low): fuzzy set representing "room temperature is low".
TM (Temperature Medium): fuzzy set representing "room temperature is medium".
TH (Temperature High): fuzzy set representing "room temperature is high".
The degree belonging to each set takes any value between "0" to "1". In the case of a fuzzy set given with a fuzzy label TM shown in FIG. 19A, the degree belonging to a set of room temperature 25° C., namely, suitability, is "1.0" and suitability in the case of room temperature 18° C. or 32° C. is "0.5".
To determine post high voltage output, the fuzzy rules of the following rules 1 and 2 are used:
Rule 1 If x =TH and y =DM then z =PL
Rule 2 If x =TM and y =DM then z =PM
where x =room temperature, y =original density, and z =post high voltage output. These rules are shown in Table 1 as a rule table.
FIG. 18 is a flowchart showing the control procedure in Step 2 shown in FIG. 17.
Room temperature is measured in step S21 and original density is measured in step S22. In step S23, the amount of the post high voltage output is determined on the basis of rules 1 and 2, and the inference method. In step S24, similarly, the amount of the transfer high voltage output is determined. In step S25, similarly, the amount of the separation high voltage output is determined.
Next, a method of determining the amount of post high voltage output will be explained on the basis of rules 1 and 2, and the inference method.
If inference is performed according to rule 1, it is included in the set of TH at a degree of μx from the membership function for room temperature with respect to room temperature x° C. The inference is included in the set of DM at a degree of μy from the membership function for original density with respect to original density y. The minimum values determined regarding μx and μy are taken and the minimum values are defined to be degrees that satisfy the conditions of rule 1. A MIN operation of the value and the membership function for the post high voltage output is performed. The shape of the calculation results will become a trapezoid shown in the shaded portion of a set S shown in FIG. 21.
Next, when inference is performed according to rule 2, the shape of the calculation results will become the trapezoid shown in the shaded portion of a set T shown in FIG. 20.
Then, the determined inference results of each rule, i.e., the shaded portions of the sets S and T, are combined. The combined result becomes the shaded portion of a set U shown in FIG. 20. By calculating the center of gravity of this set, the post high voltage output is determined. The methods of determining transfer high voltage output and separation high voltage output do not substantially differ from the method of determining the post high voltage output. Tables 2 and 3 show rules in a case where transfer high voltage output and separation high voltage output are determined respectively, as a rule table.
In this embodiment, fuzzy rules, membership functions, control programs and so forth are stored in ROMs and calculation is performed using RAMs. However, a ROM which outputs an amount of operation corresponding to an input of a state quantity may be used. State quantities are not limited to the potential on the surface of a light-sensitive drum and room temperature. If they are state quantities relating to the charged state of a charging means, such as an original density read out by an original reading means, ambient humidity, water content state of transfer paper, the accumulated number of copied sheets, types (thickness, etc.) of transfer paper, transfer speed of transfer paper, dirtiness of a charger and so on, they may be used as the state quantities of the present invention. Also, an operation quantity is not limited to transfer high voltage, separation high voltage, or post high voltage, but high voltage of an electrostatic discharger or a primary charger may be used.
As regards post high voltage output control. a qualitative relation between state quantities and a control quantity are, for example, as shown in Table 4 below.
On the basis of this table, a rule table shown in Table 1 above may be created for inference. On that occasion, the number of state quantities is not limited to 2, but any number of these can be combined.
Likewise, an example in the case of the transfer high voltage is shown in Table 5 and that of the separation high voltage is shown in Table 6.
The algorithm of the above-mentioned fuzzy inference is one example. The algorithm may be modified. For example, instead of taking the center of gravity of maximum values of areas when a plurality of rules are combined, the value on the horizontal axis with respect to a value which becomes maximum on a vertical axis may be taken as an inference result. The number and contents of fuzzy rules may be modified on the basis of past experience.
As has been described above, according to the present invention, in a transfer and separation apparatus, the performance of which is determined by the environmental factors, original density (toner amount after development process, amount of toner charges), types (thickness, size) of transfer paper, status (status of water content =electrical resistivity) of transfer paper, dirtiness of a charger, transfer speed of paper, and a lot of fuzzy variation factors (state quantities) related to each other, high voltage output control can be performed automatically by calculating the optimum control amount from these control amounts complexly related to each other. As a result, a laborious adjustment at the time of shipment from the factory is not required and the service personnel are not required to take the trouble to make an adjustment. Further, there exists an advantage in that the maximum performance at the state can be exhibited at all times without depending on an expensive apparatus.
That is, according to the above-mentioned environmental factors, by providing a control, in which complex factors are considered, to the high voltage output of a charging means in which a control fixed with respect to the changes in the environment is performed in the prior art, efficient, accurate control can be performed. Since the control quantity is determined on the basis of a plurality of parameters at that juncture, if an error occurs in some input data, a greater error can be prevented from occurring in the control quantity.
As has been described above, according to the present invention, in an picture image forming apparatus, such as a copier, a laser printer or the like, which varies greatly due to the environmental factors and changes with time, and controlled by an ambiguous relation between state quantities and control quantities, a control quantity can be calculated from many kinds of state quantities complexly related to each other, and the control of a process means can be performed according to environmental factors, original density, past performance or the like at that time. As a result, the control of latent image potential, a development bias or the like, can be automated and substantial manual labor can be eliminated. Control under which many kinds of state quantities are taken into consideration can be effected without performing a lot of preliminary experiments, although it is a simple program and an image having a stable quality can be provided at any time.
In addition, according to this embodiment, by representing the algorithm of an ambiguous control based on an experience of a human being in objective functions and rules, a high degree of automatic control of a process means close to the feeling of a human being can be effected.
Many widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, therefore it is to be understood that this invention is not limited to the specific embodiments thereof except as defined in the appended claims.
TABLE 1______________________________________ Original Density DL DM DH______________________________________Temperature TL PH PH PH TM PM PM PM TH PL PL PL______________________________________
TABLE 2______________________________________ Original Density DL DM DH______________________________________Temperature TL IL IL IL TM IM IM IM TH IH IH IL______________________________________
TABLE 3______________________________________ Original Density DL DM DH______________________________________Temperature TL SM SL SL TM SH SM SM TH SH SH SH______________________________________
TABLE 4______________________________________State Room temperature (T) High LowQuantity Humidity (H) High Low The accumulated number (C) Small Large of copied sheetsControl Post high-voltage output Decrease IncreaseQuantity______________________________________
TABLE 5______________________________________State Room temperature (T) Low HighQuantity Humidity (H) Low High The accumulated number (C) Small Large of copied sheets Original density (D) Low High Thickness of paper (P) Thin ThickControl Post high-voltage output Decrease IncreaseQuantity______________________________________
TABLE 6______________________________________State Room temperature (T) Low HighQuantity Humidity (H) Low High The accumulated number (C) Small Large of copied sheets Original density (D) High Low Thickness of paper (P) Thick ThinControl Separation high-voltage output Decrease IncreaseQuantity______________________________________ | An image forming apparatus using electrostatic images includes a state quantity detection device for detecting states which would exert some influence on the formation of images as quantities, a control quantity control device for controlling the operation of a process for forming images on an image bearing member, a rule storage device for relating the relation between the state quantities and the control quantity by a control device as a certain rule and storing it, and an inference device for inferring a control quantity to be determined from a set of state quantities on the basis of rules of the rule storage device. The picture image forming apparatus determines the operation quantity for the image bearing member of the process device on the basis of the calculated results of the inference device and forms an image. | 8 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority of German Patent Application Serial No. 101 32 970.9, filed Jul. 6, 2001, pursuant to 35 U.S.C. 119(a)-(d), the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates, in general, to a mold mounting plate for an injection molding machine.
[0003] U.S. Pat. No. 5,593,711 describes a mold mounting plate for support of a mold of a plastics injection molding machine. The mold mounting plate includes a base plate, a frustoconical center portion, and a front plate in parallel relationship to the base plate. The base plate has corner regions provided with bores for receiving four tie bars of the injection molding machine. The center portion is configured as hollow body and has a base for attachment to a central location of the base plate. The blunted tip of the central portion is attached to the front plate for the mold. Thus, the front plate is supported solely in its central area by the center portion. In this way, the front plate of the mold mounting plate is intended to remain flat, even when subjected to the clamping force of the injection molding machine, to thereby prevent a deflection and resultant opening of the mold halves.
[0004] European Pat. No. EP 0 789 648 B1 discloses an injection molding machine having a substantially C-shaped machine frame having two limbs, which are not connected by tie bars. Mounted to one of the limbs is a fixed mold mounting plate, whereas a flange of a closing unit is secured to the other limb. The closing unit essentially includes a hydraulic piston and cylinder unit to shift the moveable mold mounting plate, which is displaceably supported on the machine frame. The flange and the fixed mold mounting plate are each secured by holding members to the limbs of the machine frame. During closing operation, the holding members of the flange are subject to tensile stress and the fixed mold mounting plate is subject to pressure. The holding members are functionally equivalents to springs and have an elasticity, which is smaller than the elasticity of the machine frame. Several holding members may be provided in spaced-apart disposition over the height of the fixed mold mounting plate and the flange and exhibit different elasticity, whereby the lower holding members have a greater elasticity than the upper holding members. The holding members are made of spring steel and weakened through provision of slots. Their lower portion has slots of different depth to enhance the elasticity. When the limbs of the machine frame are pushed apart in the upper zone during injection operation, the fixed mold mounting plate and the flange can tilt relative to the machine frame to maintain the mold mounting plates in parallel relationship. The holding members thus form an axleless joint to allow rotational motions as well as translational motions.
[0005] European Pat. No. EP 0 381 107 B1 discloses a closing unit for a horizontal two-platen injection molding machine for processing plastic material. The injection molding machine includes a fixed mold mounting plate and a moveable mold mounting plate in confronting disposition to support respective mold halves of the mold. The fixed mold mounting plate has a substantially rectangular configuration and is connected with the moveable mold mounting plate by four spindles positioned in the corners of an imaginary tetragon. The spindles are non-rotatably arranged and cantilevered on the fixed mold mounting plate. In order to close and open the mold, the moveable mold mounting plate can be moved in a direction to and away from the fixed mold mounting plate by the spindles, as it travels along the spindles. The drive for the moveable mold mounting plate is implemented by mounting on the side, facing away from the clamping surface for the mold, a spindle nut for each of the spindles, whereby all the spindle nuts rotate together in synchronism by a drive, e.g., electric motor. The spindle nuts are each constructed as ball nut. After closing the mold, the clamping force is applied on the mold halves by an additional hydraulic piston and cylinder unit, which acts on the spindle nuts. The piston and cylinder unit has an annular piston through which the respective spindle is guided. In order to allow opening of the mold halves after the injection molding process, the piston and cylinder unit is constructed as a double-action piston and cylinder unit.
[0006] When the mold mounting plates distorts or deforms, these deformations are transmitted to the spindles guided in the openings of the mold mounting plate, resulting in undesired bending stress of the spindles so that the parallelism between the spindles and between the spindles and the axis of the injection molding machine is no longer maintained. As a consequence, the spindles and/or the spindle drives are exposed to increased wear, reducing service life and leading ultimately to their destruction.
[0007] It would therefore be desirable and advantageous to provide an improved mold mounting plate of an injection molding machine to obviate prior art shortcomings and to minimize in a simple manner a transmission of moments onto column-like holding and/or guiding elements of the injection molding machine as a result of a deformation of the mold mounting plate.
SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a mold mounting plate for an injection molding machine for processing material, in particular plastic material, includes a main body having a plate-shaped central portion, plural sleeves received in the main body and defining openings for support of column-like holding and/or guiding elements of the injection molding machine, and a connection assembly for securing the sleeves to the central portion such as to establish a flexible bending/torsion joint.
[0009] The present invention resolves prior art problems by providing an elastic securement for a connection of the mold mounting plate to the holding and/or guiding elements through dividing the mold mounting plate into a rigid central portion and sleeves, which are supported elastically in the central portion. Suitably, the central portion and the sleeves are made of single-piece configuration, preferably a single-piece structure of cast steel.
[0010] According to another feature of the present invention, the central portion of the main body may have a substantially rectangular configuration and defines corner regions for arrangement of the sleeves in one-to-one correspondence, wherein the connection assembly may include in each of the corner regions a pair of legs, arranged in spaced apart relationship to define a U-shaped area and extending outwards, and a bolt arranged between the legs and provided for attachment of the sleeve. Upon application of a clamping force, the legs and the bolts are subjected to torsion and bending. Suitably, the sleeve is secured in midsection of the bolt at its side confronting the center portion. In order to enlarge the contact area between the sleeve and the bolt, the sleeve dips into the bolt, i.e. the sleeve is partly received in the bolt.
[0011] According to another feature of the present invention, the central portion may include an inner rib structure having opposite sides, and cover plates, one cover plate covering one side of the rib structure, and the other cover plate covering the other side of the rib structure, wherein the rib structure includes a central annulus, Y-shaped connecting ribs having one end secured to the annulus and being spaced from one another in a star-shaped manner, and peripheral ribs connected to another end of the Y-shaped connecting ribs. Thus, as the mold mounting plate is subjected to the clamping force, the cover plates are no longer required to absorb loads in the area of the flexible joint and thus, there is no need to extend the cover plates beyond the central portion, so that the weight of the mold mounting plate can be reduced.
[0012] Through configuration of the mold mounting plate with the rib structure, the stiffness of the mold mounting plate can be suited to the situation at hand by changing the vertical extension and position of the rib structure, so that a self-flexure of the mold mounting plate is minimized during the injection molding process.
[0013] A mold mounting plate according to the present invention is suitable for use in plastics injection molding machine without tie bars, whereby the mold mounting plates are connected hereby to the, normally U-shaped, machine frame by holding and/or guiding elements received in the openings of the sleeves. This support of the mold mounting plates without axle joint maintains the parallelism of the mold mounting plates, when the legs of the U-shaped machine frame yield as a result of the clamping force. Of course, a mold mounting plate according to the present invention is also suitable for use in so-called three-platen injection molding machines.
[0014] According to another feature of the present invention, the bolt may be arranged in eccentric relationship to the sleeve. Suitably, the sleeve defines a longitudinal axis, which is oriented at a right angle to the surface of the central portion, and the bolt defines a longitudinal axis, which is oriented at a right angle to the surface of the central portion and extends at a right angle to the longitudinal axis of the sleeve.
[0015] According to another feature of the present invention, the sleeve may be separated from the central portion by a gap on its outer surface facing the central portion. Suitably, the gap has a sickle-shaped configuration.
[0016] According to another feature of the present invention, the legs may be respectively connected to the bolt via rounded transitions, and the bolt is connected to the sleeve via a rounded transition. In this way, the sleeve, the bolt and the legs can be connected together in a notch-friendly manner.
BRIEF DESCRIPTION OF THE DRAWING
[0017] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:
[0018] [0018]FIG. 1 is a front elevational view of a mold mounting plate according to the present invention, partly broken to show the inner support structure; and
[0019] [0019]FIG. 2 is a side view of the mold mounting plate, taken along the line II-II in FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.
[0021] Turning now to the drawing, and in particular to FIG. 1, there is shown a front elevational view of a mold mounting plate according to the present invention, generally designated by reference numeral 1 for use in an injection molding machine, partly broken to show the inner support structure. For the sake of simplicity, the injection molding machine will be described hereinafter only in connection with those parts that are necessary for the understanding of the present invention. In general, an injection molding machine, involved here may be a two-platen injection molding machine for plastics and includes a machine frame, a fixed mold mounting plate mounted to the machine frame, and a movable mold mounting plate. The plates are provided with a closing unit, having several spindle drives with spindles, for opening and closing operations, whereby the spindles extend in the direction of the moveable mold mounting plate and through the corner regions of the moveable mold mounting plate as well as attached spindle nuts. These spindle nuts are caused to rotate by a drive to open and close molds secured to the mold mounting plates. Suitably, the spindle drives are ball screws. Operation and structure of such injection molding machines are generally known to the artisan and not further described in more detail. Injection molding machine without tie bars utilize column-like holding and/or guiding elements to secure the mold mounting plates to the machine frame.
[0022] The mold mounting plate 1 , which may be a fixed mold mounting plate or a movable mold mounting plate, includes a main body having a substantially rectangular central portion 2 which connects in its corner regions 2 a into two flat legs 3 arranged in U-shaped relationship. The legs 3 terminate in free ends 3 a , which face away from the central portion 2 . The legs 3 and each corner region 2 a of the center portion 2 define a generally U-shaped zone 4 , which is open to the outside, i.e. away from the central portion 2 .
[0023] Disposed in each of the four U-shaped zones 4 is a sleeve 5 which has a through opening 6 for receiving the column-like holding and/or guiding elements 9 of the injection molding machine, shown here by way of example at one sleeve 5 . As the U-shaped zones 4 are of identical construction, it will be understood by persons skilled in the art that a description of one U-shaped zone 4 is equally applicable to the other U-shaped zones 4 . The sleeve 5 in the U-shaped zone 4 defines a longitudinal axis I (FIG. 2), which extends at a right angle to the surface 1 a of the main body of the mold mounting plate 1 . In midsection thereof, the sleeve 5 is connected to a bolt 7 for securement to opposite free ends 3 a of the legs 3 . The bolt 7 is suitably designed as solid cylinder and is defined by a longitudinal axis L, which extends at a right angle to the surface 1 a of the main body of the mold mounting plate 1 and at a right angle to the longitudinal axis I of the sleeve 5 . The sleeve 5 is also arranged eccentrically to the bolt 7 , i.e. the longitudinal axes L and I extend in lateral spaced-apart disposition, as indicated in FIG. 1 by reference character “a”.
[0024] The bolt 7 abuts with its opposite axial ends the confronting inner sides of the legs 3 . In order to realize a large-area connection between the sleeve 5 and the bolt 7 , the sleeve 5 is received in an arcuate recess of the bolt 7 . Suitably, the sleeve 5 dips into the bolt 7 by about up to ⅔ of its thickness and thus by about half its diameter. The transition 5 a between the sleeve 5 and the bolt 7 and the transitions 7 a between the free ends of the legs 3 and the bolt 7 are configured in a notch-friendly manner as radii. As a consequence of this type of connection between the sleeve 5 and the center portion 2 , the sleeve 5 is separated in the area of its side confronting the center portion 2 by a gap 8 , which has a generally sickle-shaped configuration and extends about 180° with respect to the center of the sleeve 5 . The gap 8 is bounded at its ends by the bolt 7 .
[0025] Due to the configuration of the webs 3 and the type of suspension of the sleeve 5 via the bolt 7 , the sleeve 5 juts out beyond the imaginary rectangular contour of the center portion 2 by about a quarter of its diameter.
[0026] The legs 3 and the bolt 7 form an elastically yielding connection of the sleeve 5 with the center portion 2 , so that deflections of the mold mounting plate 1 as a result of an applied clamping force is transmitted to the sleeve 5 to a lesser extent. The legs 3 and the bolt 7 are subjected to torsion and bending. The elasticity of the legs 3 and the bolt 7 is so selected that, under impact of the column-like holding and/or guiding elements of the injection molding machine and the load on the mold side of the mold mounting plate 1 , not only the holding and/or guiding elements remain in parallel relationship but the center portion 2 of the mold mounting plate 1 remain also essentially flat. Thus, the holding and/or guiding elements will hardly be subject to bending forces.
[0027] As is further shown in FIG. 1, the center portion 2 of the mold mounting plate 1 is designed in lightweight construction with upper and lower cover plates 2 b and a rib structure positioned between the cover plates 2 b . As viewed in top plan view, the rib structure includes a central annulus 2 c , Y-shaped connecting ribs 2 d and peripheral ribs 2 e . The four connecting ribs 2 d are evenly spaced about the circumference of the annulus 2 c in a star-like manner and connected to the annulus 2 c with one end. The other fork-shaped ends of the Y-shaped connecting ribs 2 d are connected to the peripheral ribs 2 e arranged between the cover plates 2 b in a marginal region thereof. Thus, the center portion 2 has a tetragonal outer contour with retracted corner regions 2 a in the area of the Y-shaped connecting ribs 2 d . The legs 3 also connect into the junction zone between the Y-shaped connecting ribs 2 d and the peripheral ribs 2 e.
[0028] The configuration of the mold mounting plate 1 with the rib structure and the sleeves 5 , connected to the rib structure via the legs 3 and the bolts 7 , is in particular suitable for a single-piece design of the mold mounting plate 1 as a casting, preferably as cast steel member Thus, the mold mounting plate 1 may be made in an especially simple manner.
[0029] The rib structure of the mold mounting plate 1 can be clearly seen in FIG. 2, which is a side view of the mold mounting plate, taken along the line II-II in FIG. 1, including the perpendicular orientation of the longitudinal axis I of the sleeve 5 relative to the surface 1 a of the center portion 2 . Also clearly shown is the radius-like transition 7 a between the bolt 7 and the leg 3 .
[0030] While the invention has been illustrated and described as embodied in a mold mounting plate for an injection molding machine, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
[0031] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents: | A mold mounting plate for an injection molding machine for processing material, in particular plastic material, includes a main body having a plate-shaped central portion. Received in the main body are plural sleeves which define openings for support of column-like holding and/or guiding elements of the injection molding machine, and are secured to the central portion such as to establish a flexible bending/torsion joint. In this way, a transmission of moments onto the column-like holding and/or guiding elements as a result of a deformation of the mold mounting plate is minimized. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a rotary piston engine and, more particularly, a method of and a device for supplying fuel to a stratified combustion rotary piston engine.
2. Description of the Prior Art:
In the so-called Wankel-type rotary piston engine which comprises a casing composed of a rotor housing having a trochoidal inner peripheral surface and side housings which close opposite sides of said rotor housing and a polygonal rotor adapted to rotate eccentrically in said casing with apex portions thereof sliding over said inner peripheral surface, the flame initiated from an ignition plug propagates very swiftly toward the leading side located at the front side of the rotor as seen in the rotational direction of the rotor due to the flow of fuel-air mixture caused by the rotation of the rotor. However, the propagation of the flame toward the trailing side located at the rotationally rear side of the rotor is relatively impeded, whereby there exists the problem that although the fuel-air mixture is favorably combusted in the leading side, the combustion is incomplete in the trailing side thereby lowering the combustion efficiency with the results of increasing the fuel consumption and simultaneously increasing the emission of harmful uncombusted components such as HC and CO in the exhaust gas. In order to solve this problem, I have proposed a rotary piston engine having a first intake port which opens in said trochoidal inner peripheral surface and a second intake port which opens in an inner surface of said side housing at a position advanced from said first intake port with respect to the rotational direction of the rotor. The first intake port is supplied with a fuel-air mixture while said second intake port is supplied with only air, thereby providing a stratified charging in a manner that the leading side portion of the combustion chamber where the combustion of the fuel-air mixture is relatively easily effected is filled with a relatively rich fuel-air mixture, whereas the trailing side of the chamber where the combustion of the fuel-air mixture is difficult to achieve is filled with only air.
In this stratified combustion rotary piston engine, the particular manner of combustion improves the fuel consumption when compared with the conventional rotary piston engine and, simultaneously, contributes to reducing the emission of HC and CO in the exhaust gas. However, since the emission of HC and CO is not completely reduced to zero, it is required that those components remaining in the exhaust gas are processed in a thermal reactor. Since it is required that temperature of the exhaust gas must be above a certain level if an effective operation of the thermal reactor is to be accomplished, the lowering of the exhaust gas temperature in the abovementioned stratified combustion causes the problem that the purifying performance of the thermal reactor is substantially lowered.
Furthermore, although the amount of NOx contained in the exhaust gas of the rotary piston engine is very small when compared with the reciprocating engines so that it meets the present-day regulations for emission control without any countermeasures being required, it is expected that the regulations regarding exhaust gas will become more severe in the near future and, therefore, the current rotary piston engine will soon violate the regulations with regard to NOx emission.
It is known that generally there exists a relation such as shown in FIG. 1 between the air/fuel ratio and the emission of HC, CO and NOx in the exhaust gas of a gasoline engine. In FIG. 1 the scales for CO, HC and NOx are particularly adapted for the case of the rotary piston engine. As apparent from FIG. 1, the NOx content in the exhaust gas is a maximum when the air/fuel ratio is about 15-16 but lowers relatively steeply as the air/fuel ratio increases or decreases from the abovementioned value. The present anti-air pollution rotary piston engine employs an air/fuel ratio of about 12-13, whereby the emission of NOx is restricted within an acceptable limit while the HC and CO delivered in this operational condition are eliminated by recombusting in a thermal reactor. However, if, for example, the limit value of 0.25 g/km for NOx, which is expected to be enforced in the near future, is to be satisfied, the NOx content must be lower than 130 ppm. To accomplish this, the air/fuel ratio must be either substantially low, that is, in the order of about 11-12 or, on the contrary, must be relatively high, that is, in the order of about 18-19. If the air/fuel ratio is lowered to the order of 11-12, the amount of HC and CO substantially increases beyond the limit which can be processed by the present thermal reactor or catalyst. On the other hand, if the air/fuel ratio is increased as high as about 18-19, the ignitability of fuel-air mixture becomes poor thereby causing misfiring and making it difficult to maintain a smooth operation of the engine. In this condition, the CO content is almost zero and, although the amount of HC relatively increases when compared with its minimum value, its absolute value is still acceptable and it is still possible to process the uncombusted components by the present thermal reactor or catalyst.
SUMMARY OF THE INVENTION
The present invention is based upon the consideration regarding the aforementioned relationship between the air/fuel ratio and the emission of HC, CO and NOx and contemplates providing an air-pollution free stratified combustion clean engine which can maintain a smooth operation while supressing the emission of NOx within the limit to satisfy the regulations, simultaneously suppressing the emission of HC and CO within the limit to be processed by a thermal reactor or catalyst while maintaining the temperature of the exhaust gas at a sufficiently high level required for the post processing by the thermal reactor or catalyst. Accordingly, the object of the present invention is to provide a novel system for supplying fuel to the air-pollution free, stratified combustion, clean engine based upon the aforementioned principle.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
According to the present invention, the abovementioned object is accomplished by a device and method for supplying fuel to a rotary piston engine of the type comprising a casing composed of a rotor housing having a trochoidal inner peripheral surface and side housings which close opposite ends of said rotor housing, and a polygonal rotor adapted to rotate eccentrically in said casing with apex portions thereof sliding over said trochoidal surface while defining a plurality of combustion chambers between said trochoidal surface and individual flanks of said polygonal rotor. The casing has first and second intake ports which open in the inner wall of said casing, said second port being positioned as advanced in the rotational direction of said rotor relative to said first port, wherein the improvement comprises supplying fuel-air mixture through said first port while supplying only air through said second port, said supply of fuel and air being controlled so that the overall air/fuel ratio determined by the fuel-air mixture supplied through said first port and the air supplied through said second port is altered according to a predetermined order for said plurality of combustion chambers.
According to the abovementioned method, for example, a first combustion chamber which performs the suction stroke in the first of said order is supplied with a relatively rich fuel-air mixture having the air/fuel ratio in the order of 11-12 and a second combustion chamber which performs the suction stroke in the second of said order is supplied with a relatively lean fuel-air mixture having the air/fuel ratio in the order of 18-19, the subsequent combustion chambers being supplied with relatively rich or lean fuel-air mixtures, alternately in the same manner. Under this operating manner, the exhaust gas delivered from the rotary piston engine will show a low NOx value like below 130 ppm with respect to any combustion chamber operating with either the rich or the lean fuel-air mixture. As for the CO content, the exhaust from the combustion chamber which operates with a relatively rich fuel-air mixture will show about 7% emission of CO while the exhaust from the combustion chamber which operates with the relatively lean fuel-air mixture will show substantially zero emission of CO, thus resulting in the mean value of CO emission in the order of 3.5% which is lower than the 4% emission in the conventional operation with an air/fuel ratio of about 13, provided that the effect of the stratified combustion is omitted, said effect, however, acting favorably in reducing the content of CO, HC and NOx. With regard to HC, the emission will slightly increase. However, since the absolute value of HC is relatively low, the overall content of the uncombusted components resulting from HC and CO is still limited within the range which can be treated by the conventional thermal reactor. Furthermore, because a relatively high exhaust gas temperature is obtained in the rich combustion phase of the alternate combustion of the rich and the lean fuel-air mixtures, even when the overall air/fuel ratio is relatively high, recombustion of the uncombusted components in the thermal reactor is effected in a high efficiency.
In the combustion chamber supplied with the relatively lean fuel-air mixture of the air/fuel ratio in the order of 18-19, the probability of causing misfiring is relatively high due to poor ignitability of the lean fuel-air mixture. Therefore, if the rotation of the rotor is to be maintained only by such lean combustion, the operation of the engine will become unstable. However, since in the present invention the rotation of the rotor is assisted by the stable combustion effected in the combustion chambers supplied with the rich fuel-air mixture of the air/fuel ratio in the order of 11-12, the rotation of the rotor is stably maintained. Thus, the present invention accomplishes a reduction of NOx, the most difficult component to reduce, to the order of 130 ppm which is the limit expected to be enforced in the near future, while simultaneously supressing CO and HC within an acceptable limit and ensuring smooth and stable operation of the engine.
According to a particular feature of the present invention, the aforementioned periodical alteration of the overall air/fuel ratio may be effected by increasing or decreasing the amount of fuel contained in the fuel-air mixture supplied through said first intake port, i.e., by altering the air/fuel ratio of the fuel-air mixture supplied through said first intake port.
According to another particular feature of the present invention, said periodical alteration of the overall air/fuel ratio may be effected by increasing or decreasing the amount of air supplied through said second intake port while correspondingly decreasing or increasing the amount of air supplied as a fuel-air mixture through said first intake port, thereby altering the amount of fuel relative to the total amount of air supplied to the engine.
As a device for supplying fuel in the abovementioned manner to the rotary piston engine of the abovementioned type, the present invention proposes a device comprising a fuel air mixture supply system including a fuel injection means for supplying fuel-air mixture through said first port and an air supply system for supplying air through said second port, wherein the improvement comprises a control means for controlling said fuel injection means so as to generate relatively rich fuel-air mixture or relatively lean fuel-air mixture according to a predetermined order for said plurality of combustion chambers.
By supplying fuel in the injecting manner by employing the abovementioned fuel supply device, the amount of fuel supplied to individual combustion chambers can be controlled in a very high responsiveness by regulating the time for injecting fuel so that the amount of fuel is altered in a high precision for every combustion chamber which successively performs the suction stroke thereby effecting the abovementioned alternating combustion between the rich and lean fuel combustion.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein,
FIG. 1 is a graph showing the emission of CO, HC and NOx in the exhaust of a gasoline engine with respect to air/fuel ratio, the graph being particularly scaled for the case of a rotary piston engine;
FIG. 2 is a diagrammatic view showing the basic constitution of the rotary piston engine incorporating the fuel supply system according to the present invention, and,
FIG. 3 is a longitudinal section of an example of a fuel injection means employable in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 2, a rotor housing 2 having a trochoidal inner peripheral surface 1 is assembled with side housings 4 each having a flat inside surface 3 to provide a casing, for housing a triangular rotor 5. The rotor is provided to be rotatable eccentrically around an eccentric shaft 9 with its apex seals 6a-6c provided at its three apex portions contacting said trochoidal surface. Side seals 7 are provided along three side edges and simultaneously contact said inner surface 3 of the side housing under the meshing of an internal gear 8 thereof with a fixed gear 10 of the eccentric shaft 9. The rotor 5 in the casing defines three combustion chambers 12a-12c by its three arcuate peripheral flanks 11a-11c cooperating with said trochoidal inner peripheral surface. For the three combustion chambers, said three arcuate flanks 11a-11c provide recesses 13a-13c at a central portion thereof, respectively. Adjacent a short axis portion 14 of the trochoidal inner peripheral surface 1 of the rotor housing 2 are provided two ignition plugs 15, while adjacent another short axis portion 16, located rearward as seen in the rotational direction of the rotor, an exhaust port 17 is provided, said port being connected with an exhaust manifold 18. Adjacent the short axis portion 16, located forward as seen in the rotational direction of the rotor, a peripheral intake port 19 is provided and, as located further advanced therefrom in the rotational direction of the rotor, a side intake port 20 is provided to open in the side housing 4. In this case, the peripheral intake port 19 provides a relatively small constant opening area for a range of rotational angle of the eccentric shaft extending before and after of the top dead center while, in contrast, the side intake port 20 provides an opening area which varies in a manner to steeply increase after the rotational angle of the eccentric shaft has traversed the top dead center, then reaching its maximum which is several times larger that the opening area of the peripheral intake port about at the time when the peripheral intake port is closed and, thereafter, steeply decreasing toward zero.
The ports 19 and 20 are connected with first and second intake manifolds 21 and 22, respectively, these intake manifolds being connected at their inlet ends to a throttle body 23. The throttle body 23 is formed as a duplex throttle body having a first air supply passage 24 communicating with the intake manifold 21 and a second air supply passage 25 communicating with the intake manifold 22. The air supply passages 24 and 25 are provided with throttle valves 26 and 27, respectively, which are adapted to be driven independently from each other by individual actuators 28 and 29. The actuators may be an optional link mechanism adapted to be mechanically driven by an accelerating pedal or an electrical device employing a small electrical motor electrically controlled by a computer 30 according to the operation of an acceleration pedal. At the entrance of the throttle body 23 is mounted an air cleaner 31 and in the individual air passages 24 and 25 connected to the air cleaner are provided air flow sensors 32 and 33. These air flow sensors may be a well known heat wire sensor employing a thermal sensitive resistor element or a flapper sensor employing a flow sensitive flapper element adapted to despatch an electric signal according to the air flow detected thereby. The electric signals from these sensors are supplied to the computer 30.
Note, the electric computer 30 may, for example, be a slight modification of the electronic system disclosed in FIG. 7 of U.S. Pat. No. 3,827,237.
The first air supply passage 21 is provided with a fuel injection means 34 which injects fuel into the passage according to an injection signal supplied from the computer 30. The fuel injection means 34 may, for example, be an electro-magnetic fuel injection means as shown in FIG. 3. The fuel injection means shown in FIG. 3 comprises a body 35 and a solenoid casing 36 which encloses the body 35 while supporting therein a solenoid 37, said solenoid being adapted to draw a plunger 38 when it is energized by a driving pulse current supplied from the computer 30 thereby shifting a needle valve body 39 mounted to the plunger toward a valve opening position against the action of a compression coil spring 40, thus opening an injection opening 42 provided at a tip end of a nozzle casing 41 mounted at the tip end portion of the solenoid casing 36. A fuel supply tube 43 is connected to the rear end of the body 35 so that the fuel supplied through said fuel supply tube flows through a central bore formed in the body 35, the plunger 38 and a portion of the needle valve body 39 as shown by arrows in the figure to be ejected from the injection opening 42 toward the air supply passage 21. The amount of fuel injected in the abovementioned manner is regulated by the time in which the needle valve is opened, i.e., the time in which the solenoid 37 is energized, because the stroke of the needle valve is constant.
The computer 30 is supplied with a timing signal for indicating the time for making fuel injection from a distributor 45 which may be a conventional one equipped in the conventional rotary piston engine. The computer 30 sends the ignition signal to the fuel injection means 34 in the form of a combination of a relatively long pulse and a relatively short pulse arranged in a predetermined order as synchronized to the timing signal supplied from the distributor 45, wherein the pulse length is increased or decreased according to the total air flow detected by the air flow sensors 32 and 33. By this arrangement, supposing that, for example, the combustion chamber 12a initiates the performance of the suction stroke, the computer 30 sends a relatively long pulse ignition signal to the fuel injection means 34 depending upon the timing signal received from the distributor 45 thereby making the fuel injection means 34 inject fuel for a time corresponding to the pulse length of the relatively long pulse, thus supplying relatively rich fuel-air mixture to the combustion chamber 12a. When the rotor 5 has rotated so far that the next combustion chamber 12c initiates the performance of the suction stroke, the computer 30 sends the next relatively short pulse of the ignition signal to the fuel injection means 34 according to the timing signal received from the distributor 45, whereby the fuel injection means 34 makes injection of fuel for a short time corresponding to the relatively short pulse length thereby supplying a relatively lean fuel-air mixture to the combustion chamber 12c. In the further rotation of the rotor, for each combustion chamber which performs the suction stroke, the fuel injection means 34 injects fuel into the air supply passage 21 for a relatively long or short time according to the injection signal thereby supplying a relatively rich or lean fuel-air mixture to the individual combustion chambers, said fuel-air mixture forming the stratified charge in the individual combustion chambers together with the air supplied through the second air supply passage 22 and the side intake port 20.
The order in the repetition of charging the relatively rich and lean fuel-air mixtures need not be a strict alternation of one charge of each type but the sequence may be determined so that one charge of a relatively rich fuel-air mixture may be followed by two or three charges of a relatively lean fuel-air mixture.
Furthermore, although the present invention has been illustrated and described with reference to the embodiment having a peripheral intake port and a side intake port, the latter being positioned as advanced from the former as seen in the rotational direction of the rotor, the present invention is not limited to this structure and it is also applicable to the rotary piston engine which operates with two peripheral intake ports or two side intake ports. | In a stratified combustion rotary piston engine of the Wankel-type wherein individual combustion chambers are charged with a fuel-air mixture by a fuel-air mixture supply system and air by an air supply system, a fuel supply system incorporated in said fuel-air supply system being adapted to supply fuel in the injection manner by varying the amount of fuel to be injected for individual combustion chambers so that the overall air/fuel ratio is altered for the individual combustion chambers. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication system and method, and a storage medium storing programs in communication system.
2. Related Background Art
A remote monitor system using a plurality of video cameras and a synthesizer for synthesizing in an analog manner images taken with the cameras has been used in a building of a relatively small scale or the like and such as system is called a local monitor system. In contrast to such a local monitor system, a remote monitor system has been proposed in which a plurality of cameras are connected by a digital network such as LAN (local area network) and public digital line ISDN so that the more cameras at remoter sites can be controlled more flexibly.
Of remote monitor systems, some systems control the image display and system operations through graphical user interface (GUI) by using personal computers or work stations as monitor terminals. Use of GUI at a monitor terminal enables a computer device to operate the system easily. The operability of the system can be improved by displaying a camera control panel together with an image taken with the camera.
However, conventional methods of displaying images with such a system include various methods such as a glance display of images taken with a plurality of cameras. A conventional display operation and discrimination between system operations are not always good heretofore. Personal computers and work stations are directly, or via a synthesizer for image synthesis and a switcher for switching between cameras, connected to the network. The image synthesizer can select one of cameras connected thereto to display its image, or can display a plurality of images side by side at the same time. By using the switcher, any desired camera can be selected to be controlled.
However, the operability of the system which inputs images via the switcher/synthesizer is not so much satisfactory and there is still a room to be improved.
SUMMARY OF THE INVENTION
It is an object of the present invention to solve the above problems and provide a communication system and method and a storage medium storing communication system programs, capable of providing flexible operations.
It is another object of the present invention to provide a communication system and method having user interface (UI) capable of being flexibly operated upon and provide a communication system and method and a storage medium storing communication system programs, capable of switching, when necessary, between a glance display mode of displaying images supplied from a plurality of communication terminals and a fine display mode of displaying a single image taken with each camera.
According to one aspect of the present invention achieving the above objects, a communication system comprises reception means for receiving images generated by image generating units of a plurality of communication terminals, output means for outputting a multi-image of images received by the reception means to a display unit, designation means for designating an arbitrary image from the images constituting the multi-image, and processing means for controlling the output form of an image to be output to the display unit, the image being designated by the designation means, if a designation operation by the designation means is a first designation operation, and for setting the communication terminal as a control object, the communication terminal generating an image designated by the designation means, if a designation operation by the designation means is a second designation operation.
It is another object of the present invention to improve the operability of the system when images are supplied via a switcher or synthesizer.
It is another object of the present invention to provide a communication system and method and a storage medium storing communication system programs, having novel functions.
The other objects and aspects of the present invention will become more apparent from the following detailed description and appended claims when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram briefly showing the overall structure of a system according to a first embodiment of the invention.
FIG. 2 is a block diagram showing the outline structure of a video transmission terminal of the first embodiment.
FIG. 3 is a block diagram showing the outline structure of a video reception terminal (monitor terminal) of the first embodiment.
FIG. 4 is a block diagram showing the configuration of software of the first embodiment.
FIG. 5 shows examples of the display contents on the screen of the monitor terminal of the first embodiment.
FIG. 6 is a diagram showing an example of a map window in which a map is displayed at the front of the window.
FIG. 7 illustrates an operation of starting an image display.
FIG. 8 is a diagram showing an example of the shape of a mouse cursor during the image display start operation.
FIG. 9 is a diagram showing an example of a camera icon during the image display.
FIG. 10 is a flow chart illustrating a power turnoff process.
FIG. 11 is a diagram illustrating the operation of changing a video display area.
FIG. 12 is a diagram illustrating the operation of stopping an image display.
FIG. 13 is a diagram showing an example of an image display window in a watching mode.
FIGS. 14A and 14B are diagrams showing examples of an image quality setting panel.
FIG. 15 is a block diagram briefly showing the overall structure of a system according to a second embodiment of the invention.
FIG. 16 is a diagram showing a display example in the glance display mode, a synthesized image of images being displayed which are supplied from a video transmission terminal connected to a plurality of video cameras via the synthesizer and switcher.
FIG. 17 is a diagram showing a display example in the glance display mode, a single image being displayed which is selected from images taken with a plurality of video cameras connected via the synthesizer and switcher to the video transmission terminal.
FIG. 18 is a block diagram showing the outline structure of the video reception terminal (monitor terminal) of the second embodiment.
FIG. 19 is a block diagram showing the outline structure of software of the second embodiment.
FIG. 20 is a diagram showing a monitor example of the monitor terminal of the second embodiment.
FIG. 21 is a diagram showing a display example when the single image display window is popped up.
FIG. 22 is a diagram showing a display example in the single image display mode, a single image being displayed which is selected from images taken with a plurality of video cameras connected via the synthesizer and switcher to the video transmission terminal.
FIG. 23 is a diagram showing a display example in the glance display mode, a synthesized image of images being displayed which are supplied from a video transmission terminal connected to a plurality of video cameras via the synthesizer and switcher.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
<First Embodiment>
FIG. 1 is a block diagram briefly showing the structure of an overall system according to an embodiment of the invention. A digital network 10 transfers digital signals of video data and camera control information (inclusive of status information). The digital network 10 is connected to n video transmission terminals 12 ( 12 - 1 to 12 -n). Each video transmission terminal 12 is connected via a camera controller 14 ( 14 - 1 to 14 -n) to a video camera 16 ( 16 - 1 to 16 -n). In accordance with a control signal supplied from the terminal 12 , the camera controller 14 controls panning, tilting, zooming, focussing, diaphragming, and the like of the connected video camera 16 . The video camera 16 is supplied with power from the camera controller 14 which in accordance with an external control signal received from a video reception terminal 18 ( 18 - 1 to 18 -m), turns on and off the power.
The network 10 is also connected to m video reception terminals 18 which receive video signals transmitted from the video transmission terminals 12 via the network 10 and display them on m monitor displays (hereinafter abbreviated as monitors) 20 ( 20 - 1 to 20 -m).
The video transmission terminal 12 compresses video signals output from the connected video camera 16 in a predetermined compression format such as H.261, MPEG, and Motion JPEG and transmits the compressed video signals to the video requesting video reception terminal 18 or to all the video reception terminals 18 . The video reception terminal 18 received the video signal operates to display the image in a video display area of the monitor 20 . The video reception terminal 18 can control, via the network 10 , video transmission terminal 12 , and camera controller 14 , various parameters (such as photographing direction, magnification factor, focus, and diaphragm) as well as a power supply (from on to off or vice versa) of any one or ones of desired cameras 16 . The details of this will be later described in detail.
A video reception terminal may be realized by providing the video transmission terminal 12 with a monitor and a video expansion device for expanding compressed video signals. Similarly, a video transmission terminal may be realized by providing the video reception terminal 18 with a camera controller, a video camera, and a video compression device. In this case, it is obvious that software for video transmission or reception is also provided.
FIG. 2 is a block diagram showing the outline structure of the video transmission terminal 12 . Reference numeral 22 represents a CPU for controlling the entirety of the terminal 12 , reference numeral 24 represents a main storage, reference numeral 26 represents a removable external storage unit such as a floppy disk and a CD-ROM, reference numeral 28 represents a secondary storage unit such as a hard disk, reference numeral 30 represents a mouse as a pointing device, reference numeral 32 represents a keyboard, reference numeral 34 represents an I/O board for interface with the camera controller 14 and transfer of a camera control signal, and reference numeral 36 represents a video capture board for receiving a video signal output from the video camera 16 . The video capture board 36 of this embodiment has an A/D conversion function of converting an analog video signal into a digital video signal and a function of compressing video signals. Reference numeral 38 represents a video board for displaying images on the screen of a monitor 40 , reference numeral 42 represents a network interface, reference numeral 44 represents a system bus for interconnecting devices 22 to 38 , and 42 .
The video board 38 and monitor 40 may be omitted for video transmission only.
The terminal 12 constructed as above transmits video signals via the network to a remote video reception terminal (monitor terminal) and receives a camera control signal from a remote monitor terminal to control the camera 16 .
FIG. 3 is a block diagram showing the outline structure of the video reception terminal (monitor terminal) 18 . Reference numeral 122 represents a CPU for controlling the entirety of the terminal 18 , reference numeral 124 represents a main storage, reference numeral 126 represents a removable external storage unit such as a floppy disk and a CD-ROM, reference numeral 128 represents a secondary storage unit such as a hard disk, reference numeral 130 represents a mouse as a pointing device, reference numeral 132 represents a keyboard, reference numeral 138 represents a video board for displaying images on the screen of a monitor 140 , reference numeral 142 represents a network interface, reference numeral 144 represents a compression decoder for expanding compressed video signals, and reference numeral 146 represents a system bus for interconnecting devices 122 to 132 , 138 , 142 , and 144 .
The video reception terminal 18 has the same structure as the video transmission terminal 12 shown in FIG. 2 excepting that it has no function of controlling the camera and receiving camera images, that it has the decoder 144 for expanding compressed video signals, and that it has different system software from that of the video transmission terminal 12 . Some or all of the video reception terminals 18 can transmit a camera control signal to any one or ones of the video transmission terminals 12 or to the terminals 12 permitted to control their cameras. The video transmission terminal 12 received the camera control signal controls its camera 16 in accordance with the contents of the camera control signal, and sends back the current status of the camera 16 . In accordance with the received status signal, the monitor terminal displays the current status of the camera on the monitor. At the same time, the monitor terminal receives video data transmitted from the video transmission terminal, expands it, and displays it in real time on the monitor screen.
FIG. 4 illustrates the software configuration of this embodiment. The video reception terminal (monitor terminal) 18 is installed with camera control client software 50 , video reception software 52 , and map management software 54 . The camera control client software 50 remotely controls the camera 16 via the network 10 and video transmission terminal 12 . The video reception software 52 expands compressed video data supplied from the video transmission terminal 12 . The map management software 54 displays a camera symbol representative of the current position and status of the camera 16 on a map, and also displays an operation panel for controlling the camera 16 . A set of above-described software is stored either at the video transmission terminal 12 or video reception terminal 18 in its main storage medium or secondary storage medium.
The video reception software 52 also manages all the cameras 16 via the network 10 and video transmission terminals 12 , and stores fixed information of each camera 16 and variable information thereof (e.g., a camera name, a host name of the computer connected to the camera, a camera status such as pan, tilt, and zoom, a controllable or uncontrollable state, a camera name under control, a camera name under display). Such fixed and variable information is also supplied to the camera control client software 50 and map management software 54 to change the display of the camera symbol or the like.
The video transmission terminal 12 is installed with camera control server software 56 and video transmission software 58 . The camera control server software 56 controls the camera 16 via the camera controller 14 in response to a request from the camera client software 50 , and notifies the requested terminal of the current status of the camera 16 . The video transmission software 58 compresses video data output from the camera 16 in a predetermined compression format and transmits it via the network 10 to the requested terminal.
FIG. 5 shows examples of the display contents of the monitor screen of the video reception terminal 18 . Reference numeral 60 represents a map window showing a layout of, for example, an office, a store, or a warehouse in which cameras 16 are installed. In this map window, a plurality of maps 60 a, 60 b, 60 c, and 60 d can be selectively displayed. The number of maps which can be displayed depends upon the performance of the system and is not limited to a particular number. Each map 60 a, 60 b, 60 c, 60 d is provided with a tag. By clicking the tag with a mouse pointer, the map with the clicked tag is displayed at the front of the map window. The map displayed at the front also displays camera icons (camera symbols) 62 a, 62 b, 62 c, and 62 d of the cameras installed at this map. Each camera icon 62 a, 62 b, 62 c, 62 d is displayed being directed toward the direction of the camera 16 .
Reference numeral 64 represents a video display window having a plurality of video display areas 66 a to 66 f. In this embodiment, six video display areas are used. Obviously the number of these areas is not limited to six. A trash-can icon 66 g is displayed on the video display window 64 in order to stop displaying a camera image. A use method of the trash-can icon 66 g will be later described.
The video display window 64 has two display modes, one for displaying all video display areas as shown in FIG. 5 and the other for displaying only one video image area as shown in FIG. 13 to watch the image in one video display area. The former is called a glance mode and the latter is called a watching mode. The watching mode is used when one image is viewed as a magnified image or it is viewed at high resolution. Switching between the glance mode and the watching mode will be later described.
Reference numeral 68 represents a camera control panel which is provided with buttons and the like for instructing the direction (pan/tilt), zoom, and the like of a designated camera, and in this embodiment, also with a camera power button 70 for instructing a power on/off of a designated camera.
For example, when the map 60 c is selected in the map window 60 and displayed at the front of the window, a map such as shown in FIG. 6 is displayed and camera icons 62 e and 62 f representing two cameras disposed in this map are also displayed.
The camera control of this embodiment will be detailed. If an image of a camera 16 is to be displayed, the camera icon of the camera 16 is selected in the map window 60 by moving the mouse 130 to one of the video display areas 66 a to 66 f in the video display window 64 and releasing the click button (so called drag-and-drop). Usually, one of the video display areas 66 a to 66 f not used is selected. However, if the video display area in use is selected, a warning is issued to the effect that the camera is to be changed, and a user is urged to select either “continue” or “stop”. The basic operations of these processes are already known in the field of this art.
FIG. 7 illustrates a drag-and-drop operation of the camera icon 62 c to the video display area 66 c. An image taken with the camera represented by the camera icon 62 c is displayed in the video display area 66 c. While the camera icon is dragged, the mouse cursor changes to a shape shown in FIG. 8 so that the user can recognize the dragging operation for displaying an image. The map management software 54 notifies the video reception software 52 of an ID of the camera represented by the camera icon, and the video reception software 52 checks from the ID the direction, name, and host name of the camera and notifies these pieces of information to the camera control client software 50 and map management software 54 .
Next, the operation of controlling a camera will be described. Of the video display areas 66 a to 66 c, as the video display area (e.g., 66 c ) in which the image taken with the camera is displayed by the above operations is single clicked with the mouse 130 , this designated camera enters a controllable state. At this time, a yellow frame is displayed on the video display area 66 c to notify the user of the camera controllable state, and the camera control panel 68 is automatically displayed.
In accordance with the information supplied from the camera reception software 52 , the camera control client software 50 accesses over the network the camera control server software 56 of the video transmission terminal 12 connected to the selected camera. Thereafter, the camera control client software 52 transmits over the network the camera control signal designated by the user operation to the camera control server software 56 . In accordance with the received camera control signal, the camera control server software 56 notifies the current status of the camera 16 to the camera control client software 52 . The camera control client software 52 notifies the current status to the map management software 54 .
The map management software 54 changes the direction of the camera icon so as to match the direction of the camera 16 , displays a scope 72 shown in FIG. 9 indicating that an image is under display, and displays a control pointer 74 in the scope 72 to be used for the control of pan/tilt and zoom. As described earlier, the map management software 54 is constantly notified by the video reception software 52 of variation information (particularly of pan/tilt information) of the camera 16 under display, and in accordance with this information, the direction of the camera icon 62 a to 62 f is changed so as to match the direction of the camera.
The camera control panel 68 may be used in common by all the video display areas 66 a to 66 f or may be provided for each of the video display areas. If a plurality of camera control panels 68 are provided, the video display areas 66 a to 66 f are given specific serial numbers which are given to the corresponding ones of the camera control panels 68 . In this manner, a system can be realized which has a correspondence between images and camera control panels 68 easy to understand. Instead of serial numbers, names of cameras may be displayed or different colors may be allocated to the video display areas 66 a to 66 f.
FIG. 10 is a flow chart illustrating the operation of turning off the power of any selected camera 16 . If the power of the selected camera is to be temporarily turned off, the camera icon of the camera whose power is turned off is selected and the camera power button 70 in the camera control panel 68 is pressed. The camera power button 70 is displayed in different colors and/or characters (e.g., “power off” or “power on”) in accordance with the state of the camera power. In response to the operation of the camera power button 70 , the camera control client software 52 notifies over the network 10 the camera power-off request to the camera control server software 56 of the video transmission terminal 12 connected to the corresponding camera 16 (S 1 ).
The camera control server software 56 causes the camera controller 14 via the I/O board 34 to turn off the power of the video camera 10 (S 2 ). The camera power button 70 changes its display shape to indicate that the power is in an off-state (S 3 ). In this manner, the user is notified that the camera power is in the off-state.
If the power is supplied again to the camera in the off-state, the camera icon is selected with the mouse 130 and thereafter the camera power button 70 is again pressed. In this case, a camera power-on request is issued to the camera control server software 56 to supply power to the corresponding video camera 16 . The color of the camera power button 70 is changed to indicate the power-on state.
In the above manner, the power supply to any camera can be controlled by the monitor terminal 18 to save power consumption.
In accordance with a video transmission request from the video reception software 52 , the video transmission software 58 transmits a camera image. More specifically, the video reception software 52 requests the video transmission software 58 of the video transmission terminal 12 connected to the selected camera over the network 10 to transmit video data of one frame. In response to this request, the video transmission software 58 compresses the video data of the latest frame supplied from the camera and divides it into packets which are then transmitted to the requested video reception software 52 . The video reception software 52 reconfigures the received packets to generate a frame, and expands the compressed frame to display it in the designated one of the video display areas 66 a to 66 f. Thereafter, the video reception software 52 issues again the video transmission request. By repeating these processes, the video reception terminal 18 receives the images at the remote camera over the network and displays them.
If the images of a plurality of cameras are displayed at the same time, the video transmission request is issued to the video display transmission software 58 of the video transmission terminal 12 connected to each camera, and the image is received and displayed. These operations are cyclically performed for the cameras.
Changing the display position of a received camera image can be performed also by the drag-and-drop operation. For example, as illustrated in FIG. 11, if the video display area 66 c is to be changed to the video display area 66 b, the mouse pointer is moved to the video display area 66 c. After the mouse is clicked and maintained in this state, the mouse pointer is moved to the video display area 66 c whereat the mouse button is released.
With the above operations, the video reception software 52 stops displaying an image in the first selected video display area (area 66 c in FIG. 11 ), and starts displaying the image in the next selected video display area (area 66 b in FIG. 11 ). During this operation, the network connection is not intercepted.
In order to watch an image in a particular video display area (e.g., area 66 a ) during the glance mode, this display area is double clicked with the mouse. Then, the video display window 64 is switched to the watching mode of watching the image. FIG. 13 shows the video display window in the watching mode. A window 80 is called a watching display window. Reference numeral 82 represents a mode switch button used for returning to the glance mode. Reference numerals 84 a, 84 b, 84 c, and 84 d represent cursors for controlling the direction of the camera to display an image in conformity with the camera direction.
In the watching mode, one image is displayed in a magnified scale. In this case, it is possible to select either a smooth motion display which gives a priority of a display speed (frame rate) or a high resolution display which gives a priority of an image quality by increasing the data amount per one frame. FIG. 14A shows an image quality setting window for setting the high resolution display. Reference numeral 90 represents a display speed priority button, and reference numeral 92 represents an image priority button. One of these buttons 90 and 92 can be selected at a time. The image quality setting window is displayed on the monitor upon instruction by the watching mode. When the display is selected in the image quality setting window, a corresponding image of the watching mode is displayed.
Next, the operation of the watching mode after the image quality priority button 92 is pressed will be detailed. First, the video reception software 52 notifies the video transmission software 58 of the corresponding video transmission terminal 12 of a high resolution request over the network 10 . Upon reception of this high resolution request, the video transmission software 58 switches the transmission image to the high resolution. The video reception software 52 receives the high resolution image and displays it in the watching display window 80 . In this case, since the high resolution image has a data amount larger than the standard resolution image, the display speed lowers in some cases.
As the mode switch button 82 is pressed or the watching display window 80 is double clicked with the mouse, the video display window 64 resumes the glance mode. The video reception software 52 notifies the video transmission software 52 of the corresponding video transmission terminal 12 of a standard resolution request over the network 10 . Upon reception of the standard resolution request, the video transmission software 58 changes the transmission image to the standard resolution.
Next, the operation of the watching mode after the display speed priority button 90 is pressed will be described. In this case, the video reception software 52 notifies nothing to the video transmission software 58 . The video reception software 52 magnifies the image transmitted at the standard resolution and displays it in the watching display window 80 . The operation of returning to the glance mode is the same as the case the image quality button 92 is selected.
In the mode selection, although the image resolution is controlled, an image compression ratio or an image transmission rate may be controlled.
Next, the operation of controlling a camera in the watching mode will be described. Similar to the glance mode, the motion of a camera can be controlled in the watching mode by using the camera control panel 68 . The camera can be controlled also by pressing the button of the mouse in the watching display window. As indicated by broken lines in FIG. 13, depending upon the position of the mouse cursor in one of the upper/lower and right/left areas in the watching display window 80 , the mouse cursor changes to one of the camera direction control cursors 84 a to 84 d. When the mouse button is pressed, the direction of the camera is changed to one of the upper/lower and right/left directions.
Although the video reception terminal does not display other images on the monitor during the watching mode, the communication with the corresponding video transmission terminals is maintained. As a result, when the watching mode is terminated, the monitor can be changed to the multi-image display state at high speed.
It is obvious that in response to a mode change instruction to the watching mode, communications with the other video transmission terminals may be intercepted to shift to the image quality priority mode or display speed priority mode. Alternatively, as shown in FIG. 14B, a communication keep button and a communication stop button may be provided in the image quality setting window in order to instruct, when the watching mode is designated, to keep or stop communications with the other video transmission terminals.
Therefore, in the watching mode, the designated terminal can be assigned a broad channel band so that an image of high resolution can be transmitted and an image of a high frame rate can be transmitted.
If the image display is to be terminated, the image displayed in the video display area is dragged and dropped in the trash-can icon 66 g. FIG. 12 illustrates an operation of stopping the display of an image in the video display area 66 c. The mouse pointer is moved to the video display area 66 c and the mouse button is pressed. In the state of the pressed mouse button, the mouse pointer is moved to the trash-can icon 66 g whereat pressing the mouse button is released.
In response to the above operations, the video reception software 54 stops issuing the video transmission request to the video transmission software 58 of the video transmission terminal connected to the camera which displays the image in the selected video display area (area 66 c in FIG. 12 ). Furthermore, the video reception software 54 notifies the image display termination to the camera control client software 50 and map management software 54 . In response to this notice, the camera control client software 50 disconnects the network connection to the camera control server software 56 of the corresponding video transmission terminal 12 to clear its video display area (area 66 c in FIG. 12 ). The map management software 54 erases the scope display of the camera icon (e.g., icon 62 c ) of the corresponding camera to update the map.
In this embodiment, the camera symbol in the map is dragged and dropped in the video display area to establish the network connection between the video reception and transmission terminals. The image display position can be changed by a drag-and-drop operation between the video display area in which a camera image is displayed and another optional video display area. An image display can be stopped by a drag-and-drop operation from the video display area in which a camera image is displayed to the display stop symbol. As above, it becomes very easy to start a camera image display, change a display position, and stop an image display. Obviously, images are not limited to only camera images, but other images may be used such as images generated from a storage medium such as a video tape.
<Second Embodiment>
FIG. 15 is a block diagram showing the outline structure of a video transmission terminal 112 having a switcher and a synthesizer connected thereto. Similar to the first embodiment, the video transmission terminal 112 is connected to a network 110 to which a plurality of video transmission and reception terminals are connected.
In the first example shown in FIG. 2, one video camera is connected to one video transmission terminal. In the second embodiment, four camera controllers 114 a to 114 d are connected to the switcher 101 and four video cameras 116 a to 116 d are connected to the synthesizer 102 .
The synthesizer 102 will be described. The synthesizer 102 synthesizes moving image analog signals supplied from the video cameras 116 a to 116 d, as indicated at 166 a in FIG. 16 . As indicated at 66 a in FIG. 17, an image of each video camera can be selectively displayed by sending a command from the video transmission terminal to the synthesizer 102 via the switcher 101 .
The switcher 101 will be described. As different from the structure shown in FIG. 2, the structure shown in FIG. 15 has four camera controllers connected to the switcher 101 . In order for the computer to control the video camera, the camera controllers 114 a to 114 d are required to be switched. The switcher 101 performs this function. As described before, as the command is sent to the synthesizer 102 , moving image signals from the video cameras can be selected or synthesized.
FIG. 18 is a block diagram showing the outline structure of the video reception terminal (monitor terminal) 118 . The video reception terminal has the same hardware structure as the first embodiment, but has different software.
FIG. 19 illustrates the software configuration of this embodiment. The video reception terminal (monitor terminal) 118 is installed with camera control client software 150 , video reception software 152 , and map management software 154 . The camera control client software 150 remotely controls the cameras 116 a to 116 d via the network 110 and video transmission terminals 112 . The video reception software 152 expands compressed video data supplied from the video transmission terminal 112 . The map management software 154 displays a camera symbol representative of the current position and status of each camera 116 a to 116 d on a map, and also displays an operation panel for controlling each camera 116 a to 116 d. Similar to FIG. 1, to the network 110 a plurality of video transmission terminals 112 - 1 to 112 -n and video reception terminals 118 -a to 118 -n are connected.
The video reception software 152 also manages all the cameras 116 via the network 110 and video transmission terminals 112 , and stores fixed information of each camera 116 and variable information thereof (e.g., a camera name, a host name of the computer connected to the camera, a camera status such as pan, tilt, and zoom, a controllable or uncontrollable state, a camera name under control, a camera name under display). Such fixed and variable information is also supplied to the camera control client software 150 and map management software 154 to change the display of the camera symbol or the like. A set of above-described software is stored either at the video transmission terminal 112 or video reception terminal 118 in its main storage medium or secondary storage medium.
The video transmission terminal 112 is installed with camera control server software 156 and video transmission software 158 . The camera control server software 156 controls the camera 116 via the camera controller 114 in response to a request from the camera client software 150 , and notifies the requested terminal of the current status of the camera 116 . The video transmission software 158 compresses video data output from the camera 116 in a predetermined compression format and transmits it via the network 110 to the requested terminal.
As shown in FIG. 15, for the control of the video cameras 116 a to 116 d via the switcher 101 , the camera control server software 156 supplies the switcher 101 with a command for selecting a video camera to be controlled, so that the switcher 101 is connected to the corresponding camera controller of the video camera. Thereafter, in response to a request from the camera control client software 150 , the video camera is controlled by the switcher 101 and camera controller 114 connected thereto.
FIG. 20 shows examples of the display contents of the monitor screen of the video reception terminal 118 . Like constituents to those shown in FIG. 5 are represented by identical reference numerals and the description thereof is omitted. Reference numeral 110 represents a single image display mode button. When this button is clicked, as indicated at 111 in FIG. 21, a new window is popped up and only the selected moving image is displayed. When the single image display mode button is clicked, a command for stopping image transmission is sent to the video transmission terminals other than the selected terminal, and a command for increasing a frame rate or raising a resolution is sent to the selected terminal in order to efficiently utilize the capacity of empty channels.
Whether the command for increasing a frame rate or raising a resolution is determined in accordance with initial setting made by a user. Obviously, with this initial setting, a balanced setting of both the frame rate and resolution may be set.
In FIG. 20, reference numeral 112 represents a four-image simultaneous display button, and reference numeral 113 represents a selective display button. These buttons are made valid only when the video transmission terminal is selected which is connected to the four video cameras via the synthesizer and switcher shown in FIG. 15 . Assuming that the image at 66 a in the video display area 64 is supplied from the video transmission terminal shown in FIG. 15, the four-image simultaneous display button 112 and selective display button 113 become valid when the image 66 a is selected by the mouse.
For example, if the lower right image among the four images displayed simultaneously as shown in FIG. 16 is clicked and thereafter the selective display button 113 is clicked, then the image shown in FIG. 17 is displayed. If the image 66 a shown in FIG. 17 is clicked and thereafter the four-image simultaneous display button 112 is clicked, the images shown in FIG. 16 are displayed.
If the selected tag 60 a to 60 d has a video transmission terminal which does not use the switcher and synthesizer, the buttons 112 and 113 are not displayed. A video transmission terminal having the switcher and synthesizer is discriminated from other terminals by exchanging the current status between the video transmission and reception terminals displayed when the map is switched.
Next, the single image display mode will be described. As one of the image display areas 66 a to 66 f is clicked with the mouse 130 and thereafter the single image display mode button 113 is clicked, the single image display window 111 shown in FIG. 22 is popped up and the selected image is displayed.
Next, consider the switching to the single image display mode from the state that four images are displayed from the video transmission terminal having four video cameras via the synthesizer and switcher shown in FIG. 15 . The images shown in FIGS. 16 and 17 are those images supplied from the video transmission terminal shown in FIG. 15 .
As the single image display mode button 110 is clicked while the images shown in FIG. 16 are displayed, the single image display window 111 shown in FIG. 23 is popped up. Since these images are supplied from the video transmission terminal having four video cameras via the synthesizer and switcher, the four-image simultaneous display button 112 a and selective display button 113 a are displayed in the single image display window 111 . In this case, if the lower right image shown in FIG. 23 is clicked with the mouse and thereafter the selective display button 113 a is clicked, the image shown in FIG. 22 is displayed.
Similar to switching to the single image display mode, the image shown in FIG. 22 has a good image quality because of the improved frame rate and resolution effected in response to the command.
If the single image display mode button 110 is clicked while the image shown in FIG. 17 is displayed, the single image display window 111 shown in FIG. 22 is popped up. Since this image is supplied from the video transmission terminal connected to four video camera via the synthesizer and switcher, the four-image simultaneous display button 112 a and selective display button 113 a are displayed in the single image display window 111 . In this case, as the four-image simultaneous display button 112 a is clicked with the mouse, four images shown in FIG. 23 are displayed at the same time.
In this embodiment, even in the single image display mode, images from the video transmission terminal connected to four video cameras via the synthesizer and switcher can be synthesized or selected. Therefore, image synthesis and selection can be easily performed by a user without confirming whether the operation mode is the single image display mode or the glance image display mode.
