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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to fuel filters employed in connection with internal combustion engines. More particularly, the present invention relates to replaceable fuel filter cartridges for removing foreign particles and/or separating water from the fuel supply system of an internal combustion engine.
[0003] 2. Description of the Related Art
[0004] Fuel filter systems to which the invention relates commonly employ a disposable filter cartridge that is replaced at pre-established intervals of filter usage. The replaceable cartridge is conventionally secured to a base that defines inlet and outlet connections between the cartridge and the fuel supply system. Numerous retention systems have been employed for securing the filter cartridge to the base and allowing removal of the cartridge for replacement purposes.
[0005] In practice, filter cartridge requirements may vary depending upon: the type and make of the internal combustion engine; the specific application for which the engine is employed; the climate in which the engine is operated; and/or regional characteristics as to the quality of the fuel supply. Filter cartridges suitable for replacement in a particular filtration system, commonly vary as to capacity, fluid compatibility and filter media qualities.
[0006] One of the recurring problems in assuring filtration system performance is encountered in connection with replacement of the filter cartridge. It is imperative that the replacement cartridge be compatible with the filtering requirements for the fuel system. It is common for filter cartridges to have a generally similar exterior configuration regardless of performance. As a result, a replacement filter cartridge may dimensionally conform to the base of a given fuel filter assembly, and not comply with the applicable specifications for the fuel system and thereby jeopardize the integrity of the fuel filtering system. Replacement with an incompatible filter cartridge can have very serious consequences for the operation of the internal combustion engine and may also be unnecessarily more expensive than less costly cartridges which are fully suitable. In practice, replacement cartridges may be so similar in overall configuration that the owner of the vehicle and/or the maintenance technician servicing the internal combustion engine may unknowingly jeopardize the integrity of the filtering system by replacement with a wholly unsuitable cartridge even though the unsuitable cartridge at least cursorily appears to be suitable. There are also, of course, instances where inferior or improper replacement filter cartridges are intentionally installed without the knowledge of the owner of the operator of the vehicle.
[0007] For many applications, it is also desirable that a cartridge be mounted to the base at a specific angular orientation so that warnings, directions and markings affixed to the cartridge may be properly positioned to ensure visibility and maximize the chances of successful information dissemination. For other applications, it is desirable that the cartridge be locked in position relative to the base such that the cartridge may not rotate with relation to the base.
[0008] U.S. Pat. No. 5,035,797, which is assigned to the assignee of the present invention, discloses a fuel filter assembly in which a base mounts to the vehicle and a disposable filter cartridge is suspended from the base. The cartridge is retained to the base by a threaded collar that engages against a protruding roll seam structure at the periphery of the cartridge housing. The cartridge is replaced by loosening the threaded collar and dismounting the filter cartridge. A key system is disclosed in which keys axially project from the base through corresponding slots in the end cap of the filter cartridge housing. The dimensions and location of the axially projecting keys ensure compatibility by interfering with mounting and sealing of incompatible cartridges lacking the correct slot configuration. The keys interlock with the slots to mount the cartridge at a fixed angular relationship to the base.
[0009] U.S. Pat. No. 5,837,137, which is assigned to the assignee of the present invention, discloses a similarly configured fuel filtration assembly (e.g., the cartridge is retained to the base by a threaded collar) incorporating an alternative location and key system. Protrusions from a receiving surface of the base are received in corresponding dimples in the opposing end surface of the cartridge to lock the cartridge at a fixed angular position relative to the base. The protrusions interfere with the mounting and sealing of a non-compatible cartridge having an incompatible pattern of dimples.
[0010] A further variation on ensuring compatibility in fuel filtration assemblies similar to those described above is disclosed in U.S. Pat. No. 5,766,463, which is assigned to the assignee of the present invention. The disclosed fuel filter cartridge is formed from a pair of shell sections joined along a roll seam to form the retaining shoulder. The generally cylindrical upper portion of the filter cartridge is received within the base. A plurality of arcuate protrusions radially project from the cylindrical upper portion of the cartridge to be received in compatible tracks in the base. The protrusions are disclosed as part of a key code system including the key/slot system described in the '797 patent. A keying system that relies on protrusions from the received portion of the cartridge housing may permit defeat of the keying system by allowing a cartridge without the protrusions to be received in the keyed base without interference.
[0011] An alternative filter cartridge mounting system is disclosed in U.S. Pat. No. 6,187,188, also assigned to the assignee of the present invention. The roll seam at the junction of the cartridge housing sections is radially outwardly displaced to form a plurality of retention tabs. The base includes a fixed retaining structure comprising a retaining lip defining a plurality of axial slots in communication with retaining channel portions above the retaining lip. The axial slots are located and dimensioned to be complementary to the retaining tabs of the filter cartridge. The filter cartridge is retained to the base by axially aligning the tabs with the slots and upwardly displacing the cartridge into the receptacle of the base. The cartridge is then rotated so that the tabs are engaged within the retaining channel portions. The '188 patent discloses that compatibility of the cartridge with the base may be ensured by providing the received portion of the cartridge with arcuate slots to accommodate keys axially projecting from the base as disclosed in the '797 patent. Alternatively, the received portion of the cartridge may be provided with radial protrusions such as those disclosed in the '463 patent. Tracks in the base for receiving the protrusions must be L-shaped (have an axial portion and a radial portion) to accommodate rotation of the cartridge relative to the base.
[0012] Ensuring filter cartridge compatibility is an issue of continuing concern in the art. While the approaches to ensuring filter cartridge compatibility described in the '797, '137, '463, and '188 patents represent significant advances over the prior art, further improvements in effectiveness and efficiency are possible. For example, keys projecting from the base that require openings in the filter cartridge compromise the sealed integrity of the filtration system. Keying arrangements that restrict the cartridge to a fixed angular position relative to the base are incompatible with filter assemblies that require rotation of the cartridge relative to the base. The L-shaped tracks disclosed in the '188 patent may be difficult to produce, thereby increasing the cost of filter assemblies.
[0013] There is an ongoing need in the art for a filter assembly that prevents installation of incompatible filter cartridges. Ideally, a filter cartridge compatible with such a key system may be employed with a filter assembly in which the cartridge is retained to the base by a collar and filter assemblies in which the cartridge is rotated to engage radially projecting tabs in a retainer fixedly extending from the base.
SUMMARY OF THE INVENTION
[0014] A first aspect of the present invention pertains to inward and outward displacement of a roll seam at the junction of housing sections of a filter cartridge to provide components of a cartridge compatibility matrix. Portions of the roll seam are radially outwardly offset to form retention tabs. Further portions of the roll seam are radially inwardly displaced relative to the remainder of the roll seam. In one embodiment, the cartridge housing is substantially symmetric about a central axis, and the retention tabs are equiangularly spaced about the axis. The tabs are also substantially equivalent in angular extent and radial displacement, i.e., the tabs have the same general configuration. Consequently, the roll seam includes three substantially equal length portions extending between the retention tabs. One or more of these roll seam portions may include a segment that is inwardly displaced with respect to the central axis. The receptacle of a compatible base is provided with structures permitting reception and sealing of a cartridge with a complementary pattern of retention tabs and inward displaced segments. A non-compatible cartridge, for example a cartridge with a similar arrangement of retention tabs but lacking the requisite inwardly displaced segments of the roll seam, is prevented from mating with the base.
[0015] In a base with a fixed retainer where the retention tabs are axially received through slots and the cartridge secured to the base by rotation relative to the base, compatibility is ensured by inward protrusions on the retainer lip. The inward protrusions of the retaining lip correspond to the inwardly displaced segments of the roll seam and allow axial reception of the roll seam through the retaining lip. The roll seam of an incompatible filter cartridge will lack the correct arrangement of inwardly displaced portions of the roll seam will be prevented from axial reception into the base. In one cartridge compatibility matrix, the roll seam includes three equiangularly spaced retention tabs and three equiangularly spaced inwardly displaced segments of the roll seam. Alternatively, the inwardly displaced portions may be non-symmetrical to ensure a particular installed orientation of the cartridge relative to the base.
[0016] In addition, the filter cartridge may also comprise at least one outward protrusion from the side wall of that portion of the cartridge received in the base. Rather than an L shaped track in the base receptacle, a ring at the entrance to the receptacle defines axial openings compatible with the protrusions on the cartridge. Together, the configuration of the roll seam and the received portion of the cartridge may be incorporated into multiple levels of keying for cartridge identification, cartridge positioning and quality control purposes.
[0017] Another aspect of the present invention relates to a filter assembly where a cartridge of the present invention is retained to a base by a collar. An annular lip of the base axially protrudes into a space defined between the roll seam and the received portion of the filter cartridge. The configuration of this space is complementary with the configuration of the roll seam, e.g., the retention tabs increase the radial dimension of the space and the inwardly displaced segments of the roll seam decrease the radial dimension of the space. The axially protruding lip of the base is provided with outward protrusions complementary with the retention tabs and locations where lip material is removed to accommodate inwardly displaced segments of the roll seam.
[0018] An object of the present invention is to provide a new and improved filter cartridge compatibility matrix.
[0019] Another object of the present invention is to provide a new and improved filter cartridge structure that ensures compatibility in filter assemblies having fixed and movable cartridge-retention systems.
[0020] A further object of the present invention is to provide a new and improved filter assembly in which compatibility protection cannot be defeated by omission of the compatibility matrix structure from the cartridge.
[0021] Other objects and advantages of the invention will become apparent from the drawings and the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
[0023] [0023]FIG. 1 is a vertical sectional view, partly broken away, of a fuel filter cartridge incorporating a compatibility matrix exemplary of several aspects of the present invention;
[0024] [0024]FIG. 2 is a top plan view of the filter cartridge of FIG. 1;
[0025] [0025]FIG. 3 is an enlarged view of an inwardly displaced segment of the roll seam of the filter cartridge of FIG. 2;
[0026] [0026]FIG. 4 is an enlarged sectional view through the roll seam at the left side of the filter cartridge of FIG. 1;
[0027] [0027]FIG. 5 is an enlarged portion of the filter cartridge shown in FIG. 2 illustrating a retention tab formed from an outward deformation of the roll seam;
[0028] [0028]FIG. 6 is a front view of a portion of a first filter base component configured to receive the filter cartridge of FIG. 1;
[0029] [0029]FIG. 7 is a side view of the filter base component of FIG. 6;
[0030] [0030]FIG. 8 is a top view of the filter base component of FIG. 6;
[0031] [0031]FIG. 9 is a sectional view of the filter base component of FIG. 6, taken along line 9 - 9 thereof;
[0032] [0032]FIG. 10 is a bottom view, partly in phantom, of the filter base component of FIG. 6;
[0033] [0033]FIG. 11 is a sectional view of the filter base component of FIG. 6, taken along line 11 - 11 thereof;
[0034] [0034]FIG. 12 is a side view of a second filter base component configured to receive the filter cartridge of FIG. 1;
[0035] [0035]FIG. 13 is a bottom view of the filter base component of FIG. 12;
[0036] [0036]FIG. 14 is bottom view, partly in phantom, of a retaining collar for retaining the filter cartridge of FIG. 1 to the base component of FIGS. 12 and 13; and
[0037] [0037]FIG. 15 is a sectional view of the collar of FIG. 14, taken along line 15 - 15 thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Preferred embodiments of a filter cartridge illustrating several aspects of the present invention will now be described with particular reference to FIGS. 1 - 5 . A first embodiment of a filter base component compatible with the cartridge of FIGS. 1 - 5 is shown in FIGS. 6 - 11 . A second embodiment of a filter base component compatible with the cartridge of FIGS. 1 - 5 is shown in FIGS. 12 - 15 .
[0039] [0039]FIG. 1 is a sectional view through an exemplary filter cartridge 10 comprising a first housing section 12 joined to a second housing section 14 along a peripheral roll seam 16 . FIG. 4 illustrates an enlarged sectional view through the roll seam 16 on the left hand side of FIG. 1. The sheet metal of the respective housing sections which forms the roll seam is shown as dotted lines to the left and right of the filter cartridge 10 adjacent the roll seam in FIG. 1. The sheet metal extending from the housing first section 12 extends radially beyond the sheet metal of extending from the housing second section 14 . When rolled together to form the roll seam shown in FIG. 4, the extended radial length of the sheet metal of the housing first section 12 is rolled under and overlaps the sheet metal of the housing second section 14 . The rolled, overlapping sheet metal is then crimped to form the roll seam in a manner known in the art. A U-shaped bend in the housing first section 12 inwardly of the roll seam defines a space 20 between the roll seam and the housing first section 12 . This space 20 allows access to the interior of the roll seam 16 during seam formation and for the purposes of deformation as will be discussed below.
[0040] The filter cartridge 10 has an overall general configuration and functionality that is well understood by those of skill in the art. A filter element 18 is supported within the filter cartridge. A grommet 30 surrounds an axial opening 32 in the housing first section 12 that receives coaxial conduits (not shown) for delivery of unfiltered fluid and retrieval of filtered fluid from the filter cartridge 10 . The housing second section 14 may be provided with a drain cock 60 for removal of water that may accumulate in a sump 15 defined by the lower portion of the housing second section 14 .
[0041] [0041]FIG. 2 is a top view of the filter cartridge of FIG. 1. The roll seam 16 circumscribes the filter cartridge 10 radially separated from the housing first section 12 to define an annular space 20 . The roll seam 16 includes three portions that are radially outwardly displaced relative to the central axis A of the cartridge to form retention tabs 24 . The retention tabs 24 are illustrated as being equiangularly arranged on the circumference of the roll seam and of equal angular extent and radial displacement. Three roll seam portions 23 extend between the retention tabs 24 . In the illustrated embodiment, each of these portions 23 of the roll seam include a radially inwardly displaced segment 22 . The inwardly displaced segments 22 provide one variable for use in conjunction with a cartridge compatibility matrix. The inwardly displaced segments 22 of the roll seam 16 on the exemplary filter cartridge 10 are diametrically opposed to each retention tab 24 .
[0042] The inward and outward displacement of the roll seam relative to its generally circular shape result in a serpentine configuration. This complex shape is advantageously located at the radial outer periphery of the filter cartridge. As will be discussed in greater detail below, a compatibility matrix including a serpentine, or convoluted outer periphery of the filter cartridge presents unique opportunities for blocking reception of cartridges omitting portions of the compatibility matrix. Further, inward and outward displacement of the roll seam 16 relative to the central axis A of the cartridge defines an annular space 20 having a variable radial dimension when measured perpendicular to the cartridge axis A, as best seen in FIG. 2. The shape of the annular space 20 may be used as part of a cartridge compatibility matrix when the cartridge 10 is mounted to a base including the component shown in FIGS. 12 and 13 by the collar shown in FIGS. 14 and 15. In accordance with a further aspect of the present invention, the outer profile of the roll seam 16 is used as a constituent of a cartridge compatibility matrix when the cartridge 10 is mounted to a base including the component shown in FIGS. 6 - 11 .
[0043] [0043]FIG. 3 illustrates an enlarged view of an inwardly displaced segment 22 of the roll seam 16 . In the illustrated embodiment, the inward displacement of the roll seam is in the form of an arc having a radius of curvature of approximately 2.5″ and a center of curvature located outside the roll seam 16 . The inward deformation displaces the roll seam 16 inwardly from its normal radius of curvature 17 (illustrated by the dashed line in FIG. 3) by a distance in the range of 0.02″ to 0.05″ at the center of the deformation. The inwardly displaced segment has a length of approximately 0.5″ measured along the circumference of the roll seam.
[0044] [0044]FIG. 5 is an enlarged portion of FIG. 2 illustrating the outward displacement of the roll seam 16 to form a retention tab 24 . The roll seam is radially outwardly displaced by a distance of approximately 0.08″ relative to adjacent portions of the roll seam or a distance approximately equivalent to the radial thickness of the roll seam 16 . Each retention tab 24 of the illustrated embodiment maintains its maximum outward displacement (of approximately one roll seam thickness) for approximately 0.5″. It will be appreciated that the roll seam 16 includes transitional portions 24 a adjacent either end of the retention tabs. The roll seam 16 between the retention tabs 24 (including their transitional portions 24 a ) and the inwardly displaced segments 22 maintain a substantially constant radius of curvature centered on the cartridge axis A.
[0045] FIGS. 6 - 11 illustrate one component of a first embodiment of a filter base configured to mount the filter illustrated in FIGS. 1 - 5 . The illustrated component 40 of a filter base is a molded member with integrally extending bracket portions 42 . The bracket portions 42 are configured to receive a reinforcing metal sleeve (not shown) through which an attachment bolt (not shown) retains the filter base to a support structure (not shown). Below the bracket portions, the illustrated base component 40 comprises a generally cylindrical wall 46 that defines a receptacle 47 for axially receiving the filter cartridge housing first section 12 . An axial central conduit 48 of the base component 40 is received and sealingly engaged by a grommet 30 of an installed filter cartridge 10 . The cylindrical wall 46 flares to include a fixed integral retainer 44 . The retainer 44 comprises three axial slots 51 complementary to the radially projecting retention tabs 24 on the cartridge 10 . The axial slots 51 communicate with retaining channel portions 43 partially defined by a retaining lip upper surface comprising a ramp 52 and a seat 54 .
[0046] The first housing section 12 of the filter cartridge 10 is axially inserted into the receptacle 47 until the retaining tabs 24 are aligned with the retaining channel portions 49 . The cartridge 10 is then rotated clockwise relative to the base. During rotation, the retaining tabs ride up the ramps 52 and over a raised portion of the retaining lip to seats 54 defined by the retaining lip upper surface. A resilient radial extension 34 of the cartridge grommet 30 biases the cartridge 10 away from the base component 40 so that the seated retention tabs 24 resist unintended counterclockwise rotation of the cartridge 10 relative to the base.
[0047] In accordance with an aspect of the present invention, the retainer 44 defines lip portions 72 having an inward-facing profile including radially inward projecting protrusions 56 corresponding to the location of each inwardly displaced segment 22 of the roll seam 16 relative to the retention tabs 24 (the location of which correspond to the axial slots 51 separating the retaining lip portions 72 ). The axial slots 51 and lip portions 72 with protrusions 56 code the base component 40 for a filter cartridge such as cartridge 10 with a roll seam having a compatible pattern of retention tabs 24 and inwardly displaced segments 22 . The roll seam 16 of a compatible filter cartridge can pass the retaining lip portions 72 , permitting complete axial reception of the cartridge housing first section 12 into the receptacle 47 so that subsequent rotation of the cartridge mounts the cartridge to the base. An incompatible cartridge (lacking, for example, the requisite inwardly displaced segments 22 ) is blocked from axial reception and cannot be mounted to the coded base.
[0048] [0048]FIGS. 12 and 13 illustrate a second representative embodiment of a base component 80 configured to receive a cartridge illustrated in FIGS. 1 - 5 . This form of filter base comprises a cast or molded component 80 with a cylindrical wall 92 defining a receptacle 87 into which the housing first section 12 of the cartridge is axially receivable. The cartridge is retained to the base by a collar 100 (illustrated in FIGS. 14 and 15) that engages the peripheral roll seam 16 . In accordance with an aspect of the present invention, the end 82 of the wall 92 is provided with a sectional configuration complementary to the annular space 20 defined between the cartridge housing first section 12 and the roll seam 16 . Radial outward projections 84 of the lip correspond to the location and outward radial displacement of the retention tabs 24 . The base component 80 may be cast with the lip 82 having locations 86 where the lip is thinned or notched to accommodate inwardly displaced segments 22 of the cartridge roll seam 16 . Alternatively, lip material may be removed after production of the base component 80 , such as by machining the lip at locations 86 .
[0049] The collar 100 includes an inward projecting thread 108 configured to engage an outward projecting thread 88 on the base component 80 . Rotation of the collar 100 relative to the base component 80 causes the collar thread 108 to ride the base thread 88 , bringing the collar retaining lip 102 to bear against the radially projecting roll seam 16 of the cartridge 10 . A spring (not shown) in the base receptacle 87 biases the cartridge 10 and collar 100 away from the base component to maintain the collar in a locked position over the end of the base thread 88 . This mounting system requires that the axially projecting lip 82 of the base component be received in the annular space 20 with room for axial movement to accommodate compression and release of the spring as the collar thread 108 rides up and over the thread 88 of the base. A rigid abutment of the cartridge roll seam 16 against the lip 82 of the base that prevents the necessary axial movement of the cartridge 10 relative to the base component 80 will prevent complete rotation of the collar 100 to its locked position.
[0050] The lip 102 of the collar 100 includes a plurality of locations 103 where the lip and adjacent structure is recessed or lip material is removed to accommodate the shape 13 (an outward deflection best seen in FIG. 1) of the cartridge housing second section 14 adjacent the outward deformation of the roll seam 16 for each retention tab 24 . In the illustrated embodiment, the collar is provided with six locations 103 where lip material is removed. The six locations 103 correspond to the six possible engaged positions of the collar 100 relative to the base component 80 and the received filter cartridge 10 . The outward deflections of the housing second section fit into three of the six locations, further enhancing the security of the collar 100 in its locked position relative to the cartridge 10 and the base component 80 by resisting unintentional reverse rotation of the collar.
[0051] A filter cartridge lacking outward deformations 24 of the roll seam 16 complementary to the outward projections 84 on the axially projecting lip 82 of the base component 80 will be blocked from axial reception and mating with the base. Similarly, filter cartridges including inward deformations of the roll seam will be rejected by a base whose axially projecting lip 82 does not include locations 86 where lip material has been removed to accommodate them. By axial reception and mating with the base, it is meant that the grommet 30 carried by the housing first section 12 fully engages the axial conduit 88 of the base component and the lip 82 of the base is received in the annular space 20 of the cartridge with room to move axially during rotation of the collar 100 to its locked position. Thus, the configuration of the axially projecting lip 82 forms a component of a cartridge compatibility matrix that codes the base for a cartridge having a particular shape of annular space 20 (as defined by deformations 24 , 22 of the roll seam).
[0052] A further aspect of the present invention contemplates a filter cartridge compatibility matrix comprising the roll seam retention tabs 24 and inward displaced segments 22 as described above and further including radial protrusions 28 of the cartridge housing section first end 12 . In the first embodiment of a filter base component 40 , a ring (not shown) is keyed to the base component to define an entrance to the receptacle 47 . The ring includes openings that allow axial passage of the radial protrusions 28 of the housing first section 12 . Once the radial protrusions 28 are axially past the ring, the receptacle 47 of the base component 40 permits rotation of the cartridge relative to the base. Radial protrusions 28 of the housing first section 12 may be used as an additional component of the cartridge compatibility matrix. The radial protrusions may also be employed to ensure a particular installed orientation of the cartridge 10 relative to the base component 40 .
[0053] The inside surface of the wall 92 defining the receptacle 87 of the second embodiment of a filter base component 80 may include axial tracks (not shown) complementary to the pattern of radial protrusions from the cartridge housing first section 12 . The tracks may be molded and/or machined on the inner surface of the receptacle of the base component 80 . A filter cartridge including an incompatible pattern of radial protrusions will be blocked from axial reception into the receptacle 87 . In combination, the configuration of the filter cartridge roll seam 16 and received housing first section 12 can be used to ensure filter compatibility and a particular installed configuration of the filter cartridge 10 relative to the base component 80 .
[0054] While preferred embodiments of the present invention have been set forth for the purposes of illustration, the foregoing descriptions should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention. | A filter assembly employs inward and outward radially displaced portions of a peripheral shoulder on the cartridge as components of a cartridge compatibility matrix. Alternative base assemblies include mounting structures complementary to the configuration of the peripheral shoulder to exclude incompatible cartridges. The peripheral shoulder is preferably a roll seam connecting first and second sections of the filter housing. The invention further contemplates a pattern of radial protrusions from a portion of the cartridge housing received in a base receptacle as part of a cartridge compatibility matrix. The base receptacle is configured to receive only those cartridges having a compatible pattern of radial protrusions. A cartridge compatibility matrix including both inward and outward deformations of a cartridge peripheral shoulder and radial protrusions of the received portion of the cartridge housing can ensure both cartridge compatibility and a particular mounted position of the cartridge relative to the base. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The preferred embodiments of the present invention are directed generally to producing a revenue stream for computer manufacturers apart from revenue associated with the sale of hardware. More particularly, the preferred embodiments are directed to user-selectable desktop customizations that indirectly promote the products and services of participating corporations.
[0005] 2. Background of the Invention
[0006] Computer manufacturers of the related art seek revenues, and therefore profits, not only from the sale of computer hardware, but also under an internet-based web traffic advertising system. In particular, computer manufacturers of the related art provide many “features” with their computers which increase traffic to internet web sites. For example, many computer manufacturers of the related art have keyboard “hot keys” that are not part of the standard or extended QWERTY keyboard, but instead are programmed to perform very specific functions, like directing the computer user's browser to a particular website. In the related art business systems, this feature is noted by the target website and the computer manufacturer receives a bounty for assisting the user in finding the website.
[0007] In related revenue models, the owner and operator of one website may have many “banner advertisements” at various locations throughout the site. If the user of the first web site transitioned to a website identified in one of the banner advertisements by activating the banner advertisement, the main web site owner may be paid a bounty for inducing the secondary web traffic.