<Other Embodiments>
Programs realizing the structures and functions of the above embodiments may be stored in a storage medium. In this case, a method of realizing the above embodiments with such programs and the storage medium constitutes other embodiments of this invention.
Such a storage medium may be a floppy disk, a hard disk, an optical disk, a magnetooptical disk, a CD-ROM, a magnetic tape, a non-volatile memory card, and a ROM.
Other types of embodiments of this invention include not only for the case wherein the embodiment functions are realized by executing the program stored in the storage medium but also for the case wherein the programs are executed on an OS together with other application software and functions of other expansion boards. | A communication system easy to be operated upon as to the display method of images generated by image generating units of a plurality of communication terminals and as to the control of each image generating unit. The communication system has a reception unit for receiving images generated by image generating units of a plurality of communication terminals, an output unit for outputting a multi-image of images received by the reception unit to a display unit, a designation unit for designating an arbitrary image from the images constituting the multi-image, and a processing unit for controlling the output form of an image to be output to the display unit, the image being designated by the designation unit, if a designation operation by the designation unit is a first designation operation, and for setting the communication terminal as a control object, the communication terminal generating an image designated by the designation unit, if a designation operation by the designation unit is a second designation operation. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to UK Patent App. No. GB0909242.0, titled “Boiling Water Reactor” and filed May 29, 2009 by Abdulsalam Al-Mayahi and Mohammed Aljohani. The present application also claims priority to U.S. Provisional App. No. 61/237,681, titled “Combined Cycle Power Plant” and filed Aug. 28, 2009 by Mohammed S. Aljohani, P. M. V. Subbarao, Abdulsalam Al-Mayahi and R. Senthil Murugan. The referenced priority applications are hereby incorporated herein by reference in their entirety.
BACKGROUND
[0002] In a Rankine cycle operating in a condensing mode, a major portion of the heat in the cycle is rejected to the cooling water, which results in thermal pollution of the environment and a higher energy loss. In a multi-stage condensing turbine the last few stages of the turbine operate in a two phase region at low temperature leading to inefficient energy transfer in the low pressure (LP) turbine. When the condenser is working at vacuum pressure, air removal is mandatory; otherwise, the partial pressure of air increases the total pressure of the system and leads to a loss in power output and corrosion to various components. Due to a substantial increase in specific volume as the steam expands in the last few stages of a turbine, the size of the openings through which the steam passes must increase from stage to stage. Because of high volumetric flow rates, special care is needed for the appropriate choice of the LP turbine exhaust area and design.
[0003] A classic example of a power plant operating using the Rankine cycle is a boiling water reactor (BWR). A BWR is a nuclear reactor of light water developed by the General Electric Company in the mid 1950s, in which the normal very pure water is considered as a coolant and as a moderator for the reactor, water is boiling in the core of the reactor and producing steam. In BWR, the water which moves upward through the reactor core absorbs heat and acts as both moderator and coolant. Some of liquid water is converted to a steam. The steam-water mixture leaves the top of the core and enters a moisture separator where water droplets are removed before the steam is allowed to enter the steam line, and the steam line directs the steam to the main turbine, causing it to rotate the turbine generator, which generates electricity. The exhausted steam from turbine enters the condenser where it is condensed into water. The condensed water is pumped out of the condenser with a series of pumps, reheated and pumped back to the reactor.
[0004] A standard operating pressure for these boiling water reactors is about 70 bar at which pressure the water boils at about 285 degree Celsius. This operating temperature gives a Carnot efficiency of only 42% with a practical operating efficiency of around 32%, somewhat less than a pressurized water reactor (PWR), a nuclear reactor operated at higher pressure so the water (the working fluid) does not change state to water vapor.
[0005] The BWR is characterized by the two-phase flow (water and steam) in the top part of the reactor core. Light water as a working fluid converys heat away from the nuclear fuel. The liquid water in the region of the fuel elements also “thermalizes” neutrons, i.e., trims down their kinetic energy, which is needed to recover the probability of fission of fissile fuel. Fissile fuel material, such as the U-235 and Pu-239 isotopes, have large capture cross sections for thermal neutrons.
[0006] Feedwater enters reactor pressure vessel (RPV) inside the BWR through nozzles high on the vessel, well above the upper part of the nuclear fuel assemblies (these nuclear fuel assemblies constitute the “core”) but lower the water level. The feedwater is pumped into the RPV from the condensers located under the low pressure turbines and after going through feedwater heaters that raise its temperature with extraction steam from various turbine stages.
[0007] The feedwater enters into the downcomer section and combines with water coming down from the water separators. The feedwater subcools the saturated water that is recycled from the steam separators. The water is separated from the core by a tall shroud and flows down the downcomer section, which then goes through either jet pumps or internal recirculation pumps that provide additional pumping power (hydraulic head). The water now turns and moves up through the lower core plate into the nuclear core where the fuel elements heat the water. When the flow shifts out of the core through the upper core plate, about 12 to 15% of the flow by volume is saturated steam.
[0008] By heating, the core can generate a thermal head that assists the recirculation pumps in recirculating the water inside of the RPV. Without recirculation pumps a BWR can be designed and relies entirely on the thermal head to recirculate the water inside of the RPV. The forced recirculation head from the recirculation pumps is very useful in controlling power that is simply varied by increasing or decreasing the speed of the recirculation pumps.
[0009] The two phase fluid under saturation (water and steam) above the core enters the riser area which is at the top part of tall shroud where water separator is. The height of this section could be increased to enlarge the thermal natural recirculation pumping head. By spinning the two phase flow in cyclone separators, the steam is separated and goes up towards the steam dryer while the water remains behind and flows horizontally out into the downcomer region. In the downcomer region, it merges with the feedwater flow and the cycle repeats.
[0010] Reactor power is controlled by means of two methods, either by inserting or withdrawing control rods and/or by changing the water flow through the reactor core.
[0011] In all BWRs the ratio of the saturated liquid water to the saturated steam out from the separator is very high and lays on between 10-25 times, depends on the design features of the nuclear reactor and operating conditions. Accordingly, the high amount of saturated liquid within the reactor could be considered as an additional heat source if its sensible heat is taken and well utilized via proper process and apparatus such as running a power plant with high efficiency.
[0012] The Rankine cycle is the basic heating engine operating cycle used by most steam engines since the start of the industrial age, using heat sources starting with burning wood, oils, and gases, all the way to nuclear fission and fusion and beyond. Any heat source may be used. As with most heat engine cycles, the Rankine cycle is basically a four-stage process. Simply put, the working fluid (usually water) is pumped into a boiler. While the fluid is in the boiler, an external heat source heats the fluid, preferably superheats. The hot water vapor then expands to drive a turbine. Once past the turbine, the steam is condensed back into liquid and recycled back to the pump to start the cycle all over again. Pump, boiler, turbine and condenser are the four parts of a standard steam engine and represent each phase of the Rankine cycle.
[0013] The organic Rankine cycle (ORC) is a non-superheating thermodynamic cycle that uses an organic working fluid to generate electricity. The working fluid is heated to boiling, and the expanding vapor is used to drive a turbine. This turbine can be used to drive a generator to convert the work into electricity. The working-fluid vapor is condensed back into liquid and fed back through the system to do the work again. The organic chemicals used by an ORC include Freon and most of the other traditional refrigerants such as iso-pentane, CFCs, HFCs, butane, propane and ammonia.
[0014] Today, ORC systems are being evaluated to improve the working efficiency of distributed generation systems, to generate electricity from geothermal or solar natural heat sources, or to recover waste heat from industrial processes.
[0015] FIG. 1 illustrates the main parts of the BWR 100 or any basic power plant using the Rankine cycle. The BWR is a power plant or a heat engine for converting the thermal nuclear energy to mechanical power then generating electricity. The BWR uses a light normal water as a working fluid within a closed cycle. The nuclear reactor works as a source of steam (boiler 10 ) whereas the other three parts: turbine 30 , condenser 40 , and pump 50 are similar to those existing in any conventional Rankine cycle.
[0016] Referring to FIG. 1 in detail, steam and water are transferred from the lower part of a reactor core 10 to the upper part (a separator) 20 via line 11 . From the separator 20 the substantially dry steam in line 21 enters the turbine 30 to generate electrical power in generator 32 . The saturated liquid water leaves the separator 20 via line 22 and is mixed with condensed water coming from the condenser 40 . The steam at low pressure and temperature leaves the turbine 30 via line 31 and enters the condenser 40 , which is continuously cooled through cold stream 41 . Cold stream 41 could be any source of convenient coolant such as cooling tower water, seawater, river water, or dry air, etc., which leaves the condenser 40 at a higher temperature via line 42 . The condensate water leaves the condenser 40 via line 43 and is pumped by high pressure pump 50 , leaving the pump via line 51 to be merged with the saturated liquid water in line 22 . The mixed water of lines 51 and 22 is normally sub-cooled and enters the reactor core 10 via line 12 .
[0017] Kalina proposed a novel bottoming cycle for use in conventional steam and gas combined cycle systems. The Kalina cycle is a modified Rankine cycle, or rather a reversed absorption cycle utilizing ammonia-water working fluid and patented by Exergy Inc and A. Kalina. All Kalina cycles employ as working fluid a mixture of at least two working fluids, generally, though not exclusively, water and ammonia. Various published works describe advantages of the ammonia-water mixture for power generation using low grade heat. The multi-component working fluid, having a variable boiling temperature, generates less energy loss in the evaporator as the waste heat source has variable temperature in the evaporator as well. The ratio between those components is varied in different parts of the system to increase thermodynamic reversibility and therefore increase thermodynamic efficiency. There are multiple variants of Kalina cycle systems specifically applicable for different types of heat sources.
[0018] The Kalina cycle has proved theoretically and practically to have higher efficiency than other Rankine cycles such as organic Rankine cycle (ORC) but at the same time there are inherent limitations and higher initial costs.
[0019] The ammonia-water mixture used as the working fluid in the Kalina cycle has both varying boiling and condensing temperatures. Because of the variable boiling temperature, the temperature rise of the ammonia-water mixture, in a counter-flow heat exchanger, more closely follows the straight line temperature drop of a sensible heat source. The thermo-physical properties of the ammonia-water mixture can be altered by changing the ammonia concentration. Ammonia-water has thermo-physical properties that cause mixed fluid temperatures to increase or decrease without a change in the heat content.
[0020] In a typical Kalina cycle, a pressure-reducing valve (or throttle valve) is used to reduce the pressure of the lean liquid stream to a lower pressure downstream of the turbine. Then, the richer ammonia liquid solution downstream should be pumped back to the evaporator. The
[0021] There are numerous prior patents relating to variations of the Kalina cycle, including U.S. Pat. No. 4,346,561, U.S. Pat. No. 4,489,563, U.S. Pat. No. 4,548,043, U.S. Pat. No. 4,586,340, U.S. Pat. No. 4,732,005, U.S. Pat. No. 4,763,480, U.S. Pat. No. 4,899,545, U.S. Pat. No. 5,029,444, U.S. Pat. No. 5,095,708, U.S. Pat. No. 5,822,990, U.S. Pat. No. 5,950,433, U.S. Pat. No. 6,735,948, U.S. Pat. No. 6,769,256, U.S. Pat. No. 6,820,421, U.S. Pat. No. 6,829,895, U.S. Pat. No. 6,910,334, U.S. Pat. No. 6,923,000, U.S. Pat. No. 6,941,757 and U.S. Pat. No. 6,968,690.
[0022] FIG. 2 shows a simplified schematic for a conventional Kalina Cycle. The mixed working fluid, which in a water-ammonia system has a boiling point dependent on concentration, passes as a mixture of water and vapor from an evaporator 210 through line 213 to be partially separated in a separator stage 220 . The richer vapor component 221 passes to a turbine 230 for generation of electricity, while the leaner liquid component 222 passes via a recuperator heat exchanger 240 into line 241 and through a throttle valve 280 , which reduces its pressure, to rejoin the richer stream 245 downstream of the turbine 230 .
[0023] The recuperator 240 provides heat exchange with the condensate vapor and liquid stream 251 , which is first formed in the condenser 260 , pumped via high pressure pump 270 , and heated through heat exchanger 250 . The rejoined leaner and richer streams 245 pass through the heat exchanger 250 and from line 255 into a condenser 260 , where vapors condense to liquid in heat exchange with a cold stream 262 from cooling tower 263 , entering the cooling tower through line 264 and then sprayed into the cooling tower 263 . The liquid working fluid is pumped back to the evaporator 210 by the high pressure pump 270 pulling from line 264 into line 271 . Entering the evaporator 210 through line 242 , the working fluid at the evaporator 210 is evaporated by heat exchange with a heating source working fluid flowing from line 212 into evaporator 210 and then out line 211 .
[0024] The Mayahi cycle also uses ammonia-water as an organic working fluid, which is similar to the Rankine cycle but with a higher efficiency. International patent publication No WO/2009/037515 with publication date Mar. 26, 2009, relates to the Mayahi cycle.
[0025] Referring to FIG. 3 of the Mayahi cycle 300 , the working fluid mixture in an evaporator 310 is heated by a heat source working fluid via line 312 and then leaves the evaporator 310 at lower temperature via line 313 . Ammonia vapor is produced under pressure from an aqueous solution of ammonia within the evaporator 310 . The pressurized gas in line 314 drives a turbine 320 to produce electricity from a generator 322 coupled to the turbine. Ammonia gas at reduced pressure passes to absorber/condenser 330 in line 321 . The heat is rejected from condenser 330 through cooling stream 332 , which leaves at higher temperature via line 333 .
[0026] The key to the Mayahi cycle is the way in which the concentration of, and amounts of, ammonia solution in the condenser 330 and evaporator 310 are maintained. This is achieved in the power generation system of FIG. 3 by a first flow of solution from the higher pressure evaporator 310 to the condenser 330 , and by a second flow of solution from the condenser 330 to the evaporator 310 with aid of an auxiliary pump 340 . The solutions in the first and second flows are “exposed” to each other in two different apparatus, namely an energy recovery device (ERD), such as energy recovery turbine (ERT) 350 and a heat exchanger 360 . In the ERT 350 , an apparatus commonly employed in reverse osmosis desalination plants, the high pressure of one liquid is transferred to another. Here the high pressure of the flow from the evaporator 310 in line 362 is transferred to the lower pressure flow from the condenser 330 in line 341 , the lowered pressure flow from the evaporator 310 in line 352 passing to the condenser 330 in this example being employed for the spray via line 352 . Because the low pressure of the condenser flow has already been increased by pressure exchange in the ERT 350 , the pump 340 serves only an auxiliary purpose to increase the pressure of the stream in line 331 to higher pressure in line 351 , and so does not need to be a high pressure pump. Heat exchanger 360 exchanges heat between the evaporator flow 314 and the increased pressure flow from the condenser 351 before that flow enters the evaporator via line 361 .
[0027] Systems and methods for converting the thermal energy of low grade energy sources (low temperature heat sources) into electric power present a significant area of potential power generation. There is a necessity for a method and apparatus for increasing the efficiency of the conversion of such low temperature heat to electric power that improves the efficiency of the standard Rankine cycles, the Kalina cycle, or Mayahi cycle.
[0028] The present disclosure will include the existence of equivalent variations of specific embodiments, methods, and examples described herein. The present disclosure should therefore not be limited by the below described embodiments, methods, and examples, but by all embodiments and methods within the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The invention is hereinafter more particularly described by way of example only with reference to the accompanying drawings, in which:
[0030] FIG. 1 is a simplified schematic diagram of a conventional boiling water reactor or other Rankine cycle power plant.
[0031] FIG. 2 is a schematic diagram of the Kalina cycle.
[0032] FIG. 3 is a schematic diagram of the Mayahi cycle.
[0033] FIG. 4 is a similar diagram to FIG. 2 showing a modified Mayahi cycle in accordance with various embodiments of the present invention.
[0034] FIG. 5 is a similar diagram to FIG. 3 showing a modified Kalina cycle in accordance with various embodiments of the present invention.
[0035] FIG. 6 shows the better performance of combined Rankine-Kalina cycle over the conventional Rankine cycle.
DETAILED DESCRIPTION
[0036] Embodiments of the present invention present methods and systems that may be used and combined with a conventional power plant or a BWR to extract more power at higher efficiency in comparison with conventional power plants.
[0037] One embodiment of the present invention presents methods and systems that may be used and combined with a conventional power plant or a BWR to extract the sensible heat from the saturated water coming out from the separator inside the heat source or reactor core.
[0038] One embodiment of the present invention presents methods and systems that may be used to extract the sensible heat of a conventional power plant or a BWR through an ammonia-water cycle, such as conventional Kalina cycle, to generate electrical power at a high efficiency.
[0039] One embodiment of the present invention presents methods and systems that may be used to extract the sensible heat of a conventional power plant or a BWR through a modified Kalina cycle to generate electrical power at high efficiency in comparison with the conventional Kalina cycles.
[0040] One embodiment of the present invention presents methods and systems that may be used to extract the sensible heat of a conventional power plant or a BWR where thermal heat out in a sensible heat form is used as a heating source for the boiler of the conventional Mayahi cycle.
[0041] One embodiment of the present invention presents methods and systems that may be used to extract the sensible heat of a conventional power plant or a BWR where thermal heat out in a sensible heat form is used as a heating source for the boiler of a modified Mayahi cycle.
[0042] In prior art Kalina systems a pressure-reducing valve or throttle valve is essential to reduce the pressure of the lean liquid stream to the low pressure at the downstream side of the turbine. In addition, the condensed liquid working fluid from the condenser is pumped back to the evaporator.
[0043] In FIG. 4 , like reference numerals are employed to those of FIG. 2 . It will be noted that the throttle valve is omitted. Instead the high pressure lean liquid from the recuperator transfers its high pressure to the return liquid stream from the condenser to the evaporator by passing through an energy recovery turbine ERT before, with reduced pressure, rejoining the richer stream leaving the turbine. Because the pressure of the return stream has been raised as a result of this pressure transfer, only a small auxiliary pump may be required instead of the main high pressure pump.
[0044] A hydraulic Turbo Charger (Energy Recovery Turbine) is an energy exchanger for transferring hydraulic energy between two liquid streams, wherein one stream is at a comparatively higher pressure than the other, comprising a suitable related centrifugal mechanism. An example where an Energy Recovery Turbine (Turbo Charger) finds application is in the production of potable water using a reverse osmosis (RO) membrane process. In the RO process, a feed saline solution is pumped into a membrane unit at high pressure. The input saline solution is then divided by the membrane array into high concentration saline solution (brine) at high pressure and permeates water at low pressure. Whereas the high-pressure brine is no longer useful in this process as a fluid, the hydraulic or pressure energy that it contains is important. A hydraulic Energy Recovery Turbine is employed to recover the hydraulic energy (pressure energy) in the brine and transfer it to the feed saline solution. After transfer of the pressure energy in the brine flow, the brine is directed at low pressure to drain. For example, Fluid Equipment Development Company FEDCO and Pump Engineering Inc (PEI) are both producing those Energy Recovery Turbines and Turbo Chargers. Today, thousands of energy recovery devices are used in the desalination plants around the world to save energy, especially with seawater RO plants.
[0045] Thus it will be seen that, while, in the conventional Kalina cycle of FIG. 2 , internal pressure energy from the system is lost by using a pressure-reducing valve and external energy must be supplied to the system to pump the liquid solution back to evaporator, the cycle of FIG. 4 recovers the pressure from the lean stream and applies it to aid in pumping liquid back to the evaporator.
[0046] The described improvement can be employed in any of the variations of the Kalina cycle disclosed in the various patents cited above, with similar energy recovery devices eliminating the need both for a throttle valve in the lean stream and a high-pressure liquid pump. This improvement will increase the overall Kalina efficiency and reliability by eliminating the liquid pump for the return flow or replacing the previous high-pressure pump with a low-pressure auxiliary pump, which may also reduce cost.
[0047] Mayahi Cycle (Engine) efficiency, like any heat engine, is limited by the Carnot efficiency. The theoretical Carnot efficiency value of a cycle is equal to the temperature difference in degrees Kelvin between the high temperature in the boiler and low temperature in the condenser divided by the high temperature value of the boiler in Kelvin. Practically, a Mayahi Engine could have a higher actual efficiency than previous engines due to the saving of the pumping energy for the condensate back to the boiler. Wasting this energy cannot be avoided in other real cycles such as the Kalina cycle.
[0048] Thus, in accordance with the Mayahi cycle, a hydraulic Energy Recovery Turbine together with a heat exchanger are used in conjunction for an ammonia-water heat engine (power plant) instead of the conventional pump that is commonly used to pump the working fluid from the condenser (absorber) to the boiler (evaporator). The advantage of using a heat exchanger in conjunction with a hydraulic Turbo Charger (Energy Recovery Turbine) is that it minimizes the heat losses through the mixing process between the contents of the boiler (evaporator) and the condenser (absorber). This Mayahi cycle can utilize any available energy sources for heating the evaporator (boiler) with a temperature range from 100° C. to 500° C. and most preferably with a temperature range from 100° C. to 300° C. Cooling the absorber can be achieved by any available cooling source with a preferable temperature range from minus 20° C. to 50° C. Preferably, any available cooling source such as seawater, river water, cooling towers and air cooling can be employed.
[0049] Ammonia concentration in the Mayahi Engine may be varied from 10 to 90% in the liquid phase and the preferred concentration depends on the temperatures of heating and cooling. Generally, higher concentrations of ammonia mean higher working pressure on both the boiler and the absorber according to the thermodynamic equilibrium between concentration, pressure, and temperature.
[0050] FIG. 5 presents such modification to the conventional Mayahi cycle by adding an extra recuperator (heat exchanger) to take the heat from ammonia vapor that leaves the turbine at relatively high temperature. The heat is recovered and brought back into the system with minimal loses. As a result, Mayahi cycle efficiency can be increased. Though it is not shown in FIG. 5 , the modified Mayahi cycle may include a steam separator to separate low concentration ammonia liquid stream from the ammonia vapor outside the boiler.
[0051] Thus, in accordance with a first preferred embodiment of this aspect of the present invention, some of a sensible heat of the saturated water can be extracted from a BWR to run an ammonia-water cycle and generate power. Normally, BWR has a large amount of saturated water at a temperature of 285° C. and some of that sensible heat can be extracted. As a result of this invention, the BWR may operate at higher subcooling conditions that may require some fundamental modifications within the reactor core itself.
[0052] In a second preferred embodiment of this aspect of the present invention, the BWR could be redesigned and reengineered to allow for some of its saturated liquid at 285° C. coming down from the separator to leave the nuclear reactor cycle and operate an ammonia-water power plant.
[0053] In a third preferred embodiment of this aspect of the present invention, the BWR could be designed with new operating temperatures rather than the 285° C. to achieve maximum efficiency and optimum safe operating conditions. The new operating temperature could be ranged from 100-200° C., from 200-below 285° C., from above 285 to 300° C., and from 300 to 450° C.
[0054] In a fourth preferred embodiment of this aspect of the present invention, the ammonia water cycle is a conventional Kalina cycle based on the essence of the process in which the sensible heat from a BWR could be utilized to heat the boiler to make high pressure ammonia vapor which then can rotate the ammonia turbine and produce power.
[0055] In a fifth preferred embodiment of this aspect of the present invention, the Kalina cycle could be modified to enhance its efficiency by replacing the throttling valve with an energy recovery device. The modified Kalina cycle is not limited to be used with the BWR only however, as any power plant heat source could be used.
[0056] In a sixth preferred embodiment of invention, the modified Mayahi cycle could be combined with the BWR, utilizing the sensible heat to make the steam in the boiler and to rotate the turbine to generate power.
[0057] In a seventh preferred embodiment of this aspect of the present invention, the ammonia-water working fluid could replace the pure light water in the BWR and generate the ammonia vapor inside the BWR. In accordance with this embodiment, the BWR turbine will be used for ammonia and the nuclear reactor acts as a boiler in Mayahi or Kalina cycle.
[0058] Note that a combined cycle is easily formed by having line 12 of FIG. 1 feed line 212 of FIG. 2 or line 312 for FIG. 3 . The return line 211 of FIG. 2 or line 313 of FIG. 3 rejoins line 51 of FIG. 1 to form line 12 of FIG. 1 .
[0059] An ammonia-water cycle may provide a higher power output and more efficiency when using low grade steam or saturated steam coming out from the Rankine cycle between temperatures of 80-350° C. This may include an increase in the boiler pressure in the Rankine cycle and expansion close to the atmospheric or above atmospheric pressure with a bottoming ammonia-water cycle (Kalina Cycle).
[0060] A combined cycle may mitigate energy loss occurring in different major parts of the Rankine cycle such as the condenser, the evaporator, and the steam turbine. This combined cycle is more efficient than the stand-alone Rankine cycle due to effective utilization of low grade steam in ammonia-water cycle for efficient power production. The important benefit of this cycle is higher boiler pressure in the topping part where water as a working fluid and higher condenser pressure in the bottoming part where ammonia-water mixture as a working fluid.
[0061] In one embodiment, an energy recovery turbine is used in the Kalina Cycle in place of the throttle valve and drives the high-pressure liquid pump. Thus, there may be no need to use throttle valves and no extra motor to drive the high pressure liquid pumps in the bottoming cycle. According to another embodiment of the present invention, the usage of an energy recovery turbine in Kalina Cycle will eliminate the usage of a high-pressure pump or replacing it with a small auxiliary pump and that may enhance the system reliability and reduce the cost.
[0062] Embodiments of the present invention may be used with all types of Kalina cycles known in the art and provide a modified Kalina Cycle as a better alternative as a bottoming cycle. Since the condenser (such as 260 ) may be operating above the atmospheric pressure, air leakage and energy losses are less than those in a simple Rankine cycle. Moreover deaeration is not required in the ammonia-water cycle due to high pressure condensation. This cycle is more suitable for a low grade steam at inlet pressure of 0.20 MPa to 1 MPa and its corresponding saturation temperature of 120° C.-180° C. than the Rankine cycle. An ammonia-water cycle is identified as a bottoming cycle for Rankine cycle power plant. The following are the major reason to select ammonia-water in the bottoming cycle.
[0063] 1. Flexibility to reduce the fraction of ammonia in ammonia-water mixture helps to reduce heat transfer irreversibility in both evaporator and condenser when using low grade heat as a heat source for the bottoming cycle.
[0064] 2. The fraction of ammonia in the ammonia-water mixture restricts vacuum operation in the condenser. To operate the condenser above atmospheric pressure reduces energy loss in the LP turbine and condenser and also it minimizes the need of deaeration.
[0065] 3. Smaller turbine due to lower specific volume, higher efficiency due to less energy loss in the condenser.
[0066] Utilizing low grade steam below 0.20 MPa leads to vacuum operation in the heat exchanger. The heat source temperature to the bottoming cycle changes with time as output varies. Changing the composition in the Ammonia water mixture provides better optimum condition. The ability to change the mixture, and thus the thermodynamic properties of the working fluid offers an extra degree of control simply not possible in conventional Rankine power cycle.
[0000] Case Study for a Popular Steam Power Plant working on Regenerative Rankine Cycle:
[0067] Performance of stand-alone Rankine and combined cycle model is analyzed for design as well as off-design condition. An exclusive mathematical model and computer software is developed to optimize the performance and obtain best operational parameters of the combined cycle. Present model takes care of all the irreversibilities in the various part of the cycle and is more realistic analysis unlike many theoretical models.
[0068] A popular steam cycle design is used for present analysis. All the real parameters of existing popular steam power plant were used for the case study. FIG. 2 shows the variation of first law efficiency of popular steam power plant cycle as well as the new combined cycle configuration at different load condition. At design condition the cycle efficiency of combined cycle is 42.1989%.
[0069] FIG. 6 shows the comparisons between variations of efficiency at different load condition of a simple Rankine cycle and the combined cycle
[0070] The parameters of the Cycle configuration for the present case study with the optimum operating conditions for combined cycle model are listed in Table 1.
[0000]
TABLE 1
Results for combined cycle model
S
Node
P (bar)
T ° C.
X 1
h (kJ/kg)
M(kg/sec)
(kJ/kg K)
1
194
361.5
—
1776.0
1
3.939
2
192
361.5
—
2465
1
5.023
3
190.0
540
—
3378.1
1
6.333
4
3.0
133.5
—
2563.7
0.77
6.595
5
3.0
133.5
—
561.5
0.77
1.672
6
3.00
133.5
—
590.1
1
1.742
7
195.9
142.8
—
613.6
1.0
1.748
8
195.9
159.4
—
684.2
1.0
1.915
9
195.9
262.7
—
1146.9
1.0
2.872
10
50.0
345.9
—
3058.3
0.20
6.434
11
6.900
164.4
—
2692.4
0.03
6.552
12
3.00
133.5
—
686.0
0.23
1.978
13
46.49
48.65
0.890
150.2
1.425
0.732
14
45.60
123.5
0.890
1233.0
1.425
3.678
15
45.60
123.5
0.9692
1456.8
1.1410
4.215
16
6.917
32.2
0.9692
1216.7
1.1410
4.302
17
45.60
123.5
0.5716
333.19
0.2839
1.5715
18
45.16
36.71
0.5716
−64.62
0.2839
0.3864
19
6.917
37.66
0.5716
−64.62
0.2839
0.4020
20
6.9171
36.71
0.890
961.44
1.425
3.527
21
6.6698
30.33
0.890
887
1.425
3.296
22
6.4876
15
0.890
−9.9476
1.425
0.2270
23
4.7401
15.95
0.890
−3.0085
1.425
0.2290
24
4.6945
31.74
0.890
0.955
1.425
0.4792
1c
2
10
—
42
20.3
0.151
2c
2
25
—
104.9
20.3
0.296
[0071] Results in Table.2 depict that combined cycle shows better performance than stand alone Rankine steam cycle. During design condition the bottoming cycle which utilizes low grade heat from the Rankine cycle is 2.1% more efficient than Rankine cycle for same heat input.
[0000]
TABLE 2
Comparison of power output and efficiency
(for unit mass flow input of steam)
Power
Power
First Law
First law
output
output
efficiency of
efficiency of
from
from
Stand alone
combined
First Law Efficiency
Topping
bottoming
Rankine cycle
cycle
Topping
Bottoming
cycle
cycle
(%)
(%)
cycle
cycle
(kW)
(kW)
38.42
42.19
0.3026
0.17119
675.2
264.13
[0072] Similarly First law efficiency of combined cycle is 4% more than Rankine cycle for same heat input. The results in table depicts that there is 20% less energy loss in the condenser of a combined cycle when compared to stand alone Rankine cycle. Due to less energy loss with same cooling water inlet and outlet temperature the cooling water flow rate of combined cycle is 21.09% lesser than the stand alone Rankine cycle.
[0000]
TABLE 3
Comparison of condenser heat load and cooling water
flow rate (for unit mass flow input of steam)
Condenser
Condenser
Cooling
Cooling
heat load
heat load
Water flow rate in the
Water flow rate In the
for stand alone
for combined
condenser of a stand alone
condenser of a combined
Rankine cycle (kW)
cycle (kW)
Rankine cycle (m 3 /hr)
cycle (m 3 /hr)
1621
1287.8
1.5486
1.222
[0073] Energy loss in the condenser, irreversibility in the heat exchange process, especially in the evaporator, and efficiency losses due to expansion of low grade steam in the LP turbine are the three regions identified for performance loss in the Rankine cycle. The proposed combined cycle reduces these performance losses and improves the performance of the plant. Result shows that 4% improvement in cycle efficiency due to reduction of heat load in the boiler and 20% reduction of energy loss in the condenser and raise of 2.1% efficiency loss in the LP turbine. Consideration of the ammonia-water cycle as a bottoming cycle provides flexibility to raise the boiler pressure and to reduce energy loss in the condenser and ability to produce more power output using low grade steam.
Example Embodiments
[0074] In a first embodiment, the lower pressure part of the Rankine cycle is completely replaced with Kalina Cycle at an optimal temperature point. This optimal point may vary between 100 C to 450 C, depending on the parameters of the main Rankine cycle. This embodiment is referred to as a Combined Rankine-Kalina Cycle.
[0075] In a second embodiment, the lower pressure part of the Rankine cycle is completely replaced with an ammonia-water mixture power cycle at an optimal temperature point. This optimal point may vary between 100 C to 450 C, depending on the parameters of the main Rankine cycle. This embodiment is referred to as a Combined Steam-Ammonia Cycle.
[0076] In a third embodiment, the conventional bottoming cycle is modified by using an energy recovery turbine in place of throttle valve and replacing the extra-power-consuming high pressure pump by a small auxiliary pump. This will lead to further increase in efficiency of the combined cycle.
[0077] In a fourth embodiment, the conventional bottom cycle is modified by using a centrifugal absorber in place of condenser. This generates a lower pressure for the same ambient temperature of above mentioned combined cycle. In other words this bottoming cycle can work efficiently at high ambient temperatures. The size of the centrifugal absorber is lower than the conventional condenser.
[0078] In a fifth embodiment, the present combined cycle Rankine-Kalina cycle may be combined with any other high temperature power generation system, which can generate a flue gas with temperatures above 600 C (such as Solid Oxide Fuel Cell).
[0079] Although specific embodiments have been described hereinabove, it is recognized that one of ordinary skill in the art will understand the foregoing disclosure to include various modifications and alternative embodiments. For example, though the description focuses on a user interface having buttons for various functions, other forms of control are contemplated including rocker switches, toggles, pressure-sensitive areas on a programmable display, voice control, pointing devices, and those other mechanisms known in the art for interacting with electronic devices. It is intended that the following claims encompass such modifications and alternatives within their scope. | Modified Kalina and modified Mayahi cycle heat engines are disclosed. Improvements in efficiency may be gained through various changes to these cycles as well as combining these cycles with boiling water reactors and other Rankine cycle power plants. | 8 |
BACKGROUND
[0001] (a) Field
[0002] The subject matter disclosed generally relates to acoustic and filter closed-cell or partially closed-cell foams, and a method to reticulate them. More particularly, the subject matter disclosed generally relates to a method and an apparatus for reticulating foams using shock waves in a gaseous environment.
[0003] (b) Related Prior Art
[0004] A closed-cell foam production is generally cheaper and simpler than an open-cell foam production. However, the acoustic or filtering efficiency of closed-cell foams is poor compared to open-cell foams because it is very difficult for the acoustic waves or flow impinging the closed-cell foam to penetrate inside. A method to improve the acoustic and filtering behavior of closed-cell foam is to remove the membranes, or the impermeable partition, closing the cell pores (known as reticulations). Furthermore, it is known that materials with gradient in their microstructure, resulting in gradient in properties along their thickness or surface, can show a great increase of their acoustic and filtering behaviors.
[0005] Depending on the nature and properties of the reticulated products, such as pore size, flexibility, and the like, the materials with open-cells are of utility as filtering devices (air filters, water filters, microphone filters, drill motor filter, base for ceramic filters, . . . ), sound insulating devices (for cars, planes, trains, machinery, buildings), gas-liquid contacting devices, catalyst carriers, rug anchors, door mats, drain pads, sponges, mattresses, pillows, tire liners, and the like.
[0006] A great number of methods have been proposed to reticulate closed-cell foams, mainly to improve their filtration or acoustic properties.
[0007] For example, a well-known method to reticulate closed-cell foams is reticulation by shock waves of a material immersed in a liquid. In this method, the material to be treated is immersed in a liquid bath. Subsequently, a projectile is fired at high speed in the liquid, which produces a pressure wave used to treat the material. The pressure wave in the liquid may also be produced by a high speed piston, or by a string of explosives. However, by using this particular method, the material to be treated must be immersed in a liquid environment. This implies a large number of undesirable restrictions in the context of an industrial process. Moreover, by using this process, after treatment, the material must undergo a prolonged drying step. Also, the liquid environment requires some attention to avoid contamination, in addition to associated plumbing, and the like. These disadvantages may explain the fact that this method is not very popular.
[0008] Another well-know method to reticulate closed-cell foams is thermal reticulation. In this method, the material to be treated is placed in a chamber under high pressure and high temperature. A quick depressurization creates a flow of hot gas through the material and partially destroys the membranes of the closed-cells by melting. However, this method of thermal reticulation may not be applied in a continuous process. Also, the materials must be cooled after treatment. Moreover, by using this method, it is impossible to control the gradient of reticulations depending on the thickness or the surface (i.e., a pattern of reticulations) of the material to be treated.
[0009] Yet another well-know method to reticulate closed-cell foams is mechanical reticulation. According to this method, the material to be treated is cut into thin slices which are then compressed to a high compression ratio between rollers. This method is suitable for materials having a flexible skeleton (e.g., polyurethane). However, this method is not efficient enough because it does not significantly remove the closed-cell membranes.
[0010] Another well-know method to reticulate closed-cell foams is reticulation by gas. In this particular method, the material to be treated is placed in a tank filled with combustible gas. Ignition of the gas causes a controlled explosion that removes the thin membranes by the combined action of heat and blast wave caused by the explosion. However, this method cannot be applied in a continuous process. Moreover, the materials must be cooled after treatment. In addition, by using explosives, this method has a potential danger to security. Also, by using this method, it is impossible to control the gradient of reticulations depending on the thickness or the surface (i.e. a pattern of reticulations) of the material to be treated.
[0011] Still another well-know method to reticulate closed-cell foams is chemical reticulation. In this method, the material to be treated is placed in a chemical bath which reacts with the foam material to destroy membranes of the closed-cells. Chemical concentration, bath temperature and speed of passage of the material in the bath may be controlled accordingly. In another similar method, the chemical product is poured on the surface of the material to be treated for a capillary action. However, this method results in an expensive process, may use hazardous materials and Can produce a strong inhomogeneity of the surface and the volume of the treated material.
[0012] Another well-know method to reticulate closed-cell foams is the hydraulic reticulation. In this method, a water or air jet at high velocity is sent over the material to be treated. However, in this method, the structure of the material may be damaged and the liquid or air flow may be hardly homogeneous over a large surface area. Furthermore, the material must be dried after treatment in the case of the water jet reticulation.
[0013] The disadvantages of the foregoing methods for destroying cell membranes are varied. Many of such methods are efficient, yet may be uneconomical, slow, involve chemical products and/or immersion of the foam in a fluid, require drying or cooling the foam after treatment, and may be difficult to control. Furthermore, most of such methods do not allow controlling the reticulation rate along the foam thickness nor locally along the surface of the material and thus are unable to create a Functionally Graded Material (FGM).
[0014] For example, the gas explosion method described in U.S. Pat. No. 2,961,710 treats a foam block as a whole. The water shock treatment method described in U.S. Pat. No. 3,239,585 claims a uniform reticulation process but is unable to treat quickly and differently various surfaces of the foam strip since the foam strip has to be placed in a tank, must be immersed in fluid and treated as a whole by a single pressure wave. Like the gas reticulation, the so-called shock reticulation proposed in U.S. Pat. No. 3,239,585 cannot be practiced in a continuous manner. Only the chemical method could in theory create a gradient of properties but it is very difficult to control and potentially hazardous to use.
[0015] For these reasons and disadvantages, there is a serious need for a method and for an apparatus for reticulating foams using shock waves in a gaseous environment to improve their acoustic and filtering properties, which is economical, simple to process, practiced in a continuous manner, offers the potential to produce functionally graded materials and is easily implemented in the production or assembly line.
SUMMARY
[0016] Accordingly, it is an object of the present disclosure to provide a process to reticulate foams in a gaseous environment to improve the acoustic and filtering efficiency of the foams.
[0017] Another object of the present disclosure is to provide a process which can be applied in air (at room conditions).
[0018] Still another object of the present disclosure is to provide a process whereby the reticulation rate is controlled along thickness and/or surface for acoustic and filtering optimum performance.
[0019] A further object of the present disclosure is to provide a process for increasing the acoustic and filtering properties of foams which is economical, simple to process, practiced in a continuous manner and easily implemented in the production or assembly line.
[0020] An additional object of the present disclosure is to provide a process of increasing the softness, flexibility, and porosity of foams.
[0021] A still further object of the present disclosure is the provision of a process for reticulating closed-cell foams which requires no chemicals and is free of hazardous fumes and vapors.
[0022] Another object of the present disclosure is to provide an apparatus needed to reticulate foams using shock waves in a gas.
[0023] According to an embodiment, there is provided a process for improving the properties of closed-cell or partially closed cell foam, the process comprising: immersing the foam in a gaseous environment and impacting the foam with an energy impulse.
[0024] According to another embodiment, there is provided the process as described above, wherein the properties are acoustical properties.
[0025] According to another embodiment, there is provided the process as described above, wherein the properties are filtering properties.
[0026] According to another embodiment, there is provided the process as described above, wherein the energy impulse is a shock wave.
[0027] According to another embodiment, there is provided the process as described above, wherein the gaseous environment is air.
[0028] According to another embodiment, there is provided the process as described above, wherein the gaseous environment is ambient air.
[0029] According to another embodiment, there is provided the process as described above, wherein the gaseous environment is room condition air.
[0030] According to another embodiment, there is provided the process as described above, further comprising the step of: controlling the reticulation rate along the thickness of the foam.
[0031] According to another embodiment, there is provided the process as described above, wherein the energy impulse is applied uniformly on one side or on both sides of the foam to give a reticulation rate with symmetric properties along the thickness of the foam.
[0032] According to another embodiment, there is provided the process as described above, wherein the reticulation rate is controlled along the surface of the foam to create zones with different properties.
[0033] According to another embodiment, there is provided the process as described above, wherein the energy impulse is generated closely adjacent the foam.
[0034] According to another embodiment, there is provided the process as described above, further comprising the step of perforating the foam before the energy impulse occurred.
[0035] According to another embodiment, there is provided the process as described above, further comprising the step of qualifying the properties of the foam after the energy impulse occurred.
[0036] According to another embodiment, there is provided a shock wave generator for reticulating a material to be treated comprising: a primary section filled with a high pressure gas; a secondary section filled with a low pressure gas, peripherally extending from the primary section, the secondary section having an output; an impermeable partition impermeably separating the primary section and the secondary section; wherein when the impermeable partition is suddenly removed, a shock wave is generated and propagates in a gaseous environment in the output of the secondary section toward the material to be treated placed at the output of the secondary section.
[0037] According to another embodiment, there is provided the shock wave generator as described above, wherein the low pressure gas in an inert gas.
[0038] According to another embodiment, there is provided the shock wave generator as described above, further comprising an external supply pipe connected to the primary section for filling the primary section with the high pressure gas.
[0039] According to another embodiment, there is provided the shock wave generator as described above, wherein the impermeable partition comprises a breakable membrane.
[0040] According to another embodiment, there is provided the shock wave generator as described above, wherein the impermeable partition comprises a valve.
[0041] According to another embodiment, there is provided the shock wave generator as described above, wherein the high pressure gas comprises air, nitrogen, reactive gas or a combination thereof.
[0042] According to another embodiment, there is provided the shock wave generator as described above, wherein the high pressure gas comprises helium.
[0043] According to another embodiment, there is provided the shock wave generator as described above, wherein the low pressure gas comprises air.
[0044] According to another embodiment, there is provided the shock wave generator as described above, wherein the low pressure gas comprises argon.
[0045] According to another embodiment, there is provided the shock wave generator as described above, wherein the pressure of the high pressure gas is precisely controlled when the impermeable partition is suddenly removed for generating the shock wave to generate shock wave of a desired strength.
[0046] According to another embodiment, there is provided a foam reticulating system for treating a closed-cell or partially closed cell foam for increasing the acoustical or filtering properties of the foam, the system comprising: a conveyor for displacing the foam in a gaseous environment; a shock wave generator for impacting the foam with a shock wave travelling in the gaseous environment.
[0047] According to another embodiment, there is provided the foam reticulating system as described above, further comprising sensor device for qualifying the properties of the foam after impact from the shock wave.
[0048] According to another embodiment, there is provided the foam reticulating system as described above, further comprising a perforation device for perforating the foam prior to impact from the shock wave.
[0049] Features and advantages of the subject matter hereof will become more apparent in light of the following detailed description of selected embodiments, as illustrated in the accompanying figures. As will be realized, the subject matter disclosed and claimed is capable of modifications in various respects, all without departing from the scope of the claims. Accordingly, the drawings and the description are to be regarded as illustrative in nature and not as restrictive and the full scope of the subject matter is set forth in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Further features and advantages of the present disclosure will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
[0051] FIG. 1A is a cross-sectional schematic view of a shock wave generator in accordance with an embodiment;
[0052] FIG. 1B is a cross-sectional schematic view of a shock wave generator in accordance with another embodiment;
[0053] FIG. 2 is a cross-sectional schematic view of foam reticulating system for performing the process of reticulating materials using a shock wave in a gaseous environment;
[0054] FIG. 3A is a perspective schematic view of a foam reticulating system implementing the process of reticulating materials using a shock wave generator in accordance with another embodiment;
[0055] FIG. 3B is a perspective schematic view of a foam reticulating system implementing the process of reticulating materials using various shock wave generators in accordance with another embodiment;
[0056] FIG. 3C is a perspective schematic view of a foam reticulating system implementing the process of reticulating materials performing various shock wave treatments with one shock wave generator in accordance with another embodiment;
[0057] FIG. 3D is a cross-sectional schematic view of a foam reticulating system implementing a process of reticulating materials performing multiple shock wave treatments using multiple shock wave generators in accordance with another embodiment;
[0058] FIG. 4 is a graphic illustration of the foam sound absorption efficiency according to the frequency before and after treatment;
[0059] FIG. 5A is a photography showing a magnified view of a partially closed-cell foam;
[0060] FIG. 5B is a photography showing a magnified view of a partially closed-cell foam after shock treatment; the foam becomes open cells.
[0061] FIG. 6A is a schematic view of a foam reticulating system implementing a static process of reticulating materials using a shock wave in a gaseous environment in accordance with another embodiment;
[0062] FIG. 6B is a schematic view of a foam reticulating system implementing a continuous process of reticulating materials using a shock wave in a gaseous environment in accordance with another embodiment; and
[0063] FIG. 7 is a cross-sectional schematic view of a mechanical perforation machine for implementing a process of reticulating materials using a shock wave in a gaseous environment including a step of mechanically perforating the material before shock wave treatment, in accordance with another embodiment.
[0064] It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTION
[0065] In an embodiment there is disclosed a shock wave generator apparatus for reticulating materials, such as foams, using shock waves in a gaseous environment. The shock wave generator apparatus may improve numerous properties such as acoustical properties and filtering properties of a foam.
[0066] Referring now to the drawings, and more particularly to FIGS. 1A and 1B , there is shown a cross-sectional schematic view of shock wave generator 8 . The shock wave generator 8 includes a shock tube 10 , which is used to generate a controlled shock wave 16 in a gaseous medium. It is to be noted that the shock wave 16 may also be designated by any kind of energy impulses. One type of shock tube 10 uses two sections, a primary section 12 and a secondary section 20 , peripherally extending from the primary section 12 . The primary section 12 of the shock tube 10 is filled with a high pressure gas from an external supplier pipe 14 . As shown in FIG. 1B , the high pressure gas of the primary section 12 of the shock tube 10 may also be generated from an explosion or combustion within the primary section 12 , or by driving a piston 28 into this primary section 12 trough the valve 31 for generating compressed gas 29 . A great amount of energy is thus accumulated in this primary section 12 . The primary section 12 is separated from a secondary section 20 via an impermeable partition 24 , such as a breakable membrane or a valve 31 . On the other hand, the secondary section 20 is filled with low pressure gas. The low pressure gas may be air at room conditions. It is to be noted that the low pressure gas may be any other gas such as, without limitations, helium, argon, carbon dioxide or nitrogen. When the impermeable partition 24 is suddenly removed, a shock wave 16 is generated and propagates in the secondary section 20 toward surface of the material to be treated 22 placed at the output 18 of the secondary section 20 . A precise control of the pressure of the primary section 12 at rupture is used to generate shock waves 16 of desired strength.
[0067] In another embodiment (not shown), the shock tube 10 may use a single section filled completely or partially with detonable gas, or comprising a condensed phase explosive charge at the upstream end of the shock tube 10 . The initiation of a detonation in the gas or charge at the upstream end of the shock tube 10 causes the propagation of a shock wave 16 downstream of the shock tube 10 . The properties of this shock wave 16 may be controlled by changing the physical and chemical properties of the detonating medium.
[0068] Referring now to FIG. 2 , there is shown a foam reticulating system 100 comprising a shock wave generator 8 for performing the continuous process of reticulating materials, i.e., foams, using a shock wave 16 in a gaseous environment. In FIG. 2 , the continuous process foam reticulating system 100 includes a sensor device 50 , such as for example, without limitations, an in-situ acoustic emitter/receiver device, to control the quality of the shock treatment according to the shock wave 16 effect on the treated material 36 . The sensor device may also be, without limitations, a pressure transducer, a thermocouple, an ultrasound based emitter and receiver to measure key foam acoustic properties (porosity, tortuosity, flow resistivity), a microphone, an acoustic particle displacement sensor, an acoustic antenna, a video camera to infer mechanical properties and open cell content, a mechanical properties sensor device (laser vibrometer, accelerometer) and the like. It is to be noted that the sensor device 50 is positioned after the shock wave treatment in the continuous process foam reticulating system 100 . The sensor device 50 may also be fixed on the shock wave generator 8 to qualify the properties of the treated material 36 after the shock wave treatment occurs in the continuous process foam reticulating system 100 .
[0069] Criteria measured using the sensor device 50 may be, without limitations, the sound absorption coefficient and/or the airflow resistivity and/or mechanical stiffness. In the process of reticulating materials using a shock wave 16 in a gaseous environment, the material to be treated 22 , such as foams, may move in a flow direction represented by arrows 52 via the conveyor 26 and the rollers 34 . Indeed, the material to be treated 22 , by moving in the flow direction 52 , is treated by the shock wave 16 of the shock wave generator 8 to become the treated material 36 . It is to be noted that the material to be treated 22 may be foams of closed-cells or partially closed-cells. In the other hand, the treated material 36 may be foams of open-cells or partially open cells.
[0070] Different processes to reticulate the foam are illustrated in FIGS. 3A , 3 B, 3 C and 3 D. FIG. 3A presents a continuous process foam reticulating system 200 to treat a large surface of the material to be treated 22 using only one shock wave generator 8 . The surface of treated material 36 treated by the continuous process foam reticulating system 200 depends in this case on the size of the shock wave generator 8 and its produced shock wave 16 and it is thus limited. In the continuous process foam reticulating system 200 , the material to be treated 22 , such as foams, moves in a flow direction via the conveyor 26 .
[0071] Referring now to FIG. 3B , a larger surface with various shock treatments may be achieved by using various shock wave generators 8 in the continuous process foam reticulating system 300 . This configuration allows reticulating large surfaces of the material to be treated 22 and if needed have various reticulation rates (penetration rates) for different areas or a double porosity effect depending on the shock wave strength generated by each shock wave generators 8 and its shock wave 16 . In the continuous process foam reticulating system 300 , the material to be treated 22 , such as foams, moves in a flow direction via the conveyor 26 to be transformed in a treated material 36 . A movable shock wave generator 8 can reach equal performance compared to the aforementioned foam reticulating systems 200 and 300 involving various shock wave generators 8 as shown in FIG. 3C .
[0072] In the continuous process foam reticulating system of FIG. 3C , the single shock wave generator 8 moves between a first position AA and a second position BB to treat a large surface of the material to be treated 22 . Finally, if a symmetric reticulation along the material thickness is required, a shock treatment with equal strength can be applied on both faces of the material to be treated 22 . This can be done using the shock wave generator of FIG. 3A on both faces after reversing the material to be treated 22 or at the same time by using two shock wave generators 8 as shown in the continuous process foam reticulating system 500 of FIG. 3D . It is to be noted that the continuous processes foam reticulating system 200 , 300 , 400 and 500 may be mechanically continuous process foam reticulating systems or continuous process foam reticulating systems operated by an operator.
[0073] Foam properties before and after wave shock treatment. The shock wave has a considerable effect on the microstructure and thus on the non-acoustic properties of the foam. Table 1 shows these properties before and after wave shock treatment. It is shown that the wave shock has a real and important influence on the microstructure of the foam, which reduces the resistivity to the passage of air through the porous material and its tortuosity, slightly increasing its porosity and density because its thickness is slightly reduced.
[0000]
TABLE 1
Properties of material to be treated and treated material
Foam Properties
To be treated
Treated
Thickness (mm)
25.6
18.4
Density ρ (kg/m 3 )
8.12
11.3
Air Resistivity σ (Ns/m 4 )
385 000
18 600
Porosity
0.96
0.99
Tortuosity α ∞
3
1.3
Viscous length Λ (μm)
300
50
Thermal length Λ′(μm)
300
340
[0074] Referring now to FIG. 4 , as an example, a 1 inch-thick flexible Polyimide foam with partially closed-cell, available on the open market, was treated in accordance with the shock wave generator 8 . A standard impedance tube was used to measure the sound absorption coefficient before and after treatment. In this case, the aforementioned foam sample was treated on both faces to get symmetric reticulation properties. There is shown in FIG. 4 that the shock wave generator 8 and in accordance with the continuous process foam reticulating system 400 allows to substantially increasing the sound absorption efficiency. In particular, before treatment the absorption is poor and is only significant at mechanically controlled resonances, a behavior typical of partially closed cell foams. After reticulation, these resonances are eliminated and the absorption improved. The treated foam absorption coefficient is typical of an open cell foam and/or fibrous materials.
[0075] Referring now to FIG. 5A , there is shown a photography of a magnified view of a partially closed-cell foam, which may represent the material to be treated 22 . On the other hand, according to FIG. 5B , there is shown photography of open-cells foam, which may represent the treated material 36 . FIG. 5B clearly shows that the reticulation process eliminated the membranes closing the cells resulting in a more connected open pores, resulting in turn in low flow resistivity, less tortuous paths and better acoustic performance.
[0076] Referring now to FIG. 6A , there is shown a schematic view of a static process foam reticulating system 600 for reticulating materials using a shock wave 16 in a gaseous environment in accordance with another embodiment. As shown in FIG. 6A , the material to be treated 22 must be within the gas in which the shock wave 16 is generated. In this particular case, the enclosure 32 is used as an airtight tank if the gas is other than atmospheric air. In the case of atmospheric air, the enclosure 32 may be used as an acoustic barrier to protect the operator of the static process 600 from the shock wave 16 .
[0077] Referring now to FIG. 6B , there is shown a schematic view of a continuous process foam reticulating system 700 for reticulating materials using a shock wave 16 in a gaseous environment in accordance with another embodiment. In the latter case, the material to be treated 22 is fed to the shock wave generator so as to scan the entire surface. In this particular case, the enclosure 32 is used as an airtight tank if the gas is other than atmospheric air. In the case of atmospheric air, the enclosure 32 may be used as an acoustic barrier to protect the operator of the static process 600 from the shock wave 16 .
[0078] Referring now to FIG. 7 , there is shown a cross-sectional schematic view of the pre-perforation machine 800 in accordance with another embodiment. The pre-perforation machine 800 represents the additional step of perforating the material to be perforated 40 before the shock wave treatment. Indeed, in the case of a porous material having a highly resistive flexible structure, in which the shock wave penetrates with difficulties, it is possible to perforate in advance the material and thereby facilitate the penetration of the shock wave. As a non-limitative example, in the pre-perforation machine 800 of FIG. 7 , the material to be perforated 40 could pass between two perforation rollers 38 having picks 44 randomly distributed on their surface. It is to be noted that the example pre-perforation machine 800 may include one or a plurality of perforation rollers 38 .
[0079] Additionally, the perforation rollers 38 may be made, without limitations, of a metallic material, or of any suitable material which have properties to allow perforation of the material to be perforated 40 . The perforated material 42 is then ready to be treated. Instead of using perforation rollers, the pre-perforation machine 800 may operate, for example, using high-pressure water jets, lasers or other similar devices.
[0080] Finally, it is possible to integrate to the continuous process foam reticulating system 100 of reticulating materials using a shock wave 16 in a gaseous environment a foam reticulation quality control device, such as an acoustic device, for example (see FIG. 2 ). This control system can be the sensor device 50 and would measure during treatment or immediately after treatment the acoustic performance of the treated material 36 . In the where the sensor device 50 is an acoustic device, the sensor device 50 can use the shock wave 16 of the shock wave treatment as a source or generate its own noise with a secondary audio source (i.e., speaker). The control sensors, which allow the acoustic properties measurement (e.g., absorption coefficient), can be microphones or other measurement probes.
[0081] The present invention will be more readily understood by referring to the following, examples which are given to illustrate the invention rather than to limit its scope.
[0082] While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure. | The present document describes a method and apparatus to rapidly reticulate closed-cell or partially closed-cell foams. The method involves the propagation of an energy impulse inside the foam; the energy impulse can be a shock wave. The energy impulse is generated in the same gaseous environment in which the foam is immersed, preferentially air in room condition. The energy impulse destroys the membranes closing the foam cells without disintegrating the frame's structure. In particular, the method rapidly improves the acoustic and filtering behavior of the foams. | 8 |
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/542,072, which was filed on Oct. 3, 2006, now U.S. Pat. No. 7,306,353, which is a continuation of U.S. application Ser. No. 10/789,357, which was filed on Feb. 27, 2004, now U.S. Pat. No. 7,114,831, which is a continuation of U.S. application Ser. No. 09/693,548, which was filed on Oct. 19, 2000, now U.S. Pat. No. 6,712,486, which claims the benefit of U.S. Provisional Patent Application Nos. 60/160,480, which was filed on Oct. 19, 1999 and 60/200,351, which was filed on Apr. 27, 2000. The entirety of each of these related applications is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the field of light emitting diode (LED) lighting devices and more particularly in the field of an LED lighting module having heat transfer properties that improve the efficiency and performance of LEDs.
2. Description of the Related Art
Light emitting diodes (LEDs) are currently used for a variety of applications. The compactness, efficiency and long life of LEDs is particularly desirable and makes LEDs well suited for many applications. However, a limitation of LEDs is that they typically cannot maintain a long-term brightness that is acceptable for middle to large-scale illumination applications. Instead, more traditional incandescent or gas-filled light bulbs are often used.
An increase of the electrical current supplied to an LED generally increases the brightness of the light emitted by the LED. However, increased current also increases the junction temperature of the LED. Increased juncture temperature may reduce the efficiency and the lifetime of the LED. For example, it has been noted that for every 10° C. increase in temperature, silicone and gallium arsenide lifetime drops by a factor of 2.5-3. LEDs are often constructed of semiconductor materials that share many similar properties with silicone and gallium arsenide.
SUMMARY OF THE INVENTION
Accordingly, there is a need in the art for an LED lighting apparatus having heat removal properties that allow an LED on the apparatus to operate at relatively high current levels without increasing the juncture temperature of the LED beyond desired levels.
In accordance with an aspect of the present invention, an LED module is provided for mounting on a heat conducting surface that is substantially larger than the module. The module comprises a plurality of LED packages and a circuit board. Each LED package has an LED and at least one lead. The circuit board comprises a thin dielectric sheet and a plurality of electrically-conductive contacts on a first side of the dielectric sheet. Each of the contacts is configured to mount a lead of an LED package such that the LEDs are connected in series. A heat conductive plate is disposed on a second side of the dielectric sheet. The plate has a first side which is in thermal communication with the contacts through the dielectric sheet. The first side of the plate has a surface area substantially larger than a contact area between the contacts and the dielectric sheet. The plate has a second side adapted to provide thermal contact with the heat conducting surface. In this manner, heat is transferred from the module to the heat conducting surface.
In accordance with another aspect of the present invention, a modular lighting apparatus is provided for conducting heat away from a light source of the apparatus. The apparatus comprises a plurality of LEDs and a circuit board. The circuit board has a main body and a plurality of electrically conductive contacts. Each of the LEDs electrically communicates with at least one of the contacts in a manner so that the LEDs are configured in a series array. Each of the LEDs electrically communicates with corresponding contacts at an attachment area defined on each contact. An overall surface of the contact is substantially larger than the attachment area. The plurality of contacts are arranged adjacent a first side of the main body and are in thermal communication with the first side of the main body. The main body electrically insulates the plurality of contacts relative to one another.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an LED module having features in accordance with the present invention.
FIG. 2 is a schematic side view of a typical pre-packaged LED lamp.
FIG. 3 is a top plan view of the LED module of FIG. 1 .
FIG. 4 is a side plan view of the apparatus of FIG. 3 .
FIG. 5 is a close-up side view of the apparatus of FIG. 3 mounted on a heat conductive member.
FIG. 6 is another sectional side view of the apparatus of FIG. 3 mounted onto a heat conductive flat surface.
FIG. 7 is a side plan view of an LED module having features in accordance with another embodiment of the present invention.
FIG. 8 is a side plan view of another LED module having features in accordance with yet another embodiment of the present invention.
FIG. 9 is a perspective view of an illumination apparatus having features in accordance with the present invention.
FIG. 10 is a side view of the apparatus of FIG. 9 .
FIG. 11 is a bottom view of the apparatus of FIG. 9 .
FIG. 12 is a top view of the apparatus of FIG. 9 .
FIG. 13 is a schematic view of the apparatus of FIG. 9 mounted on a theater seat row end.
FIG. 14 is a side view of the apparatus of FIG. 13 showing the mounting orientation.
FIG. 15 is a side view of a mounting barb.
FIG. 16 is a front plan view of the illumination apparatus of FIG. 9 .
FIG. 17 is a cutaway side plan view of the apparatus of FIG. 20 .
FIG. 18 is a schematic plan view of a heat sink base plate.
FIG. 19 is a close-up side sectional view of an LED module mounted on a mount tab of a base plate.
FIG. 20 is a plan view of a lens for use with the apparatus of FIG. 9 .
FIG. 21 is a perspective view of a channel illumination apparatus incorporating LED modules having features in accordance with the present invention.
FIG. 22 is a close-up side view of an LED module mounted on a mount tab.
FIG. 23 is a partial view of a wall of the apparatus of FIG. 21 , taken along line 23 - 23 .
FIG. 24 is a top view of an LED module mounted to a wall of the apparatus of FIG. 21 .
FIG. 25 is a top view of an alternative embodiment of an LED module mounted to a wall of the apparatus of FIG. 21 .
FIG. 26A is a side view of an alternative embodiment of a lighting module being mounted onto a channel illumination apparatus wall member.
FIG. 26B shows the apparatus of the arrangement of FIG. 26A with the lighting module installed.
FIG. 26C shows the arrangement of FIG. 26B with a lens installed on the wall member.
FIG. 26D shows a side view of an alternative embodiment of a lighting module installed on a channel illumination apparatus wall member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference first to FIG. 1 , an embodiment of a light-emitting diode (LED) lighting module 30 is disclosed. In the illustrated embodiment, the LED module 30 includes five pre-packaged LEDs 32 arranged on one side of the module 30 . It is to be understood, however, that LED modules having features in accordance with the present invention can be constructed having any number of LEDs 32 mounted in any desired configuration.
With next reference to FIG. 2 , a typical pre-packaged LED 32 includes a diode chip 34 encased within a resin body 36 . The body 36 typically has a focusing lens portion 38 . A negative lead 40 connects to an anode side 42 of the diode chip 34 and a positive lead 44 connects to a cathode side 46 of the diode chip 34 . The positive lead 44 preferably includes a reflector portion 48 to help direct light from the diode 34 to the lens portion 38 .
With next reference to FIGS. 1-5 , the LED module 30 preferably comprises the five pre-packaged LED lamps 32 mounted in a linear array on a circuit board 50 and electrically connected in series. The illustrated embodiment employs pre-packaged aluminum indium gallium phosphide (AlInGaP) LED lamps 32 such as model HLMT-PL00, which is available from Hewlett Packard. In the illustrated embodiment, each of the pre-packaged LEDs is substantially identical so that they emit the same color of light. It is to be understood, however, that nonidentical LEDs may be used to achieve certain desired lighting effects.
The illustrated circuit board 50 preferably is about 0.05 inches thick, 1 inch long and 0.5 inch wide. It includes three layers: a copper contact layer 52 , an epoxy dielectric layer 54 and an aluminum main body layer 56 . The copper contact layer 52 is made up of a series of six elongate and generally parallel flat copper plates 60 that are adapted to attach to the leads 40 , 44 of the LEDs 32 . Each of the copper contacts 60 is electrically insulated from the other copper contacts 60 by the dielectric layer 54 . Preferably, the copper contacts 60 are substantially coplanar.
The pre-packaged LEDs 32 are attached to one side of the circuit board 50 , with the body portion 36 of each LED generally abutting a side of the circuit board 50 . The LED lens portion 38 is thus pointed outwardly so as to direct light in a direction substantially coplanar with the circuit board 50 . The LED leads 40 , 44 are soldered onto the contacts 60 in order to create a series array of LEDs. Excess material from the leads of the individual pre-packaged LED lamps may be removed, if desired. Each of the contacts 60 , except for the first and last contact 62 , 64 , have both a negative lead 40 and a positive lead 44 attached thereto. One of the first and last contacts 62 , 64 has only a negative lead 40 attached thereto; the other has only a positive lead 44 attached thereto.
A bonding area of the contacts accommodates the leads 40 , 44 , which are preferably bonded to the contact 60 with solder 68 ; however, each contact 60 preferably has a surface area much larger than is required for adequate bonding in the bonding area 66 . The enlarged contact surface area allows each contact 60 to operate as a heat sink, efficiently absorbing heat from the LED leads 40 , 44 . To maximize this role, the contacts 60 are shaped to be as large as possible while still fitting upon the circuit board 50 .
The dielectric layer 54 preferably has strong electrical insulation properties but also relatively high heat conductance properties. In the illustrated embodiment, the layer 54 is preferably as thin as practicable. For example in the illustrated embodiment, the dielectric layer 54 comprises a layer of Thermagon® epoxy about 0.002 inches thick.
It is to be understood that various materials and thicknesses can be used for the dielectric layer 54 . Generally, the lower the thermal conductivity of the material used for the dielectric layer, the thinner that dielectric layer should be in order to maximize heat transfer properties of the module. For example, in the illustrated embodiment, the layer of epoxy is very thin. Certain ceramic materials, such as beryllium oxide and aluminum nitride, are electrically non-conductive but highly thermally conductive. When the dielectric layer is constructed of such materials, it is not as crucial for the dielectric layer to be so very thin, because of the high thermal conductivity of the material.
In the illustrated embodiment, the main body 56 makes up the bulk of the thickness of the circuit board 50 and preferably comprises a flat aluminum plate. As with each of the individual contacts 60 , the main body 56 functions as a heat conduit, absorbing heat from the contacts 60 through the dielectric layer 54 to conduct heat away from the LEDs 32 . However, rather than just absorbing heat from a single LED 32 , the main body 56 acts as a common heat conduit, absorbing heat from all of the contacts 60 . As such, in the illustrated embodiment, the surface area of the main body 56 is about the same as the combined surface area of all of the individual contacts 60 . The main body 56 can be significantly larger than shown in the illustrated embodiment, but its relatively compact shape is preferable in order to increase versatility when mounting the light module 30 . Additionally, the main body 56 is relatively rigid and provides structural support for the lighting module 30 .
In the illustrated embodiment, aluminum has been chosen for its high thermal conductance properties and ease of manufacture. It is to be understood, however, that any material having advantageous thermal conductance properties, such as having thermal conductivity greater than about 100 watts per meter per Kelvin (W/m-K), would be acceptable.
A pair of holes 70 are preferably formed through the circuit board 50 and are adapted to accommodate a pair of aluminum pop rivets 72 . The pop rivets 72 hold the circuit board 50 securely onto a heat conductive mount member 76 . The mount member 76 functions as or communicates with a heat sink. Thus, heat from the LEDs 32 is conducted with relatively little resistance through the module 30 to the attached heat sink 76 so that the junction temperature of the diode chip 34 within the LED 32 does not exceed a maximum desired level.
With reference again to FIGS. 3 and 5 , a power supply wire 78 is attached across the first and last contacts 62 , 64 of the circuit board 50 so that electrical current is provided to the series-connected LEDs 32 . The power supply is preferably a 12-volt system and may be AC, DC or any other suitable power supply. A 12-volt AC system may be fully rectified.
The small size of the LED module 30 provides versatility so that modules can be mounted at various places and in various configurations. For instance, some applications will include only a single module for a particular lighting application, while other lighting applications will employ a plurality of modules electrically connected in parallel relative to each other.
It is also to be understood that any number of LEDs can be included in one module. For example, some modules may use two LEDs, while other modules may use 10 or more LEDs. One manner of determining the number of LEDs to include in a single module is to first determine the desired operating voltage of a single LED of the module and also the voltage of the power supply. The number of LEDs desired for the module is then roughly equal to the voltage of the power supply divided by the operating voltage of each of the LEDs.
The present invention rapidly conducts heat away from the diode chip 34 of each LED 32 so as to permit the LEDs 32 to be operated in regimes that exceed normal operating parameters of the pre-packaged LEDs 32 . In particular, the heat sinks allow the LED circuit to be driven in a continuous, non-pulsed manner at a higher long-term electrical current than is possible for typical LED mounting configurations. This operating current is substantially greater than manufacturer-recommended maximums. The optical emission of the LEDs at the higher current is also markedly greater than at manufacturer-suggested maximum currents.
The heat transfer arrangement of the LED modules 30 is especially advantageous for pre-packaged LEDs 32 having relatively small packaging and for single-diode LED lamps. For instance, the HLMT-PL00 model LED lamps used in the illustrated embodiment employ only a single diode, but since heat can be drawn efficiently from that single diode through the leads and circuit board and into the heat sink, the diode can be run at a higher current than such LEDs are traditionally operated. At such a current, the single-diode LED shines brighter than LED lamps that employ two or more diodes and which are brighter than a single-diode lamp during traditional operation. Of course, pre-packaged LED lamps having multiple diodes can also be employed with the present invention. It is also to be understood that the relatively small packaging of the model HLMT-PL00 lamps aids in heat transfer by allowing the heat sink to be attached to the leads closer to the diode chip.
With next reference to FIG. 5 , a first reflective layer 80 is preferably attached immediately on top of the contacts 60 of the circuit board 50 and is held in position by the rivets 72 . The first reflector 80 preferably extends outwardly beyond the LEDs 32 . The reflective material preferably comprises an electrically non-conductive film such as visible mirror film available from 3M. A second reflective layer 82 is preferably attached to the mount member 76 at a point immediately adjacent the LED lamps 32 . The second strip 82 is preferably bonded to the mount surface 76 using adhesive in a manner known in the art.
With reference also to FIG. 6 , the first reflective strip 80 is preferably bent so as to form a convex reflective trough about the LEDs 32 . The convex trough is adapted to direct light rays emitted by the LEDs 32 outward with a minimum of reflections between the reflector strips 80 , 82 . Additionally, light from the LEDs is limited to being directed in a specified general direction by the reflecting films 80 , 82 . As also shown in FIG. 6 , the circuit board 50 can be mounted directly to any mount surface 76 .
In another embodiment, the aluminum main body portion 56 may be of reduced thickness or may be formed of a softer metal so that the module 30 can be partially deformed by a user. In this manner, the module 30 can be adjusted to fit onto various surfaces, whether they are flat or curved. By being able to adjust the fit of the module to the surface, the shared contact surface between the main body and the adjacent heat sink is maximized, improving heat transfer properties. Additional embodiments can use fasteners other than rivets to hold the module into place on the mount surface/heat sink material. These additional fasteners can include any known fastening means such as welding, heat conductive adhesives, and the like.
As discussed above, a number of materials may be used for the circuit board portion of the LED module. With specific reference to FIG. 7 , another embodiment of an LED module 86 comprises a series of elongate, flat contacts 88 similar to those described above with reference to FIG. 3 . The contacts 88 are mounted directly onto the main body portion 89 . The main body 89 comprises a rigid, substantially flat ceramic plate. The ceramic plate makes up the bulk of the circuit board and provides structural support for the contacts 88 . Also, the ceramic plate has a surface area about the same as the combined surface area of the contacts. In this manner, the plate is large enough to provide structural support for the contacts 88 and conduct heat away from each of the contacts 88 , but is small enough to allow the module 86 to be relatively small and easy to work with. The ceramic plate 89 is preferably electrically non-conductive but has high heat conductivity. Thus, the contacts 88 are electrically insulated relative to each other, but heat from the contacts 88 is readily transferred to the ceramic plate 89 and into an adjoining heat sink.
With next reference to FIG. 8 , another embodiment of an LED lighting module 90 is shown. The LED module 90 comprises a circuit board 92 having features substantially similar to the circuit board 50 described above with reference to FIG. 3 . The diode portion 94 of the LED 96 is mounted substantially directly onto the contacts 60 of the lighting module 90 . In this manner, any thermal resistance from leads of pre-packaged LEDs is eliminated by transferring heat directly from the diode 94 onto each heat sink contact 60 , from which the heat is conducted to the main body 56 and then out of the module 90 . In this configuration, heat transfer properties are yet further improved.
As discussed above, an LED module having features as described above can be used in many applications such as, for example, indoor and outdoor decorative lighting, commercial lighting, spot lighting, and even room lighting. With next reference to FIGS. 9-12 , a self-contained lighting apparatus 100 incorporates an LED module 30 and can be used in many such applications. In the illustrated embodiment, the lighting apparatus 100 is adapted to be installed on the side of a row of theater seats 102 , as shown in FIG. 13 , and is adapted to illuminate an aisle 104 next to the theater seats 102 .
The self-contained lighting apparatus 100 comprises a base plate 106 , a housing 108 , and an LED module 30 arranged within the housing 108 . As shown in FIGS. 9 , 10 and 13 , the base plate 106 is preferably substantially circular and has a diameter of about 5.75 inches. The base plate 106 is preferably formed of 1/16 th inch thick aluminum sheet. As described in more detail below, the plate functions as a heat sink to absorb and dissipate heat from the LED module. As such, the base plate 106 is preferably formed as large as is practicable, given aesthetic and installation concerns.
As discussed above, the lighting apparatus 100 is especially adapted to be mounted on an end panel 110 of a row of theater chairs 102 in order to illuminate an adjacent aisle 104 . As shown in FIGS. 13 and 14 , the base plate 106 is preferably installed in a vertical orientation. Such vertical orientation aids conductive heat transfer from the base plate 106 to the environment.
The base plate 106 includes three holes 112 adapted to facilitate mounting. A ratcheting barb 116 (see FIG. 15 ) secures the plate 106 to the panel 110 . The barb 116 has an elongate main body 118 having a plurality of biased ribs 120 and terminating at a domed top 122 .
To mount the apparatus on the end panel 110 , a hole is first formed in the end panel surface on which the apparatus is to be mounted. The base plate holes 112 are aligned with mount surface holes and the barbs 116 are inserted through the base plate 106 into the holes. The ribs 120 prevent the barbs 116 from being drawn out of the holes once inserted. Thus, the apparatus is securely held in place and cannot be easily removed. The barbs 116 are especially advantageous because they enable the device to be mounted on various surfaces. For example, the barbs will securely mount the illumination apparatus on wooden or fabric surfaces.
With reference next to FIGS. 16-19 , a mount tab 130 is provided as an integral part of the base plate 106 . The mounting tab 130 is adapted to receive an LED module 30 mounted thereon. The tab 130 is preferably plastically deformed along a hinge line 132 to an angle θ between about 20-45° relative to the main body 134 of the base plate 106 . More preferably, the mounting tab 130 is bent at an angle θ of about 33°. The inclusion of the tab 130 as an integral part of the base plate 106 facilitates heat transfer from the tab 130 to the main body 134 of the base plate. It is to be understood that the angle θ of the tab 130 relative to the base plate body 134 can be any desired angle as appropriate for the particular application of the lighting apparatus 100 .
A cut out portion 136 of the base plate 106 is provided surrounding the mount tab 130 . The cut out portion 136 provides space for components of the mount tab 130 to fit onto the base plate 106 . Also, the cut out portion 136 helps define the shape of the mount tab 130 . As discussed above, the mount tab 130 is preferably plastically deformed along the hinge line 132 . The length of the hinge line 132 is determined by the shape of the cut out portion 136 in that area. Also, a hole 138 is preferably formed in the hinge line 132 . The hole 138 further facilitates plastic deformation along the hinge line 132 .
Power for the light source assembly 100 is preferably provided through a power cord 78 that enters the apparatus 100 through a back side of the base plate 106 . The cord 78 preferably includes two 18 AWG conductors surrounded by an insulating sheet. Preferably, the power supply is in the low voltage range. For example, the power supply is preferably a 12-volt alternating current power source. As depicted in FIG. 18 , power is preferably first provided through a full wave ridge rectifier 140 which rectifies the alternating current in a manner known in the art so that substantially all of the current range can be used by the LED module 40 . In the illustrated embodiment, the LEDs are preferably not electrically connected to a current-limiting resistor. Thus, maximum light output can be achieved. It is to be understood, however, that resistors may be desirable in some embodiments to regulate current. Supply wires 142 extend from the rectifier 140 and provide rectified power to the LED module 30 mounted on the mounting tab 130 .
With reference again to FIGS. 9-12 , 16 and 17 , the housing 108 is positioned on the base plate 106 and preferably encloses the wiring connections in the light source assembly 100 . The housing 108 is preferably substantially semi-spherical in shape and has a notch 144 formed on the bottom side. A cavity 146 is formed through the notch 144 and allows visual access to the light source assembly 100 . A second cavity 148 is formed on the top side and preferably includes a plug 150 which may, if desired, include a marking such as a row number. In an additional embodiment, a portion of the light from the LED module 30 , or even from an alternative light source, may provide light to light up the aisle marker.
The housing 108 is preferably secured to the base plate 106 by a pair of screws 152 . Preferably, the screws 152 extend through countersunk holes 154 in the base plate 106 . This enables the base plate 106 to be substantially flat on the back side, allowing the plate to be mounted flush with the mount surface. As shown in FIG. 17 , threaded screw receiver posts 156 are formed within the housing 108 and are adapted to accommodate the screw threads.
The LED module 30 is attached to the mount tab 130 by the pop rivets 72 . The module 30 and rivets 72 conduct heat from the LEDs 32 to the mount tab 130 . Since the tab 130 is integrally formed as a part of the base plate 106 , heat flows freely from the tab 130 to the main body 134 of the base plate. The base plate 106 has high heat conductance properties and a relatively large surface area, thus facilitating efficient heat transfer to the environment and allowing the base plate 106 to function as a heat sink.
As discussed above, the first reflective strip 80 of the LED module 30 is preferably bent so as to form a convex trough about the LEDs. The second reflector strip 82 is attached to the base plate mount tab 130 at a point immediately adjacent the LED lamps 32 . Thus, light from the LEDs is collimated and directed out of the bottom cavity 146 of the housing 108 , while minimizing the number of reflections the light must make between the reflectors (see FIG. 6 ). Such reflections may each reduce the intensity of light reflected.
A lens or shield 160 is provided and is adapted to be positioned between the LEDs 32 and the environment outside of the housing cavity 108 . The shield 160 prevents direct access to the LEDs 32 and thus prevents harm that may occur from vandalism or the like, but also transmits light emitted by the light source 100 .
FIG. 20 shows an embodiment of the shield 160 adapted for use in the present invention. As shown, the shield 160 is substantially lenticularly shaped and has a notch 162 formed on either end thereof. With reference back to FIG. 18 , the mounting tab 130 of the base plate 106 also has a pair of notches 164 formed therein.
As shown in FIG. 16 , the lens/shield notches 162 are adapted to fit within the tab notches 164 so that the shield 160 is held in place in a substantially arcuate position. The shield thus, in effect, wraps around one side of the LEDs 32 . When the shield 160 is wrapped around the LEDs 32 , the shield 160 contacts the first reflector film 80 , deflecting the film 80 to further form the film in a convex arrangement. The shield 160 is preferably formed of a clear polycarbonate material, but it is to be understood that the shield 160 may be formed of any clear or colored transmissive material as desired by the user.
The LED module 30 of the present invention can also be used in applications using a plurality of such modules 30 to appropriately light a lighting apparatus such as a channel illumination device. Channel illumination devices are frequently used for signage including borders and lettering. In these devices, a wall structure outlines a desired shape to be illuminated, with one or more channels defined between the walls. A light source is mounted within the channel and a translucent diffusing lens is usually arranged at the top edges of the walls so as to enclose the channel. In this manner, a desired shape can be illuminated in a desired color as defined by the color of the lens.
Typically, a gas-containing light source such as a neon light is custom-shaped to fit within the channel. Although the diffusing lens is placed over the light source, the light apparatus may still produce “hot spots,” which are portions of the sign that are visibly brighter than other portions of the sign. Such hot spots result because the lighting apparatus shines directly at the lens, and the lens may have limited light-diffusing capability. Incandescent lamps may also be used to illuminate such a channel illumination apparatus; however, the hot spot problem typically is even more pronounced with incandescent lights.
Both incandescent and gas-filled lights have relatively high manufacturing and operation costs. For instance, gas-filled lights typically require custom shaping and installation and therefore can be very expensive to manufacture. Additionally, both incandescent and gas-filled lights have high power requirements.
With reference next to FIG. 21 , an embodiment of a channel illumination apparatus 170 is disclosed comprising a casing 172 in the shape of a “P.” The casing 172 includes a plurality of walls 174 and a bottom 176 , which together define at least one channel. The surfaces of the walls 174 and bottom 176 are diffusely-reflective, preferably being coated with a flat white coating. The walls 174 are preferably formed of a durable sturdy metal having relatively high heat conductivity. A plurality of LED lighting modules 30 are mounted to the walls 174 of the casing 172 in a spaced-apart manner. A translucent light-diffusing lens (not shown) is preferably disposed on a top edge 178 of the walls 174 and encloses the channel.
With next reference to FIG. 22 , the pop rivets 72 hold the LED module 30 securely onto a heat conductive mount tab 180 . The mount tab 180 , in turn, may be connected, by rivets 182 or any other fastening means, to the walls 174 of the channel apparatus as shown in FIG. 23 . Preferably, the connection of the mount tab 180 to the walls 174 facilitates heat transfer from the tab 180 to the wall 174 . The channel wall has a relatively large surface area, facilitating efficient heat transfer to the environment and enabling the channel wall 174 to function as a heat sink.
In additional embodiments, the casing 172 may be constructed of materials, such as certain plastics, that may not be capable of functioning as heat sinks because of inferior heat conductance properties. In such embodiments, the LED module 30 can be connected to its own relatively large heat sink base plate, which is mounted to the wall of the casing. An example of such a heat sink plate in conjunction with an LED lighting module has been disclosed above with reference to the self-contained lighting apparatus 100 .
With continued reference to FIGS. 22 and 23 , the LED modules 30 are preferably electrically connected in parallel relative to other modules 30 in the illumination apparatus 170 . A power supply cord 184 preferably enters through a wall 174 or bottom surface 176 of the casing 172 and preferably comprises two 18 AWG main conductors 186 . Short wires 188 are attached to the first and last contacts 62 , 64 of each module 30 and preferably connect with respective main conductors 186 using insulation displacement connectors (IDCs) 190 as shown in FIG. 23 .
Although the LEDs 32 in the modules 30 are operated at currents higher than typical LEDs, the power efficiency characteristic of LEDs is retained. For example, a typical channel light employing a neon-filled light could be expected to use about 60 watts of power during operation. A corresponding channel illumination apparatus 170 using a plurality of LED modules can be expected to use about 4.5 watts of power.
With reference again to FIG. 23 , the LED modules 30 are preferably positioned so that the LEDs 32 face generally downwardly, directing light away from the lens. The light is preferably directed to the diffusely-reflective wall and bottom surfaces 174 , 176 of the casing 172 . The hot spots associated with more direct forms of lighting, such as typical incandescent and gas-filled bulb arrangements, are thus avoided.
The reflectors 80 , 82 of the LED modules 30 aid in directing light rays emanating from the LEDs toward the diffusely-reflective surfaces. It is to be understood, however, that an LED module 30 not employing reflectors can also be appropriately used.
The relatively low profile of each LED module 30 facilitates the indirect method of lighting because substantially no shadow is created by the module when it is positioned on the wall 174 . A higher-profile light module would cast a shadow on the lens, producing an undesirable, visibly darkened area. To minimize the potential of shadowing, it is desired to space the modules 30 and accompanying power wires 186 , 188 a distance of at least about ½ inch from the top edge 178 of the wall 174 . More preferably, the modules 30 are spaced more than one inch from the top 178 of the wall 174 .
The small size and low profile of the LED modules 30 enables the modules to be mounted at various places along the channel wall 174 . For instance, with reference to FIGS. 21 and 24 , light modules 30 must sometimes be mounted to curving portions 192 of walls 174 . The modules 30 are preferably about 1 inch to 1½ inch long, including the mounting tab 180 , and thus can be acceptably mounted to a curving wall 192 . As shown, the mounting tab 180 may be separated from the curving wall 192 along a portion of its length, but the module is small enough that it is suitable for riveting to the wall.
In an additional embodiment shown in FIG. 25 , the module 30 comprises the circuit board without the mount tab 180 . In such an embodiment, the circuit board 50 may be mounted directly to the wall, having an even better fit relative to the curved surface 192 than the embodiment using a mount tab. In still another embodiment, the LED module's main body 56 is formed of a bendable material, which allows the module to fit more closely and easily to the curved wall surface.
Although the LED modules 30 disclosed above are mounted to the channel casing wall 174 with rivets 182 , it is to be understood that any method of mounting may be acceptably used. With reference next to FIGS. 26A-C , an additional embodiment comprises an LED module 30 mounted to a mounting tab 200 which comprises an elongate body portion 202 and a clip portion 204 . The clip portion 204 is urged over the top edge 178 of the casing wall 172 , firmly holding the mounting tab 200 to the wall 174 as shown in FIG. 26B . The lens 206 preferably has a channel portion 208 which is adapted to engage the top edge 178 of the casing wall 174 and can be fit over the clip portion 204 of the mount tab 200 as shown in FIGS. 26B and 26C . This mounting arrangement is simple and provides ample surface area contact between the casing wall 174 and the mounting tab 200 so that heat transfer is facilitated.
In the embodiment shown in FIG. 21 , the casing walls 174 are about 3 to 4 inches deep and the width of the channel is about 3 to 4 inches between the walls. In an apparatus of this size, LED modules 30 positioned on one side of the channel can provide sufficient lighting. The modules are preferably spaced about 5-6 inches apart. As may be anticipated, larger channel apparatus will likely require somewhat different arrangements of LED modules, including employing more LED modules. For example, a channel illumination apparatus having a channel width of 1 to 2 feet may employ LED modules on both walls and may even use multiple rows of LED modules. Additionally, the orientation of each of the modules may be varied in such a large channel illumination apparatus. For instance, with reference to FIG. 26D , some of the LED modules may desirably be angled so as to direct light at various angles relative to the diffusely reflective surfaces.
In order to avoid creating hot spots, a direct light path from the LED 32 to the lens 206 is preferably avoided. However, it is to be understood that pre-packaged LED lamps 32 having diffusely-reflective lenses may advantageously be directed toward the channel letter lens 206 .
Using LED modules 30 to illuminate a channel illumination apparatus 170 provides significant savings during manufacturing. For example, a number of LED modules, along with appropriate wiring and hardware, can be included in a kit which allows a technician to easily assemble a light by simply securing the modules in place along the wall of the casing and connecting the wiring appropriately using the IDCs. Although rivet holes may have to be drilled through the wall, there is no need for custom shaping, as is required with gas-filled bulbs. Accordingly, manufacturing effort and costs are significantly reduced.
Individual LEDs emit generally monochromatic light. Thus, it is preferable that an LED type be chosen which corresponds to the desired illumination color. Additionally, the diffuser is preferably chosen to be substantially the same color as the LEDs. Such an arrangement facilitates desirable brightness and color results. It is also to be understood that the diffusely-reflective wall and bottom surfaces may advantageously be coated to match the desired illumination color.
Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically-disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. | A modular light emitting diode (LED) mounting configuration is provided including a light source module having a plurality of pre-packaged LEDs arranged in a serial array. The module includes a heat conductive body portion adapted to conduct heat generated by the LEDs to an adjacent heat sink. As a result, the LEDs are able to be operated with a higher current than normally allowed. Thus, brightness and performance of the LEDs is increased without decreasing the life expectancy of the LEDs. The LED modules can be used in a variety of illumination applications employing one or more modules. | 8 |
FIELD OF INVENTION
The invention pertains to an internal combustion engine being typically conventional but having a cylinder liner that rotates with the intention of reducing piston assembly friction and piston ring and liner wear.
BACKGROUND OF THE INVENTION
The useful work of internal combustion engines is limited by their mechanical efficiency. On average, about 85% of the work available on the piston at full load is available as useful work on the flywheel due to internal engine friction. At lower loads, the above figure is even lower. Piston assembly friction (piston and piston rings) alone can account for up to 75% of the overall mechanical losses. Thus, piston friction reduction is highly desirable. Furthermore, engine parts are subject to wear that eventually limits the engine power and efficiency as well as increasing oil consumption, and increasing exhaust emissions. The most critical wear occurs on the piston rings and cylinder liners. Excessive wear requires engine overhaul or replacement. Thus, liner and ring wear reduction is also highly desirable.
Piston rings have two primary functions: Limiting oil flow into the combustion chamber and minimizing blowby (leak of high pressure combustion gas from the combustion chamber into the crankcase). Both functions are accomplished as high pressure combustion gases force the rings against the cylinders and the lower part of the piston groove and thereby seal the relatively large clearance between piston and liner. The top ring is subject to the highest pressure loading and thus suffers the most wear and has the largest contribution in friction.
The “rotating sleeve engine” is an invention that can significantly improve the lubrication conditions of the piston and piston rings, eliminate or significantly reduce wear and significantly reduce piston assembly friction.
In reciprocating piston engines, the piston linear speed is reduced to very low values at the regions with proximity to top and bottom dead centers. In those parts of the stroke, the sliding speed between the compression rings and the liner is insufficient for the maintenance of hydrodynamic lubrication. The protective lubricant film gradually breaks down and metal to metal contact occurs. The high cylinder pressure during the compression and power strokes loads the compression rings further, intensifying the phenomenon and expanding the portion of the stroke where the metal to metal contact occurs. Thus, localized wear on the liner around the dead centers and especially at the top is typical after prolonged engine operation. At the regions around the mid portion of the stroke, the piston speed reaches sufficient values for the hydrodynamic lubrication regime. The protective lubricant film prevents metal to metal contact, reduces the friction coefficient by up to two orders of magnitude, and essentially eliminates wear. This can be verified by the fact that the mid portion of the liner is always free of wear. Numerous frictional experiments reveal increased piston assembly friction around the dead centers due to the described phenomenon.
The above phenomenon is further illustrated by the Stribeck diagram shown in FIG. 1 as presented by Irving J. Levinson, Machine Design. This diagram shows the friction coefficient between two sliding surfaces in the presence of lubricant as a function of the “duty parameter” which is defined as the product of sliding speed and lubricant viscosity divided by the normal contact pressure of the surfaces. When two surfaces slide in the presence of lubricant, three possible modes of lubrication are possible. At very low sliding speed and high normal load, boundary lubrication is present. Metal to metal contact is unavoidable. Due to surface adhesion, high level of friction and wear is present. As sliding speed and thus the duty parameter increases, hydrodynamic oil film pressure builds up, supporting a larger portion of the normal load. Thus, the two surfaces are gradually separated by the oil film with less and less asperity contact and reduced adhesive wear (mixed regime). Finally, at higher sliding speeds (duty parameter values of 50 or higher according to the Graph 1), the hydrodynamic pressure supports the entire load resulting in full separation. The metal to metal contact as well as wear are eliminated. In the part of the cycle when the piston approaches a dead center, the sliding speed approaches zero. Furthermore, when the piston is in proximity to the top dead center, compression-expansion stroke, the high cylinder gas pressure increases the normal load between the liner and the piston rings (which are practically pressure activated sealing devices) further reducing the value of the duty parameter. The result is that for a significant portion of the cycle, the duty parameter falls bellow the value of 50, with the corresponding high friction coefficient and level of wear.
Graph 1. Stribeck diagram
The cylinder liner (also called the “sleeve”) of the rotating sleeve engine rotates with the objective of maintaining a non zero sliding speed and large values of duty parameter throughout the stroke. According to the Stribeck diagram, the friction coefficient is reduced by almost two orders of magnitude for that particular portion of the stroke. The rotation can be achieved via gear mechanisms from the crankshaft (similarly to a distributor or injection pump). For best results, the magnitude of the rotation needs to be high enough in order maintain the hydrodynamic lubrication regime between the compression rings and liner, even when the piston linear speed is zero and the cylinder pressure is at its maximum value.
In conventional engines, the rings must be free to rotate to minimize localized ring wear. However, both blowby and, for spark ignition engines, hydrocarbon emissions are affected by the relative azimuthal positions of the end gaps of the compression rings (Roberts and Matthews, 1996). When the rings are free to rotate, the engine designer cannot take advantage of these dependencies to help control blowby and hydrocarbon emissions. For the rotating sleeve engine, the rings can be pinned to prevent their rotation (which is no longer required to minimize wear).
In order to further investigate the feasibility of hydrodynamic lubrication just due to sleeve rotation, the Reynold's partial differential equation as shown by Hamrock (1994) was solved numerically in a situation that simulates a stationary piston ring subject to cylinder gas pressure while the liner rotates. The objective of the simulations is to explore the magnitude of the average hydrodynamic pressure obtainable by different liner sliding speeds and different ring profiles with a constant film thickness. The value of that pressure represents the maximum gas pressure that can be supported by the ring and still maintain the assumed film thickness. This pressure is the cylinder pressure at top dead center (TDC) compression stroke and is nearly equal to the peak cylinder pressure. The constant film thickness eliminates the contribution of squeeze film lubrication in the hydrodynamic film pressure and thus represents the worst case scenario for the rotating sleeve engine. It is as if the piston stays at top dead center indefinitely while the top compression ring is constantly loaded with high gas pressure The value for the lubricant viscosity was for a 20W oil as given by Hamrock (1984). This is a low viscosity lubricant that minimizes the hydrodynamic losses at mid stroke. A flat piston ring profile was assumed with surface irregularities as the only means for pressure build-up. This phenomenon is called “microhydrodynamic lubrication” Hamrock (1984). The surface irregularities were set equal to the combined surface roughness used by the ring-pack modeling performed by Tian and coworkers (1996) of 0.3 microns. The irregularities were assumed to be on the liner surface only (while the ring surface was assumed to be perfectly flat) and their shape was a 2 dimensional sinusoidal wave. With a 3 m/s liner sliding speed and a mean film thickness of 1 and 0.8 microns (within the range of hydrodynamic lubrication for this size of the combined asperity size according to Tian and coworhers) the average lubricant pressure was 16.03 and 28.27 atm respectively. Furthermore, the average pressure demonstrated an almost proportional variation with liner speed.
In order for the lubricant film of 0.8 microns minimum film thickness and with low viscosity oil to be able to support the typical peak pressure for spark ignition engines of about 50 atm, liner speeds of over 6 m/s are necessary. For heavy duty engines where the peak cylinder pressure can reach 100 atm, even higher speeds would be required. Note that if the liner speed is not sufficient for the peak cylinder pressure, the film thickness will further drop with some metal to metal contact at dead center. However, the boundary lubrication will be still confined to smaller part of the cycle, where the piston speed is nearly zero, and thus the energy losses due to boundary lubrication are still minimized.
In a preferred embodiment, a new ring profile is incorporated in order to enhance hydrodynamic pressure with lower liner speeds. In a conventional engine, the top compression ring is equipped with a barrel shape with the intention of creating converging surfaces (FIG. 6A) that enhance the build up of hydrodynamic lubricant pressure due to the up and down motion. Note that the depth of the barrel is ony 20 or 30 microns, and thus the profile looks perfectly flat to the naked eye. For the rotating sleeve engine, the depth of this shape can vary in the peripheral direction periodically as shown in FIG. 6B in order to create converging surfaces in the direction of sleeve rotation. Note that the shape is actually curved rather than angular as shown in FIG. 6 . At a point of maximum depth, the barrel shape remains like a typical compression ring. However, this depth drops linearly with peripheral displacement, until the barrel shape is reduced to a perfectly flat surface. Then, suddenly, the barrel shape is reintroduced and the same process repeats periodically. The result is that multiple “wedges” or converging surfaces are formed that enhance hydrodynamic pressure due to sleeve rotation. The length of these wedges along the periphery of the ring range between 1 and 1.5 ring widths.
The Reynold's equation was solved again for the new profile. With a film thickness of 0.8 microns and a sliding speed of 3 and 4 m/s, the average lubricant pressure was 88.10 and 110.82 atm respectively. Smaller film thickness and higher sliding speeds yield even higher pressure. As discussed above, if the slight piston motion present around dead center and squeeze film lubrication are included in the problem, similar hydrodynamic film pressure and/or higher minimum film thickness can be achieved for the short period of time that piston sliding speeds are low and cylinder gas pressure is high, with lower liner rotational speeds.
The above simulations indicate that hydrodynamic lubricant film pressure can be created at TDC or BDC just by the surface irregularities, even for a moderate liner rotation (3m/s corresponds to 409 rpm for a 5.5 inch bore engine) and with a low viscosity lubricant. With the proposed ring profile, the lubricant pressure can be dramatically increased even with a relatively large film thickness reaching the magnitude of typical peak cylinder pressure for heavy duty diesel engines at full load. Note that the proposed ring profile increases the flat portion of the ring improving sealing and increasing the effectiveness of squeeze film lubrication at dead center. Part of the converging surface that enhances hydrodynamic lubrication due to up and down motion has been sacrificed. However, results from the models by Tian and coworkers (1996), Lawrence (1988) as well as several experimental studies indicate that there is more than sufficient film thickness at mid-stroke for hydrodynamic lubrication. Furthermore, since at least some liner rotation will be retained at mid-stroke, the converging surfaces at the peripheral direction will remain active and substitute for the overall reduction of the barrel shape.
Moving sleeves have been proposed for use in prior internal combustion engine patents. However, in the prior art, the objective of sleeve motion is replacement of the conventional poppet valves with intake and exhaust slots that are exposed by the motion of the liner. For example Giorgio in U.S. Pat. No. 5,482,011, discloses an engine design where a liner rotates inside the engine block. The liner is tightly fitted on the block and is provided with a port which is aligned with similar ports on the block for the intake and exhaust processes. The rotational speed of the liner is restricted to one half the crank speed due to timing requirements. Akira in U.S. Pat. No. 5,191,863 describes an engine design with a ported rotating liner used for intake and exhaust processes. Again, the liner's motion is restricted by timing.
Some of the existing moving sleeve engines can show some improvements in the piston lubrication in respect to a stationary liner when sleeve rotation occurs at the dead centers, even though that was not the objective of the invention. An example is the series of sleeve valve engines developed by Ricardo before WWII (U. S. patent unknown) which shows great similarity to the engines described by Giorgio and Akira. However, in all these designs, the sleeve motion can not be optimized for friction optimization due to timing restrictions. Furthermore, even though Ricardo and coworkers (1968) reported some potential benefits in that particular design in terms of piston friction, the tight tolerances between the liner and block throughout the liner external area (necessary mainly due to the sealing requirements of the port openings provided on both the sleeves and stationary cylinders) introduced large loads on the driving mechanisms, minimizing the potential frictional benefits.
The ported engine designs shown by Richardo and coworkers as well as other US patents are using oil for the lubrication of the outside sleeve surface. Relatively large quantities of oil can be expected to enter the intake and exhaust flows through the ports. However, the oil consumption and resulting hydrocarbon emissions will not be compatible with modem US regulations. If different means of lubrication of the sleeves of the ported engines is attempted in order to avoid the excessive oil consumption (i.e. solid lubricant or dry lubrication), the advantages on wear and low friction coefficient inherent in fluid lubrication will not be present. The present invention incorporates conventional valvetrain, which prevents oil from entering the flow of intake or exhaust gasses.
In order to further support the usefulness of the invention, a study in the scientific literature concerning engine lubrication has been performed and demonstrated in the following pages. Issues of the design and operation of sleeve valve engines as related to engine lubrication are reported as published in relevant literature. The sources of piston ring wear are further analyzed. Also, the frictional savings due to the elimination of the friction component due to metal to metal contact of the piston rings with the liner have been estimated. The additional friction due to rotation has also been estimated and when compared to the frictional savings, it is smaller.
Background on Moving Cylinder Sleeves
Moving sleeves are not a new or untried engine feature. Ricardo and Hempson (1968) describes in detail the highly successful “sleeve valve” engines developed in the period between WWI and WWII and during WWII, mostly for aircraft applications (spark ignited engines). The objective of that design was the replacement of the conventional valve train and poppet valves. The motion of the sleeve would expose intake and exhaust slots at the right time in the cycle. The main advantage for aero engines was the reduction of the frontal area of the engine by the elimination of the rocker and/or overhead cam mechanisms. The shape and motion of the sleeves was designed in order to optimize the port exposure. A crank rotating at half the engine speed was connected by a ball joint to the sleeve, causing it to reciprocate and twist (at top dead center compression stroke, the sleeve's motion was momentarily purely rotational). Other advantages of these engines included central spark plug placement for denotation reduction and volumetric efficiency improvements. A second set of rings was necessary in order to seal the sleeve-cylinder head gap. This ring-pack was installed on the cylinder heads and was stationary.
During the early 20's two experimental single cylinder engines were constructed in Ricardo's laboratory in order to further explore the potential of the sleeve valve concept. One was a conventional poppet valve engine with 4 valves, the other a sleeve valve engine. The two units were similar in every other respect. During the test, it was discovered that a “puzzling” feature of the sleeve valve engine was its lower frictional losses, in spite of the larger number of moving parts and large rubbing surfaces. Ricardo attributed this effect to the possibility of elimination of piston ring boundary lubrication due to the continuous ring-liner motion and continuous fluid lubrication of the rings. That theory was confined by the observation that the sharply localized wear, always found in the liners of poppet-valve engines at the point where the top piston ring comes to rest at top dead center, was absent in the sleeve valve. Later tests on large number of sleeve- and poppet-valve engines of various shapes and sizes indicated that the overall mechanical losses of the sleeve-valve engine were usually less than those of the poppet-valve. According to Setright (1975), the Bristol “Centaurus”, a radial 18 cylinder air cooled high performance aero engine is holding the record for the longest operation between overhauls for a piston aero engine (3000 hours). Furthermore, the Nappier Sabre, a 24 cylinder liquid cooled high performance sleeve valve aero engine could maintain its combat rating almost indefinitely due to improved piston lubrication, while engines of the period with similar or lower Brake Mean Effective Pressure (BMEP) could maintain combat rating for only 5 minutes.
Evidence from the sleeve valve engines also indicates that the maintenance of hydrodynamic lubrication of the compression piston rings by the liner motion is feasible even with the relatively low rate of liner rotation that those engines had when the piston was at top dead center (TDC) compression-expansion stroke. Thus, wear protection of piston rings and liner is also feasible. Also, in the previous design, the primary function of the sleeve motion on the sleeve valve engines was not friction reduction. The clearance between sleeve and block was held low for gas sealing purposes around the intake and exhaust ports that were drilled on the sleeves and block. In the current invention, the sleeve- block clearance can be chosen for friction optimization. Drawings of the sleeve valve engines reveal large rubbing surface between the block and sleeve. The current invention reduces this rubbing area (by the introduction of the journal bearings) to the minimum necessary for fluid lubrication, and optimizes the sleeve motion for piston friction as well as sleeve friction. Thus, much higher frictional benefits are possible. Also, the reduction or elimination of metal to metal contact at TDC in those sleeve valve engines was possible due to the relatively low peak cylinder pressure typical of a spark ignition engine (compression ratio of about 6.5:1). In order to achieve the same effect in a turbocharged heavy duty diesel engine with a compression ratio of 15:1 or higher and peak cylinder pressure of about 100 atmospheres, higher rates of rotation and/or the proposed ring profile will be necessary.
Squeeze Film Lubrication
Lawrence suggests the possibility that “squeeze film” lubrication can protect the compression rings even at the critical moments when the piston approaches a dead center under certain operating conditions. Squeeze film lubrication is a tribological situation where, even though the sliding surfaces suddenly come to a complete stop, due to lubricant viscosity and inertia, the surfaces could still remain separated for a certain amount of time.
However, experimentation by Gauthier and coworkers (1987) on a diesel engine indicate that squeeze film lubrication can completely prevent metal to metal contact only if very high viscosity lubricant is used. However, when the lubricant viscosity is increased, hydrodynamic piston friction at mid stroke will increase dramatically, with a strong penalty in overall engine efficiency. Furthermore, typical lubricants cannot maintain that level of viscosity at operating temperature. Experiments by Mitsumoto and coworkers (1989) on diesel engines also show that increasing the lubricant viscosity improves the durability of the engine, with a penalty in efficiency.
Similar studies performed on spark ignited engines (Takiguchi et al., (1988); Ku et al., (1988); Ohmori et al., (1993)) show that squeeze film lubrication cannot prevent metal to metal contact of the compression rings under any operating condition. However, slight reduction of wear followed by an increase in overall friction was observed when the lubricant viscosity is increased.
The fact that squeeze film lubrication is possible under extreme conditions on diesel engines with higher viscocities, and unlikely in spark ignition engines is mainly due to the ring design differences. The design of diesel engines is dominated by durability requirements, and thus they are generally equipped with wider compression rings. The larger surface area will enhance the squeeze film lubrication. However, a wider ring will also exhibit higher hydrodynamic friction at mid stroke. With a rotating liner, dependence on squeeze film lubrication will be minimized. Therefore, the piston ring width can be reduced without any durability trade offs. Thus, the mid-stroke hydrodynamic friction of diesels (which seems to be relatively large in respect to spark ignition, as shown bellow) can be also reduced with the new concept.
Boundary Contribution
In the current invention, the friction reduction is achieved mainly by the elimination or severe reduction of the boundary contribution in piston ring friction. A comprehensive literature review was conducted in order to estimate the contribution of boundary lubrication in the total piston friction in different kinds of engines and operating conditions.
In order to illustrate the typical piston friction behavior and the boundary lubrication at the dead centers, the crank-angle resolved data by Ku et al. for a 4.1 liter Cadillac spark ignition engine at 2000 rpm, light load are presented in Graph 2. A complete thermodynamic cycle is shown (two complete crankshaft revolutions). The x-axis shows crank angle degrees (dead center at 0, 180, 360, 560, and 720). The y-axis show piston friction force (N) and piston speed (m/s*10). The spikes at top dead centers clearly indicate the existence of asperity contact and boundary lubrication. Please note that in many similar experiments on different engines and operating conditions, those spikes are more clearly defined. The doted line shows the calculated instantaneous piston speed. The flat line (that alternates values between 0 and 10) shows where the friction can be considered predominantly hydrodynamic (value of 0) and boundary (value of 10).
Graph 2. Piston assembly friction on a 4.1 liter Cadillac V8 engine
For different operating conditions, the boundary and hydrodynamic contributions are continuously varying. Clearly, the hydrodynamic contribution is increasing with speed. Patton et al. suggests a nearly linear variation of the hydrodynamic friction torque portion with engine speed for spark ignited engines. This is supported by a number of experimental results (Patton) as well as the Stribeck diagram. Patton also suggests that the hydrodynamic portion is not sensitive to engine load. The piston friction which is the largest contributor of the hydrodynamic portion due to its larger than the rings rubbing area could be affected by load by the reduction of the oil film thickness in the thrust side during the power stroke. However, the film thickness will increase on the anti thrust side, making the overall effect not as severe. From the Stribeck diagram, it can be seen that if in a situation well into the hydrodynamic regime the load increases, the friction coefficient drops. It is unclear what will happen to the friction force (which is the product of normal load and friction coefficient) but it is clear that the sensitivity is not as high as the boundary friction where the friction coefficient is flat (if well into the boundary regime) or rapidly increasing with load (if in the mixed regime where the friction coefficient could be very sensitive to the duty parameter, and thus load). Thus, it seems justified for Patton et al. to attribute the piston assembly fmep (friction mean effective pressure) increase due to increasing load entirely on increase of boundary friction. This may not be entirely accurate for reasons described above, but it seems like a reasonable assumption.
In contrast with spark ignition engines, the piston assembly finep for diesel engines does not always increase with increasing load. Ball et al. conducted friction experiments on two 1.6 liter automotive engines, one diesel and one spark ignition. Although in the second case, the friction increased with load, it decreased in the second. This was attributed to the fact that the lubricant viscosity on the cylinder walls dropped due to the increased temperatures at higher loads. Thus, even though the boundary friction increased due to the increased gas loads on the rings, the hydrodynamic portion dropped even more. Gauthier et al. also supports the competing effects of increasing temperature and gas loading. In their measurements, the total piston friction was insensitive to load. This effect was not as apparent in Marek et al.'s experimental results. In their case, the gas loading term prevailed and the friction increased with load (in spite of the fact that they held the oil sunp temperatures lower than normal operating conditions, and thus amplifying the hydrodynamic effect). At 980 rpm, the friction at full load was 31.4% higher than the motoring conditions. The different behavior of these two engines (Gauthier's and Marek's) is probably due to design differences of the two engines. For example Gauthier's engine had a larger stroke (110 mm compared to 95 mm) which resulted in higher mean piston speeds.
The reason that diesel engines are generally less sensitive than spark ignited is partly due to the fact that Diesel engines run unthrottled. Thus, during the compression stroke, the cylinder pressure versus crank angle trace does not change with load. On a spark ignition engine, the density of the charge drops at lower loads, and so does the compression pressure.
However, the design differences of diesel and spark ignition engines also contribute to the different frictional behavior. Generally, diesel engines have larger piston skirts and wider piston rings. The higher durability requirement of the diesel engines and the lower speed range seem to be the main reason for this difference. Furthermore, the stroke (as well as the stroke to bore ratio) is higher on diesels, which creates a higher mean piston speed. As a result of the above, the hydrodynamic contribution should be higher in diesels (for a given speed). Thus, a reduction of lubricant viscosity at increasing loads can have a significant effect on total frictional losses. In a spark ignited engine the changes in the hydrodynamic portion seem not to be sufficient to significantly impact the total losses and counteract the increase of boundary friction.
By varying certain parameters that directly affect the hydrodynamic portion, Gauthier at al. was able to calculate the boundary contribution at 1250 rpm for different lubricant viscosity for their engine. The approximate boundary contribution on piston friction and total piston friction mean effective pressure (FMEP) for 1250 rpm motored is shown in Graph 3 and 4 respectively. The small increase in FMEP at very low viscocities is due to the very rapid increase of boundary friction. In the viscosity ranges at operating temperatures (less than 10 mm 2/ s) the boundary contribution ranges between 12 and 25%. At the viscosity of minimum friction (4 to 5 mm 2 /s) the boundary contribution is over 15%. It can be expected that if this engine was firing and under significant load, the boundary contribution would have been higher. If a rotating liner is applied on this engine with the optimum lubricant viscosity (about 5 mm 2 /s), it is possible to eliminate that 20% boundary contribution (resulting from metal to metal contact between the compression rings at the dead centers). The rotating liner, apart from the continuation of the fluid lubrication of piston rings at dead centers, will also create extra hydrodynamic pressure on the piston skirt when the large thrust forces are applied by the connecting rod (similar to a journal bearing). Thus, the piston skirt surface area can be reduced without reducing the minimum film thickness between liner and piston and without increasing the chances of metal to metal contact between piston and liner (according to the Stribeck diagram, an increase in the load per unit area can be offset by the increase of the sliding speed keeping the value of the duty parameter unchanged). Thus, the reduction of the hydrodynamic friction of the reciprocating piston motion due to that skirt size reduction will overcome the increase of total friction caused be the relative rotary motion introduced between the piston and liner. Furthermore, the fact that the boundary term will be considerably reduced or eliminated, the FMEP will continue dropping with decreasing oil viscosity beyond the value of 5 mm 2 /s.
Graph 3. Boundary contribution
Graph 4. Total friction
The friction of the engine used in Marek's experiment was far more sensitive to load than the one that Gauthier et al. used. Therefore, the boundary contribution in that engine is higher, with higher frictional benefits for the present invention. However, no effort was done to quantify the boundary contribution in that study. Needleman and coworkers expect large boundary contributions in diesel engines as well and suggest that “due to boundary lubrication, 40 to 50% of frictional losses of an engine are attributed to piston/ring assembly with ⅔ of the losses assigned to the top compression ring”. In general, the frictional savings with the rotating sleeve concept applied on diesel engines could be higher than in the case of Gauthier's study.
As discussed earlier, due to different design trends and lower durability requirements, the boundary contribution in spark ignition engines can be expected to be higher. Patton et al. have developed empirical equations that estimate the piston assembly boundary and hydrodynamic friction contributions as a function of speed and load. By using the equations proposed by Patton, at 2000 rpm, the boundary contribution on total piston friction on a typical automobile engine can be calculated as high as 50% and approximately 20% at a speed of 6000 rpm at medium load and intermediate values in between.
Spark ignition automotive engines are required to operate over a wide speed range and the ringpack design is a compromise between wear and high speed friction. If the rotating sleeves are driven with some sort of gear mechanism, the optimization of the gear ratio is also a compromise. If the gear ratio between the crankshaft and the sleeves is selected so that the sleeve rotates at a sufficient magnitude for compete elimination of boundary friction at low engine speeds, excessive hydrodynamic friction could result at higher speeds. On the other extreme, if the gear ratio is such that just sufficient sleeve speed is present at high engine speeds, the sleeve speed at low crankshaft speeds will drop proportionally and may not be sufficient for complete elimination of the boundary/mixed friction at top dead center and high load when low viscosity oil is used. However, even in that case (some metal to metal contact occurs at top dead center compression stroke at high load and low engine speed) the portion of the stroke that this happens is confined to a much smaller part of the stroke around the dead center in respect to a conventional engine because the sliding speed of the compression ring is always held at well above the zero value. Since at these parts of the stroke the piston speed is very low, the piston energy losses due to boundary friction will still be far less than the in a conventional engine. Furthermore, due to the very large contribution of boundary/mixed friction at low speeds in conventional spark ignition engines, the frictional benefits could be very significant (especially at higher loads). At higher speeds when the piston and sleeve are moving faster, complete boundary elimination seems more likely but with a smaller potential for friction reduction.
In spite of the possible presence of some metal to metal contact at low speeds, some useful wear reduction can be possible in engines with a large speed range variation. Ohmori and coworkers (1993) showed that at 6000 rpm the instantaneous ring wear could be an order of magnitude higher than at 2000 rpm. Thus, even if some boundary friction still exists at low speed, the resultant wear will not be so significant. The more significant wear rate normally present at higher engine speeds can be eliminated.
Friction Calculations
The following calculations apply to a spark ignition automotive engine. The friction model developed by Patton et al. was used. The driving mechanism considered was the one of alternating sleeve speed (high magnitude when piston close to a dead center, low when at mid stroke, no reversal of direction considered, see embodiments). Note that in a 4 cylinder engine where all pistons reach a dead center at the same time, only one alternating speed mechanism needs to be fabricated. Gears interconnecting adjacent sleeves can duplicate the motion for the other 3. No reduction on piston skirt size was considered.
For the calculations, it was assumed that the driving mechanism was designed so that the sliding velocity between the piston ring and the sleeve is approximately constant in magnitude and at the value of the peak piston speed of a conventional engine with similar dimensions. This is a conservative figure, since the required speed for fully hydrodynamic lubrication is less, especially at higher engine speeds. Thus, at higher engine speeds, the friction mean effective pressure could be expected high due to the high velocities of the additional moving parts.
Two engines were modeled: one conventional and one designed according to the above recommendations. For both engines the following dimensions were used: Bore=85 mm, Stroke=75 mm, Compression Ratio=10:1, Cylinder Displacement=426 cc, Connecting rod Length=118 mm. A relatively small engine was chosen because this model was derived for small passenger car engines.
In this model, the reciprocating friction was divided into three terms. The first term was the hydrodynamic component mostly from the piston skirt and the connecting rod bearing. The second term was the mixed lubrication term mostly due to ring static tension and therefore is independent of engine load. Finally, the third was the mixed lubrication of the compression rings due to gas loading and was directly proportional to manifold pressure.
In the rotating sleeve case, the two mixed lubrication terms were not included since hydrodynamic lubrication is assumed. The fact that the piston ring lubrication is now hydrodynamic will be accounted by the increase of the hydrodynamic term considered bellow. Furthermore, since the friction in the hydrodynamic lubrication is not as strong a function of the normal force as of sliding speed, the fmep (friction mean effective pressure) on the new design was assumed independent of gas loading and therefore intake manifold pressure.
However, the hydrodynamic term should be higher in the new design in order to account for the extra friction due to sleeve rotation. The hydrodynamic friction term between the rotating sleeve and the piston should be included. Even though this force is indirectly increasing the friction (through the sleeve driving mechanism), for computational purposes, it was assumed directly acting. The overall increased friction was estimated as follows. The hydrodynamic term for the conventional engine was considered as the mean value of an alternating sinusoidal friction of a certain amplitude A. fmep = ∫ 0 x A · sin ϕ ϕ π where ϕ is crank angle
By solving the integral, the peak value A was calculated as
A=π*fmep/ 2
Then, the hydrodynamic fmep for the new engine was assumed equal to that peak value since the sliding speed remained always high. The fact that the hydrodynamic term in the engine model included the connecting rod friction as well, made the estimation even more conservative. The fact that at peak piston speed the sleeve still had to slightly rotate should not affect the friction significantly, since the two velocities were normal to each other. Even if the sleeve surface minimum linear speed is 20% of the piston speed at that instant, the resultant vector is less than 2% increased in magnitude. Note that Patton's model includes the ring hydrodynamic portion in these terms. Thus, the overall increase of these terms does take under consideration the increase in the viscous ring friction.
The friction due to the two journal bearings that support the sleeve on the block was also included. A finite element analysis code for journal bearing performance prediction was used. The bearings had to be designed in order to take the side loads transferred from the connecting rod during the power stroke. The two following load criteria derived from the UT Fractal Engine Model had to,be met by the bearings. 50 Atm peak pressure at 20 degrees after top dead center at 1000 rpm and 100 Atm peak pressure (highly exaggerated value to account for a safety factor) at the same crank angle at 3000 rpm. After the design was completed, the sleeve bearings were assumed to rotate at 54% of engine speed for the fmep contribution. This was estimated from the fact that the peak sleeve linear speed should match the peak piston speed. This corresponds to an angular speed equal to the engine speed times stroke to bore ratio. The minimum speed should be 20% of the maximum in order to minimize losses. Finally, the mean would be roughly the average of the two.
The losses from the driving mechanisms were not included. However, gears or chains can be designed to operate at relatively high efficiencies and therefore were not expected to alter the results by much. Graph 4 shows the results obtained.
Graph 5. Piston assembly friction comparison of the proposed design with a conventional engine, high sleeve speed.
Note that for speeds bellow 3600 rpm and medium load, the new design demonstrates lower fmep. The break even point is raised to 4200 rpm for full load. At engine speeds that most vehicles cruise, the fmep reduction is evident.
If the engine is required to operate at higher engine speeds for long periods of time, the sleeves could be geared lower in order to reduce the fmep at these speeds. The trade off could possibly be slightly higher friction and some wear at lower engine speeds as compared to the high sleeve speed scenario, due to the possibility of not having enough sliding speed for a fully hydrodynamic film. The previous assumption that the sleeve speed at TDC needed to be equal to the maximum piston speed in order to retain the fluid lubrication on the compression rings at dead centers is excessive even for medium speeds. Drawings of the sleeve valve test engine used on Ricardo's experiments show that the sleeve linear speed was only a fraction of the peak piston speed and during those tests the engine speed did not exceed 2000 rpm (however, the ring pack used in that engine was of different design compared to modem automotive engines, and the lubricant viscosity was probably high compared to modern energy saving multigrade oils). Furthermore, the numerical solutions of the Reynold's equation discussed earlier indicate that with a conventional ring profile and an SAE20W oil, a sleeve surface speed of 3m/s can create film thickness of well over 0.5 microns at TDC with the typical peak cylinder pressures of spark ignition engnes. With the revised ring profile (FIG. 8 ), even lower sleeve speeds will suffice. The average sleeve speed is assumed half of the first case, and therefore the increase in the hydrodynamic piston friction is also half. The reason is that since the sleeves are driven by gear mechanisms, the peak sleeve speed is proportional to crankshaft speed. Therefore, the sleeve surface speed at very low rpm and high load may be insufficient for complete asperity contact. Also, the model used to generate the rotating sleeve engine friction ignores mixed lubrication, and thus this potential small increase caused by mixed lubrication does not show in the graph. However, as discussed in a previous section, the low sleeve speed rotating sleeve engine is still expected to show lower friction than conventional engines, even at this operating condition.
Graph 6. Piston assembly friction comparison of the proposed design with a conventional engine, low sleeve speed. Note that in the above graph, the fmep for the new design could be underestimated at low engine speeds.
For engines that operate at fairly narrow rpm range, the sleeve speed could be optimized for wear and friction.
Additional Efficiency Benefits
The rotating sleeve concept can further improve overall engine efficiency indirectly with mechanisms that are not as obvious.
According to Gardner at al. the optimum compression ratio on Direct Injection (DI) diesels is limited by the reduction of mechanical efficiency at high values of compression ratio, mostly due to piston ring friction. In that study, it was shown that the indicated thermal efficiency (engine efficiency disregarding frictional losses) was increasing with increasing compression ratio throughout the range of 13 to 22 to 1 that was tried. However, the friction of the piston rings was also increasing with increasing compression ratio. This effect limited the optimum compression ratio (for best brake thermal efficiency) to a value of 15:1. With the application of the rotating sleeve concept, a severe reduction of piston ring friction will be achieved, and thus, the optimum compression can be higher, achieving even higher thermal efficiency. The higher compression ratio will also help cold starting performance that is usually a problem with diesel engines . According to the same study, satisfactory cold start performance is normally achieved with compression ratios higher than the optimum value for best efficiency.
In conventional engines, the stress on the block caused by the cylinder head bolts as well as thermal stresses, cause liner distortions. According to Lawrence (1990) those distortions can alter the perfectly circular shape of the cross section of the cylinder achieved by the machining process. These distortions cause increased blow-by and oil consumption. Note that this distortion is more pronounced in the upper part of the liner that corresponds to piston locations where the gas pressure and thus the potential for blow by is the highest. In the proposed design, the liner will not be loaded from the cylinder head bolts and thus, free of mechanical distortions. The continuous rotation will eliminate or reduce any temperature gradients around the liner. The perfectly circular liner cross section will result in a more effective gas sealing, and thus reduction of blow-by and oil consumption. Any reduction of blow-by can be considered as direct efficiency benefit.
Conclusion
It has been demonstrated that the new design can provide useful friction reductions and piston ring and liner wear elimination or severe reduction for a variety of engines. More efficient engines of virtually infinite life can be produced. Rotating sleeve engines could be designed in such a way that valve train components (that will still wear with the existing rate) can be rapidly replaced without requiring a complete disassembly. Thus, the engine overhaul cost can be significantly reduced.
Best results are expected on engines that operate at relatively low speed ranges. Then, the motion of the sleeve can be tailored for one speed without excessive hydrodynamic losses (due to excessive sleeve speeds) or boundary friction (due to too low sleeve speeds). However, the durability and frictional reduction requirement could make certain applications more feasible than others. Engines can be designed to operate at high brake mean effective pressures and engine speeds, and thus more power per engine weight without sacrifices in their durability. Modern diesel engine emission requirements demand the use of excessive exhaust gas recirculation that can increase corrosive wear on rings and liners (Needleman and Mandhavan, 1988) increasing the need for anti-corrosion additives. The fluid lubrication will create an immunity of the cylinder wear in the chemical composition of the lubricant. Additives that were specifically formulated for piston ring lubrication may not be necessary on rotating sleeve engines. Thus, the products of the combustion of the lubricant (that happens to some degree in all engines) may not be as toxic as they have to be for conventional engines.
REFERENCE LIST
The following scientific literature was used for the research study shown above:
Ricardo, H., R. and J. G. Hempson The High Speed Internal Combustion Engine Fifth Edition, Blackie & Son Limited 1968
Setright, L. J. K. Some Unusual Engines Mechanical Engineering Publications Ltd 1975
Hamrock J. B. Fundamentals of Fluid Film Lubrication McGraw-Hill, Inc.
Lawrence J. B. Effect of cylinder distirtions and piston ring design on oil consumption and friction losses in automobile engines DE-AC02-90236
Ball,. W. F., N. S. Jackson, A. D. Pilley, and B. C. Porter The friction of a 1.6 liter automotive engine—gasoline and diesel SAE Paper 860418
Gauthier A., and B. Constans Lubricant effects on piston/rings/liner friction in an instrumented single cylinder Diesel Engine SAE Paper 872034
Takiguchi M., H. Kituchi, and S. Furuhama Influence of clearance between piston and cylinder on piston friction SAE Paper 881621
Needleman W. M., and P. V. Mandhavan. Review of lubricant contamination and diesel engine wear SAEPaper 881827
Ku Y. G., and D. J. Patterson Piston and ring friction by the fixed sleeve method SAE Paper 880571
Patton, K. J., R. J. Nischke, J. B Honeywood Develpment and evaluation ofa friction model for spark ignition engines SAE Paper 890836
Mitsumoto S., T. Miyamoto, and H. Yamamoto Effect of Lubricant viscocity, additives and ash content on durability in a heavy duty diesel engine SAE Paper 892050
Yoshida, H. K. Kusama, and J. Sagawa Effects of surface treatments on piston ring friction force and wear SAE Paper 900589
Marek L. S., W. Bryzik, and N. A. Heuein Effect of load and other parameters on instanteneous frictional torque in reciprocating engines SAE Paper 910752
Ohmori T., M. Toyama, and M. Yamamoto Influence of oil viscocity on piston ring and cam face wear SAE Paper 932782
Ting L. L Development of a reciprocating test rig for tribological studies of oiston engine moving components—Part I SAE Paper 930685
Gardner T. P., Henein N. A. Compression Ratio Optimization in a Direct Injection Diesel Engine—A Mathematical Model SAE Paper 880427
Tian T, V. W. Wing, J. B. Heywood A piston ring - pack film thickness and friction model for multigrade oils and rough surfaces SAE Paper 962032
SUMMARY OF INVENTION
The invention is directed to an internal combustion engine having one rotating sleeve per cylinder that is supported by two journal bearings. The objective of the rotation is to maintain the sliding motion between the piston rings and liner in order to maintain the hydrodynamic lubrication regime throughout the stroke. The rings will be held stationary by the friction between the piston grooves and rings. However, if necessary, the rings can be pinned on the piston to prevent their rotation. Unlike the typical sleeve valve engine, the surface area where tight tolerances between the sleeve and the block exist are confined to the minimum necessary for reliable hydrodynamnic support of the sleeve, minimizing the friction due to liner rotation. The intake of the fresh charge (or fresh air in the case of a Diesel) and exhaust of the combustion products are accomplished via conventional popper valve arrangement. A flange on the upper part of the liner transfers the thrust loads to the cylinder head and the block. Furthermore, the flange reinforces the upper part of the sleeve preventing or minimizing the sleeve expansion due to high cylinder pressure that occurs when the piston is in proximity to top dead center (TDC) which could otherwise take up the clearance of the upper journal bearing. This has been reported by Ricardo to be a typical phenomenon in sleeve valve engines without a flange, causing a serious penalty in friction and wear between the sleeve and the block. A set of pressure activated sealing devices are installed on the upper part of the sleeve to prevent high pressure combustion gases from entering the space between the liner and the block. The journal bearings that support the sleeve are supplied with pressurized oil from the oil pump lubricating the bearings. Lubricant leakage from these journal bearings fills up the space between the liner and the block and also lubricates the sealing devices on the upper part of the sleeve and the flange which acts as thrust bearing. The excess lubricant is removed by oil return passages and by direct leakage back to the oil pan. The oil that surrounds the liner will remove excess heat from the engine, and may be used as the sole coolant fluid of the engine. In fact, the motion of the liner will enhance heat transfer from the liner to the oil.
The sleeves are driven by the crankshaft via gear mechanisms. Since the motion of the sleeve is not related to port operation unlike typical sleeve valve engines, the motion of the liners is independent of valve timing. Thus the final gear ratio between the crank and the sleeves can be optimized for friction optimization and wear minimization. For example, a turbocharged diesel engine with high peak cylinder pressure and low operating speeds will have such a gearing that the sleeve speed will be high for a given crankshaft speed in order to ensure full hydrodynamic lubrication of the piston rings at TDC compression stroke. On the other hand, an engine with high operating speeds and lower peak cylinder pressure like a spark ignition engine needs lower sleeve speed for a given crank speed to ensure hydrodynamic lubrication, and excessive sleeve speed would only result in excessive hydrodynamic losses. Furthermore, in applications where frictional losses are more important than wear of piston rings and liner, the sleeve speed can be less than the minimum necessary for full hydrodynamic lubrication at dead center compression stroke. In that case, some metal to metal contact may be likely at certain operating conditions (full load) but the overall losses due to sleeve rotation will be still kept low. Still, the metal to metal contact between the top compression ring and the liner will be confined on the small part of stroke when piston speed is very close to zero. The overall transmission ratio between the crank and sleeve can be adjusted by changing the gear ratio of the relevant gears.
The sleeve speed can be constant (for simplicity) or with alternating value (without reversal) for friction optimization. In the latter embodiment, the objective of alternating the value of the sleeve rotation is that at the mid portion of the stroke, the piston speed is sufficient for hydrodynamic lubrication regardless of liner rotation. Therefore, liner rotation at that part of the cycle does not offer any significant frictional benefits as at around the dead centers. Thus, minimizing the rate of rotation will reduce the additional friction caused by the liner rotation. However, even at mid stroke, a minimum rotational speed of the sleeve will have to be retained (even when the piston is at its peak speed) in order to retain the hydrodynamic oil film in the journal bearings with some small expense in friction. Then, as the pistons slow down, the driving mechanisms will gradually accelerate the sleeves. When the pistons come to a fall stop, the sleeves will be at their peak speed. Then as the pistons speed up again, the sleeves could gradually slow down at their minimum speed when the pistons are at their maximum. An eccentric driving mechanism or a geartain based on the “Geneva Wheel” achieves this motion. The kinetic energy stored in the sleeves at peak angular speed will return to the system during deceleration. In a multi-cylinder engine, the sleeves could be driven by independent mechanisms. However, gears installed on the outside of the sleeve surface (either the top or the bottom) could mesh with the sleeves of neighboring cylinders eliminating the need for individual driving mechanisms. The above driving method is particularly attractive if the constant sleeve speed embodiment is chosen, or if the alternating sleeve speed is to be used on a four cylinder engine (or in any in-line engine with a flat crankshaft design) where all pistons reach a dead center at the same time. In the latter case, the alternating magnitude rotation needs to be created by one mechanism and the motion will be duplicated from liner to liner.
Graph 7 shows the optimum liner speeds for different engine applications as derived from the numerical solution of the Reynold's equation. Again, the lubricant viscosity assumed is for an SAE 20 oil, a low viscosity lubricant that has the potential of minimizing the hydrodynamic losses at mid-stroke. The minimum film thickness is 0.8 microns which corresponds to a relatively small thickness but lies within the limits of hydrodynamic lubrication (based on the relevant literature). However, if the film thickness drops bellow that value, metal to metal contact is eminent. The average lubricant pressure shown in Graph 7 indicates the maximum cylinder pressure that can exist at TDC compression/expansion stroke, without any reduction in the film thickness. Note that the pressure at TDC compression/expansion stroke is very close to the peak cylinder pressure that typically occurs between 10 and 20 crank angle degrees after TDC. The two lines shown in Graph 7 show a typical (lower) and the revised compression ring profile (upper curve).
The gear selection for the sleeves is done as follows. The most frequent operating engine speed and load are selected. The corresponding peak cylinder pressure needs to be determined. Then, referring to Graph 7 depending on which compression ring profile is selected, the sleeve needs to rotate with an angular velocity such that the inner liner surface and peak pressure are at a point on the corresponding line or just bellow it. The equation that relates the liner surface speed with the liner rotational speed is: V=Ω*R where V is velocity (m/s), R is bore radius (m) and Ω is sleeve angular velocity (rad/s). Then, simple arithmetic will determine the overall ratio of teeth of the driving gears. This applies for both constant and alternating speed. For the latter case, the maximum liner speed needs to be properly selected and is the one that is relevant to Graph 7. For example, a spark ignition engine with most frequent operating speed of 3000 rpm, a peak cylinder pressure of 35 atm, and a conventional ring profile, requires a sleeve angular velocity such that the inner liner surface speed is at 4 m/s. If the speed is less than that, the minimum film thickness will drop bellow 0.8 microns at TDC, full load, and some metal to metal contact and wear could occur at TDC. For a turbocharged diesel engine with most frequent operating speed of 1200 rpm, a peak cylinder pressure of 95 atm, and a revised compression ring profile, about 3.5 m/s or less is required. Note that the revised compression ring is recommended, since the liner rotation requirements is minimized with reduced sleeve friction. In that particular example, at engine speeds of higher than 1200 rpm, the sleeve speed will increase proportionally since it is driven by gear mechanisms by the crankshaft, ensuring fluid film lubrication of the ring. At lower speeds, if the peak cylinder pressure at full load remains approximately similar, some boundary friction is likely. Thus, if wear elimination is of paramount importance for the application, higher sleeve speed may have to be selected with an expense in high speed hydrodynamic losses. However, in typical heavy duty engines, the turbocharger speed drops at lower engine speeds due to reduced exhaust flowrate (lower turbocharger speed), resulting in lower peak cylinder pressure.