[0008] However, as the state of the art of capitalism progresses in the internet age, companies are no longer willing to pay bounties for mere internet traffic. Stated otherwise, the advertising model of internet usage is starting to wain, lessening computer manufacturers' revenue based on the advertising type add-ons and features for consumer-based computer systems.
[0009] Thus, what is needed in the art is a new method of monetizing electronic-commerce opportunities by personal computer manufacturers.
BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS
[0010] The problems noted above are solved in large part by a method that monetizes an electronic-commerce partner of the computer manufacturer through the presentation of personal computer customizations that provide brand exposure to the partner, as well as direct links to that partner's internet sites for electronic-commerce purposes. More particularly, in the preferred embodiments, personal computer manufacturers supply computer systems where each user of a particular computer, for example each member in a household, is capable of selecting a customization having a theme that is related to the sponsor or partner's goods and/or services. Thus, in a family of four it may be possible to have four different customizations, each customization providing different thematic elements and a brand exposure to the personal computer manufacturers' partners. Further, each customization may be automatically updated over time to reflect changes in the goods and/or services of a sponsor of each theme. Revenue streams for the personal computer manufacturer in the preferred embodiments are based, in part, on an up-front cost to the partner for configuring the personal computer to support the possible selection as a customization option. An additional revenue stream of the computer manufacturer of the preferred embodiment is realized each time an end-user selects a customization that is based on the sponsor or partners goods and/or services. The computer manufacturer may also realize revenue associated with the end-user making electronic-commerce purchases from links associated with the customization. Additionally, the computer manufacturer realizes revenues based on use of programmable “hot buttons” on the key-board, each button programmable based on the particular desk-top theme, which are utilized by the end-user to view or possibly purchase products or services of the sponsor.
[0011] The disclosed devices and methods comprise a combination of features and advantages which enable it to overcome the deficiencies of the prior art devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
[0013] [0013]FIG. 1 shows a computer system of the preferred embodiment;
[0014] [0014]FIG. 2 shows a sequence for creation of a customization of the preferred embodiments;
[0015] [0015]FIG. 3 shows an exemplary screen shot of a financial customization system;
[0016] [0016]FIG. 4 shows an exemplary browser software screen customization; and
[0017] [0017]FIG. 5 shows an exemplary set of hot-keys of the preferred 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, computer 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.
[0019] 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 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.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The preferred embodiments of the present invention are directed to providing desktop themes and other customizations adapted for each user of a personal computer system which are based on products and services offered by entities associated with the manufacturer of the personal computer system. These personal computers may comprise desktop computers, laptop or portable computers, servers, and the like. Thus, the preferred embodiments will be described in this context; however, one of ordinary skill in the art, after reading and understanding the discussion below, could easily expand this technology to other computer systems that link consumers to the internet, such as, but not limited to, hand-held electronic-mail receiving and sending devices, cell phones, personal digital assistants, and the like. Thus, the term computer system should be read in its broadest sense to comprise personal computer systems as well as other digital computing and communication devices.
[0021] The preferred embodiments of the present invention are embodied in personal computers running under the Windows® XP operating system produced by Microsoft, Inc. of Redmond, Wash. While Windows® XP is preferred, any suitable operating system may be used such as, but not limited to, prior and future versions of Windows®, WinCE, Linux, Macintosh, and the like. The personal computer system of the preferred embodiment couples to and preferably is in communication with other computers acting as servers on the internet. FIG. 1 exemplifies that a computer system 10 of the preferred embodiment comprises a monitor 12 , keyboard 14 , mouse 16 , and CPU enclosure 18 coupled to the internet 20 . The computer system 10 of the preferred embodiments is a Compaq® computer; however, one of ordinary skill in the art, after reading and understanding the discussion below, could easily implement the systems and related methods on any computer system. FIG. 1 shows the computer 10 coupled to the internet 20 , and this coupling may be through any suitable means, such as a dial-up connector, Ethernet connection, digital subscriber line (DSL) connection, cable modem, or the like.
[0022] In the Windows® XP operating system, each user has the capability of having an independent logon and computer use experience. In an exemplary family of four comprising a mother, a father, an older child, and a younger child, each of the four family members may have an individual logon. The preferred embodiments of the present invention leverage the Windows® XP technology and allows the user to select from customized themes provided by the computer manufacturer that are based, in whole or in part, on the products and services of the computer manufacturers' partners or sponsors.
[0023] [0023]FIG. 2 exemplifies the preferred sequence for a user to create a customization of the preferred embodiment. In particular, the process starts (step 30 ) and in the first step a user of a new computer registers the Windows® XP operating system and creates the necessary profiles (step 31 ). Thereafter, the user drops to a log-in screen for the desktop and logs in, for the first time (step 32 ). In a computer system that does not provide customizations of the preferred embodiments, the user simply moves to the standard Windows® XP desktop at that point. However, in the preferred embodiments, dropping to the desktop for the first time preferably invokes a program that gives the user the ability to choose a customization from a customization set to be associated with their particular profile (step 34 ). As will be discussed more fully below, these customization sets may take on many variations, such as sports, kids, home/garden, financial and the like, which are, on an underlying basis, linked to the products and services of the computer manufacturers' partners. If a customization is selected (step 35 ), the customization deploys (step 36 ). If, however, at step 35 the user elects not to choose a customization step, the process immediately ends (step 38 ). Preferably, the steps shown in FIG. 2 occur each time a user logs in with their particular profile for the first time. Each time the user logs in thereafter, the customization appears automatically. The customizations offered may be generic and may comprise one or more of the following: music, movies, television, gaming, kids, sports, women's interests, education and research, travel, geography, news, and finance. Further, any individual high-level customization category may have sub-categories thereunder. For example, in the music category, users may be able to select from different types of music, for example, RAP, country, rock, classical, jazz and the like. Likewise, a user selecting a movie category as an overall customization may be able to further select subcategories such as action movies, love stories, comedies, foreign language films, particular movies of interest, and the like. The categories and/or subcategories may also be may also be brand specific, for example the sports category may be the ESPN Sports Zone, or the kids category may be identified as the Disney Kids Channel. One of ordinary skill in the art, now understanding the concepts of providing the customizations could easily create many equivalent customizations, and sub-customizations, and all such customizations would be within the contemplation of this invention.
[0024] For purposes of further discussion it is assumed that the user selects a financial customization. In the preferred embodiments, the financial customization selection may do many things. The desktop itself, for example, the desktop wallpaper, icon and cursor and colors, may change from the standard desktop. FIG. 3 shows an exemplary screen shot of a financial customization system. Note the financially oriented theme of the desktop of FIG. 3 comprising money wallpaper 22 . Additionally, the customization may set a custom screen saver following the thematic elements of the customization. Importantly for the monetization of the customization for the computer manufacturer, selection of the particular customization may also add desktop icons that are not part of the Windows® XP standard package, such as links to accounting software or software upgrades 24 . The desktop icons may include links to the computer manufacturer's partners, which in the case of a financial customization could be banks, mutual funds, stock brokers, accountants, and the like. Further customizations comprise setting the default or home website and button 26 on internet browsers to point to the computer manufacturer's partners internet sites, as well as adding links to tool bars 28 in the user's internet browser, as shown in FIG. 4.
[0025] Another customization comprises use of keyboard shortcut, “hot-keys” or “hot-buttons” to launch the internet browsers to show internet destinations of the computer manufacturers' partners. FIG. 5 shows an exemplary set of hot-keys 29 . What should be understood about this customization is that these buttons are reprogrammed depending on a particular user's selected customization and corresponding theme. Thus, the internet hot-buttons for a financial customization preferably point to the possible partners listed above, while the hot-button internet shortcuts for young children may be directed to websites for those individuals. One of ordinary skill in the art, now understanding the various desktop elements and possible additional programs that could change in the customization could easily devise many equivalent such customizations, and such equivalents would be within the contemplation of this invention.
[0026] The revenue stream of the preferred embodiment has many facets. Preferably, the computer manufacturer charges the sponsor or partner an up-front cost for installing the customization set on each personal computer manufactured. That is, regardless of whether a user actually chooses a customization that is based on the sponsor's goods and/or services, the computer manufacturer obtains a revenue stream. A second facet of the revenue stream for the computer manufacturer is when a particular customization is selected. That is, while many customizations may be available, the computer manufacturer receives a fee or bounty when a user selects the customization of a particular sponsor. The computer manufacturer preferably realizes an additional revenue stream when the customization is updated. In the preferred embodiments, updates to the customizations are provided to the user's computer automatically and over time, without (or with only minimal) interference with the user's internet use experience. After all the required information exists on the user's computer, the user is notified by way of a messaging interface that a new customization has been downloaded to their system for selection
[0027] For example, if the customization has as an underlying sponsor a movie studio, then periodically with the release of a new movie, additional customization updates may be available, such as new movie-specific screen savers and wallpaper for the desktop. If an end-user elects to install the updated customization, the computer manufacturer receives a revenue stream based on those subsequent updates.
[0028] Additional revenue streams for the computer manufacturer comprises bounties associated with generation of web traffic from the customization, for example by the user's selection of desktop icons, whose initial pages have been set to the sponsor's site, favorites links, hot buttons on keyboards and the like. The computer manufacturers' revenue stream may also be based on a percentage of net sales at electronic-commerce sites where the initial contact was based on customizations.
[0029] Many of the features of the customizations are controlled in standard application program interface (API) calls by software. Thus, in the preferred embodiments the program to prompt the user for a particular customization and apply those customizations across the standard interfaces such as wallpaper, desktop themes, and the like, may be written in any suitable programming language such as SAP, C, C++, Visual C, Visual Basic, and the like. Moreover, prompting a user of a customization as to whether they are interested in receiving an update, when available, may be done by contacting the computer manufacturer over an internet connection detected using standard internet connection software.
[0030] 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. | The specification describes a method for realizing revenue streams for computer manufacturers apart from hardware sales. More particularly, the specification discloses a method where personal computers are configured such that each user has an individual login capability, and each user may experience a different desktop theme and related overall customization. The end-user may select a particular theme, and each theme is based on the goods and/or services of a sponsor of that theme. The computer manufacturer realizes revenue initially for enabling the end-user to select particular themes, but also realizes a revenue for end-users selecting themes. Further, the specification discloses a method where computer manufacturers realize revenue by generation of internet traffic to, and electronic-commerce on, a sponsor's internet sites. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2004-67789, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a liquid container for holding a liquid to be supplied to a liquid-consuming apparatus.
2. Description of the Related Art
A liquid-ejecting apparatus provided with an ejecting head that ejects a liquid is a representative conventional liquid-consuming apparatus. An ink-jet recording apparatus provided with an ink-jet recording head for recording images is a typical example of the liquid-ejecting apparatus. Other examples of the liquid-ejecting apparatus are an apparatus provided with a coloring matter ejecting head for fabricating color filters for liquid crystal displays, an apparatus provided with an electrode forming material (conductive paste) ejecting head for forming electrodes for organic EL displays and field emission displays (FEDs), an apparatus provided with a bioorganic material ejecting head for manufacturing biochips, and an apparatus provided with a sample ejecting head as a precision pipette.
The ink-jet recording apparatus, which is a representative liquid-ejecting apparatus, is used prevalently nowadays for printing operations including color printing operations because the ink-jet recording apparatus generates comparatively low noise during a printing operation and is capable of forming small dots in a high dot density.
A liquid supply system for supplying a liquid to the liquid-consuming apparatus represented by the ink-jet recording apparatus supplies the liquid from a liquid container holding the liquid to the liquid-consuming apparatus. Generally, the liquid container used by the liquid supply system is a cartridge capable of detachably attached to the liquid-consuming apparatus to facilitate the user's work for replacing the liquid container with a new one when the liquid contained in the liquid container is exhausted.
Generally, the ink-jet recording apparatus is provided with a carriage carrying a recording head that ejects ink drops and capable of reciprocating along the recording surface of a recording medium. An ink supply system for supplying ink from an ink cartridge to a recording head mounts the ink cartridge on a carriage and supplies the ink from the ink cartridge to a recording head while the ink cartridge is reciprocated together with the recording head. Another ink supply system mounts an ink cartridge on the case or the like of the body of an apparatus, and carries ink from the ink cartridge to a recording head by a flexible tube or the like forming an ink passage.
Recently, the pigment ink is used prevalently for printing high-quality, highly weatherproof images. Although the pigment ink is capable of printing images excellent in print quality, pigment particles of the pigment ink contained in an ink container sediment so that pigment content is distributed unevenly in the ink container. Consequently, the ink-jet recording apparatus is unable to print images in an expected print accuracy after the ink-jet recording apparatus has been kept inoperative for a long time.
An ink-jet recording apparatus proposed in JP-A 60-110458 (Patent document 1) is provided with an ink stirring mechanism including a rotor and a magnetic stirrer. An ink-jet recording apparatus proposed in JP-A 11-10902 (Patent document 2) includes a main tank provided with a stirring member and a stirring bar, a subtank connected to the main tank by an ink circulating line. These mechanisms proposed in Patent documents 1 and 2 are intended to prevent the uneven distribution of pigment content by forcibly stirring the ink held in the ink container.
These mechanisms proposed in Patent documents 1 and 2 need a device including a complicated mechanism, such as the stirrer, and power for driving the complicated mechanism and, consequently, the construction of the recording apparatus is inevitably complicated. The magnetic stirrer and a stirrer driving unit, namely, driving devices for rotating the rotor and the stirring member, need to be disposed near the ink container, which places restrictions on the configuration of the recording apparatus and the recording apparatus is inevitably large.
SUMMARY OF THE INVENTION
The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide a liquid container which makes the construction of a liquid-consuming apparatus into which the liquid container is incorporated neither complicated nor large and can prevent the uneven distribution of ingredient concentration.
To solve the problems, the present invention provides a liquid container holding a liquid to be supplied to a liquid-consuming apparatus, including: a liquid pack including a flexible pouch formed of a flexible material and holding the liquid; a container body for containing the liquid pack; an expandable-and-contractile stirring chamber formed in the container body; and a pressurized fluid supply passage for supplying a pressurized fluid into the stirring chamber; wherein at least a part of the stirring chamber is formed of a low-rigidity member having a low rigidity, and the low-rigidity member is deformed by supplying the pressurized fluid into the stirring chamber through the pressurized fluid supply passage to press and deform the flexible pouch of the liquid pack by the low-rigidity member.
Preferably, the low-rigidity member of the stirring chamber presses and deforms a part of the flexible pouch of the liquid pack.
Preferably, the low-rigidity member includes a flexible film.
Preferably, the stirring chamber is formed by attaching the flexible film of a predetermined shape to an inner wall surface of the container body.
Preferably, the pressurized fluid supply passage is formed by sealing a groove formed in an inner surface of the container body with the flexible film.
Preferably, the stirring chamber has an open passage communicating with an interior space of the container body surrounding the stirring chamber, and the open passage exerts a resistance against flow of the pressurized fluid to generate a pressure sufficient to press and deform the flexible pouch of the liquid pack when the pressurized fluid is supplied into the stirring chamber.
Preferably, the open passage is formed by sealing a groove formed in the inner surface of the container body with a film.
Preferably, an interior of the container body is a sealed space, and the liquid is discharged by pressing the liquid pack by pressure of the pressurized fluid supplied through the open passage.
Preferably, the liquid container further includes a pressure chamber containing the liquid pack and formed to press the liquid pack by the pressurized fluid supplied into the pressure chamber, and the stirring chamber is formed in the pressure chamber.
Preferably, the liquid container further includes a connecting passage connecting the stirring chamber and the pressure chamber to carry the pressurized fluid supplied through the pressurized fluid supply passage into the stirring chamber to the pressure chamber. A resistance against the flow of the pressurized fluid flowing through the connecting passage is higher than a resistance against the pressurized fluid flowing through the pressurized fluid supply passage.
Preferably, the stirring chamber is disposed so as to press a lower part, with respect to a direction in which gravity acts, of the flexible pouch of the liquid pack while the liquid container is in use.
Preferably, the liquid container further includes a stirring bar placed in the flexible pouch to enhance a stirring effect of flow of the liquid in the flexible pouch of the liquid pack caused by a deformation of the low-rigidity member of the stirring chamber.
Preferably, the stirring bar is disposed near a part, which is to be deformed by the low-rigidity member of the stirring chamber when the low-rigidity member is deformed, of the flexible pouch of the liquid pack.
Preferably, the stirring bar is disposed above a part, which is to be deformed by the low-rigidity member of the stirring chamber when the low-rigidity member is deformed, of the flexible pouch of the liquid pack.
Preferably, the liquid pack is provided with a spout through which the liquid contained in the liquid pack is discharged, and the stirring bar has one end fixed to the spout.
Preferably, the liquid container is a liquid cartridge which is configured to be detachably attached to a container holding part of the liquid-consuming apparatus.
The liquid container according to the present invention having the above-mentioned characteristic features makes the construction of the liquid-consuming apparatus to which the liquid container is mounted neither complicated nor large, and can prevent the uneven distribution of ingredient concentration in the liquid held in the liquid container.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a plan view of an ink-jet recording apparatus provided with an ink cartridge in a preferred embodiment according to the present invention;
FIGS. 2A , 2 B and 2 C are a side elevation, a sectional view take on the line B-B in FIG. 2A and a side elevation of an essential part of a container body, respectively, of the ink cartridge in the preferred embodiment;
FIG. 3 is an exploded perspective view of the ink cartridge shown in FIGS. 2A to 2C ;
FIG. 4 is an exploded perspective view of the ink cartridge shown in FIGS. 2A to 2C , taken from a direction different from that from which the exploded perspective view shown in FIG. 3 is taken;
FIGS. 5A and 5B are an enlarged side elevation of an essential part of the container body of the ink cartridge shown in FIGS. 2A to 2C and a plan view of a section in a plane including a compressed air supply passage, respectively;
FIGS. 6A , 6 B and 6 C are a vertical sectional view, a sectional plan view of a section in a plane including a spout, and a sectional plan view of a stirring chamber in an expanded state, respectively, of the ink cartridge shown in FIGS. 2A to 2C ;
FIG. 7 is a partly cutaway perspective view of an ink pack included in the ink cartridge shown in FIGS. 2A to 2C ;
FIGS. 8A , 8 B and 8 C are views of a U-shaped member included in the ink cartridge shown in FIGS. 2A to 2C , taken from different angles, respectively;
FIGS. 9A , 9 B and 9 C are sectional views of the ink cartridge shown in FIGS. 2A to 2C in a state where the ink cartridge is fully filled with the ink, a state where the ink cartridge is not pressed and the ink is being consumed and a state where the ink cartridge is pressed and the ink is being consumed, respectively;
FIG. 10 is a perspective view of an essential part of a container body included in an ink cartridge in a modification of the ink cartridge shown in FIGS. 2A to 2C ;
FIG. 11 is an exploded perspective view of an ink cartridge in another modification of the ink cartridge shown in FIGS. 2A to 2C ;
FIGS. 12A , 12 B and 12 C are a perspective view, a side elevation and a sectional view taken on the line A-A in FIG. 12B , respectively, of an essential part of the container body of the ink cartridge shown in FIG. 11 ; and
FIGS. 13A and 13B are perspective views of the ink cartridge shown in FIG. 11 in a state where the ink cartridge is being assembled and a state where the ink cartridge is completed, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An ink cartridge, namely, a liquid container, for an ink-jet recording apparatus in a preferred embodiment according to the present invention will be described with reference to the accompanying drawings.
First, an ink-jet recording apparatus provided with the ink cartridge embodying the present invention will be described with reference to FIG. 1 .
Referring to FIG. 1 , an ink-jet recording apparatus 100 has a main case 101 , a platen 102 , a guide rod 103 , a carriage 104 , a timing belt 105 , a carriage driving motor 106 , and a recording head 107 , namely, a liquid ejecting head. The ink-jet recording apparatus 100 is provided with valve units 108 and a pressurizing pump 109 .
The main case 101 is a box of a shape substantially resembling a rectangular solid. The main case 101 is provided with a cartridge holder 110 in a right end part, as viewed in FIG. 1 , thereof. Four ink cartridges 1 , namely, liquid containers, in a preferred embodiment according to the present invention, are detachably mounted on the cartridge holder 110 . The four ink cartridges 1 contain a black ink, a yellow ink, a magenta ink, and a cyan ink, respectively.
The platen 102 is extended parallel to a scanning direction in which the recording head 107 moves in the main case 101 . The platen 102 supports a recording medium, not shown, fed by a paper feed means, not shown. The recording medium is fed in a feed direction perpendicular to the scanning direction.
The guide rod 103 having the shape of a bar is extended parallel to the scanning direction parallel to the platen 102 in the main case 101 . The guide rod 103 penetrates the carriage 104 so that the carriage 104 is slidable on the guide rod 103 to guide the carriage 104 disposed opposite to the platen 102 for reciprocation in directions parallel to the scanning direction.
The carriage driving motor 106 is interlocked with the carriage 104 by the timing belt 105 . The carriage driving motor 106 is supported on the main case 101 . The carriage driving motor 106 operates to drive the carriage 104 through the timing belt 105 for reciprocation along the guide rod 103 in directions parallel to the scanning direction.
The recording head 107 is provided with a plurality of nozzles to eject ink drops toward the platen 102 . The valve units 108 are mounted on the carriage 104 . The valve units 108 hold the inks temporarily, adjust the pressures of the inks and supply the inks of adjusted pressures to the recording head 107 . This ink-jet recording apparatus 100 is provided with four valve units 108 respectively for the black ink, the yellow ink, the magenta ink and the cyan ink.
The pressurizing pump 109 is connected to a pressure measuring device 112 by a connecting tube 111 . Air supply tubes 113 connect the pressure measuring device 112 to the ink cartridges 1 , respectively. The ink cartridges 1 are connected to the valve units 108 by ink supply tubes 114 , respectively.
An ink cartridge 1 in a preferred embodiment according to the present invention will be described with reference to FIGS. 2A to 9C .
The ink cartridge 1 includes a container body 11 having the shape of a rectangular solid as shown in FIGS. 2A to 2C . As shown in FIGS. 3 and 4 , the container body 11 has a main member 12 having one open side, and a cover 13 for hermetically covering the open side of the main member 12 .
A formed film member 14 is attached to the inner surface of the main member 12 . The formed film member 14 is formed of a film and has a solid part of a predetermined three-dimensional shape and a flat part of a predetermined planar shape. A U-shaped member 15 substantially resembling the letter U and an ink pack 10 are contained in the container body 11 . The ink pack 10 includes a flexible pouch 16 holding the ink.
As shown in FIGS. 8A to 8C , the U-shaped member 15 has a pair of restricting parts 17 and a holding cross bar 18 having opposite ends connected to the restricting parts 17 . The restricting parts 17 are in contact with bent walls 16 a ( FIGS. 3 and 4 ), which bend as the ink contained in the ink pack 10 is consumed, of the flexible pouch 16 to restrict the bent walls 16 a from bending outward and to make the bent walls 16 a bend inward. The restricting parts 17 extend substantially over the overall length of the flexible pouch 16 of the ink pack 10 in the back-and-forth direction.
As shown in FIGS. 6A and 9C , each of the restricting parts 17 has a width substantially corresponding to the thickness of an interior space in the container body 11 and has a length substantially corresponding to the overall length of the container body 11 in the back-and-forth direction. As shown in FIGS. 8A to 8C , each restricting part 17 is provided with a plurality of triangular ribs (transverse contact parts) 17 a and a longitudinal, straight rib (longitudinal contact part) 17 b . The triangular ribs 17 a come into linear contact with the bent wall 16 a of the flexible pouch 16 of the ink pack 10 along the entire thickness of the flexible pouch 16 . The longitudinal, straight rib 17 b comes into contact with the bent wall 16 a of the flexible pouch 16 along a straight line in the back-and-forth direction of the ink pack 10 .
Referring to FIGS. 3 and 4 , a holding slope 19 is formed in the back end of the space in the main member 12 . A tapered back end part of the flexible pouch 16 of the ink pack 10 is held between the holding slope 19 and a sloping part 18 a ( FIGS. 8B and 8C ) of the holding cross bar 18 of the U-shaped member 15 to secure a back part of the ink pack 10 . A holding slope 20 is formed in the front end of the space in the main member 12 . A tapered front end part of the flexible pouch 16 of the ink pack 10 is held between the holding slope 20 and the sloping surface of a front holding member 21 disposed in a front part of the space in the container body 11 to secure a front part of the ink pack 10 .
As shown in FIGS. 3 and 4 , a spout 22 is attached to the front end of the flexible pouch 16 . The spout 22 is fitted in an opening 12 a formed in the front wall of the main member 12 of the container body 11 . A gap between the spout 22 and the side surface of the opening 12 a is sealed by a sealing member 23 . The ink contained in the ink pack 10 is discharged through the spout 22 .
The open side of the main member 12 is hermetically covered with a film 25 to form a pressure chamber 26 in the container body 11 as shown in FIGS. 5A and 5B . The recording apparatus supplies compressed air into the pressure chamber 26 to compress the flexible pouch 16 of the ink pack 10 to deliver the ink held in the ink pack 10 to the recording apparatus.