Also note that prior ported engines with a conventional ring profile and with a peak pressure/sleeve speed point that falls above the dotted line of Graph 7, the film thickness at TDC would drop bellow 0.8 microns with metal to metal contact, increased piston and sleeve friction and wear being very likely. However, if a lubricant with higher viscosity was used, the metal to metal contact could have been minimized or avoided, with an expense in the hydrodynamic friction of the piston at mid-stroke and in sleeve friction. In the case of the sleeve valve engines described by Ricardo, the typical compression ratio of those engines was around 6:1 due to detonation limitations, resulting to far lower peak pressure as compared to a modern heavy duty diesel engine with compression ratio of around 14 to 17:1. Also, the modern multi weight moror oils were not available at the time.
Graph 7. Average lubricant film support pressure (atm) @TDC for different liner speeds and compression ring profiles.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 shows the general side view of the cylinder of the rotating sleeve engine. Note that clearances have been exaggerated for clarity.
FIG. 2 shows a detail of the sleeve driving mechanism
FIG. 3 shows the means of alternating the magnitude of the sleeve speed.
FIG. 4 shows the way adjacent sleeve gears engage each other.
FIG. 5 shows the sleeve/cylinder head sealing mechanism
FIG. 6A shows a conventional ring profile. The drawing is exaggerated for clarity. Note that profile is curved rather than angular as shown in the figure.
FIG. 6B shows the new ring piston profile for the rotating sleeve engine. Again, the drawing is exaggerated for clarity and profile is curved rather than angular as shown in the figure.
FIG. 7 shows the sleeve driving mechanism for a 4 cylinder rotating sleeve engine.
FIG. 8 shows a top view and two cross sections of a section of the new piston ring profile.
FIG. 9 shows sections the conical seal from three different views.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 (clearances have been exaggerated for clarity), there is shown one of the cylinders of a four stroke internal combustion engine with a rotating sleeve 1 that is supported by two journal bearings 2 . The intake of the fresh charge (or fresh air in the case of a Diesel) and exhaust of the combustion products are accomplished via conventional poppet valve arrangement (not shown) which are located in the cylinder head 3 . Thus, unlike typical sleeve valve engines, the motion of the liners is independent of valve timing and can be optimized for friction and wear minimization. A flange 4 on the upper part of the liner transfers the thrust loads to the cylinder head 3 and the block 5 . Furthermore, the flange reinforces the upper part of the sleeve preventing or minimizing the sleeve expansion due to high cylinder pressure that occur when the piston is in proximity to TDC. A piston 34 is fitted within the rotating sleeve and is connected via a connecting rod (not shown) to the crankshaft (not shown). The piston 34 is equipped with a compression ring 35 pinned on the piston to prevent its rotation, scraper ring 36 , also pinned on the piston, and oil control ring 37 . A set of pressure activated sealing devices 6 are installed on the upper part of the sleeve to prevent high pressure combustion gases from entering the space between the liner and the block. In FIG. 1, one pressure activated seal 6 is shown. This is a compression ring with spring load against the outside of its groove machined into the head 3 and also spring load against the flange 4 . The journal bearings 2 and 3 that support the sleeve are supplied with pressurized oil from the oil pump lubricating the bearings via oil passage 7 that is machined in the block. The clearance for these bearings is within the range for typical journal bearings of about 0.002 to 0.004 inches. The diameter to length ratio for the journal bearings is at typical values between 3 and 4. The upper bearing is located as high as possible, close to the flange. The location of the second bearing is not so strictly defined, but its centerline is at a level well bellow the middle of the piston stroke. Lubricant leakage from these journal bearings fills up the space between the liner and the block 8 and also lubricates the sealing device 6 and the flange 4 which acts as thrust bearing. The oil that surrounds the liner the space 8 will remove part of the excess heat from the engine. In fact, the motion of the liner will enhance heat transfer from the liner to the oil. The flange 4 can be provided with pads as on hydrodynamic thrust bearings in order to promote hydrodynamic lubrication pressures. The excess lubricant is removed by oil return passages 9 and 10 and by direct leakage back to the oil pan. Referring to FIG. 2, the sleeve 1 is equipped with a gear 11 that engages gear 12 which is connected to shaft 13 . Shaft 13 is driven by gear 15 attached to the shaft 13 . Gear 15 engages gear 14 which is part of the crankshaft 38 (shown only partially). As explained in previous sections, the final gear transmission ratio between the crank gear 14 and the sleeve 1 is very important for friction and wear consideration and can be optimized for different applications. This can be accomplished by changing the ratio of teeth gears 14 , 15 , 12 and 11 .
Alternative Embodiment: Unpinned Compression Ring
In the present alternative embodiment, the ring is not pinned in its piston groove. However, when the high cylinder pressure take place during compression, the friction between the lower piston groove will prevail preventing the ring's rotation. The benefit of this is the rotation of the rings at other parts of the stroke will maintain the groove clean and free of combustion deposits.
Alternative Embodiment: Alternating Sleeve Speed
The liner motion can be continuous (constant angular speed for a given crankshaft speed) for simplicity or with alternating value for this alternative embodiment. In the second case (alternative embodiment), a mechanism alternates the magnitude (but not the direction) of the liner angular velocity to a higher magnitude at the portion of the cycle when the piston is in proximity to a dead center. However, when the piston is around the mid portion of the stroke where hydrodynamic lubrication would exist anyway, the liner slows down for frictional savings. This is achieved preferably by using the Geneva wheel concept. The shaft 13 of FIG. 2 is broken up in two parts as shown in FIG. 3 . Wheel 16 is connected to the part of the shaft that is connected to the crankshaft, and rotates at constant speed for a given crankshaft speed. Also, wheel 16 is equipped with four pivots that engage the slots of wheel 17 that is connected to the part of the shaft that drives the gear 12 and thus the sleeve. Simple kinematics can show that the resulting speed of wheel 17 is alternating between a high value (pivot of wheel 16 is at its closest to the center of wheel 17 ) and a low value (pivot of wheel 16 is at its farthest location from the center of wheel 17 ). The number of teeth between gears 14 and 15 need to have a ratio of 1:2 in order to have the speed alternation in phase with piston motion. However, the ratio of teeth between gears 11 and 12 can be still altered arbitrarily in order to achieve any peak sleeve speed required at a given crankshaft speed. In the alternating sleeve speed embodiment, the sleeve thickness needs to be A the minimum possible in order to reduce the inertia loads on the driving mechanism. If carbon steel is to be used for the sleeve material, for SI and diesel engines, this thickness should be around {fraction (1/16)} and {fraction (3/16)} of an inch respectively. Note that when the typical peak pressures for each type of engine is applied to a sleeve of infinite length with the corresponding thickness, the elastic deformation is of the same order as a typical journal bearing clearance. However, the flange at the top of the sleeve will minimize that deformation to a much lower number. When the area of the sleeve that is surrounded by the lower journal bearing is exposed to cylinder gas pressure, the pressure is dissipated due to gas expansion to very low value.
Alternative Embodiment: Driving Mechanism for Multi-Cylinder Engines
In an alternative embodiment of the invention applied in a multi cylinder engine, gears are installed on the outside of the sleeve surface as shown in FIGS. 4 and 7 and mesh with the sleeves of neighboring cylinders eliminating the need for individual driving mechanisms. Gear 18 (which is identical to gear 11 as shown in FIG. 2) is bolted or press fitted on rotating sleeve 1 , while a similar gear 19 is attached to the neighboring sleeve 20 . The two gears are meshed through a slot machined on the block 5 . FIG. 7 shows this embodiment as applied to a 4 cylinder engine. Crankshaft 38 , supported by main bearings (not shown), is equipped at the left end with gear 14 that transfers mechanical energy to the gear 11 of sleeve 1 of cylinder #1 (#1 refers to the unit to the far left of the Figure) via shaft 13 . Gear 19 is attached to sleeve 20 of cylinder #2 and meshes with gear 18 (which is the same part as 1). The sleeve 20 of cylinder #2 similarly engages the gear of sleeve 41 of cylinder #3, etc. The above driving method is particularly attractive, if the constant sleeve speed embodiment is chosen, or if the alternating sleeve speed is to be used on a four cylinder engine (or in any in-line engine with a flat crankshaft design) where all pistons reach a dead center at the same time. With this design, only one driving mechanism transferring mechanical energy from the crank to the sleeves needs to be installed, and the sleeve motion propagates to all cylinders. FIG. 7 illustrates a typical 4 cylinder engine crankshaft of the “flat” design which means that all the connecting rod bearing centers are on one plane. As a result, all cylinders reach a dead center simultaneously. Pistons 39 and 40 of cylinders 1 and 4 respectively are shown at the bottom dead center (BDC) position while the pistons (not shown) of cylinder #2 and #3 are at TDC. Note that the instant shown in FIG. 7 is the part in the engine cycle where the maximum sleeve speed is reached if the alternating speed embodiment is applied.
Alternative Embodiment: Conical Sealing Device
In an alternative embodiment, a conical pressure activated sealing device has been conceived. Referring to FIG. 5, a conical ring 21 fits on an also conical groove 22 machined on the cylinder head 3 . Just like typical compression rings, that seal also has an open end and the diameter when uncompressed is a little larger than the groove it is supposed to fit in. Therefore, when forced into groove 22 , the spring force developed forces it against the outside wall of groove 22 . Due to the inclined surfaces, a spring load develops between the lower surface of ring 21 and the upper flat surface of the rotating sleeve. When large pressures due to combustion are developed within the cylinder, the ring 21 is further forced against the above surfaces intensifying the seal. The ring 21 could be held stationary (pinned) with respect to the cylinder head 3 and slide against the upper part of the rotating sleeve or be held stationary with respect to the sleeve and rotate with respect to the cylinder head. The presence of lubricant and continuous rotation are ideal for hydrodynamic lubrication. Again, part of the sliding surface can be provided with pads Oust like a hydrodynamic thrust bearing and similar to the proposed compression ring design) to promote the formation of hydrodynamic lubrication. FIG. 9 shows the design of the conical seal with pads at the location appropriate when the seal is pinned on the cylinder head and slides in respect to the sleeve's flange. 45 shows an overall three-dimensional sketch of a section of the seal with the pads 46 imbedded in order not to compromise the sealing. 47 is a side view with the pads 46 shown with hidden lines. 46 is a view of the lower surface with pads 46 clearly visible. The depth of these pads is exaggerated in FIG. 9 for clarity. Note that the simulations discussed above also apply for the lubrication of the sliding surface of conical sealing ring of FIG. 5 . However, due to the ring's location (further from the axis of rotation), this ring will enjoy a slightly higher sliding speed.
Alternative Embodiment: Sealing for High Peak Cylinder Pressure
The following embodiment is particularly desirable for an engine that develops high combustion pressures (i.e. turbocharged diesel engine). In such an engine, the cylinder sealing is more critical. Therefore, referring to FIG. 5, an additional compression ring 23 is fitted on groove 24 machined on the flange of the rotating sleeve. Any combustion gasses that escape the main conical seal 21 are trapped by ring 23 . Since ring 23 isolates the conical ring 21 from oil coming from the area 8 (area between sleeve and cylinder), an additional oil supply 25 is provided to lubricate the conical seal as well as the interface of the upper part of the flange and cylinder head which acts as thrust bearing. A similar oil passage to 25 is provided on the opposite side and acts as oil return.
Alternative Embodiment: Adjusted Compression Ring Profile
Hydrodynamic lubrication requires some form of converging surfaces, in order for lubricant pressures to form and support the normal load. When the piston is at top dead center and the only motion that occurs is due to liner rotation, there is no apparent converging surface (the surfaces are parallel). However, in reality the surface irregularities of the honed rotating liner provide minor converging (a phenomenon called micro-hydrodynamic lubrication). However, in the following alternative embodiment, the ring profile can be adjusted in order to create converging surfaces just due to ring rotation without relying on the surface irregularities and thus reducing the necessary rotation for fully hydrodynamic lubrication. Referring to FIG. 6A, the conventional ring profile 49 is made out of the following portions. A flat portion 26 that acts as a sealing surface between the liner and the ring. Wedges 27 and 28 act as converging surfaces during the up and down motion respectively to promote formation of hydrodynamic pressure. Please note that the drawing has been exaggerated for clarity and wedge shape is so small that cannot be seen by the naked eye. Also, the shape is actually curved rather than angular as shown in FIG. 6 . The new ring profile 50 (FIG. 6B) still maintains a flat portion 29 and is also provided with similar wedges at either edge 30 and 31 . However, the depth of these wedges changes in the peripheral direction creating wedges in that direction as well. When the minimum wedge depth is reached, the same pattern is repeated. FIG. 8 shows the top view 42 of a section of the new compression ring. Two cross sections, 43 and 44 are also shown in order to demonstrate the variation of the wedge depth. The result is that converging surfaces in the direction of sleeve rotation are effectively created. Thus, the pressure support of the ring is increased for a given liner rotational speed. This embodiment is particularly desirable for diesel engines where the peak cylinder pressure is very high. Simulations show that with the proposed ring profile, the lubricant pressure can be indeed dramatically increased even with a relatively large film thickness reaching the magnitude of typical peak cylinder pressure for heavy duty diesel engines at full load. Note that the proposed ring profile increases the flat portion of the ring improving sealing and increasing the effectiveness of squeeze film lubrication at dead center. Part of the converging surface that enhances hydrodynamic lubrication due to up and down motion has been sacrificed. However, results from the models by Tian and coworkers (1996), Lawrence (1988) as well as several experimental studies indicate that under most operating conditions, there is more than sufficient film thickness at mid-stroke for hydrodynamic lubrication. Furthermore, since at least some liner rotation will be retained at mid-stroke, the converging surfaces at the peripheral direction will remain active and substitute for the overall reduction of the barrel shape.
Alternative Embodiment: Adjusted Ring Profile Applied to Conical Ring
In another alternative embodiment, a profile using the above concept can is applied on the pressure activated sealing devices. In other words, ring 21 and 23 (FIG. 5) have pads machined along their sealing surface in order to promote hydrodynamic lubricant pressure build up and avoid metal to metal contact. The pads are imbedded in the sliding surface of ring in order to allow tight sealing clearance in the rest of the surface. Note that the above simulations also apply for the lubrication of the lower flat sliding surface of conical sealing ring of previous embodiments. However, due to the ring's location (further from the axis of rotation), this ring will enjoy a slightly higher sliding speed. In addition to the surface irregularities, pads may be necessary to increase the film thickness when high gas pressure is encountered. Those pads can be similar in shape to typical hydrodynamic thrust bearings, but may have to be imbedded in the flat surface in order not to interfere with the sealing action. Also note that squeeze film lubrication will apply on this ring as well since the film thickness will be high before the gas pressure is raised.
Alternative Embodiment: Turbocharged Diesel Engine
The following alternative embodiment describes the invention as applied to a turbocharged diesel engine with the maximum torque (and thus maximum peak cylinder pressure) at 1200 rpm. The typical maximum pressure at the peak torque speed at full load for such an engine is about 100 atm. Referring to graph 7, the necessary liner speed in order to completely protect the liner and rings from metal to metal contact is around 3.5 m/s, if the proposed compression ring profile is to be used., For a 5.5 inch bore heavy duty engine, the resulting sleeve speed is 478 rpm. In the constant speed liner case, the gear ratio needs to be such that the gear 11 (FIG. 7) attached on sleeve will spin at 478 rpm when crank gear 14 spins at 1200. Thus, the necessary condition for the number of teeth of gears 11 , 12 , 15 , and 14 is: n 14 · n 12 n 15 · n 11 = 478 1200
Alternative Embodiment: Diesel Engine with Alternating Sleeve Speed
As an alternative embodiment, the variable sleeve speed will be applied on the diesel engine of the previous embodiment. In this case, the maximum instantaneous sleeve speed occurring when the piston is at a dead center needs to be 478 rpm. Simple kinematics of wheels 16 and 17 will give the required speed of wheel 17 and 16 (FIG. 3 ), and the corresponding gear ratios in order to achieve the liner speed of 478 rpm. The geometry of wheels 16 and 17 (distance of the two centerlines and radius of pivots on wheel 16 ) will be designed such that the required speed variation will be achieved. Note that the minimum speed should be chosen by two constraints. One is that the sleeve speed should not fall bellow a minimum necessary to retain the hydrodynamic film that support the sleeve. This minimum depends on the design of these bearings, viscosity lubricant used, the stroke to connecting rod length ratio and the cylinder pressure when the minimum speed occurs. The second is that an extreme speed variation could lead to excessive inertia loading on the driving mechanism which in turn will demand larger size gears to deal with the alternating inertia load.
Alternative Embodiment: Spark Ignition Engine
In the following alternative embodiment, the current invention is applied to a spark ignition engine, with a peak torque at 3000 rpm and a bore of 3.5 inches. The peak cylinder pressure at 3000 rpm is 50 atm. Referring to Graph 7, the required sleeve speed for full metal to metal protection at TDC is about 1.7 m/s. The corresponding sleeve speed is 365 rpm. For the constant sleeve speed, the gear ratio selection will be such that at 3000 crankshaft rpm, the sleeve gear spins at 365 rpm. The number of gear teeth selection is as above. For the alternating liner speed alternative embodiment, the maximum sleeve speed when the piston is at a dead center is 365 rpm.
Alternative Embodiment: Lubricant as Engine Coolant
In another alternative embodiment, the lubricant surrounding the rotating sleeve 1 in space 8 (FIG. 1) can be used as the sole coolant of the engine. The flow rate needs to be sufficient to remove all excess heat from the cylinder walls. In conventional water cooled engines, water jackets are machined or cast in the cylinder heads in which water flows for cooling. In this embodiment, those passages are filled with lubricant. The oil pump powers the lubricant flow through these cylinder head passages removing excess heat. The whole oil flow rate is also pumped through an oil cooler of sufficient capacity in order to dissipate this waist heat into ambient air. Thus, the water pump, water radiator, and coolant hoses are replaced with a larger oil cooler and oil pump in order to compensate for the extra complexity of the system. The benefit of this embodiment is that the incremental cost of the rotating sleeve engine in respect to a conventional engine ir reduced. | An internal combustion engine is provided including at least one cylinder having a conventional valvetrain. The valvetrain consists of at least one camshaft, at least one intake poppet valve per cylinder activated by the camshaft and at least one exhaust valve per cylinder activated by the camshaft as well. Rotably disposed within the engine block is a rotatable cylinder liner which is supported from the block with at least two journal bearings. A piston is mounted in each liner for reciprocating movement therein. A connecting rod connects each piston to a crankshaft converting the reciprocating motion to crank rotation. The sleeve rotates with the objective of improving the lubrication conditions of the piston rings and piston. The reduction in friction coefficient between the piston rings and liner at certain portions of the cycle will result in significant frictional benefits. The motion of the liner will result in continuous fluid lubrication which results in severe reduction of piston ring and liner wear. | 5 |
PRIOITY CLAIM
This patent claims priority from the earlier filed Hong Kong Patent Application No. 06112953.4 filed Nov. 24, 2006, by inventors Kai Chiu Wu, Ming Lu, and Chak Hau Pang.
TECHNICAL FIELD
This invention relates to light emitting assemblies having heat dissipating supports for reducing the operating temperature of the assembly.
BACKGROUND OF THE INVENTION
Light sources comprising assemblies of light emitters such as light emitting diodes (LEDs) are finding increasing application in mass production applications because of their high efficiency and long life. One such application is light sources for replacing florescent and incandescent lights and the like.
High output LEDs, particularly when a large number are used on a common support, produce a significant amount of heat. If elevated temperatures are then produced, the life of the LEDs is reduced. In practice, it is desirable that the LED be placed into contact with heat dissipation surfaces to effectively cool the LED. One such arrangement is described in the applicant's pending application No. 60/830,110. While this device performs satisfactorily, it will be appreciated that there is an ongoing need for an improved assembly capable of mounting a large number of light emitters and one which can be produced economically. The assembly should include a great deal of heat transfer potential in addition to providing a means for further incorporating the light emitter into the circuitry of an overall lighting assembly.
DISCLOSURE OF THE INVENTION
According to one aspect of the invention there is provided a light emitter assembly, comprising:
a substrate carrying a plurality of light emitters, and
a housing including mutually connected thermally conductive ribs spaced apart for air flow therebetween, the substrate supported generally transversely between the ribs, the ribs abutting the light emitters or substrate for thermally connecting the light emitters or substrate to the housing.
In another aspect the invention provides a light emitter assembly, comprising:
first and second substrates carrying first and second pluralities of light emitters respectively,
a housing including mutually connected metal ribs spaced apart for air flow therebetween, both substrates extending generally transversely between the ribs with the second substrate spaced apart from the first substrate for air flow therebetween, the ribs having shoulders abutting the light emitters or substrates and thermally connecting the light emitters to the housing.
Preferably the substrates are formed of sheet material, each substrate having a respective peripheral edge and respective planar inner and outer faces, the outer faces being aligned generally parallel, the ribs surrounding the peripheral edges of the substrates, the first substrate having a recess such that light emitted outward from each of the second plurality of light emitters in a direction perpendicular to the outer faces passes through the recess and is not occluded by the first substrate.
Preferably a mounting portion of each outer face abuts each light emitter, and one of said shoulders abuts a portion of the inner face opposite each mounting portion.
Preferably the ribs extend radially relative to a central axis of the housing and are mutually connected at the longitudinally inner ends thereof. In a preferred embodiment the ribs are also mutually connected by a ring portion at the longitudinally outer ends thereof.
The first and second pluralities of light emitters are preferably mounted substantially upon respective first and second pitch circles centred on the central axis, the diameter of the first pitch circle exceeding the diameter of the second pitch circle, the light emitters of the first plurality being circumferentially offset relative to the light emitters of the second plurality.
The substrates are preferably ring shaped, most preferably being formed from planar sheet material.
The assembly preferably further includes at least one generally transversely extending metal heat dissipation member connected to the ribs intermediate the inner and outer ends. Preferably the heat dissipation member is slotted to receive and engage each of the ribs.
The housing preferably has a substantially frustoconical periphery defined by the circumferentially spaced radially outermost edges of the ribs.
In another aspect the invention provides a light emitter assembly, comprising:
first and second substrates carrying first and second pluralities of light emitters respectively,
a housing including mutually connected metal ribs spaced apart for air flow therebetween and extending between an inner and an outer end of the housing, wherein
the substrates extend generally transversely between the ribs, the second substrate being spaced apart inwardly from the first substrate for air flow therebetween, the first substrate having a recess such that light emitted outward from each of the second plurality of light emitters in the longitudinal direction faces passes through the recess and is not occluded by the first substrate, and the ribs abutting the light emitters or substrates for thermally connecting the light emitters to the housing.
This invention provides an light emitter assembly having satisfactory light dispersion or radiation pattern and a simple design with a reduced number of parts to minimize manufacturing costs. Heat is efficiently dispersed into the housing and the spacings between the ribs of the housing, as well as between the substrates themselves, enhance the heat transfer rate through natural convection in different orientations of the assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
FIG. 1 is a pictorial view of an light emitter assembly of the present invention;
FIG. 2 is an exploded view of the assembly of FIG. 1 ;
FIGS. 3-5 are outer end views of substrates of the assembly of FIG. 1 ;
FIG. 6 is an end view of the housing of the assembly of FIG. 1 ;
FIG. 7 is an enlarged section illustrating the connection between a rib and substrate;
FIG. 8 is a section along line AA of FIG. 6 showing an outer substrate in dashed outline;
FIG. 9 is a section along line BB of FIG. 6 showing an inner substrate in dashed outline;
FIG. 10 is a section along line CC of FIG. 6 showing an intermediate substrate in dashed outline, and
FIG. 11 is detail of the electrical connection between the substrates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 , a light emitter assembly 100 includes three light emitter substrates 1 , 2 , 3 and two heat dissipating members 4 , 5 which are stacked in a housing 6 . The components 1 - 5 are substantially parallel, extending transversely relative to a central longitudinal axis 7 . In the embodiment illustrated the LED substrates 1 , 2 , 3 and heat dissipating members 4 , 5 are in a generally planar ring shape, but it will be understood that different shapes will be equally applicable depending upon the required application of the assembly.
Each LED substrate 1 , 2 , 3 has an outer surface 1 a , 2 a , 3 a and an opposing inner surface 1 b , 2 b , 3 b . Four LEDs 8 , 9 , 10 are mounted on the respective outer surfaces 1 a , 2 a , 3 a equally angularly spaced on respective pitch circles 11 , 12 , 13 centred on the central axis 7 and emitting light substantially parallel to the axis 7 .
The LEDs on the three substrates 1 , 2 , 3 are offset radially, the pitch circle diameter 11 exceeding pitch circle diameter 12 , and pitch circle diameter 12 exceeding pitch circle diameter 13 . The LEDs of adjacent pairs of substrates 1 , 2 and 2 , 3 are circumferentially offset by 45°. Substrate 1 has a central recess 14 with four indentations 14 a - 14 d circumferentially offset by 45° from the LEDs 8 for registration with the LEDs 9 , such that light emitted outward from each of the LEDs 9 is not occluded by the substrate 1 . Likewise, substrate 2 has a recess 15 with four equally angularly spaced indentations 15 a - 15 d for axial registration with the LEDs 10 . In this manner the LEDs 8 , 9 , 10 are not blocked by each other or the substrates. Alternatively, transparent windows or substrates may be used for enhancing light emission efficiency in alternate embodiments.
In the embodiment shown, each substrate 1 , 2 , 3 is formed with a thermally conductive material such as metal-core printed circuit board (MC-PCB) or ceramic based substrate, for assisting heat distribution in each substrate. The MC-PCBs or ceramic based substrates are patterned to provide electrical paths (not shown) thereon for powering the LEDs as generally understood by those skilled in the art.
Referring to FIGS. 6-10 , the housing 6 is a one-piece metal component, for example, of die-cast aluminium or magnesium for good thermal conductivity. The housing 6 generally comprises substantially planar and radially aligned ribs 16 , 17 , 18 elongated to join a disc-shaped inner portion 19 to an outer ring 20 .
Four ribs 16 are equally angularly spaced, each having a radially outermost edge 21 , an inner shoulder 22 and an outer shoulder 23 . Each of the shoulders 22 , 23 has a respective transversely aligned shoulder surface 22 a , 23 a . The substrate 1 abuts the shoulder surface 23 a below the LEDs 8 and the substrate 3 abuts the shoulder surfaces 22 a below the LEDs 10 .
Angularly offset from ribs 16 by 45° are four ribs 17 that are also are equally angularly spaced. Each rib 17 has a radially outermost edge 24 , an inner shoulder 25 and an outer shoulder 26 . Each of the shoulders 25 , 26 has a respective transversely aligned shoulder surface 25 a , 26 a . The substrate 1 abuts the shoulder surfaces 25 a and the substrate 2 abuts the shoulder surfaces 26 a below the LEDs 9 .
FIG. 7 illustrates the mounting portion 27 of outer face 2 a which abuts each LED 9 , by way of an illustration of the way all the heat dissipating ribs 16 , 17 are fixed adjacent a respective LED. The shoulder surface 25 a abuts the inner face 2 b opposite each mounting portion 27 and is fixed by a thermally conductive adhesive for allowing efficient thermal connection between the ribs and the substrates. Optionally mechanical fasteners may also be used for joining the substrates and ribs.
Eight ribs 18 are equally angularly spaced, each having a radially outermost edge 35 , and shoulders 30 - 34 . The shoulders 30 , 31 , 32 abut the substrates 1 , 2 , 3 respectively and the shoulders 33 , 34 abut the metal members 4 , 5 and are likewise preferably fixed by thermally conductive adhesive. Each member 4 , 5 extends transversely and is radially notched for receiving the ribs 16 , 17 , 18 . With the substrates 1 , 2 , 3 and members 4 , 5 physically spaced apart by a gap, more efficient thermal dissipation from the substrate to the environment, for example air surrounding the substrates, can be achieved. With the substrates thermally connected, heat will be transferred from a substrate of a higher temperature to a substrate of a lower temperature, and therefore more even thermal distribution among the substrates can be achieved.
The ribs 16 , 17 , 18 are splayed apart in the longitudinal direction, the housing 6 having a substantially frustoconical periphery defined by the circumferentially spaced radially outermost edges 21 , 34 , 35 of the ribs 16 , 17 , 18 . Fixed to the inner portion 19 is a hollow mounting fitting 37 which receives the electrical circuit 38 for supplying power to the LEDs 8 , 9 , 10 .
Apertures 38 , 39 in the substrate 1 are positioned between each LED 8 and are axially aligned with recesses 40 , 41 in the substrate 2 for enhancing air flow through the substrates. The apertures 38 - 14 and the spacing between the ribs 16 - 18 provides satisfactory air flow and consequently enhance the thermal dissipation efficiency, regardless of the orientation of the assembly 100 .
With the axial assembly of the substrates 1 , 2 , 3 into the housing, axially aligned pin-and-socket type connectors 42 , 43 , as shown in FIG. 11 may provide the electrical connection between the substrates 1 , 2 , 3 .
Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof. | A plurality of disc-shaped substrates carry light emitters and are axially stacked, spaced apart, in a metal housing to dissipate the heat produced by the light emitters. The housing comprises mutually connected elongate planar ribs that abut the light emitters or substrates for thermally connecting the light emitters to the housing. The ribs have shoulders. The substrates are received between the ribs and abut the shoulders. The shoulders are positioned proximate each light emitter in intimate contact with the substrate for efficient heat dissipation. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a light source unit and a projector apparatus equipped with the light source unit, and more particularly to a light source unit miniaturized without decreasing the utilization efficiency of light from a light source and a projector apparatus equipped with the light source unit.
2. Description of the Related Art
A projector apparatus is configured to display an image on a screen by making the light that has outgone from a light source unit be incident into a mirror tunnel to make the light having a uniform intensity distribution after making the light pass through a color wheel, and by projecting the light with the light quantity being switched at each pixel with a micro-mirror device, a liquid crystal display device or the like.
As shown in FIG. 9 , a light source unit 50 is composed of a light source 51 radiating light, a convex lens 52 , which is disposed on an optical axis K for condensing the light emitted form the light source 51 , and a mirror tunnel 53 , into which the light that has outgone from the convex lens 52 is made to be incident (see JP Hei 06-51401A).
The light source 51 is composed of a reflector 54 and a lamp 55 inserted into the reflector 54 . The lamp 55 is composed of a bulb 56 and electrode introducing units 59 , and the lamp 55 is inserted so that the bulb 56 may be located in the reflector 54 . In addition, the color wheel is omitted in FIG. 9 .
Here, a part of the light that has been emitted from the bulb 56 and has been reflected by the inner wall of the reflector 54 strikes the electrode introducing unit 59 , and the light quantity of the light is attenuated. Moreover, the convex lens 52 cannot sufficiently radiate the light reflected by the reflector 54 onto the incidence plane 53 a of the mirror tunnel 53 .
Accordingly, in order to secure a certain light quantity, it becomes necessary for the light source unit 50 to have a size equal to a certain size or more, and a projector apparatus having the light source unit 50 built therein has a tendency to become large in size. Consequently, the projector apparatus is not always easy to carry and to install.
Although the size of a light source unit is more preferable to be smaller from the viewpoint of miniaturizing the whole body, it has been necessary for the size of the lamp of the light source unit to be a certain size or more from the viewpoint of securing a light quantity.
SUMMARY OF THE INVENTION
A preferable aspect of the present invention is a light source unit including: a reflector having an opening for housing a lamp and an opening for radiating light, the reflector having an inner surface subjected to mirror surface working to be shaped in a polynomial surface; a light source equipped with a bulb emitting light and an electrode introducing unit guiding an electrode to the bulb, the bulb being inserted into the reflector from the opening for housing the lamp and being disposed so that a focus position of the light emitted from the bulb and reflected by an inner wall of the reflector is not located on the electrode introducing unit; and a condenser lens condensing the light emitted from the reflector, the condenser lens disposed so as to be located on an optical axis of light emitted from the light source.
Moreover, another preferable aspect of the present invention is a projector apparatus including: a light source unit composed of a reflector having an opening for housing a lamp and an opening for radiating light, the reflector having an inner surface subjected to mirror surface working to be shaped in a polynomial surface, a light source equipped with a bulb emitting light and an electrode introducing unit guiding an electrode to the bulb, the bulb being inserted into the reflector from the opening for housing the lamp and being disposed so that a focus position of the light emitted from the bulb and reflected by an inner wall of the reflector is not located on the electrode introducing unit, and a condenser lens condensing the light emitted from the reflector, the condenser lens disposed so as to be located on an optical axis of light emitted from the light source; a mirror tunnel guiding light that has outgone from the condenser lens; a lens condensing light that has outgone from the mirror tunnel; a micro-mirror device receiving light that has outgone from the lens to project an image; and a projector lens expanding the image projected from the micro-mirror device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the inner part of a projector apparatus according to an embodiment of the present invention;
FIG. 2 is a schematic configuration diagram of an optical system according to the projector apparatus of the present embodiment;
FIG. 3 is a schematic sectional view of a light source unit;
FIGS. 4A , 4 B and 4 C are schematic views showing a lamp used for the present invention;
FIG. 5 is a schematic perspective view of a condenser lens according to the present embodiment;
FIG. 6 is a sectional view taken along a line VI-VI of the condenser lens shown in FIG. 5 ;
FIG. 7 is a schematic front view of the lens surface on the light source side of the condenser lens according to the present embodiment;
FIG. 8 is a schematic view showing a positional relation between the members constituting the light source unit; and
FIG. 9 is a sectional view of a conventional light source unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, an embodiment of the present invention is described by reference to the drawings. However, the range of the invention is not limited to the shown example.
FIG. 1 is a top view showing the inner part of a projector apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the optical system according to the projector apparatus of the present embodiment. FIG. 3 is a schematic sectional view of a light source unit. In addition, the illustration of a color wheel 20 is omitted in FIG. 3 .
As shown in FIG. 1 , a projector apparatus 1 is provided with a case 2 . A power source substrate 3 for controlling the whole body of the projector apparatus 1 is disposed in the inner part of the case 2 . On the power source substrate 3 a not shown power source is attached. Near the central portion in the case 2 , a light source unit 4 controlled by the power source substrate 3 is disposed.
As shown in FIGS. 2 and 3 , the light source unit 4 is composed of a light source 5 and a condenser lens 6 . As shown in FIG. 3 , the light source 5 is composed of a reflector 9 and a lamp 10 housed in the reflector 9 .
The reflector 9 is formed into a polynomial surface shape. The polynomial surface shape of the reflector 9 is a form expressed by the formula obtained by substituting a value shown in Table 1 for each parameter of the following Formula (1).
TABLE 1
(1)
z
=
cr
2
1
+
1
-
(
1
+
k
)
c
2
r
2
+
c
1
r
+
c
2
r
2
+
c
3
r
3
+
c
4
r
4
⋯c
10
r
10
DIAMETER OF OPENING FOR
33.12
RADIATING LIGHT (mm)
DIAMETER OF OPENING FOR
11
HOUSING LAMP (mm)
CONIC CONSTANT: k
−0.47973
CURVATURE: c
0.0837149
COEFFICIENT: c1
9.29227E−02
COEFFICIENT: c2
−3.764339E−02
COEFFICIENT: c3
7.347004E−03
COEFFICIENT: c4
−5.758458E−04
COEFFICIENT: c5
−1.368030E−06
COEFFICIENT: c6
2.231387E−06
COEFFICIENT: c7
−2.921644E−08
COEFFICIENT: c8
−1.982415E−09
COEFFICIENT: c9
−2.136231E−10
COEFFICIENT: c10
1.042357E−11
In Formula (1), the letter z denotes an axis in an optical axis direction (the traveling direction of light is supposed to be positive); the letter c denotes a radius of curvature; the letter k denotes a conic constant; and the letter r (mm) denotes the length of a perpendicular line when the perpendicular line is let fall from the edge portion of an opening for radiating light 11 , which will be described later, to the optical axis K.
Moreover, the opening for radiating light 11 is formed on the reflector 9 for making light outgo. Furthermore, an opening for housing a lamp 12 is also formed at the base of the reflector 9 , and the lamp 10 is housed from the opening for housing a lamp 12 .
As shown in FIG. 4A , the lamp 10 is composed of a bulb 13 making light outgo and electrode introducing units 14 provided on both the ends of the bulb 13 in the longitudinal direction thereof for introducing electrodes into the bulb 13 . Moreover, in the bulb 13 , an arc 15 carrying out discharges is provided. The bulb 13 is disposed near the opening for housing a lamp 12 in the reflector 9 so that the focus position of emitted light emitted from the bulb 13 to be reflected by the inner wall of the reflector 9 may be formed at a position farther than the electrode introducing unit 14 on the side of the traveling direction of the emitted light.
As a concrete shape of the bulb 13 used for the present invention, for example, the following shape can be cited.
First, as shown in FIG. 4B , an ellipse A having a conic coefficient of −0.91508, the radius of curvature of 4.175964 mm, a semimajor axis of 49.17239 mm and a semiminor axis of 14.32976 mm is located so that the major axis L of the ellipse A may cross at right angles with the optical axis K. At this time, the optical axis K is disposed so that the optical axis K may cross at right angles with the major axis L of the ellipse A at a position distant by 5.25 mm from a point Q at one end on the major axis L of the ellipse A to the side of a point R at the other end on the major axis L of the ellipse A (hereinafter, the point where the optical axis K crosses at right angles with the major axis L of the ellipse A is referred to as a “point S”).
Next, an ellipse B is disposed so that the central point U of the ellipse B may be located at a position distant by 24.77409 mm from the central point T of the ellipse A on the side of the point Q on the major axis L and so that the minor axis N of the ellipse B may be parallel to the minor axis M of the ellipse A. The ellipse B has a conic coefficient of −0.85721, the radius of curvature of 110047 mm, a semimajor axis of 21.7811 mm and a semiminor axis of 8.230445 mm.
Next, the ellipses A and B are rotated around the optical axis K. Thereupon, a solid spindle C shown in FIG. 4C is formed by an arc O of the ellipse A, which is located nearer to the point Q than the optical axis K and rotates around the optical axis K.
The outer edge portion of the solid spindle C corresponds to the periphery of the bulb used for the present embodiment. Moreover, the space in the inside of a spindle D formed by the rotation of an arc P of the ellipse B, which is located nearer to the point Q than the optical axis K, around the optical axis K corresponds to the space in which the arc 15 is housed in the bulb.
Then, the shape of the space between the spindles C and D corresponds to the shape of a glass member for housing the arc, and the point S corresponds to the position of the arc housed in the bulb. By attaching the electrode introducing units 14 supplying electric power to the arc on both the ends of the bulb 13 , which has the shape mentioned above, in the longitudinal direction of the bulb 13 as shown in FIG. 4A , the lamp 10 used for the present invention is formed.
The condenser lens 6 is disposed in the traveling direction of the light that has outgone from the opening for radiating light 11 of the reflector 9 . The shape of the condenser lens 6 is not limited as long as the condenser lens 6 can sufficiently condense the light that has outgone from the opening for radiating light 11 to make the condensed light outgo into the traveling direction of the light. An example of a lens capable of being used as the condenser lens is shown in the following.
FIG. 5 is a schematic perspective view of an example of the condenser lens 6 , and FIG. 6 is a sectional view taken along the line VI-VI of the condenser lens 6 shown in FIG. 5 .
As shown in FIGS. 5 and 6 , a lens surface 16 on the side on which the light that has outgone from the opening for radiating light 11 of the reflector 9 is radiated is formed into a concave, and the lens surface 16 is formed to be most depressed in the central portion of the lens surface 16 . Moreover, a lens surface 17 on the side from which the light of the condenser lens 6 outgoes is formed into a convex, and is formed so that the central portion of the lens surface 17 may evaginate. In addition, although the central portion of the lens surface 16 of the condenser lens 6 is formed so as to be depressed and the central portion of the lens surface 17 of the condenser lens 6 is formed so as to evaginate, the lens surface 16 may be simply formed into a concave and the lens surface 17 may be also simply formed into a convex.
The condenser lens 6 is disposed so that the lens surface 16 may be opposed to the opening for radiating light 11 of the reflector 9 of the light source 5 and the lens surface 17 may be opposed to the incidence surface 21 a of a mirror tunnel 21 , which will be described later. Moreover, the condenser lens 6 is disposed so that the center of the lens surface 16 and the center of the lens surface 17 may be located on the optical axis K.
The shape of the lens surface 16 on the side of the light source 5 of the condenser lens 6 and the shape of the lens surface 17 on the side of the mirror tunnel 21 are expressed by the formulae obtained by substituting each parameter of the following Formula (2) for a value shown in Table 2.
TABLE 2
(2)
z
=
cr
2
1
+
1
-
(
1
+
k
)
c
2
r
2
+
c
1
r
+
c
2
r
2
+
c
3
r
3
+
c
4
r
4
LENS SURFACE 16
LENS SURFACE 17
CONIC CONSTANT: k
−1
−1
RADIUS OF
INFINITY
INFINITY
CURVATURE: c
COEFFICIENT: c1
−8.124720E−01
1.535353E−01
COEFFICIENT: c2
1.777498E−01
−8.654634E−02
COEFFICIENT: c3
−2.406356E−02
−1.362107E−03
COEFFICIENT: c4
1.099373E−03
2.023045E−04
In Formula (2), the letter z denotes an axis in an optical axis direction (the traveling direction of light is supposed to be positive); the letter c denotes a radius of curvature; and the letter k denotes a conic constant. Moreover, the letter r (mm) denotes the length of a perpendicular line Z when the perpendicular line Z is let fall from a point V, which is a point on the edge portion of the condenser lens 6 , to the optical axis K, as shown in FIG. 6 .
The lens surface 16 on the side of the light source 5 of the condenser lens 6 can be divided into the range (hereinafter referred to as an “effective range”) that condenses radiated light to introduce the condensed light to the lens surface 17 on the side of the mirror tunnel 21 and the other range. For example, in case of a condenser lens having the radius of 10 mm, as shown in FIG. 7 , the effective range 19 is the range on the outside of the range within 1.5 mm from the central point X and on the inside of the range within 9 mm from the central point X. Then, the distance from a point W to the central point X is 3.4 mm, and the distance from the central point X to a point Y, where the optical axis K and the lens surface 17 are crossed with each other, is 6.51 mm.
As shown in FIGS. 1 and 2 , in the outgoing direction of light of the condenser lens 6 , the color wheel 20 , which converts the light that has outgone from the condenser lens 6 into each color of red (R), green (G) and blue (B), is disposed. The mirror tunnel 21 is disposed in the traveling direction of the light that has been transmitted through the color wheel 20 , and an image unit 22 for projecting an image on a screen is disposed in the outgoing direction of light of the mirror tunnel 21 . In addition, the color wheel 20 may be disposed on the side of the outgoing direction of light of the mirror tunnel 21 .
The color wheel 20 is a circular rotation plate, and is equipped with the color filters of a red (R) one, a green (G) one and a blue (B) one, which are arranged in the circumferential direction. The color wheel 20 is disposed so that the central axis of rotation is laterally shifted from the optical axis K.
The mirror tunnel 21 is a transparent rectangular column, and is provided to be arranged along the optical axis K. The mirror tunnel 21 introduces the incidence light from the incidence surface 21 a into the optical axis direction, making the incidence light carry out the total reflections thereof at the interface between the side surface of the mirror tunnel 21 and the outside air layer. Then, the mirror tunnel 21 makes the guided light outgo from the exit surface 21 b of the mirror tunnel 21 as a light flux having a uniform intensity distribution. In addition, a rectangular cylinder in which a reflection film is provided on the whole inner circumferential surface thereof may be used as the mirror tunnel 21 .
As shown in FIGS. 1 and 2 , the image unit 22 is disposed in the direction in which light is made to outgo from the mirror tunnel 21 . As shown in FIG. 2 , the image unit 22 is composed of, for example, a lens 23 irradiated by the light that has been made to outgo from the mirror tunnel 21 , a micro-mirror device 24 irradiated by the light that has been made to outgo from the lens 23 , and a projector lens 25 on which the light that has been reflected by the micro-mirror device 24 is projected.
The lens 23 projects the light that has been made to outgo from the mirror tunnel 21 on the micro-mirror device 24 . Although the lens 23 is illustrated as a single lens in FIG. 2 , the lens 23 may be composed of a plurality of lenses.
The micro-mirror device 24 forms each pixel of a display image by a plurality of micro-mirrors, and switches the light and darkness of the pixels by switching the inclination directions of these micro-mirrors to project the image. The micro-mirrors are formed of ultra-thin pieces of metal such as the pieces of aluminum, and each of the micro-mirrors has a vertical width and a horizontal width, each within a range of from 10 μm to 20 μm. Each of these micro-mirrors is formed on each of a plurality of mirror driving devices (not shown) such as CMOS's arranged in a matrix in row directions and column directions.
The projector lens 25 expands the reflected light from the micro-mirror device 24 to project the expanded light onto the screen (not shown). In addition, although the projector lens 25 is illustrated as a single lens in FIG. 2 , the projector lens 25 may be composed of a plurality of lenses.
As shown in FIG. 1 , a sirocco fan 26 making cooling air flow into the inside of the light source 5 in order to cool the light source 5 is disposed between the case 2 and the mirror tunnel 21 . Moreover, an axial flow fan 29 for exhausting the air that has been made to flow into the light source 5 is disposed in the direction of the opening for housing a lamp 12 of the reflector 9 .
Here, an example of the positional relation of the light source unit 4 used in the present embodiment is described. In addition, the above exemplified sizes of the reflector, the lamp and the condenser lens are used as those in the description here. FIG. 8 is a schematic sectional view of the light source unit 4 showing the positional relation of the members constituting the light source unit 4 . In addition, in order to clarify the positional relation, the illustration of the color wheel 20 is omitted in FIG. 8 .
The arc 15 is disposed so as to be located at a position distant from the base of the reflector 9 by 5.794 mm on the optical axis K. The condenser lens 6 is disposed so that the center of the lens surface 16 on the side of the light source 5 may be located at a position distant from the arc 15 by 33.34 mm. Moreover, the mirror tunnel 21 is disposed so that the distance from the arc 15 to the point where the incidence surface 21 a and the optical axis K cross at right angles may be 47.5 mm.
Next, the operation of the embodiment of the present invention is described.
When the projector apparatus 1 is driven, light is emitted from the bulb 13 of the light source 5 , and most of the emitted light is radiated onto the inner wall of the reflector 9 , on which mirror surface working is performed.
At this time, as shown in FIG. 3 , the bulb 13 of the light source 5 is disposed near to the opening for housing a lamp 12 in the reflector 9 so that the focus position of emitted light that has been emitted from the bulb 13 and has been reflected by the inner wall of the reflector 9 may be formed at a position farther than the end of the electrode introducing unit 14 on the side of the condenser lens 6 in the traveling direction of the reflected light. Consequently, most of the reflected light is radiated to the portions other than the central portion of the lens surface 16 of the condenser lens 6 . The light radiated into the effective range 19 in the light radiated onto the lens surface 16 of the condenser lens 6 is condensed before being radiated from the lens surface 17 into the color wheel 20 .
After the light that has been radiated into the color wheel 20 is converted into three colors of red, green and blue by the filter of each color of the red (R), the green (G) and the blue (B), respectively, the converted light is radiated onto the incidence surface 21 a of the mirror tunnel 21 . The light that has been incident into the mirror tunnel 21 is guided into the optical axis direction, being subjected to the total reflection at the interface between the side surface in the mirror tunnel 21 and the outside air layer as shown in FIG. 3 . Then, the guided light is radiated into the lens 23 after having been made to outgo from the exit surface 21 b.
The light flux of the light that has been radiated on the lens 23 is expanded by the lens 23 , and then the expanded light is radiated onto the micro-device 24 . Then, the light reflected by the micro-mirror device 24 is expanded by the projector lens 25 to be projected onto the not shown screen.
As described above, according to the present invention, because the focus position of the emitted light that has been emitted from the bulb 13 and has been reflected by the reflector 9 does not exist on the electrode introducing unit 14 , most of the emitted light does not strike the electrode introducing unit 14 of the lamp. Consequently, the emitted light does not attenuate to be radiated onto the lens. Thus, the loss of the emitted light can be reduced, and then the utilization efficiency of the emitted light emitted from the light source 5 can be improved. Consequently, it becomes possible to miniaturize the reflector 9 , and to miniaturize the whole body of the light source unit 4 in comparison with the conventional light source unit.
Moreover, because the light source unit 4 is miniaturized, the projector apparatus 1 , which installs the miniaturized light source unit 4 , can be miniaturized itself. | A light source unit and a projector apparatus secure a certain light quantity by improving the utilization efficiency of light, and thereby realize miniaturization. The light source unit includes a reflector having an opening for housing a lamp and an opening for radiating light, the reflector having an inner surface subjected to mirror surface working to be shaped in a polynomial surface, a light source equipped with a bulb and an electrode introducing unit guiding an electrode to the bulb, the bulb being inserted into the reflector from the opening and being disposed so that a focus position of the light reflected by an inner wall of the reflector is not located on the electrode introducing unit, and a condenser lens condensing the light emitted from the reflector, the condenser lens disposed so as to be located on an optical axis of light emitted from the light source. | 6 |
FIELD OF THE INVENTION
The present invention relates to cutting a label media. In one aspect, the invention relates to a method and system for automatically controlling plotter cutting depth when plotter cutting a label media. In another aspect, the present invention relates to a method and system for plotter cutting a label media.
BACKGROUND OF THE INVENTION
Electronic label printing machines are often used to generate adhesive labels having images (e.g., indicia, graphics, art, specialized instructions, warnings, slogans, advertising, etc.) to facilitate identification, tracking and pricing of goods. Such label printers typically include: a print head, an assembly (e.g., a label media cartridge) for supplying and feeding a label media past the print head in order to be printed, a microprocessor, a read-only memory (ROM) programmed with appropriate instructions therein to operate the microprocessor, a random access memory (RAM), a keyboard with letter, number, and function keys for entry of alphanumeric information requisite to printing the indicia on the label media, and a visual display such as a light emitting diode (“LED”) or liquid crystal display (“LCD”) screen to convey information to a machine operator. These components function together to achieve the end goal of creating high quality and accurate labels from the label media using the electronic label printing machine.
Labels are made from a label media. The label media itself typically is made up of a roll of pressure sensitive tape that is attached, typically along a side containing an adhesive, to a continuous support roll of release liner material. The label media is fed in a media direction along a media path through the label printer. Discrete labels are formed by cutting the label media. Complex label shapes can be obtained by plotter cutting the tape layer only of the label media. The label media can be end cut (i.e., cutting through the tape and the release liner layers) or portioned into an end cut label media portion in order to obtain as many discrete labels in a continuous row as is desired. In other words, one or more than one discrete label can reside on an end cut label media portion. An end cutting operation can occur with or without a plotter cutting operation first having taken place. Following label media cutting, the discrete labels can be removed from the release liner and attached, as appropriate, to the particular application requiring identification. Since there are many types of label applications, there are many combinations of tape and release liners that can provide labels of varying sizes, colors, formats, and characteristics.
One type of label printer employs a thermal transfer print head. In general, the use of thermal print heads in label printers has increased as the quality and accuracy of thermal print heads has improved. Thermal transfer printing uses a heat-generating print head to transfer an ink, or the like, from a thermal transfer ribbon to a label media to form a label image on the media. A microprocessor determines a sequence of individual thermal, typically resistive, print head elements to be selectively heated or energized. Energizing the sequence of elements in turn heats the ribbon so as to transfer the ink from the ribbon, creating the desired image on the label media, and specifically, on the label tape. The label printer can be fed label media from a label media cartridge. Simultaneously, a thermal transfer ribbon can be fed from a ribbon cartridge. While the label media runs between the print head and a support (platen) roller, the transfer ribbon can run between the print head and the support roller. Thus, the label media and the transfer ribbon can run together in an overlay relationship between the print head and the support roller.
When it is desired to print a color image on a label media, it is generally required to print the image by passing the label media several times past the print head. To accomplish each pass, the label media is fed, retracted, and then re-fed again past the thermal print head. With each pass, a different primary color, for example, in a traditional color scheme, cyan, magenta, yellow, and black, is printed from a continuous ink ribbon onto the label media using the print head. In this manner, based on the amount of each color printed, a composite color image can be printed onto a label media.
It is continually desirable to improve the functionality, performance and/or efficiency of various components, or combinations of components (also called “assemblies” or “subassemblies”) that make up label printers. For example, it would be desirable to improve the process of plotter cutting in label printers.
Plotter cutting effects cutting of the tape layer of the label media only. Thus, to effect proper cutting, the plotter cutter knife or blade must cut a media at a cutting depth equal to, or substantially equal to, the tape layer thickness.
A given label media, and in particular, the tape layer of a given label media, can be made from a variety of materials, for example, plastic, vinyl, a combination of plastic and vinyl, paper, PET (polyethylene terephthalate)—sometimes metallized, magnetic material, among others. Each of these materials have varying characteristic properties (e.g., stiffness, density, etc.). Moreover, label media typically vary in size (e.g., media thickness, width, etc.). In order to avoid cutting, or substantially cutting, the label media release sheet layer when plotter cutting, a system or method ideally would account for, and provide plotter cutter control despite these variations in label media. Since plotter cutting systems typically cut many varieties or types of label media, it would be advantageous for a single plotter cutter to be able to adjust to, and therefore accommodate, the various label media, as they change from one label-making run to another.
To date, however, plotter cutting operations, systems and methods have been cumbersome, requiring significant amounts of post-manufacturer user intervention, both with respect to plotter cutting set-up (e.g., manually setting an initial plotter cutter knife or blade depth) in addition to adjustment time invested throughout the plotter cutting process. Specifically, monitoring and/or controlling, in addition to setting up, of plotter cutting has been characterized as a heavily manual process based on amounts of trial and error. This has resulted in significant labor costs, increased amounts of wasted materials, particularly when the label media is varied numerous times from one label run to another.
Thus, it would be desirable to provide a system and method for controlling plotter cutting that would reduce material waste, and eliminate, or substantially eliminate, much of the trial and error that has characterized plotter cutting. Such a method and system would substantially reduce user intervention in the plotter cutting process and require little, if any, user intervention.
SUMMARY OF INVENTION
The present invention generally provides a label printer plotter cutter that overcomes the aforementioned problems. In one aspect, the present invention is directed to a method for making a media-specific plotter cut of a label media, the method comprising: providing a cutting assembly for plotter cutting the label media, the cutting assembly having frame, a force-generating mechanism connected to the frame, and a plotter cutter connected to the force-generating mechanism; supplying the label media to be plotter cut using the plotter cutter; providing a memory device for electronic communication with the cutting assembly, the memory device having a label media-specific value stored thereon, the label media-specific value corresponding to a label media-specific cutting force; reading the label media-specific value corresponding to a label media-specific cutting force from the memory device; converting the label media-specific value corresponding to a label media-specific cutting force to a label media-specific current signal; providing, based on the label media-specific current signal, a label media-specific current; applying the label media-specific current to the force-generating mechanism; generating, at the force-generating mechanism, the label media-specific cutting force based on the label media-specific current applied to the force-generating mechanism; transferring the label media-specific cutting force generated at the force-generating mechanism so that the plotter cutter will be controlled to plotter cut the label media at a label media-specific cutting depth; and plotter cutting the label media at the label media-specific cutting depth, thereby making a media-specific plotter cut on the label media.
Various other aspects, features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.
BRIEF DESCRIPTION OF DRAWINGS
Preferred embodiments of the invention are described below with reference to the following drawings, which are provided for illustrative purposes only. The drawings illustrate a best mode presently contemplated for carrying out the invention.
In the drawings:
FIG. 1 is a perspective view of a label printer that can employ a label printer cutting assembly according to one aspect of the present invention;
FIG. 2 is a perspective, cutaway view of a portion of the label printer of FIG. 1 with the interior of the printer partially exposed;
FIG. 3 is a schematic illustration of one embodiment of a printing arrangement that can be used with the printer of FIG. 1;
FIG. 4 is an angled perspective view taken along line 4 — 4 of FIG. 2 illustrating one embodiment of a label printer cutting assembly according to one aspect of the present invention;
FIG. 5 shows an enlarged cross-sectional view taken along line 5 — 5 of FIG. 4;
FIG. 6 illustrates a cross-sectional view taken along line 6 — 6 of FIG. 4;
FIG. 7 shows an enlarged cross-sectional view taken along line 7 — 7 of FIG. 6 illustrating one embodiment of the label printer cutting assembly where the plotter cutter is in a raised position off of a label media;
FIG. 8 shows an enlarged cross-sectional view taken along line 8 — 8 of FIG. 6 illustrating one embodiment of the label printer cutting assembly where the plotter cutter is in a position lowered onto the label media;
FIG. 9 is a partially schematic cross-sectional view taken along line 9 — 9 of FIG. 8 illustrating operation of the plotter cutter in accordance with one aspect of the invention; and
FIG. 10 shows a top, partially schematic view of the cutting assembly plotter cutter accomplishing a plotter cutting sequence in accordance with one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following detailed description, references are made to the accompanying drawings which form a part of this application, and in which is shown by way of illustration specific embodiments in which the invention can be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments can be utilized and that various changes can be made without departing from the spirit and scope of the present invention. Moreover, in the detailed description, like numerals are employed to designate like parts throughout the same. Various items of equipment, such as fasteners, fittings, etc., in addition to various other elements and specific principles of their operation, are omitted to simplify the description. However, those skilled in the art will realize that such conventional equipment and principles of operation can be employed as desired. Locations of various of the components, including those components shown and described herein, can be varied as desired or as the applications warrant.
Shown in FIGS. 1-2, is label printer 1 . In a preferred embodiment, printer 1 can accomplish both printing and cutting operations in a single unit, and thus, label printer 1 can also be referred to as a “label printer-cutter”. Printer 1 includes a plastic housing 2 having a front 4 , a back (not shown), a left side 6 and a right side (not shown). Printer 1 includes a cover portion 3 and a base portion 5 (FIG. 2 ). In FIG. 1, the cover portion is closed, and so printer 1 is shown in a configuration that is suitable for, for example, operation or transport. Cover portion 3 can be raised or opened to access the interior of printer 1 . Cover portion 3 can also be raised, for example, when the printer is in an idle state, or a state suitable for loading and/or unloading a label media. Cover portion 3 can be raised by releasing a temporary securing mechanism (not shown) on left side 6 of housing 2 and applying a lifting force to the cover portion. Housing 2 supports LCD screen 10 that may be pivotally mounted to housing front 4 . Printed labels (not shown) are ejected from printer 1 via exit chute 12 formed in housing side 6 . LCD screen 10 can display, among other things, printer status and error indicators to a user of printer 1 . First adjustment mechanism 13 (FIG. 1) can be included, for example, to control and/or adjust LCD screen 10 brightness. Other parameters, such as print or color intensity of an output label, can also be adjusted, for example, by second adjustment mechanism 14 .
FIG. 2 shows a cutaway view of a portion of label printer 1 . Housing 2 encloses various printer assemblies (some of which are not detailed herein to facilitate understanding of the invention), and these assemblies can be mounted to frame 8 . For example, cutting assembly 30 is attached to cutter assembly frame 31 , with frame 31 secured to frame 8 .
Label printer assemblies (e.g., cutter assembly 30 ) and LCD screen 10 are controlled by printer circuitry. Housing 2 of label printer 1 can be manufactured, along with its various assemblies, according to known manufacturing principles (e.g., injection molding) and using known materials (e.g., plastic, metal, and the like).
Although not shown, it is contemplated that printer 1 can be connected to, and usable with, a data entry device, such as a keyboard, for entering alpha-numeric information necessary for preparation and design of a desired output. Printer 1 can include firmware (e.g., software designed on a platform such as Windows CE™), available from Microsoft and software for controlling, in whole or in part, various printer assemblies, among them cutting assembly 30 . Frame 8 can be designed to hold programmable memory devices known as flash cards that can be used to store firmware and software routines. Flash cards are typically used during product development to facilitate updates to the firmware and other software. Flash cards can be replaced by permanently programmed memory chips. Using the above-described firmware and software and the associated memory devices, printer assemblies such as cutter assembly 30 can be activated and controlled in an automated fashion.
A typical thermal printing arrangement 15 is illustrated schematically in FIG. 3 since, in a preferred embodiment, the label printer of FIG. 1 can be a thermal label printer. Printing arrangement 15 includes print head 16 , support (platen) roller 17 , label media delivery roller 18 a , and label media take-up roller 18 b . Label media delivery and take-up rollers 18 a,b can be separate components, or alternatively, they can be housed within a unitary structure (e.g., a label media supply cartridge). Print head 16 is typically equipped with a linear array of thermal elements 19 . The number of thermal elements 19 in the linear array can vary, with a characteristic print head 16 employing one thousand two hundred forty-eight (1,248) thermal elements 19 . Thermal elements 19 produce heat in response to energy supplied to print head 16 . A current is applied to thermal elements 19 to heat the thermal elements 19 to a level sufficient to transfer dots onto label media 20 . This occurs when a thermally-sensitive supply 21 (e.g., an ink ribbon) comes into thermal contact with the thermal elements 19 . Printing arrangement 15 includes thermally-sensitive supply delivery roller 22 a , and thermally-sensitive take-up roller 22 b . Thermally-sensitive supply delivery and take-up rollers 22 a,b can be separate components, or alternatively, they can be housed within a unitary structure (e.g., an ink ribbon cartridge). It is contemplated that color printing can be accomplished as well as black (along with shades of gray). Directional arrows 23 indicate the direction of travel of platen roller 17 , label media delivery and take-up rollers 18 a,b and thermally-sensitive supply delivery and take-up rollers 22 a,b in printing arrangement 15 .
Referring to FIG. 4, an enlarged cross-sectional view taken along line 4 — 4 of FIG. 2 illustrating one embodiment of label printer cutting assembly 30 connected to frame 31 of printer 1 is shown according to one aspect of the present invention. Cutting assembly 30 includes a plotter cutter 32 to effectuate plotter cutting of label media 20 (shown in phantom) to form one or more discrete labels. The cutting assembly further includes end cutter 36 to effect end cutting (also called “shear cutting” or “cutting off”) of a label media. It will be recognized that end cutting can take place with or without plotter cutting of the label media having first taken place. Cutting assembly 30 is generally driven using a drive mechanism, here shown as step motor 38 . The manner in which cutting assembly 30 is driven is described in greater detail with reference to various figures below, but it is noted that belt 40 is a timing belt that is used generally to effectuate proper cutting of label media 20 via the cutting assembly. As shown, timing belt 40 is driven by step motor 38 via pulleys 39 a,b that are connected to shafts 41 a,b , respectively, with shaft 41 a connected to step motor 38 and shaft 41 b connected to bracket 43 . Bracket 43 is connected to frame 31 . Step motor 38 is also connected to frame 31 by bracket 44 . As shown, in a preferred embodiment, end cutter home sensor 42 and plotter cutter home sensor 45 are included in the cutting assembly connected to frame 31 . Sensor 42 is used to determine when end cutter 36 has reached, or is located at, a home or rest position. Similarly, sensor 45 is used to determine when plotter cutter 32 has reached, or is located at, a home or rest position. As a practical matter, the home or rest position for the end cutter (and similarly for the plotter cutter) can be reversed, or at any convenient location within frame 31 , since the firmware and/or software associated with the label printer can accommodate such positional variation.
Referring to FIG. 5, an enlarged detailed cross-sectional view of a portion of FIG. 4 is shown illustrating one embodiment of cutting assembly 30 . Cutting assembly 30 includes plotter cutter 32 and end cutter 36 . Plotter cutter 32 comprises knob 50 and a plotter cutter pin blade 52 . Knob 50 is used to adjust plotter cutter cutting depth, such as an initial cutting depth of plotter cutter cutting pin blade 52 . The initial blade cutting depth (i.e., blade protrusion) may be measured and set to a specific value at the time of label printer manufacture. Knob 50 adjusts cutting depth via connecting section or nose 51 , and the depth is adjusted with respect to label media 20 . Label media 20 rides on label support 53 , which is connected to frame 31 of label printer 1 , here via connections 57 . Label cutting pad 55 can be included below pin blade 52 between label media 20 and label support 53 . Cutting pad 55 protects pin blade 52 so as to increase pin blade cutting life. Cutting pad 55 is typically made from materials such as nylon or delrin (acetal).
Still referring to FIG. 5, plotter cutter 32 engages and slides along plotter cutter slide rail 46 and end cutter 36 engages and slides along end cutter slide rail 48 . End cutter slide 48 rail is fixedly mounted to cutter assembly frame 31 . End cutter 36 comprises clamp 64 and clamp wheel 65 to permit the end cutter to slidably engage end cutter slide rail 48 via extension 66 . End cutter 36 further comprises cutter blade 68 to accomplish cutting off or shear cutting of label media 20 . Plotter cutter slide rail 46 is pivotally mounted to cutter assembly frame 31 via pivot 54 (e.g., a pin, screw or other rotation-permitting connector). A solenoid 56 , or other force-generating mechanism (e.g., a motor and lever mechanism), is connected to plotter cutter slide rail 46 via a connection or armature 58 . Rollers 74 a,b and 76 a,b rotate and serve to position label media 20 in cutting assembly 30 for cutting. Rollers 74 a and 76 a rotate in the same direction (i.e., clockwise or counterclockwise) and rollers 74 b and 76 b will both corresponding rotate in an opposite direction to rollers 74 a and 76 a . End cutter home sensor 42 senses when end cutter extension or flag 70 activates (e.g., using an optical sensing technology) the sensor via end cutter home sensor slot 42 a . Belt 40 drives plotter cutter 32 and end cutter 36 to effect proper cutting of label media 20 in cutting assembly 30 .
FIG. 6 illustrates a cross-sectional view taken along line 6 — 6 of FIG. 4 . More specifically, FIG. 6 shows one embodiment of plotter cutter 32 in a label printer cutting assembly 30 . Cutting assembly 30 is connected to a cutter frame 31 which is secured, as noted above, to frame 8 . Plotter cutter 32 is used to effect cutting of a label media 20 to form one or more discrete labels. Again, plotter cutter 32 , as noted above, is generally carried by timing belt 40 , which is driven by step motor 38 (shown in phantom). Solenoid 56 , or other force-generating mechanism, is secured to frame 31 in a conventional manner. Solenoid 56 is also attached, via connection or armature 58 , to plotter cutter slide rail 46 . Spring 60 is shown and includes an upper end 60 a and a lower end 60 b . Spring 60 attached at lower end 60 b to cutter frame 31 via anchor 61 . Spring 60 is attached at its upper end to plotter cutter slide rail 46 .
Cutting assembly 30 is more fully described in a co-pending U.S. patent application entitled “Label Printer End and Plotter Cutting Assembly” filed concurrently herewith and which is fully incorporated herein by reference.
Referring to FIG. 7, plotter cutter 32 is shown in a rest position (i.e., a position in which plotter cutting does not take place). Compressive force of spring 60 , indicated by arrow 63 , rotates plotter cutter slide rail 46 about pivot 54 , with the rotation about the pivot indicated by arrow 67 a . Accordingly, plotter cutter 32 and its blade 52 are lifted, as indicated by arrow 62 a , off of label media 20 when plotter cutting is not taking place.
FIG. 8 generally shows the plotter cutter 32 in a plotter cutting position, that is, a position to effect plotter cutting of label media 20 into discrete labels. Solenoid 56 imparts a force to move armature 58 upwardly, indicated by arrow 67 . The solenoid force overcomes the compressive force of spring 60 (FIG. 7 ), thereby extending the spring in tension, so as to rotate or tilt plotter cutter slide rail 46 about pivot 54 , indicated by arrow 67 b . As a result, plotter cutter 32 is lowered, along with its blade 52 , downwardly, into contact with label media 20 . The downward motion of plotter cutter 32 is indicated by arrow 62 b . Plotter cutter 32 is thus placed in a plotter cutting position to cut label media 20 , with the position located generally over cutting pad 55 .
FIG. 9 shows an enlarged cross-sectional view taken along line 9 — 9 of FIG. 8 as well as a partially schematic representation of the operation of plotter cutter 32 imparting a plotter cut on label media 20 in accordance with one aspect of the present invention. Specifically, plotter cutter 32 cuts, blade 52 , label media 20 over cutting pad 55 disposed on label support 53 .
The types of label media stored in a label media cartridge can vary. As a result, the force necessary to cut a specific label media will vary with that specific media. A memory device (e.g., a memory chip, or referred to simply as “memory”) 120 can be associated with, or attached to, a label media supply cartridge 122 . In this manner, the force necessary to cut label media (i.e., label media-specific cutting force) can be stored on a memory device attached, for example, to the cartridge holding that same label media. As a practical matter, memory device 120 can store label media specific cutting force value(s) directly, or as value(s) representative of the cutting force. Memory device 120 can alternatively store values thereon from which the force can be derived. The values stored on the memory device can be current-proportional values that are representative of the media-specific cutting force. In general, it is well understood that memory devices store data. Values can be stored in a memory device in any form that can be read and processed by electronic devices to which the memory device may be connected.
A power source 124 is used to provide, via an electrical connection 128 , power to controller 126 . An electrical connection 130 can be established between memory device 120 and label printer controller 126 . By this connection, controller 126 can read or otherwise obtain from memory device 120 the values or data stored on the device that are representative of the media-specific cutting force. In one embodiment, the values are dimensionless values that can be read and processed by label printer controller 126 . The controller can convert, using computerized instructions programmed therein, the label media-specific value(s) into corresponding, media-specific current signal(s).
A media-specific current can be provided by power source 124 based on the media-specific current signal supplied by controller 126 to the power source, as illustrated, via electrical connection 132 . The media specific current can then be applied to force-generating mechanism 56 (e.g., a solenoid), via an electrical connection 134 . The current is preferably between 0 and 1 amp, and more preferably about 0.5 amp.
In general, force-generating mechanism 56 will provide a force that is proportional to the current applied to it. Therefore, at force-generating mechanism 56 , a media-specific cutting force can be generated based on the applied label specific current. In a preferred embodiment, the force-generating mechanism includes armature 58 that applies a media-specific cutting force to plotter cutter 32 . Armature 58 is responsible for imparting the media-specific cutting force to plotter cutter 32 through various intermediate physical connections, all of which are shown schematically as dashed line and arrow 136 and portion 138 . In a preferred embodiment, illustrative physical connections include, among other items, cutter pivot 54 , to transfer the media-specific cutting force, illustrated by arrow 140 , either directly or indirectly, to plotter cutter 32 via, for example, a rotational movement, indicated by arrow 139 .
Using the media-specific cutting force 140 applied from force-generating mechanism 56 , a label media-specific plotter cut can be made. “Label media-specific plotter cut” means plotter cutting of a label media at a media-specific cutting depth, denoted in FIG. 9 as “D”.
Label media 20 includes tape layer 20 a , an adhesive layer (not shown), such that the tape is releasably attached to release or substrate layer 20 b . Again, plotter cutting, as here used and shown, results in cutting label media tape layer 20 a (along with the adhesive layer). Release or substrate layer 20 b is not cut or substantially cut via plotter cutting of plotter cutter 32 . Accordingly, media-specific plotter cutting depth “D” can generally correspond to the thickness of tape layer 20 a.
Some label media materials will require a lesser cutting force than others to achieve cutting depth “D”. A lesser cutting force necessarily will require less current, and therefore, less energy. Accordingly, an energy savings can be realized using the present invention. Perhaps even more significantly, because the force transferred by the force-generating mechanism will correspond to a specific cutting depth, a plotter cutter blade need not be manually adjusted for each specific label media that is desired to be cut.
Label material (e.g., plastic, vinyl, etc.) and dimension (e.g., height, width, thickness) can vary from one label-making run to another. Since each media cartridge housing a given label material can be provided with an operably-associated memory device, each media cartridge can be said to be equipped with its own label media depth “pre-programmed” into the memory device associated with the cartridge. In this fashion, plotter cutter cutting depth can be controlled in a fashion that results in repeatable, accurate, and label media-specific plotter cuts.
FIG. 10 shows a top, partially schematic view of plotter cutter 32 accomplishing a plotter cutting sequence along a cutting path 170 in accordance with one aspect of the present invention. Cutting path 170 is representative of a plotter cut that has already taken place. Cartesian coordinates 150 are included for clarification purposes. Plotter cutter 32 is driven, as noted previously, by a drive mechanism, such as step motor 38 , via shaft 41 a connected via pulley 39 a to belt 40 . Plotter cutter 32 , as shown, can move in both positive and negative x directions, as indicated by arrows 154 a and 154 b , respectively. Label media 20 is driven by a drive mechanism, such as step motor 156 . Motor 156 drives label media 20 in a positive or negative y direction, indicated by arrows 158 a and 158 b , via driving rollers 74 b and 76 b (shown in phantom). Specifically, rollers 74 b and 76 b are connected to step motor 156 via shafts 160 and 162 . Belt 164 and pulleys 166 , 168 permit step motor 156 to drive both rollers 74 b and 76 b . Rollers 74 a and 76 a , as shown, are pinch or passive rollers.
Plotter cutter 32 is shown having traversed, from a right edge 26 to a left edge 28 , of label media 20 in a negative x direction to create cutting path 170 . During the cutting operation that has taken place to institute a plotter cut along path 170 , label media 20 has been moved in both positive and negative y directions.
More specifically, cutting path 170 includes cutting path portions 170 a-f , where each of the portions corresponds to plotter cutter 32 and/or label media 20 movement as follows: portion 170 a corresponds to negative x cutting by plotter cutter 32 while label media 20 remains stationary; portion 170 b corresponds to positive y movement of label media 20 while plotter cutter 32 cuts, but remains stationary; portion 170 c corresponds to negative x cutting by plotter cutter 32 while label media 20 remains stationary; portion 170 d corresponds to negative y movement of the label media 20 while plotter cutter 32 cuts, but remains stationary; portion 170 e corresponds to negative x cutting by plotter cutter 32 , as well as negative y movement of label media 20 ; and portion 170 f corresponds to negative x cutting by plotter cutter 32 while label media 20 remains stationary.
While a particular preferred embodiment has been shown and described above, it is apparent that the teachings of this invention may be applied utilizing other hardware performing the same or equivalent functions. It is contemplated that cartridges for holding and/or supplying one or both of the ribbon and/or label media supplies can be of the “re-usable” (also called “refillable”) type, but preferably are of the “disposable” type.
Methods have been described and outlined in a sequential fashion. Still, elimination, modification, rearrangement, combination, reordering, or the like, of the methods is contemplated and considered within the scope of the appending claims.
In general, while the present invention has been described in terms of preferred embodiments, it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims. | Methods and systems are disclosed for controlling cutting depth of a label media such that the depth of cut is media-specific, that is, specific to the media being cut. The method includes: providing a plotter cutter and a force-generating mechanism; providing a memory device for electronic communication with the plotter cutter, the memory device having a label media-specific value stored thereon; reading the label media-specific value from the memory device; converting the label media-specific value to a label media-specific current signal; providing a label media-specific current based on the label media-specific current signal; applying the label media-specific current to a force-generating mechanism; generating a label media-specific cutting force based on the label media-specific current; and transferring the label media-specific cutting force to the plotter cutter to control plotter cutting at the label media-specific cutting depth. The methods and systems work towards eliminating waste or scrap plotter test cuts by plotter cutting a label media using information from, for example, a memory device associated with a label media supply. The methods and systems obviate the need for manual resetting of plotter cutter depth from one label media to another. | 1 |
TECHNICAL FIELD
This invention relates to hydrocarbon recovery, and in particular to the formation of gels useful in formation fracturing.
BACKGROUND OF THE INVENTION
In the recovery of hydrocarbons from underground formations, it is common to fracture the formations with fluids forced down a wellbore under considerable pressure. Various types of fracturing fluids may be used. This invention is concerned with the use of hydrocarbon fracturing fluids, such as kerosene, Diesel oil, and the like. It is common to viscosify or gel hydrocarbon fracturing fluids so they are better able to handle and distribute the propping agents commonly mixed with them. Propping agents such as sand or other relatively hard particulates are used to maintain the fissures in the formation after they are fractured, to assure the recoverable hydrocarbons in the formation are able to flow through the formation to be recovered.
It is desirable that the additives for the fracturing fluid should act rapidly and efficiently to make a useful--that is, a viscous--gel from a small amount of chemical.
Dialkyl orthophosphates, particularly in the form of their aluminum salts, have been used as components of hydrocarbon gelling agents for many years--see the generic description in Monroe's U.S. Pat. No. 3,575,859, for example, issued in 1971. Monroe uses the dialkyl phosphate esters in combination with alkyl and alkanol amines having up to 4 carbon atoms; he also uses certain polyamines. In U.S. Pat. No. 4,153,649, Griffin lists eighteen U.S. patents said to teach the preparation of phosphate esters useful in formation fracturing, incorporates them by reference, and goes on to discuss several others. More recently, McCabe, in U.S. Pat. No. 5,271,464, employs alkyl orthophosphate esters with aluminum and iron compounds to make a gel; he uses them in combination with a monohydric alcohol having from 2 to 4 carbon atoms and an alkyl or alkanol amine having from 8 to 18 carbon atoms. The gel is used as a temporary plugging agent. McCabe also, in European Patent Application 0 551 021 A1, suggests a similar composition as a fracturing agent.
Smith and Persinski (U.S. Pat. No. 5,417,287) suggest iron compounds in combination with orthophosphate esters to make a viscous hydrocarbon fracturing medium, and, in U.S. Pat. No. 5,614,010, include a low molecular weight amine and, optionally, a surfactant.
SUMMARY OF THE INVENTION
Our invention comprises compositions and methods for gelling hydrocarbon fracturing fluids. The composition comprises a phosphate ester preferably neutralized with potassium hydroxide, dibutylaminoethanol, iron sulfate, and a phosphate surfactant, in the proportions described herein.
The method includes adding the composition to a hydrocarbon fracturing fluid to create a viscous fracturing fluid. The invention further includes a method of fracturing subterranean formation using the gelled hydrocarbon, with or without a proppant, under pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a computer printout showing gel stability of our invention at 200° F. under two different revolutions per second of the Fann Viscometer.
FIG. 2 is similar to FIG. 1 but shows gel stability of a lower concentration of our activator.
FIG. 3 plots the close time for gels activated by our activator, using increasing amounts of KOH in the gelling agent.
FIG. 4 shows the crown time for our gels using increasing amounts of KOH.
FIG. 5 shows the Marsh Funnel time for the gels of FIGS. 3 and 4.
DETAILED DESCRIPTION OF THE INVENTION
Our preferred method of viscosifying a hydrocarbon fracturing fluid is to employ two separate compositions--a phosphate ester which is neutralized by potassium hydroxide, and an activator.
The basic components of our new activator are, in parts by weight:
30-48 parts by weight iron sulfate
5-25 parts by weight dibutyl amino ethanol, and
5-20 parts by weight phosphate surfactant as described below. Dibutyl amino ethanol is sometimes described herein as DBAE.
A preferred activator comprises, by weight, (a) about 50% to about 80% of a 60% solution of iron sulfate, (b) about 5% to about 10% of a solvent selected from isopropanol, ethylene glycol, and butyl cellosolve, (c) about 5% to about 25% dibutyl amino ethanol and (d) about 5% to about 20% of a phosphate surfactant.
The phosphate surfactants we prefer are ethoxylated phosphate esters, and their alkali metal salts, of mono- and disubstituted phenols; the substitutions on the phenolic moieties are hydrocarbon chains of eight to twelve carbon atoms. The amount or ethoxylation may vary considerably, i.e. from one ethoxy unit to ten, fifteen, or more. Some examples, (including their commercial trademarks of Rhone-Poulenc) are:
1. "RM 510"--Polyoxyethylene dinonyl phenyl ether phosphate CAS Registry Name: poly(oxy 1-2 ethanediyl), alpha (dinonylphenyl) omega hydroxy phosphate
2. "RM 410"--Polyoxyethylene dinonlyphenyl ether phosphate CAS Registry Name: poly(oxy 1-2 ethanediyl), alpha-(dinonylphenyl)-omega hydroxy phosphate
3. "RE 410"--polyoxyethylene nonylphenyl ether phosphate CAS Registry Name: poly(oxy 1-2 ethanediyl) alpha-(nonylphenyl)-omega hydroxy, branched, phosphate
4. "RA 600"--complex alkyl phosphate ester CAS Registry Name: poly(oxy 1-2 ethanediyl) alpha omega hydro mono C 8-10
5. "RE 610"--polyoxyethylene nonlyphenyl, branched phosphate CAS Registry Name: poly(oxy 1-2 ethanediyl) alpha (nonylphenyl) omega hydroxy, branched phosphate.
These phosphate surfactants and similar phosphate surfactants are sometimes referred to herein as "phosphate surfactants".
The efficacy of our composition was demonstrated in a series of experiments. The experiments included close, crown and Marsh funnel tests for several series of ranges and proportions of the components of our system.
The procedure was as follows. In each case, 300 ml of clear, dye-free, additive-free Diesel oil was added to a Waring blender. The blender speed was set at 1500-1800 rpm using a digital tachometer before the Diesel was added to the blender cup. The Diesel oil was added, the blender started, the gellant (80% active phosphate ester with KOH if noted) was added; then the activator (see the definition above) and the stop watch started. Closure is the time for the ball on the bottom of the blender to disappear; crowning is the time after closure for the vortex to disappear. After two minutes of mixing, the sample was transferred to the Marsh funnel and given a 30 seconds rest. Then the sample was permitted to flow through the Marsh funnel and the time the gel takes to reach the 100 ml line on a 300 ml beaker is recorded as Marsh funnel time. A 52 ml sample was then transferred to the Fann viscometer as soon as possible. The Fann viscometer program ran at 40 revolutions per second and 100 revolutions per second with a b5 bob.
For each of the tests, a 60% solution of iron sulfate was used. Several amines with similar molecular weights were mixed with the iron sulfate solution, which was then placed in hydrocarbon fracturing fluid containing 0.5% orthophosphate ester, unless stated otherwise, (and with varying amounts of KOH as noted) and the rapidity of gellation was measured in terms of the results of close, crown and Marsh funnel tests. The phosphoric acid ester used as the gelling agent in each case was the reaction product of phosphoric acid with C 8-10 alcohols. These and related gelling agents based on phosphoric acid esters are described by Smith and Persinski in U.S. Pat. Nos. 5,417,287, 5,571,315, 5,614,010, and 5,647,900; we may use any of the gelling agents described in these patents, which are incorporated herein by reference.. HGA 715 is 80% phosphate ester, 15% of a 45% active solution of KOH, and 5% solvent.
A series of close, crown, and Marsh funnel tests was run to determine the optimum concentration of DBAE. The results of these tests are shown below in Table I, from which it may be seen that 20% DBAE, based on the ovarall activator composition, was the optimum concentration. A range of 15% to 25% is quite efficient and is a preferred range in our invention. All gels were made at 0.5% gellant and 0.5% activator.
TABLE I______________________________________5% DBEA 10% DBEA 15% DBEA 20% DBEA 25% DBEA 60% Fe.sub.2 SO.sub.4 60% Fe.sub.2 SO.sub.4 60% Fe.sub.2 SO.sub.4 60% Fe.sub.2 SO.sub.4 55% Fe.sub.2 SO.sub.4 10% 10% 10% 10% 10% RM510 RM510 RM510 RM510 RM510 10% Ipa 10% Ipa 10% Ipa 10% Ipa 10% Ipa 5% water 10% water 5% water Close:0:19 Close:0.07 Close:0.03 Close 0:03 Close:0:06 Crown:no Crown:0:20 Crown:0:07 Crown:0:06 Crown:0:10 Marsh:0:10 Marsh:0:25 Marsh:1:21 Marsh:2:16 Marsh:8:48 MF1hr:0:43 MF1hr:0:54 MF1hr:0:59______________________________________
Then, a series of screenings were run to select a surfactant to further enhance the rapidity of gelation Isopropanol is used in combination with the surfactant, in a ratio of 3:2 to 2:3, preferably 1:1.
TABLE II______________________________________Surfactant Close Time Crown Time Marsh Funnel______________________________________PL 620 1.49 None 0:07 R5 095 None None 0:02 RA 600 0:04 0:06 1:05 RB 610 0:07 0:12 2:28 RE 510 0:04 0:06 0:06 RE 410 0:04 0:06 0:58 RM 510 0:04 0:06 1:54______________________________________
The temperature stability of our gels is shown in FIGS. 1 and 2. FIG. 1 shows the results in the Fann Viscometer or 0.5% phosphate ester (neutralized with 15% KOH solution as stated above) and 0.5% activator. The upper edge of the band represents the result at 40 rpm and the lower edge of the band represents the result at 100 rpm. In FIG. 2, 0.3% gelling agent and 0.3% activator were used; again, the higher values are at 40 rpm and the lower ones are at 100 rpm.
An activator formulation comprising 60% iron sulfate (60% conc.), 20% DBAE, and 10% phosphate surfactant (RM 510) was now tested against phosphate ester compositions having twenty different incremental amounts of KOH neutralizer. These results are shown graphically in FIGS. 3, 4, and 5. An optimum neutralization of the phosphate ester is in the range of about 8-18% KOH, taking all three criteria--close time, crown time, and Marsh funnel time--into account, although any amount from 0-20% will have beneficial effects. | Method and composition for gel formation in hydrocarbon recovery, in which an organic phosphate ester is gelled by a novel activator composition comprising iron sulfate, dibutylaminoethanol, and a phosphate surfactant. | 8 |
BACKGROUND OF THE INVENTION
[0001] Media certification testing is performed for all disk drive media and is used to screen the media for defects in the magnetic layers. These defects include scratches, voids from missing media material and other media defects. Testing is generally done on special testers that include a spindle for holding and spinning the disks, head positioners (or actuators) for precisely locating the test head on the disk surface, and computers, controllers and software controlling the tester and interpreting the test results.
[0002] Generally, media certification testing is done by writing a track of bit signals with a write head or element and then reading back signal with a read head or element. If there are any defects on the disk the read back signal (output) will be compromised. In industry practice, the testing is done with one of two prior art methods.
[0003] The first prior art test procedure is referred to as Spiral Testing. It is performed with two separate or discrete heads as shown in FIG. 1 . Specifically, this form of Spiral Testing uses a separate write and a separate read head that are attached to a head gimbal assembly (HGA). The HGA is then connected to separate head positioners (or actuators). These head positioners are generally very accurate positioning devices with servo and/or encoded positioning feedback. However since there is a build up of tolerances associated with using two heads and positioners there is difficulty in maintaining write track to read track alignment. Misregistration of write to read is generally considered being off-track. The alignment or centering of the disk to the spindle also contributes to this off-track problem since if not perfectly centered, the track will be written in an elliptical pattern. The industry practice to eliminate the off-track alignment problems is for the write head to be very wide, for example, 25 microns to 75 microns or more.
[0004] Spiral Testing has three primary limitations. First, the wide write test track is not feasible with perpendicular recording technology. The wide write width will not enable proper magnetization of the perpendicular media due to write saturation effects. There are also limitations with the wide write heads for longitudinal recording. Generally these limitations are due to the ability of longitudinal write head technology to properly achieve write saturation on the high coercivety media. If proper write saturation is not achieved the read back signal will be week and the ability to detect defects will be compromised. There are also limitations with the supply and availability of this older write head technology which makes them more scarce and costly. Secondly, Spiral Testing also has difficulties with testers maintaining write to read on track accuracies. If the read head is not properly aligned with the prewritten write track, the readback signal (output) will be compromised and the tester may consider this inaccuracy as a disk defect. Commonly, wide write tracks are used to overcome this difficulty. Thirdly, the tester requires two separate heads and head positioners for performing this test. The two heads are both expensive and lead to misregistration due to the requirement of aligning two separate heads.
[0005] The second prior art test procedure is referred to as Step and Repeat Testing as shown in FIG. 2 . Step and Repeat Testing employs a single head with integrated write and read elements. In Step and Repeat Testing each track 201 is tested by being written and read before moving the head to another track to test. The Step and Repeat Testing method has the advantage of eliminating the tolerance problem with two separate heads and head positioners and elliptical write track patterns. Furthermore, this testing method allows the write element structure to have a narrower write track to better enable proper write saturation. Lastly, there does not need to be two separate heads and scanners. This is because the same head writes and reads the test data and includes both a read and a write element.
[0006] However, the Step and Repeat Testing method has a disadvantage versus Spiral Testing in testing time and throughput. Step and Repeat Testing requires time to write one track and then read that same track during the next revolution. After reading, the head positioner needs to move the head to another track, which requires additional time to move and settle. Then this write-read-move cycle is repeated. Thus, Step and Repeat Testing is between two to three times longer than Spiral Testing. This additional time has a big impact to media manufactures due to the additional testers and space required to overcome the slowness of the method.
[0007] What is needed is an effective testing procedure that is both fast and efficient.
SUMMARY OF THE INVENTION
[0008] Described is a procedure, Integrated Head Spiral Testing. Integrated Head Spiral Testing utilizes a single head with both a write and a read element that are offset. This head structure and the procedure allows for the benefits of both Spiral Testing and Step and Repeat Testing without many of the drawbacks. The procedure utilizes a single integrated head that includes a write element offset from a read element. The read and write elements can be offset by a predetermined amount that is also matched to the head positioner movement per revolution. One example of such a matching is the head positioner moving the head 15 microns for every disk revolution which would be equal to the offset of the write and read elements. The procedure includes the write element continuously writing while the scanner moves at a constant travel rate of 15 microns per revolution. The net result will be a write track written in a spiral. After one or more revolutions the read head will continuously read the prewritten track and will follow the write head in the same spiral pattern. This spiral track is written and read in a manner similar to a record needle following a grove in a record.
[0009] The method eliminates the tolerance problems of using two separate heads and scanners. Further, the write element can be made small enough to overcome the write saturation problems. In addition, Integrated Head Spiral Testing drastically improves throughput over the Step and Repeat method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a figure describing (prior art) Spiral Testing.
[0011] FIG. 2 is a figure describing (prior art) Step and Repeat Testing.
[0012] FIG. 3 a is a figure of a head to be used with prior art methods.
[0013] FIG. 3 b is a figure of a head to be used with Integrated Head Spiral Testing.
[0014] FIG. 4 a is a figure demonstrating Integrated Head Spiral Testing.
[0015] FIG. 4 b is a second figure demonstrating Integrated Head Spiral Testing.
[0016] FIG. 4 c is a third figure demonstrating Integrated Head Spiral Testing with a portion of the spiral track between the portion of the spiral track being written and the portion of the spiral track being read.
[0017] FIG. 5 is a flow chart for Integrated Head Spiral Testing.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The following description is of the best embodiments presently contemplated for carrying out this invention. This description is made for the purpose of illustrating the general principles of this invention and is not meant to limit the inventive concepts claimed herein.
[0019] FIG. 3 a shows a head 301 consistent with the prior art. The head includes a write element 302 and a read element 303 . The write element 302 writes a write track 304 . The read element 303 reads a read track 305 . As can be seen from FIG. 3 a , read track 305 is encompassed by write track 304 due to the positioning and size of read element 303 and write element 302 . Further, both write element 302 and read element 303 generally have the same track center line.
[0020] FIG. 3 b shows an Integrated Head Spiral Testing head 306 including a write element 307 which is offset from a read element 308 to be used with Integrated Head Spiral Testing. The write and read elements read offset write track 309 and read track 310 respectively. The offset between the write track 309 and the read track 310 is the write to read offset 311 . The write to read offset may determine the spiral scan/positioner scan rate of the Integrated Head Spiral Testing method described below. The offset is generally a predetermined amount, such as 15 microns. The offset can be by the same distance as determined by the spiral scan rate (microns per revolution) divided by an integer. The write and read element offset can be arranged using common head fabrication process using photolithography masks to offset the alignments between the write and read element structures.
[0021] The integrated head 306 is mounted on a head gimbal assembly to suspend and electrically connect the head to tester mounting surfaces and electronics. An Integrated Head Spiral Testing method, as shown in FIG. 5 , to test a disk media is described below. The test can be implemented with head 306 . The Integrated Head Spiral Testing head 306 is loaded on the tester head positioner 501 . A disk is loaded on the tester spindle and the tester spindle spins up to testing velocity 502 . The head 306 is then loaded over a disk surface and positioned over the starting point of the disk 503 . A write function is enabled and the head positioner moves laterally at a constant rate 504 . The write function is enabled to write test data on a continuous spiral track, for example, from the OD of the disk to the ID of the disk. This spiral track pitch is created by the continuous lateral movement of the head positioner (for example 15 microns lateral movement per disk revolution). This head positioning movement in relationship to the disk rotation velocity will be controlled by the tester controller and software. The spiral write track is written so that the head is capable of writing a part of the track at the same time it reads earlier portion of the track.
[0022] A read function is then enabled and reads back a prior written portion of the spiral track after at least one revolution 505 . Writing and reading to and from the disk by the head 306 continues simultaneously until the testing of the disk is complete 506 . Tester software then determines if the readback signal has shown a suspected defect 507 by looking to see if the data written to the disk matched the corresponding data read from the disk or if the readback signal is diminished. If a suspected defect has been identified, the testing cycle can be interrupted and the defect site can be retested to validate that a defect has been found 508 . Otherwise the disk passes the test. Once the testing is complete, tests may be performed on additional disks 509 .
[0023] FIG. 4 a demonstrates pictorially a portion of a method described herein. The head 306 with write element 307 and read element 308 is positioned so that it can write the portion of the spiral track 312 while simultaneously reading an earlier written portion of the spiral track 313 . Portion of spiral track 312 is offset from portion of spiral track 313 by the write read offset 311 . Further, the method can be implemented to have any number of portions of the spiral track between portions of the spiral track 312 and 313 so long as the write and read elements 307 and 308 are positioned over the portions 312 and 313 . FIG. 4 b is a full disk view of the method described herein. FIG. 4 c is a second full disk view of the method described herein. This figure has a portion of the spiral track 314 between the currently written portion of the spiral track 312 and the currently read portion of the spiral track 313 . The lateral movement of the head positioner in the case of FIG. 4 c would be one half the read write offset per disk revolution.
[0024] Testers that have already been equipped with two positioners as stated in the first prior art descriptions can be retrofitted with two Integrated Head Spiral Testing heads on each positioner. Each head can be assigned to different radii on the disk to test. This essentially doubles the throughput of a Spiral Testing tester. In addition each of the Integrated Head Spiral Testing can write an interleaved and non-intersecting spiral on the disk.
[0025] While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Other embodiments falling within the scope of the invention may also become apparent to those skilled in the art. Thus, the breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | Testing procedure (Integrated Head Spiral Testing) for disk media utilizes a single head with both write and read elements that are offset to allow spiral testing. The offset allows a write element to write one portion of a spiral track while a read element simultaneously reads a previously written portion of the spiral track. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 09/613,294, filed Jul. 10, 2000 now U.S. Pat. No. 6,945,572, which claims the benefit of U.S. Provisional Application Ser. No. 60/214,493, filed Jun. 27, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sliding door latch assemblies, and more particularly to the combination of a sliding door and latch assembly in which the latch, although behind or under the door pull handle, is conveniently operated by having the lever that operates the latch mounted beyond the area of the handle, and coupled to the latch by an elongated mechanism that translates the rotary action of the lever to rotary shifting of the latch from beyond the handle area.
2. Description of the Related Art
Sliding doors have leading stiles that fit to the doorjamb. The door lock comprises a latch that interfits with a keeper in the doorjamb. Sliding doors are heavy and may not slide easily after a time. Typical handles provide for but a finger hold to move the door. Accordingly, better, larger handles are required, but there is little space on the latch assembly for the handle unless the area over the latch actuation mechanism is used. This handle placement, however, leads to difficulties in operating the mechanism in its hidden and difficult to reach location.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to enable the use in sliding doors of larger handles that can be gripped by more than the fingertips while avoiding the difficulties that such placement of the handle causes when the handle in order to be adequate in size and shape tends to block the hand movement needed to reach the latch and latch lever. It is a further object to eliminate the resultant interference with latch operation and door locking and unlocking that use of larger handles has precipitated.
It is another object of the invention to provide a sliding door and latch assembly that provides a large handle for door shifting but is readily latched as well. It is a further object to provide an improved latch assembly that is accessible despite the presence of the larger handle. It is a still further object to provide a sliding door latch assembly that vertically spaces the latch and the latch lever such that the lever is accessible beyond the handle while the latch is within the housing locus where the handle is located. It is a further and specific object to provide an elongated, vertically disposed 4-bar coupling of the spaced latch and lever that translates the rotation of the lever into rotation of the latch for shifting the latch into or out of latching relation with the latch keeper.
These and other objects of the invention to become apparent hereinafter are realized in a sliding door latch assembly comprising a vertically extended housing having a vertically disposed pull handle opposite a housing locus extending over a major portion of but not all of the vertical extent of the housing, a latch mounted within the housing locus and shiftable to and from the housing for locking the sliding door to a cooperating keeper mounted in a sliding doorjamb opposite the latch, a rotary actuator within the housing locus for shifting the latch, a hand-operated lever rotatably mounted to the housing beyond the housing locus, the lever being vertically spaced a predetermined distance from the rotary actuator, the lever being rigidly linked to the rotary actuator for rotatably actuating the latch by the rotatable lever without having the lever within the housing locus, whereby hand actuation of the lever and latch is free of interference from the pull handle.
In this and like embodiments, typically, the latch is hook-shaped and the cooperating keeper comprises a slot; the housing is rectangular in cross-section; the lever further includes a rotatable lever plate, the lever plate and the lever being mounted to a common pivot for rotation together responsive to hand operation of the lever; the rotary actuator comprises a rotatable latch plate, the latch plate and the latch being mounted to a common pivot for rotation together responsive to actuation of the latch plate by the lever; the lever further comprises a rotatable lever plate, the lever plate and the lever being mounted to a common pivot for rotation together responsive to actuation of the latch plate by the lever, the lever plate and the latch plate being rigidly coupled such that rotation of the lever plate causes a like rotation in the latch plate and the latch, there is also included a pair of bars movably fixed to and extending between the lever plate and the latch plate, the bars being arranged to transmit rotary movement of the lever plate to the latch plate, and the bars are of a length to extend from within the housing locus to beyond the housing locus and across the predetermined vertical distance.
In a further embodiment, the latch is hook-shaped and the cooperating keeper comprises a slot, the housing is rectangular in cross-section and comprises front, rear and side walls, the front wall being slotted to pass the latch in shifting relation to and from the keeper, the side walls supporting the latch assembly, the pull handle is an inside handle sized for grasping with several fingers, and including also an outside handle fixed to the housing, and there is also included a sliding door having a leading stile, the leading stile defining the housing.
In a further embodiment, the invention provides a sliding door and latch assembly having a vertically disposed pull handle, a rotatable latch lever beyond the handle and a rotatable latch opposite the handle, and a 4-bar coupling between the lever and the latch, whereby the latch is rotatable from beyond the pull handle for engaging a cooperating keeper.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will be further described in conjunction with the attached drawings in which:
FIG. 1 is an exploded view of the invention sliding door latch assembly, partly broken away to show underlying parts;
FIG. 2A is a top plan view of the latch assembly;
FIG. 2B is a side elevation view thereof; and
FIG. 2C is a bottom plan view thereof.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to the drawings in detail, in FIGS. 1 and 2 the invention sliding door latch assembly, generally indicated at 10 , comprises a vertically extended housing 12 that is suitably a portion of the leading stile 14 of the sliding door 16 . Secured to one side of the housing 12 is an escutcheon plate 12 a and a vertically disposed pull handle 18 opposite a housing locus 22 extending over a major portion of but not all of the vertical extent of the housing. The handle 18 is connected to the escutcheon plate 12 a at one or more connection points 18 a . Extending from the front face of the escutcheon plate 12 a is a lever 46 , for actuation by a user. An actuator shaft 45 extends from the opposite face of the escutcheon plate 12 a to mate with slot 47 on the latch housing 25 . The latch 24 proper extends from latch housing 25 that is mounted within the housing locus 22 , the latch being shiftable to and from the housing for locking the sliding door to a cooperating keeper 26 mounted in a sliding door jamb opposite the latch.
The latch 24 is suitably hook-shaped; its cooperating keeper 26 comprises a slot 27 sized to receive and retain the latch hook portion. Housing 12 is suitably rectangular in transverse cross-section and comprises front wall 28 , rear wall 32 , and side walls 34 , 36 . Housing front wall 28 is slotted to pass the latch 24 in shifting relation to and from the keeper 26 . Side walls 34 , 36 support the latch housing 25 in position through mounting screws 38 . Pull handle 18 defines the door inside handle and is sized for encirclement by and grasping with several fingers. An outside handle 42 is also fixed to the housing 12 to complete the door and latch assembly.
It will be noted that the handle 18 covers much of the housing locus 22 , and will cover a latch-operating lever that is in the typical position. The invention places the latch 24 in the typical position in housing locus 22 , but moves the latch operating lever to a position that is not behind or covered over by the handle 18 . For this purpose the invention uses a 4-bar linkage 25 that transmits the rotary motion of the lever to the latch actuator as follows: A rotary actuator 44 located within the housing locus 22 serves to shift the latch 24 in locking and unlocking relation by rotation of shaft 45 in latch housing slot 47 . A hand-operated lever 46 is rotatably mounted to the housing 12 beyond the housing locus 22 . Lever 46 is vertically spaced a predetermined distance D from the rotary actuator 44 and rigidly linked to the rotary actuator for rotatably actuating the latch 24 by the rotatable lever without having the lever within the housing locus 22 . Thus, hand actuation of the lever 46 and shifting of the latch 24 is free of interference from the pull handle 18 .
Lever 46 includes a rotatable lever plate 48 , the lever plate and the lever being mounted to a common pivot, shaft 52 , for rotation together responsive to hand operation of the lever. The rotary actuator 44 comprises a rotatable latch plate 54 , the latch plate and the latch being mounted to a common pivot, shaft 45 , for rotation together responsive to actuation of the latch plate by the lever 46 and its rotatable lever plate 48 . Lever plate 48 defines a first bar 49 , and lever plate 54 defines a second bar 55 . Bars 58 , 62 define third and fourth bars of the 4-bar linkage 25 . Bars 58 , 62 are movably fixed to bars 49 , 55 at either edge of the lever and latch plates 48 , 54 , respectively, and extending therebetween, so as to transmit rotary movement of the lever plate to the latch plate. It will be noted the bars 58 , 62 are of a length to extend from within the housing locus 22 to beyond the housing locus and across the predetermined vertical distance D.
The invention thus provides a sliding door and latch assembly that provides a large handle for door shifting but is readily latched as well, and an improved latch assembly that is accessible despite the presence of the larger handle that vertically spaces the latch and the latch lever such that the lever is accessible beyond the handle while the latch is within the housing locus where the handle is located. In particular, the invention provides an elongated, vertically disposed 4-bar coupling of the spaced latch and lever that translates the rotation of the lever into rotation of the latch for shifting the latch into or out of latching relation with the latch keeper. The foregoing objects are thus met. | A sliding door has a latch assembly and a vertically disposed pull handle that would normally interfere with convenient operation of the latch lever. A rotatable latch lever is located beyond the handle and a rotatable latch is located opposite the handle. A 4-bar coupling extends between the lever and the latch so that the latch is conveniently rotatable from beyond the pull handle for engaging a cooperating keeper. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Present Disclosure
This disclosure relates generally to protective sleeves and more particularly to a sleeve for protecting the end of a fence post.
2. Description of Related Art including information disclosed under 37 CFR 1.97 and 1.98.
Fisher, U.S. Pat. No. 94,195, discloses a design for a post support, such design showing a box-like construction with a chiseled lower edge and an open top for receiving a square post. Side fins extend from two opposing sides of the support.
Banks, U.S. Pat. No. 1,402,561, discloses a post support providing a cylindrical receiver, chisel lower edge, disk shaped cap portion, and outwardly and downwardly extending stabilizing teeth.
Knowles, U.S. Pat. No. 5,082,231, discloses a post support for permanent installation at or below ground level including a post receiving collar affixed to fins. The fins have collar supporting shoulders against which a post may rest. A driver/cap/marker has a cap and sleeve with sleeve length the same as the collars length so that when the driver/cap/marker is inserted into the collar the lower edge of the sleeve rests on the shoulders and the underside of the cap/marker rests on top of the collar. The driver/cap/marker serves firstly as a tool for inserting the support into he ground and secondly as a cover for an unused support, and thirdly for marking the location of an unused collar.
Wells, U.S. Pat. No. 5,165,663 discloses a ground anchor for a post including an elongated vertically extending cylindrical PVC tube and including at the lower end of the tube an end member having a cylindrical portion snugly and frictionally fit within the tube and a conical portion projecting downwardly from the tube to a point, the end member having thereon within the tube an upwardly facing drive surface. An elongate driving member is removable insertable into the tube and has at one end a driving which is engagable with the free surface on the end member. In a variation, the tube has at the upper end a collar which includes an axially extending annular flange snugly fir within the upper end of the tube and a further annular flange projecting radially outwardly from the support end of the axial flange.
Boyd et al., U.S. Pat. No. 5,535,555, discloses a breakaway post coupling with a hollow, tubular sleeve which accommodates a ground-mounted stub post and a top, sign-supporting post. The sleeve is held onto the posts by a plurality of pins which engage a corresponding plurality of slots in the sleeve. Collars slidably engage the sleeve and force the pins into the post material as the collars are drawn over the sleeve and pins. A plurality of cutouts in the sleeve define a shear point in the coupling. When the top post is struck by a vehicle, the coupling breaks at the shear point, leaving an intact stub post upon which a new top post can be joined.
Fitzsimmons et al., U.S. Pat. No. 5,571,229, discloses a support structure or ground sleeve for supporting a pole including a cap threadably engagable with an open end of a sleeve body. The ground sleeve includes a sleeve body adapted to be positioned in a ground surface for receiving and supporting a pole and includes at least one flange extending outwardly from the sleeve body for preventing the sleeve from rotating in the ground, a collet for engaging the pole, and an inwardly tapered closed end of the sleeve body for centering an end of the pole. An inwardly tapered race surface of the cap and a plurality of circumferentially-spaced tabs of the sleeve body cooperate to define the collet. In addition, the ground sleeve is formed of a weather resistant non-corrosive material.
Killick, U.S. Pat. No. 5,625,988, discloses a support assembly for a roadside or traffic signpost includes a mounting socket cylinder fixed in the ground for receiving a support post therein. A resilient support means in the form of a pair of O-rings is interposable between the post and the mounting cylinder. A reinforcing collar prevents deformation of adjacent portions of the mounting cylinder and the post.
Aberle, U.S. Pat. No. 5,632,464, discloses a ground pocket support device for removably mounting a post having variable cross-section shape and size. The ground pocket support device includes an elongate ground engaging member having upper and lower end portions. The member is adapted for placement in the ground and defines a hollow post-receiving portion for receiving and supporting a post in a substantially upright position. The ground engaging member further includes elongate wall members and a post wedging mechanism positioned toward the lower end portion for firmly engaging the lower end of a post inserted therewithin. A post-engaging member is disposed at the upper end portion of the ground engaging member. The post-engaging member includes members for removably anchoring a post inserted within the ground engaging member and for adjusting the vertical alignment of the post independent of the vertical alignment between the ground engaging member and the ground in which it is placed.
Peery, Jr., U.S. Pat. No. 5,704,580, discloses a method and apparatus for assembling a selected street pole to a standard sized base. The method includes the step of selecting a street pole of a predetermined configuration. Encircling portions, preferably rings consisting of two semi-circular portions, each having a nestable section with each other and a complementary section with the selected street pole are then provided. The encircling portions are nested together on the standard sized base to connect the standard sized base to the selected street pole thereby continuing the appearance finish of the standard sized base while preventing unauthorized access to an interior of the standard sized base. The apparatus includes the encircling portions to connect the standard sized base to the selected street pole.
Zuares, U.S. Pat. No. 5,832,675, discloses a prefabricated flashing for post bases intended for installation in new or existing construction comprising two different pieces. One piece having a nailing flange which fits snugly around a post whose dimension is five-sixteenths of an inch square, and has a total of eight nail holes and four tapered sides that terminate in a bottom flange. The second piece is shaped and sized similarly to the first except that it is split vertically straight across the nailing flange and on one side has an extension of material which creates a seam.
Doeringer et al., U.S. Pat. No. 5,901,525, discloses an elevated column base for supporting a wood column subjected to high mechanical loads and protecting the column lowermost portion from rot and other deterioration due to exposure to a tropical environment. The column base includes a stanchion, a diaphragm, and a cap, each monolithically molded from a thermoplastic. A first embodiment of the stanchion adapted for a 6.times.6 or 8.times.8 column includes a solid base portion with a cavity which is filled with concrete and plugged with the diaphragm. The stanchion has two pairs of side walls attached to the base portion. Opposed gussets attached to the upper portions of one pair stiffen the side walls against transverse loads. Most of the load carried by the wood column is borne by the concrete and by two horizontal bolts. The diaphragm acts to spread the load force to the base portion and side walls. The load on the diaphragm acts to create a seal against moisture entering the cavity. A second embodiment of the stanchion adapted for a 4.times.4 column does not include gussets. The cap has four lateral faces fitting closely over the stanchion side walls, and a top face with a square aperture formed by four flexible web portions pressing against the wood column. After the column lowermost portion is secured within the stanchion by the bolts, the cap is slid downwardly until the ends of slots in the lateral faces contact the bolts. Each cap bottom corner edge and trough then bound an aperture through which water collected above the diaphragm can drain.
The prior art teaches various means for mounting and protecting a buried end of a post or beam. However, the prior art does not teach a peripheral elastomeric seal that has means for accepting one end of a protective sleeve and that is able to compressed by a molding against a post to attain a water and insect proof enclosure. The present invention fulfills these needs and provides further related advantages as described in the following summary and detailed description and as shown in the accompanying corresponding figures.
BRIEF SUMMARY OF THE INVENTION
This disclosure teaches certain benefits in construction and use which give rise to the objectives described below.
Wooden posts are widely used for outdoor fences and similar applications. Such posts are subject to the elements and insect attack so that they typically need to be replaced periodically. Additionally, such posts are mounted by burying one end into the earth or mounting one end to a concrete footing with metal brackets. These approaches are not aesthetically pleasing and tend to leave the lower end of the post vulnerable to water damage and insect infestation. The above defined prior art devices provide improvements in this field, but clearly, further improvements and post mounting solutions are needed and the present invention is one approach that provides such benefit that is clearly novel and which provides practical benefits over the prior art.
In a preferred embodiment of the present invention, the post has a rectangular cross-sectional shape, typically four inches square, and is mounted within a protective sleeve. The sleeve provides a cylindrical sidewall and a bottom cap closing the end of the sidewall and sealing the end of the post. An elastomeric seal is engaged with the sidewall peripheral to the post, and a pair of L-shaped moldings are mounted exterior to the seal providing engagement within a groove of the elastomeric seal and exerting a sealing force against the elastomeric seal and the post to achieve a waterproof assembly that also is aesthetically pleasing.
A primary objective inherent in the above described apparatus and method of use is to provide advantages not taught by the prior art.
Another objective is to seal the lower end of a post so as to prevent insect attack and water damage.
A further objective is to provide an improved seal between the posts' mounting and the post itself so as to exclude water from the lower end of the post.
A still further objective is to provide a post mounting that is easily installed and later removed as necessary.
A still further objective is to provide a seal that provides mechanical and weather resistant engagement between a sleeve and the post.
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 presently described apparatus and method of its use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
Illustrated in the accompanying drawing(s) is at least one of the best mode embodiments of the present invention In such drawing(s):
FIGS. 1 , 2 and 3 are perspective views of an elastomeric seal of the presently described apparatus as seen from one side, above and below respectively;
FIGS. 4 and 5 are perspective views of a cylindrical sidewall closed at one end by a cap of the apparatus as seen from above and from below respectively;
FIG. 6 is a perspective view of the sidewall and cap engaged with an elastomeric seal as seen from above;
FIGS. 7 and 8 are perspective views of the elastomeric seal engaged with a pair of L-shaped moldings as seen from below and from above respectively;
FIG. 9 is a perspective view of the sidewall and cap of FIG. 4 with the elastomeric seal and moldings of FIG. 8 mounted on the sidewall; and
FIG. 10 is a cross sectional view showing the constructional details of the engagement of the elastomeric seal with the molding, sidewall and the post as taken along line 10 - 10 in FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
The above described drawing figures illustrate the described apparatus and its method of use in at least one of its preferred, best mode embodiment, which is further defined in detail in the following description. Those having ordinary skill in the art may be able to make alterations and modifications to what is described herein without departing from its spirit and scope. Therefore, it must be understood that what is illustrated is set forth only for the purposes of example and that it should not be taken as a limitation in the scope of the present apparatus and method of use.
Described now in detail is the present invention, a protective sleeve which is mounted on and engages one end of a post, as shown in FIGS. 1-10 . An elongate post 10 ( FIG. 10 ), has a rectangular cross-sectional shape and opposing terminal ends. Such a post 10 is widely used and very well known in the art. A protective sleeve 20 is an assembly made up of several components including: a cylindrical sidewall 22 ( FIG. 4 ); a bottom cap 24 ( FIG. 5 ), a pair of identical L-shaped moldings 26 ( FIGS. 8 and 10 ); and a rectangular peripheral elastomeric seal 28 ( FIGS. 1-3 ). Additionally, fastening hardware 30 is used to interconnect the moldings 26 at opposing corners.
The cap 24 is engaged with a bottom end 23 of the cylindrical sidewall 22 by a bonding adhesive or other well known attachment means that is able to provide a sealed joint, weather and insect proof. A top edge 25 of the sidewall 22 is positioned within a downwardly directed first groove G 1 of the elastomeric seal 28 so that moisture and insects are not able to pass through this joint. To further assure that this joint is impermeable, a bonding adhesive may be inserted into groove G 1 . This joint is best shown in FIG. 10 .
Moldings 26 are positioned around the elastomeric seal 28 , as shown in FIGS. 7 and 8 , with terminal ends 27 of the moldings 26 mutually joined in such manner as to secure the moldings 26 to the elastomeric seal 28 , thereby securing the elastomeric seal 28 to the sidewall 22 , and forcing the elastomeric seal 28 against the post 10 thereby securing the protective sleeve 20 to the post 10 for preventing moisture to enter between the elastomeric seal 28 and the post 10 . The elastomeric seal 28 provides an outwardly directed second groove G 2 which receives an interior ridge or ridges 29 present on each of the moldings 26 , i.e., on all four sides thereof. Please see FIG. 10 for details.
Preferably, the elastomeric seal 28 provides a slopped surface 40 terminating upwardly at a peripheral ridge 42 . Likewise, the moldings preferably provide an interior slopped surface 44 in contact with the slopped surface 40 of the elastomeric sea 28 . These surfaces 40 and 44 lead water that tends to move between the molding 26 and the elastomeric seal 48 away from post 10 , and as shown in FIG. 10 , such moisture cannot enter the space between sidewall 22 and the post 10 .
Preferably, fasteners 30 are directed across the terminal ends 27 of the moldings 26 so as to provide for cinching the moldings tightly around the molding 26 as shown in FIG. 9 . Preferably, the fasteners 30 comprise a female threaded receiver pressed into hole 45 in one of the moldings 26 , and a common machine screw inserted into a clearance hole 46 in the adjoining one of the moldings 26 . In their positions, angled across the ends 27 , the fasteners 30 are positioned within the second groove G 2 of the elastomeric seal.
It should be noted, that the moldings 26 may alternately comprise four linear sections instead of two L-shaped portions or one U-shaped portion and one linear portion. Also, the apparatus may take an alternate shape other than square or rectangular as is shown in the illustrations. For instance the apparatus may be round or oval for accepting a post of that shape.
The enablements described in detail above are considered novel over the prior art of record and are considered critical to the operation of at least one aspect of the apparatus and its method of use and to the achievement of the above described objectives. The words used in this specification to describe the instant 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 must be understood as being generic to all possible meanings supported by the specification and by the word or words describing the element.
The definitions of the words or drawing elements described herein are meant 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 described and its various embodiments or that a single element may be substituted for two or more elements in a claim.
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 equivalents within the scope intended and its various embodiments. 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. This disclosure is thus meant to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, what can be obviously substituted, and also what incorporates the essential ideas.
The scope of this description is to be interpreted only in conjunction with the appended claims and it is made clear, here, that each named inventor believes that the claimed subject matter is what is intended to be patented. | A post has a rectangular cross-sectional shape and mounted on one end of the post is a protective sleeve. The sleeve provides a cylindrical sidewall within which one end of the post is engaged. A bottom cap closes the end of the sidewall sealing the end of the post. A rectangular elastomeric seal is engaged with the sidewall peripheral to the post. A pair of L-shaped moldings are mounted exterior to the elastomeric seal providing engagement within a groove of the elastomeric seal and exerting a sealing force against the elastomeric seal and the post. | 4 |
This is a continuation of application Ser. No. 855,677 filed Nov. 29, 1977, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to a method of treating lignocellulosic or cellulosic pulp produced by chemical, semi-chemical, and chemimechanical types of pulping processes. More particularly it relates to the treatment of a lignocellulosic or cellulosic pulp with gaseous ammonia, which treatment promotes the kinking of pulp fibres and/or improves the tearing strength of paper prepared therefrom.
2. Description of the Prior Art
The kraft pulping process is a widely used chemical pulping process. Paper manufactured from kraft pulp is of good quality and is particularly characterised by high strength. However the kraft process is inherently highly polluting and the pulp is produced in a low yield, for example of about 45%. For purposes of this specification, the term "pulp yield" means the percentage of original dry wood material that is converted to dry pulp.
There are alternative high yield processes some of which are used commercially. Among these is the bisulphite process with which pulps have been produced at a yield in excess of 60%. There are in addition other high yield chemical or semi-chemical processes which have not yet achieved commercial acceptance. In addition less polluting processes, such as the two stage soda-oxygen pulping process have attracted considerable commercial interest.
As will be apparent from the above, alternatives to the kraft process can be attractive either because they are more acceptable environmentally or because they produce a greater yield of pulp. A disadvantage common to many of these alternative processes is that paper produced from the pulp resulting from these processes is a paper of low tearing strength. The other properties of papers produced from alternative pulps are in many cases either superior to or comparable with those of corresponding papers produced from kraft pulp. We have found that when a pulp prepared by a chemical or semi-chemical or chemimechanical process other than the kraft process is treated by the ammonia process according to the invention described and defined hereinbelow, there is an improvement in the tearing strength of the pulp so treated.
The gaseous ammonia treatment according to this invention also improves the tearing strengths of pulps produced by the kraft process and in this regard is particularly applicable to kraft pulps made from young, low density wood. Tearing strength is an important property in most end uses, particularly the manufacture of paper bags and sacks.
The treatment according to this invention has also been observed to induce and to set kinks in the pulp fibres. It is to be understood that what is meant by kinking of pulp fibres includes changes in the fibre configuration, such as, for example, in the extent of fibre twist, curl and kink as well as fibre wall dislocations, fractures, microcompressions and zones of dislocation. The presence of kinked fibres within a papermaking pulp is known to bring about an improvement in the properties of wet webs and in some of the papers produced from such webs. Kinked fibres are known to be particularly effective in developing extensibility in wet webs if the kinks are set in position so that they remain somewhat inflexible when the webs are subjected to strain during papermaking and dry lap production. Kinked fibres are also known to improve the extensibility of some papers produced from them.
Gaseous ammonia and aqueous ammonia solutions have been used as the alkaline reagent in oxidative delignification of lignocellulosic material and is described, for example, in British Pat. No. 1,381,728 and U.S. Pat. Nos. 3,617,432; 3,740,311; and, 4,002,526. Ammonia has also been used in conjunction with other gaseous reagents such as chlorine or chlorine dioxide to effect bleaching of wood pulp as is described, for example, in New Zealand Pat. No. 160,216, and U.S. Pat. No. 3,472,731.
In none of this prior art is there disclosed the use of ammonia in a separate treatment step in order to achieve the desired changes in the properties of the wood pulp being treated. The effects which gaseous ammonia has on wood pulp or other cellulosic fibres is unpredictable from any of the literature of which we are aware.
It is an object of this invention to go some way towards achieving the desiderata described above or at least providing the public with a useful choice.
SUMMARY OF THE INVENTION
Accordingly the invention may be said broadly to consist in a method of treatment of a lignocellulosic or cellulosic pulp derived from a chemical, semi-chemical or chemimechanical pulping process, which method comprises saturating said pulp with an effective amount of gaseous ammonia.
Preferably said effective amount is sufficient gaseous ammonia to be taken up by moist pulp in an amount greater than 3% by weight of oven dry pulp.
Preferably said treatment is effected by subjecting the said pulp to a substantially gaseous ammonia atmosphere under a pressure of at least 1 atmosphere (101.3 kPa).
Preferably said method comprises a cycle consisting essentially of a first step of subjecting said pulp to substantially gaseous ammonia atmosphere followed by subjecting said pulp to a vacuum.
Alternatively said process is carried out in two or more cycles, each cycle comprising a said subjection to an atmosphere of ammonia followed by subjection to vacuum.
One embodiment comprises treating pulp at a yield of up to 80%. Another embodiment comprises treating pulp having a consistency of up to 40 weight percent of dried pulp in the total material, water plus pulp.
Alternately the process comprises up to five pressure phases of up to 2 hours each alternating with pressure release phases of up to 1 hour between each phase.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention may be more fully understood by having reference to the following examples and tables, setting out the preferred embodiments of the invention. It is to be noted that these examples are exemplary and do not delimit the scope of the invention.
EXAMPLE 1
Sodium bisulphite pulps made from radiata pine slabwood chips in yields of 53, 60,67 and 75 percent were refined (beaten) to varying degrees (2000-8000 revolutions) in a laboratory PFI (Papirindustriens Forskninginstitutt) mill. Samples of the pulps were pressed to a consistency of 15-30 percent and then fluffed. Control (untreated) samples were washed with distilled water and standard paper handsheets made and tested. Additional pulp samples were placed in a stainless steel pressure vessel which was then evacuated for 10 minutes. These pulps were then treated with gaseous ammonia for 1-3 cycles of 15-45 minutes each at total pressures of 380-760 kPa. The vessel was evacuated for 10 minutes between treatment cycles and at the end of each treatment. Treated pulps were washed thoroughly with distilled water and standard paper handsheets made and tested.
Specific gaseous ammonia treatment conditions and the corresponding paper properties are given in Table 1. The gaseous ammonia treatment caused handsheet tearing strengths (tear index) to be increased significantly by up to 92 percent. The burst (burst index) and tensile (tensile index) strengths were decreased by proportionately small extents of up to 36 percent. Handhsheet stretch was not affected greatly by the treatment (this was confirmed in other experiments). Thus, pulps refined in order to develop paper stretch and burst and tensile strengths can then be treated with gaseous ammonia to selectively develop tearing strength.
EXAMPLE 2
Samples of the 60 percent yield bisulphite pulp referred to in Example 1 were refined for 5000 revolutions in a PFI mill, pressed to 22.5 percent consistency and fluffed.
TABLE 1 EFFECTS OF GASEOUS AMMONIA TREATMENT ON PAPER PROPERTIES TREATMENT CONDITIONS HANDSHEET PROPERTIES PFI Stock Number of Time per Ammonia A pparent Burst Tensile Scattering Pulp yield Beating Concn Treatment cycle Pressure Freeness density Tear index index index Stretch Coeff. Brightness Example No. Pulp type (%) (revs) (%) Cycles (min) (kPa) (Csf) (kg/m.sup.3) (mN.m.sup.2 /g) (kPa.m.sup.2 /g) (N.m/g) (%) (cm.sup.2 /g) (%) 1. Bisulphite slabwood 53 2000 15 -- Untreated -- 782 600 14.7 5.6 70 2.7 176 43.1 " " " 3 45 380 746 577 23.6 4.3 54 2.8 195 37.3 53 8000 30 -- Untreated -- 422 644 12.6 6.6 74 3.0 157 42.2 " " " 1 45 760 669 592 22.1 4.3 51 2.7 198 35.8 60 5000 22.5 -- Untreated -- 668 583 13.4 6.1 76 2.7 171 40.2 " " " 2 30 570 734 554 21.4 4.1 54 2.8 190 30.4 67 2000 15 -- Untreated -- 766 492 16.8 4.3 61 2.3 196 39.1 " " " 1 45 380 751 493 22.1 3.7 51 2.2 196 30.4 67 8000 30 -- Untreated -- 680 553 11.7 5.6 70 2.8 176 37.2 " " " 3 15 380 728 535 22.5 3.6 48 2.5 189 29.3 75 8000 30 -- Untreated -- 737 498 14.1 4.7 59 2.2 190 47.3 " " " 1 60 760 753 502 17.7 3.8 45 2.1 190 36.7 2. Bisulphite slabwood 60 5000 22.5 -- Untreated -- 650 583 12.5 6.2 73 2.8 167 39.6 low application of " " " 1 45 <120 658 582 13.1 5.9 72 2.8 165 35.9 gaseous ammonia (in admixture with nitrogen) 3. Soda-oxygen slabwood 50 5000 15 -- Untreated -- 642 621 15.5 7.0 77 3.3 167 26.6 (29 Kappa No.) " " " 1 45 760 698 588 29.4 4.7 56 3.4 197 27.4 Bleached after treatment " " " " " " 687 591 35.7 4.1 46 3.5 225 87.1 Bleached before treatment " " " " " " 712 587 31.4 3.6 49 3.4 235 84.6 4. Kraft slabwood 48 2000 22.5 -- Untreated -- 736 565 25.5 4.2 56 2.6 189 23.2 (30 Kappa No.) " " " 2 30 570 741 534 29.0 2.5 37 2.2 215 23.5 48 8000 22.5 -- Untreated -- 658 613 21.4 6.2 72 3.1 163 22.1 " " " 2 30 570 724 562 31.7 3.2 46 3.1 192 22.2 5. Kraft corewood 48 2000 22.5 -- Untreated -- 659 709 17.0 5.8 54 5.6 202 23.4 (32 Kappa No.) " " " 2 30 570 687 684 19.7 5.1 49 6.4 232 24.5 48 8000 22.5 -- Untreated -- 555 751 15.2 6.6 71 6.2 151 21.0 " " " 2 30 570 660 712 18.3 4.9 59 6.6 211 23.3 An untreated sample was evaluated and a further sample treated in the manner described in example 1 except that a mixture of gaseous ammonia and nitrogen was bubbled through the pulp at a pressure lower than 120 kPa (less than 2 psig). This was done to determine the lower limits of ammonia application. The uptake was estimated from the rapid temperature increase (using the heat of solution of ammonia in water) to be approximately 8.6 percent by weight on oven dry pulp. Following treatment the pulp was evaluated.
Paper properties given in Table 1 showed that such a low uptake of ammonia had a very small effect on the handsheet properties. The most significant difference was an undesirable decrease in brightness.
EXAMPLE 3
Four samples of a two-stage soda-oxygen pulp made from radiata pine slabwood chips in a yield of 50 percent and with a Kappa number of 29 were refined for 5000 revolutions in a PFI mill and pressed to 15 percent consistency. The pulps were washed, fluffed and an untreated sample was evaluated (i.e. standard paper handsheets made and tested). Two samples were treated with gaseous ammonia in a manner similar to that described in example 1. (See Table 1 for specific treatment conditions). One of these pulps was washed and evaluated while the other was bleached to high brightness by a standed CEDED (chlorination, alkali extraction, chlorine dioxide bleach, alkali extraction, chlorine dioxide bleach) bleaching sequence prior to evaluation.
The fourth pulp was bleached in the same manner (CEDED sequence) and then treated with gaseous ammonia prior to evaluation.
Tearing strengths were greatly improved in all three ammonia treated soda-oxygen pulps (Table 1) by from 90 to 130 percent. Corresponding burst and tensile strengths were decreased, but to acceptable levels (i.e. 49 N.m 2 /g tensile index). Again handsheet stretch was retained following treatment with gaseous ammonia.
Tearing strengths of the two bleached pulps were even greater than those of the unbleached, treated pulp. Pulp treatment with ammonia before bleaching was slightly more effective than treatment after bleaching in developing both handsheet strength and brightness (Table 1).
EXAMPLE 4
Kraft pulp samples made from radiata pine slabwood chips in a yield of 48 percent and with a Kappa No. of 30 were refined in a PFI mill for 2000 and 8000 revolutions. Both untreated and gaseous ammonia treated (Table 1) pulps were evaluated.
Paper properties (Table 1) showed that the treatment improved tearing strengths but decreased burst and tensile strengths almost proportionately. As kraft slabwood pulps are generally already of high tearing strength, the treatment may not prove of great value for this purpose. However, as shown in Example 7, the treatment was beneficial for kraft slabwood pulps in that it promoted fibre kinking which improves wet web extensibility.
EXAMPLE 5
Kraft pulp samples made from radiata pine corewood (young wood) chips in a yield of 48 percent with a Kappa No. of 32 were refined as in Example 4. Untreated and gaseous ammonia treated pulps (Table 1) were evaluated.
Paper properties (Table 1) showed that gaseous ammonia treatment could be beneficial on corewood kraft pulps which generally are of low tearing strength and high burst and tensile strengths. Tear index was increased by about 3 units (20 percent) and the corresponding burst and tensile strengths were acceptable.
EXAMPLE 6
A sample (containing the equivalent of about 100 grams of oven-dry pulp) of the 53 percent yield bisulphite pulp (Example 1) was refined for 8000 revolutions, pressed to 15 percent consistency and fluffed. The moisture content of the pulp was determined by oven-drying three small samples and the remaining pulp was weighed and then treated with gaseous ammonia under extreme treatment conditions (3 cycles of 45 minutes each at a pressure of 760 kPa). The pulp was then washed, oven-dried, and weighed to determine the yield loss caused by the treatment.
The yield was found to decrease from 53 to 51.9 percent which is an extremely small yield loss, especially when possible losses due to handling are considered. Previous experiments indicated that the yield loss for bisulphite pulps was very small at all pulp yields considered (Example 1).
BRIEF DESCRIPTION OF THE FIGURES
The invention as it is described herein below in Example 7, may be more fully understood by having reference to the accompanying figures wherein:
FIG. 1A is a photograph of a magnification of a pulp produced at a 53% yield at 8000 refining revolutions in a PFI mill without treatment according to the present process.
FIG. 1B is a photograph of a magnification of the same pulp treated with gaseous ammonia at a stock concentration of 30% over two cycles of 45 minutes per cycle under a pressure of 760 kPa.
FIG. 2B is a photograph of a magnification of a pulp produced at a 67% yield at 8000 refining revolutions in a PFI mill without treatment according to the present process.
FIG. 2A is a photograph of the magnification of the same pulp treated with gaseous ammonia at a stock concentration of 30% over 3 cycles of 45 minutes per cycle under a pressure of 760 kPa.
FIG. 3A is a photograph of a magnification of a wet web with a solids content of 22.7% prepared from a pulp of 53% yield at 8000 refining revolutions in a PFI mill, the wet web having been treated by the ammonia process of the present invention, before straining.
FIG. 3B illustrates the same web after straining to rupture.
FIG. 4A is a photograph of a magnification of a wet web prepared from a pulp which has not been treated by the ammonia process of the present invention, the web having a solids content of 24.5% and having been produced at a pulp yield of 53% at 8000 refining revolutions on a PFI mill, the web being unstrained.
FIG. 4B is a photograph of a magnification of the same wet web strained to rupture.
EXAMPLE 7
Pulp treatment with gaseous ammonia caused fibres to become kinked to different extents depending on wood type, pulp type, pulp yield, pulp refining, and the conditions of treatment with ammonia (Table 2). Extents of fibre kink brought about by treatment with ammonia were greatest for the more heavily beaten low yield bisulphite pulps, and lowest for the less beaten high yield bisulphite pulps (FIG. 1,2). "Kink index" is a measure of both the number and degree of fibre kink. Kibblewhite, Tappi 57(8): 120-1 (1974).
Treatment with gaseous ammonia was effective in causing the fibres in a wide range of chemical and semi-chemical pulps to become kinked. These included sodium bisulphite, kraft, soda-oxygen, and neutra-sulphite-semi-chemical pulps produced from radiata pine wood chips. Pulps from selected slabwood and corewood (young or juvenile wood) chip samples were examined and found to be kinked to varying extents by pulp treatment with gaseous ammonia (Table 2).
Fibre kinking was strongly correlated with handsheet density. Extents of fibre kinking increased linearly with decreasing handsheet densities (Table 1). Similar, although less highly correlated trends were obtained for the extents of fibre kink and handsheet burst and tensile indices. Tearing strengths on the other hand were not necessarily linearly correlated with extents of fibre kinking. This conclusion was, however, based on a limited number of samples (Table 2) and tear/kinking correlations may well be obscured by the variation inherent in measuring tearing strength.
Kinked fibres developed by treatment with gaseous ammonia were found to resist straightening when in strained wet webs (FIG. 3). Extents of resistance to fibre straightening during wet web straining were dependent on fibre type, pulp yields, degrees of pulp refining before treatment, wet web solid contents, and the extents of fibre kink developed by ammonia treatment. Fibre kinks were apparently both developed and set into position (to different degrees) by pulp treatment with gaseous ammonia.
Wet webs prepared from treated pulps containing strongly kinked fibres were observed to remain essentially unchanged when these webs were strained to the point of rupture (FIG. 3). Fibrillar networks connecting adjacent fibres were found to remain essentially intact in the strained webs. Thus, the kinked fibres were not moved relative to one another to large extents as the wet web was strained to the point of rupture. The kinked fibres were, however, straightened and fibrillar networks were disrupted when they were located within the rupture zone, as expected. Examination of wet webs prepared from corresponding untreated pulps showed low extents of fibre kink before straining, and increased degrees of fibre straightening and fibre orientation as these wet webs were strained to rupture (FIG. 4).