As shown in FIGS. 5A and 5B , a protrusion (low-rigidity member) 14 a of the formed film member 14 defines an expandable-and-contractile stirring chamber 27 in the pressure chamber 26 . A compressed air supply passage 28 is formed to extend from an outer wall surface of the container body 11 to the inside thereof, so as to supply compressed air into the stirring chamber 27 . A part of the compressed air supply passage 28 is formed by sealing a groove 29 formed in the inner surface of a wall of the main member 12 of the container body 11 with a projecting part 14 b of the formed film member 14 .
The stirring chamber 27 communicates with the pressure chamber 26 by means of an open passage 30 . The open passage 30 is formed by sealing a groove 31 formed in the inner surface of the wall of the main member 12 of the container body 11 with a flat part 14 c of the formed film member 14 . The groove 31 forming the open passage 30 exerts a resistance against the flow of compressed air supplied into the stirring chamber 27 so that a pressure capable of compressing and deforming the flexible pouch 16 of the ink pack 10 is generated in the stirring chamber 27 . More specifically, the groove 31 forming the open passage 30 has a narrow width and is formed like a labyrinth as shown in FIG. 5A . Thus resistance exerted by the open passage 30 against the flow of the compressed air is higher than that exerted by the compressed air supply passage 28 against the flow of the compressed air.
As shown in FIG. 5A , compressed air can be surely supplied into the stirring chamber 27 through the compressed air supply passage 28 in a state where the stirring chamber 27 is fully compressed by the ink pack 10 fully filled up with the ink because the groove 29 defining the compressed air supply passage 28 is extended and connected to the entrance of the open passage 30 in the stirring chamber 27 .
Referring to FIGS. 6A to 6C and 7 , a stirring bar 24 is placed in the flexible pouch 16 of the ink pack 10 and the front end of the stirring bar 24 is fixed to the spout 22 . The stirring bar 24 is provided with many slant grooves 24 a to enhance the stirring effect of the stirring bar 24 . As shown in FIG. 6A , the stirring chamber 27 is disposed in a lower part of the container body 11 so as to press a lower part, with respect to a direction in which gravity acts, of the flexible pouch 16 of the ink pack 10 while the ink cartridge 1 is in use. The stirring bar 24 is disposed near and above a part, which is to be deformed due to the deformation of the stirring chamber 27 , of the flexible pouch 16 of the ink pack 10 .
Functions of the ink cartridge 1 in this embodiment will be described with reference to FIGS. 9A to 9C .
FIG. 9A shows the ink pack 10 fully filled with the ink of a new ink cartridge 1 . When the ink pack 10 is fully filled with the ink, the ink pack 10 maintains the same shape both in a pressurized state where compressed air is supplied into the container body 11 and an unpressurized state where compressed air is not supplied into the container body 11 .
From a state shown in FIG. 9A , as the ink is consumed and the quantity of the ink contained in the ink pack 10 decreases, the thickness of an upper part of the flexible pouch 16 of the ink pack 10 decreases as shown in FIG. 9B where no compressed air is supplied into the container body 11 .
When the pressurizing pump 109 is actuated to supply compressed air through the compressed air supply passage 28 into the stirring chamber 27 in a state shown in FIG. 9B , the stirring chamber 27 expands so as to bulge out toward the flexible pouch 16 of the ink pack 10 as shown in FIG. 9C . Consequently, a lower part of the flexible pouch 16 of the ink pack 10 is pressed and partially deformed and the ink contained in the flexible pouch 16 is caused to flow and is stirred. The stirring bar 24 disposed near and above the part of the flexible pouch 16 deformed by the expanded stirring chamber 27 disturbs the flow of the ink in the flexible pouch 16 to enhance the stirring effect of the flow of the ink.
The compressed air supplied into the stirring chamber 27 flows through the open passage 30 into the pressure chamber 26 . Consequently, the flexible pouch 16 of the ink pack 10 is compressed and the ink can be urged to flow from the ink cartridge 1 toward the recording apparatus.
Thus, at the start of the printing operation of the recording apparatus, the stirring chamber 27 is expanded to carry out an automatic stirring operation for stirring the ink contained in the flexible pouch 16 , before the flexible pouch 16 of the ink pack 10 of the ink cartridge 1 in this embodiment is compressed to supply the ink to the recording apparatus. Since compressed air is not supplied to the stirring chamber 27 while the recording apparatus is not in operation, unnecessary compression of the flexible pouch 16 of the ink pack 10 can be avoided while the recording apparatus is not in operation. The construction of the recording apparatus can be simplified by using a common pressure source for both pressing the ink pack 10 and expanding the stirring chamber 27 .
The stirring operation by the expansion of the stirring chamber 27 may be performed not only at the start of the printing operation, but also at any suitable time when necessary.
The pressurizing pump 109 may be capable of alternately performing a discharge operation and a suction operation to make the stirring chamber 27 perform expansion and contraction alternately.
As apparent from the foregoing description, the ink cartridge 1 in this embodiment is capable of surely preventing the uneven distribution of ingredient concentration in the ink contained therein without intensifying the structural complicacy of the ink-jet recording apparatus and without enlarging the ink-jet recording apparatus. When a pigment ink is used for printing, the ink cartridge 1 is particularly effective in preventing the uneven sedimentation of the pigment particles in the ink cartridge 1 .
As obvious from FIG. 9B , the upper bent wall 16 a of the flexible pouch 16 of the ink pack 10 bends as the ink contained in the ink pack 10 is consumed. The restricting part 17 restricts the bending of the upper bent wall 16 a so that the upper bent wall 16 a surely bends inward. Thus it is possible to prevent the outward bending of the bent wall 16 a of the flexible pouch 16 and resultant increase in resistance against the bending of the bent wall 16 a , and increase in the quantity of the ink that is unused and remains in the ink pack 10 .
Since the triangular ribs 17 a of the restricting part 17 are in contact with the bent wall 16 a of the flexible pouch 16 of the ink pack 10 over the entire width of the bent wall 16 a in the direction of the thickness of the bent wall 16 a , the concentration of impulsive force on the folding line of the bent wall 16 a can be avoided when the flexible pouch 16 of the ink pack 10 is compressed, and the restricting parts 17 are able to hold the ink pack 10 securely in place in the container body 11 .
Particularly, in the ink cartridge 1 in this embodiment, the bent walls 16 a of the flexible pouch 16 of the ink pack 10 are pressed against the restricting parts 17 when the stirring chamber 27 is expanded for a stirring operation. Then, it is very effective to avoid the concentrated, repetitive application of impulsive force on the bent walls 16 a.
Unification of the restricting parts 17 and the holding cross bar 18 in a single member reduces the number of parts.
The flexible pouch 16 of the ink pack 10 of the ink cartridge 1 in this embodiment is compressed by compressed air when the recording apparatus operates for printing. An ink cartridge provided with an ink pack that is not compressed when the recording apparatus operates for printing may be provided with the foregoing stirring mechanism and restricting parts.
An ink cartridge in a modification of the ink cartridge 1 in the preferred embodiment will be described with reference to FIG. 10 .
As shown in FIG. 10 , restricting parts 17 are formed integrally with a container body 11 . The restricting parts 17 are formed on the inner surface of a main member 12 included in the container body 11 at intervals along the length of an ink pack 10 in the back-and-forth direction. The restricting parts 17 are in contact with the bent wall 16 over substantially entire thickness of the flexible pouch 16 of the ink pack 10 .
The ink cartridge in the modification is expected to have the same effect as that of the foregoing embodiment. Moreover, since the restricting parts 17 are formed integrally with the container body 11 , the number of parts can be reduced and manufacturing processes can be simplified.
Referring to FIGS. 11 to 13B showing an ink cartridge in another modification, a container body 11 includes a main member 12 having an open front end and a cover 13 hermetically covering the open front end of the main member 12 . An O-ring 32 is held between the main member 12 and the cover 13 to seal the container body 11 . The modification does not need any member corresponding to the film 25 shown in FIGS. 3 and 4 .
The upper and the lower walls of the main member 12 of the ink cartridge in the modification are bent inward so as to protrude into the interior of the main member 12 to form restricting parts 17 having a triangular cross section.
The ink cartridge in the modification is expected to have the same effect as that of the foregoing embodiment. Moreover, since the ink cartridge in the modification does not need any members corresponding to the film 25 and the restricting parts 17 separate from the main member 12 shown in FIGS. 3 and 4 , the number of parts can be reduced and manufacturing processes can be simplified.
Although the invention has been described in terms of the preferred embodiments thereof with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof. | A liquid container includes a liquid pack having a flexible pouch holding the liquid, a container body containing the liquid pack, an expandable-and-contractile stirring chamber formed in the container body, and a pressurized fluid supply passage for supplying a pressurized fluid into the stirring chamber. At least a part of the stirring chamber is formed of a low-rigidity member. A pressurized fluid is supplied through the pressurized fluid supply passage into the stirring chamber to press and deform the low-rigidity member by the pressure of the pressurized fluid. The deformed low-rigidity member presses and deforms the flexible pouch of the liquid pack. The liquid container prevents the uneven distribution of ingredient concentration in the liquid contained in the liquid container without complicating and enlarging a liquid-consuming apparatus. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to magnetoresistive read sensors and particularly to the free layer formations of such sensors operating in a tunneling magnetoresistive (TMR) configuration and current-perpendicular-to-plane GMR configurations.
2. Description of the Related Art
In simplest form, the usual giant magnetoresistive (GMR) read sensor consists of two magnetic layers, formed vertically above each other in a parallel planar configuration and separated by a conducting, but non-magnetic, spacer layer. Each magnetic layer is given a unidirectional magnetic moment within its plane and the relative orientations of the two planar magnetic moments determines the electrical resistance that is experienced by a current that passes from magnetic layer to magnetic layer through the spacer layer. The physical basis for the GMR effect is the fact that the conduction electrons are spin polarized by interaction with the magnetic moments of the magnetized layers. This polarization, in turn, affects their scattering properties within the layers and, consequently, results in changes in the resistance of the layered configuration. In effect, the configuration is a variable resistor that is controlled by the angle between the magnetizations.
The magnetic tunneling junction device (TMR device) is an alternative form of GMR sensor in which the relative orientation of the magnetic moments in the upper and lower magnetized layers (also called electrodes in this configuration) controls the flow of spin-polarized electrons tunneling through a very thin dielectric layer (the tunneling barrier layer) formed between those electrodes. When injected electrons pass through the upper electrode, as in the GMR device, they are spin polarized by interaction with the magnetization direction (direction of its magnetic moment) of that electrode. The probability of such an electron then tunneling through the intervening tunneling barrier layer into the lower electrode then depends on the availability of states within the lower electrode which the tunneling electron can occupy. This number, in turn, depends on the magnetization direction of the lower electrode. The tunneling probability is thereby spin dependent and the magnitude of the current (tunneling probability times number of electrons impinging on the barrier layer) depends upon the relative orientation of the magnetizations of magnetic layers above and below the barrier layer.
In what is called a spin-filter configuration, one of the two magnetic layers in both the GMR and TMR has its magnetization fixed in direction (the pinned layer), while the other layer (the free layer) has its magnetization free to move in response to an external magnetic stimulus. If the magnetization of the free layer is allowed to move continuously, as when it is acted on by a continuously varying external magnetic field, the GMR and TMR device each effectively acts as a variable resistor and it can be used as a read-head.
The difference in operation between the GMR sensor discussed first, and the TMR sensor just now discussed, is that the resistance variations in the former are a direct result of changes in the electrical resistance (due to spin polarized electron scattering) within the three-layer configuration (magnetic layer/non-magnetic, conducting layer/magnetic layer), whereas in the TMR sensor, the amount of current is controlled by the availability of states for electrons that tunnel through the dielectric barrier layer that is formed between the free and pinned layers.
When used as a read head, (called a TMR read head, or “tunneling magnetoresistive” read head) the free layer magnetization is moved by the influence of the external magnetic fields of a recorded medium, such as is produced by a moving hard disk or tape. As the free layer magnetization varies in direction, a sense current passing between the upper and lower electrodes and tunneling through the dielectric barrier layer varies in magnitude as more or less electron states become available. Thus a varying voltage appears across the electrodes. This voltage, in turn, is interpreted by external circuitry and converted into a representation of the information stored in the medium.
A typical spin-filter GMR sensor structure is the following:
Seed/Antiferromagnetic Layer/AP2/Ru/AP1/Cu/Free Layer/Capping Layer.
A typical spin-filter TMR sensor structure is the following:
Seed/Antiferromagnetic Layer/AP2/Ru/AP1/AlOx/Free Layer/Capping Layer,
In the TMR configuration shown above (and in the GMR as well), the seed layer is an underlayer required to form subsequent high quality magnetic layers. The antiferromagnetic layer is required to pin the pinned layer, ie., to fix the direction of its magnetic moment by exchange coupling. The pinned layer itself is now most often a synthetic antiferromagnetic (SyAF) (also termed a synthetic antiparallel (SyAP)) structure with zero total magnetic moment. This structure is achieved by forming an antiferromagnetically coupled tri-layer denoted as AP2/Ru/AP1, which is to say that two ferromagnetic layers, denoted AP1 and AP2, are magnetically coupled across a Ru spacer layer in such a way that their respective magnetic moments are mutually antiparallel and substantially cancel each other. The structure and function of such SyAP structures is well known in the art and will not be discussed in further detail herein. The conducting, but non-magnetic Cu spacer layer of the GMR is replaced in the TMR by (for example) a thin insulating layer of oxidized aluminum that can be oxidized in any of several different ways to produce an effective dielectric tunneling barrier layer. The free layer in both the GMR and TMR is usually a bilayer of ferromagnetic material such as CoFe/NiFe, and the capping layer in both the GMR and TMR is typically a layer of tantalum (Ta). The bilayer choice for the free layer is necessitated by the fact that an effective free layer should be magnetically soft (of low coercivity), which is an attribute of the NiFe layer, yet it must also be an effective spin polarizer of conduction electrons, which is an attribute of the CoFe layer. We shall see below that the structure of the free layer can be significantly altered to provide an improved GMR or TMR sensor.
Superficially, the TMR structure differs from the GMR configuration by the replacement of a conducting Cu spacer layer in the GMR with an oxidized aluminum (AlOx) tunneling barrier layer in the TMR. Although this seems to be a minor substitution, the physical basis of the operation of the two structures is substantially different and, in addition, the dimensions of the various layers are also quite different.
The advantage of the TMR configuration compared to the GMR configuration is that the TMR configuration has a higher MR ratio, dR/R, (ratio of maximum resistance variation as the free layer magnetic moment changes direction, dR, to total device resistance, R), which is a measure of its efficacy as a read sensor. For example, while typical GMR ratios of GMR read sensors are less than 10%, ratios on the order of 70% have been reported for tunneling junction configurations used as MRAM devices rather than as read head sensors. The present invention will show a read head TMR sensor with a MR ratio on the order of 30%. In addition, the TMR sensor is operated in a CPP (current perpendicular to plane) mode, since it is required that the electrons tunnel through the barrier layer from the pinned layer to the free layer. GMR sensors, on the other hand, can operate either in the CPP mode or in the CIP (current in plane) mode, wherein electrons move laterally through the pinned/spacer/free layer configuration.
The CPP mode required of the TMR sensor increases overall sensor resistance, R, as the sensor layers are scaled down and made narrower and thinner to better enable their use in reading high density recorded media. To maintain a useful sensor resistance range, the thickness of the AlOx has to be reduced to less than 7 angstroms to achieve a low areal resistance, RA, in the range of approximately several ohm-μm 2 . As a consequence, of the decreasing RA, the MR ratio of the sensor also decreases. Thus, one of the major challenges for the design of TMR sensors is to improve the MR ratio while keeping RA low.
Much recent experimentation on GMR sensors has been directed at improvements in the free layer structure. The most common structure in both the GMR and TMR sensor had been a CoFe/NiFe bilayer, in which the NiFe layer provides the required softness, while the CoFe provides good spin polarization of conduction electrons. More recently, work has been done on improving the magnetic properties of both free and pinned layers by utilizing novel materials and laminated structures. Most notable of the novel materials has been CoFeB, an alloy of cobalt, iron and boron. Noma et al. (U.S. Pat. No. 6,493,196) teach a pinned layer formed as a tri-layer of NiFe/CoFeB/CoFe and Hosami et al. (U.S. Pat. No. 6,828,785) disclose a laminated free layer of CoFe, NiFe and CoFeB. Aoshima et al. (U.S. Pat. No. 6,046,892) show a free layer of CoFeB/NiFe and the present inventors, in Wang et al. (U.S. Pat. No. 6,844,999) teach a boron-doped (CoFeB) free layer. In fact, the use of a CoFeB free layer is taught in several patents, including Slaughter et al (U.S. Pat. No. 6,831,312), Fukuzawa et al. (U.S. Pat. No. 6,338,899) and Hayashi (U.S. Pat. No. 6,101,072). Slaughter, in particular, suggests that the amorphous nature of CoFeB is advantageous in a tunneling junction type sensor because it increases the smoothness of various layers and generally enhances the sensor's magnetic performance.
The present inventors have been investigating possible ways of improving the free layer structure for both a GMR and a TMR sensor. In the TMR sensor, the function of the free layer and the constraints placed upon the free layer are different than those in the GMR sensor and it is not necessarily true that free layer structures that are advantageously used in the GMR sensor will have similar benefits in the TMR sensor. To achieve a high MR ratio, the growth process of the barrier layer must produce a layer of great smoothness and the process by which it is oxidized must be exceptionally well controlled. In addition, the nature of the magnetic structures on either side of the barrier layer, namely the AP1 layer of the pinned layer and the contiguous portion of the free layer are also extremely important. In fact, it will be an object of the present invention to produce a free layer, suitable for both CPP configuration GMR sensors and TMR sensors that will enhance their respective MR ratios, while maintaining good magnetic softness (low coercivity) and providing an adjustable magnetostriction.
SUMMARY OF THE INVENTION
A first object of this invention is to provide a method of forming a TMR sensor that combines a high MR ratio, low free layer coercivity and a low areal resistance (RA).
A second object of the present invention is to provide a method of forming a TMR sensor that allows adjustment of its magnetostriction properties.
A third object of the present invention is to provide a method of forming a GMR sensor having a CPP configuration or a CCP CPP configuration and a low free layer coercivity, high GMR ratio and a low areal resistance.
A fourth object of the present invention is to provide a method of forming a GMR sensor having a CPP configuration or a CCP CPP configuration that allows adjustment of its magnetostriction properties.
These objects will be met by the formation within both the CPP and CCP CPP configured GMR sensor and the TMR sensors of a novel tri-layered free layer having the structure:
CPP structure: CoFe(25%)/CoFeB/NiFe(10%) TMR structure: CoFe(70%)/CoFeB/NiFe(10%), where percentages refer to Fe atom percent.
This structure has demonstrated outstanding magnetic softness (low coercivity) and low magnetostriction.
When formed within the CPP GMR spin valve, this free layer has produced a dR/R of 9.8% and a small areal resistance of only 0.17 ohm-micron 2 squared in a structure having a cross-sectional area of approximately 0.05 micron 2 . This is a significant improvement over more conventional CPP structures.
In the TMR sensor, the same tri-layered structure is used, with the CoFe layer being formed to a thickness between approximately 2 and 30 angstroms, the CoFeB layer (which may be alloyed with other elements such as Ni) being formed to a thickness range between approximately 5 and 40 angstroms and the NiFe layer being formed to a thickness between approximately 5 and 80 angstroms. It is to be noted that much higher MR ratios, up to approximately 30%, can be obtained in the TMR sensor and, when formed with a horizontal circular cross-sectional shape of approximately 0.6 microns diameter, the sensor produced an areal resistance of 4.0 ohm-micron 2 .
The TMR Structure.
CoFeB is a promising candidate for inclusion into a TMR free layer since its use in MRAM structures has produced a very high MR of up to 70% (see Dexin Wang et al.: “70% TMR at Room Temperature for SDT Sandwich Junctions with CoFeB as Free and Reference Layers,” IEEE Transactions On Magnetics, Vol. 40, No. 4, 2004, p. 2269)
However, when the CoFeB material is introduced into the free layer of a low RA TMR structure (as opposed to an MRAM type structure) the MR ratio becomes even lower than the typical CoFe/NiFe. Table 1, below shows the measured properties of four sample TMR devices with different free layers and tunnel barrier layers. Each sample has a horizontal circular cross-section of diameter 0.6 microns and the same generic structure:
Seed Layer/AF pinning layer/CoFe/Ru/CoFeB/Al/NOX/Free Layer/Capping Layer
TABLE 1 Sample Structure dR/R RA(Ωμm 2 ) H c (Oe) 1 Al = 5.75, FL = CoFe(70%)10/NiFe(10%)40 22.4% 4.6 4.7 2 Al = 5.75, FL = CoFe(20%)B(20%)19/NiFe(10%)40 18.1% 4.6 3.4 3 Al = 5.0, FL = CoFe(70%)10/NiFe(10%)40 25.4% 4.0 4.7 4 Al = 5.0, FL = CoFe(70%)10/CoFe(20%)B(20%)10/NiFe(10%)40 30.1% 4.0 5.0
Notation in the table above is as follows: Al=5.75 denotes a 5.75 angstrom thick layer of Al to be oxidized by a process of natural oxidation (NOX). CoFe(70%)10/ denotes a 10 angstrom thick layer of CoFe with Fe 70% by number of atoms. H c denotes the coercivity of the free layer. The unit of coercivity is Oersteds (Oe) and the unit of areal resistance (RA) is Ωμm 2 (ohms times square microns).
As can be seen from the properties of samples 1 and 2, the replacement of the CoFe layer in sample 1 by the CoFeB layer in sample 2 actually lowers the MR from 22.4 to 18.1, which is not a good result. Comparing sample 3 to sample 4, however, shows how the problem has been solved by including the CoFe(20%)B(20%) layer within a tri-layer, wherein that CoFeB layer is sandwiched between CoFe and NiFe layers. The tri-layered configuration of sample 4 has a higher MR than the bi-layered configuration of sample 3. It is the opinion of the inventors that the improvement in MR ratio that results from the tri-layering of the CoFeB results from the fact that the CoFeB is no longer in direct contact with the oxidized Al layer and there is no interdiffusion between the CoFeB and the oxidized Al. It is to be noted that although CoFe(20%)B(20%), with the percentage of B atoms being 20% and the percentage of Fe atoms being 20% has been preferred herein, values of Fe between 5%-90% and B between 5%-30% fulfill the objects of the invention. When oxidized Al is used in a TMR read head application, as in the present invention, the formation of a thin barrier is most easily accomplished by using a relatively weak method of oxidation, such as natural oxidation (simply allowing the deposited Al layer to come in contact with oxygen in an oxidation chamber). This process is easily controlled and allows us to maintain a low RA. As a result of natural oxidation, however, the oxidized Al layer is formed in a so-called under-oxidized state, in which interdiffusion between it and the contiguous free layer occurs easily. In the formation of an MRAM element, however, the Al layer is fully oxidized by means of radical shower oxidation (a bombardment of the Al layer with energetic oxygen radicals) or by plasma oxidation (a similar contact between the Al layer and energetic particles). In those cases, the interdiffusion is not the problem it is in sensor formation. A similar problem occurs when CoFeB is used as the AP1 layer in the antiferromagnetically coupled pinned layer. Thus, to eliminate the interdiffusion problem, we place a CoFe layer between the CoFeB and the oxidized Al barrier layer. As can be seen from the table, sample 4, which uses the tri-layer, is a significant improvement over the other sample free layer structures and shows a 20% gain in MR over the reference structure, sample 3. Finally, it is to be noted that the magnetostriction of the free layer can be controlled during its formation by varying the composition or thickness of the NiFe layer or the other two layers.
The GMR Structure.
When used in a CPP configured GMR rather than the TMR described above, the tri-layer free layer is formed within two different sensor configurations, the more usual CPP configuration and a “confined current path” or CCP-CPP configuration.
In the former configuration, the general structure and placement of active layers is:
Seed/AFM pinning/AP2/Ru/[CoFe_Cu]/Cu 30/[CoFe/NiFe]/cap,
Where CoFe_Cu denotes a layer of Cu laminated onto the CoFe to increase the interfacial scattering of conduction electrons.
In this configuration the AFM pinning layer is a layer of antiferromagnetic material that is exchange coupled to the SyAP pinned layer. The SyAP pinned layer is a tri-layer of a ferromagnetic material, denoted simply AP2, a Ru coupling layer and a second ferromagnetic layer (normally denoted AP1), that is here formed as a layer of CoFe laminated onto on a thin layer of Cu. The pinned layer is separated from the free layer by a Cu spacer layer approximately 30 angstroms in thickness and a composite CoFe/NiFe bilayer forms the free layer.
In a CCP-CPP configuration, as described by Sakakima et al. (U.S. Pat. No. 5,715,121), an additional CCP structure is inserted between AP1 and the free layer, as follows:
[Ta/Ru]seed/AFM pinning/AP2/Ru/[CoFe_Cu]/Cu/CCP-layer/Cu/[CoFe/NiFe]/cap
The CCP layer in this structure is a layer formed of conducting particles segregated within an insulating material, so that the particles form a conducting pathway. In the following preferred embodiment, Cu particles segregated within a layer of oxidized aluminum will be used as the CCP layer, but other combinations of segregated particles of conducting material within a dielectric matrix will also form a CCP layer.