Pulp treatment with gaseous ammonia in general caused wet web tensile and stretch properties to be respectively decreased and increased (Table 2). Effects of the ammonia treatment on wet web strength properties generally compared with those of corresponding dry handsheets although increases in wet web extensibilities brought about by the pulp treatment were often proportionately greater than those in the dry papers. The small increases in wet web extensibility and the relatively large decreases in wet web tensile strengths were related to the decreased apparent densities (increased bulks) of the wet webs which were brought about by pulp treatment with gaseous ammonia (Table 2).
The wet web strength data are included as an indication of the effects of treatment with gaseous ammonia, and are only applicable for webs without fibre orientation at solid contents of 20-25 percent. Wet web strips were formed using a British standard sheet machine and tested on an Instron tester using jaws described by Stephens and Pearson (Appita 23(4): 261-74 (1970)).
TABLE 2__________________________________________________________________________EFFECTS OF GASEOUS AMMONIA TREATMENT ON THE DEVELOPMENTOF FIBRE KINKING Pulp AMMONIA TREATMENT CONDITIONS Beating Time Kinks Kink Pulp before Stock Per (No. per Index Yield trmt concn No. of Cycle Pressure mm of (per mmNo. Pulp Type (%) (rev) (%) Cycles (min) (kPa) fibre) fibre)*__________________________________________________________________________1 Bisulphite 53 8000 -- Untreated -- 1.5 1.9 slabwood 30 1 15 380 1.8 2.3 15 1 15 760 2.1 2.7 15 3 45 760 3.7 6.0 30 3 45 760 4.6 8.32 Bisulphite 67 8000 -- Untreated -- 1.8 2.2 slabwood 15 1 45 760 2.7 3.5 30 1 45 380 2.7 3.7 30 3 15 380 3.1 4.1 30 3 45 760 3.9 5.9 30 1 45 7603 Kraft 48 7000 -- Untreated -- 1.6 1.9 slabwood (Kappa 15 1 45 760 2.4 3.4 No. 30)4 Kraft 48 9000 -- Untreated -- 2.8 4.0 corewood (Kappa 15 1 45 760 4.8 8.2 No. 32)5 Soda- 50 5000 -- Untreated -- 1.5 1.7 oxygen (Kappa 15 1 45 760 2.6 3.6 slabwood No. 29) HANDSHEET PROPERTIES WET WEB PROPERTIES Web Tear Tensile Apparent Tensile solids index index Stretch density index Stretch content No. (mN.m.sup.2 /g) (N.m/g) (%) (kg/m.sup.3) (N.m/g) (%) (%)__________________________________________________________________________ 1 12.6 73 3.0 644 1.31 15.6 24.5 20.4 51 2.7 633 1.12 14.2 22.0 18.5 61 3.0 629 1.11 15.8 21.1 23.4 43 2.9 573 0.75 18.5 21.8 21.5 37 2.9 561 0.65 17.6 22.7 2 11.7 69 2.8 553 0.74 7.4 22.2 17.0 56 2.7 530 19.2 50 2.6 534 22.4 48 2.5 535 16.7 41 2.6 516 0.61 9.1 24.1 3 18.8 77 3.1 622 1.14 10.4 24.1 31.3 57 3.2 585 0.76 11.9 20.9 4 16.2 73 6.2 754 1.11 16.1 22.6 18.6 56 6.6 718 0.73 16.8 19.2 5 15.5 77 3.3 621 1.05 11.7 21.5 29.4 56 3.4 588 0.77 13.4 21.0__________________________________________________________________________ | The invention relates to a process comprising the saturation of a lignocellulosic or cellulosic pulp in gaseous ammonia. In one embodiment this is followed by subjection of the saturated pulp to vacuum. The treatment promotes the kinking of pulp fibres and/or improves the tearing strength of paper prepared therefrom. | 3 |
BACKGROUND OF THE INVENTION
The invention relates to an extracorporeal blood chamber, to an extracorporeal blood line and to an apparatus for treatment of extracorporeal blood.
In particular the extracorporeal blood chamber is for air/liquid separation and/or for the mixing of two liquids, for example blood and an infusion liquid.
Specifically, though not exclusively, the invention can be usefully applied in a hemo(dia)filtration system for mixing extracorporeal blood with a replacement fluid.
U.S. Pat. No. 5,605,540 describes an extracorporeal blood chamber provided with an expansion chamber having on a bottom thereof a first and a second access and at the top thereof at least a third access; the blood chamber is further provided with a first and a second conduit, terminating respectively in the first and second accesses, and with a third conduit terminating in the first conduit. In use the first and the second conduit transport blood, while the third conduit transports an infusion liquid.
U.S. Pat. No. 4,681,606 describes an extracorporeal blood chamber provided with an expansion chamber having at a bottom thereof a first access, on a side thereof a second access, and at a top thereof two further accesses; the blood chamber also has a first and a second conduit terminating respectively in the first and the second access. In use the first and the second conduit transport blood, while one of the top accesses is connected to an injection tube.
U.S. Pat. No. 5,591,251 describes an extracorporeal blood chamber provided with an expansion chamber having at a bottom thereof a first access, on a side thereof a second access, and at a top thereof another two accesses; the blood chamber further has a conduit terminating in the first lateral access. In use the first and the second access are for the passage of blood, while one of the top accesses is for passage of an infusion liquid.
U.S. Pat. No. 4,666,598 describes an extracorporeal blood chamber provided with an expansion chamber having on a bottom thereof a first access and on a side thereof a second access; the blood chamber also has a first conduit terminating in the first access, a second conduit terminating in the second access, and a third conduit terminating in the first conduit. In use the first and the second conduits transport blood, while the third conduit transports an infusion liquid.
The prior-art extracorporeal blood chambers can be improved upon in relation to the effectiveness of the mixing between the blood and the infusion liquid, especially in the case of a hemo(dia)filtration treatment with mixing between the blood and the replacement liquid upstream of the hemo(dia)filter (pre-dilution). In a case of pre-dilution the effectiveness of the hemo(dia)filtration treatment depends on the degree of mixing between the blood and the replacement liquid at the inlet of the hemo(dia)filter.
SUMMARY OF THE INVENTION
An aim of the present invention is to provide an extracorporeal blood chamber with which very good mixing results of the blood with an infusion liquid can be obtained.
A further aim of the invention is to realise an extracorporeal blood line comprising the above-mentioned blood chamber.
A further aim of the invention is to provide an apparatus for extracorporeal blood treatment comprising the above-cited blood line.
An advantage of the invention is that it provides an extracorporeal blood chamber which is able efficiently to separate the air from the liquid, in particular the air contained in the infusion liquid.
A further advantage is that it makes available an extracorporeal blood chamber which reduces to a minimum the turbulence in the blood flow in the case of absence of infusion liquid flow, i.e. when the blood is not mixed with the liquid.
A still further advantage is that the extracorporeal blood chamber is compact and small.
The aims and more besides are all attained by the invention, as it is characterised in one or more of the appended claims.
Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of at least an embodiment of the invention, illustrated by way of non-limiting example in the figures of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The description will be made herein below with reference to the appended figures of the drawings, provided by way of non-limiting example, in which:
FIG. 1 is a diagram of the hemo(dia)filtration apparatus of the invention;
FIG. 2 is a front view of an apparatus made according to the diagram of FIG. 1 , and applied operatively to the front panel of a machine for dialysis;
FIG. 3 is a perspective view from behind of the apparatus of FIG. 2 , with some parts removed better to evidence others;
FIG. 4 is a perspective view from the front of FIG. 3 ;
FIG. 5 is a perspective view from behind of the infusion module of the apparatus of FIG. 3 , with some parts removed and other parts added with respect to FIG. 3 ;
FIG. 6 is a view from the front of FIG. 5 ;
FIG. 7 is a front view of a component of the infusion module of FIG. 3 which includes the blood chamber 12 in which the mixing between the blood and the infused liquid takes place;
FIG. 8 is a view from behind of FIG. 7 ;
FIG. 9 is a view from above of FIG. 7 ;
FIG. 10 is a view from below of FIG. 7 ;
FIG. 11 is a view from the left of FIG. 7 ;
FIGS. 12 , 13 , 14 and 15 are sections according respectively to lines XII, XIII, XIV and XV of FIGS. 7 , 8 and 11 .
DETAILED DESCRIPTION
With reference to FIG. 1 , 1 denotes in its entirety an extracorporeal blood treatment apparatus destined for coupling to a machine is for extracorporeal blood treatment able to provide a treatment fluid. In the following description the extracorporeal blood treatment apparatus will be called a hemo(dia)filtration apparatus 1 , the extracorporeal blood treatment machine will be called a dialysis machine and the treatment fluid will be called dialysis fluid, without any more generalised references being lost by use of this terminology. In particular the dialysis machine produces on-line a dialysis fluid of predetermined chemical composition (for example by mixing water and solid and/or liquid concentrates). The dialysis machine is able to reduce the concentration of endotoxins in the dialysis fluid (for example by passage of dialysis fluid through one or more stages of ultrafiltration). The dialysis machine is able to provide a control system of patient weight loss during the treatment (for example by a control of the difference between the dialysis fluid delivery at the inlet and outlet of the blood treatment device thanks to the use of two pumps arranged before and after the blood treatment device—hereinafter hemo(dia)filter—and of two flow-meters arranged before and after the hemo(dia)filter). The hemo(dia)filtration apparatus 1 can be composed, all or in part, by disposable elements. The dialysis machine (of which the front panel is partially illustrated in FIG. 2 ) is of known type, is provided with a fresh dialyser fluid port 2 (see the diagram of FIG. 1 ), from which the dialysis fluid to be introduced in the hemo(dia) filter is taken, an exhausted fluid port 3 , in which the fluid exiting the hemo(dia)filter is discharged (made up of used dialysis fluid and/or of ultrafiltrate), and an on-line port 4 from which the dialysis fluid, to be processed for use as replacement fluid in hemo(dia)filtration treatment, is taken. The dialysis machine is further provided with a system of known type and not illustrated, for preparation of the dialysis fluid; this system is connected to a main dialysis fluid supply line, which terminates in the fresh dialysate port 2 . A secondary dialysis fluid supply line, which branches from the main supply line, terminates in the on-line port 4 . The dialysis machine is further provided with an exhausted liquid discharge line which originates at one end at the exhausted liquid port 3 and which terminates at the other end thereof in a drainage (of known type and not illustrated). When the hemo(dia)filtration apparatus 1 is used as a hemofiltration apparatus 1 , the fresh dialysate port 2 is closed, or non-operative, or, in a further embodiment, absent.
The hemo(dia)filtration apparatus 1 comprises the hemo(dia)filter 5 having a blood chamber and a fluid chamber (not illustrated) which are separated from one another by a semipermeable membrane (not illustrated) which, in this case, comprises a bundle of hollow fibres. In this embodiment the blood chamber comprises the space internally of the hollow fibres, while the fluid chamber comprises the space externally of the hollow fibres. The fluid chamber is further at least partially defined by the tubular body containing the bundle of hollow fibres. The hemo(dia)filtration apparatus 1 comprises an extracorporeal blood circuit having an arterial line 6 , or a blood removal line from the patient for the blood to be treated in the hemo(dia)filter 5 , and a venous line 7 , or patient return line for the blood treated in the hemo(dia)filter 5 . The hemo(dia)filtration apparatus 1 further comprises a blood pump 8 for circulation of blood in the extracorporeal circuit. The blood pump 8 is of a tube-deforming rotary type (peristaltic). The extracorporeal blood circuit further comprises the blood chamber of the hemo(dia)filter 5 . The arterial line 6 comprises an arterial patient end 9 , a pre-pump arterial expansion chamber 10 , a blood pump tube tract 11 , a post-pump arterial expansion chamber 12 , an arterial device end 13 . The venous line 7 comprises a venous device end 14 , a venous expansion chamber 15 , a venous patient end 16 . The dialysis machine is provided with an arterial clamp 17 operating on the arterial line 6 , in particular between the patient arterial end 9 and the pre-pump arterial expansion chamber 10 . The dialysis machine is provided with a venous clamp 18 operating on the venous line 7 , in particular between the patient venous end 16 and the venous expansion chamber 15 . The patient arterial end 9 , like the patient venous end 16 , is designed for connection (directly or via a vascular access device of known type) with a vascular access of a patient. The arterial clamp 17 , respectively the venous clamp 18 , serves for closing a squeezable tract of the arterial line 6 , respectively of the venous line 7 , on command of a control unit of the dialysis machine. The pre-pump arterial expansion chamber 10 , which is arranged downstream of the arterial clamp 17 (where “downstream” means with reference to the blood circulation direction during the treatment), serves for separating the air contained in the blood and for monitoring the arterial blood pressure (before the blood pump 8 ). The venous expansion chamber 15 , which is arranged upstream of the venous clamp 18 (where “upstream” means with reference to the blood circulation direction during the treatment), is for separating the air contained in the blood and for monitoring the venous blood pressure. The pre-pump arterial expansion chamber 10 , like the venous expansion chamber 15 , is designed to give rise to a liquid level separating a lower part full of liquid (blood) from an upper part full of gas (air). Each of the expansion chambers 10 and 15 is provided, for example superiorly, with a zone predisposed for pressure reading; this zone comprises, in the specific case, a membrane device, of known type, having a deformable elastic membrane with an internal surface in contact with the fluid (blood and/or air) contained in the chamber and an external surface operatively associable to a pressure sensor of the dialysis machine. The blood pump tube tract 11 , which is designed for removably coupling with the blood pump 8 , is open-ring conformed (in the specific embodiment it is U-shaped with a horizontal lie and with the convexity facing right, with reference to the viewpoint of a user situated in front of the front panel of the dialysis machine) with two ends, one for blood inlet and the other for blood outlet, fluidly and mechanically connected to two tubular extensions 19 ( FIG. 2 ) solidly connected to the pre-pump arterial expansion chamber 10 . The arterial device end 13 and the venous device end 14 are designed for removably coupling with an inlet port (in the specific embodiment, upper) and, respectively, an outlet port (in the specific embodiment, lower) of the blood chamber of the hemo(dia)filter 5 . The pre-pump arterial expansion chamber 10 and the venous expansion chamber 15 are integrated in a cartridge structure of known type.
The post-pump arterial expansion chamber 12 is inserted in the arterial line 6 between the blood pump 8 and the hemo(dia)filter 5 . The post-pump arterial expansion chamber 12 comprises a blood inlet port 20 , an infusion fluid inlet port 21 (in the present example of hemo(dia)filtration with pre-dilution, the infusion fluid, or infusate, can be replacement fluid, or substituate; in the following description the specific term “replacement fluid” and “substituate” will be used instead of more general terms like “infusion fluid” and “infusate”, without the generalised meaning being compromised), a mixing zone where the blood and replacement fluid are mixed, and an outlet port for the blood-fluid mixture 22 (where the replacement fluid is present in the mixture in case of pre-dilution and absent in case of no pre-dilution).
The post-pump arterial expansion chamber 12 serves to separate the air contained in the replacement fluid. The post-pump arterial expansion chamber 12 monitors the pressure in the replacement fluid supply line. The post-pump arterial expansion chamber 12 also serves to further separate the air contained in the blood along the arterial line 6 downstream of the blood pump 8 and for monitoring the blood pressure in the arterial line 6 between the blood pump and the hemo(dia)filter 5 . The post-pump arterial expansion chamber 12 is designed to produce a liquid level that separates a lower part which is full of liquid (blood or blood/replacement fluid mixture) and an upper part which is full of gas (air). The post-pump arterial expansion chamber 12 is provided, for example superiorly, with a zone predisposed for pressure detection; this zone comprises, in the present embodiment, a membrane device 58 , of known type, having a deformable membrane with an internal surface in contact with the fluid contained in the chamber and an external surface which is operatively associable to a pressure sensor of the dialysis machine. The post-pump arterial expansion chamber 12 will be described in greater detail herein below.
The hemo(dia)filtration apparatus 1 comprises a replacement fluid supply line 23 which provides, in this embodiment, the replacement fluid (substituate) to the extracorporeal blood circuit. The supply line 23 takes the dialysis fluid from the on-line port 4 and, after an ultrafiltration treatment to make it suitable as a replacement fluid, conveys it to the extracorporeal blood circuit.
The supply line 23 branches out from a main branch 24 into a pre-dilution branch 25 fluidly connected to the arterial line 6 and a post-dilution branch 26 fluidly connected to the venous line 7 . The replacement fluid supply line 23 comprises an inlet end 27 having a connector for removable connection with the on-line port 4 for sourcing the dialysis fluid supplied by the dialysis machine. Alternatively to an on-line port of a machine for dialysis fluid preparation, other fluid sources can be used, for example a ready-prepared dialysis fluid or replacement fluid recipient, or a centralised dialysis fluid supply system, supplying to various units.
The replacement fluid supply line 23 comprises an ultrafilter 28 predisposed fluidly in the main branch 24 upstream of the branch-out for ultrafiltering the dialysis fluid taken from the dialysis machine to render the fluid suitable for use as a replacement fluid. The ultrafilter 28 reduces the endotoxin percentage in the fluid. The ultrafilter 28 comprises a semipermeable membrane that separates a first chamber containing the fluid to be ultrafiltered (dialysis fluid) from a second chamber containing the ultrafiltered fluid (replacement fluid). The semipermeable membrane comprises, in the present embodiment, a bundle of hollow fibres. The first chamber of the fluid to be ultrafiltered comprises the inside of the hollow fibres, while the second chamber of the ultrafiltered fluid is defined between the outside of the hollow fibres and the tubular body enclosing the bundle of hollow fibres.
The ultrafilter 28 is further provided, for example superiorly, with a vent line of the air communicating with the first chamber of the fluid to be ultrafiltered and having a clamp (for example manually activated) for intercepting and a vent into the atmosphere protected by a protection device (for example a hydrophobic membrane).
The replacement fluid supply line 23 can further comprise a check valve predisposed fluidly in the main branch 24 upstream of the branch-out. The check valve, which in the present embodiment is not present, might be located after the ultrafilter 28 .
A tract of the replacement fluid pump tube 29 is predisposed in the supply line 23 for coupling with a replacement fluid circulation pump 30 . In to the present embodiment the replacement fluid pump 30 is a tube-deforming rotary pump (peristaltic). The replacement fluid pump tube tract 29 is open-ring shaped with an aspiration end and a delivery end. In particular the replacement fluid pump tube tract 29 is U-shaped, and, in the use configuration with the pump 30 , lies on a vertical plane, with the two end branches arranged horizontally (the convexity of the U is directed oppositely to the blood pump tube tract 11 , i.e. in the present embodiment to the left with reference to the viewpoint of a user situated in front of the front panel of the machine). The rotation axes of the two rotary pumps 8 and 30 are parallel to one another. The pump tube tract 29 , in the engaged configuration with the pump 30 , is arranged symmetrically to the blood pump tube tract 11 , with respect to a plane of symmetry (in the present embodiment, vertical) which is parallel to the rotation axes of the two rotary pumps 8 and 30 . The replacement fluid pump tube tract 29 is fluidly arranged in the main branch 24 upstream of the branch-out (where “upstream” means in reference to the circulation direction of the replacement fluid). The replacement fluid pump tube tract 29 is arranged fluidly upstream of the ultrafilter 28 .
The replacement fluid supply line 23 comprises an auxiliary connection 31 fluidly arranged after the ultrafilter 28 . This auxiliary connection 31 is branched out from the replacement fluid line 23 . The auxiliary line is further provided with a clamp 32 (for example a manually operated clamp) for closing the auxiliary line, and a protection hood for removable closure of the auxiliary line 31 . The auxiliary line branches off from the main branch 24 before the branch-out.
The auxiliary connection 31 is designed for removable fluid connection with the extracorporeal blood circuit, in particular with the arterial line 6 or the venous line 7 . The auxiliary connection 31 serves to fill the extracorporeal circuit with the replacement fluid, in particular during the circuit priming stage, i.e. during the stage preliminary to the treatment during which the air and any other undesirable particles contained in the blood circuit are evacuated and the circuit is filled with an isotonic liquid, for example a saline solution coming from a bag or, as in the present embodiment, with an isotonic fluid (dialysis fluid or saline) which is prepared by the dialysis machine, supplied to the on-line port 4 of the machine and ultrafiltered by crossing the replacement fluid supply line 23 . In the present embodiment the auxiliary connection 31 is removably couplable to the patient end of the arterial line 9 or to the patient end of the venous line 16 . The auxiliary connection 31 comprises, for example, a female luer connector couplable to a is male luer connector at the patient arterial 9 or venous 16 end.
At least one from among the three above-mentioned expansion chambers (arterial pre-pump 10 , arterial post-pump 12 and venous 15 ) is fluidly connected, in particular directly, to the pre-dilution branch 25 or the post-dilution branch 26 . In the present embodiment the post-pump arterial expansion chamber 12 is fluidly connected directly to the pre-dilution branch 25 .
The post-dilution branch 26 opens (directly) into a point of venous line 7 comprised between the hemo(dia)filter 5 and the venous chamber 15 . The venous chamber 15 therefore indirectly communicates, via a tract of venous line 7 , with the post-dilution branch 26 .
The aspiration and delivery ends of the replacement fluid pump tube tract 29 are rigidly connected to at least one from among the above-mentioned expansion chambers (arterial pre-pump 10 , arterial post-pump 12 and venous 15 ). In the present embodiment the aspiration and delivery ends of the replacement fluid pump tube tract 29 are connected rigidly to the post-pump arterial expansion chamber 12 . As mentioned, the expansion chamber bearing the replacement fluid pump tube tract 29 , i.e. the chamber 12 , is provided with a zone for monitoring the pressure which is predisposed for connection with a pressure sensor provided on the dialysis machine. This monitoring zone is provided with the pressure detecting device 58 .
Two tubular extensions for fluid and mechanical connection of the two ends of the pump tube tract 29 are solidly connected (for example are made in a single piece with the chamber itself) to the chamber 12 . The two tubular extensions are not fluidly connected to the chamber 12 , if not indirectly through other parts (for example the ultrafilter 28 ) of the fluid circuit transporting the replacement fluid.
The replacement fluid supply line 23 comprises a fluid communication system which is interpositioned fluidly between the delivery end of the replacement fluid pump tube tract 29 and the expansion chamber bearing the replacement fluid pump tube tract 29 (as mentioned in this case the expansion chamber bearing the pump tube tract 29 is the post-pump arterial expansion chamber 12 ). This fluid communication system comprises is one or more from the following elements: the ultrafilter 28 , the check valve (if present), the branch-out, and at least a tube tract which is flexible and closable by elastic deformation, in particular squeezing.
In the present embodiment, the fluid communication system, which places the replacement fluid pump tube tract 29 in communication with the extracorporeal blood circuit, comprises a first flexible tube 41 having a first end connected with a first tubular connection 42 which is rigidly connected to (but not fluidly communicating with) the post-pump arterial chamber 12 (the first tubular connection 42 is arranged inferiorly of the chamber 12 itself), and a second end which is opposite the first end and connected to a second tubular connection 43 for inlet of the ultrafilter 28 (the second tubular connection 43 for inlet is located inferiorly of the ultrafilter 28 and communicates with the chamber of the fluid to be ultrafiltered). Each of these tubular connections 42 and 43 faces downwards, with reference to an operative configuration of the apparatus 1 . Each of these tubular connections 42 and 43 has a longitudinal axis which extends, at least prevalently, in a vertical direction.
The above-described fluid communication system comprises the ultrafilter 28 and a second three-way flexible tube 44 having a first end which is connected to a tubular connection for outlet of the ultrafilter 28 (the tubular outlet connection is located on a side of the ultrafilter 28 itself, in particular superiorly, and communicates with the ultrafiltrate fluid chamber, i.e. with the outside of the hollow fibres), a second end (arranged superiorly and facing upwards) to which the auxiliary connection 31 is connected by means of the auxiliary line, and a third end (arranged inferiorly and facing downwards).
The above-mentioned three ends of the second flexible tube 44 are in reciprocal fluid communication (for example with reciprocal T or Y arrangement). The second three-way flexible tube 44 , which in the present embodiment is T-shaped with the first end arranged at 90° to the other two, is press-formed by injection of a soft plastic material.
The fluid communication system comprises a third three-way flexible tube 45 having a first end which is connected to the third end of the second flexible tube 44 , a second end connected to the inlet port 21 of the replacement fluid to the chamber 12 , and a third end connected to a zone of the venous line 7 arranged upstream of the venous expansion chamber 15 . In the present embodiment the first end is arranged superiorly (facing upwards), the third end is arranged inferiorly (facing downwards), while the second end is arranged obliquely (facing upwards) with respect to the other two, forming an angle which is less than a right-angle with the first upper end. The third three-way flexible tube 45 is made by press-forming by injection of a soft plastic material. The third three-way flexible tube 45 exhibits the branch-out in the pre-dilution branches 25 and the post-dilution branches 26 , which comprise two of the three ways of the third flexible tube 45 (in particular the ways that exhibit the second and third ends).
The hemodiafiltration apparatus 1 is made in two distinct modules which are fluidly connected one to the other. A first module A (on the right in FIG. 2 ) comprises an initial tract of arterial line 6 which goes from the patient arterial end 9 to the pre-pump expansion chamber 10 . The first module A further comprises the pre-pump expansion chamber 10 , the blood pump tube tract 11 and the venous expansion chamber 15 (integrated with the chamber 10 in the cartridge structure of known type). The first module A further comprises a final tract of venous line 7 which goes from the venous expansion chamber 15 to the patient venous end 16 . The first module A also comprises a tract of arterial line 6 which is arranged downstream of the blood pump 8 and which is integrated into the cartridge body structure. As mentioned, the cartridge structure, which incorporates the chambers 10 and 15 , supports the two ends, aspiration and delivery, of the blood pump tube tract 11 .
A second module B (on the left in FIG. 2 ) comprises the replacement fluid supply line 23 (starting from the inlet end 27 , and including the replacement fluid pump tube tract 29 , the ultrafilter 28 and the pre-dilution and post-dilution branches 25 and 26 ). The second module B further comprises the post-pump arterial expansion chamber 12 . Also included are an intermediate tract of arterial line 33 which fluidly connects an arterial outlet of the first module A (connected to an outlet of the blood pump tube tract) with an arterial inlet of the second module B (connected to the blood inlet of the post-pump arterial expansion chamber), and an intermediate tract of venous line 34 which fluidly connects a venous outlet of the second module B (connected with the post-dilution branch 26 ) with a venous inlet of the first module A (connected with an inlet of the venous expansion chamber).
The second module B comprises a support element to which the supply line of the replacement fluid 23 is constrained in order that the pre-dilution 25 and post-dilution branches 25 and 26 are positioned in a prefixed position with respect to the post-pump arterial expansion chamber. The correct and stable positioning of the pre-dilution and post-dilution branches 25 and 26 with respect to the front panel of the dialysis machine enables operatively efficient use of the above-said branches with two control valves, a pre-dilution control valve 52 and a post-dilution control valve 53 arranged on the front panel.
The support element comprises, in the present embodiment, one or more extensions 35 which emerge from the expansion chamber which bears the replacement fluid pump tube tract 29 (i.e. the post-pump arterial chamber 12 ). The extensions 35 emerge from a side of the chamber 12 located on the opposite side with respect to the replacement fluid pump tube tract 29 and extend in an opposite direction with respect to the extension of the pump tract 29 itself. The extensions 35 , in the present embodiment, are rigidly connected to the chamber 12 that bears the replacement fluid pump tube tract 29 . The extensions 35 , in the present embodiment, are made (for example by press-forming of plastic material) in a single piece with the chamber 12 itself. The support element further comprises a casing 36 engaged to one or more of the extensions 35 . The casing 36 in the present embodiment is joint-coupled to one or more of the extensions 35 . In particular the casing 36 is coupled to one or more of the extensions 35 in at least two joint zones. The casing 36 , made of plastic material, is provided with a front part which at least partially contains the tubular body of the ultrafilter 28 .
One of the extensions 35 exhibits a mounting extension 37 which, in collaboration with the two tubular extensions 38 for engagement of the ends of the replacement fluid pump tube tract 29 , serve for removably mounting the second module B on the front panel of the dialysis machine.
The pre-dilution 25 and post-dilution 26 branches each comprise at least a tract of flexible tube which can be obstructed by squeezing. These tracts of flexible tube are positioned in a prefixed position with respect to the post-pump arterial expansion chamber 12 . The correct positioning of the prefixed position is easily reached when mounting the module B on the front panel of the machine, by virtue of the fact that the fluid connection system formed by the second flexible tube 44 and the third flexible tube 45 are positioned stably with respect to the support element of module B, so that the pre-dilution 25 and post-dilution 26 branches (made from the third flexible tube 45 ) are immobile with respect to the support element of module B, although each of them is elastically deformable and therefore closable by squeezing of the valves 52 and 53 .
The branch from the pre-dilution 25 and post-dilution 26 branches which is not fluidly connected to the expansion chamber bearing the replacement fluid pump tube tract 29 can be constrained, directly or via a tract of the extracorporeal blood circuit, to the support element. In the present embodiment, in which the expansion chamber bearing the replacement fluid pump tube tract 29 is the post-pump expansion chamber 12 (which chamber 12 is connected to the pre-dilution branch 25 ), the post-dilution branch 26 can be constrained to the support element via a tract of venous line 7 of the extracorporeal blood circuit. In particular, a tract of venous line 7 is engaged in two recesses afforded in the casing 36 , and the post-dilution branch 26 is fluidly connected to this tract of venous line 7 .
The main branch 24 of the supply line 23 is constrained (for example directly, as in the present embodiment) to the support element. In particular the main branch 24 exhibits at least a support zone that interacts (in a gripping and/or direct contact coupling) with the support element in a tract to that is downstream of the ultrafilter 28 . In more detail, a tract of the main branch 24 arranged downstream of the ultrafilter 28 is engaged (by, for example, a removable joint) in a seating afforded on one of the extensions 35 . This tract of the main branch 24 (which in the present embodiment is part of the second flexible tube 44 ) exhibits, at the ends thereof, two annular projections which are axially distanced from one another and which are arranged externally of the opposite ends of the seating 46 , functioning as stable centring and positioning tabs of the tract of main branch 24 in the seating 46 .
The ultrafilter 28 is supportedly constrained to the support element of module B, in particular to the casing 36 .
The support element can realise at least a mechanical and not fluid interconnection between the expansion chamber bearing the replacement fluid pump tube tract 29 (i.e. the chamber 12 ) and the replacement fluid supply line 23 and/or between the expansion chamber bearing the replacement fluid pump tube tract 29 (chamber 12 ) and the extracorporeal blood circuit. A mechanical and not fluid interconnection can also be operating between the expansion chamber 12 and the venous line 7 (or the post-dilution branch 26 or, respectively, the arterial line 6 (or the pre-dilution branch 25 ).
One of these mechanical and not fluid interconnections comprises, in the present embodiment, one of the extensions 35 in the form of an arm that emerges (on the opposite side with respect to the replacement fluid pump tube tract 29 ) from the expansion chamber 12 which bears the replacement fluid pump tube tract. As already mentioned, this arm exhibits at an end thereof an attachment point (seating 46 ) for the main branch 24 of the supply line 23 . As already mentioned, the support element realises both the mechanical and not fluid interconnection between the chamber 12 and the line 23 , and the mechanical and not fluid interconnection between the chamber 12 and the blood circuit.
The support element of the second module B comprises, in the present embodiment, two elements which are assembled one to the other, i.e. the extensions 35 (integrated with the chamber 12 ) and the protection casing 36 . However it would be possible, in further embodiments of the invention, to have the support element made in an integrated single piece or an assembly of three or more distinct elements.
The second module B comprises an integrated element which defines the expansion chamber supporting the replacement fluid pump tube is tract 29 , i.e. the chamber 12 . This integrated element also defines a part of the support element of the second module B, in particular the extensions 35 .
The integrated element further defines a first conduit 39 for blood inlet into the expansion chamber 12 , a second conduit 50 for replacement fluid inlet, and a third conduit 40 for blood outlet (or blood mixed with replacement fluid) from the expansion chamber 12 .
The first and third blood conduit 39 and 40 belong to the extracorporeal blood circuit and are located on two opposite sides of the above-described expansion chamber 12 and extend in length in a vertical direction, with reference to an operative configuration in which the pump tube tract 29 is coupled to the replacement fluid circulation pump 30 .
The first and third blood conduits 39 , 40 also each have a bottom end which is fluidly connected to an expansion reservoir 47 of the post-pump arterial expansion chamber 12 , and an upper end which is fluidly connected (via the ports 20 and 22 ) to the rest of the arterial line 6 , respectively before and after the post-pump arterial expansion chamber 12 . In particular the first inlet conduit 39 is connected to an initial part of the arterial blood line 6 having the patient end 9 destined for connection with the arterial vascular access; the third outlet conduit 40 is connected to a final part of the arterial blood line 6 having the device end 13 destined for connection to the hemo(dia)filter 5 .
With reference to figures from 7 to 14 , the integrated element defining the chamber 12 is described in greater detail. The chamber 12 comprises the expansion reservoir 47 which is provided with a bottom, a top, at least a first side extending between the bottom and the top, a first access 48 arranged on the first side at a distance from the bottom and top, and a second access 49 .
The first conduit 39 terminates in the first access 48 . A second conduit 50 terminates in the first conduit 39 or, as in the present embodiment, in the expansion reservoir 47 . The first conduit 39 and the second conduit 50 terminate in the first access 48 with, respectively, a first flow direction and a is second flow direction which are incident to one another.
The first conduit 39 terminates in the first access 48 with a first flow direction having at least a motion component directed towards the bottom. The first flow direction has at least a motion component directed towards a second side of the expansion reservoir 47 ; the second side extends between the bottom and top and is opposite the first side.
The second conduit 50 terminates in the expansion reservoir 47 with a second flow direction having at least a motion component directed towards the second side of the expansion reservoir 47 . The second flow direction has at least a motion component directed towards the top. The second flow direction has at least a first motion component that is horizontal and directed towards the inside of the expansion reservoir 47 .
The second conduit 50 comprises an intermediate tract 59 having a flow direction provided with at least a second horizontal motion component going in an opposite direction to the first horizontal motion component. The flow direction of the intermediate tract 59 is provided with at least a vertical motion component.
The first conduit 39 has a diverging tract 51 with a fluid passage that broadens in the direction of the first access 48 . The diverging tract 51 broadens towards the bottom of the reservoir 47 . The expansion reservoir 47 extends prevalently on a lie plane; the diverging tract 51 enlarges prevalently in a perpendicular direction to the lie plane. The diverging tract 51 terminates at the first access 48 .
The first access 48 is elongate and extends in a perpendicular direction to the first side of the reservoir 47 .
The second access 49 is arranged on the bottom of the reservoir 47 . The third conduit 40 terminates in the second access 49 . The third conduit 40 extends in length by the side of the second side of the expansion reservoir 47 .
The first conduit 39 terminates in the first access 48 with a first flow direction directed towards the second access 49 . The first flow direction has at least a motion component which is direction towards the bottom.
The second conduit 50 terminates on the first side of the expansion reservoir 47 below the end of the first conduit 39 . The second conduit 50 terminates either in the first access 48 contiguously below the end of the first conduit 39 (as in the present embodiment), or, in a further embodiment, not illustrated, it terminates in an intermediate access arranged between the first access 48 and the bottom of the reservoir 47 .
The expansion reservoir 47 has an upper part, comprised between the first access 48 and the top, having a greater width than a lower part comprised between the bottom and the first access 48 .
The first conduit 39 meets the second conduit 50 in a connecting zone, and joins the connecting zone in a position above the second conduit 50 .
The first conduit 39 extends lengthwise by the side of the first side of the reservoir 47 . The first conduit 39 is designed to introduce the transported flow (in the present embodiment the arterial blood) into the connecting zone with at least one motion component directed in a downwards direction. The second conduit 50 is designed to introduce the transported flow (in this case the replacement fluid) into the connecting zone with at least a motion component directed upwards. The first conduit 39 and the second conduit 50 are designed so that each of the respective transported flows is introduced into the connecting zone with at least a horizontal motion component directed internally of the expansion reservoir 47 .
The first conduit 39 and the second conduit 50 are arranged on a same side (the first side) of the expansion reservoir 47 . The first conduit 39 is situated above the second conduit 50 .
The first side of the expansion reservoir 47 has an upper zone with a vertical inclination, and a lower zone with an oblique inclination. The oblique lower zone of the first side is inclined in a direction nearing the second side. This oblique inclination determines a narrowing of the expansion reservoir 47 . The zone of the second side that is facing the oblique zone of the first side is substantially vertically oriented. The first conduit 39 has an upper tract having a substantially vertical longitudinal axis, and a lower tract having an oblique longitudinal axis. The oblique axis is inclined in a direction nearing the second side of the expansion reservoir 47 . The first conduit 39 terminates in the expansion reservoir 47 with an oblique inclination.
The first conduit 39 is made in a single piece with the expansion reservoir 47 . The second conduit 50 is made in a single piece with the expansion reservoir 47 . The third conduit 40 is made in a single piece with the expansion reservoir 47 . The chamber 12 is realised by assembly of two half-shells. The two half-shells are obtained by press-forming of a plastic material.
The extracorporeal blood line which includes the chamber 12 is, in the present embodiment, the arterial line 6 . The chamber 12 can, however, be associated (alternatively or in addition to the arterial line 6 ) to the venous line 7 . The chamber 12 in this case would be a mixing chamber for replacement fluid (in post-dilution) for degassing and for monitoring pressure, arranged downstream of the hemo(dia)filter; the inlet port 20 would be connected to the hemo(dia) filter 5 , while the outlet port 22 would be connected to the vascular access.
During treatment, in which the arterial line 6 and the venous line 7 are connected to the patient, the blood pump 8 is activated, so that the blood is removed from the patient via the arterial line 6 , is sent to the hemo(dia)filter 5 , and is returned to the patient via the venous line 7 . The replacement fluid pump 30 is also activated, so that the dialysis fluid is removed from the on-line port 4 of the machine, is made to pass first through the pump tube tract 29 and then the ultrafilter 28 , and is then sent selectively to the chamber 12 on the arterial line 6 (opening the pre-dilution valve 52 operating on the branch 25 and closing the post-dilution valve 53 operating on the branch 26 ) or to the venous line 7 (valve 52 closed and valve 53 open), or to both (valves 52 and 53 both open).
In a case of pre-dilution, the replacement fluid flow enters the expansion reservoir 47 from below, transversally encountering the blood flow that enters the reservoir from above. Both flows are obliquely directed, each with an inlet component into the expansion reservoir 47 which is horizontally directed (with reference to the work position of the chamber 12 ) towards the second side of the expansion reservoir 47 , and a vertical component having an opposite direction to the direction of the flow. The meeting of the two flows causes an effective remixing between the blood and the replacement fluid, so that the mixed liquid (blood and replacement fluid) that exits through the third conduit 40 is homogeneously mixed.
The special conformation and arrangement of the chamber 12 enables both an effective remixing of the blood and replacement fluid and an effective degassing of the liquids entering the expansion reservoir 47 , especially the replacement fluid, thus preventing any air bubbles exiting through the third conduit 40 .
In the absence of pre-dilution (valve 52 closed), the replacement fluid does not reach the chamber 12 , while the blood enters through the first conduit 39 and exits through the third conduit 40 ; since the first conduit 39 terminates directly facing the inlet of the third conduit 40 , the turbulence created is relatively low, reducing to a minimum the formation of foam and flow resistors, while at the same time enabling separation of the air which may still be present in the blood.
Before the treatment is performed the circuit is primed by connecting the patient venous end 16 to the connector 31 and the patient arterial end 9 to a discharge (for example a collection bag or a discharge connected to the exhausted fluid circuit of the dialysis machine). Then the clamp 32 is opened, the valves 52 and 53 are closed, the pump 8 is activated (with the tract 29 not coupled to the pump 30 ) in order to aspirate fluid from the port 4 and to circulate the fluid along the venous line 7 , the blood filter of the hemodiafilter 5 , and the arterial line 6 up to the end 9 . The priming of the post-dilution branch 26 is performed by activating the pump 8 , closing the venous clamp 18 and opening the valve 53 (with the valve 52 closed), while the priming of the pre-dilution branch 25 is done by opening the valve 52 (with the venous clamp 18 and the valve 53 closed).
In a further embodiment (not shown) the support element comprises a selector configured to selectively squeeze the flexible tube tracts of the pre-dilution and post-dilution branches. The selector comprises a movable (e.g. rotatable) member mounted on (e.g. rotatably coupled to) the support element. The movable member includes a first end and a second end and can assume at least two configurations. In a first configuration the first end squeezes one of the flexible tube tracts and in a second configuration the second end squeezes the other of the flexible tube tracts.
LEGEND
1 . Hemo(dia)filtration apparatus
2 . Fresh dialyser fluid port
3 . Exhausted fluid port
4 . On-line port
5 . Hemo(dia)filter
6 . Arterial line
7 . Venous line
8 . Blood pump
9 . Patient arterial end
10 . Pre-pump arterial expansion chamber
11 . Blood pump tube tract
12 . Post-pump arterial expansion chamber
13 . Arterial device end
14 . Venous device end
15 . Venous expansion chamber
16 . Venous patient end
17 . Arterial clamp
18 . Venous clamp
19 . Tubular extensions connected to the chamber 10 for attachment of the blood pump tube tract 11
20 . Blood inlet port of the post-pump arterial expansion chamber
21 . Replacement fluid inlet port of the post-pump arterial expansion chamber 12
22 . Outlet port for blood(-replacement fluid) from post-pump arterial expansion chamber 12
23 . Replacement fluid supply line
24 . Main branch of line 23
25 . Pre-dilution branch of line 23
26 . Post-dilution branch of line 23
27 . Inlet end of line 23
28 . Ultrafilter of replacement fluid
29 . Replacement fluid pump tube tract
30 . Replacement fluid pump
31 . Auxiliary connection of line 23 (for priming)
32 . Auxiliary connection 31 intercept clamp
33 . Intermediate tract of arterial line between the two modules of the hemodiafiltration apparatus
34 . Intermediate tract of venous line between the two modules of the hemodiafiltration apparatus
35 . Support extensions emerging from the post-pump arterial expansion chamber
36 . Casing
37 . Mounting extension
38 . Tubular extensions for supporting the replacement fluid tube tract
39 . First conduit for blood inlet into the post-pump arterial expansion chamber
40 . Third blood outlet conduit of the post-pump arterial expansion chamber
41 . First flexible tube
42 . First tubular connection
43 . Second tubular connection
44 . Second flexible tube
45 . Third flexible tube
46 . Seating predisposed on the support element for fixing the main branch 24
47 . Expansion reservoir
48 . First access of reservoir 47
49 . Second access of reservoir 47
50 . Second inlet conduit of replacement fluid into the post-pump arterial expansion chamber
51 . Diverging tract of the first conduit 39
52 . Pre-dilution control valve
53 . Post-dilution control valve
54 . Connection for service line located at top of expansion reservoir 47
55 . Connection for an ultrafilter vent line
56 . Connection for the auxiliary line provided with the auxiliary connector 31
57 . Connection for an end of the initial tract of replacement fluid line 23 having the inlet 27 at the opposite end
58 . Device for detecting pressure in the blood chamber 12
59 . Intermediate tract of second conduit 50 | An extracorporeal blood chamber ( 12 ) comprises an expansion reservoir ( 47 ) having a first access ( 48 ) arranged laterally and a second access ( 49 ) arranged on the bottom of the chamber ( 12 ). The chamber comprises, integrally with the reservoir, a first conduit terminating in the first access, a second conduit terminating in the first access, and a third conduit terminating in the second access. The extracorporeal blood enters the reservoir through the first conduit and there mixes with an infusion fluid which enters through the second conduit. The resulting mixture exits through the third conduit. The chamber is used in a hemo(dia)filtration apparatus to mix the blood optimally with the replacement fluid. | 0 |
Pursuant to 35 U.S.C. §119, this application claims the benefit of U.S. Provisional Application Serial No. 60/250,754, entitled FORMATION ISOLATION VALVE,” filed on Dec. 1, 2000.
BACKGROUND
The invention generally relates to a formation isolation valve.
A formation isolation valve may be located downhole to form a sealed access to a particular formation. In this manner, the formation isolation valve may be opened or run open so that a tubular string may be run downhole through the valve to permit the string to perform one or more downhole functions below the formation isolation valve. After these functions are complete, the string may be retrieved. After the end of the string passes through the valve during the retrieval of the string, the valve may then be operated to seal off the formation below the valve. In this manner, a shifting tool may be located at the end of the tool to physically engage the valve to cause the valve to close. The shifting tool may also be used to open the valve.
As an example, the string may include a gravel packing tool to route gravel into an annular region that surrounds a screened portion of a production tubing of the well. In this manner, the gravel travels down a central passageway of the string and through radial ports of the gravel packing tool into the annular region. The gravel may include sand that falls between the interior opening of the formation isolation valve and the outside of the string to create friction between the string and the valve. Unfortunately, the friction between the string and valve may cause the string to unintentionally physically engage the valve to cause the valve to prematurely close on the string. Thus, such a scenario may cause the string to become wedged in the valve.
Thus, there is a continuing need for an arrangement that addresses one or more of the problems that are stated above.
SUMMARY
In an embodiment of the invention, an assembly that is usable in a subterranean well includes a valve, a sleeve and an index mechanism. The valve is adapted to selectively isolate a region of the well, and the sleeve is adapted to be moved by a downhole tool to cause the valve to transition from a first state to a second state. The index mechanism prevents the valve from transitioning from the first state to the second state until after a position of the sleeve follows a predefined pattern.
Advantages and other features of the invention will become apparent from the following description, drawing and claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a formation isolation valve assembly according to an embodiment of the invention.
FIGS. 2, 3 , 4 , 6 , 7 and 8 are more detailed schematic diagrams of sections of the formation isolation valve assembly according to an embodiment of the invention.
FIGS. 5 and 9 are schematic diagrams of flattened portions of the formation isolation valve assembly depicting J-slots according to different embodiments of the invention.
FIG. 10 is a schematic diagram of a portion of a production tubing according to an embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1, an embodiment 10 of a formation isolation valve assembly in accordance with the invention controls access to a region of a well below the valve 10 . In this manner, the valve assembly 10 permits a string, such as a string 30 , to pass through the valve assembly 10 to the region beneath the valve assembly 10 when the valve assembly 10 is in an open state (as depicted in FIG. 1 ), and when the valve assembly 10 is in a closed state, the valve assembly 10 seals off communication with the region beneath the valve assembly 10 . An annular region, or annulus 11 , that is located between an exterior surface of the valve assembly 10 and a production tubing 9 of the well may be sealed off by a packer (not shown).
More specifically, in some embodiments of the invention, the valve assembly 10 includes a ball valve 22 that assumes an open state to permit the string 30 to pass through the valve assembly 10 and assumes a closed state to seal off the region below the valve assembly 10 when the string 30 no longer extends through the ball valve 22 .
In some embodiments of the invention, when the formation isolation valve assembly 10 is first set in place downhole, the ball valve 22 may be opened (or run into the well bore open) to permit the string 30 to pass through. Alternatively, the formation isolation valve assembly 10 may be run with the string 30 already included through the ball valve 22 . The string 30 may include a gravel packing tool to perform gravel packing operations downhole. After the gravel packing operations are complete, the string 30 may be withdrawn from the well bore.
In some embodiments of the invention, after the gravel packing operation is complete, the ball valve 22 is closed. In this manner, the string 30 may include a shifting tool 16 (near a lower end of the string 30 ) to physically close the ball valve 22 . More specifically, after lower end of the string 30 is retracted above the ball valve 22 , a profiled section 17 of the shifting tool 16 engages (as described below) the valve assembly 10 and is operated in a manner (described below) to cause the ball valve 22 to close.
After the string 30 is withdrawn from the well bore and the gravel packing operations are complete, pressure tests may be conducted downhole. At the conclusion of the pressure tests, a pressure may be used (as described below) to reopen the ball valve 22 .
For purposes of preventing unintentional opening and closing of the ball valve 22 , the valve assembly 10 includes two index mechanisms 15 and 20 , in some embodiments of the invention. The index mechanism 15 is pressure actuated and prevents the unintentional opening of the ball valve 22 without the occurrence of a predetermined number of pressurization/de-pressurization cycles, as described below. The index mechanism 20 is actuated via physical contact between the shifting tool 16 and the valve assembly 10 and prevents the unintentional closing of the ball valve 22 without a predetermined pattern of engagement, described below. Without the index mechanism 20 , movement of the shifting tool 16 or movement of the string 30 itself may unintentionally engage the closing mechanism of the valve assembly 10 to cause the ball valve assembly 10 to attempt to prematurely close, a condition that may cause the string 30 to become jammed in the ball valve 22 , thereby preventing the removal of the string 30 from the well.
More particularly, in some embodiments of the invention, the valve assembly 10 includes an operator mandrel 12 that moves up in response to applied tubing pressure (in the central passageway of the assembly 10 ) and moves down when the pressure is released. The downward travel of the mandrel 12 is limited by the index mechanism 15 until a predetermined number of cycles occur in which the tubing pressure increases and then decreases. After the predetermined number of cycles, the index mechanism 15 permits the mandrel 12 to travel downward to contact a collet actuator 13 that is engaged with a ball valve operator mandrel 14 that, in turn, operates the ball valve 22 . In this manner, the downward movement of mandrel 12 causes the mandrel 14 to move in a downward direction to open the ball valve 22 .
In some embodiments of the invention, to close the ball valve 22 via the shifting tool 16 , the profile 17 of the shifting tool 16 engages (as described below) the collet actuator 13 to force the collet actuator 13 up and down. On each upward stroke, the collet actuator 13 disengages from the mandrel 14 , as described below.
When the mandrel 14 moves up by a sufficient distance, the mandrel 14 closes the ball valve 22 . However, the upward travel of the mandrel 14 is limited by the index mechanism 20 until the shifting tool 16 forces the collet actuator 13 up and down for a predetermined number of cycles. After the cycles occur, the mandrel 14 engages with the collet actuator 13 on the downstoke on the sleeve 13 and remains engaged with the collet actuator 13 on the upstroke of the collet actuator 13 , thereby permitting the shifting tool 16 to lift the mandrel 14 up for a sufficient distance to close the ball valve 22 .
Referring to the formation isolation valve assembly 10 in more detail, FIGS. 2, 3 and 4 depict sections 10 A, 10 B and 10 C that form a section (of the valve assembly 10 ) that houses the index mechanism 15 and the mandrel 12 . The upper part of this section is formed from an upper housing section 44 a that mates with a lower housing section 44 b . In this manner, the lower end of the housing section 44 a is received into a bore in the upper end of the housing section 44 b . Both housing sections 44 a and 44 b are generally cylindrical and circumscribe a longitudinal axis of the valve assembly 10 .
The mandrel 12 moves up in response to applied tubing pressure in a central passageway 40 of the valve assembly 10 , and moves down in response to the pressure exerted by a nitrogen gas chamber 47 (FIG. 3 ). The nitrogen gas chamber 47 , in some embodiments of the invention, is formed from an annularly recessed cavity located between the housing section 44 a and the mandrel 12 . The nitrogen gas chamber 47 , in other embodiments of the invention, may be replaced by a coil spring or another type of spring, as examples.
The responsiveness of the mandrel 12 to the tubing pressure and the pressure that is exerted by the gas in the chamber 47 is attributable to an upper annular surface 50 (of the mandrel 12 ) that is in contact with the nitrogen gas in the nitrogen gas chamber 47 and a lower annular surface 51 of the mandrel 14 that is in contact with the fluid in the central passageway 40 . Therefore, when the fluid in the central passageway 40 exerts a force (on the lower annular surface 51 ) that is sufficient to overcome the force that the gas in the chamber 47 exerts on the upper annular surface 50 , a net upward force is established on the mandrel 12 . Otherwise, a net downward force is exerted on the mandrel 12 to force the ball valve operator mandrel 14 down.
Referring to FIG. 4, the index mechanism 15 limits the upward and downward travel of the mandrel 12 . More particularly, the index mechanism 15 confines the lower travel limit of the mandrel 12 until the mandrel 12 has made a predetermined number (eight or ten, as examples) of up/down cycles. In this context, an up/down cycle is defined as the mandrel 12 moving from a limited (set by the index mechanism 15 ) down position to a limited up position (set by the index mechanism 15 ) and then back down to the limited down position. A particular up/down cycle may be attributable to a pressure test in which the pressure in the central passageway 40 is increased and then after testing is completed, released.
After the mandrel 12 transitions through the predetermined number of up/down cycles, the index mechanism 15 no longer confines the downward travel of the mandrel 12 . Therefore, when the central passageway 18 is pressurized again, the mandrel 12 is free to travel down to contact the mandrel 14 to open the valve 22 .
Referring to FIG. 3, the mandrel 12 includes an exterior annular notch to hold O-rings 53 to seal off the bottom of the gas chamber 47 . O-rings 39 are also located in an interior annular notch of the housing section 44 a (see FIG. 3) to form a seal between the housing section 44 a and the mandrel 12 to seal off the nitrogen gas chamber 47 . O-rings 38 form a seal between the housing sections 44 a and 44 b.
Referring back to FIG. 4, in some embodiments of the invention, the index mechanism 15 includes an index sleeve 94 that is coaxial with the longitudinal axis of the valve assembly 10 , circumscribes the mandrel 12 and is circumscribed by the housing section 44 c . The index sleeve 94 includes a generally cylindrical body 97 that is coaxial with the longitudinal axis of the valve assembly 10 and is closely circumscribed by the housing section 44 c . The index sleeve 94 includes protruding splines, or members 104 (one being shown in FIG. 4 ), that radially extend from the body 97 toward the mandrel 12 to serve as a stop to limit the downward travel of the mandrel 12 until the mandrel 12 moves through the predetermined number of up/down cycles.
More specifically, the protruding members 104 are radially spaced apart around the longitudinal axis of the valve assembly 10 so that when the index sleeve 94 is rotated to the appropriate position after the predetermined number of up/down cycles, radially spaced protruding members 102 (two being shown in FIG. 4) of the mandrel 12 that radially extend from the mandrel 12 toward the index sleeve 94 pass between the protruding members 104 of the index sleeve 94 . Otherwise, the protruding members 104 limit the downward travel of the mandrel 12 , as the protruding members 102 and 104 contact each other.
Each up/down cycle of the mandrel 12 rotates the index sleeve 94 about the longitudinal axis of the valve assembly 10 by a predetermined angular displacement. After the predetermined number of up/down cycles, the protruding members 102 of the mandrel 12 are completely misaligned with the protruding members 104 of the index sleeve 94 , thereby allowing the mandrel 12 to pass through.
Referring both to FIG. 4 and FIG. 5 (that depicts a flattened portion 12 A of the mandrel 12 ), in some embodiments of the invention, a J-slot 105 may be formed in the mandrel 12 to establish the indexed rotation of the index sleeve 94 . In this J-slot arrangement, one end of an index pin 92 (see FIG. 4) is connected to the index sleeve 94 . The index pin 92 extends through a particular protruding member 104 in a radially inward direction from the index sleeve 94 toward the mandrel 12 so that the other end of the index pin 92 resides in the J-slot 105 . As described below, for purposes of preventing rotation of the mandrel 12 , a pin 90 radially extends from the housing section 44 c into a groove (of mandrel 12 ) that confines movement of the mandrel 12 to translational movement along the longitudinal axis of the valve assembly 10 , as described below.
As depicted in FIG. 5, the J-slot 105 includes upper grooves 108 (grooves 108 a , 108 b and 108 c , as examples) that are located above and are peripherally offset from lower grooves 106 (groove 106 a , as an example) of the J-slot 105 . All of the grooves 108 and 106 are aligned with the longitudinal axis of the valve assembly 10 . The upper 108 and lower 106 grooves are connected by diagonal grooves 107 and 109 . Due to this arrangement, each up/down cycle of the mandrel 12 causes the index pin 92 to move from the upper end of one of the upper grooves 108 , through the corresponding diagonal groove 107 , to the lower end of one of the lower grooves 106 and then return along the corresponding diagonal groove 109 to the upper end of another one of the upper grooves 108 . The traversal of the path by the index pin 90 causes the index sleeve 94 to rotate by a predetermined angular displacement.
The following is an example of the interaction between the index sleeve 94 and the J-slot 105 during one up/down cycle. In this manner, before the mandrel 12 transitions through any up/down cycles, the index pin 92 resides at a point 114 that is located near the upper end of the upper groove 108 a . Subsequent pressurization of the fluid in the central passageway 18 causes the mandrel 12 to move up and causes the index sleeve 94 to rotate. More specifically, the rotation of the index sleeve 94 is attributable to the translational movement of the index pin 92 with the mandrel 12 , a movement that, combined with the produced rotation of the index sleeve 94 , guides the index pin 92 through the upper groove 108 a , along one of the diagonal grooves 107 , into a lower groove 106 a , and into a lower end 115 of the lower groove 106 a when the mandrel 12 has moved to its farther upper point of travel. The downstroke of the mandrel 12 causes further rotation of the index sleeve 94 . This rotation is attributable to the downward translational movement of the mandrel 12 and the produced rotation of the index sleeve 94 that guide the index pin 92 from the lower groove 106 a , along one of the diagonal grooves 109 and into an upper end 117 of an upper groove 108 b . The rotation of the index sleeve 94 on the downstroke of the mandrel 12 completes the predefined angular displacement of the index sleeve 94 that is associated with one up/down cycle of the mandrel 12 .
At the end of the predetermined number of up/down cycles of the mandrel 12 , the index pin 92 rests near an upper end 119 of the upper groove 108 c . In this manner, on the next up stroke, the index pin 92 moves across one of the diagonal grooves 107 down into the lower end 116 of a lower groove 110 . The resulting rotation of the index sleeve 94 causes the protruding members 102 of the mandrel 12 to become completely misaligned with the protruding members 104 of the index sleeve 94 . Therefore, on the subsequent downstroke, the index pin 92 effectively travels up into the upper groove 112 as the mandrel 14 travels in a downward direction to open the packer isolation valve.
The index pin 90 (see also FIG. 4) always travels in the upper groove 112 . Because the index pin 90 is secured to the housing section 19 , this arrangement keeps the mandrel 12 from rotating during the rotation of the index sleeve 94 .
FIGS. 6 and 7 depict sections 10 D and 10 E (of the valve assembly 10 ) that include the collet actuator 13 , the ball valve operator mandrel 14 and the index mechanism 20 . The sections 10 D and 10 E are formed by the housing sections 44 c , 44 d and 44 e , each of which circumscribes the longitudinal axis of the valve 20 . In this manner, the lower end of the housing section 44 c is received by a bore located in the upper end of the housing section 44 d . The housing sections 44 c and 44 d are sealed together via O-rings 213 that are located in an exterior annular notch of the housing section 44 c . The lower end of the housing section 44 d is received by a bore located in the upper end of the housing section 44 d . The housing sections 44 d and 44 e are sealed together via O-rings 321 that are located in an exterior annular notch of the housing section 44 d.
In some embodiments of the invention, when the shifting tool 16 closes the ball valve 22 (after gravel packing operations, for example), the collet actuator 13 is engaged with the mandrel 14 and has a higher position than depicted in FIGS. 6 and 7. In this higher position, the mandrel 14 closes the ball valve 22 and subsequent action by the mandrel 12 is required to open the ball valve 22 . More specifically, a collet sleeve 206 is mounted to the collet actuator 13 to lock the collet actuator 13 and mandrel 14 (that is at this point engaged with the mandrel 14 ) into a position that keeps the ball valve 22 closed until the mandrel 12 forces the collet actuator 13 and mandrel 14 in a downward direction at the end of pressure testing operations, as described above.
The collet sleeve 206 is attached to the collet actuator 13 via a pin 200 , circumscribes a portion of the collet actuator 13 , and is located between the collet actuator 13 and the housing section 44 c . When the collet actuator 13 is in its upper position in which the ball valve 22 is closed, the ends of upper fingers 215 of the collet sleeve 206 are located in an annular notch 214 that is formed in an interior surface of the housing section 44 c . However, when the collet actuator 13 is forced in a downward direction, the beveled profile of the notch 214 causes the upper fingers 215 to be forced out of the notch 214 and extend through openings 208 of the collet actuator 13 , thereby permitting the collet actuator 13 and mandrel 14 to travel down.
However, before the mandrel 14 may move freely to close the ball valve 22 after gravel packing operations are complete, the index mechanism 20 is engaged to prevent unintentional closing of the ball valve 22 on the string 30 . A predetermined number of up and down cycles of the collet actuator 13 disengages the index mechanism 20 so that the mechanism 20 no longer restricts travel of the mandrel 14 .
Referring to FIG. 7, thus, when the index mechanism 20 is engaged and the ball valve 22 is open, the index mechanism's restriction on the upward travel of the mandrel 14 causes the collet actuator 13 to disengage, or separate, from the mandrel 14 on upstrokes until the collet 13 cycles through the predetermined number of up/down cycles.
To regulate the closing of the ball valve 22 , the index mechanism 20 includes an index sleeve 294 . The index sleeve 294 is coaxial with the longitudinal axis of the valve assembly 10 , circumscribes the collet actuator 13 and is circumscribed by the housing section 44 d . The index sleeve 294 is prevented from upward and downward movement via a lower shoulder 217 (see FIG. 6) of the housing section 44 c and a shoulder 305 (see FIG. 7) of the housing section 44 d . The index sleeve 294 includes a generally cylindrical body 297 that is coaxial with the longitudinal axis of the valve assembly 10 and is closely circumscribed by the housing section 44 d . The index sleeve 294 includes protruding splines, or members 302 (one being shown in FIG. 7 ), that radially extend inwardly from the body 297 to serve as a stop to limit the upward travel of the mandrel 14 until the shifting tool 16 moves the collet actuator 13 up and down a predetermined number of times. The downward travel of the mandrel 14 is limited by the shoulder 305 of the housing section 44 d.
More specifically, the protruding members 302 are radially spaced apart so that when the index sleeve 294 is rotated to the appropriate position, radially spaced protruding members 304 (of the mandrel 14 ) that extend radially outwardly from the mandrel 14 toward the index sleeve 294 pass between the protruding members 302 of the index sleeve 294 . When the mandrel 14 is pulled up with the collet actuator 13 to close the ball valve 22 , the index sleeve 294 is positioned to allow the protruding members 304 to pass between the protruding members 302 , as described below. In one embodiment, the protruding members 302 , 304 remain thus aligned to allow the subsequent axial movement of mandrel 14 .
Each time the shifting tool 16 moves the collet actuator 13 up or down, the index sleeve 294 rotates about the longitudinal axis of the valve assembly 10 by a predetermined angular displacement. After the predetermined number of up and down movements by the collet actuator 13 , the protruding members 304 of the mandrel 14 are completely misaligned with the protruding members 302 of the index sleeve 294 , thereby allowing the mandrel 14 to pass through to move in an upward direction to close the ball valve 22 .
In some embodiments of the invention, a J-slot 404 (see also FIG. 9 that depicts a flattened portion 314 of the collet actuator 13 ) may be formed in the collet actuator 13 to establish the indexed rotation of the index sleeve 294 . In this J-slot arrangement, one end of an index pin 292 (see FIG. 7) is connected to the index sleeve 294 . The index pin 292 extends radially inwardly so that the other end of the index pin 292 resides in the J-slot 404 in the collet actuator 13 . For purposes of preventing rotation of the collet actuator 13 , a pin 291 radially extends from the housing section 44 d into a longitudinal groove of the mandrel 14 , and a pin 298 radially extends inwardly from the mandrel 14 into a longitudinal groove of the collet actuator 13 . Thus, the pin 291 confines movement of the mandrel 14 to translational movement along the longitudinal axis of the valve assembly 10 , and the pin 298 confines movement of the collet actuator 13 to the translational movement along the longitudinal axis of the valve assembly 10 .
Therefore, due to the above-described arrangement, each time the collet actuator 13 moves in a downward direction, the index sleeve 294 rotates by a predetermined angular displacement, and each time the collet actuator 13 moves in an upward direction, the index sleeve 294 rotates by a predetermined displacement. Eventually, the index sleeve 294 does not restrict the upward travel of the mandrel 14 and permits the mandrel 14 to be pulled up enough to close the ball valve 22 .
Referring to FIG. 6, for purposes of allowing the shifting tool 16 to engage the collet actuator 13 to move the collet actuator 13 up and down, the collet actuator 13 has an interior annular upper groove 250 and an interior annular lower groove 252 that each have beveled cross-sections. The upper groove 250 has the openings 208 (two being depicted in FIG. 6) through which the end of the upper fingers 215 of the collet sleeve 206 extend to catch the shifting tool 16 to permit the tool 16 to lift the collet actuator 13 to the height that is allowed by the index pin 292 . When the collet actuator 13 travels in an upward direction, the upper fingers 215 are received by an upper annular groove 214 formed on the interior surface of the housing section 44 c . When received by the groove 214 , the upper fingers 215 retract to release the grip on the shifting tool 16 . The lower groove 252 has openings 209 (two being depicted in FIG. 6) through which the ends of lower fingers 211 of the collet sleeve 206 extend to catch the shifting tool 16 to permit the tool 16 to shift the collet actuator 13 back down. When the collet actuator 13 travels in a downward direction, the lower fingers 211 are received by an annular groove 212 that is formed in the interior surface of the housing section 44 c . When received by the groove 212 , the lower fingers 211 retract to release their grip on the shifting tool 16 .
Referring to FIGS. 7 and 8, in some embodiments of the invention, the collet actuator 13 includes fingers, such as a finger 324 that is depicted in FIG. 7, that includes an exterior annular ridge 320 that is received by a corresponding beveled interior annular notch 322 of the mandrel 14 . Thus, as long as the index sleeve 294 restricts the upward travel of the mandrel 14 , the upward force that is applied on the collet actuator 13 by the shifting tool 16 dislodges the collet actuator 13 from the mandrel 14 and allows the collet actuator 13 to proceed upwardly by itself. When the collet actuator 13 is one again moved downwardly by the shifting tool 16 , the exterior annular ridge 320 is once again received by the annular notch 322 . As depicted in FIG. 8, the mandrel 14 extends to operate the ball valve 22 that is housed in a lower section 10 F of the valve assembly 10 .
Once the index pin 292 enters the final, longitudinal groove 407 (see FIG. 9) of the J-slot 404 , the index sleeve 294 no longer restricts the upward travel of the mandrel 14 . Thus, the ridge 320 /notch 322 connection will not disengage when the collet actuator 13 is moved upward (or downward), and the upward movement of the collet actuator 13 also results in the upward movement of mandrel 14 . Based on the now “fixed” connection between the mandrel 14 and collet actuator 13 , the shifting tool 16 may be used to close the ball valve 22 by pulling the collet actuator 13 up and open the ball valve by shifting the collet actuator 13 down, as the index mechanism 20 is effectively disabled after cycling once through the above-described sequence. It is noted that the J-slot 404 may be designed to require any number of up/down cycles by the collet actuator 13 before releasing the mandrel 14 , as can be appreciated by those skilled in the art.