In either of the two cases shown above, the AP1 and AP2 layers are in the thickness range between approximately 20-50 angstroms and the free layer thickness is in the thickness range between approximately 30-60 angstroms. For read head applications, the free layer should have a small coercivity, H c , of less than 10 Oe and a low magnetostriction in the order of between 10 −8 and 10 −6 to reduce stress induced anisotropy. In addition, the sensor configuration must have a sufficiently high CPP GMR ratio. A composite CoFe(10%)/NiFe(17.5%) is commonly used because of a small H c of approximately 5 Oe and a low magnetostriction of approximately 2×10 −6 . Its CPP GMR ratio, dR/R, however, is not large enough and must be improved.
It is known that the CPP GMR ratio depends greatly on the spin polarization properties of the AP1 and the free layer materials. Typically, the greater the degree of spin polarization of conduction electrons, the higher the GMR ratio. In bulk Co(100-x)Fe(x) alloys, the spin polarization property usually increases with increasing value of x (a percentage), the Fe content in atom percent. Therefore, it might be expected that the GMR ratio will be higher with Co(100-x)Fe(x) layers, with x>10%, used in the AP1 and free layers. The inventors have already demonstrated that an AP1 layer having x=50% significantly improves upon a layer having x=10%, increasing the resulting GMR ratio by between 15% and 20%. Similarly, with a free layer of [CoFe(25%) 10/NiFe(17.5%) 35] replacing a free layer of [CoFe(10%) 12/NiFe(17.5%) 35], the GMR ratio gains between approximately 10% and 15% with a similar RA. We have also demonstrated that replacing the already improved CoFe(50%) AP1 layer by a CoFe(70%) AP1 layer, which is a choice made in forming the preferred embodiment, there is an additional 12% GMR ratio improvement. Therefore, it seems clear that CoFe alloys richer in Fe, very effectively enhance GMR ratios.
We have also demonstrated that a composite free layer of [CoFe(25%) 20/NiFe(10%) 28] produces the best dR/R with a comparable H c and magnetostriction. This comparison data is shown in Table 2 below. This particular combination is unique since the magnetic moment of NiFe(10%) is very small and its magnetostriction is negative, while the magnetic moment of CoFe(25%) is only slightly larger than that of CoFe(10%) and its magnetostriction is slightly positive. As a result, the [CoFe(25%)/NiFe(10%)] composite free layer will allow the maximum contribution from the bulk scattering properties of the CoFe(25%) while maintaining free layer softness (low H c ) and small magnetostricition.
Furthermore, we observed that with a thin CoFe(20%)B(20%) layer inserted between the interface of the CoFe(25%) and NiFe(10%) layers, the CPP dR/R shows additional gain of approximately 10% even with a reduction of RA (areal resistance). The inventors believe that the CoFeB contributes to the interfacial scattering, which is more important in producing the CPP GMR improvement than in producing the TMR improvement. Our reasoning is as follows. CoFeB has a very large coefficient of spin polarization. When the CoFeB layer is combined with a high spin polarization BCC (crystalline) layer of CoFe(25%), the total spin polarization is enhanced. Some of these results are also shown in Table 2 below. Overall, comparing this new tri-layered free layer with the conventional free layer, the dR/R improvement is significant. We believe that the additional dR/R improvement is a result of an enhancement of interfacial scattering as well as bulk scattering due to the intrinsically high spin polarization produced by the CoFeB layer as noted above.
In Table 2 below, the seed layer for all 4 sample structures is Ta/NiCr. The antiferromagnetic pinning layer is IrMn. AP2 is CoFe(25%), AP1 is CoFe(70%) laminated onto a thin Cu layer, ie. [CoFe_Cu] and formed to a thickness of 36 angstroms. Each sample includes a CCP layer that is a layer of AlCu formed between two Cu layers in a configuration of the form Cu/AlCu/Cu in which the first Cu layer is approximately 5.2 angstroms in thickness, the AlCu CCP layer is approximately 8.5 angstroms in thickness and the final Cu layer is approximately 3 angstroms in thickness. To form the CCP layer, the Al is oxidized and the Cu becomes a segregated metal path within the resulting AlOx, using a combined process of RF-PIT and RF-IAO (which are, respectively, plasma assisted ion and argon/oxygen ion processes). Within the table, an expression such as CoFe(25%)20 indicates a layer of CoFe formed to a thickness of 20 angstroms and being 25% Fe by number of atoms.
TABLE 2 Sample Free Layer RA(Ωμm 2 ) dR/R H c Lambda 1 CoFe(10%) 12/NiFe(17.5%) 35 0.25 8% 4.3 Oe 2.00 × 10 −6 2 CoFe(25%) 10/NiFe(17.5%) 35 0.25 8.8% 4.5 Oe 2.30 × 10 −6 3 CoFe(25%) 20/NiFe(10%) 28 0.2 9.23% 4.9 Oe 7.00 × 10 −8 4 CoFe(25%) 12/CoFe (20%)B(20%) 10/NiFe(10%) 35 0.17 9.8% 4.2 Oe 1.00 × 10 −6
It should be noted in Table 2 above that the use of CoFe(25%) can be replaced by CoFe(50%) or CoFe(70%) and similarly for CoFe(20%)B(20%) and NiFe(10%), with appropriate changes in the other atom percents. It should also be noted that sample 4 in the table above produces exceptional values of areal resistance, MR ratio, coercivity and “lambda,” which is the coefficient of magnetostriction. Finally, it should be noted that while the tri-layer free layer of sample 4 constitutes a preferred embodiment, the tri-layer can be repeated to form a multi-layered laminated free layer that will also meet the objects of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a spin-valve TMR sensor utilizing the tri-layered free layer of the present invention.
FIG. 2 is a schematic representation of a spin-valve GMR sensor formed in the CCP-CPP configuration and using the tri-layered free layer of the present invention.
FIG. 3 is a schematic representation of a spin-valve GMR sensor formed in the CPP configuration, without the CCP layer and using the tri-layered free layer of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first preferred embodiment of the present invention is a TMR sensor structure of improved areal resistance, improved free layer coercivity, improved magnetoresistive ratio (dR/R) and improved magnetostriction qualities. This improvement is obtained by the introduction of a tri-layer free layer comprising a CoFeB layer interposed between CoFe and NiFe layers.
Referring first to FIG. 1 , there is shown in schematic form a cross-sectional view through a vertical plane of a TMR sensor stack with conduction lead layers and magnetic biasing layers not illustrated. It is understood that the layers in the stack are most typically formed by a process of sputtering from appropriate targets, with the exception of layers that require additional processing as will be noted. Looking at the layered structure from the bottom to the top, there is shown first a seed layer ( 10 ), which can be a layer of Ta/NiCr with the Ta formed to a thickness between approximately 5 and 30 angstroms, with 20 angstroms being preferred and the NiCr formed to a thickness between approximately 30 and 80 angstroms with 50 angstroms being preferred.
On the seed layer is then formed a pinning layer ( 20 ) of an antiferromagnetic material such as a layer of IrMn formed to a thickness between approximately 40 and 100 angstroms with 70 angstroms being preferred.
On the pinning layer there is then formed a pinned layer ( 30 ), which in this preferred embodiment is a SyAP tri-layer comprising two ferromagnetic layers ( 32 ), ( 36 ) separated by an antiferromagnetically coupling layer ( 34 ). A proper choice of material and thickness of the ferromagnetic layers and the coupling layer allows the magnetic moments of the ferromagnetic layers to align themselves in antiparallel directions, thus reducing the net magnetic moment of the tri-layer to essentially zero, while the pinning layer fixes the magnetic moment direction of the layer ( 32 ). In the present embodiment, layers ( 32 ) and ( 36 ) can both be layers of CoFe(25%) formed to thicknesses between approximately 10 and 50 angstroms with 20 angstroms being preferred, while layer ( 34 ) can be a layer of Ru formed to a thickness between approximately 7 and 8 angstroms with 7.5 angstroms being preferred.
On the SyAP tri-layer there is then formed a tunneling barrier layer ( 38 ) which is preferentially a layer of Al, formed to a thickness between approximately 4 and 8 angstroms with 5 angstroms being preferred, which is then naturally oxidized to form a layer of AlOx. The oxidation process preferentially takes place in an oxidation chamber in which oxygen gas is fed in at a rate of 10-2000 sccm. The process of natural oxidation, is preferred over plasma assisted oxidation or radical shower oxidation when producing the very thin tunneling barrier layers that are preferred in the present invention.
On the oxidized Al tunneling barrier layer there is then formed a tri-layer free layer ( 40 ), comprising layers ( 42 ), ( 44 ) and ( 46 ). Layer ( 42 ), which contacts the barrier layer, is preferentially a layer of CoFe (70%) formed to a thickness between approximately 2 and 30 angstroms with approximately 10 angstroms being preferred. It is to be noted that other elements, such as Ni, may be alloyed into the CoFe alloy and still achieve the objects of the invention. Layer ( 44 ) is preferably a layer of CoFe(20%)B(20%), but an alloy in which the atom percent of Fe ranges between approximately 5%-90% and the atom percent of B ranges correspondingly between approximately 5%-30% is acceptable and will meet the objects of this invention. The CoFeB is formed to a thickness between approximately 5 and 40 angstroms, with approximately 10 angstroms being preferred. This CoFeB layer, too, may be alloyed with other elements, such as Ni, Nb or Zr. Layer ( 46 ) is a layer of NiFe (10%) formed to a thickness between 5 and 80 angstroms with approximately 40 angstroms being preferred. This layer can be alloyed with other materials, such as Co, B, Nb or Zr. Again, it must also be noted that, in addition to the tri-layered free layer just described, multiple laminations of the magnetic layers ( 42 ), ( 44 ) and ( 46 ) can be formed into a composite free layer and still meet the objects of the invention. The composite multi-layered free layer, of which the tri-layer is exemplary of the preferred embodiments described herein, can be equally well formed within the second and third embodiments described below.
On the tri-layered free layer (or a composite free multi-layer) there is then formed a capping layer ( 50 ) which can be a bilayer of Ta/Ru, in which the Ta layer ( 52 ) can be formed to a thickness between approximately 5 and 100 angstroms and the Ru layer ( 54 ) can be formed to a thickness between approximately 5 and 200 angstroms.
It is to be noted that the magnetostriction qualities of the sensor, as measured by the coefficient of magnetostriction, lambda, can be controlled during fabrication by varying the thicknesses of the three layers that comprise the free layer.
The second preferred embodiment of the present invention is a CCP CPP GMR (confining current path-current perpendicular to the plane-giant magnetoresistive) sensor structure of improved areal resistance, improved free layer coercivity, improved magnetoresistive ratio (dR/R) and improved magnetostriction qualities. These improvements are obtained by the introduction of a tri-layer free layer comprising a CoFeB layer interposed between CoFe and NiFe layers.
Referring now to FIG. 2 , there is shown in schematic form a cross-sectional view of a CCP-CPP GMR sensor stack with conduction lead layers and magnetic biasing layers not illustrated. It is understood that the layers in the stack are most typically formed by a process of sputtering from appropriate targets, unless a particular processing step is noted. Looking at the layered structure from the bottom to the top, there is shown first a seed layer ( 10 ), which can be a layer of Ta/NiCr with the Ta formed to a thickness between approximately 10 and 60 angstroms, with 50 angstroms being preferred and the NiCr formed to a thickness between approximately 10 and 40 angstroms with 20 angstroms being preferred.
On the seed layer is then formed a pinning layer ( 20 ) of an antiferromagnetic material such as a layer of IrMn formed to a thickness between approximately 45 and 100 angstroms with 70 angstroms being preferred.
On the pinning layer there is then formed a pinned layer ( 30 ), which in this preferred embodiment is a SyAP tri-layer comprising two ferromagnetic layers ( 32 ) and ( 36 ), denoted AP2 and AP1 respectively, separated by an antiferromagnetically coupling layer ( 34 ). A proper choice of material and thickness of the ferromagnetic layers and the coupling layer allows the magnetic moments of the ferromagnetic layers to align themselves in antiparallel directions, thus reducing the net magnetic moment of the tri-layer to essentially zero, while the pinning layer fixes the magnetic moment direction of the AP2 layer ( 32 ). In the present embodiment, layer ( 32 ) can be a layer of CoFe(25%) formed to a thickness between approximately 15 and 60 angstroms with approximately 46 angstroms being preferred, while layer ( 34 ) can be a layer of Ru formed to a thickness between approximately 7 and 8 angstroms with 7.5 angstroms being preferred. Preferably in the present invention, AP1 layer ( 36 ) is a tri-layer comprising a first pair, ( 37 ) & ( 38 ) of sequentially formed identical layers, each layer being itself a laminated bilayer comprising a layer of CoFe(70%), of thickness between approximately 5 and 15 angstroms with approximately 12 angstroms being preferred, laminated to a thin layer of Cu of thickness between approximately 0.5 and 5 angstroms, with approximately 2 angstroms being preferred. The thin, laminated Cu layer (indicated by a horizontal line) is found to improve interfacial scattering of conduction electrons and to, thereby, enhance sensor performance. Upon this first pair, ( 37 )&( 38 ), is then laminated a third layer ( 39 ), which is a layer of CoFe(70%) formed to a thickness between approximately 5 and 15 angstroms with approximately 12 angstroms being preferred. The entire triply laminated AP1 layer thereby has the following form:
[CoFe(70%)_Cu][CoFe(70%)_Cu]CoFe(70%).
On the laminated AP1 layer there is then formed a combined spacer layer and CCP layer ( 40 ). This structure comprises a first Cu spacer layer ( 42 ), which in this embodiment is a layer of Cu formed to a thickness between approximately 2 and 8 angstroms, with approximately 5.2 angstroms being preferred. Upon this first spacer layer is then formed the CCP layer ( 44 ), which is preferentially an initially formed bilayer of Al/Cu (other combinations being possible), formed to a thickness between approximately 3 and 12 angstroms with approximately 8.5 angstroms being preferred, which is then processed to form a layer of AlOx within which are segregated particles of Cu that form a conducting pathway. The oxidation and segregation process preferentially comprises a first RF PIT process followed by a second RF IAO process. The RF PIT process requires (20 W 50 sccm 40 s). The RF IAO process requires an Ar/O mixture at a ratio of 50/0.8 at 27 W. It is noted that Al/Cu can be replaced by other combinations in which one layer is oxidized and the other layer is segregated.
Following the formation of the CCP layer, a second conducting, non-magnetic spacer layer is formed ( 46 ) which is a layer of Cu formed to a thickness between approximately 1 and 5 angstroms with approximately 3 angstroms being preferred.
On the second spacer layer there is then formed a tri-layer (or multi-layered) composite free layer ( 50 ), comprising layers ( 52 ), ( 54 ) and ( 56 ). Layer ( 52 ), which contacts the second spacer layer, is preferentially a layer of CoFe (25%) formed to a thickness between approximately 5 and 30 angstroms with approximately 12 angstroms being preferred. It is to be noted that other elements, such as Ni, Nb, and Zr may be alloyed into the CoFe alloy and still achieve the objects of the invention. Layer ( 54 ) is a layer of CoFe(20%)B(20%), formed to a thickness between approximately 5 and 40 angstroms, with approximately 10 angstroms being preferred. The percentages of Fe may range between approximately 5% and 90% and the percentages of B may range between approximately 5% and 30% and still meet the objects of the invention. This layer, too, may be alloyed with other elements, such as Ni, Nb and Zr. Layer ( 56 ) is a layer of NiFe (10%) formed to a thickness between 5 and 80 angstroms with approximately 35 angstroms being preferred. This layer can be alloyed with other materials, such as Co, Nb, Zr and B.
On the tri-layered free layer there is then formed a capping layer ( 60 ) which can be a four layer composite layer of Cu 30/Ru 10/Ta 60/Ru 10, in which the Cu layer ( 62 ) is formed to a thickness between approximately 5 and 50 angstroms with approximately 30 angstroms being preferred, the first Ru layer ( 64 ) is formed to a thickness between approximately 5 and 30 angstroms with approximately 10 angstroms being preferred, the Ta layer ( 66 ) is formed to a thickness between approximately 10 and 80 angstroms with approximately 60 angstroms being preferred and the second Ru layer ( 68 ) is formed to a thickness between approximately 5 and 50 angstroms with approximately 10 angstroms being preferred. This four layer capping layer has been found to improve the GMR ratio and to facilitate processing.
As already noted in the description of the TMR sensor, the magnetostriction properties of the CCP CPP GMR sensor can also be adjusted by varying the thicknesses or Fe percentages of the layers forming the composite free layer. It should, in fact, be noted that Fe percentages between 5% and 90% are permissable in the free and pinned layers and will meet the objects of the invention.
Referring finally to FIG. 3 , there is shown a CPP GMR sensor formed in accord with the present invention in which the CCP layer described above is omitted. In all other respects the structure and formation of the CPP GMR sensor without the CCP layer is the same as that illustrated in FIG. 2 and described in the foregoing for the CCP CPP GMR sensor. Layer 44 (CCP layer) of FIG. 2 is not formed and there is only one spacer layer ( 40 ), in FIG. 3 , replacing the two spacer layers ( 42 ) and ( 46 ) in FIG. 2 . Even without the CCP layer, the composite free layer described above provides improved coercivity, GMR ratio and magnetostriction.
As is understood by a person skilled in the art, the preferred embodiments of the present invention are illustrative of the present invention rather than limiting of the present invention. Revisions and modifications may be made to methods, materials, structures and dimensions employed in forming and providing a TMR, a CPP GMR or a CCP CPP GMR sensor incorporating a tri-layered composite free layer, while still forming and providing such a device and its method of formation in accord with the spirit and scope of the present invention as defined by the appended claims. | A TMR sensor, a CPP GMR sensor and a CCP CPP GMR sensor all include a tri-layered free layer that is of the form CoFe/CoFeB/NiFe, where the atom percentage of Fe can vary between 5% and 90% and the atom percentage of B can vary between 5% and 30%. The sensors also include SyAP pinned layers which, in the case of the GMR sensors include at least one layer of CoFe laminated onto a thin layer of Cu. In the CCP CPP sensor, a layer of oxidized aluminum containing segregated particles of copper is formed between the spacer layer and the free layer. All three configurations exhibit extremely good values of coercivity, areal resistance, GMR ratio and magnetostriction. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved threshold preamplifier circuit for use in a scintillation camera.
2. Description of the Prior Art
Scintillation cameras are widely used as diagnostic tools for analyzing the distribution of a radiation-emitting substance in an object under study, such as for the medical diagnosis of a human body organ. A typical scintillation camera of a type to which the present invention is applicable is a commercial version of the Anger-type scintillation camera, the basic principles of which are described in U.S. Pat. No. 3,011,057.
The scintillation camera can take a "picture" of the distribution of radioactivity throughout an object under investigation, such as an organ of the human body which has taken up a diagnostic quantity of a radioactive isotope. A scintillation camera of the Anger-type produces a picture of the radioactivity distribution by detecting individual gamma rays emitted from the distributed radioactivity in the object and passing through a collimator to produce a scintillation in a thin planar scintillation crystal. The scintillation is detected by a bank of individual photomultiplier tubes which view overlapping areas of the crystal. Appropriate electronic circuits translate the outputs of the individual photomultiplier tubes into X and Y positional coordinate signals and a Z signal which indicates generally the energy of the scintillation event and is used to determine whether the event falls within a preselected energy window. A picture of the radioactivity distribution in the object may be obtained by coupling the X and Y signals which fall within the preselected energy window to a display, such as a cathode ray oscilloscope which displays the individual scintillation events as spots positioned in accordance with the coordinate signals. The detection circuitry typically provides for integrating a large number of spots onto photographic film.
The "resolution" of a scintillation camera refers to the degree of ability of the camera faithfully to reproduce the spatial distribution of the radioactivity which is within the field of view of the device. The overall intrinsic resolution of the Anger camera detector is generally dependent on the ability of the detector to signal accurately the position coordinates of each scintillation event. There are many operations involved in the detection of each scintillation event and the signalling of its position coordinates. It has been found that the information contributed by photomultiplier tubes distant from the location of a scintillation event is substantially less accurate than that contributed by near tubes because it is based on relatively few photons arising from the scintillation event. The error or inaccuracy is compounded by the long "lever arm" associated with the distant tubes. Thus, a threshold preamplifier circuit has been developed, as described in U.S. Pat. No. 3,732,419 for improving the resolution of a scintillation camera by giving greater weight to the signals from tubes close to the location of a scintillation event than to signals from photomultiplier tubes which are more distant. This non-linear amplification scheme is accomplished by providing a threshold preamplifier circuit which has an input-output transfer characteristic such that input signals at a magnitude more than a preselected threshold magnitude produce substantially no output signal and input signals of a magnitude greater than the preselected threshold magnitude produce an amplified output signal which is substantially proportional to the magnitude of the input signal above the threshold magnitude. In conventional circuits of this type, the threshold value is selected as a constant voltage chosen as a percentage (typically one percent) of the anticipated peak of the energy for the isotope under study.
The threshold is applied to the output of each photomultiplier tube, to reduce the effect on the coordinate positioning analysis of signals received from tubes which are distant from the location of the scintillation event in the crystal. When the threshold is applied to the output of each tube, the X and Y signals change very little because the thresholding amplifiers remove a small (a light that was reflected many times) amount of signal from both sides of the axis, which cancels out in the differential summing. The Z channel after thresholding, however, which comprises the sum of all the energy signal outputs from the photomultiplier tubes can change a great deal as compared with the unthresholded Z output as the thresholding setting is changed. This causes an increase in X and Y position gain as threshold is increased. While this difference can be compensated for where a single isotope energy is being studied, difficulties arise where more than one energy source is being received. Where dual isotopes are being studied, the threshold in conventional systems is set to a single constant value as determined by the energy of the lowest energy isotope to be used. This causes the image size for the higher energy isotope incidence to be changed when used at the same time with a lower energy isotope or an isotope with multiple peaks.
SUMMARY OF THE INVENTION
The present invention provides an improved threshold preamplifier circuit for a scintillation camera including means for varying the threshold value setting in accordance with the incident energy of the scintillation event.
In a preferred embodiment of this invention, this circuit means is a dynamic threshold preamplifier circuit in which the summed and integrated unthresholded outputs of the preamplifier are used to adjust the threshold on the thresholded output of the preamplifiers to provide a threshold that is proportional to the energy of the event being processed, thereby giving a constant image size for all energies.
There have thus been outlined rather broadly certain objects, features and advantages 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, of course, additional features of the invention that will be described more fully hereinafter. Those skilled in the art will appreciate that the conception on which this disclosure is based may readily be utilized as a basis for the designing of other arrangments for carrying out the purposes of this invention. It is important, therefore, that this disclosure be regarded as including such equivalent arrangements as do not depart from the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings forming a part of the specification, wherein:
FIG. 1 is a combination of FIGS. 1A and 1B which are schematic circuit diagrams of the electronics of an Anger-type scintillation camera incorporating dynamic threshold circuitry according to the invention;
FIGS. 2A-2D show representative voltage waveforms at points A-D of FIG. 2; and
FIG. 3 is a detailed circuit diagram of part of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, an Anger-type scintillation camera has a plurality of photomultiplier tubes PM-1 through PM-N (typically 19 or 37 tubes mounted in a hexagonal array behind a scintillation crystal) which function together to detect the scintillation event that occurs when a gamma ray impinges on the scintillation crystal (the tubes PM-1 through PM-N are labelled "PHOTO DETECTORS" in FIG. 1). For purposes of simplification, only the circuitry associated with the first three photomultiplier tubes PM-1, PM-2 and PM-3 is illustrated in detail in FIG. 1. The details of the circuitry of FIG. 1 are described only insofar as they contribute to an understanding of the principles, structure and operation of the claimed invention which relates to the preamplifier and threshold portions of FIG. 1. The reader is referred to U.S. Pat. Nos. 3,011,057 and 3,984,689 for further details of the more conventional aspects of the illustrated circuitry.
The outputs of the respective photomultiplier tubes PM-1 through PM-N are separately coupled to respectively corresponding preamplifier circuits A1 ("PREAMP"). Each preamplifier circuit A1 has an output coupled to a separate threshold amplifier circuit A2 ("THRESHOLD"). Each of the threshold amplifiers A2 subtracts a prerequisite threshold voltage from the output of the particular preamplifier A1 with which it is associated. The threshold voltage is established as a function of the energy of the incoming scintillation event, as more fully described below. An amplifier A23 with a feedback loop employing a resistor R46 supplies a threshold bias to the threshold amplifiers A2. The outputs from the respective threshold amplifiers A2 are applied to a resistor matrix ("MATRIX") and are used for generating an actual displacement of an electron beam on a cathode ray tube (CRT) display.
The preamplifiers A1 also have outputs, connected through resistors R15, R23 and R35 directly to a "Z NO THRESHOLD" signal line of the resistor matrix, that are summed to provide an unthresholded energy signal Z nt which represents the total energy of the scintillation event. The unthresholded energy signal Z nt is passed through amplifiers A24 and A25 to an integrating amplifier A26, to provide an integrated energy signal Z u . The integrated signal Z u is delivered as an input to an analyzer 21 which looks at the signal Z u to see if it falls within a preselected energy window.