In summary, in some embodiments of the invention, the valve assembly 10 may be run downhole with the ball valve 22 in the open state, with a string 30 , including a shifting tool 16 , disposed through the ball valve 22 . The string 30 is used to conduct an operation (like gravel packing) below the ball valve 22 . When the operation is completed, the string 30 is pulled up and the shifting tool 16 engages the collet actuator 13 . Due to the presence of the index mechanism 20 , movement of the mandrel 14 is initially restricted. In order to move mandrel 14 to close the ball valve 22 , the shifting tool 16 must be used to move the collet actuator 13 up and down the predetermined number of times until the index mechanism 20 is disengaged. Once the index mechanism 20 is disengaged, the shifting tool 16 pulls the collet actuator 13 and mandrel 14 upward closing the ball valve 22 . The string 30 is then removed from the wellbore. By requiring the predetermined number of times, the index mechanism 20 prevents the inadvertent and/or premature closure of the ball valve 22 .
At this point, index mechanism 20 is disengaged (with index pin 292 always subsequently riding in groove 407 ) and the mandrel 14 can be forced down by the mandrel 12 . The operator may at this point wish to pressure test the tubing string above the ball valve 22 or perform other pressure-responsive operations. Due to the presence of index mechanism 15 , movement of the mandrel 12 is initially restricted. As such, the pressure cycles will not act to open the ball valve 22 until after the predetermined number of pressure cycles have been performed. After the last of the predetermined pressure cycles, the index mechanism 15 disengages, allowing mandrel 12 to move downward, act on collet actuator 13 , and move collet actuator 13 and mandrel 14 (since index mechanism 20 is also disengaged) to open ball valve 22 . Once both index mechanisms 15 , 20 are disengaged, the ball valve 22 may be opened or closed through the engagement between shifting tool 16 and collet actuator 13 . At this point, one shift down will normally open ball valve 22 , and one shift up will normally close ball valve 22 .
Although the use of the mandrel 12 and the predetermined number of pressurization/de-pressurization cycles are described above for opening the ball valve 22 after the pressure tests, the ball valve 22 may also be opened via the shifting tool 16 . In some embodiments of the invention, the index mechanisms 15 and 20 may be disengaged in a reverse order to that described above. In this manner, in some embodiments of the invention, the pressurization/de-pressurization cycles may be used to open and/or close the ball valve 22 before the shifting tool 16 is used in connection with the up and downstrokes of the collet actuator 13 . Other variations are possible.
Referring to FIG. 10, in some embodiments of the invention, the valve assembly 10 may be located inside a production tubing 600 . As shown, the valve assembly 10 is located closer to the surface of the well than a port closure sleeve 602 (of the production tubing 600 ) that is located downhole from the valve assembly 10 . For the vertical arrangement depicted in FIG. 10, the valve assembly 10 is located above, or uphole from, the sleeve 602 .
This relationship between the valve assembly 10 and sleeve 602 may be particularly advantageous for use with gravel packing operations. In this manner, the port closure sleeve 602 includes radial ports that may be opened for purposes of a gravel packing operation, an operation in which a gravel packing tool (not shown) may be extended through the valve assembly 10 and positioned near the port closure sleeve 602 so that gravel may be introduced around the exterior of the production tubing 600 . After the completion of the gravel packing operation, the gravel packing tool may then be withdrawn through the valve assembly 10 .
It is possible that the introduction of gravel through the radial ports of the sleeve 602 may compromise the seal integrity of sleeve 602 . For example, when the sleeve 602 is supposed to be closed to seal off the internal passageway of the production tubing 600 from receiving fluid from outside of the tubing 600 , debris that is introduced by the gravel packing operation may keep the sleeve 602 from forming a tight seal when closed.
However, because the valve assembly 10 is located between the sleeve 602 and the surface of the well, the valve assembly 10 may be closed to perfect the seal that may otherwise not be provided by the sleeve 602 . Thus, the location of the valve assembly 10 above the sleeve 602 circumvents potential sealing problems that may occur with the use of the sleeve 602 .
In the preceding description, directional terms, such as “upper,” “lower,” “vertical,” “horizontal,” etc., may have been used for reasons of convenience to describe the isolation valve and its associated components. However, such orientations are not needed to practice the invention, and thus, other orientations are possible in other embodiments of the invention.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention. | An assembly that is usable in a subterranean well includes a valve, a sleeve and an index mechanism. The valve is adapted to selectively isolate a region of the well, and the sleeve is adapted to be moved by a downhole tool to cause the valve to transition from a first state to a second state. The index mechanism prevents the valve from transitioning from the first state to the second state until after a position of the sleeve follows a predefined pattern. | 4 |
FIELD OF THE INVENTION
The present invention relates to improvements in an ignition distributor of an automotive vehicle delivering a high voltage from the coil to the proper spark plug in the firing order.
DESCRIPTION OF THE PRIOR ART
An ignition distributor of a vehicle generally has a plate secured to a housing of the distributor, through which the ignition apparatus is secured to the engine by means of screws or the like. By the way, such distributor generally has through-holes formed in the housing for ventilation through which fresh air is introduced into the inside of the housing and air containing ozone, nitrogen oxide or the like generated by the discharge therein is discharged outside the distributor housing therethrough in order to protect parts housed in the distributor against corrosion damage. However, if gassorine vapour which is inflammable enters the housing through the above-mentioned through-holes and catches fire by the discharge therein, such spark comes out of the housing through the holes.
To prevent such problem, much improvements have been done, but very few of them have been put into practical use costwise. One of good counter-measures for solving the problem was disclosed, for example, in a Japanese laid-open unexamined utility model application No. 52-93836 which comprises a plate secured to a body of a distributor, through which the ignition apparatus is secured to the engine by means of screws. The disclosed distributor further has a bore having its length in the axial direction in the body, one end of which opens into the housing room and the other end to the outside of the housing, wherein the other end opening portion and the above described plate are facing each other to form an air gap therebetween so that an unfavorable thing happened within the housing, which has been caused by the discharge, is prevented from coming outside of the housing through such bores.
However, the above described conventional type distributor in turn has a difficiency that because of the other side opening, adjacent to the plate all the time with narrow air gap therebetween, this may degrade the ventilation effect thereof.
SUMMARY OF THE INVENTION
Accordingly, in order to throughly solve the problems of the prior art, as described herein, an object of the present invention is to provide certain improvements in the construction of and the ventilation effect of the ignition distributor which is adapted to be easily manufactured to suppress or substantially eliminate unwelcome influence to parts mounted near the distributor through the ventilation holes, which is caused by the discharge, as well as to provide good ventilation effects within the housing.
This object is accomplished by having a plurality of through-holes provided in the housing, each of which communicates the outside of the housing with its inside, and by also having a member mounted onto a rotary shaft disposed within the housing and they are arranged so that such through-holes are substantially closed with the member when a discharge electrode and each side electrode are facing each other by rotation of the shaft driven from the engine camshaft. There be made communication passages between the outside of the housing and its inside when the discharge electrode and each side electrode are not facing each other. Therefore, even when any unfavorable thing happened within the housing, which has caused by the discharge, it can be prevented from reaching outside the housing through the holes when the discharge electrode comes close to each side electrode, on the other hand, good ventilation effects between the outside of the housing and its inside are gained via the holes during a time that the discharge does not occur.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments when considered in conjunction with the accompanying drawings:
FIG. 1 is a sectional view of a first embodiment of an ignition distributor according to the present invention;
FIG. 2 is a plan view taken on line A--A of FIG. 1;
FIG. 3 is a perspective view of a governer plate of the first embodiment;
FIG. 4 is a sectional view of a second embodiment;
FIG. 5 is a perspective view of the plate of the second embodiment;
FIG. 6 is other embodiment of the plate used in the second embodiment;
FIG. 7 is a sectional view of a third embodiment;
FIG. 8 is a perspective view of a plate used, with the third embodiment of the invention, in association with another plate which is slightly modified from FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 to 3, 3 designates a distributor housing having a bearing 2 which supports for rotation an engine driven shaft 1. First and second through-holes 4 and 5 are provided at the side of and the bottom of the housing 3 respectively. 6 designates a disc type governer plate mounted onto the shaft 1, which includes a pin 7. Flyweights 8 having pins 9 are rotatably supported to the governer plate 6. A governer advance adjusting mechanism consists of the governer plate 6, the pin 7, the fly-weights 8, the pin 9, cam plates 10, springs 11 and pins 12. The flyweights 8 and the cam plates 10 are retained by the springs 11. A signal rotor 13 is secured to a tube member 24 drivingly connected with the shaft 1 by the governer advance adjusting mechanism capable of changing the angular relation between the shaft 1 and the signal rotor 13. A bracket 15 including coil windings 14 is disposed in position shown in FIG. 1 so that it faces the signal rotor 13 and is supported within the housing 3 by a magnet 16 and a supporting member 17. A distributor cap 18 is held upon the housing 3 by appropriate means such as a clamp spring or the like. 19 designates a center electrode to which coil secondary high voltage output is fed and which is electrically connected with a spark gap electrode 20 by a spring 22 supported by the housing 3. The spark gap electrode 20 is fixed and secured to a body or rotor 21 supported by the tube member 24 drivingly connected with the shaft 1. Distributor cap electrodes or side electrodes 23 are provided in the distributor cap 18 and are disposed such that they, four side electrodes 23 in the embodiment, are spaced equally round the periphery of the cap 18 and their extended tip portions 23a come close to the spark gap electrode 20 as the rotor 21 turns. The governer plate 6, as shown in FIG. 3, includes four axial integral flanges 6a equally spaced on its circumference, which face the inside wall of the housing 3 to form a narrow air gap therebetween. As shown in FIG. 1, the first through-hole 4 is substantially closed with one of the flanges 6a when the spark gap electrode 20 becomes close to each extended tip portion 23a of the side electrodes 23, therefore, the flanges 6a have, in the longitudinal direction, length longer enough to cover the opening portion of the first through-hole 4 during a time that the spark gap electrode 20 and the side electrodes 23 are facing each other while the second through-hole 5 being substantially covered with the bottom side surfaces of the governer plate 6.
In operation, the shaft 1 rotates as the engine speed increases. As the distributor shaft 1 rotates faster, the flyweights 8 swing outward against spring pressure of the springs 11 while advancing or moving the cam plates 10 forward in the direction of rotation in relation to the distributor shaft position. At this time, the tube member 24 is also advanced in time in the rotational direction. An electrical signal generated for every passing of projections 13a of the signal rotor 13 across the bracket 15 functions as accurately breaking or interrupting the coil primary current flowing through a primary winding of an ignition coil. And, the secondary high voltage output in response to an ignition timing being generated, it is fed to the center electrode 19 and flows through the center electrode 19 to the spark plugs in the correct order to match the engine firing order, via the spring 22, the spark gap electrode 20 and the side electrodes 23.
When the spark gap electrode 20 comes close to the side electrodes 23 the discharge occurs. Even if any unfavorable thing accidentally happened within the distributor housing 3, which has been caused by the discharge, at this time, the first and second through-holes 4 and 5 are substantially covered by the proper flange 6a of and the bottom side surfaces of the governer plate 6 respectively whereby such unfavorable thing can be prevented from reaching outside the distributor through the through-holes 4 and 5.
On the other hand, when the spark gap electrode 20 and the side electrodes 23 are not facing each other, the flange 6 is positioned to make air passages for ventilation between the first and second holes 4 and 5 through cut portions 6b. Rotational motion of the governer plate 6 and the cam plate 10 causes air to flow into and out of the distributor through the holes 4 and 5, the ventilation effects are, thus, much more improved and as the flange portions 6a for intermittently shuttering the air passages with respect to the discharge timing are formed into an integrated body with the existing governer plate whereby there is no necessary to provide additional parts for such purposes, then, the number of parts can be reduced.
In the above-described first embodiment, the governer plate 6 has a double function. However, as shown in FIGS. 4 and 6, a second embodiment, a plate 25 having integral general axial tongues 25b is secured to the governer plate 6 by the pins 9 pressed into holes 25d in the plate 25 and secured by means of crimping or the like. The plate 25, hereupon, has flat surface portions 25a and the tongues 25b as shown in FIG. 5 so that when the spark gap electrode 20 comes close to the side electrodes 23, at this time, too, the first and second through-holes 4 and 5 are substantially closed by the proper tongue 25b of-and the flat surfaces 25a of the plate 25 both adjacent to the inboard openings of the through-holes 4 and 5 respectively, whereby, as in the same manner shown in the first embodiment described above, any unfavorable thing accidentally happened in the distributor housing 3, which triggered by the discharge action, can be prevented from reaching outside the distributor housing 3. On the other hand, when the spark gap electrode 20 and the side electrodes 23 are not facing each other, or when the discharge does not occur, the plate 25 is positioned to make for ventilation air passages between the both through-holes 4 and 5 through cut portions 25c, then, a sufficient air goes in and out of the distributor housing 3.
In stead of using the plate 25, a cup-like stamping 26 of FIG. 6 can substitute in this second embodiment, in which substantially rectangular tabs 26b are stamped from a body portion 26d, projecting outwardly from the body portion 26d at position shown in FIG. 6, to function as fan blades when the stamping 26 is driven in rotation by means of the shaft 1, a sufficient amount of air flows from the second through-hole 5 to the first through-hole 4 through slots 26c and spaces between flanges 26a. Accordingly, when the spark gap electrode 20 comes close to each of the extended tip portions 23a of the side electrodes 23, as in the same manner described heretofore, an unfavorable thing accidentally happened in the distributor housing 3, which triggered by the discharge action, can be prevented by the flange portions 26a from reaching outside of the distributor via the through-holes 4 and 5.
In the above-described first and second embodiments, the first through-hole 4 is provided at a relatively lower side portion of the housing 3, but, in a third embodiment shown hereupon, the first through-hole 4 is provided at position shown in FIG. 7, a relatively upper portion in the housing 3 in the third embodiment, wherein a first plate 27 which is modified from the stamping 26 of FIG. 6 to have slots 27c and the substantially rectangular tabs 27b projecting in the same direction as the flanges 27a project, is used and into a center slot of which the tube member 24 is press-fitted. A second plate 28 of FIG. 8 including a body surface portion 28a and slots 28c is additionally used for alternately opening and closing air passages between the first and second through-holes 4 and 5 through spaced portions 28b. The second plate 28 is secured to the bottom side of the governer plate 6 by means of the pins 9 press-fitted into the slots 28c. Operation of the third embodiment will not be described as it is the same as those cases described above. In this third embodiment, the first plate 27 is secured by press-fitting to the tube member 24 at position above the governer advance adjusting mechanism so that the first plate 27 is not under the advance effects of such advance adjusting mechanism, thus causing a precision position control of flanges 27a to position of the first through-hole 4 in relation to the exact discharge timing. Consequently, length of the longitudinal direction of the flanges 27a can be reduced. Reducing length of the flanges 27a will in turn cause enlarged spaces between the flanges 27a, thereby to effect a good circulation of air in the housing 3.
In the first to third embodiments so far described above, the flanges or tongues 6a, 25b and 26a, and space portions therebetween are respectively formed by dividing its circumference equally into equal parts, however, it, of course, may be possible to decide the length of those flanges in the rotational direction for good air circulation thereof in consideration of the governer advance angle, the negative pressure advance angle and the like. In addition, the members 6, 25, 26, 27 and 28 are all disc type, but they may be modified into columnar members respectively. Further, it may also be possible to provide such through-holes in the distributor cap 18. The embodiments have been referred to an ignition distributor in the case of four-cylinder, four-cycle automotive engine, however, same effects may be achieved if the present invention is applied to other type of engines.
In the afore-going embodiments thus far constructed, it will be apparent that the member secured to the distributor shaft can substantially opens and closes the through-holes communicating between the inside of and the outside of the distributor housing in relation to the exact discharge timing, whereby the ignition distributor of the present invention has a great advantage such that an unfavorable thing accidentally happened within the distributor housing, which triggered by the discharge action, can be prevented from reaching through such through-holes to the outside of the distributor housing and that a sufficient amount of air flow therethrough can be effected in the event the discharge does not occur. | An ignition distributor for internal combustion engines that improves ventilation efficiency, particularly when a rotor electrode does not come close to counterelectrodes, and that protects against the effect of an unfavorable thing to the outside of the distributor, which triggered by the discharge action. A closure member is provided that is mounted on to the distributor shaft and is in position adjacent to the inboard openings of ventilating holes formed in the housing which communicate the inside of the housing with its outside for ventilation. The member controls the communication therebetween for substantially restricting the communication when the discharge occurs in the housing and opening it when the discharge does not occur. The opening and closing of the communication is alternately repeated in response to the exact ignition discharge timing. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a miniature direct current rotary electric machine.
2. Description of the Prior Art
In order to improve the efficiency of a miniature direct current rotary machine it has been proposed to use a coreless rotor therein. As such coreless rotor there have been already known and used various rotors in a form of drug-cup. Since the rotor is consituted of a coil having no iron core therein, it has many advantages that there is produced no hysteresis loss by alternate changes of magnetic flux; eddy-current loss at the side of stator is small and as a whole there is no need of worrying about iron loss or core loss.
On the other hand, however, these types of known rotary machines involve some problems in forming the coils in particular when they should be designed to satisfy specific requirements such as revolution number suitable for specific applications thereof.
For example, according to one of the known methods of winding coreless rotary coils, a plurality of curved rectangular coil elements are disposed on a rotary shaft with their centers being aligned with the center of the rotary shaft so as to form a cylindrical body. These elements assembled into a cylinder in this manner are then fixed together by a suitable bonding material such as synthetic resin applied to the circumference of the formed cylindrical body which gives a rotary coil body. This rotary coil body is relatively large in coil thickness in the direction normal to the length of the rotary shaft. Because of the large thickness, there is caused a shortage of gap magnetic flux density which produces a problem of coarse revolution.
According to another known winding method, inclined coil elements wound on a cylinder are assembled into a cylindrical body by connecting the elements at their both ends successively from field pole to field pole without any end connnection wire part between adjacent windings. The coil elements thus assembled into a cylindrical body are then fixed together by a suitable bonding material such as synthetic resin to form a rotary coil body. This coil body has a relatively small coil thickness in the direction normal to the length of the rotary shaft. However, when the coil body is desired to have a short axial length to give a flattened shape of coil, there arises a problem. The problem is that the breadth of windings, that is, the number of active conductors, is severely limited with the decrease of the angle of inclination of the active coil interlinking with magnetic flux.
To solve the above problems involved in the first and second winding systems according to the prior art, we have already proposed an improved type of coreless rotary coil body in a form of cup. The coil body comprises a coil part inclined with a predetermined angle of inclination on the circumference of the coil body and an end connection part disposed to make a connection between adjacent windings of the coil part only at one side end of the inclined coil part. This system of winding enables one to improve the rate of winding and increase the number of active conductors while reducing the resistance of winding (armature resistance). This improvement is the subject of a prior application filed by the assignor of the present invention and published as Japanese Patent Application Publication No. 22361/1974.
In designing a coreless type of direct current motor with a cup-shaped rotary armature it is essential to suitably select the direct current resistance R, the number of active conductors Z and the active magnetic flux Φ for the armature whose field system is a permanent magnet. As well known in the art, iron loss (core loss), copper loss (ohmic loss) and mechanical loss constitute three important losses in direct current motors. If the rotor is formed as a coreless one, then the hysteresis loss caused by the alternate change of magnetic flux is eliminated and also the eddy-current loss occurring at the side of the stator becomes negligibly small. It is no longer necessary, as a whole, to take the iron loss into account. Furthermore, by using a coreless structure, the reactance voltage usually generated in the coil at the time of commutation can be reduced to the lowest level and therefore nearly ideal commutation is attainable which gives the commutating mechanism an improved stability and an extended useful life.
For the above mentioned type of motors, the following pure equation of motor circuit in which no iron loss is taken into consideration holds well:
IaV-Ia.sup.2 R=IaEc . . . (1)
wherein,
V=terminal input voltage,
Ia=armature current,
Ec=back electromotive voltage and
R=Ra+Rb in which
Ra=armature resistance and
Rb=brush contact resistance.
Therefore, a larger output IaEc can be obtained by reducing the ohmic loss Ia 2 R to a smaller value relative to the input IaV. This means that a motor of very high efficiency can be made by a proper control of the mechanical loss contained in IaEc.
However, there are some applications of motor for which the motor has to be designed to satisfy particular requirements regarding revolution number and other properties. In such case, a particular technique is required by which the actual values of R, Z and Φ can be determined most suitably for the aimed purpose.
Techniques for forming a cylindrical, cup-shaped coil without any end connection at its both ends are disclosed, for example, in Japanese Patent Application Publication No. 2151/1963, U.S. Pat. No. 3,360,668 and DAS No. 1,188,709. One example of such cup-shaped coil is shown in FIG. 2. There may be the case wherein a coil in a form of flattened cup as shown in FIG. 1 should be designed employing the technique used for the coil of FIG. 2 which has a larger axial length than that in FIG. 1. However, the use of the known technique as mentioned above for making such a flat cup-shaped coil as shown in FIG. 1 has some difficulty. The inclination θ of the active coil interlinking with the magnetic flux in FIG. 1 is smaller than that in FIG. 2. As shown in FIG. 3, when the inclination θ is small, a limitation is put on the width of coil segment So' by which the number of active conductors is determined. The limitation is sharply enhanced with the reduction of the inclination θ.
In FIG. 3, the symbol So is a quotient given by dividing the length of circumference of the rotor by the number of commutator segments. Therefore, So means coil width per segment and the number of windings which can be wound within the width of So corresponds to the number of coils which can be wound in one slot on an iron core. Even when coils have the same width of So, the width So' within which the coil can be really wound may be different from each other. Since SO'=So·sin θ, the width So' varies depending upon the inclination of coil θ. Of course, θ must be constant for one coil. If it varies from one place to another in one and same coil, So' will be limited by the smallest inclination θ in the coil. In this sense, the locus of coil turn must describe a spiral with a constant inclination on the cylindrical surface of the armature. To receive the effective number of conductors in the width So', the diameter of wire to be wound is decreased with the decrease of the axial length (cup depth) for the same diameter dm of armature. Thereby, the armature resistance Ra in the above equation (1) is increased and therefore the ohmic loss is increased which reduces the efficiency of the motor.
FIG.4 shows one example of a coil disclosed in the above mentioned our prior application Japanese Patent Application Publication No. 22361/1974. As the coil body has an end connection part provided only at its one side, the inclination of coil winding wound on a cylindrical surface, that is, the angle θ can be selected at will. When the axial length of the cup-shaped coil is reduced, the inclination θ of the active coil winding part is not reduced in proportion to the reduction of axial length but is set to an optimum value obtained by a calculation of the three important factors, armature resistance Ra, number of active conductors Z and total active magnetic flux Φ. Therefore, the severe limitation concerning the width So' described above can be moderated to prevent the increase of armature resistance Ra when a flat cup-shaped coil is used.
When the flat cup-shaped coil shown in FIG. 1 is compared with that shown in FIG. 4 in respect to the resistance Ra, it is found that Ra for the former is 2.23 Ω and that for the latter is 0.66Ω provided that for both the coils, dm (average diameter)=29.4 mm, lc(coil height)=18 mm, tthe number of commutator segments=5 and the number of active conductors Z=240 lines.
In case of the cup-shaped coil body shown in FIG. 4 for which the above calculation was made, the turn-back points A and C are set at the positions of πdm/2, that is, the positions opposed to each other at 180° and the segment AC of winding extends along the upper edge of the cup. But, this can be modified as shown in FIG. 5. In the modification shown in FIG. 5, the segment AC of the winding extends straightly or almost straightly to form a chord of the circular upper edge of the cup serving as an end connection part. Employing the modification of FIG. 5, a further reduction of the resistance Ra can be attained without any reduction of the effective values of Z and Φ. To demonstrate this, ABCA=10.4 cm and Ra=0.66Ω for the FIG. 4 example are compared with the data ABCA=9.2 cm and Ra=0.59Ω for the FIG. 5 example. Compared with the conventional cup-shaped coil body shown in FIG. 1, the armature resistance Ra is reduced to 1/4.
As shown in the above, the invention of Japanese Patent Application Publication No. 22361/1974 was directed primarily to analyze R and Z of the three important factors. A further development of the invention has led us to the finding that the area of the coil intersecting the magnetic flux can be increased or decreased as desired by suitably selecting the positions of end connection. This finding has been disclosed in detail in German laying-upon print DT-OS No. 2,126,199. Namely, it has been found that the turn-back points A and C mentioned above are not always necessay to lie on the diameter of the cup, that is, at such positions corresponding to πdm/2, but the inclination θ can be decreased or increased according to the extent to which the cup should be flattened.
In the above calculation of armature resistance Ra, such case was shown in which the end connection positions lie on the dimeter of the cup (FIG. 5). The end connection positions may be shifted as seen in FIG. 8. In FIG. 8, if the position of x is displaced in the negative direction relative to X--X' axis, one can find out such position in which the area of coil becomes maximum as later shown by a numerical calculation. On the contrary, if the position x is displaced in the direction of the positive side of the X--X' axis, then the winding rate will be further improved although the area of coil will be decreased.
The following description explains the manner of how to find out the position in which the area of coil is maximum:
It is known that the quantity of any one axis component of moment generated in a closed circuit, when the closed circuit formed by any closed curve is placed in a parallel magnetic field, is in proportion to the area of orthogonal projection of the closed circuit on a plane extending parallel with the axis and the direction of the magnetic field. FIG. 6 shows the relation between the orthogonal projection coil area and the position of the end connection for a coil as shown in FIGS. 5 and 8. The central angle α to the end connection length AC is referred to as end connection angle which may be either α (narrow angle) or 2π-α (wide angle). In this case, the area of coil given as follows:
As curve L is a spiral line, let k denote the tangent to the inclination of the spiral L. γ is the angle shown in FIG. 6 which indicates the position of winding by an angular coordinate of cylindrical coordinate system. Then,
z=rγk . . . (1)
and
y=r sin γ=r sin (z/rk) . . . (2).
Formula (2) indicates that the orthogonal projection of spiral (L) is a sine curve. Torque T(t) generated in one coil winding is given as follows by a numerical calculation through many transformations of the formula not shown:
T(t) max=1.45 rlBI . . . (3)
wherein, B is gap magnetic flux density in gauss and I is electric current in ampere. In the shown case, α=92.92°˜92.94°≈93°.
Since the case shown in FIG. 7 corresponds to such case in which t=1 in FIG. 6, there is given:
T(1)=1.27 rlBI . . . (4)
Let t=1/2 (end connection lies on the diameter of the cup), then,
I(1/2)=1.27 rlBI . . . (5) .
Thus, the area of coil obtained is the same for the two cases. But, since θ is larger in case (5) than in case (4), it is seen that the case (5) is more advantageous than the case (4) with respect to winding rate.
In summary, it may be said that for a cup-shaped armature coil there is obtained a freedom in selection of the values of R, Z and Φ by providing an end connection at one side end, without any loss of structural functions as a cup-shaped rotor. However, practice, this can be realized only when there is established a useful method by which a conductor wire can be wound in many turns orderly and prefectly in accordance with the above principle. Otherwise, it is impossible to wind a given number of wires having a given wire diameter into a coil of predetermined thickness. Especially, there may often occur such trouble that the crossed parts of wires are crushed by the pressing pressure applied to the parts at the coil thickness shaping step after winding and thereby a rare short is caused.
FIG. 9 is a typical characteristic curve of a direct current motor having a field system of magnet. In FIG. 9, the abscissa is torque T and the ordinate is current I for curve 1 and revolution number N for curve 2. Let K denote the torque constant and m the revolution number separation characteristic constant which is a reciprocal of ratio of the change Δn of revolution number N to a torque change ΔT, then,
K=ΔT/ΔI and m=ΔT/Δn
wherein, ΔI is change of current I for a certain change of torque ΔT.
As to the constant m, it is also known that it is in proportion to the square of K and is in reciprocal proportion to the resistance R between motor terminals (m˜K 2 /R). Therefore, if applied voltage V becomes known, all the factors such as torque required for the motor, its revolution number N, driving current I, suspension constant m and starting torque can be determined by the values of torque constant K and resistant R.
Regarding the torque constant K, it is also known that it is in proportion to the product of number of active conductors Z multiplied by total active magnetic flux Φ (K˜ZΦ). This means that it is essential to properly select the values of Z and Φ in designing a motor for obtaining the desired output of revolution torque. On the other hand, in order to minimize the production cost of the motor, it is required to use an inexpensive magnet such as that of barium-ferrite system instead of an expensive alnico magnet as the field magnet in the motor. To satisfy the requirement concerning the production cost, it is inevitable that Φ becomes small. This reduction in Φ must be compensated by increasing Z, the active conductor lines per segment. In this case, to maintain a certain necessary value of m it is required to satisfy the condition that the resistance R should not be increased with the increase of Z. This condition necessitates the use of such conductor wire which is low in resistance per unit length (wire of larger diameter).
For a cup-shaped coreless revolving coil, a certain number of conductors having a certain wire diameter as given by the above calculation are wound up on a cylindrical coil body in two or more layers to form a cup coil having a desired coil thickness t. However, note should be taken or the fact that a regular relation as shown in FIG. 10 is not always established between the wire diameter d used and the coil thickness t and, instead, it is often required to wind up conductor wire in an indefinite number of layers as shown in FIG. 11. In other words, according to the prior art, the coil thickness t is limited only to an integral multiple of the diameter d of wire used at that time, which is usually twice. There has not yet been known any method which enables to form a coil with any desired coil thickness independently of the wire diameter.
Among many coil winding methods hitherto known for the above mentioned type of coreless resolving coil, the method disclosed in the Japanese Patent Application Publication No. 22361/1974 is featured in that adjacent windings are conneced with each other only at the one side end of the inclined coil part wound on the coil body as shown in FIG. 5. As clearly shown in FIG. 5, every element coil is wound in such manner that the elements form the opening of a cup of their lower ends and they are turned back at the opening toward the upper edge of the cup along the cylindrical surface of the cup. At the upper edge, adjacent windings are connected with each other successively at the end connection part.
SUMMARY OF THE INVENTION
It is an object of the present invention to further improve the winding in the coreless revolving coil disclosed in the above mentioned prior art of Japanese Patent Application Publication No. 22361/1974.
It is another object of the invention to provide a novel structure of miniature rotary electric machine in which the improved winding is used.
It is a further object of the invention to provide a winding for a motor and a motor provided with the same which is higher in efficiency than those designed according to the prior art.
Other and further objects, features and advantages of the invention will appear more fully from the following description of embodiments with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 schematically show examples of cup-shaped coil formed according to the prior art,
FIG. 3 is an expanded view of the coil shown in FIG. 1,
FIGS. 4 and 5 are schematic views similar to FIGS. 1 and 2 but showing the manner of coil winding according to the prior art disclosed in Japanese Patent Application Publication No. 22361/1974,
FIG. 6 shows the relation between coil orthogonal projection area and an end connection for the FIG. 5 coil,
FIGS. 7 and 8 show the manner of coil winding on the coil shown in FIG. 5,
FIG. 9 is a characteristic curve of a motor having a magnet field system,
FIG. 10 is a sectional enlarged view of a coil in layers, the number of layers being an integral multiple of wire diameter,
FIG. 11 is a view similar to FIG. 10 but showing another coi in an indefinite number of layers,
FIG. 12 schematically shows the manner of winding in a coil according to the present invention,
FIG. 13 shows the end connection part between adjacent windings in a coil formed according to the present invention, especially lead wire portion of the end connection part leading to commutator segments,
FIG. 14 is a perspective view of an embodiment of a coil according to the present invention showing the manner of winding used therefor,
FIG. 15A is a plan view of the coil body shown in FIG. 14, and
FIG. 15B is an expanded view of the same.
FIG. 16A is an axial sectional view of a coreless motor in which a coil formed according to the present invention is used,
FIG. 16B is an axial sectional view of the stator of the coreless motor shown in FIG. 16A, and
FIG. 16C is an axial sectional view of the rotor of the coreless motor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIGS. 12 and 13, an embodiment of the present invention is described. FIG. 12 illustrates the manner of winding of a coil element in a revolving coil according to the invention and FIG. 13 illustrates the manner of connection between two adjacent coil elements, together with a lead wire portion to a commutator segment. In FIG. 13, the reference numeral 1 designates a first conductor group and 2 is a second conductor group. Extending from the first conductor group to the second one is a transition part. The first group 1 comprises three coil windigs the starting end of which is indicated by 1a. Each of the three windings has an end connection part 1A 1 , an inclined winding part 1B 1 (going side), a turning-back part 1C 1 and an inclined part 1D 1 . In other words, a passage of conductor wire along the course of 1A 1 -1B 1 -1C 1 -1D 1 forms one winding and in the shown example, three such windings constitute the first conductor group. In each the conductor group, space 5 between lines is closed as a result of close contact of the lines with each other. Also, space 6 between two conductor groups 1 and 2 is closed in a manner of close contact at a processing step carried out after winding.
According to one embodiment of the present invention, a coreless revolving coil body is formed in the manner shown in FIG. 14.
In FIG. 14, the rotation axis of the coil body is indicated by o--o', its average diameter by dm, its length by l and angle of spiral winding is indicated to θ. As seen in the drawing, a wire has its start point at a position a on the cylindrical body and at first goes to a turning-back point Y 1 from the start point a spirally along the cylinder surface with spiral angle θ. After turning back at Y 1 , the wire goes also spirally along the cylinder surface at the backside up to a position a' lying on the outer circumferential edge of one end surface 8 of the body. From the point a' the wire further extends to a point b next to the start point a across the end surface 8 in such manner as to describe a chord a'-a. This winding of wire passing through the course of a-Y-a'-a is repeated many times as desired to form a first conductor group as shown in FIG. 13.
After the first conductor group 1 being formed, the second conductor group 2 is formed in a similar manner starting from a point close to the above mentioned start point a' and passing through again the end connection part 8. At the time of the second conductor group being formed, however, the direction of winding in which the wire extends from point a' to b' across the end connection part is shifted by a predetermined angle.
In FIG. 14, the end connection part of the first conductor group 1 is indicated by 1A and that of the second group 2 by 2A. 10a, 12a, 14a and 16a designate lead wire portions for segment connection. Inclined wire parts 1, 2, 18, . . . of the conductor groups as well as end connection wire parts 1A, 2A, . . . of the conductor groups are arranged in parallel to each other so as not to cross each other.
FIG. 15A is a plan view of the coil body shown in FIG. 14 and FIG. 15B is an expanded view of the same.
After windings have been formed all around the body, the inclined wire parts 1, 2, 18, . . . of all the groups are contacted closely with each other by a shaping processing to eliminate any space between winding lines and to form a uniform and complete coil body.
Now, the effects of the present invention are described comparing the winding according to the invention with the prior art one.
As previously described, when one wishes to make a motor having a desired motor characteristic at an applied voltage V, this may be attained by suitably selecting the values of torque constant K and resistance R. Since K˜ZΦ and Φ is constant for a given motor, K˜Z. This means that the desired motor characteristic is obtainable by suitably selecting Z under the condition of a suitable resistance R. It a coil is formed according to the prior art of the above mentioned Japanese Patent Application No. 22361/1974 by winding a wire of 0.3 mm in diameter at a rate of 50 turns per segment in a fashion of single row, close winding, then the width of winding space So' becomes 0.3×50=15 mm and the coil thickness is 0.6 mm (0.3×2=0.6). However, to reduce the revolution number of the motor, if a coil of 150 turns per segment is wished to be formed instead of that of 50 turns per segment, then it is required to use a smaller diameter of wire. Since the width of winding space So' is 15 mm, the wire diameter must be: 15÷150=0.1 mm. Accordingly, the coil thickness becomes 0.1×2=0.2 mm. Thus, the coil thickness is reduced from 0.6 to 0.2 although an increase of Z (active conductor lines per segment) up to 150 from 50 is attained. Since coil resistance is increased up at the inverse square of the wire diameter, the coil resistance for the latter mentioned 150 T (turns) coil becomes 27 times larger than the former as shown below.
Increase of resistance attributable to wire diameter: 3 2 =9 times
Increase of resistance attributable to wire length: 3 times (50T→150T)
Total increase of coil resistance: 9×3=27 times
On the other hand, the torque constant K in the latter case is 9 times larger than that in the former since Z becomes 3 times larger and 3 2 =9. Therefore, from m˜K 2 /R, the value of m becomes reduced to 9/27=1/3 compared with that in the former.
This remarkable decreases in m is caused by the fact that the winding space available for the given motor (coil thickness of 0.6 mm and winding width of 15 mm) can not be made full use of according to the prior art in the direction of thickness. Namely, while the winding width of 15 mm is used fully, the thickness used for the latter case is only 0.2 mm (1.1×2) which is mere one third of available thickness. If it were allowed to select such wire diameter with which man could obtain coil thickness of 0.6 mm after 150 turns and to wind such diameter of wire in plural layers as shown in FIG. 11, then the above decrease in m would be avoidable by employing a wire having a larger diameter at least larger than 0.1 mm. For example, if such wire having a diameter of 0.173 mm is used instead of the wire of 0.1 mm in diameter, the value of m is remained unchanged as compared with the former case of 0.3 mm diameter of wire since the resistance becomes 9 times larger than that in the former case, but at the same time the torque constant K becomes also 9 times larger.
According to the present invention, as described above, it is allowed to form a coil having a thickness three times larger than the diameter of wire then used to the same motor for which a coil having a thickness two times larger than the diameter of wire is formed according to the prior art. Therefore, by using the winding technique of the present invention, a valuable improvement in performance of motor is attained and, therefore, a substantial increase of coil strength as a revolving coil is obtained. In the above described case, the reduction of m to 1/3 means that the curve (2) in FIG. 9 becomes very steep and the starting torque becomes reduced only to 1/3 for the same no-load revolution number. The present invention eliminates such problem.
In general, the possibility that motor constant K may be made larger in designing a motor brings forth various advantages in addition to the improvement of m. For example, improvement of controllability, reduction of motor rising time constant and saving of electric power are also attainable. The constant K can be made larger, as described above, by increasing the value of Z. In increasing it is a key point that one holds down the increasing rate of R to a level lower than the increasing rate of Z. The present invention hits just this key point.
FIG. 16A shows a coreless motor in which the present invention is embodied.
The coreless motor comprises the following three structural components as its main parts:
(1) stator serving also as a motor casing;
(2) motor rotor; and
(3) motor cover means.
FIG. 16B is an axial sectional view of the stator part.
Designated by 20 is a motor casing which is made of soft magnetic material and in a shape of cylinder. At its one end 20a, the cylindrical casing 20 is open and the other end 20b is provided with an opening 20c through which a rotary shaft 24 is led out.
20d is a connecting part for connecting a motor cover with the casing. A description of the motor cover is made hereinafter. The connecting part is in a form of slot or hole formed on the circumference of the open end of the motor casing 20. Designated by 20f is an opening used for mounting the motor on an exterior part. 21 is a fixed field permanent magnet in a shape of cylinder whose inner circumferential surfaces 21a and 21b are covered by a fixing member 22 integrally formed with the permanent magnet 21 using synthetic resin material. The fixing member 22 has a flange 22a facing the side wall 20b of the casing and a bearing ball seat 22b formed to receive a self-aligning bearing 34. At the other end of the fixing member 22 there is formed also a bearing receiving portion 22e to receive a bearing 25. The fixing member 22 is fixed to the motor casing 20 through a member 23 as later described, with its end at the side of 22b abutting against the side wall 20b of the casing.
Designated by 23 is an auxiliary yoke for the stator. The auxiliary yoke 23 is inserted into the casing 20 to form a magnetic path together with the casing. The auxiliary yoke is in a shape of cylinder and its one end 23a abuts against a portion of the fixing member 22. The other end 23b of the yoke is engaged with and held by a projection 20e of the motor casing.
A portion 22c of the fixing member 22 projects into the magnet 21 so as to form a stopper against rotation.
FIG. 16C is a sectional view of the rotor. The rotary shaft 24 of the motor is received in the above described stator through bearings 25 and 34 for rotation. The rotary shaft has a knurled portion 24a on which a coil fixing member 33 is secured. The coil fixing member 33 is made of synthetic resin material. A cup-shaped coil 27 is fixed to the coil fixing member 33 at a portion of the inner circumference of the coil.
Designated by 29 is a commutator which is fixed onto an axial extension 33a of the coil fixing member 33 by moulding. One end of the commutator 29 is exposed to allow an electrical contact with a power supplying brush and the other end is connected to a power supply lead wire of the coil 27.
The manner of assembling the coreless motor shown in FIG. 16 is as follows:
A bearing metal (36 in FIG. 16A) is mounted on the stator already assembled in the manner shown in FIG. 16B and then the rotor shown for FIG. 16C is inserted thereinto.
Thus, the rotary shaft 24 is aligned with the permanent magnet 21 and supported rotatably through the bearings 25 and 34. In a space provided between the permanent magnet 21 and the yoke 23 there is inserted the coil 27.
From the right end side of the shaft 24, a spacer ring 38 and a stop ring 35 are pushed into along the shaft and then they are secured by a washer 40. The spacer ring 38 is used for size adjustment between the bearing 34 and the motor casing 20. The function of the stop ring 35 is to prevent bonding agent from flowing into the bearing when pulley or the like is bonded to the motor output shaft. A spring member 39 serves to urge the bearing 34 against the bearing ball seat 22b provided in the fixing member 22.
After inserting the rotor comprising rotary shaft 24, coil 27, commutator 29 and others into the stator, the opening of the motor casing 20 is closed by a cover member 32 as shown in FIG. 16A and the cover member is secured to the casing. The cover member 32 is made of synthetic resin material or metal material and has a power supplying terminal 30 fixed to the inside of the cover. The terminal 30 is led out outside of the casing so as to allow its connection to an external power source. At the other end, the power supplying terminal is connected to the above mentioned brush 31 which is, in turn, in contact with the commutator 29.
The cover member 32 fixedly holding the terminal 30 and brush 31 closes the opening of the motor casing 20 and the projection 32a of the cover member is fitted into the slot or hole 20a of the casing for fixing.
With the above described structure of coreless motor, the thickness of returning magnetic path is defined by the motor transfer 20 and the auxilary yoke 23. This structure of stator has an advantage that when it is wished to increase the thickness of coil 27, such change can be carried out very easily only by altering the thickness of the auxiliary yoke 23. It is unnecessary to change the motor structure as a whole. This structural advantage is also applicable when the material of permanent magnet 21 has to be changed.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in details can be made therein without departing from the spirit and scope of the invention. | The present invention relates to a miniature rotary electric machine and more particularly to a coreless type of rotary electric machine. The coreless rotary electric machine includes a rotor coil formed as a coil body in a form of cup with its one end being open. The coil body has, on its circumference, a coil part wound with a predetermined inclination. An end connection wire part is provided to make a connection between adjacent windings only at the one side end of the inclined coil part so that each two adjacent windings of the inclined coil part are connected each other successively by the end connection wire part. According to a feature of the present invention, the inclined coil part and the end connection wire part are formed by coil assembly portions each comprising a plural number of groups of windings turned at the same position in layers with the same number of turns. The coil assembly portions form together a coil assembly of large winding capacity. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates to a shaver unit for an electric shaver according to the generic part of claim 1 . Shaving units of this kind are designated to be used in electric shavers, beard trimmers and hair cutters. They can be arranged as a sole cutting element or in combination with other cutting elements—often they are used as so-called center trimmers and arranged between two shaving foils.
BACKGROUND OF THE INVENTION
[0002] Shaving units of the type initially referred to are known for example from EP 0693988 B1. This document discloses an electric dry shaver where a center trimmer is arranged between two foil type shaving elements. The upper cutter of this center trimmer is provided with hair feeding means consisting of projecting teeth which are directed outwardly. Those center trimmers in general are rather effective in cutting the hairs to a very short remaining length of hair. With respect to hairs which are resting flat against the skin the performance of the known cutting system is not optimal since such hairs—especially if they are located on skin areas with flexible skin—tend to escape from the feeding area formed between two teeth of the comb-shaped feeding means.
[0003] From the EP 1930135 A1 there is known a shaving head with a center trimmer which comprises a multiplicity of bars arranged at a small distance to each other, so as to form small slits between the bars. Such kinds of center trimmers are a more open construction without a center bar arranged along the longitudinal axis of the trimmer. Cutting units of this type have proven to be mechanically stable even with a small thickness of the outer cutter. The drawback of this kind of shaving units is the risk to cause skin irritations.
SUMMARY OF THE INVENTION
[0004] It is an objective of the present invention to provide an improved shaving unit for electric shavers of the type initially referred to such to ensure an optimal feeding of hairs as well as to avoid skin irritation during the shave.
[0005] This objective is accomplished by the combination of features as indicated in claim 1 .
[0006] According to the invention, the outer cutter provides two comb elements each directed inwardly. This inventive solution enables a high mechanical stability in combination with providing extremely thin comb elements, which consequently ensure an optimal lifting of hairs that are lying flat to the skin. A thin outer cutter additionally enhances a close shave because the cutting area between the inner and the outer cutter can be placed extremely narrow to the skin. The central area of the upper cutter between the inwardly directed teeth of the comb elements provides a high likelihood for hairs to be lifted from the skin.
[0007] In an embodiment of the present invention increasing the probability of catching as well as lifting hairs, the teeth of the first comb element are arranged offset in relation to the teeth of the second comb element along a direction of the relative motion. In a particularly advantageous embodiment of the invention the pitch of the teeth of the two comb elements is equal and the teeth of the first comb element are provided offset in relation to the second comb element by half of the pitch. This enables a longer free distance in front of the tips and helps feeding the hairs to be cut.
[0008] Another embodiment of the invention that helps both to completely avoid skin irritation during and after shaving and to capture flat hairs is characterized in that the teeth of the first and of the second comb element are designed such that their surfaces which contact the skin during the shaver lie in one plane. Another embodiment that is characterized by a superior performance of feeding hairs resting flat against the skin may be realized in a way that the teeth of the first and second comb elements each lie in planes that extend at an angle of 180-120 degrees to each other. Especially a difference in height of up to a maximum of 250 μm between the tips of the teeth and the respective opposite ends of the teeth—which means that the tips are upwardly elevated—is an optimal compromise which guarantees both extremely effective feeding performance with respect to hairs which are lying flat to the skin and avoidance of irritation of the skin. This is because during the shaving strokes this geometry leads to a deformation of the skin also in that range of 250 μm. This, in turn, makes it highly likely for the prong-shaped teeth to under slide and to then lift stubbles of a length of some 100 μm.
[0009] It has turned out that a distance between facing teeth tips of approximately 0.7 to 1.6 millimeters assures high shaving comfort as well as excellent feeding of hairs, even in case of a beard having grown for several days.
[0010] During a continuous shaving stroke the skin remains tensioned and stretched in the area of the gap between the facing teeth tips. However, when reversing the direction of the stroke the skin tends to penetrate into the gap due to the fact that skin folds may occur caused by peaks of the contact pressure between skin and shaver. Therefore, it is advantageous that the inner cutter is provided with a recess in its area between the tips of the teeth of the outer cutter. It is additionally beneficial to avoid sharp edges on the inner cutter in said area.
[0011] The inventive shaving unit may be incorporated in both linear/translational oscillating and rotatory shaving systems. This means that the relative motion of the inner and outer cutter may be a translational oscillating motion along the longitudinal axis of the shaving unit or a rotatory motion around the perpendicular axis of an annular-shaped shaving unit.
[0012] If at least one of the two comb elements is provided with a bar arranged opposite the tips of the teeth, the possibility of catching skin in a slit between two teeth is drastically reduced. Furthermore, if a hair lying flat, i.e. nearly parallel to the skin is fed between two teeth and then during the shaving stroke is pressed with its free end against this bar, there is a certain likelihood of leveraging the hair away from the skin and moving it deeper into the shaving unit to cut it.
[0013] The invention also concerns a shaving head whereby at least one shaving unit as described above is arranged, especially in combination with additional shaving units of the same type or of other types.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will be further elucidated by detailed explanation of exemplary embodiments and by reference to figures. In the figures
[0015] FIG. 1 is a perspective illustration of an exemplary embodiment of the invention,
[0016] FIG. 2 shows detail D 1 of FIG. 1 in a larger scale,
[0017] FIG. 3 is another perspective illustration of an embodiment of the invention,
[0018] FIG. 4 shows a cross-section along the longitudinal axis of a shaving unit according to FIG. 3 ,
[0019] FIG. 5 is a cross-section along the lateral axis through an embodiment of the invention according to FIG. 2 ,
[0020] FIG. 6 depicts Detail D 2 of FIG. 5 in a larger scale with omission of some details which are not important for the invention,
[0021] FIG. 7 shows an upper cutter according to the invention to be used in shavers of the rotating type and
[0022] FIG. 8 is a cross-section through the embodiment according to FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 shows an embodiment of a shaving unit 1 according to the invention, having a longitudinal axis X, a lateral axis Y and vertical axis Z. In the enlarged view, as depicted in FIG. 2 , there is shown the outer cutter 5 which consists essentially of the first comb element 2 , the second comb element 3 and the sidewalls 4 which parts all together compose the U-shaped form of the outer cutter 5 . In the embodiment according to FIG. 2 , the two comb elements 2 and 3 are arranged in a way that they run towards each other at an angle, whereby top faces of the comb elements which contact the skin during shaving increase in height from their outer borders 8 going inwards to shape a roof-form with an elevated middle part. For identical parts or parts which accord each other the same reference numbers are used in the description.
[0024] As can be taken best from FIGS. 1-3 , the two comb elements 2 , 3 are integrally formed and comprise a multiplicity of teeth 6 arranged at regular intervals. The respective pitch P is 0.9 mm. The teeth 6 extend inwardly in parallel to the lateral axis Y and have a length of 1.2 mm measured from the tooth root surface 9 to the tip 10 . The distance from the outer border 8 to the tip 10 is 2.25 mm. Every tooth has a width W measured along the longitudinal axis X of around 0.5 mm (500 μm) which—under calculating with the pitch P value of 0.9 mm—gives a value of the slit 7 between two teeth 6 of around 0.4 mm. The overall width of the shaving unit 1 (along lateral axis Y) is 5.5 mm and its length along the longitudinal axis X is 41 mm. The two end sections 11 of the shaving unit 1 which delimit the section where the teeth 6 are arranged have a plane surface without any tooth. The two end sections 11 may be provided with a relief-like structure for interacting with the user's skin or it may be perforated. The perforation of the end sections 11 positively impacts the process of bending the integrally formed two comb elements 2 , 3 along the common symmetry line 12 parallel to the longitudinal axis X. This bending is for providing an obtuse angle A between the two comb elements 2 , 3 . This topic and the advantages associated therewith will be described below, especially in connection with FIGS. 5 and 6 .
[0025] The outer cutter 5 encompasses the inner cutter 13 which also is U-shaped. It is composed of two side walls 14 which are interconnected by a plurality of bars 15 whereby the single bars are arranged displaced from each other by a distance to form a plurality of slots 16 between two adjacent bars 15 (see FIG. 4 ). The bars 15 are arranged at regular intervals. The respective pitch is 1.5 mm. The bars have a width along the longitudinal axis X of around 0.7 mm which leads to a slot width of 0.8 mm. A leave spring 17 is arranged preloaded between the inner and the outer cutter 13 , 5 to bias both parts against each other in a way that is known per se. The inner cutter 13 comprises coupling means 18 to be coupled in a known manner with an oscillating drive, which drive is not shown in the drawing. The outer cutter 5 is preferably fixed to a shaver head or a housing of an electric shaver, but might in a further embodiment of the invention (not shown) also be driven by a drive mechanism.
[0026] From FIG. 3 it can be taken that the first and second comb elements 2 , 3 are providing the same pitch P of 0.9 mm. However, the two comb elements are parallel shifted by 0.45 mm—which is half of that pitch—against each other. Consequently the tips 10 of the first comb element 2 are located opposite the slits 6 of the second comb element 3 .
[0027] FIGS. 5 and 6 are showing a cross-section along the lateral axis through an embodiment of the invention according to FIG. 2 and are clearly demonstrating the obtuse angle A between the two comb elements 2 and 3 . This angle A leads to a difference in height H between the outer border 8 and the tip 10 by an amount of 250 μm. The obtuse angle A between the two comb elements is produced by simply bending around the symmetry line 12 in the area of the end sections 11 . Consequently the teeth 6 of the comb elements 2 , 3 are brought into the angled position without getting touched by a bending tool.
[0028] The free gap G between the tips 10 of the first comb element 2 and their respective counterparts of the second comb element 3 is around 1.00 mm. The tooth length L—which is the distance from tip 10 to the tooth root surface 9 —is 1.2 mm. The height of the teeth in dimension Z is 150 μm in the area of the tips 10 and increases linearly along the length L in direction to the tooth root surface 9 up to 400 μm. Since the distance from the outer border 8 to the tip 10 is 2.25 mm, the conjunction bar 19 has width of 1.05 mm. By this, a bending stiffness of the teeth 6 is achieved which is optimally adapted to the teeth's capacity to cope with pressure. In this way, it will be possible to realize extremely thin comb tips 10 by nevertheless maintaining the stability of the teeth 6 . A tapering of the teeth 6 thickness towards the tips 10 is achieved by the removal of material at the underside of the teeth. It is true that there is an enhanced risk of skin irritations with extremely thin teeth, but the comb tips facing each other allow an optimal stretching of the skin, thus compensating for this risk.
[0029] The elevation of the tips 10 relative to the outer conjunction bars 19 causes a deformation of the skin in areas of flexible skin which helps lifting up flat lying hairs and directing them in a optimal alignment to then feed them into the cutting gaps defined by the slits 7 of the outer cutter 5 and the slots 16 of the inner cutter 13 . The teeth 6 are—as known per se—equipped with cutting edges 22 at their lower side and the bars 15 provide cutting edges 23 at their upper side.
[0030] To avoid skin contact with the driven inner cutter 13 in case the skin during shaving is pressed into the free gap G the bar 15 is providing a recess 20 at the top surface of its middle section. Whereas the height of the bars 15 at the boundary area is about 0.3 mm the height at the recessed middle area 20 is only about 0.2 mm. In addition to this 0.1 mm recess, the middle area 20 of the bar 15 is provided with a concave top surface which delivers an additional free space in the vertical of about 0.1 mm in the center. The recess 20 extends over a total width R of 1.7 mm along the axis Y. Due to free gap G of 1.00 mm the undercut U (the extent from the tip 10 to the respective bound of the recess 20 ) is 0.35 mm. This undercut U in conjunction with the recess ensures the avoidance of skin irritations during the shave.
[0031] Due to the fact that the outer cutter 5 as well as the inner cutter 13 posses U-form profiles the shaving unit 1 is distinguished by a superior mechanical stability even though using parts of only minor material thickness.
[0032] FIG. 7 shows an outer cutter 5 of a shaving unit according to the invention to be used in shavers of the rotating type with a rotating inner cutter of a type known per se and not shown in the drawing. Also this outer cutter 5 provides inwardly directed teeth 6 of two comb elements 2 and 3 . The first comb element 2 shows the form of a circle and the second comb element 3 has a ring-form and is arranged concentrically around the first comb element 2 . The geometry and the dimensions as well as the function, the effects and the advantages of this embodiment of the invention are analog to the linear version depicted above and shown in the FIGS. 1 to 6 .
[0033] As can be taken from the cross section in FIG. 8 the teeth 6 are bent to an angle in a manner that the tips 10 are elevated about a height H of 250 μm relative to the level of the outer border 8 and the inner border 21 . The free gap G between two opposite tips 10 is around 1.00 mm
[0034] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
[0035] Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
[0036] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A shaving unit for an electric shaver which comprises an outer cutter and an inner cutter associated to that outer cutter. The cutters are mounted so as to be movable relative to each other and adapted to be set in a relative motion by a drive mechanism. The inner cutter provides a plurality of cutting edges and abuts with its outer face on the inner face of the outer cutter. The outer cutter provides a plurality of teeth equipped with cutting edges. The outer cutter provides two comb elements which are disposed opposite one another and which extend according to the direction of the relative motion. The two comb elements are aligned with respect to one another such that the tips of the teeth of the first comb element are facing the tips of the teeth of the second comb element, the tips of the teeth spaced from one another. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a magnetic recording drive, a magnetic recording medium and a method for manufacturing the same and, more particularly, to a magnetic recording drive for use in an external memory device of an information processing apparatus, etc., a magnetic recording medium used therein and a method for manufacturing the same.
2. Description of the Prior Art
In the magnetic recording drive, improvement of the recording density has been demanded more and more with an increase of an amount of information in proportion. When recording density of the conventional magnetic recording medium is increased, a S/N ratio is degraded to cause reduction of a reproducing output and increase of noise. Therefore, the magnetic recording medium enabling a large reproducing output and low noise has been demanded.
In particular, the problem is to achieve noise reduction in the magnetic recording medium since reading sensitivity has been extremely improved by practical use of the magnetoresistance head.
As a main factor of generating the noise in the magnetic recording medium, there is unclear boundary of the magnetization transition regions due to variation in magnetization in magnetization transition regions. The variation in magnetization is caused by magnetic interaction between crystal grains of the ferromagnetic film constituting the ferromagnetic layer.
In order to reduce noise in the magnetic recording medium, it is required to weaken the magnetic interaction between crystal grains of the ferromagnetic film.
In general, as the recording layer of the conventional magnetic recording medium, a thin film which is formed of cobalt (Co)-based ternary or quaternary alloy by sputtering may be used. By adjusting composition of the thin film and manufacturing conditions, segregation in the ferromagnetic portion and the nonmagnetic portion can be facilitated to reduce the noise.
In the conventional magnetic recording medium, as shown in FIG. 1, for example, a chromium layer 2 , a magnetic recording layer 3 consisting of CoCr 12 Ta 2 , and a protection layer 4 consisting of a carbon film are formed in that sequence on a nonmagnetic substrate 1 which is formed of an Al substrate covered with a NiP film.
However, since a cobalt system alloy constituting the recording layer 3 is inherently a solid solution, it is difficult to isolate crystal grain of the ferromagnetic film perfectly even if segregation is accelerated by adjusting composition and manufacturing conditions.
As the way of isolating crystal grains of the magnetic substance. Patent Application Publication (KOKAI) JP59-42642 and Patent Application Publication (KOKAI) P59-220907 have set forth manufacturing methods such that a binary or ternary alloy layer comprising the nonmagnetic substance such as silver and copper and the ferromagnetic film which is insoluble in this nonmagnetic substance is once formed by sputtering, and then the alloy layer is heated.
In the manufacturing methods set forth in these publications (KOKAIs), the ferromagnetic layer is heated at a temperature of less than 400° C. to accomplish high coercive force. Since a glass or polymer film is utilized as a substrate for supporting the magnetic recording film, the heating temperature of less than 400° C. is preferable.
In both Publications, the manufacturing methods for forming the magnetic recording film which has film thickness of 130 to 150 nm and t•Br value of 2000 Gauss•μm have been set forth. The t•Br value is denoted as a product of residual magnetization Br and a film thickness t of the magnetic recording medium (magnetic recording film).
However, in the magnetic recording medium for use in the magnetoresistance head, it is requested that the thickness of the magnetic recording layer would be set to be lower than or equal to 30 nm and also the t•Br value would be set to be lower than or equal to 150 Gauss•μm. In the case of manufacturing of the magnetic recording layer, the techniques set forth in these publication cannot be applied as they are. This is because of the following reasons.
First, the relation between recording density and effective output voltage in the magnetic recording medium for use in the magnetoresistance head has been well known as described in FIG. 2 .
In FIG. 2, in case the recording density is small like about 10, 20 kFRPI, the effective output is increased if the t•Br value is increased. But, in case the recording density is large like about 50, 100 kFRPI, the effective output voltage is decreased when the t•Br value is increased.
For this reason, if the recording density is increased up to about 50, 100 kFRPI, the t•Br value of the magnetic recording layer must be set to be lower than 150 Gauss•μm.
However, even if, under the conditions set forth in the above publications, it has been tried to accomplish the t•Br value of less than 150 Gauss•μm by forming the magnetic recording layer of less than 30 nm in thickness. However, even under these conditions, noise reduction and large coercive force have not been achieved since crystal grains in the magnetic recording layer are small and further partially continuous with each other in such circumstances.
Next, it can be considered that the magnetic recording layer 3 formed of CoCr 12 Ta 2 is formed thinner. For example, as shown in FIG. 1, the chromium layer 2 of 100 nm in thickness and the magnetic recording layer 3 of 20 nm in thickness are formed in that order on the nonmagnetic substrate 1 formed of a two-layered structure consisting of Al and NiP, and then the protection layer 4 formed of carbon is formed thereon to have a thickness of 20 nm. At this time, the t•Br value is about 100 Gauss•μm.
While the relation between the recording signal frequency and noise power in the magnetic recording layer has been investigated using the magnetoresistance reproducing head, the result has been derived as shown by the broken line in FIG. 9 . It has been appreciated that noise power is increased linearly in proportion as the recording signal frequency is increased. As a result, it has been found that the thinned CoCr 12 Ta 2 is not fit for the magnetic recording layer used for high recording signal frequency.
In the examination in FIG. 2, a relative velocity between the magnetic head and the magnetic recording medium is elected as 10 m/s, the recording signal frequency is set to 20 MHz, and the recording density is selected as about 100 kFRPI.
As has been stated above, regarding a granular magnetic film (Fe-SiO 2 ) in which magnetic fine grains are dispersed into the SiO 2 film, the following problem is caused in addition to the problem of the magnetic characteristic due to crystal property of the magnetic recording film.
It has been recited in Applied Physics Letter, 52 (6), 512 (1988) and U.S. Pat. No. 4,973,525 that, in the above granular magnetic film, crystal property of the magnetic substance fine grains has been improved and also more preferable magnetic characteristics and recording/reproducing characteristics could be achieved by controlling the substrate temperature appropriately at the time of film-formation.
Thereby, there is a tendency that, in the granular magnetic film, segregation of the magnetic substance has too small size in the state of as-grown to show enough coercive force. It has been seen that, in order to increase coercive force, the annealing must be effected after growing the film to increase the volume of each segregation.
On the contrary, conventionally a NiP plated substrate has been used mainly as the substrate for the magnetic recording medium. But, the NiP layer formed on a surface of the substrate has been crystallized by heating at a temperature in excess of 300° C. Thus, there are caused some problems that flatness of the surface of the layer is damaged, the layer is magnetized, or the like. It is evident that such substrate is not adequate for heating process at a high temperature.
In recent years, it has been considered that, on the trend of downsizing, the magnetic disk is reduced in size to have the same size as the IC card. In this case, a thickness of the magnetic disk must be formed less than 3 mm. In this case, a thickness of the substrate must also be formed less than 0.3 mm, but it is the problem to use the NiP plated substrate in the respect of mechanical strength.
Like this, a glass substrate or a single crystal substrate in place of the Ni-P plated substrate is examined to proceed thinner-layered structure and planarization of the magnetic recording medium. For example, it has been proposed in Patent Application Publication (KOKAI) 59-96538 that the structure in which a chromium (Cr) layer, a magnetic film, and a protection film are grown in sequence on the single crystal substrate may be used as the magnetic recording medium.
From the previous discussion, it is of course necessary to consider that, after the Fe-SiO 2 granular magnetic film is grown in the single crystal silicon substrate, the granular magnetic film must be treated by heating process. In that case, it will be supposed that the SiO 2 film covering the granule of Fe serves to prevent the reaction between the silicon substrate and the granule.
However, based on the experiments effected by the inventors of the present invention, it has been found that, when the granular magnetic film formed on the silicon substrate is heated at a high temperature, atoms of the magnetic substance and silicon atoms are mutually diffused passing through the grain boundaries in the granular magnetic film, so that paramagnetic silicon compounds are formed to thus reduce the value of saturation magnetization (Ms) of the magnetic recording medium.
Especially, in the magnetic recording medium in which a low t•Br value (where t is a thickness of the magnetic layer, and Br is a magnitude of residual magnetization) is required to be used together with the MR head, it causes a serious problem that the magnetic grain is wasted to form silicon compounds since an amount of the magnetic grain in the magnetic film is absolutely small.
On the other hand, when the magnetic recording medium is formed of a plurality of different material layers and thereafter it is heated, there may be a risk of causing a separation of the layers due to difference between coefficients of thermal expansion of the layers.
SUMMARY OF THE INVENTION
A first object of the present invention is to provide a method for manufacturing a magnetic recording medium, which is capable of reducing noise and achieving high coercive force and is fit for a magnetoresistance head.
In the present invention, a nonmagnetic film, a ferromagnetic film and the nonmagnetic film are formed separately on a substrate, then a resultant structure is annealed to distribute crystal grains of the ferromagnetic film into the nonmagnetic film, whereby a recording layer is formed.
Thus, the crystal grains of the ferromagnetic film may be spaced and isolated from each other such that all adjacent crystal grains of the ferromagnetic film do not magnetically interact with each other in the recording layer. In this case, if the nonmagnetic substance in which the ferromagnetic film is scarcely soluble is utilized, the above tendency becomes particularly conspicuous.
Therefore, by making distribution of magnetization uniform in the magnetic recording medium, a noise characteristic can be improved which is caused by uneven distribution of magnetization in magnetization transition regions and their peripheral regions of the magnetic recording medium.
Furthermore, according to the above manufacturing method, such a recording layer can be formed that has a thin film thickness, realizes satisfactory coercive force, and attains 150 Gauss•μm or less, preferably 100 Gauss•μm or less in a product of residual magnetic flux density and a film thickness. As a result, large reproducing output which is fit for high sensitivity performance of the MR head can be obtained.
In addition, if the magnetic recording layer is annealed at a high temperature, for example, 400° C. or more so as to facilitate mutual diffusion and also to produce crystal structures for generating sufficient magnetization as distributed crystal grains of the ferromagnetic film, further large coercive force can be obtained.
In the above description, as a substance of the ferromagnetic film, cobalt or an alloy including the cobalt as a major constituent, for instance. Co A Cr 100-A (A is 90 or more), Co A Pt 100-A (A is 70 or more, or 40 to 50) or Co A Sm 100-A (A is 83.3 or 89.5) may be used. As a substance of the nonmagnetic film, metal, oxide, nitride, carbon or carbide may be used.
Moreover, as a substance of the nonmagnetic film, it is preferable to use a substance which has a solid solubility of cobalt of 5% or less, for instance, metal such as silver or copper, silicon oxide or zirconium oxide, titanium nitride or silicon nitride, carbon or carbide, or the like.
Also, a high heat-resistant material, for instance, silicon or carbon, is suitable for a substrate of the nonmagnetic substrate.
In addition, in the present invention, the magnetic recording layer of an alloy consisting of the ferromagnetic film and the nonmagnetic substance is formed on the heat-resistant nonmagnetic substrate to have a thickness of 30 nm or less, and then the magnetic recording layer is annealed during it is being formed or after it is formed, whereby plural isolated grains formed of the ferromagnetic film and having an average grain diameter of 50 nm or less are obtained.
In the magnetic recording layer thus formed, since the grains of the ferromagnetic film can be formed to have large size and isolated from each other, variations in magnetization in magnetization transition portions can be suppressed. Therefore, in contrast to the conventional device, noise can be reduced upon recording or reproducing signals, and dependency of noise power on recording signal frequency can also be eliminated.
Also, in the case in which the magnetic recording layer having a film thickness of less than 30 nm is formed, it has been experimentally confirmed that coercive force of the magnetic recording layer may be increased if an annealing temperature is set at 400° C. or more, preferably in a range of 400° to 550° C. while coercive force may be increased if the annealing temperature is set at 400° C. or less.
Accordingly, the magnetic recording layer having high signal quality (high S/N and high recording density may be obtained.
Besides, if a t•Br value of the magnetic recording layer is set lower than or equal to 150 Gauss•μm, the magnetic recording layer is most suitable for the magneto-resistance head.
A second object of the present invention is to provide a magnetic recording medium capable of preventing a separation of layers constituting it and suppressing degradation of coercive force by preventing a reaction between silicon in the silicon substrate and magnetic substance in a granular magnetic film, and a method for manufacturing the same, and a magnetic recording device utilizing such magnetic recording medium.
According to the present invention, the nonmagnetic layer including no magnetic grain therein is formed between the nonmagnetic layer including magnetic grains therein and the silicon substrate. The nonmagnetic layer including the magnetic grains therein serves as the granular magnetic layer, and the nonmagnetic layer including no magnetic grain therein serves as a diffusion preventing layer. Thus, mutual diffusion of the silicon in the silicon substrate and the magnetic grain due to annealing may be prevented by the diffusion preventing layer.
Therefore, since the silicon containing the magnetic material is not formed, reduction of the magnetic material may be prevented so that the magnetic recording medium having large coercive force and high recording density can be achieved. In addition, since the granular magnetic layer and the diffusion preventing layer excepting the magnetic fine grains are formed by the same substance, difference in thermal stress does not occur in the granular magnetic layer and the diffusion preventing layer. Thus, a stable layer structure can be obtained without the possibility of film exfoliation. A silicon oxide film, for example, can be listed as the nonmagnetic layer. There are iron, cobalt and nickel, for example, as the magnetic grain. Further, an adhesion between a silicon dioxide layer and a silicon substrate is extremely superior and there is no risk of a separation therebetween.
Besides, it may be considered to form the diffusion preventing layer with nonmagnetic material which has the same coefficient of thermal expansion as the nonmagnetic material constituting a granular magnetic layer and the different composition from it. However, it requires much labor that two kinds of nonmagnetic material need to be separately alloyed. In order to avoid this, it is preferable that their kinds are same.
If a product (t•Br) of a thickness (t) and residual magnetization (Br) of the granular magnetic layer is set at 100 Gauss•μm or less in such structure, the magnetic recording medium which is most suitable for signal detection by the magnetoresistance head can be derived.
Incidentally, in the case the silicon substrate is heated, it is neither magnetized nor deformed even if it is heated at a temperature in excess of 300° C., for example, 1000° C.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a conventional magnetic recording medium;
FIG. 2 is a view showing a typical relation between recording density and effective output voltage in the magnetic recording medium;
FIGS. 3A to 3 C are sectional views showing a method for manufacturing a magnetic recording medium according to a first embodiment of the present invention;
FIG. 4 is a characteristic view showing the measured result of noise power of the magnetic recording medium manufactured by the manufacturing method according to the first embodiment of the present invention;
FIG. 5 is a sectional view showing a magnetic recording medium formed by a manufacturing method according to a second embodiment of the present invention;
FIG. 6 is a sectional view showing a magnetic recording medium formed by a manufacturing method according to a third embodiment of the present invention;
FIGS. 7A to 7 C are sectional views showing respectively manufacturing steps of a magnetic recording medium according to a fourth embodiment of the present invention;
FIG. 8A is a schematic view showing a construction of a sputtering apparatus used to form a magnetic recording layer;
FIG. 8B is a plan view showing a target for use in sputtering process;
FIG. 9 is a view showing relations between recording signal frequency and noise power in the magnetic recording medium according to the fourth embodiment of the present invention and the conventional magnetic recording medium;
FIG. 10 is a view showing a relation between a substrate temperature and coercive force when a magnetic recording layer according to a fifth embodiment of the present invention being formed;
FIG. 11 is a sectional view showing a magnetic recording medium according to the fifth embodiment of the present invention;
FIG. 12 is a view showing a relation between a film thickness and coercive force in a magnetic recording layer according to a sixth embodiment of the present invention;
FIG. 13 is a sectional view showing the magnetic recording medium according to a seventh embodiment of the present invention;
FIGS. 14A to 14 D are sectional views showing a magnetic recording medium and manufacturing steps therefor according to an eighth embodiment of the present invention;
FIG. 15 is a sectional view showing a comparative sample in the case in which the present invention is not applied;
FIG. 16 is a view showing relations between an annealing temperature and saturation magnetization respectively in the magnetic recording medium which is formed on the silicon substrate via an SiO 2 film according to the eighth embodiment of the present invention and the magnetic recording medium which is formed directly on the silicon substrate;
FIG. 17 is a view showing the result of X-ray diffraction of a granular magnetic layer executed immediately after it is grown via the SiO 2 film on the silicon substrate according to the eighth embodiment of the present invention;
FIG. 18 is a view showing the result of X-ray diffraction of the granular magnetic layer executed immediately after it is grown directly on the silicon substrate according to the comparative example;
FIG. 19 is a view showing the result of X-ray diffraction of the granular magnetic layer after it is formed via SiO 2 film on the silicon substrate and then annealed at 800° C. for ten minutes according to the eighth embodiment of the present invention;
FIG. 20 is a view showing the result of X-ray diffraction of the granular magnetic layer after it is formed directly on the silicon substrate according to the comparative example and then annealed at 800° C. for ten minutes;
FIG. 21 is a view showing a relation between an annealing temperature and coercive force in the magnetic recording medium formed via the SiO 2 film on the silicon substrate according to the eighth embodiment of the present invention;
FIG. 22 is a plan view showing an example of the magnetic recording device having the magnetic recording medium according to embodiments of the present invention; and
FIGS. 23A to 23 C are sectional views showing details around the MR head and the magnetic recording medium in the magnetic recording device shown in FIG. 22, wherein FIG. 23A shows an in-gap type MR head. FIG. 23B shows a common type MR head, and FIG. 23C shows a yoke type MR head.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
There will now be described preferred embodiments of the present invention hereinafter with reference to the accompanying drawings.
(1) Explanation of a method for manufacturing a magnetic recording medium according to a first embodiment of the present invention:
FIGS. 3A to 3 C are sectional views showing a manufacturing method of the magnetic recording medium according to the first embodiment of the present invention.
First, as shown in FIG. 3A, a silver (Ag) film (nonmagnetic film) 12 having a film thickness of 5 nm is formed by sputtering on a silicon substrate (nonmagnetic substrate) 11 having a diameter of 2.5 inch, for example, under the conditions that argon pressure is 5 mTorr, a substrate temperature is 20° C., a DC power is 0.2 kW, and a DC bias voltage is not applied.
Then, a cobalt (Co) film (ferromagnetic film) 13 of 7 nm in film thickness is formed on the silver film 12 by sputtering under the conditions that argon pressure is 5 mTorr, a substrate temperature is 20° C., a DC power is 0.2 kW, and a DC bias voltage is not applied.
Subsequently, a silver (Ag) film 14 having a film thickness of 5 nm is formed on the cobalt film 13 by sputtering under the conditions that argon pressure is 5 mTorr, a substrate temperature is 20° C., a DC power is 0.2 kW, and a DC bias voltage is not applied. Film thicknesses of the silver films 12 , 14 and the cobalt film 13 are determined such that a product (t•Br) of residual magnetic flux density (Br) and a film thickness (t) of the recording layer is about 100 Gauss•μm.
Next, in low pressure atmosphere having pressure of less than 5×10 −6 Torr, annealing process is effected at a temperature of 450° C. for 60 minutes. Oxidation of the silver films 12 , 14 and the cobalt film 13 can be prevented because of low pressure atmosphere, and silver and cobalt are mutually diffused according to the annealing temperature. As shown in FIG. 3B, cobalt is crystallized to thus form cobalt crystal grains 13 a having several nm or several tens nm in size, so that they are spread into the silver film 15 and the crystal grains 13 a are isolated from each other. Thereby, the recording layer 16 in which the crystal grains 13 a of cobalt are dispersed into the silver film 15 is formed. Since the cobalt film 13 is formed to be continuous before annealing process, its coercive force can be small. By annealing process, the crystal grains 13 a of cobalt are scattered into the recording layer 16 , so that large coercive force can be attained. Furthermore, if crystal structures of cobalt are formed as hexagonal closet packet (hcp) structures by annealing process, larger coercive force can be attained.
In addition, it is necessary to adjust the annealing temperature suitably according to material of the nonmagnetic film and the ferromagnetic film. In general, if substances of the nonmagnetic film and the ferromagnetic film having higher melting points, then the required annealing temperature is increased in proportion. It has been found from our experiments that, if the annealing temperature exceeds 400° C., mutual diffusion of silver and cobalt occurs within a practical annealing temperature, and also the hcp structures can readily be formed as crystal structures of the cobalt crystal grains 13 a. Therefore, annealing time can be properly adjusted in a range of the annealing temperature in excess of 400° C.
Then, as shown in FIG. 3C, a carbon (C) film 17 of 10 nm in film thickness is formed on the recording layer 16 by sputtering under the conditions that argon pressure is 10 mTorr, a substrate temperature is 20° C., a DC power is 1 kW, and a DC bias voltage is not applied, thus completing a magnetic recording medium.
Next, the measured result of noise power with respect to the above magnetic recording medium will be explained.
FIG. 4 is a characteristic view showing the dependency of noise power on the recording frequency. The abcisa indicates a recording frequency (MHz) represented in a linear scale while the ordinate indicates noise power represented in arbitrary unit.
For purposes of comparison, noise power with respect to the magnetic recording medium according to the comparative example is also given in the characteristi view of FIG. 4 . The magnetic recording medium according to the comparative example has the structure shown in FIG. 1 . More particularly, the chromium film 2 having a thickness of 100 nm, the recording layer 3 made of CoCr 12 Ta 2 film having a thickness of 20 nm, and the protection layer 4 made of the carbon film having a thickness of 20 nm were formed in that order on the nonmagnetic recording medium 1 which is formed of an Al substrate covered with a Ni-P film. The t•Br product of the magnetic recording medium in FIG. 1 is set as about 100 Gauss•μm.
The MR head was used as the reproducing head. At this time, the circumferential velocity (i.e., relative velocity between the head and the magnetic recording medium) was selected as 10 m/s, and the recording density wa about 100 (KCFI) at the recording frequency of 20 MHz.
It has been seen from FIG. 4 that noise power hardly changes with respect to the recording frequency in the magnetic recording medium according to the first embodiment, whereas noise power significantly changes with the recording frequency in the magnetic recording medium according to the conventional example. Particularly, noise power increases linearly with increase of the recording frequency.
In the frequency range lower than the recording frequency of 12 to 13 MHz, noise power caused by the magnetic recording medium according to the comparative example is smaller. On the contrary, in the frequency range higher than the recording frequency of 12 to 13 MHz, noise power caused by the magnetic recording medium according to the first embodiment is smaller. For example, assuming that noise power of the comparative example is set as 1 at the recording frequency of 20 MHz, noise power of the first embodiment becomes 0.8 at the same frequency, as shown in Table 1. Accordingly, the magnetic recording medium according to the first embodiment is favorable to the high frequency range.
As discussed earlier, in the manufacturing method of the magnetic recording medium according to the first embodiment of the present invention, in order to form the recording layer 16 , the silver film (nonmagnetic film) 12 , the cobalt film (ferromagnetic film) 13 , and the silver film (nonmagnetic film) 14 are formed in this sequence and separately, then crystal grains 13 a of cobalt (ferromagnetic film) are dispersed into the silver film 15 by annealing process.
Consequently, the crystal grains 13 a of cobalt may be isolated in the recording layer 16 such that they are separated not to magnetically interact each other. Thus, magnetization distribution can be made uniform in the recording layer 16 , so that the noise characteristic due to uneven magnetization distribution in magnetization transition regions and their peripheral regions of the magnetic recording medium can be improved.
Further, according to the above manufacturing method, since such as recording layer 16 can be formed that has a thin film thickness, realizes satisfactory coercive force, and accomplishes a product t•Br of 100 Gauss•μm or less, large reproducing output which is fit for high sensitivity performance of the MR head can be derived.
In addition, although the silver film is used as the non-magnetic films 12 , 14 in the first embodiment, a copper film may be used.
In the first embodiment, since annealing process at relatively high temperature is sometimes needed according to several kinds of materials used as the nonmagnetic films 12 , 14 and the ferromagnetic film 13 , the silicon substrate having excellent heat-proof property is used as the nonmagnetic substrate 11 . But, a carbon substrate having excellent heat-proof property may be used similarly.
(2) Explanation of a method for manufacturing a magnetic recording medium according to a second embodiment of the present invention:
FIG. 5 is a sectional view showing a magnetic recording medium manufactured by a manufacturing method according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that a carbon film is used in place of the silver films between which the cobalt film is put. Also, since a carbon film 18 is utilized on the uppermost portion of the recording layer 19 , the protection layer is shared with the carbon film 18 on the recording layer 19 .
Referring to FIG. 5, the second embodiment of the present invention will be explained hereinafter.
First, a carbon film (nonmagnetic film) having a film thickness of 5 nm is formed by sputtering on a silicon substrate (nonmagnetic substrate) 11 under the conditions that argon pressure is 10 mTorr, a substrate temperature is 20° C., an AC power having a frequency of 13.56 MHz is 0.2 kW, and a DC bias voltage is not applied.
In turn, a cobalt film (ferromagnetic film) of 5 nm in film thickness is formed on the carbon film by sputtering under the conditions that argon pressure is 5 mTorr, a substrate temperature is 20° C., a DC power is 0.2 kW, and a DC bias voltage is not applied.
Then, the carbon film having a film thickness of 7 nm is formed on the cobalt film by sputtering under the conditions that argon pressure is 5 mTorr, a substrate temperature is 20° C., an AC power having a frequency of 13.56 MHz is 0.2 kW, and a DC bias voltage is not applied.
Next, in low pressure atmosphere of a degree of vacuum of less than 5×10 −6 Torr, annealing process is effected at a temperature of 450° C. for 60 minutes. Thereby, oxidation of the carbon films and the cobalt film can be prevented, and carbon and cobalt are mutually diffused. As a result, the recording layer 19 in which crystal grains 13 b of cobalt having several nm or several tens nm in size are dispersed into the carbon film 18 can be formed. At this time, since the cobalt film is formed to be continuous before annealing process, its coercive force can be small. By annealing process, the crystal grains 13 b of cobalt are scattered into the recording layer 19 , so that large coercive force can be attained. Further, if crystal structures of cobalt are formed as the hcp structures by annealing process, larger coercive force can be attained.
As has been described above, the magnetic recording medium has been finished.
As shown in Table I below, assuming that noise power in the conventional example is regarded as 1 at recording frequency of 20 MHz, noise power of the magnetic recording medium manufactured as above can be obtained as 0.8 which is lower than that in the conventional example.
TABLE I
FERROMAGNETIC
NONMAGNETIC LAYER
LAYER
NOISE POWER
Ag
Co
0.8
Ag
Co 90 Cr 10
0.75
Ag
Co 80 Pt 20
0.8
Ag
Co 50 Pt 50
0.8
Ag
Co 80 Sm 20
0.8
Ag
Co 89.5 Sm 10.5
0.8
C
Co
0.8
C
Co 90 Cr 10
0.75
C
Co 80 Pt 20
0.8
C
Co 50 Pt 50
0.8
C
Co 80 Sm 20
0.8
C
Co 89.5 Sm 10.5
0.8
Cu
Co
0.85
Cu
C 90 Cr 10
0.8
Cu
Co 80 Pt 20
0.8
Cu
Co 50 Pt 50
0.8
Cu
Co 80 Sm 20
0.8
Cu
Co 89.5 Sm 10.5
0.8
TiN
Co
0.85
TiN
Co 90 Cr 10
0.8
TiN
Co 80 Pt 20
0.75
TiN
Co 50 PT 50
0.8
TiN
Co 80 Sm 20
0.8
TiN
Co 89.5 Sm 10.5
0.8
SiO 2
Co
0.8
SiO 2
Co 90 Cr 10
0.85
SiO 2
Co 80 Pt 20
0.8
SiO 2
Co 50 Pt 50
0.8
SiO 2
Co 80 Sm 20
0.75
SiO 2
Co 89.5 Sm 10.5
0.8
SiN
Co
0.8
SiN
Co 90 Cr 10
0.85
SiN
Co 80 Pt 20
0.8
SiN
Co 50 Pt 50
0.8
SiN
Co 80 Sm 20
0.75
SiN
Co 89.5 Sm 10.5
0.8
ZrO 2
Co
0.8
ZrO 2
Co 90 Cr 10
0.8
ZrO 2
Co 80 Pt 20
0.85
ZrO 2
Co 50 Pt 50
0.8
ZrO 2
Co 80 Sm 20
0.75
ZrO 2
Co 89.5 Sm 10.5
0.8
Although the protection layer is not particularly formed on the recording layer 19 , the protection layer may be formed with a carbon film or the like additionally as the case may be.
(3) Explanation of a magnetic recording medium according to a third embodiment of the present invention:
FIG. 6 is a sectional view showing a magnetic recording medium formed by a manufacturing method according to a third embodiment of the present invention.
The third embodiment is different from the first and second embodiments in the respect that a Co 90 Cr 10 film may be used in place of the cobalt film as the ferromagnetic film sandwiched with the nonmagnetic films.
In comparison with the Co film, the crystal structures of crystal grains of the ferromagnetic film are readily formed as the hcp structures in the Co 90 Cr 10 film, because of existence of Cr therein. Thus, the Co 90 Cr 10 film has a feature that high coercive force can easily be obtained.
A film forming method is the same as that used for the Co film, which has been explained in the first and second embodiments. As a result, the recording layer 21 in which the crystal grains 13 of Co 90 Cr 10 are dispersed into the silver film 20 and mutual crystal grains 13 c are perfectly isolated can be formed on the silicon substrate (nonmagnetic substrate) 11 .
In this case, as shown in Table I above, assuming that noise power in the conventional example is regarded as 1 at recording frequency of 20 MHz, noise power of the magnetic recording medium manufactured as above can be obtained as 0.75 which is lower than that in the conventional example.
In the magnetic recording medium according to the first to third embodiments, the silver film or the carbon film in which Co is not soluble has been used as the non-magnetic films 12 , 14 sandwiching the ferromagnetic film 13 . Alternatively, any one of SiO 2 film, ZrO 2 film, TiN film and SiN film into which Co is seldom soluble may be used.
As a substance of the ferromagnetic film 13 , Co A Pt 100-A (A is 70 or more, or 40 to 50) or Co A Sm 100-A (A is 83.3 or 89.5) may be used in addition to Co or Co 90 Cr 10 .
Regarding the nonmagnetic substance and the ferromagnetic substance. Table I shows measured data of noise power caused by the magnetic recording medium if various combinations of the nonmagnetic substance and the ferromagnetic substance are utilized. It is understood that noise power becomes smaller than 1 if noise power in the conventional example is assumed as 1.
In the manufacturing method of the magnetic recording medium according to the third embodiment of the present invention, in order to form the recording layer, the nonmagnetic film, the ferromagnetic film, and the nonmagnetic film are formed in that order and separately, then crystal grains of the ferromagnetic film are dispersed into the nonmagnetic film by annealing process.
Consequently, the crystal grains of the ferromagnetic film may be isolated in the recording layer such that they are separated not to magnetically interact each other. Thus, magnetization distribution can be made uniform in the recording layer. As a result, the undesirable noise characteristic due to uneven magnetization distribution in magnetization transition regions and their peripheral regions of the magnetic recording medium can be improved.
Furthermore, such a recording layer can be formed that has a thin film thickness, realizes satisfactory coercive force, and attains a product t•Br of less than 100 Gauss•μm. Therefore, large reproducing output which is fit for high sensitivity performance of the MR head can be derived.
(4) A fourth embodiment of the present invention:
FIGS. 7A to 7 C are sectional views showing manufacturing steps of the magnetic recording medium according to the fourth embodiment of the present invention. FIG. 8A is a schematic view showing the sputtering apparatus used for staking the ferromagnetic material and the nonmagnetic material. FIG. 8B is a plan view showing a target used for sputtering process.
To manufacture the magnetic recording medium, the sputtering apparatus shown in FIG. 8A is employed. First, a heat-resistant and nonmagnetic substrate 21 having a diameter of 2.5 inch is fixed on a wafer holder 32 in a chamber 31 . As the heat-resistant and nonmagnetic substance 21 , the silicon substrate or the carbon substrate which can stand heat in excess of 400° C. for example, may be used.
In addition, a target 34 shown in FIG. 8B is also placed on a target supporting bed 33 . The target 34 is formed by arranging a plurality of sectoral magnetic plates 34 b discretely on a nonmagnetic target 34 a. The target 34 is fixed on the target supporting bed 33 by a frame body 35 . In the fourth embodiment, the silver (Ag) plate is used as the nonmagnetic target 34 a while the cobalt (Co) plate is used as the magnetic plate 34 b.
In this state, argon gas is introduced in the chamber 31 via a gas introducing portion 37 while the gas in the chamber 31 is being exhausted from an exhaust port 36 , thus holding pressure in an interior of the chamber 31 at 5 mTorr.
Then, after a substrate temperature is not heating, high frequency power of 0.2 kW is applied between the target supporting bed 33 and the wafer holder 33 from a high frequency power source serving as a sputtering power source 38 .
Under these sputtering conditions, as shown in FIG. 7A, a magnetic recording layer 25 made of an alloy consisting of a ferromagnetic film 22 and a nonmagnetic substance 23 is formed on the heat-resistant and nonmagnetic substrate 21 to have a thickness of 10 nm. By use of the above target 34 , the ferromagnetic films 22 are distributed uniformly into an entire area of the magnetic recording layer 25 . A containing rate of the ferromagnetic film 22 in the magnetic recording layer 25 can be controlled by varying the number of sheet of the magnetic plate 34 b arranged in the target 34 .
If Co is used as the ferromagnetic film 22 and Ag is used as the nonmagnetic substance 23 , sizes of the crystal grains of Co are small, like less than or equal to several nm, and plural crystal grains are formed in the film thickness direction. In addition, in some cases, some of the crystal grains are coupled partially with each other. As a result, it becomes unavoidable that the magnetic recording layer 25 has only small coercive force and that variation in magnetization is increased in the magnetization transition regions.
Hence, in case the nonmagnetic substrate 21 on which the magnetic recording layer 25 is formed is heated at a temperature of 500° C. for ten minutes in a heating furnace (not shown), Ag and Co are separately segregated in the recording layer, as shown in FIG. 7 B. The crystal grains of Co are completely isolated to have a diameter of 50 nm or less if viewed from the upper side. Also, the size of the crystal grain is formed such that only one crystal grain of Co exists in the direction of the film thickness. This resultant layer may be used as the magnetic recording layer 25 . Consequently, it has been found that large crystal grains of Co are grown, and the crystal grains are formed not to be coupled with each other, and also the crystal grains of Co are covered with Ag. This is because Ag and Co are mutually insoluble.
According to the magnetic recording layer 25 , it has been confirmed that high coercive force can be derived, variation in magnetization can be small in the magnetization transition regions, and noise power can be reduced when magnetic recording information are read out.
Here the t•Br value of the magnetic recording layer 25 having a film thickness of 10 nm can be obtained as about 100 Gauss•μm. Therefore, the magnetic recording layer 25 can provide a large amplitude output in a state of high recording density if it being used together with the magnetoresistance head.
After the magnetic recording layer 25 is formed as above, as shown in FIG. 7C, a protection film 26 made of carbon is then formed by sputtering on the magnetic recording layer 25 to have a thickness of 10 nm. As the sputtering conditions, a carbon plate is used as the target, pressure of argon gas atmosphere is set at 10 mTorr, a substrate temperature is not heating, and a DC power of 1 kW is applied between the target supporting bed 33 and the wafer holder 32 as the sputtering power source 38 .
In FIG. 9, a solid line shows the relation between noise power and recording signal frequency, which has been investigated when recording information are read from the magnetic recording medium including the magnetic recording layer 25 formed as above. The noise power does not depend on the magnitude of the recording signal frequency to be virtually constant. If the recording signal frequency exceeds about 13 MHz, noise power can be reduced in contrast to the conventional magnetic recording medium shown in FIG. 9 .
Using the magnetoresistance head, noise power has been measured in a state wherein the relative velocity between the MR head and the magnetic recording medium (circumferential velocity) is selected as 10 m/s. Now the recording density is 100 kFRPI when the recording signal frequency is selected as 20 MHz.
(5) A fifth embodiment of the present invention:
In the fourth embodiment, the magnetic recording layer 25 is heated at 500° C. after being formed on the heat-resistant nonmagnetic substrate 21 . This heating process may be executed simultaneously in the course of stacking the magnetic recording layer 25 . According to this process, the same advantage as that in the fourth embodiment can also be obtained.
Therefore, by examining change of coercive force in the magnetic recording medium due to difference in heating process to form the magnetic recording layer 25 , the result shown in FIG. 10 has been obtained.
According to FIG. 10, it has been found that coercive force is increased abruptly around 400° C. and is at a maximum at 500° C. if the substance temperature is further increased, and that coercive force is then gradually decreased with further increase of the substance temperature. Thus, high coercive force and low substance noise can be obtained over the temperature range of 400° to 550° C.
Then, in case the annealing temperature is set to 400° C., a sectional shape of the magnetic recording medium 27 is shown in FIG. 11 . The ferromagnetic film 22 is turned into isolated grains, and the size thereof is substantially identical to that of the fourth embodiment.
The same conditions as those in the first embodiment have been used as conditions for forming the magnetic recording layer 27 except for the substrate temperature to accomplish the result in FIG. 10 . In addition, the same conditions as those in the fourth embodiment except for no heating of the substrate are also employed to grow the protection film 26 .
(6) A sixth embodiment of the present invention:
Although Co has been used as the ferromagnetic material contained in the magnetic recording layers 25 , 27 in the fourth and fifth embodiments, iron, cobalt-chromium alloy etc. may be used. As the nonmagnetic substance, copper (Cu) in which such ferromagnetic film is not soluble may be used in addition to Ag.
The magnetic recording layers have been manufactured by heating mixed layers having combinations of the ferromagnetic film and the nonmagnetic substance shown in Table II below at 500° C. Then noise power caused by respective magnetic recording layers has been checked. It has been appreciated that such noise power are smaller than those in the conventional magnetic recording layer. Respective noise powers in Table II are comparative values if noise power in the conventional magnetic recording medium is assumed as 1.
TABLE II
FERROMAGNETIC
NONMAGNETIC LAYER
LAYER
NOISE POWER
Ag
Co
0.8
Ag
Co 90 Cr 10
0.75
Ag
Co 80 Pt 20
0.8
Ag
Co 50 Pt 50
0.8
Ag
Co 80 Sm 20
0.8
Ag
Co 89.5 Sm 10.5
0.8
Ag
Fe
0.75
Cu
Co
0.85
Cu
Co 90 Cr 10
0.8
Cu
Co 80 Pt 20
0.75
Cu
Co 50 Pt 50
0.8
Cu
Co 80 Sm 20
0.8
Cu
Co 89.5 Sm 10.5
0.8
Cu
Fe
0.75
The magnetic recording medium in which the CoCr 12 Ta 2 having a thickness of 20 nm is formed on the substrate, as shown in FIG. 1, was used as the conventional magnetic recording medium.
The recording signal frequency is selected as 20 MHz at the time of measuring noise power.
Referring to Table II, it has bene confirmed that, if the magnetic recording layer comprising the nonmagnetic substance and the ferromagnetic film, both being mutually insoluble, is formed and then heated at 500° C., noise power in the magnetic recording layer can be reduced.
In any circumstances, if Ag is used as the nonmagnetic substance and also Co 90 Cr 10 is used as the ferromagnetic film and both substances are formed on the nonmagnetic substance having heat-proof property in excess of 400° C., the crystal grains of the ferromagnetic film are readily formed as the hcp structures. Thus, high coercive force can easily be obtained in comparison with the case where the magnetic recording layer is formed with Co. In the case where Fe, Co x Cr 100-x (x is 90 or more). Co y Pt 100-y (y is 70 or more, or 40 to 50) or Co A Sm 100-A (A is 77.3 or 80 or more) may be used as a substance of the ferromagnetic film, the advantages can be obtained.
If the relation between the film thickness of the magnetic recording layer and coercive force by the magnetic recording layer after the magnetic recording layer consisting of Ag serving as the nonmagnetic substance and Fe serving as the ferromagnetic film has been formed under the conditions given in the fourth embodiment, the result shown in FIG. 12 has been derived. According to FIG. 12, it has been found that large coercive force can be derived if the film thickness of the magnetic recording layer is set over a range of 50 nm to 10 nm (500 Å to 100 Å). With reference to all combinations of the ferromagnetic films and the nonmagnetic substances listed in Table II, this relation has also been derived.
(7) A seventh embodiment of the present invention:
In any case, if the silicon substrate is used as the heat-resistant and nonmagnetic substrate 21 shown in the above embodiments, silicon is diffused into the ferromagnetic substance 22 in the magnetic recording layer 25 , otherwise the ferromagnetic film 22 is readily diffused into the silicon substrate. Thus, there is a possibility such diffusion causes degradation of magnetic characteristics of the magnetic recording layer.
Hence, as shown in FIG. 13, it would be preferable to prevent diffusion of silicon and the ferromagnetic film by intervening a barrier layer 29 between the magnetic recording layer 25 and a nonmagnetic wood ash 21 formed of silicon. As the barrier layer 29 , SiO 2 film may be used which is formed by oxidizing a surface of the silicon substrate so as to have a film thickness of about 300 nm, for example.
According to the fourth to seventh embodiments aforementioned, the magnetic recording layer made of the alloy consisting of the ferromagnetic film and the nonmagnetic substance is formed on the heat-resistant and nonmagnetic substrate to have a thickness of less than 30 nm, and further the magnetic recording layer is heated in excess of 400° C. during it is formed or after it is formed, to thus form plural isolated grains made of the ferromagnetic substance and having an average grain diameter of 50 nm or less. Therefore, grains of the ferromagnetic film can grow large, and variation in magnetization in the magnetization transition regions can be reduced. As a result, in contrast to the conventional recording medium, noise can be reduced upon recording/reproducing signals as well as the dependency of noise power on the recording signal frequency can also be reduced.
Also, coercive force of the magnetic recording layer may be increased by setting an annealing temperature at more than 400° C., preferably in a range of 400° to 550° C.
(8) An eighth embodiment of the present invention:
FIGS. 14A to 14 D are sectional views showing manufacturing steps of a magnetic recording medium according to an eighth embodiment of the present invention.
First, as shown in FIG. 14A, a diffusion preventing layer 42 made of SiO 2 (silicon dioxide) is formed on a single crystal silicon substrate 41 by sputtering or thermal oxidation to have a thickness of 100 nm.
Then, as shown in FIG. 14B, a granular magnetic film 43 in which magnetic fine grains 43 g like iron (Fe) is diffused into the SiO 2 43 s is formed on the diffusion preventing layer 42 by sputtering to have a thickness of 100 nm. The granular magnetic film 43 is grown at a substrate temperature of a room temperature (a normal temperature) and in argon atmosphere.
After this, as shown in FIG. 14C, crystal property of the magnetic film grains can be improved by annealing process in inert gas atmosphere.
Subsequently, as shown in FIG. 14D, a protection film 44 made of carbon (C) and having a thickness of 15 nm is formed on the granular magnetic film 43 . Thereafter, the magnetic recording medium has been completed by coating a lubricant on the protection film 44 .
To examine the effect produced by annealing process of the magnetic recording medium having the structure set forth above, a comparative sample without the diffusion preventing layer is also prepared. As shown in FIG. 15, this comparative sample has such a structure that the granular magnetic film 52 is formed directly on the single crystal silicon substrate 51 without an interposition of the diffusion preventing layer. The granular magnetic film 52 is constituted by dispersing the fine grains 53 g of the magnetic substance into the SiO 2 53 s. Manufacturing conditions of the comparative sample are selected to be the same as in FIGS. 14A and 14B excluding the diffusion preventing layer.
Examinations have been tried to check how respective granular magnetic layers 43 and 53 in the magnetic recording medium shown in FIG. 14 B and the comparative sample in FIG. 15 are changed by annealing process.
(Change of Saturation Magnetization)
When changes in the value of saturation magnetization (Ms) caused by annealing process is examined, the result shown in FIG. 16 can be derived. In FIG. 16, a solid line indicates a characteristic between annealing temperature vs saturation magnetization of the magnetic recording medium shown in FIG. 14C, while a broken line indicates a characteristic between annealing temperature vs. saturation magnetization of the comparative sample shown in FIG. 15 . Here the abscissa indicates an annealing process temperature and the ordinate indicates a magnitude Ms (emu/cc) of saturation magnetization of the magnetic recording medium after the annealing process has been done.
As may be evident from the broken line in FIG. 16, in the comparative sample without the diffusion preventing layer, the value of Ms is decreased in proportion with increase of the temperature used for the annealing process. Since reduction of Ms in the magnetic recording medium causes reduction of the reproducing output, it is not preferable to anneal the comparative sample. The value of Ms still remains low unless the annealing process is executed yet.
As may be apparent from the solid line in FIG. 16, according to the magnetic recording medium of the eighth embodiment, it has been understood that the value of Ms is increased in proportion to increase of the annealing temperature. In order to obtain a high output at the time of reproducing information, the higher the Ms becomes, the more advantageous it become.
Like this, in both cases where the SiO 2 diffusion preventing layer 42 is intervened between the silicon substrate and the granular magnetic film and no diffusion preventing layer is intervened, the following is the reason why the value of M becomes different by the annealing process.
In other words, this is because the magnetic fine-grains 53 g formed of iron and silicon in the silicon substrate 51 are mutually diffused by heat in the comparative sample to generate silica iron, and therefore an amount of the magnetic substance is reduced. It can be considered that silicon elements and iron are diffused via the boundary between the magnetic fine grains 53 g and the SiO 2 53 s in the granular magnetic film 53 of the comparative sample.
On the other hand, in the eight embodiment shown in FIG. 14B, since mutual diffusion of silicon and the magnetic fine grains 43 a by heat is prevented by the diffusion preventing layer 42 , an amount of the magnetic substance is not reduced, and also sizes of the fine grains are increased by heat treating.
Next, as shown in FIG. 14B, it has been examined by the XRD (X-ray diffraction) how respective crystal structure of the granular magnetic film 43 , which is formed on the silicon substrate 41 via the SiO 2 diffusion preventing layer 42 , and of the granular magnetic film 53 , which is directly formed on the silicon substrate 51 shown in FIG. 15, are changed by the annealing process.
FIG. 17 shows the measurement result of XRD of the granular magnetic film 43 immediately after the magnetic film 43 being formed on the silicon substrate 41 via the SiO 2 diffusion preventing layer 42 . While, FIG. 18 shows the measurement result of XRD of the granular magnetic film 53 immediately after the magnetic film 53 being directly on the silicon substrate 51 .
If the result in FIG. 17 is compared with the result in FIG. 18, there exists no remarkable difference between the X-ray diffraction spectra of both granular magnetic films 43 and 53 . In detail, it scarcely causes great difference in crystal properties between the granular magnetic films 43 and 53 before annealing process, whether the SiO 2 diffusion preventing layer 42 including no iron is provided or not. The fact that crystal grains of the magnetic grains 43 g, 53 g in both granular magnetic films 43 , 53 are very small under the as-grown condition without annealing may be considered as the reason why the X-ray diffraction ray from both granular magnetic films 43 and 53 shows weak strength.
Then, the XRD measurement results are shown in FIGS. 19 and 20 which are obtained after the granular magnetic film is annealed at 800° C. for ten minutes.
FIG. 19 shows the XRD measurement result obtained after the granular magnetic film 43 in the magnetic recording medium shown in FIG. 14B is annealed. According to the measurement result, it has been found that only α-Fe diffraction rays appear as peaks, and the peaks have a large amplitude. In addition, no peak from a compound of iron and silicon is watched. The reason may be deducted as that mutual diffusion of silicon atoms in the silicon substrate 41 and iron atoms in the granular magnetic film 43 can be prevented by the SiO 2 diffusion preventing layer 42 formed between the silicon substrate 41 and the granular magnetic film 43 . While, the reason why Ms is increased in the solid line in FIG. 16 by annealing process at 800° C. for ten minutes is that an amount of the ferromagnetic α-Fe is not reduced.
FIG. 20 shows the XRD measurement result obtained after the comparative sample shown in FIG. 15 is annealed. According to this measurement result, only diffraction rays from a compound of iron and silicon appear as peaks. This may be considered such that the body-centered cubic (bcc) system iron (α-Fe), which exists in the granular magnetic film 53 as the magnetic grains 53 g before annealing, is combined with silicon atoms by annealing process to thus form silica iron. While, the reason why Ms is reduced in the broken line in FIG. 16 by annealing process at 800° C. for ten minutes is that an amount of the ferromagnetic α-Fe reduced.
(Change of Coercive Force)
FIG. 21 shows the result which ha been obtained by the experiment to confirm how coercive force of the granular magnetic film 43 serving a the magnetic recording medium shown in FIG. 14B is changed by annealing process. In FIG. 21, the abscissa indicates an annealing temperature (°C), and the ordinate indicates coercive force Hc (Oe).
As may be evident from FIG. 21, if the annealing temperature is increased higher, coercive force of the granular magnetic film 43 is increased in proportion. At the annealing temperature of 500° C. coercive force becomes 800 oersted (Oe). Here ten minutes is selected a the annealing time.
With the above, it has been appreciated that, if the diffusion preventing film interposed between the granular magnetic film and the silicon substrate, the magnetic recording medium having coercive force suitable for large reproducing output and high recording density can be achieved by annealing process.
In the case in which a film wherein magnetic fine grains such as nickel (Ni), cobalt (Co), or others are distributed into the SiO 2 film is used as the granular magnetic film, the nonmagnetic film interposed between the granular magnetic film and the silicon substrate can prevent the compound of fine grains of magnetic substance and silicon from being generated.
In any case, according to the magnetic recording medium shown in FIG. 14D, since both the diffusion preventing layer 42 and the granular magnetic film 43 are formed with the same SiO 2 and also the SiO 2 and the silicon substrate 41 may be tightly adhered to each other, film exfoliation because of thermal expansion does not occur even if they are annealed at high temperature in excess of 300° C.
Incidentally, the nonmagnetic film such as Si 3 N 4 , SiON, Cu, Cr or the like as well a SiO 2 may be used.
As discussed earlier, according to the eighth embodiment, since the nonmagnetic layer including no magnetic grains is formed between the silicon substrate and the nonmagnetic layer including magnetic grains and also the nonmagnetic layer including no magnetic grains therein is used as the diffusion preventing layer, mutual diffusion of silicon in the silicon substrate and magnetic grains by heat can be prevented by the diffusion preventing layer.
Therefore, since the compound of the magnetic substance and silicon is not generated, reduction of the magnetic substance is prevented, and the magnetic recording medium having high coercive force and enabling high recording density can be achieved. In addition, the granular magnetic layer excluding the magnetic fine grains and the diffusion preventing layer are formed with the same material, difference in thermal stress between the granular magnetic layer and the diffusion preventing layer can be eliminated, so that there is no possibility of film exfoliation. As a result, the stable layer structure can be attained.
Besides, since a product of the thickness of the silicon oxide layer including the magnetic fine grains and residual magnetization is set to be less than 100 Gauss•μm, the magnetic recording layer can be applied to the magnetoresistance head.
Furthermore, in the case in which any one of iron, cobalt, and nickel is included as the magnetic fine grains, the effect of the diffusion preventing layer becomes conspicuous since their atoms and silicon are easily combined with each other by annealing process.
(9) Explanation of a magnetic recording drive according to a ninth embodiment of the present invention:
With reference to FIG. 22, a magnetic recording drive in which the magnetic recording mediums according to the first to eighth embodiments are used selectively in the magnetic disk will be explained.
As shown in FIG. 22, a magnetic recording drive 45 comprises a magnetic disk 46 , a slider 47 having a MR head, and a spring arm 48 for supporting the slider 47 .
Referring to FIGS. 23A to 23 C, details of the magnetic recording medium and the magnetic head in the magnetic recording device will be explained. FIGS. 23A to 23 C are sectional views.
FIG. 23A shows a composite type MR head. An A portion denotes a reproducing head, and a B portion denotes a recording head. A soft magnetic layer 102 is used as a magnetic shield of the reproducing head and magnetic poles of the recording head commonly.
According to this magnetic recording device, since the magnetic recording mediums according to the above embodiments are used, high density recording, high reproducing output, and small noise can be achieved.
As shown in FIG. 23A, in the reproducing head portion, soft magnetic layers 101 , 102 serving as the magnetic shield are opposed to each other at a distance. The above MR element is placed in a gap between the magnetic recording medium 106 and the opposing portion 105 . Leakage magnetic field from the magnetic recording medium 106 can be detected directly by the MR element.
In addition, in the recording head portion, soft magnetic layers 102 , 104 serving as the magnetic poles are opposed to each other at a distance. A coil 103 for generating the magnetic flux which flows through the soft magnetic layers 102 , 104 is arranged in a gap between the soft magnetic layers 102 , 104 . Recording on the magnetic recording medium 106 is effected by generating the leakage magnetic field from the gap in the opposing portion 105 based on the magnetic flux.
FIG. 23B shows an in-gap type MR head having a flux guide. As shown in FIG. 23B, soft magnetic layers 111 , 114 serving as magnetic poles are placed opposedly at a distance. The MR element is put in the gap between a magnetic recording medium 116 and an opposing portion 115 A. A coil 113 for generating the magnetic flux passing through the soft magnetic layer 111 , 114 is formed in a gap between the soft magnetic substances 111 , 114 .
In order to avoid corrosion or direct contact to the magnetic recording medium, the MR element is placed in the inside of the magnetic head without protruding toward the opposing portion 115 of the magnetic recording medium 116 . A flux guide 112 a which is electrically isolated from the MR element and magnetically coupled with the MR element is protruded to the opposing portion 115 . Leakage magnetic field generated from the magnetic recording medium 116 enters into the flux guide 112 a, and is then detected by the MR element. Another flux guide 112 b which is also electrically isolated from the MR element and magnetically coupled with the MR element is provided at other end of the MR element, and leads the magnetic flux passed through the MR element to the soft magnetic layers 111 , 114 .
FIG. 23C show a yoke type MR head. As shown in FIG. 23C, soft magnetic layer 121 , 123 a and 123 b serving as magnetic poles are placed opposedly at a distance. A coil 122 for generating the magnetic flux passing through the soft magnetic layers 121 , 123 a and 123 b is formed in a gap between the soft magnetic layers 121 , 123 a and 123 b. The MR element is placed at the cut portion of the soft magnetic layers 123 a and 123 b in such a manner that it is electrically isolated from the soft magnetic layers 123 a and 123 b and also it is magnetically coupled with them. Recording on the magnetic recording medium 106 is effected by generating the leakage magnetic field from the gap in the opposing portion 124 by virtue of the magnetic flux which is generated by the coil 122 and passed through the soft magnetic layers 121 , 123 a and 123 b.
In the magnetic recording device shown in FIGS. 23A to 23 C, substrates on which the magnetic heads are formed, insulating films formed between the soft magnetic layers, etc. are omitted.
In addition, the magnetic recording medium according to the embodiments of the present invention may be used in not only the above magnetic recording drive but also various recording drives, each having a writing portion and a reading portion.
Furthermore, the above magnetic recording medium may also be used in the reproducing only magnetic recording drive. | The present invention relates to a magnetic recording medium for use in an external memory device of an information processing apparatus etc., and an object thereof is to reduce noise, achieve high coercive force, and use the substance as a magnetic recording medium for detecting signals in a magnetoresistance head. In the magnetic recording medium comprising the magnetic recording layer 25 including ferromagnetic grains 22 and a nonmagnetic substance 23 , the improvement in structure comprises that the ferromagnetic grains 22 are formed to have respectively an average grain diameter of 50 nm or less and not to be overlapped in the film thickness direction and to be isolated in the direction along a layer surface, and that a product of residual magnetization and a film thickness of the magnetic recording layer 25 is less than or equal to 150 Gauss•μm. | 8 |
FIELD OF THE INVENTION
The invention relates to airway clearance treatments. Specifically, the present invention is directed to a force-multiplying percussor and self-applicator system for airway clearance. A percussor is a medical device for supplying impulse forces to a patient's back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. A self-applicator is a strap that holds a percussor in a secure manner such that an individual can apply the percussor to their back without assistance from another person.
BACKGROUND OF THE INVENTION
A percussor is a medical device for supplying impulse forces to a patient's back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. The present invention is of a system of straps to allow a person to properly apply a percussor against his or her own back.
The type of percussor is based on the use of a solenoid in developing impulse forces for application to a patient's back or chest, A “solenoid”, as defined in the McGRAW-HILL, DICTIONARY OF SCIENTIFIC AND TECHNICAL TERMS, Fourth Edition, Sybil P. Parker, Editor in Chief, McGraw-Hill Book Company, New York, N.Y., 1989, is “a coil that surrounds a movable iron core which is pulled to a central position with respect to the coil when the coil is energized by sending current through it.”
An example of this type of percussor is described in U.S. Pat. No. 4,512,339 as a device which energizes a coil to develop an impulse force for application to a patient and utilizes a compressed spring to return the movable iron core to its rest position. The designs of percussors of this type are unnecessarily complicated and inflexible with respect to theft use in treating patients and the adjustment of the operating parameters of the devices.
The present invention avoids the complexities and inflexibilities of the prior art by utilizing a solenoid in a new and different way in generating impulse forces. The present invention utilizes the solenoid only for returning the movable iron core to its rest position. The patient-experienced impulse forces that result from the present invention are multiplied versions of the continuing force applied by a technician in using the invention.
By the nature of such a percussor and human physiology, it is extremely difficult for individual to self-apply a percussor to their own back. The present invention makes it possible for an individual to hold a percussor against his or her own back so as to properly apply the impacting force for the purpose of loosening and dislodging bronchial secretions in the lungs. The person can self-apply the percussor so as to not require the services of a technician in using the percussor.
Accordingly, there is a need for a self-applicator for an airway clearance device that addresses these needs. The present invention fulfills these needs and provides other related advantages.
SUMMARY OF THE INVENTION
The present invention is directed broadly to a medical device for supplying impulse forces to a patient's back or chest for the purpose of loosening and dislodging bronchial secretions in the lungs. More particularly, the invention is a force-multiplying percussor and self-applicator system for airway clearance. The force-multiplying percussor comprises an anvil, a hammer, a con, and a pulse generator. The self-applicator comprises first and second straps joined at their respective ends. The first strap overlays and is substantially co-extensive with the second strap. A pouch for holding the percussor is disposed between the first and second straps. The self-applicator also comprises a pair of handles with one each attached to one of the respective ends of the first and second straps.
In the percussor, the anvil is equipped with a force-receiving surface and a force-delivering surface which are rigidly connected together, the force-delivering surface being intended for contact with a patient's body. The hammer is also equipped with a force-receiving surface and a force-delivering surface, the hammer being oriented with respect to the anvil in such a way that the force-delivering surface of the hammer and the force receiving surface of the anvil are mechanically free to come together or move apart.
The coil forces the force-delivering surface of the hammer and the force-receiving surface of the anvil to separate when the solenoid is energized with an electrical current. The puke generator supplies repeated electrical current pukes to the coil which causes repeated force-multiplied impulse forces to be applied to a patient's body via the force-delivering surface of the anvil whenever the technician applies a continuing force to the force-receiving surface of the hammer.
In the self-applicator, the first strap is preferably longer than the second strap so as to define an open region between the two straps. The second strap has an application surface on one side. The application surface comprises a padded material and is configured so as to make physical contact with a user's back. The pouch is disposed in the open region. The pouch is attached to at least one and preferably both of the straps.
The pouch comprises a closure mechanism. The closure mechanism is configured so as to securely hold the percussor. The closure mechanism comprises adjustable hook and loop straps configured so as to accommodate percussors of varying sizes.
At least one of the pair of handles is attached to one of the ends of the first and second straps by an adjustable length harness. The other of the pair of handles is attached to the other of the ends of the first and second straps by a fixed length harness.
A method for using the force-multiplying percussor and self-applicator system begins with the step of inserting the percussor into the pouch. The percussor is positioned in the pouch such that an anvil is oriented toward the second strap. A user then grasps each of the pair of handles in his/her hands. The user then self-applies the application surface of the second strap to his/her back. The percussor is turned on such that a force delivering surface of the anvil contacts the user's back through the application surface.
The method further comprises the step of closing the closure mechanism on the pouch so as to securely hold the percussor in the pouch. The method also comprises the step of adjusting the length of the adjustable length harness on one of the pair of handles so that the user can comfortably perform the self-applying step.
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 DRAWINGS
The accompanying drawings illustrate the invention. In such drawings:
FIG. 1 is a perspective view of a first embodiment of the percussor of the present invention;
FIG. 2 is a sectional view taken along line 2 - 2 of FIG. 1 with the hammer shown in a neutral position relative to the anvil;
FIG. 3 is a sectional view taken along line 2 - 2 of FIG. 1 with the hammer shown fully-withdrawn from contact with the anvil;
FIG. 4 is a perspective view of a second embodiment of the percussor of the present invention;
FIG. 5 is a sectional view taken along line 5 - 5 of FIG. 4 with the hammer shown in a neutral position relative to the anvil;
FIG. 6 is a sectional view taken along line 5 - 5 of FIG. 4 with the hammer shown in contact with the anvil;
FIG. 7 is a schematic drawing illustrating the inputs and outputs of the pulse generator which supplies the driving current for the percussor;
FIG. 8 is an elevated perspective view of the self-applicator of the present invention;
FIG. 9 is an elevated perspective view of the self-applicator of the present invention illustrating insertion of a percussor;
FIG. 10 is an exploded perspective view of the self-applicator of the present invention;
FIG. 11 is an environmental view of the force multiplying percussor and self-applicator system of the present invention being self-applied by a user;
FIG. 12 is a close-up cut-away view of the force multiplying percussor and self-applicator system of the present invention being self-applied by a user;
FIG. 13 is a perspective view of a particularly preferred embodiment of a percussor of the present invention;
FIG. 14 is a cut-away view of the particularly preferred embodiment of the percussor depicted in FIG. 13 ;
FIG. 15 is a partially dis-assembled view of the particularly preferred embodiment of the percussor of FIG. 14 ;
FIG. 16 is a cross-sectional view of the front wall of the particularly preferred embodiment of the percussor of FIG. 14 ;
FIG. 16 a is an end view of the front wall of the particularly preferred embodiment of the percussor of FIG. 14 ;
FIG. 17 is a side view of the shaft and plunger of the particularly preferred embodiment of the percussor of FIG. 14 ; and
FIG. 18 is a cross-sectional view of the rear support bearing of the particularly preferred embodiment of the percussor of FIG. 14 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to a force-multiplying percussor and self-applicator system for airway clearance, the system being referred to generally by reference numeral 20 . The system 20 comprises a percussor 22 and a self-applicator 24 , all of which are illustrated in FIGS. 1-12 .
A first embodiment of the percussor 22 is shown in FIGS. 1-3 . The percussor 22 of the present invention consists of a hammer 26 and an anvil 28 oriented with respect to one another such that the hammer 28 may impact the anvil 28 . The percussor 22 is configured to be placed on the back or chest of a patient with the anvil 28 in contact with the patient's body. Typically, a user holds the percussor 22 in place by gripping the hammer 26 with one hand, palm on top, and then turns on the power. The force continually applied by the user to the hammer 26 is converted by the percussor 22 into repeated force-multiplied impulses in which the force associated with each impulse is significantly greater than the force being applied by the user on a continuing basis.
The details of the percussor 22 design are shown in the sectional views of FIGS. 2 and 3 . The hammer 26 consists of a plastic structural member 30 attached to guiding member 32 . Guiding member 32 may be either metal or plastic and attaches to structural member 30 utilizing mating threaded regions (not shown). Coil 34 is embedded in structural member 30 as shown (assuming structural member 30 is a plastic material).
The anvil 28 consists of ring 36 and platen 38 connected together by cylindrical guiding member 40 . Ring 36 has a rectangular cross-section and is made of a magnetic material such as iron. Guiding member 40 attaches to ring 36 by a press fit. Platen 38 is attached to guiding member 40 by means of a machine screw (not shown). The hammer 26 has a force receiving surface 42 and a force delivering surface 44 . The anvil 28 also has a force receiving surface 46 and a force delivering surface 48 .
If there is no current flowing through coil 34 , hammer 26 is free to slide back and forth along guiding member 40 subject only to the constraints imposed by the combination of structural member 30 and guiding member 32 . Current flowing through coil 34 generates a magnetic field which exerts a force on ring 36 causing hammer 26 and anvil 28 to assume an extended position, i.e., the relative positions shown in FIG. 3 .
In operation, a user places the force delivering surface 48 of the anvil 28 against a patient's chest or back in the gentlest possible way and coil 34 is energized by a series of current pukes. When the coil 34 is energized, hammer 26 and anvil 28 will assume the extended position shown in FIG. 3 and remain in that extended position for as long as the coil 34 is energized and the user does not apply a force to force-receiving surface 42 of the hammer 26 .
Now assume that the user begins to apply a force (with their hand) to force-receiving surface 42 of the hammer 26 while the coil 34 is energized with a current puke. Nothing happens because the magnetic force from the energized coil 34 holding hammer 26 and anvil 28 in the extended position is greater than the force applied by the user.
When the current puke to the coil 34 ends, the magnetic force holding the hammer 26 and anvil 28 in the extended position ends and any opposition to the force applied by the user to the force receiving surface 42 of the hammer 26 disappears. The force-delivering surface 44 of the hammer 26 then strikes the force-receiving surface 46 of the anvil 28 thereby delivering a considerably greater force to platen 38 than simply the force applied by the user's hand alone. The force delivering surface 48 of the anvil 28 translates the impact from the hammer 26 against the anvil 28 to the patient's chest or back with which it is in contact. The process repeats with each current puke supplied to coil 34 .
The work expended by the user is the product F 1 d h , of the force F 1 applied by the user to the force receiving surface 42 of the hammer 26 and the distance d h traveled by the hammer 26 before striking the anvil 28 . The user's work is converted into kinetic energy of the hammer 26 . This kinetic energy is dissipated when the hammer 26 strikes the anvil 28 and the anvil 28 depresses the patient's flesh. The kinetic energy is converted into potential energy associated with the depression of the patient's flesh and heat. The user's work is balanced by the work F p d p expended by the patient's body which resists the anvil 28 with a force F p over a distance d p . Thus, the effective force applied by the anvil 28 to the patient's body is given by F p =(d h /d p )F 1 .
The ratio (d h /d p ) of the distance traveled by the hammer (d h ) to the distance traveled by the patient's flesh (d p ) is typically greater than three and consequently the percussor 22 described herein typically has a force-multiplying effect. For example, a user's force of 10 lbs is typically experienced as a force of 30 lbs or more by a patient.
A second embodiment of the percussor 22 is shown in FIGS. 4-6 . It also consists of a hammer 26 and an anvil 28 . The design details for the second embodiment are shown in the sectional views of FIGS. 5 and 6 . The hammer 26 consists of a plastic structural body 50 in which is embedded a core 52 made of a magnetic material such as iron. The anvil 28 consists of a plastic body 54 in which is embedded coil 34 which surrounds core 52 when the hammer 26 is inserted into the anvil 28 .
As in the first embodiment, the hammer 26 has a force receiving surface 42 and a force delivering surface 44 , and the anvil 28 also has a force receiving surface 46 and a force delivering surface 48 . If there is no current flowing through the coil 34 , the hammer 26 is free to slide back and forth within the anvil 28 but limited in range by three pins (not shown) anchored into the curved wail of the anvil 28 and terminating in three vertical grooves (not shown) spaced 120 degrees apart in hammer 26 . When a current flows through the coil 34 it generates a magnetic field which exerts a force on core 52 causing hammer 26 and anvil 28 to assume the positions shown in FIG. 5 .
In operation, the percussor 22 is paced against the back or chest of a patient with the force delivering surface 48 of the anvil 28 in contact with the patient's body. The user holds the percussor 22 in place by gripping the force receiving surface 42 of the hammer 26 with one hand, palm on top, and then turns on the power. As described above, the force continually applied by the user to the force receiving surface 42 of the hammer 26 is converted into repeated impacts of force on the patient's body through the force delivering surface 48 of the anvil 28 as current impulses pass through the coil 34 . Each time the current impulse through the coil 34 is ceased, the force delivering surface 44 of the hammer 26 impacts the force receiving surface 46 of the anvil 28 . Each such impact delivers the force through the anvil 28 to the force delivering surface 48 . The force associated with each impulse is significantly greater than the force being applied by the user to the force receiving surface 42 of the hammer 26 on a continuing basis.
Let us again assume that a user places the percussor 22 against a patient's back in the gentlest possible way and coil 34 is energized by a series of current pukes. Hammer 26 and anvil 28 will assume the positions shown in FIG. 5 and remain in those positions for as long as the technician does not apply a force to force-receiving surface 42 . Again assume that the technician begins to apply a force to force-receiving surface 42 while the coil 34 is energized with a current puke. Nothing happens because the magnetic force holding hammer 26 and anvil 28 in the relative positions of FIG. 5 is typically greater than any force that can be manually applied by a user.
When the current puke ends, the magnetic force opposing the force applied by the user disappears and the force-delivering surface 44 of the hammer 26 strikes the force-receiving surface 46 of the anvil 28 as shown in FIG. 6 . The hammer 26 thereby delivers a considerably greater force to the patient's back with which the anvil 28 it is in contact, as discussed above. As long as the user maintains a force on the hammer 26 , the impacting process repeats with each current puke supplied to coil 34 .
A schematic of the puke generator required to drive the coil 34 is shown in FIG. 7 . It preferably operates with standard 120 V AC input power and has means for controlling the frequency and amplitude, i.e., widths and rate of repetition, of the output pukes.
The self-applicator 24 consists of two substantially co-extensive straps having a pouch configured to accept and securely retain the percussor 22 . FIGS. 8 through 10 illustrate the self-applicator 24 along with its various components.
The self-applicator 24 has a pair of straps 56 , 58 being substantially co-extensive with one overlaying the other. The respective ends of the straps 56 a , 58 a and 56 b , 58 b are stitched 60 together or joined by any securing means know to those skilled in the art. One of the straps 56 is preferably slightly longer that the other strap 58 such that when the ends of the first strap 56 a , 56 b are joined to the ends of the second strap 58 a , 58 b , there is an open area 62 between the two straps 56 , 58 . Preferably, the stitching 60 or other securing means is applied a second time 60 a for added securement.
A pouch 64 is disposed in the open area 62 between the straps 56 , 58 . The pouch 64 may be in the form of a U-shaped pocket having a bottom 66 , upright sides 68 a , 68 b and an open top 70 . The pouch 64 in configured and designed to accept the percussor 22 through the open top 70 and securely retain the percussor 22 therein. Front and back edges 72 a , 72 b of the pouch 64 are in contact with inside surfaces 56 c , 58 c of the straps 56 , 58 . At least one of the front and back edges 72 a , 72 b are attached to the inside surfaces 56 c , 58 c so as to securely retain the pouch 64 in the open area 62 . Preferably, both front and back edges 72 a , 72 b are attached to the inside surfaces 56 c , 58 c.
The pouch 64 also includes a closure mechanism 74 designed to cover the open top 70 . The closure mechanism 74 preferably comprises a pair of adjustable hook and loop straps 74 a , 74 b . The straps 74 a , 74 b preferably have essentially their entire mating surfaces covered by hook and loop material, i.e., VELCRO®, whereby the respective straps 74 a , 74 b can be adhered to each other at any point along their length. The closure mechanism 74 can also comprise snaps, buttons, a zipper, or other commonly known methods of closure.
A pair of handles 76 , 78 are secured to the respective ends 56 a / 58 a , 56 b / 58 b of the straps 56 , 58 . The ends 76 a , 78 a of the handles 76 , 78 are preferably secured between the ends 56 a / 58 a , 56 b / 58 b of the straps 56 , 58 when they are stitched 60 together. At least one of the straps 78 includes an adjustable length harness 80 so that the length of the handle 78 may be changed to accommodate users of different sizes. Each of the handles 76 , 78 include respective grips 76 b , 78 b for a user 82 to grasp in each of his/her hands 84 .
The second strap 58 includes an applicator surface 58 d that is configured to contact the back 86 of a user 82 when the self-applicator system 20 is being applied. The application surface 58 d is aligned with the inside surface 58 c at the point where the pouch 64 is disposed or secured. The applicator surface 58 d preferably comprises a soft, comfortable material that will not irritate a user's skin and can easily and smoothly move during use. The applicator surface 58 d may even include padding to provide comfort to the user.
The method of using the system 20 begins with arranging the self-applicator 24 on a surface such that the pouch 64 is oriented with the open top 70 pointing upwards. A user then inserts the percussor 22 into the open top 70 of the pouch 64 . The percussor 22 is positioned in the pouch 64 such that the anvil 28 on the percussor 22 is pointed toward the inside surface 58 c of the second strap 58 . The closure mechanism 74 is secured around the percussor 22 so as to securely retain the percussor 22 in the pouch 64 in a manner that does not allow rotation, revolution or other similar movements during use.
If necessary, the user 82 can adjust the length of the adjustable length harness 80 to make the system 20 more comfortable to use. The user 82 then grasps each of the handles 76 , 78 in his or her hands 84 and self-applies the application surface 58 d to his/her back 86 . As illustrated in FIGS. 11 and 12 , the self-applicator 24 spans the user's back 86 with the user's hand 84 in front of his/her body, pulling the handles 76 , 78 forward to apply force to the force receiving surface 42 of the hammer 26 and resultant pressure to the back 86 . The user 82 then turns on the percussor 22 with the results as described above.
By moving ones hand 84 up/down and side/side, the user 82 can self-apply the percussor 22 to almost any area of his/her back 86 . By aligning the anvil 28 of the percussor 22 with the application surface 58 d , the user is able to keep the anvil 28 in contact with the user's back 86 without the need for a treatment technician or the aid of any other person. The user can also more easily self-apply the percussor 22 to those parts of his/her back 86 that are most beneficial for the loosening or dislodging of bronchial secretions in the lungs, rather than try and describe to another person where to apply the percussor 22 .
Except for the applicator surface 58 d , described above, the self-applicator 24 and its various components are made from a sturdy, durable material such as nylon or similar polymer material. The goal in selecting a material is to make sure that the self-applicator 24 is comfortable for the user while still being durable enough to withstand the stresses of self-application and the movement of the percussor 22 . The grips 76 b , 78 b preferably comprise a soft, durable polymer material such as polyurethane, latex, or similar materials, molded to form hand grips 76 b , 78 b.
FIGS. 13 through 18 illustrate a particularly preferred embodiment of the percussor 90 of the present invention. From the outside, the percussor 90 consists of a rear cover or hand hold 92 , an anvil 94 and an intervening thermal shell 96 . Inside of the thermal shell 96 is a housing 98 , which encloses a solenoid 100 . The solenoid 100 comprises an internal shell 102 containing a central shaft 104 upon which is mounted a plunger 106 . The plunger 106 may be shaped as a cylinder with recessed cavities at its upper 106 a and lower 106 b ends. The plunger 106 may also be presented in other shapes so as to conform to adjacent parts as described below. The plunger 106 is made from magnetic material as the ring 36 or core 52 described above. A coil 108 surrounds the shaft 104 and plunger 106 and exerts magnetic forces thereon when energized.
The bottom of the shell 102 contains a front wall 110 that includes an upward extending base 112 that generally matches the shape of the recess in the lower end 106 b of the plunger 106 . The front wall 110 also includes a central opening 114 through which the shaft 104 extends. One end 104 b of the shaft 104 protrudes through the front wall 110 and is connected to the anvil 94 by a screw 116 or similar securement mechanism. As the shaft 104 slides through the shell 102 , the anvil 94 follows.
The top of the shell 102 contains a rear support bearing 118 secured thereto. The rear support bearing 118 has a lower surface that generally conforms to the shape of the recess of the upper end 106 a of the plunger 106 . The rear support bearing 118 also includes a central opening 120 through which the shaft 104 extends. The central opening 114 of the front wall 110 and the central opening 120 of the rear support bearing 118 cooperate to keep the shaft 104 in straight line, oscillating movement through the shell 102 .
The rear cover 92 provides a hand hold for a user to grasp the percussor 90 . In the terms of the previously described embodiment, the upper surface of the rear cover 92 provides a force receiving surface 122 of the hammer 124 . The force delivering surface 126 of the hammer 124 is located at the bottom of the housing 98 . The anvil 94 includes a force receiving surface 128 that receive impacts from the force delivering surface 126 of the hammer 124 . The anvil 94 also includes a force delivering surface 130 . These surfaces 122 , 126 , 128 and 130 interact as described above in the earlier embodiment.
As shown in FIG. 16 a , the front wall 110 includes set screw openings 132 around its perimeter. These set screw openings 132 are configured to receive set screws through the wall of the shell 102 so as to secure the front wall 110 thereto. The upper surface of the upward extending base 112 includes bumpers 134 . The bumpers 134 are configured to cushion the impact between the plunger 106 and the base 112 when the coil 108 is energized. This cushioning is only intended to make the impact less jarring or noise generating—it does not lessen the force of any impact.
The thermal shell 96 is configured to insulate the user against heat generating by the oscillations of the solenoid 100 when the percussor 90 is in use. The thermal shell 96 provides an air gap 136 between the thermal shell 96 and the housing 98 . In addition, the rear cover 92 houses the pulse generator 138 as discussed above, as well as a cooling fan 140 . The pulse generator 138 is connected to the coil 108 . As the pulse generator 138 energizes the coil 108 , electricity is also supplied to the cooling fan 140 , which draws air through the housing 98 and out the exhaust vents 142 to provide additional cooling.
The percussor 90 of this alternate embodiment may also be used with the self-applicator 24 . The percussor 90 may fit within the pouch 64 as described above.
Although the system 20 has been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. The above-described disclosure is not intended to limit the scope of the invention. Accordingly, the scope of the present invention is determined only by the following claims. | An airway clearance combines a force multiplying percussor and a self-applicator assembly. The percussor has an anvil, a hammer, a coil, and a pulse generator. The anvil has a force receiving surface and a force delivering surface. The hammer also has a force-receiving surface and a force-delivering surface, and is attached to the anvil such that the hammer's force delivering surface and the anvil's force receiving surface are mechanically free to come together or move apart. When energized with an electrical current, the coil forces the hammer's force delivering surface and the anvil's force receiving surface to separate. The pulse generator supplies pulses of electrical current to the coil. | 0 |
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