The signal Z u is also connected through a variable resistor R50 to serve as an input to a summing amplifier A23. The unthresholded output Z nt , after passing through amplifier A24 and variable resistor R49, also connects as an input to the summing amplifier A23. A third input to the amplifier A23 comes from the resistor R47 which is variable connected to resistor R48 to provide a preselected constant biasing voltage. The output of the summing amplifier A23 is the sum of the unthresholded energy signal Z nt amplified by amplifier A24, the integrated unthresholded energy signal Z u and the preset constant voltage determined by the resistors R47 and R48. This summed signal provides a threshold voltage signal which is applied to the threshold amplifiers A2.
The threshold amplifiers A2 operate to pass the preamplifier A1 output signals to the resistor matrix ("MATRIX") and summing amplifiers A4 through A8 ("SUM") whenever the output signal from the corresponding preamplifier A1 exceeds the value of the threshold voltage. If the output of any of the respective preamplifiers A1 is below the threshold, the output signal of the corresponding threshold amplifier A2 is substantially zero.
In this manner, the larger output signals of the photomultiplier tubes PM-1 through PM-N closest to the location of the scintillation event are passed to the resistor matrix ("MATRIX") and summing amplifiers A4 through A8 ("SUM") for determination of the X, Y positional coordinate signals of the scintillation event. The smaller output signals which come from photomultiplier tubes PM-1 through PM-N which are distant from the location of the scintillation event are not passed to the resistor matrix, and are thus not considered in the statistical analysis which determines the position of the event. From the thresholded preamplifier A1 outputs, the resistor matrix and summing amplifiers A4 through A8 develop positional coordinate output signals +Y, -Y, +X, -X, and a thresholded energy signal Z t . The +Y, -Y and +X, -X outputs are fed to differential amplifiers A9 and A10 respectively, where the +Y and -Y signals and the +X and -X signals are subtracted. The Z t output is fed to the amplifier A11. The resulting signals are then passed to integrating amplifiers A12, A13 and A14 ("INTEGRATION" ).
As already stated, the analyzer 21 looks at the Z u signal to see if the energy of the event falls within the preselected energy window. If the value of Z u is within the acceptable range, the analyzer 21 actuates the gate control circuit 16 which opens gates to the sample and hold circuits B1, B2 and B3 ("BUFFER"), thereby permitting the integrated signals from integrating amplifiers A12, A13 and A14 ("INTEGRATION") to be processed further. (If no actuating signal is received, switches S4, S5 and S6 apply discharge signals to the ingetrating circuits to prevent further processing.) The integrated X, Y and Z t signals are then applied to ratio computation circuitry (amplifiers A15, A16 and multipliers 17, 18 labelled "RATIO COMPUTATION" in FIG. 1) where the X and Y signals are divided by the thresholded energy signal Z t to produce X and Y positional coordinate signals for the image event. The X and Y signals are then passed to the CRT display.
For every scintillation event whose Z u signal falls within the preselected energy window, the CRT display produces a spot on a screen at a location corresponding to the input position coordinates X and Y received from the ratio computation circuitry. The orientation switches P1 through P8 ensure that the correct orientation exists with regard to the X and Y deflection signals. The voltage waveform of a representative output signal from a preamplifier A1 at a point "A" in FIG. 1 caused by the detection of a scintillation event is shown in FIG. 2A. This signal, and all similar signals delivered at the outputs of the respective preamplifiers A1 of photomultiplier tubes PM-1 through PM-N in response to detection of the event, is passed through the connecting resistor (R23 for PM-2) to the "Z NO THRESHOLD" signal line of the resistor matrix ("MATRIX"). The signals are summed together to give an unthresholded energy reference signal Z nt , corresponding to the total energy of the incident scintillation event. The voltage waveform of the Z nt signal has the same shape as the signal of FIG. 2A, being the sum of the separate unthresholded preamplifier A1 output signals.
This unthresholded energy signal Z nt is applied to the inverting input of the amplifier A24 with associated feedback resistor R52 and produces an output signal proportional to the total energy of the image event. FIG. 2B shows the voltage waveform of a representative signal appearing at point "B" of FIG. 1 in response to detection of an event. The voltage waveform of the signals at points "A" and "B" (FIGS. 2A and 2B) are similar, except that the signal at point "B" is inverted. The signal at point "B" is thereafter applied as an input to the amplifier A25 and to the integrator A26, which has associated feedback capacitor C8 and discharging switch S7, to generate an integrated energy output signal Z u . The voltage waveform for a representative Z u signal taken at a point "C" of FIG. 1 is shown in FIG. 2C.
The unthresholded energy output signal of the amplifier 24 and the integrated energy output signal of the integrator 26 are added to each other by the summing amplifier A23 which has feedback resistor R46. The summed output signal of amplifier A23 serves as the threshold voltage signal which is applied as a reference voltage to the separate threshold amplifiers A2. The voltage waveform of a representative threshold voltage output of amplifier A23 taken at a point "D" in FIG. 1 is shown in FIG. 2D. "V TH " indicates the threshold voltage value.
The variable resistors R49 and R50 respectively serve as a means for adjusting the relative contributions of the unthresholded energy signal (output of amplifier A24) and the integrated energy signal (output of integrator A26) to the threshold voltage signal output of amplifier A23. The resistors R47 and R48 provide a preselected constant biasing voltage input to the voltage sum output of amplifier A23 and serve to set the zero image energy level threshold value. The resistors R47 to R50 are typically set to give a zero energy level bias of 6.9 volts and a threshold pulse of approximately one to two percent of the peak output of the preamplifiers A1.
FIG. 3 shows the detailed configuration of the summing amplifier A23 and associated circuit components R47 through R50. The structure shown in FIG. 3 can be formed as part of an integrated circuit board layout including other circuitry shown in FIG. 1. The preferred amplifier component is a 2527 operational amplifier such as commercially available from Harris Corporation. However, those skilled in the art will appreciate that any fast operational amplifier or discrete transistor may be used. An LH0002 power buffer, such as available from National Semiconductor Corporation, is used at the output of the 2527 amplifier to provide low impedance to drive the common threshold inputs of the threshold amplifiers A2. The unthresholded energy signal Z nt (amplified by amplifier A24) that appears at point "B" in FIG. 1 (see FIG. 2B for voltage waveform) is applied through a 20K ohm variable resistor and 1.5K ohm fixed resistor (together the resistor R49 of FIG. 1) to the inverting input of the 2527 amplifier. The integrated energy signal Z u that appears at point "C" in FIG. 1 (see FIG. 2C) is likewise applied through a 20K ohm variable resistor and a 2.49K ohm fixed resistor (together R50 of FIG. 1) to the inverting input of the 2527 amplifier. A switch "S" serves to permit optional removal of these incident event energy dependent components from the threshold voltage calculation. The constant biasing voltage input to the inverting input of the 2527 amplifier is provided through a variable 5K ohm resistor (R 48 of FIG. 1) and a fixed 9090 resistor (R47 of FIG. 1). The output of the LH0002 power buffer stage serves as the threshold voltage setting signal at point "D" in FIG. 1 (see FIG. 2D) which is applied to the threshold amplifiers A2.
Conventional scintillation camera detection circuits have thresholding components that serve to process the signals received from photomultiplier tubes close to the scintillation event with greater weight than the signals received from photomultiplier tubes which are distant from the event. Such thresholding components operate with respect to a constant threshold reference voltage which is preset at a value, such as one to two percent of the anticipated peak amplitude of the preamplifiers (as determined by the incident energy of events of the lowest energy isotope expected to be used). With the tresholded value set in this manner, however, the threshold energy reference Z t signal (the sum of the thresholded energy outputs of the separate preamplifiers) for scintillation events caused by isotopes of different energies can vary by as much as 15 to 20 percent. This causes undesired errors in depicting the position of each event on a display, since the positional reference signals X and Y are determined by dividing the positional coordinates X and Y by the thresholded energy sum signal Z t . The invention provides means for setting the threshold value of the threshold components of the detection circuitry in response to the incident energy of the scintillation event, thereby providing a dynamic threshold which overcomes the disadvantages of the fixed threshold of prior art devices.
Having thus described the invention with particular reference to the preferred form of circuitry, it will obvious to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the claims appended hereto. | An improved threshold preamplifier circuit is disclosed for use with the event X, Y position detection circuitry of a scintillation camera. Threshold amplifiers, having a common threshold voltage that is set as a function of the energy of the incident scintillation event, control the respective preamplified photomultiplier tube output signals so that signals from tubes close to the event receive greater weight in the X, Y position analysis than signals from distant tubes. In a preferred embodiment, the threshold voltage is determined by the output of a summing amplifier which sums an unthresholded energy signal Z nt which represents the total energy of the incident event, an integrated energy signal Z u which represents the integrated value of the unthresholded energy signal Z nt , and a constant voltage which represents the preselected zero energy level threshold biasing voltage. Variable resistors control the relative contributions to the summing amplifier input of the Z nt and Z u energy signals. The invention overcomes the shortcoming of prior art constant threshold voltage circuits that the size of displayed images (determined by the computation of X, Y ratios using thresholded energy signals Z t ) varies for detection of events caused by multiple energy isotopes and dual isotopes with different energies. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 12/898,868 filed Oct. 6, 2010 (now abandoned), which claims priority to U.S. Provisional Patent Application Nos. 61/249,064 filed on Oct. 6, 2009 and 61/299,256 filed on Jan. 28, 2010, which applications are incorporated herein by reference in their entireties.
BACKGROUND
Footwear that covers a user's ankles, commonly referred to as boots, are typically either of the slip-on type or are of the type that includes mechanisms that are tightened to hold the boot securely against the foot during use and loosened to facilitate foot entry and exit from the boot.
Slip-on boots can be quicker and easier to take on and off than boots with tightening mechanisms that are loosened and tightened for foot exit and entry. However, to account for foot entry and exit from slip-on boots, the inner volume of slip-on boots is often substantially larger than the volume of the foot that the boot is intended to fit. The relative large inner volume of such boots can result in a poor fit, as the user's foot can substantially slide around in the boot during use.
SUMMARY
The present disclosure provides a slip-on boot with fit features that enable an improved fit while still allowing for convenient foot entry and exit from the boot. Related methods of using and manufacturing a slip-on boot are also provided.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side view of a footwear according to the principles of the present disclosure;
FIG. 2 is a back view of the footwear of FIG. 1 ;
FIG. 3 is a cross-sectional view of the footwear of FIG. 1 along line 3 - 3 of FIG. 2 ;
FIG. 4 is a cross-sectional view of the footwear of FIG. 1 showing a foot moving into the footwear;
FIG. 5 is a cross-sectional view of the footwear of FIG. 1 with a foot seated in the footwear;
FIG. 6 is a cross-sectional view of the footwear of FIG. 1 along line 3 - 3 of FIG. 2 ;
FIG. 7 is a side view of a footwear according to an alternative embodiment of the footwear of FIG. 1 ;
FIG. 8 is back view of the footwear of FIG. 7 ;
FIG. 9 is a cross-sectional view of a portion of FIG. 7 ;
FIG. 10 is a cross-sectional view of the footwear of FIG. 7 showing a foot moving into the footwear;
FIG. 11 is a cross-sectional view of a prior art footwear;
FIG. 12 is a side view of a last according to an embodiment of the present disclosure;
FIG. 13 is a side view of the last of FIG. 11 with the heal portion slid away from the main body portion;
FIGS. 14 and 15 are side views of a footwear partially removed from the last of FIG. 12 ; and
FIG. 16 is a side view of the last of FIG. 16 with a slip sheet.
DETAILED DESCRIPTION
Referring to FIGS. 1-10 , embodiments of the footwear according to the present disclosure are shown. In the depicted embodiments the footwear is a slip-on boot where the foot fitting volume (the inner volume of the boot) is not as highly adjustable as compared to boots that have laces configured to be loosened to allow foot entry/exit and tightened to secure the boot onto the user's foot.
In the depicted embodiment, the shape and size of the inner volume of the slip-on boot approximates the shape and size of the user's foot. The close approximation results in a fit that helps secure the user's foot in the boot 10 . In some prior art slip-on boot configurations the foot fitting volume of the foot fitting portion of the boots is significantly larger than the foot that the boot is designed to fit. The large difference between the volumes is provided for clearance that is typically provided for foot entry and exit from the slip-on boot. Referring to FIG. 11 , a prior art slip-on boot configuration is shown. The solid line labeled 304 represents the inner surface of the boot, the solid line labeled 300 represents the silhouette of user's foot and lower leg in a fully seated position in the boot, and the broken line labeled 302 represents the silhouette of the user foot and lower leg in an intermediate position in the boot (moving into or out of the boot). Such prior art slip-on boot configurations result in an undesirable sloppy fit (e.g., the user's foot substantially moves around within the boot during use, the user's heel sliding up and down within the boot during use).
In the depicted embodiment, the boot 10 is configured to press against the user's foot 30 to prevent the foot from inadvertently pulling out of the boot during use. In the depicted embodiment, the boot 10 presses back against the heel and instep of the user's foot when the user raises his or her foot, thereby holding the foot 30 securely within the boot 10 as the user walks. See FIG. 5 illustrating that the boot 10 according to the depicted embodiment is configured to hold down at least the user's heel 32 and instep 34 when the user raises his or her foot, as when he or she takes a step. In the depicted embodiment, the boot 10 does not need to apply constant downward pressure on the user's foot in order for the fit feature to function. In other words, the boot 10 of the present disclosure does not need to impinge on the user's foot in order to stay secured to the user's foot. The boot of the depicted embodiment, provides for some clearance between the users foot and the boot to avoid the user's clothing (pant leg, sock, etc.) from bunching. However, it should be appreciated that in an alternative embodiment, the boot could be configured to apply constant pressure on the user's foot.
The boot 10 of the depicted embodiment of the present disclosure is configured to apply a comfortable and secure fit without actually impinging on the user's foot. The boot 10 of the depicted embodiment is configured so that the clearance between the boot and foot is relatively consistent. However, it should be appreciated that in alternative embodiments the boot may include specific sections that are configured to apply force to the user's foot that are adjacent oversized areas for clearance.
In the depicted embodiment, the fit of the boot is determined in part by the internal shape of the boot. In particular, the boot 10 of the embodiment shown in FIGS. 1-6 has no mechanisms (e.g., laces, buckles, straps, etc.) in the instep area 23 for tightening the boot onto the user's foot. In the depicted embodiment the boot also does not have mechanisms in the calf area 13 (above the instep area) for tightening the boot 10 over the user's leg. However, it should be appreciated that in alternative embodiments the boots can include various tightening mechanisms. For example, the boots according to the present disclosure can have tightening mechanisms configured to facilitate tucking the user's pant leg into the boot and tightening the boot over the user's pant leg (see FIGS. 7-10 ). It should be appreciated that boots according to alternative embodiments of the present disclosure could also have auxiliary mechanisms in the instep area for tightening and loosening the boot. In addition to the below the knee type boots shown in FIGS. 1-10 , boots according to alternative embodiments can be above the knee boots such as waders and may include straps that connect to a waist belt or may includes straps that are configured to extend over a persons shoulders.
Referring to FIGS. 1-6 , the boot 10 of the present disclosure is described in greater detail. Boot 10 includes an upper 12 connected to a sole 14 . In the depicted embodiment the sole 14 is constructed of a rubber material. The upper 12 is also primarily constructed of a rubber material. In the depicted embodiment the upper 12 is primarily constructed of vulcanized rubber material over a neoprene (polychloroprene) material. The boot 10 includes a waterproof construction. In the depicted embodiment the vulcanized rubber material is molded over the neoprene material. It should be appreciated that boots according to the present disclosure can be constructed of many other types of materials and according to other construction methods (e.g., other rubber materials: styrene-butadiene rubber, synthetic rubber, blown rubber with or without stretch fabrics, or other elastic materials or elastic constructions (accordion leather), stretch gore, etc.).
The upper 12 includes a foot fitting portion 16 and a lower leg and ankle covering portion 18 connected above the foot fitting portion 16 . The foot fitting portion includes a toe covering portion 20 at the toe end and a heel cup 22 at the heel end. The upper 12 includes an instep covering portion 24 that extends over the front side of the upper across the foot fitting portion 16 and the lower leg and ankle covering portion 18 .
In the depicted embodiment, the upper includes a flexible zone 26 that extends along the back side of the upper directly above the heel cup 22 .
In the depicted embodiment the flexible zone 26 of the boot 10 bulges outwardly when a user's heel presses against the flexible zone 26 during inserting and removal of a user's foot 30 from the boot 10 (see FIG. 4 ). Referring to FIG. 4 , the solid line labeled 306 represents the inner surface of the boot and the broken line labeled 308 represents the silhouette of the user's foot and lower leg in an intermediate position in the boot (moving into or out of the boot). In the depicted embodiment the maximum deflection O of the flexible zone 26 is between 0.5 to 1.5 inch (e.g., 0.75 inches). Once the user's foot 30 is within the boot 10 , the user's foot fits relatively snuggly within the boot 10 (see FIG. 5 ). In the depicted embodiment, the foot fitting volume of the foot fitting portion 16 of the boot 10 is only marginally larger than the volume of the foot that the boot 10 is designed to fit, as compared to traditional prior art loose fit slip-on boots (see FIG. 11 ).
In the depicted embodiment, the boot 10 is sized to fit a 9D (US) size foot. The overall height S of the boot 10 is between 11.0 to 13.0 inches, the length U of the boot 10 is between 11.5 to 12.5 inches, the maximum inner circumference T of the opening located at the top end of boot is between 15.0 to 17.0 inches, and the minimum inner circumference Q located at the transition between the foot fitting portion 16 and the lower leg and ankle covering portion 18 is between 12.0 to 13.5 inches. In the depicted embodiment the internal length D of the boot 10 is greater than 10.0 inches. It should be appreciated that the principles of the present disclosure are applicable to other boot sizes as well (e.g., the principles apply to boots of various sizes that are of the same model of the size 9D boot described therein).
Referring primarily to FIG. 2 , in the depicted embodiment the width P of the flexible zone 26 is between 2.0 to 3.0 inches, the height N of the top of the flexible zone 26 is between 6.5 to 8 inches, and the height M of the bottom of the flexible zone 26 is between 4.0 to 6.0 inches. The area of the flexible zone is between 4.0 to 9.0 square inches. In the depicted embodiment the flexible zone 26 is an exposed portion of neoprene that is completely surrounded by vulcanized rubber covered neoprene.
Referring primarily to FIG. 3 , in the depicted embodiment the curvature of the heel cup 22 is measured by the maximum bulge Mbulge and is between 0.5 to 1.5 inches. The maximum bulge Mbulge is the maximum distance between lines that are perpendicular to the ground plane K that are tangent to the rear most point X and forward most point Y of the heel curve F. In the depicted embodiment a portion of the heel curve F is inclined forward at an angle θ that is greater than 10.0 degrees.
Referring primarily to FIG. 6 , the short heel girth AB as used herein refers to the dimension that passes through the heel point A and an instep point B. The heel point A as used herein is identified by the point upon which the girth dimension that passes through a point on the instep (e.g., point B) decreases as the point moves along the heel in either direction. The instep point B as used herein is defined by the point upon which the girth dimension that passes through a point on the heel (e.g., point A) increases as the point moves along the instep in either direction. The girth AB defines a plane referred to herein as plane I.
Planes E, G, V and W are defined herein to refer to planes that are parallel to the ground surface K, which the tread of the boot rests upon. See FIG. 6 . Plane V passes through point B. Plane E is 5 inches from point A in a direction L, which is a vertical direction perpendicular to plane K. Plane G is the plane that is 7.0 inches from point A in a direction L that is perpendicular to plane K. Plane H is a plane that intersects planes E and I through point B. Plane W is the plane that is 10.0 inches from point A in a direction L that is perpendicular to plane K.
In the depicted embodiment the girth in: plane I is less than 15.2 inches (e.g., less than 15.0 inches, about 14.7 inches, etc.), plane V is less than 11.8 inches (e.g., about 11.3 inches), plane H is less than 12.5 inches (e.g., about 12.0 inches), plane E is less than 11.7 inches (e.g., about 11.2 inches), plane G is less than 13.3 inches (e.g., 12.8 inches), and plane W is between 14.6-15.6 inches (e.g., 15.1 inches). The above dimensions of the size 9D boot define a boot that has a relatively close fit. It should be appreciated that proportionally different dimensions would result for different size boots (e.g., smaller boots such as size 7 or larger boots such as size 13).
Referring to FIGS. 7-10 , an alternative embodiment of the boot 10 is shown. The boot 100 has similar features to the boot 10 . One difference is that the boot 100 includes a fastening mechanism 102 at the top end of the boot. The fastening mechanism allows the upper end of the boot 100 to be easily enlarged to receive a user's pant leg and subsequently tightened over the user's pant leg. In addition to flexible zone 126 , the side panels 104 of the boot 100 are also configured to deflect when the user's heel enters and exits the boot. The deflection of the boot 100 is illustrated in FIG. 10 , wherein the dotted line 210 shows the boot in its undeflected state. In the depicted embodiment the flexible zone 126 comprises a polychloroprene material 412 covered by a flexible outer material. The flexible outer material is constructed of a low density molded blown rubber 400 (e.g., rubber having a density of less than 0.75 grams per cubic centimeters) cover by a four way stretch nylon material 402 . In the depicted embodiment the edges of the flexible outer material 404 , 406 extends under the vulcanized rubber periphery edges 408 , 410 of the flexible zone 126 . The flexible outer material provides improve durability and strength to the boot while still allowing the flexible zone 126 to flex as needed.
The present disclosure also provides a method of manufacturing the footwear. Referring to FIGS. 12-15 , in the depicted embodiment, the footwear is constructed around a last 200 . The last 200 is shaped to provide support to the footwear as it is constructed. In the depicted embodiment the last outer surface is configured to support substantially the entire inner surface of the footwear.
Since the footwear of the depicted embodiment is configured to fit relatively snugly around a user's foot and does not include a lacing system that allows the internal shape or volume of the boot to be increased or substantially changed, removal of the footwear from a last can be difficult as it involves substantially deforming the footwear (see FIGS. 14 and 15 ). The effort required to remove the footwear from the last can depend on a number of factors including, for example, the shape of the footwear relative to the shape of the last and the frictional characteristics between the surface of the last and the inner surface of the footwear.
To facilitate removal of the footwear from the last, the last of the depicted embodiment can include last removal features. For example, the last 200 includes portions that move relative to other portions. For example, the heel portion 202 can be configured to slide away from the main body portion 204 of the last 200 to facilitate removal of the footwear from the last 200 . In other embodiments, the last 200 can be configured such that other portions of the last move relative to the main body portion 204 of the last 200 (e.g., the forefoot portion 206 could be configured to pivot about point A and/or slide away from the main body portion 204 about line A-B).
In the depicted embodiment, removal of the footwear from the last can include the step of forcing air into the space between the last and the inside of the footwear. In one embodiment, the air is provided to outer surfaces of the last to blow off the inner surface of the footwear from the outer surfaces of the last, thereby preventing binding/sticking of the footwear to the last. The last can include a plurality of spaced apart air flow holes in some or all of the surfaces of the last. For example, air flow apertures could be provided on the outer surface of the last in the heel zone 208 , the toe and instep zone 210 , and/or the rear calf zone 212 to prevent binding of the footwear on the last in these areas. The locations of the air flow apertures can be arranged in areas where the footwear would otherwise catch or rub on the last as the footwear is removed from the last.
According to some embodiments, forced air (e.g., pressurized air) can be provided to the space between the inside surface of the footwear and the last to inflate at least a portion of the footwear. The inflating of the footwear deforms at least a portion of the footwear (i.e., expands a portion of the footwear), which can provide additional clearance between the footwear and the last as the footwear is removed from the last. In some embodiments, the air can be provided through the last itself via one or more air channels that are internal or external to the last. As discussed above, the air flow channels/apertures can be located in particular areas of the last. Alternatively, the air can be provided to a singular location in the last (e.g., the toe end 214 of the last). The air can be trapped between the last and the inner surface of the footwear by sealing the upper portion of the footwear against the upper portion of the last. The seal can be created by pressing the upper of the footwear against the last or by folding over the upper portion of the footwear to form a seal between the upper portion of the footwear and the last. While the footwear is inflated the footwear can be slid part way off the last.
In some embodiments, the forced air is provided at a high enough rate that sealing is not necessary to inflate the footwear. The air can be continuously forced into the space between the outer surface of the last and the inner surface of the footwear at a rate that is faster than that of the air escaping from the space, thereby causing at least a portion of the footwear to blow away from and/or inflate relative to the last. This configuration enables the operator to use both hands to pull the footwear free of the last. The flow can in some embodiments be controlled by a foot pedal. It should be appreciated that the various methods of removing the footwear from the last described above that involve forcing air into the last can be used together or separate from other methods of removing the footwear from the last.
According to some embodiments, slip sheets 310 can be provided between the inside surface of the footwear and the last to prevent binding of the inside surface of the footwear with the last. In the depicted embodiment, the slip sheet is provided on the rear surface of the last including the heel zone 208 and back of the calf zone 212 of the last. The slip sheet of the depicted embodiment is thin, low friction, heat resistant material ( 1/16″ Teflon® sheet). It should be appreciated that many other slip sheet configurations are possible. As discuss above, it should be appreciated that these and other methods of facilitating the removal of the footwear from the last can be used alone or in combination with other methods.
The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. | The present disclosure provides a slip-on boot with fit features that enable snug fit while still allowing for convenient foot entry and exit. Related methods of using and manufacturing a slip-on boot are also provided. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional application of U.S. patent application Ser. No. 12/355,660, filed on Jan. 16, 2009, which claims priority to U.S. provisional patent application Ser. No. 61/021,749, filed on Jan. 17, 2008, each of which is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates generally to a method and composition for patching air filter leaks, and, more particularly, to a method and patch for patching high efficiency air filter leaks without blocking significant parts of the filter and for allowing for active filtration after application of the patch to a leak or hole in the filter.
[0004] 2. Description of Prior Art
[0005] High efficiency air filters, commonly called HEPA or ULPA air filters, are widely used to produce particle free air in a variety of industrial and commercial facilities. The activity and processes taking place within many of these facilities will be adversely affected by contamination from particles in the airflow. These particles can include, for example, contaminants that adversely affect drugs produced in a pharmaceutical plant, cause a defect in a semiconductor wafer, or act as an undesirable foreign body in a drug compounded in a pharmacy.
[0006] Particle contamination mainly occurs due to leaks in filters that allow unfiltered air to pass through the filter, and affect the cleanliness of the facility. For this reason, leaks in HEPA and ULPA air filters are not acceptable, and hence are conventionally repaired or patched as shown in FIG. 1 (discussed below). Leaks in filters usually occur due to pinhole size blemishes caused during filter manufacturing or during use. Guidelines for acceptable repairing practice are given in most of the prevailing national and international standards (as should be appreciated by those skilled in the art, and need not be repeated herein).
[0007] As seen in FIGS. 1 a - b , HEPA and ULPA air filters 10 are constructed by pleating filter media 100 into an accordion style construction. FIG. 1 a shows a schematic face view of a cross section of an air filter 10 illustrating accordion style pleated air filter media 100 common to HEPA and ULPA air filters. The pleat shape and size as well as the method of holding the filter media 100 in place vary to accommodate the end use. The media 100 used in most HEPA and ULPA filters are made from micro fiberglass with fiber diameters as small as 200 nm and lengths of a few millimeters. These fibers are held together in a thin web by a small quantity of polymeric binder. The most common polymeric binder used for such media are thermosetting or thermoplastic acrylic ester latex polymers with other additives such as water repellants that are proprietary to the manufacturer of these media. These webs are about 0.5 mm thick and are usually made on a paper machine from a slurry of fibers and to which the polymeric binder is added either in the slurry or separately.
[0008] Typical fibrous structures of such filter media 100 and its multiple fiber layers are shown in magnified (scanning electron microscope (“SEM”)) views in FIGS. 2 a - b . Although each layer of the media appears to be inhomogeneous, a typical media is made up of several hundred layers of fibers. Thus, only a true blemish or pinhole will result in a leak that will require repair.
[0009] FIG. 1 b is an expanded view of a portion of the air filter 10 as shown in FIG. 1 a . FIG. 1 b illustrates a section which contains a suspected leak that needs to be patched. As shown in FIG. 1 b , current repair practice uses polymeric sealing or caulking compounds 120 to seal/patch the area around a suspected leak 110 . Conventional sealing compounds 120 include silicone and silicone based caulks, poly urethane, and other similar caulking compounds. Most of the time, since leaks are repaired in the field on installed filters, a caulk like consistency is required for the sealing compound to permit repairs overhead in ceilings, for example. In cases where it is practical, such as in a factory, a nearly liquid sealant is poured into the space between the folded filter media near the location of the leak. This blocking technique, while effective in sealing the leak 110 , blocks significant parts of the filter 10 thereby reducing the filter's effectiveness (dark patch 120 ). Further, the application of such sealing or caulking compounds 120 to seal leaks 110 in filters 10 already installed in ceilings, for example, often proves to be a cumbersome and inefficient procedure.
SUMMARY OF THE INVENTION
[0010] It is therefore a principal object and advantage of the present invention to at least partially seal (and preferably completely seal) air filter leaks without blocking significant parts of the filter, which would result in a reduction in the filter's effectiveness.
[0011] In accordance with the foregoing object and advantage, an embodiment of the present invention provides a sealant or patch that takes advantage of the fibrous nature of air filter media, and allows for active filtration through and around the leak. As compared with conventional sealing technology, the sealant does not completely seal or block a significant part of the filter (i.e., it is porous), thus allowing for this active filtration. The present invention also provides a method of sealing air filter leaks with the porous patch.
[0012] In accordance with an embodiment of the present invention, a sealant is provided which includes a mixture of a micro fiber glass, and a polymeric binder. The glass fibers can include, but are not limited to borosilicate fibers. The polymeric binder can include, but is not limited to, acrylic ester latex, urethane, and a moisture cure adhesive. The propellant can include, but is not limited to a compressed gas selected from the group consisting of air, nitrogen, and a non-highly flammable gas (as should be appreciated by those skilled in the art). The mixture can also include a solvent including, but not limited to, water, alcohol, and a mineral spirit. The mixture can be pressurized with a propellant within a housing including, but not limited to, an aerosol can. The mixture can contain less than 10% micro fiber glass, and up to 50% polymeric binder (preferably between 5-50%).
[0013] In accordance with an embodiment of the present invention, a method of sealing a leak in a portion of an air filter is provided. The method includes, but is not limited to, applying a sealant comprising a mixture of a micro fiber glass and a polymeric binder to the portion of the air filter which includes the leak, and allowing the sealant to cure. The mixture can optionally be pressurized with a propellant within a housing, such as an aerosol can. The mixture can further include a solvent. The sealant can be applied by spraying the sealant from the aerosol can on the portion of the air filter which includes the leak, or can be applied manually to the air filter. Curing can be facilitated by applying heat to the sealant, or by the application of air flow.
[0014] In accordance with an alternative embodiment of the present invention, a method of sealing a leak in a portion of an air filter is provided. The method includes, but is not limited to, applying a first mixture comprising a micro fiber glass and a solvent, wherein the mixture is pressurized with a propellant within a first housing, to the portion of the air filter which includes the leak; applying a second mixture comprising a polymeric binder and a solvent, wherein the mixture is pressurized with a propellant within a second housing, to the portion of the air filter which includes the leak; and allowing the first mixture and second mixture combination (i.e., sealant) to cure. The first and second housings can be aerosol cans. Curing can be facilitated by applying heat to the sealant, or by the application of air flow.
[0015] In accordance with an additional embodiment of the present invention, a method of sealing a leak in a portion of an air filter is provided. The method includes, but is not limited to, applying a sealant comprising a mixture of a micro fiber glass, a polymeric binder, and a solvent to the portion of the air filter which includes the leak, and allowing the sealant to cure. Applying the sealant may be accomplished by brushing the sealant over the portion of the air filter which includes the leak. Curing can be facilitated by applying heat to the sealant, or by the application of air flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
[0017] FIGS. 1 a - b are schematic views illustrating a cross section of an accordion style pleated air filter media common to HEPA and ULPA air filters, and conventional repairing or patching of air filter leaks.
[0018] FIGS. 2 a - b are magnified (scanning electron microscope (“SEM”)) views illustrating the fibrous structure of air filter media and its multiple fiber layers.
[0019] FIGS. 3 a - c are schematic scanning electron microscope views illustrating a cross section of an accordion style pleated air filter media common to HEPA and ULPA air filters, a sealant for air filter leaks (such as HEPA and ULPA high efficiency air filters), and the sealant's method of application, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0020] Reference will now be made in detail to the present preferred embodiments of the invention, wherein like reference numerals refer to like components, examples of which are illustrated in the accompanying drawing.
[0021] In accordance with an embodiment of the present invention, the sealant comprises a mixture made of three components including, but not limited to, a micro fiber glass, a sealing binder, and a solvent vehicle for the mixture. The sealant mixture can be pressurized with a propellant, as discussed further below.
[0022] The microfiber glass component can include, but is not limited to, borosilicate fibers similar to the composition and size of glass fibers used in most HEPA and ULPA filters (as should be appreciated by those skilled in the art), where the fibers typically range from about 80-1000 nm diameters and can be as long as 5 mm.
[0023] The binder component can be either an acrylic ester latex similar to the binders used in the media (as should be appreciated by those skilled in the art), or can be other polymeric material such as urethane, silicone, other adhesives or materials with special properties such as moisture cure adhesives that may offer advantages for use in the field (such as quicker setting times than the acrylic esters, or setting with moisture instead of heat, etc)
[0024] The primary fluid/solvent component for dispersing the micro fiber glass and binder mixture can be water, since glass fibers most readily disperses in low pH water. Since glass fibers typically used in filter media most readily disperse in cationic solvents, alternative solvents which are cationic or those that can be made cationic by addition of cationic materials, can also be used. These alternative solvents include but are not limited to, solvents such as alcohol, mineral spirits with cationic additives, etc.
[0025] The propellant can include, but is not limited to, air or any non-highly flammable gas commonly used for aerosol spray cans including nitrogen or carbon dioxide.
[0026] The sealant mixture noted above can have a low concentration of fibers to permit ease of application. In accordance with a preferred embodiment of the present invention, the aqueous mixture used for making the sealant mixture generally has less than 10% fiber. The binder content may vary, e.g., usually under 50%. This percentage of the binder depends on certain factors. For example, if the percentage of the binder gets to low, e.g., below 5%, the sealant may not be effective or as effective. On the other hand, if the percentage of the binder is too high, e.g., above 50%, the sealant may be too difficult to apply.
[0027] The sealant is prepared by creating and mixing a slurry of the micro fiber glass component (similar to those used in the air filter media) and the binder component, with a propellant. As shown in FIG. 3 c (discussed further below) an aerosol can 200 is charged with this fiber, binder, solvent mixture 210 , and pressurized with the propellant such as a compressed gas 220 (air, nitrogen, etc.).
[0028] Turning to FIGS. 3 a - c , a schematic face view of a cross section of an air filter (such as HEPA and ULPA high efficiency air filters), a sealant for air filter leaks, and the sealant's method of application are illustrated, in accordance with an embodiment of the present invention.
[0029] FIG. 3 a is a schematic face view of a cross section of an air filter 10 illustrating accordion style pleated air filter media 100 common to HEPA and ULPA air filters.
[0030] FIG. 3 b is an expanded view of a portion (portion “A”) of the air filter 10 as shown in FIG. 3 a . This portion illustrates a section which contains a suspected leak that needs to be patched, and is shown patched with the sealant mixture 210 as applied as a fine fiber spray 300 (shown lighter than 120 in FIG. 1 b ).
[0031] In accordance with an embodiment of the present invention, the sealing mixture may be applied two different ways. First, it can be applied by a pressurized aerosol can charged with it. FIG. 3 c is a transparent view of the aerosol spray can 200 including the compressed gas propellant 220 , and the sealant 210 (fiber, binder, solvent mixture) for air filter leaks (such as HEPA and ULPA high efficiency air filters). Since the fibers are small enough, the aerosol can 200 is sufficient to provide a fine fiber spray 300 of the fibrous mixture 210 . By directing this spray 300 at the leaks 110 in a filter, a fine layer of fibers will patch the leak 110 as shown in FIGS. 3 b . When the sealant or binder cures over time, the resultant patch can patch the leak with a porous sealant similar to the media with minimal or no blocking of the filter (see FIG. 3 b ), as compared with the current caulking technique shown in FIGS. 1 a - b . In addition to a blockage free seal of the leak, the use of aerosol cans can be a more convenient and less cumbersome means for fixing leaks in the field.
[0032] In accordance with an alternative embodiment of the present invention (not shown), an aqueous solution of the fibers with solvent and pressurized with a propellant, and of the binder with solvent and pressurized with a propellant, can each be independently applied by pressurized aerosol cans charged with them, respectively. In this case, the area to be repaired 110 will be treated with multiple aerosol cans (as opposed to a single aerosol can 200 , as shown in FIG. 3 c ), i.e., alternately with the fiber mixture and the binder, similar to multiple coats of spray painting. In both cases, multiple coating of the mixture may be required much like multiple coats during common spray painting.
[0033] By appropriate choice of the binder, one may alter the rate of curing for the patch with or without heat. For example, in accordance with an embodiment with the present invention, once the repair sealant mixture 210 has been applied (e.g., as a spray), the resultant patch can be cured either by heat if the acrylic esther latex is used, or by humidity or ambient air depending on the type of adhesive binder used. Acrylic binders require heat to cross link and cure and can be achieved by hot air guns. The heat will also evaporate any water associated with the mixture that is deposited on the filter. Where heat is not allowed for other operational reasons at the installation, other adhesives can be used. In this case, the moisture can be removed by normal air flow, albeit at a potentially slower rate.
[0034] In accordance with an alternative embodiment of the present invention, where a spray is not acceptable, the same fiber and binder slurry (with solvent but without propellant), may be brushed over the leak 110 for a similar blockage free sealing of leaks 100 . Also, where the leaks 110 in the filter are obvious, the fiber and binders may be applied over the leak by means of a brush or sponge. As with the spraying described above, the fibers and binders may be applied as one mixture or separately.
[0035] In yet another embodiment of the present invention where a pressurized spray is not acceptable or desirable, the fiber and binder slurry (with solvent but without propellant), may be manually applied over the leak 100 for a similar blockage free sealing of leaks 100 . This includes any known method or means of manual application, including using a brush, sponge, syringe, or squeeze bottle, pouring the slurry over the leak, or any other mechanism of non-propellant manual delivery. As with the spraying described above, the fibers and binders may be applied as one mixture or separately.
[0036] While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawing and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claimed invention.
DEFINITIONS
[0037] The following definitions are provided to facilitate claim interpretation:
[0038] Present invention: means at least some embodiments of the present invention; references to various feature(s) of the “present invention” throughout this document do not mean that all claimed embodiments or methods include the referenced feature(s).
[0039] First, second, third, etc. (“ordinals”): Unless otherwise noted, ordinals only serve to distinguish or identify (e.g., various members of a group); the mere use of ordinals implies neither a consecutive numerical limit nor a serial limitation.
[0040] To the extent that the definitions provided above are consistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall be considered supplemental in nature. To the extent that the definitions provided above are inconsistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall control. If the definitions provided above are broader than the ordinary, plain, and accustomed meanings in some aspect, then the above definitions shall be considered to broaden the claim accordingly.
[0041] To the extent that a patentee may act as its own lexicographer under applicable law, it is hereby further directed that all words appearing in the claims section, except for the above-defined words, shall take on their ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), and shall not be considered to be specially defined in this specification. In the situation where a word or term used in the claims has more than one alternative ordinary, plain and accustomed meaning, the broadest definition that is consistent with technological feasibility and not directly inconsistent with the specification shall control.
[0042] Unless otherwise explicitly provided in the claim language, steps in method steps or process claims need only be performed in the same time order as the order the steps are recited in the claim only to the extent that impossibility or extreme feasibility problems dictate that the recited step order (or portion of the recited step order) be used. This broad interpretation with respect to step order is to be used regardless of whether the alternative time ordering(s) of the claimed steps is particularly mentioned or discussed in this document. | The present invention relates generally to a patch including a micro fiber glass and a polymeric binder, where the mixture forms an in situ porous patch that allows for active filtration after application to a leak or hole in an air filter. The mixture can be pressurized with a propellant within a housing prior to application to a leak or hole in an air filter. The mixture can also be applied manually to a leak or hole in an air filter, without the need to be pressurized with a propellant within a housing. | 2 |
BACKGROUND
1. Field of the Invention
The present invention relates to a method for covering a substrate with an essentially biodegradable protein foam barrier. More particularly, the present invention relates to a method for providing protein containing foam coverings to substrates such as landfills, sewage holding tanks, contaminated soil sites, sludge deposits, compost piles and the like, to effectively form a semi-permanent foam layer between the exposed surfaces of such substrates and the environment surrounding them.
In an alternative embodiment the present invention also relates to a method for providing a foam covering to substrates such as buildings and other natural and artificial structures to protect such substrates from adverse environmental conditions such as polluted air or water, insects, extreme hot and cold temperatures, toxic vapors and the like. For example, it is often desirable to provide a protective foam barrier layer on the exposed surfaces of buildings or houses thought to be in the path of forest or brush fires.
In another alternative embodiment the present invention can be used to enhance the action of "oil-eating" bacteria used in the clean-up of petroleum spills by acting as a medium to hold the bacteria in contact with the spilled oil.
Although the method and apparatus described herein may be readily applied to all of the substrates recited above, for simplicity and convenience, this invention will be described in connection with its application as a covering for a landfill waste site. In this application the protein containing foam is used as a substitute for the dirt cover customarily applied to such landfills. It is to be understood, however that the description of this invention as applied to a landfill is merely intended in an illustrative sense and is not to be limited to a single application.
2. Background of the Invention
In the United States, the dumping of waste as in commercial and municipal landfills is regulated by state, local and federal regulations which generally require that the surface of the landfill, containing the day's deposit of waste, must be covered on a daily basis. Typically, such regulations require that the waste on the exposed surface of the landfill (the working face) must be covered by a six inch layer of earth. These regulations are designed to reduce the spread of disease and trash by insects, vermin, birds, etc. by limiting their access to the garbage. Covering the day's refuse also serves to reduce odor and polluting vapors and fumes.
This requirement for covering the day's refuse places a heavy burden on the landfill operators by requiring a substantial amount of labor and equipment to accomplish the daily covering operation. The requirement is also costly to the environment as the available landfill space is rapidly depleted. The addition of six inches of earth daily effectively uses up a great deal of available space within the landfill which could otherwise be used to contain more waste. With available space being rapidly depleted and land prices increasing, this will certainly become an even greater burden in the future.
This problem has been previously addressed in U.S. Pat. Nos. 4,421,788 to Kramer and 4,519,338 to Kramer et al. which disclose use of a hardenable plastic foam in place of the soil. The processes described in these patents claim it is possible to reduce the thickness of the cover to approximately one to two inches or perhaps slightly less while still achieving an adequate cover to provide the protection required. While a reduction in the amount of wasted landfill area and the labor required for application of the covering is reportedly achieved, these patents make no mention of the environmental effects of the hardenable foam itself. For example, these disclosures are silent as to how long it takes for the foam itself to break down, or as to how much valuable landfill space remains occupied by the hardened foam, or the effect the hardened foam has on drainage parameters within the landfill. Although a great improvement in the amount of waste landfill volume has been achieved, further reduction is desirable as well as improvement in the biodegradability of the foam.
Protein based foam has been used for fire fighting and treatment of hazardous material spills in the past. It is known to use xanthan gums as an additive to such foams as for example described in U.S. Pat. No. 4,424,133 to Mulligan. However, the foam described in this patent is not suitable for use as a temporary cover for the substrates described herein because it lacks the long term stability and is less resistant to rain and wind.
The present invention addresses these needs by providing an improved method and apparatus for covering substrates such as landfills using a protein foam. In addition to the foam composition being readily biodegradable, this composition may actually add to the nutrient value of the soil and help promote biodegradation of the landfill waste as well as adding substantial moisture and some aeration. In essence, due to the unique characteristics of the composition described herein, a foam is produced which is capable of working in harmony with nature.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method for use in covering the surface of a substrate, such as a landfill, sewage holding tank, contaminated soil, hazardous waste or sludge deposit, compost pile and the like.
It is a further object of the present invention to provide an improved method for applying a protective covering to buildings and other artificial and natural structures.
It is a further object of the present invention to provide a protein based foam for use as a covering or barrier which lasts for up to several days before collapsing and ultimately takes up essentially no space.
It is another object of this invention to provide a protein foam cover which is easy to apply such that reductions in labor can be achieved which are similar to those obtained using prior art hardenable foam application methods.
It is still another object of this invention to provide a protein foam cover that is non-polluting and non-film forming and does not leave a permanent residue.
It is still another object of the present invention to provide a protein containing formulation optionally in the form of a concentration which can be mechanically manipulated to produce various dense foam blankets with a life of up to five days or longer with resistance to rain and wind.
These and other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the following description of the invention.
In one embodiment the present invention provides a method for covering a substrate having one or more surfaces exposed to the environment to provide a temporary or semipermanent foam barrier layer between the substrate and the environment. This method comprises in combination, the steps of providing an aqueous solution or dispersion containing an essentially biodegradable protein base material and one or more foam stabilizing agents; mixing this solution or dispersion with air (as by mechanical manipulation) to produce a foam; and thereafter applying the foam to the exposed surface or surfaces of the substrate to be covered. The foamed surface thus produced may be leveled to produce a substantially uniform layer thickness.
In still another embodiment a method and apparatus are provided for treating landfill waste wherein a protein based solution, preferably diluted from a concentrate using the landfill's own treated leachate, is mixed with air in a foam production nozzle and then spread to an approximately uniform thickness over the surface of the landfill. The foam is spread by an applicator followed by an integral leveler which scrapes the surface of the foam to produce a relatively uniform foam layer approximately four to six inches deep. The protein foam layer can be formulated to last for several days and serves to keep animals out of the refuse and reduces emission of vapors while eliminating the need for a daily cover of earth over the refuse. This provides substantial economic benefits while reducing the wasted volume of the landfill previously occupied by soil to a negligible amount.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawing/figures.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a side view of a foam application apparatus of the present invention.
FIG. 2 shows a top view of the foam application apparatus of FIG. 1.
FIG. 3 shows a top view of a turbulator and nozzle assembly used for foam production.
FIG. 4 show a side view of a portion of the assembly of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
All percentages or parts measurements discussed herein are by weight unless stated otherwise.
In the present invention, a protein based foam is used as a cover material for the so called "working face" of a landfill or other surface. The preferred foam is made from concentrated solution derived from a hydrolysed protein concentrate base. Such hydrolysed protein bases are well known in the fire fighting foam art. They are produced by hydrolysing keratin containing materials such as animal hooves and horns, fish scales, hair or feathers. Albumen, bloodmeal, dairy derived proteins or proteins from vegetables such as soy bean meal, etc are other sources of proteinaceous starting materials. One or more foam stabilizing agents is added to enhance the bubble stability of the foam. Various foam stabilizing agents may be used such as polyvalent metal salts, gums, polysaccharides, soluble starches, starch polymers and deliquescents. Freezing point depressants such as polyglycols or other glycol ethers may be added in small quantities to retard freezing of the concentrate in colder weather but are not necessary. A concentrate of this mixture is added to water at the time of use, or possibly as much as a few hours before, to produce a foam solution.
Unlike the plastic foams which have been used for such applications as insulation, the present foam is not a plastic, gelled or cured foam product. It is derived from natural animal wastes rich in protein. Moreover, it contains no phosphates, mercury or other materials identified as contaminants or pollutants, and is essentially biodegradable.
The proteinaceous materials may be broken down into peptides, polypeptides and salts of amino acids via alkaline hydrolysis with lime or caustic sodium hydroxide (NaOH). The resulting protein hydrolysate is a major component of the foam concentrate. Other methods for producing the protein hydrolysate may equally well be used.
Because the naturally derived protein base has been shown to be non-toxic, non-polluting and completely biodegradable, it is believed to be a superior covering material for landfills. Because of these attributes, the use of such foam is perceived to be more biologically compatible with nature, thus overcoming the otherwise environmentally objectionable aspects normally associated with landfills, municipal waste and land reclamation projects in general.
The basic composition of the protein foam concentrate of the preferred embodiment is shown in Table 1 below:
TABLE 1______________________________________COMPONENT APPROX. PERCENTAGE______________________________________protein hydrolysate 35-70(concentrate)polyvalent metallic salt 1.0-2.5foam booster 3-7bactericide 0.1-0.2dispersant 10-14water balance______________________________________
with all percentages being by weight unless otherwise stated.
A more preferred formulation of the foam concentrate is shown in Table 2 below:
TABLE______________________________________COMPONENT PERCENTAGE______________________________________protein hydrolysate 35-70(concentrate)iron salt (Ferrous Chloride) 1.0-2.5foam booster 3-7bactericide 0.1-0.2sodium lignosulfonate 10-14water balance______________________________________
A still more preferred composition of the foam concentrate is shown in Table 3 below:
TABLE 3______________________________________COMPONENT PERCENTAGE______________________________________protein hydrolysate 61.70(concentrate)iron salt (Ferrous Chloride) 1.80hexylene glycol 3.24Nipacide BCP 0.18sodium lignosulfonate 12.98(Marasperse N-22)water 17.80______________________________________
The protein hydrolysate is commercially available as a 35-50% concentrate having a pH from approximately 7 to 8 and a specific gravity of 1.148 to 1.152. It can be obtained from any of a number of manufacturers of protein based fire fighting foam or it may be hydrolyzed, as previously described, from the protein found in animal hooves, horns, etc. The concentrate can be made, for example, by lime hydrolysis.
A polyvalent metal salt is added preferably to provide a level of foam stabilization by bonding the reactive sites on the protein residue, gums or other polyelectrolytes in the formula. Ferrous chloride is the agent of choice as it is relatively inexpensive and is not considered to be environmentally hazardous.
Desirably any number of known freezing point depressants may be added to the basic formulation if needed. In particular, polyalcohols, polyglycol ethers, glycols, etc. Reference to freezing point depressants is only for protection of the concentrate. Hexylene glycol is preferred and is added primarily as a foam booster, although it also serves as a freezing point depressant. Other foam boosters suitable for use include diethylene glycol, dipropylene glycol and glycol ethers such as 2-ethoxyethanol, 2-butoxyethanol and 2-(butoxyethoxy) ethanol.
Preferably, a bactericide is added as a preservative to prevent the decomposition of the foam concentrate by bacteria. Any number of bactericides may be used such as Kathon, available from Rohm & Haas Co., Nipacide BCP or Nipacide MX available from Nipa Laboratories, and the proportions adjusted according to need. The proportion recited in Table 3 is suitable when the bactericide used is Nipacide BCP. Because protein hydrolysates are excellent nutrient sources for microbiological life forms, a low level toxicity biocide should be added to preserve the concentrate. However, when the concentrate is diluted for use, the concentration of the biocide becomes so small that it can no longer provide the preservative effect. Thus, long term holding of premixed solution is not advised.
Many commercially available dispersants may also optionally be added to enhance the dispersion of ingredients and to provide additional foamability and foam stability. Sodium lignosulfonate sold as Marasperse N-22, available from Daishowa Chemicals is preferred, but other dispersants such as lignosulfonate and alkyl naphthalene sulfonates may also be used.
The basic foam concentrate formula is diluted to approximately 2.0 to 3.5% with water prior to turbulation to produce foam. The preferred dilution is approximately 3% but a relatively wide range is functional. At 3% (i.e. 97 parts by volume of water), dilution, the solution produces a high quality foam which is highly cost effective.
To the above basic formula, an additional foam stabilizer may optionally be added to improve the resistance to rain and/or wind and to improve the long term (measured in days) stability of the foam blanket when applied. A number of materials can be used for this purpose. For example, the addition of a polysaccharide xanthan gum commercially available under the trade name Rhodopol 23, manufactured by Rhone-Poulene, can increase the foam stability and minimize surface erosion of an aging foam blanket by wind. The basic formulation of the foam with the addition of a 0.08% portion by weight of xanthan gum may result in an increase in the life of the foam blanket from approximately 48 hours to beyond 72 hours. Suitable ranges of xanthan gum are from roughly 0.03 to 0.1% by weight depending upon the stability of the foam desired. Optimum, foam stability appears to occur with the addition of approximately 0.05 to 0.1% xanthan gum.
With certain xanthan gums, there is a possibility that the solution will gel if the gum is added and allowed to set for too long. Therefore, it is preferable to add the xanthan gum to the mixture just prior to use.
In place of the xanthan gum, other known humectant gums, thickening agents and foam stabilizers may be used. Examples of potential candidates are such water soluble polymers as Macol 108 POE/POP block copolymer, Peg 600 Polyoxyethylene Monolaurate and Tetronic 904 POE/POP block copolymer. Optionally, foam stabilizers such as polyacrylamide, polyacrylamide/vinyl acetate - methyl pyrrolidone copolymer, polyvinyl alcohol and water soluble cellulose and derivatives thereof may be added directly to the concentrate. Suitable concentrations in the range of about 1% to 20% are desirable when these agents are added to the concentrate. After dilution , they will be present in the solution in the range of about 0.1% to 2%.
In field tests, a three percent solution of foam applied to a thickness of six inches lasts approximately one to three days without a foam stabilizer. By adding 0.08% xanthan gum, the foam lasted five to seven days under similar environmental conditions. The stabilized foam produced a thick stable cover capable of supporting substantial weight. Wind and rain resistance properties were also improved.
In a preferred embodiment of the present invention, the water used to mix with the concentrate to produce a dilute solution is actually a potable water. The treated leachate of the landfill singly or mixed with potable water may be suitable. Many modern landfills have a sealed bottom to prevent waste from passing into the groundwater below thus causing pollution. In such an arrangement, it is common to drain off the liquids (the leachate) obtained from the landfill, including substances washed down by rain water and the like, into a holding reservoir where the leachate is treated. The most common form of treatment is simply to aerate the leachate. In other landfills, more elaborate purification of the leachate is performed. Although in some circumstances the leachate may contain materials which will impair or perhaps even totally inhibit the performance of the foam, this can be determined experimentally to determine the extent to which such leachate can be used.
By using the leachate reservoir as a source of the water for dilution of the concentrate, several advantages are achieved. The leachate will likely contain numerous microorganisms of whichever strains tend to thrive in the environment of the particular landfill at hand. By using this leachate and reintroducing the microorganisms suspended in the foam blanket, it is believed that enhanced decomposition of the waste material will be achieved. In addition, the natural selection process which determines which strains of microorganisms thrive in a particular landfill environment will provide a tailor made culture which is more likely to survive in the landfill to do its job. While, presumably, such microorganisms could be introduced into the foam compositions artificially, there is a lower probability that they could survive unless they were properly selected for the particular environment.
Further advantages lie in the use of a supply of water which is not otherwise generally useful thus conserving the supply of fresh water and recycling the leachate. This additionally serves to reduce the cost of supplying the water to dilute the concentrate and recycles the water to the landfill for further natural biological cleansing. In some instances, the leachate will likely degrade performance of the foam blanket. This can be combatted in many instances by either adding foam stabilizers, diluting the leachate with fresh water, increasing the concentration of foam concentrate, or some combination of the above.
The effects of the variation of the ingredients and application methods can be better appreciated upon review of the following examples. Examples 1 to 6 were conducted at an actual operational landfill under similar weather conditions.
EXAMPLE 1
Five gallons of foam concentrate were added to 160 gallons of water to produce a 3% solution by volume for application to a landfill. The solution was mixed by recirculation for approximately five minutes and then turbulated to produce foam using a pump pressure of 125-140 psi for the liquid injection and 90 psi for the air. At the foam production turbulator - nozzle, equal pressures of 75-90 psi for both air and liquid were maintained. The nozzle was packed with small 1/2" plastic spheres and 3/8" Raschig rings and stainless steel shavings and delivery of the foam was through a duck-bill shaped spreader. The foam exited the nozzle as a broad ribbon-like band that was easily applied and folded. Foam depth depended upon the foam velocity from the nozzle and the speed that the nozzle is moved. Most deposition was approximately 6 inches thick. The foam appeared creamy as shaving cream and the useful life of the foam blanket was approximately 48 hours.
EXAMPLE 2
Five gallons of foam concentrate were mixed with 140 gallons of potable water and 20 gallons of 0.5% xanthan gum to produce a 3% solution with 0.0625% gum stabilizer. The mixture was thoroughly mixed by recirculation and applied under the same conditions as example 1. The foam appeared similar to that of example 1. After 48 hours, the surface had darkened in color but had not yet eroded significantly. The foam was less friable at the surface. Five days later (120 hours) a significant foam blanket was still in place with a depth of approximately 4 inches. The foam was still moist and the surface intact. Thus, the addition of the xanthan gum as a stabilizer at least doubled the life of the foam blanket in this test.
EXAMPLE 3
In this example, the landfill leachate reservoir was used as a source of 160 gallons of treated (by aeration) leachate (water). This was mixed with 5 gallons of foam concentrate, recirculated to mix and applied as in example 1. The appearance of the foam initially appeared normal, but within 3 to 4 hours of application, run off drainage solution was noted. This did not occur with example 1 or 2. 24 hours later the foam blanket had shrunk and the residue was dry and powdery and easily collapsed in the wind. This solution may be acceptable where short foam life can be tolerated such as for an overnight blanket. Additional life may be possible with addition of foam stabilizers. Different results can be expected depending on the composition of the leachate.
EXAMPLE 4
Four gallons of foam concentrate were added to 150 gallons of potable water and 5 gallons of Chubb National Foam Universal Foam Concentrate (a concentrate used as a fire fighting foam and for hazardous material spill applications) to produce a 6.25% solution. The solution was mixed and applied to a landfill as in example 1. The resulting foam blanket had a creamy texture but was more elastic in movement and seemed to set more slowly. The foam tended to flow laterally to self level and exhibited normal expansion. Drain off was evident in 3-4 hours by edge wetting. After 24 hours, the surface was dry and powdery on the surface with a moist interior. Wind erosion was noted, but this formulation is adequate for a 24 hour blanket.
EXAMPLE 5
A 6.25% solution was prepared using 75 gallons of potable water with 2.5 gallons of concentrate and 2.5 gallons of Chubb National Foam Aer-O-Foam XL-3 (a fluoroprotein fire fighting foam concentrate). The mixture was mixed and applied as in example 1. This formulation provides an excellent 24 hour blanket.
EXAMPLE 6
A 6% solution was prepared using 155 gallons of potable water and 10 gallons of Chubb National Foam Aer-O-Foam XL-3. The mixture was mixed and applied as in example 1 and provided a blanket with an appearance similar to that of example 1 but which set more quickly and was stiffer (in part because of the higher concentration). The blanket lasted for about 24 hours but at that point the top surface was dry and drainage was noted. Rain simulated by gentle fog spray of water collapsed the 24 hour blanket.
EXAMPLE 7
The composition of Table 3 is diluted with water to a concentration of 3% and foamed by use of a CAFS (compressed air foaming system) machine such as those in common use in wildland fire fighting . These machines deliver the foam through a hose with sufficient velocity that the foam may be projected as far as 100 ft. The foam so generated is of a stiff consistency and adheres to vertical surfaces. Thus it is used to cover walls and roofs of buildings and other structures to protect them against ignition from the radiant heat and firebrands generated by the passage of the fire front of forest or brush fires. This protection lasts for up to 48 hours. Similarly, such foam is used to coat vegetation for the establishment of "wet lines" to prevent the spread of forest or brush fires.
EXAMPLE 8
Foam generated in the manner described in example 7 is also used to coat the working face and excavated contaminated soil in hazardous waste site clean-ups to prevent the release of hazardous and nuisance vapors. Optionally, the working face may be coated in the manner described in examples 1 and 2. The working life of the foam cover is 24-48 hours. This life is extended by the addition of previously described foam stabilizers to the foam solution. Prior to transportation of the contaminated soil by truck or rail car, the surface of the soil is coated with 6-8 inches of foam to prevent the release of vapors enroute.
EXAMPLE 9
The foam of examples 1, 2, or 7 is applied to windrows of contaminated soil excavated from hazardous waste cleanups where the soil is undergoing bioremediation. The foam prevents the release of vapors and odors, maintains an effective moisture content in the windrows and supplies a nutrient broth to the bacteria as it breaks down.
EXAMPLE 10
Bacterial cultures of the type which are used to break down spilled crude oil or other forms of petroleum are mixed with a 3% solution of the composition of Table 3 in either fresh or sea water. The resultant solution is foamed by the method described in example 7 and projected on to the surface of the spill. The foam acts as a broadcasting medium to aid in even distribution of the bacteria and enhances the effectiveness of the bacteria by holding them in intimate contact with the spilled petroleum. The protein content of the foam also serves as a source of nutrients to the bacteria.
The above examples demonstrate that by blending the basic formula and/or other protein foam concentrates it is possible to engineer a foam with varying properties such as service life, cost, etc. Further, the actual mechanical manipulation of the foam solution and air to produce the foam blanket can have substantial impact on the life of the blanket. For example, if the foam is turbulated and applied directly to the surface without being sprayed over substantial distances, the foam tends to last significantly longer due to the energy being expended to propel the foam being better utilized to better mix the foam solution with air. Also the propelling of the foam may actually weaken the blanket in some manner.
The process may be carried out using a pre-mix batch, applied by any conventional compressed air foaming system or by a turbulator foam generator nozzle. However, systems using precise proportioning techniques may also be used to balance the foam concentrate with the dilutant. By using proportioning techniques, there is no left over premix to dispose of and thus these techniques are generally preferable.
The performance of the system is based on composition(s) of the foam concentrate(s) and the mechanical manipulation of the foam solution. Ideally, the foam solution conversion which optimizes air (or gas) entrained and minimizes unconverted solution or interstitial liquid gives best results. Under these conditions, wet densities should range from approximately 3 to 5.2 lbs / cubic foot with expansions of from 20 to 1 through 12 to 1 respectively. For example, a foam blanket 6 inches in thickness has a wet density of 1.5 lbs to 2.6 lbs / square foot depending on expansion.
Foam stability is a direct function of bubble size and consistency of bubble size. A homogeneous foam that would allow formation of polyhedrons having flat faces in the shape of a pentagon, such as dodecahedron would be ideal. In practice, using the production method to be described, nearly uniform bubble texture is observed. Bubble sizes of 0.050 to 0.25 inches but in any case less than about 0.5 inches in diameter appear to give the most acceptable blanket performance. Consistency in bubble size is more important than actual size, but for the solutions of the present invention, smaller bubble sizes are generally better. Unlike insulating foams and the like where dry densities yield light cellular structures, the wet density of landfill foams, hence small bubble sizes, is more desirable because it adds mass to hold down debris and resist surface erosion by moderate winds and holds water.
Turning now to the drawing in which like reference numerals designate corresponding parts throughout the several figures thereof, and in particular to FIG. 1 in conjunction with FIG. 2, a vehicle mounted proportioning apparatus used for application of the foam cover of the present invention is shown. In this embodiment, the foam spreading device is mounted to a bulldozer or similar land vehicle such as a Caterpillar 40" triple grouser track loader undercarriage or other low profile wide tread vehicle for traveling over the compressed surface of the landfill (working face) 10. Such a vehicle is shown as 12 in the figures. In some embodiments of the present invention, as in this figure, the vehicle may be a special purpose vehicle used primarily for application of the foam. In other embodiments, the foam production equipment may be temporarily mounted in the bucket of a bulldozer or similar machine or may be towed behind the vehicle. The forward direction of movement of the vehicle is shown by the arrow in FIG. 1 and FIG. 2.
The bed 14 of the vehicle 12 carries an air compressor 16 (or possibly a tank of compressed air) driven by a motor 18 to provide air for mixing with the foam solution. The water or leachate is carried in a plurality of tanks 20. Solution is made from the above foam concentrate and water in a proportioner. Total tank capacities of approximately 1000 to 3000 gallons are generally satisfactory.
A water pump 22, preferably a positive displacement water pump, pumps the water from the tanks 20 into a proportioner and then to a manifold feeding a plurality of turbulators 24 and foam production nozzles 26 mounted at the rear of vehicle 12. The water pump 22 may be driven by an independent power source such as an electric generator or may tap into the power train of the vehicle to operate the pump. An oil recovery unit 28 is used to recover oil from the air compressor in a known manner. A pair of tanks 30 to carry foam concentrate are mounted to either side of the compressor 16 and motor 18. The vehicle's engine 32 and associated hardware is positioned at a central area of the vehicle 12.
The water or leachate and foam concentrate may be mixed in a known manner using known proportioning techniques such as those used in proportioning foam generation equipment used for fire fighting to produce the proper percentage solution. Stabilizer can be added to the water or leachate, or if the stabilizer does not cause long term storage problems, it can be added or provided in the concentrate. The solution is then supplied to a manifold connecting a plurality of turbulator--nozzle assemblies. In the embodiment shown, seven such turbulator--nozzle assemblies are connected together on 20 inch centers to provide a path of foam approximately 12 feet wide. When the foam is dispensed from the spreader portion 26 of the nozzle, it is wiped to a consistent height by a plastic (or metal or other suitable material) screed 34.
The turbulator--nozzle assembly of a preferred embodiment is shown in FIG. 3 and FIG. 4. This assembly is made of 3/8" thick standard metal or steel tubing which is shaped and welded into the configuration shown. The spreader 26 is approximately 15 inches in dimensions L1 and L2 and tapers to an opening 40 of about 13/8" at the tip. The top 42 of the spreader is approximately 6" square. Top portion 42 is mated to the turbulator 24 portion of the turbulator-nozzle assembly which is made of three series connected sections.
The bottom-most section 46 is a Raschig ring packed turbulator made of a pipe of approximately 4" diameter which is packed with 3/8" OD×3/16" ID×3/8" long plastic (polypropylene) Raschig rings. At both ends of the Raschig ring turbulator 46 is a screen with mesh small enough to contain the Raschig rings. This turbulator is approximately 12 inches in length.
The middle section 48 is a sphere packed turbulator which is approximately 6 inches in length. This section is similarly made of pipe of approximately 4 inch diameter which is packed with 1/2" or 3/8" polypropylene spheres. Once again, screens are used to contain the spheres of the turbulator.
The uppermost section 52 forms a turbulator and is made of narrower diameter pipe having a one inch inner diameter and approximately 6 inches length. This section 52 is loosely packed with stainless steel turnings such as those used for scouring pads (e.g. Chore-Boy™ brand scouring pads).
The upper end of the packed turbulator 52 is attached to a mixing chamber 56. Air and foam solution are injected into this mixing chamber 56 through internal orifices (not shown). The solution pressure at this point is approximately 80-95 psi with a feed rate of 12-16 gallons of solution per minute per nozzle. Air is injected at approximately 80-95 psi at this point to provide an expansion of approximately 12-16 times.
In operation, the foam solution and air mixture are delivered to the turbulator - nozzle assembly where three stages of turbulation take place. First in the steel turnings packed turbulator 52, second in the sphere packed turbulator 48 and finally in the Raschig ring turbulator 46. Finally, the foam is delivered to the duck bill shaped spreader 26 where it comes out and is spread over the landfill. The thickness of the blanket can be controlled by the speed of the vehicle, the height and rigidity of the screed 34 and the delivery rate of the foam.
To obtain a six inch thick blanket for landfill application, the solution is applied at a rate of approximately 300 to 500 square feet per 100 gallons of 3% solution for a covering of approximately six inches in depth. The trash should preferably be compacted prior to application of the foam in order to more easily cover the surface. This is generally no problem since the surface of the landfill is more or less constantly being worked as new trash is added to maximize use of the landfill. If a premix process is used, just prior to application of the foam, the solution is mixed from a concentrate with an appropriate amount of water to form a solution of approximately 3% by volume (that is 3 parts of the concentrate is diluted with 97 parts of water by volume to produce a 3% solution. The stabilizer is added and this solution is mixed and then applied as described above. The protein foam remains soft and foamy for some time after application which allows for some settling into cracks and crevices which form in the surface of the working face. When more refuse is to be added, it is simply placed on top of the layer of protein foam which essentially completely collapses under the weight of the refuse and the equipment used to manipulate the refuse. The foam blanket therefore ultimately occupies essentially no space within the landfill.
The mechanical manipulation of the foam mass as described is accomplished by metering compressed air (or other gas) to a mixing point where metered foam solution is likewise directed. Sizing the orifices of the applicator 28, or using valves, to maintain and balance the operating pressures provides optimum air-solution mixture.
The foam coating produced by this process is readily degradable and may actually improve the degradation of other materials in the landfill. The foam can be formulated to remain soft throughout its useful life and therefor provides little in the way of a physical barrier to wildlife, but nonetheless seems to provide enough of a barrier to effectively thwart birds and other wildlife. The foam is relatively harmless to wildlife if ingested or breathed in small quantities and birds appear to be repelled somewhat by it.
Thus it is apparent that in accordance with the present invention, an improved apparatus and method that fully satisfies the objectives, aims and advantages is set forth above. While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, variations, modifications and permutations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, variations, modifications and permutations as fall within the spirit and broad scope of the appended claims. | A method and apparatus for covering substrates such as landfills, sewage, contaminated soil, sludge deposits, compost piles and the like. A protein based solution, preferably mixed from a foam concentrate, is mixed with air in a foam production nozzle and then spread to an approximately uniform thickness over the surface of the substrate.
In an alternative embodiment the present invention also relates to a method for providing a foam covering to substrates such as buildings and other natural and artificial structures to protect such substrates from adverse environmental conditions such as polluted air or water, insects, extreme hot and cold temperatures and toxic vapors or substances. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to processes for making silylisocyanurate, e.g., 1,3,5-tris[(trialkoxysilyl)alkyl]isocyanurates.
[0002] Silylisocyanurate has utility as an accelerator or promoter for adhesion of room temperature vulcanizable organosiloxanes and silane modified polymers, as an additive for organosiloxane compositions suitable for fiber treatment and in automotive coatings.
[0003] U.S. Pat. No. 3,598,852 describes a process for making silylisocyanurate in which a haloorganosilane intermediate is reacted with a metal cyanate in the presence of a high boiling polar solvent such as dimethylformamide. Subsequently, the polar solvent is removed by vacuum stripping. However, the solvent is toxic and difficult to remove.
[0004] U.S. Pat. No. 4,880,927 describes a process for preparing silylisocyanurate in which the silylisocyanate is thermally treated or heated for cyclization to the trimer in the presence of a strongly basic catalyst such as alkali metal hydroxides or alkoxides. However, when this process is employed for the preparation of silylisocyanurate, it requires the isolation of toxic isocyanate and results in a highly colored product.
[0005] U.S. Pat. No. 5,218,133 describes the cracking of silylorganocarbamate in the presence of cracking catalyst under moderate heating and subatmospheric pressure to a non-isolated silylorganoisocyanate intermediate and by-product alcohol, the silylorganoisocyanate then undergoing trimerization in the presence of trimerization catalyst in situ to provide silylisocyanurate. Typical cracking catalysts for this process include aluminum, titanium, magnesium and zirconium alkoxides such as aluminum triethoxide which is indicated to be preferred and tin carboxylates such as dibutyltin dilaurate, dibutyltin diacetate and stannous octoate which are indicated to be preferred. Trimerization catalysts employed in the process of U.S. Pat. No. 5,218,133 include sodium methoxide and the alkali metal salts of organic acids such as the sodium, potassium, lithium and cesium salts of glacial acetic acid, propionic acid, butyric acid, hexanoic acid, and the like. Both the cracking catalyst and the trimerization catalyst are present throughout the conversion of the silylorganocarbamate to silylisocyanurate in the process of U.S. Pat. No. 5,218,133. Due to toxicity and/or environmental considerations, the foregoing aluminum-containing and tin-containing cracking catalysts, if solid, must be separated from the liquid product stream or, if liquid, will remain dissolved in the product stream where they can cause instabilities such as an increase in color and/or adversely affect the end use(s) of the product silylisocyanurate.
[0006] The utilization of aluminum-containing and tin-containing cracking catalysts for the production of silylisocyanurate therefore involves certain disadvantages, either for the cracking/trimerization process itself or, potentially, for the silylisocyanurate product resulting from the process.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, a process for making silylisocyanurate is provided which comprises cracking silylorganocarbamate in the presence of a catalytically effective amount of, as cracking catalyst, at least one caboxylate salt selected from the group consisting of ammonium carboxylate, alkali metal carboxylate and alkaline earth metal carboxylate to provide silylorganoisocyanate and trimerizing silylorganoisocyanate in the presence of the caboxylate salt to provide silylisocyanurate.
[0008] The foregoing process dispenses entirely with the metal-containing alkoxide and tin-containing cracking catalysts of U.S. Pat. No. 5,218,133 which may actually hinder the progress of the subsequent trimerization reaction which provides the desired silylisocyanurate product. The metal-containing alkoxides and tin-containing compounds of U.S. Pat. No. 5,218,133 will therefore ordinarily be substantially absent from the reaction medium of the process of this invention. By omitting either of these known types of cracking catalyst, the process of this invention provides a clean, rapid and relatively simple trimerization procedure. Although filtration of the carboxylate salt catalyst herein is required, this substance is non-toxic and presents no particular environmental hazard or waste disposal problem.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The process of this invention results in the production of silylisocyanurate. In one embodiment of the process, isocyanurate preparation can be represented by the general reaction scheme
wherein each R independently is a divalent hydrocarbon group having 2 to 11 carbon atoms and preferably 3 to 5 carbon atoms; each R 1 independently is an alkyl or halogenated alkyl group having 1 to 8 carbon atoms, an aryl group having at least 6 ring carbon atoms, or an aralkyl group; each X independently is a hydrolyzable alkoxy group, trialkylsiloxy group or alkoxy-substituted alkoxy group; and, a is an integer from 0 to 3 inclusive; and, each R 2 is an alkyl group having 1 to 8 carbon atoms.
[0010] The silylorganocarbamate from which the foregoing silylisocyanurate is obtained can be prepared in accordance with any known or conventional process, e.g., the process of U.S. Pat. No. 5,218,133, the entire contents of which are incorporated by reference herein. In brief, the silylorganocarbamate can be prepared by reacting an aminosilane, e.g., an aminoalkyltriethoxysilane such as aminopropyltrimethoxysilane, aminopropyltriethoxysilane, etc., with a dialkylcarbonate, diarylcarbonate or mixture thereof such as dimethylcarbonate, diethylcarbonate, dipropylcarbonate, dibutyl carbonate, diphenylcarbonate, etc., in the presence of a basic catalyst, e.g., an alkali metal alkoxide such as sodium methoxide (sodium methylate) which, following the reaction to produce the silylorganocarbamate, is neutralized with a carboxylic acid such as formic acid, glacial acetic acid, propanoic acid, butanoic acid, etc. to form the corresponding alkali metal carboxylate, i.e., a carboxylate salt which is useful as a catalyst for the cracking reaction of the process of this invention.
[0011] It is advantageous to employ a silylorganocarbamate in the process of this invention which is made with an alkali metal alkoxide subsequently neutralized with carboxylic acid since the catalyst for the process will then already be present in the silylorganocarbamate reactant. Accordingly, it is a particular aspect of this invention to prepare a silylorganocarbamate in this way for utilization in the cracking/trimerization process herein. Preparing the silylorganocarbamate reactant in the aforesaid manner obviates the need to remove alkali metal carboxylate salt therefrom which is indicated to be preferred in U.S. Pat. No. 5,218,133.
[0012] Examples of silylorganocarbamate reactant which are useful in the practice of the process of this invention include methyl N-3-(trimethoxysilyl)-propylcarbamate, ethyl N-3-(trimethoxysilyl)propylcarbamate, methyl N-3-(triethoxysilyl)propylcarbamate, methyl N-3-(methyldimethoxysilyl)propylcarbamate, methyl N-3-(dimethylmethoxysilyl)propylcarbamate, methyl N-3-(triethoxysilyl) propylcarbamate, ethyl N-3-(triethoxysilyl)propylcarbamate, methyl N-3-(methoxydiethoxysilyl)propylcarbamate, methyl N-3-(trimethoxysilyl)butylcarbamate, methyl N-3-(triethoxysilyl)butylcarbamate, and the like.
[0013] The carboxylate salt cracking catalyst employed in the process of the invention is at least one ammonium carboxylate, alkali metal carboxylate or alkaline earth metal carboxylate.
[0014] The term “ammonium” shall be understood herein to include the ammonium cation, NH 4 + , and the mono-, di-, tri- and tetrahydrocarbyl-substituted variants thereof.
[0015] The term “carboxylate” shall be understood herein to mean the salt of a monocarboxylic acid, dicarboxylic acid or dicarboxylic acid anhydride of up to about 20 carbon atoms and advantageously of up to about 12 carbon atoms.
[0016] Illustrative of the ammonium carboxylate salt cracking catalysts herein are ammonium formate, ammonium acetate, ammonium propanoate, ammonium n-butanoate, ammonium n-pentanoate, ammonium 2-methylpropanoate, ammonium 3-methylbutanoate (valerate), ammonium benzoate, tetramethylammonium acetate, tetraethylammonium acetate, tetrabutylammonium acetate, tetramethylammonium 2-ethylhexanoate, tetraethylammonium 2-ethylhexanoate, tetramethylammonium benzoate, tetraethylammonium benzoate, tetrapropylammonium benzoate, tetrabutylammonium benzoate, and the like.
[0017] Illustrative of the alkali metal carboxylates are lithium formate, lithium acetate, lithium propanoate, sodium formate, sodium acetate, sodium propanoate, sodium n-butanoate, sodium n-hexanoate, sodium oleate, sodium laurate, sodium palmitate, disodium malonate, disodium succinate, disodium adipate, and the like.
[0018] Illustrative of the alkaline earth metal carboxylate cracking catalysts herein are the calcium, magnesium and barium carboxylates derived from formic acid, acetic acid, propanoic acid, n-butanoic acid, and the like.
[0019] The alkali metal carboxylates are readily available or are easily manufactured, e.g., in situ, and generally provide good results. Alkali metal formates are especially advantageous for use herein in that they appear to be more readily removed by filtration from the reaction product mixture than, say, the corresponding acetates and carboxylates of higher carboxylic acids. The alkali metal carboxylate salt is advantageously already present in the silylorganocarbamate reactant due to the manufacturing procedure described above in which the alkali metal alkoxide catalyst used in making the silylorganocarbamate is neutralized post-reaction with carboxylic acid. Alternatively, the alkali metal carboxylate can be generated in situ by the addition of alkali metal alkoxide and carboxylic acid to the silylorganocarbamate and/or previously prepared alkali metal carboxylate can be added to the silylorganocarbamate.
[0020] Regardless of how the carboxylate salt catalyst is introduced into the reaction medium, it must be present in a catalytically effective amount for the cracking reaction and must continue to be present for the subsequent trimerization reaction to provide product silylisocyanurate. In general, from about 0.01 to about 0.5 weight percent, and advantageously from about 0.05 to about 0.2 weight percent, of carboxylate salt catalyst based upon the total amount of silylorganocarbamate in the reaction medium can be utilized with generally good results.
[0021] The process of the invention can be carried out by heating the silylorganocarbamate-containing reaction mixture in the presence of the carboxylate salt cracking catalyst under subatmospheric pressure for a sufficient period of time for substantially complete overall conversion of the silylorganocarbamate to silylisocyanurate to take place. Those skilled in the art can readily optimize these process conditions for a particular silylorganocarbamate reactant and carboxylate salt cracking catalyst employing straightforward experimental procedures. Reaction times ranging from about 10 minutes to about 24 hours, advantageously from about 15 minutes to about 1 hour, temperatures ranging from about 160° C. to about 250° C., advantageously from about 190° C. to about 210° C., and pressures ranging from about 5 to about 400 millimeters Hg (about 0.65 kPa to about 26 kPa), advantageously from about 75 to about 300 millimeters Hg (from about 2 kPa to about 9.8 kPa), generally provide good results.
[0022] Among the silylisocyanurates that can be readily and conveniently prepared by the process of this invention are 1,3,5-tris[3-(trimethoxysilyl)propyl]-isocyanurate; 1,3,5-tris[3-(triethoxysilyl)propyl]isocyanurate; 1,3,5-tris[3-(methyldimethoxysilyl)propyl]isocyanurate; and, 1,3,5-tris[3-(methyldiethoxysilyl)propyl]-isocyanurate.
[0023] In the examples that follow, silylorganocarbamate is prepared by the process of U.S. Pat. No. 5,218,133 employing sodium methoxide catalyst and neutralizing the catalyst following completion of the reaction with organic acid, specifically, formic acid and acetic acid, the latter as disclosed in U.S. Pat. No. 5,218,133. Neutralization is carried out to a pH of about 9-4, by-product alcohol is stripped by heating to 210° C. while slowly decreasing pressure so that the column remains relatively cool. The evolved alkanol, in this case methanol, is removed to a receiver. When the pressure reaches a desired value without noticeable methanol removal, the reaction is determined to be substantially complete. This change in pressure profile is an important function of the process. If the pressure is immediately reduced to less than 100 mmHg, the temperature cannot quickly reach 200° C. due to heavy reflux of both the silylcarbamate and silylisocyanate thus resulting in undesirably extended reaction times.
EXAMPLE 1
[0024] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, Vigreaux column, thermocouple and distillation head was added 900 g of previously prepared crude methyl N-3-(trimethoxysilyl)propylcarbamate containing sodium methoxide catalyst used in its production, unreacted dimethylcarbonate and methanol by-product. The reaction medium was neutralized with 1.97 grams of formic acid and briefly agitated resulting in the formation of sodium formate in situ. The solvent pH was measured at 5.9. The mixture was then heated to 130° C. under atmospheric pressure to remove dimethylcarbonate and methanol. The stirred reaction mixture containing the sodium formate formed in situ was then rapidly heated to 210° C. with initial pressure set at 365 mmHg. When the temperature reached 185° C., a sample was removed for measurement of pH, which was 5.6. For comparative purposes, the time when the temperature reached 185° C. was set as T=0. At this time, there was no evidence of reaction as evidenced by vapor evolution. After T=3 minutes, there was evidence of methanol vapors and the temperature had slightly exceeded the setpoint and reached 214° C. Another sample for pH showed an increase to 8.3. At T=18 minutes, the vapors evolution was heavy and the pH had reached 10.0. The pressure was reduced to 87 mmHg in stages until no more takeoff of lights was observed. At this time the reaction was determined to be substantially complete. Total time was 30 minutes. The reaction mixture was cooled to room temperature and the mixture was easily pressure-filtered through a 12 micron pad.
[0025] The reaction was monitored via gas chromatography (GC) with comparison to known peaks. As samples were removed for pH measurement, they were also analyzed by GC. The conversion was measured by disappearance of the combined carbamate/isocyanate peak. At maximum conversion, the major peak by GC was determined to be 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate. Table 1 sets forth the conversion with respect to time.
TABLE 1 Conversion with Respect to Time Reaction Time (min) Conversion (wt. %) 0 0 3 12.2 18 73.9 30 94.4
EXAMPLE 2
[0026] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, Vigreux column, thermocouple, and distillation head was added 900 g of previously prepared crude methyl N-3-(trimethoxysilyl)propylcarbamate containing sodium methoxide catalyst used in its production. This mixture was neutralized with approximately 6 grams of acetic acid and briefly agitated resulting in the formation of sodium acetate in situ. The solvent pH was measured at 6.2. This mixture was then heated to 130° C. under atmospheric pressure to remove the dimethylcarbonate and methanol. The stirred reaction mixture containing the sodium acetate formed in situ was then rapidly heated to 210° C. with initial pressure set at 383 mmHg. At a temperature of 187° C., the pH of the sample was 6.1. No reaction was observed at this time. For comparison purposes, this was set at T=0. After 20 minutes, temperature had reached 206° C. with very little evidence of reaction. The pH of the mixture was 6.4. After 55 min, gas evolution was observed. The conditions were 207° C. and 250 mmHg and the reaction pH was 8.6. After a total of 1 hr and 15 min the reaction was terminated and the reaction medium cooled to room temperature. The mixture was pressure filtered through a 12 micron pad. The filtration was noticeably more difficult than that of Example 1.
[0027] The reaction was monitored via gas chromatography with comparison to known peaks. As samples were removed for pH measurement, they were also analyzed by GC. The conversion was measured by disappearance of the combined carbamate/isocyanate peak. At maximum conversion, the major peak by GC was determined to be 1,3,5-tris[3-(trimethoxysilyl) propyl] isocyanurate. Table 2 sets forth the conversion with respect to time.
TABLE 2 Conversion with Respect to Time Reaction Time (min) Conversion (wt. %) 0 0 20 9.0 55 73.1 75 83.2
[0028] Comparing these data with that of Table 1 of Example 1, it will be seen that there is a significant increase in conversion with respect to time with sodium formate as cracking catalyst compared to sodium acetate cracking catalyst.
EXAMPLE 3
[0029] To a 110 gallon reactor were added 500 lbs of crude methyl N-3-(trimethoxysilyl)propylcarbamate containing sodium methoxide catalyst used in its production and 550 grams of formic acid to produce sodium formate in situ. The mixture containing the sodium formate formed in situ was briefly agitated and the resulting solvent pH was found to be 5.7. After the mixture was stripped of lights at a temperature of 135° C. and atmospheric pressure, the reactor temperature was brought to 210° C. with the initial vacuum at 350 mmHg. The temperature was held at 210° C. while the pressure was reduced at such a rate to keep the differential pressure of the column less than 10 mmHg. After heating for 1.75 hrs, the final pressure was 70 mmHg. With a negligible difference in pressure across the column, the reaction was considered to have been substantially complete. The reaction mixture was cooled to room temperature, and a portion of the mixture was readily pressure filtered through a 5 micron pad using Celite 535 as a filter aid. NMR analysis and gas chromatography verified the product as 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate meeting all specifications typical of commercial material.
EXAMPLE 4
[0030] Dimethylcarbonate (282 lbs) and 25% sodium methoxide (8 lbs) were charged to a 110 gallon reactor. 3-Aminopropyltrimethoxysilane was added to this mixture from an auxiliary tank at 200-250 lbs/hr. The reaction was allowed to exotherm to 50° C. where it was held for 2 hrs after addition was complete. The carbamate reaction was determined to have been substantially complete by titration. To the reaction mixture was added 2.5 kg formic acid to produce sodium formate in situ. The mixture containing the sodium formate formed in situ was briefly agitated and then the lights were stripped at 135° C. and atmospheric pressure. After stripping, the reactor temperature was increased to 210° C. with initial pressure of 359 mmHg. As reaction proceeded, the pressure was reduced such that the differential pressure of the column was less than 10 mmHg. After heating for 2 hrs and 10 minutes, the reaction was determined to have been substantially complete when the pressure reached 94 mmHg with negligible differential pressure across the column. The reaction mixture was cooled to room temperature with a portion of the mixture being readily pressure filtered through a 5 micron pad using Celite 535 as a filter aid. NMR analysis and gas chromatography confirmed that the product was 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate meeting all specifications typical of a commercial material.
EXAMPLE 5
[0031] To a 110 gallon reactor were added 500 lbs of crude methyl N-3-(trimethoxysilyl)propylcarbamate containing sodium methoxide catalyst used in its production and 1,066 grams of acetic acid to produce sodium acetate in situ. The mixture was briefly agitated and the resulting solvent pH was found to be 6.5. After the mixture was stripped of lights at a temperature of 135° C. and atmospheric pressure, the reactor temperature was brought to 210° C. with the initial vacuum at 248 mmHg. The temperature was held at 210° C. while the pressure was reduced at such a rate to keep the differential pressure of the column less than 10 mmHg. After heating for 3.5 hrs, the final pressure was 66 mmHg. With negligible differential pressure across the column, the reaction was determined to have been substantially complete. The reaction mixture was cooled to room temperature with a portion of the mixture being pressure filtered through a 12 micron pad using Celite 535 as a filter aid only with considerable difficulty. NMR analysis and gas chromatography confirmed that the product was 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate meeting all specifications typical of a commercial material.
EXAMPLE 6
[0032] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, Vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. This mixture was treated with 7.0 grams of 25% sodium methoxide solution and 1.5 grams of formic acid to produce sodium formate in situ. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held around 200° C. for 2 hrs. The pressure was gradually reduced to 70 mmHg during this time. The mixture was then cooled and filtered.
[0000] The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak, was found to be 94%. The 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate was approximately 73% of the final mixture.
EXAMPLE 7
[0033] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, Vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. This mixture was treated with 7.0 grams of 25% sodium methoxide solution and 1.9 grams of acetic acid to produce sodium acetate in situ. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held around 200° C. for 2 hrs. The pressure was gradually reduced to 70 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak, was found to be 89%. The 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate was approximately 81 wt. % of the final mixture.
EXAMPLE 8
[0034] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. To this material was added 2.49 grams of sodium acetate trihydrate. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held between 200-210° C. for 2 hrs. The pressure was gradually reduced to 75 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak as measured by gas chromatography, was found to be 95% The 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate was approximately 72 wt. % of the final mixture.
EXAMPLE 9
[0035] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. To this material was added 1.55 grams of potassium acetate. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held around 200° C. for approximately 1 hr. The pressure was gradually reduced to 75 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak as measured by gas chromatography, was found to be 96%. The 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate was approximately 54 wt. % of the final mixture.
COMPARATIVE EXAMPLE 1
[0036] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. No carboxylic acid or alkali metal carboxylate was added to this material. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held between 200-210° C. for 6 hrs. The pressure was gradually reduced to 105 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak as measured by gas chromatography, was found to be 30%. 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate constituted only about 1 wt. % of the final mixture.
COMPARATIVE EXAMPLE 2
[0037] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. This mixture was treated with 1.96 grams of acetic acid and briefly agitated. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held between 200-210° C. for 6 hrs. The pressure was gradually reduced to 98 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate constituted only about peak, was found to be 24%. 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate constituted only about 1 wt. % of the final mixture.
COMPARATIVE EXAMPLE 3
[0038] To a 2 L 4 necked round bottom flask equipped with overhead stirrer, vigreux column, thermocouple, and distillation head was added 750 grams of methyl N-3-(trimethoxysilyl)propylcarbamate that was previously distilled to remove any alkali metal carboxylate. To this material was added 1.13 grams of aluminum ethoxide. The stirred reaction mixture was then rapidly heated to 200° C. with initial pressure set at 300 mmHg. The temperature was held between 200-210° C. for 6 hrs. The pressure was gradually reduced to 120 mmHg during this time. The mixture was then cooled and filtered. The conversion, which was measured by disappearance of the combined carbamate/isocyanate peak as measured by gas chromatography, was found to be 39% 1,3,5-tris[3-(trimethoxysilyl) propyl]isocyanurate constituted only 0.8% of the final blend.
Reaction % Wt. % Silyl- Example Additive(s) Time (hrs) Conversion isoyanurate 6 NaOMe/Formic 2 94 73 acid (forming HCOONa in situ) 7 NaOMe/Acetic 2 89 81 acid (forming CH 3 COONa in situ) 8 NaOAc 2 95 72 9 KOAc 1 96 54 Comp 1 None 6 30 1.0 Comp 2 Acetic acid 6 24 1.0 Comp 3 Al(OEt) 3 6 39 0.8
[0039] While the process of the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the process of the invention but that the invention will include all embodiments falling within the scope of the appended claims. | A process for making silylisocyanurate reacts silylorganocarbamate in the presence of at least one carboxylate salt selected from the group consisting of ammonium carboxylate, alkali metal carboxylate and alkaline earth metal carboxylate as cracking catalyst to provide silylorganoisocyanate which then undergoes trimerization in the presence of the carboxylate salt to silylorganocyanurate. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/544,064, filed on Oct. 6, 2011, entitled METHOD OF REDUCING DOWNWARD FLOW OF AIR CURRENTS ON THE LEE SIDE OF EXTERIOR STRUCTURES, the entire disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
As shown in FIGS. 1-2 , emissions emitting building structures 2 , typically industrial factories or utility generating structures, often utilize an emission tower or towers, such as a steam tower (steam emitting cooling tower), cooling tower, or smokestack. The emission tower is typically located on a roof 6 or other elevated surface of the emissions emitting structure. When directional winds/air currents 8 flow past an exterior structure, such as an emission emitting structure (steam) tower containing facility, toward neighboring properties including roads 10 , the base structure itself can cause or contribute to emissions such as generated steam or smoke to be drawn downward on the leeward side 12 of the structure 2 . As a consequence, rather than being carried up into the atmosphere, these emissions 14 may then flow at very low altitudes across and/or along the contours of the land for some distance on the leeward side 12 of the building structure 2 . This reduces visibility on such neighboring properties and/or causes other undesired negative effects. Some undesired effects include causing dangerously unsafe driving conditions by reducing visibilities along affected stretches of roadways (see FIG. 1 , for example). This effect is more problematic when the road proximate the emission emitting structures is at an altitude higher than the altitude of the base of the emissions emitting structure as shown in FIG. 1 .
SUMMARY OF THE INVENTION
An embodiment of the present disclosure is directed to a method of reducing the downward flow of air currents on the leeward side of an emissions emitting structure comprising the step of using a system that includes components chosen from the group consisting of one or more mechanical air moving devices; physical structures; and combinations thereof to create an increase in the air pressure within a volume of air on the leeward side of an emissions emitting structure having emissions that become airborne. The increased air pressure prevents or lessens downward flow of emissions that would occur without the use of the system.
Yet another aspect of the present disclosure is directed to a method of reducing the downward flow of air currents on the leeward side of an emissions emitting structure comprising the steps of (1) installing components outside and proximate the emissions emitting structure wherein the components are chosen from the group consisting of one or more industrial fans; one or more vertically or substantially vertically oriented walls that are at least 20% of the height of a tallest exterior wall on the leeward side of the emissions emitting structure; and (2) creating an increase in the air pressure within a volume of air proximate and along the leeward side of an emissions emitting structure using the components to cause at least two airflows to meet one another and create the increase in the air pressure that reduces the downward flow of air currents on the leeward side of the emissions emitting structure.
Another aspect of the present disclosure is generally directed to a method of reducing the downward flow of air currents on the leeward side of an emissions generating building and preventing emissions from lessening or blocking the visibility of a motorist traveling a road near the building comprising the step of: creating an increased air pressure zone proximate the leeward side of the building by using at least one airflow creating system that includes components chosen from the group consisting of two or more mechanical air moving devices; physical airflow directing structures; and combinations thereof to create at least two airflows that meet proximate, more typically along, the leeward side of the emission generating building and increase the air pressure within the zone of air on the leeward side of an emissions generating building chosen from the group consisting of a factory having emissions that become airborne, a power plant having emissions that become airborne, and an industrial or commercial facility having emissions that become airborne; wherein the increased air pressure zone prevents or lessens downward flow of emissions that would occur without the use of the system and presents the emissions from lessening or blocking the visibility of the motorist traveling the road.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side schematic view showing the current problems and general conditions around an emissions (steam) tower containing facility near a roadway;
FIG. 2 is a top schematic view showing the current problems and general conditions around an emissions (steam) tower containing facility near a roadway;
FIG. 3 is a side schematic view of an aspect of the present emissions elevating method/apparatus/system;
FIG. 4 is a top schematic view of an aspect of the present emissions elevating method/apparatus/system; and
FIG. 5 is a top schematic view of another embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention. However, it is to be understood that the invention may assume various alternative orientations, 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 and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.
The present disclosure is directed to both a system that is installed around an emissions emitting structure 2 , such as a factory or utility generating structure, as well as a method that uses the system to prevent emissions 14 from being drawn downward to ground level altitudes (on the leeward side 12 of the emissions emitting structure), but instead assist in raising the emissions, typically into higher altitudes of the atmosphere, thereby reducing or eliminating negative effects on neighboring properties and roadways. This is typically done by creating a volume of air or a zone 16 of increased air pressure where at least two airflows 18 , 20 intersect. While a single airflow pair will function to create the increased air pressure volume proximate the leeward side of the emissions emitting structure, a plurality of airflow streams from one or more natural (such as redirected naturally occurring airflow, typically wind) or manmade systems (such as one or more mechanical air moving devices, typically industrial strength fans) may be used to create the increased air pressure volume or zone 16 . The increased air pressure volume or zone may be anywhere along and typically proximate the leeward side 12 of the emissions emitting structure(s), more typically within about ½ mile or less of the leeward side 12 .
As air currents 8 meet a windward side 24 of the obstacle, typically an emissions emitting structure, an air pressure greater than ambient is created on the windward side 24 of the structure by the compression of the wind against the structure, while on the leeward side 12 of the structure an air eddy of swirling winds is formed in which the air pressure is less than ambient. This lower air pressure on the leeward side of the structure then acts to draw emissions from above the structure down toward itself, after which the emissions are picked up by low altitude winds and carried across neighboring property and roadways. The present system and method remediates this underlying condition thereby preventing any deleterious effects to roadways, property, and people.
According to an embodiment of the present invention, the method and/or system remediates the undesired condition of emissions being drawn downward on the leeward side of a structure by purposely increasing the air pressure on the structure's leeward side 12 to an amount that equals or exceeds that air pressure which exists immediately above the structure. This can be accomplished by a variety of way or combination of ways described herein.
As shown in FIGS. 3-5 , the increase in air pressure can be achieved by using a system that includes components chosen from one or more of the following: one or more air moving devices; physical structures; and combinations thereof. In one preferred embodiment, the method uses a combination of one or multiple industrial sized fans or other air generating and/or moving devices 22 such as a turbine engine, or other air moving devices near ground level, the exhausts of which shall be directed and/or guided by piping 26 and/or diversion panels 28 in such a manner as to add to the volume and pressure of air on the leeward side 12 of the structure(s) 2 . The devices shall be of such volumetric capability as to increase the air pressure on the leeward side of the structure to an amount equal to, or greater than, the air pressure immediately above the structure. A plurality of fans is typically used and is typically positioned at an angle to an exterior leeward wall surface of the emissions emitting structure. The fans are typically positioned at an angle up to 80 degrees from the exterior leeward wall surface of the emissions emitting structure. Emissions are thereby caused to remain at the altitude at which they are emitted, or rise to higher levels, at which they are not considered to be undesirable.
While shown in the attached FIGS. 3-4 as airflow directed at one another, applicant presently believes that the fans may function better if positioned such that the airflow streams from at least two opposing fan generated airflow streams strike one another at an angle to the surface of the emission towers, typically an angle of up to about 80 degrees, more typically from 10-75 degrees, most typically at an angle of between 40-50 degrees from the surface of the leeward side of the emissions emitting structure(s). While facing the airstreams toward one another as in FIGS. 3-4 achieves some benefit, it is believed that positioning the airflow at an angle to one another provides superior and unexpectedly better emissions (steam) removal according to the present invention. Also, if the wind is at an angle to the windward side of the emissions emitting structure, activation of a single fan or airflow generating device or wall may be used to generate the necessary increase in air pressure proximate the leeward surface of the structure.
As shown in FIGS. 3-4 , the diversion panels 28 , which are typically walls that are ideally braced and/or partially buried underground for added strength, are typically positioned parallel or substantially parallel to the leeward wall of the emissions emitting structure 2 when mechanical air moving devices are used. In addition to the system shown in FIGS. 3-4 , diversion walls may be used with or without the air moving devices and vice versa. Typically, if diversion panels or walls are used they are at least about 20% of the height of the tallest exterior wall on the leeward side of the emissions emitting structure, at least about 50% of the height of the tallest exterior wall on the leeward side of the emissions emitting building, but typically 100% or less of the height of the tallest exterior wall on the leeward side of the emissions emitting structure. The panels or walls 28 may be positioned at an angle (see FIG. 5 ) to the leeward side of the emission emitting structure. When at an angle, at least one pair of panels or walls 28 are typically employed and positioned and configured to redirect wind received from the windward direction into at least two separate airflows that are directed toward one another along the leeward side of the emission emitting structure to form the increased air pressure that prevents or lessens downward flow of emissions. The walls may each include a first portion 30 and a second portion 32 that are at an obtuse angle to one another and ideally curved at their juncture to form a smooth airflow path to maximize the redirection of wind. The first portion is typically longer than the second portion to capture and redirect a greater amount of wind airflow from the windward direction that does not encounter or goes around the sides of the structure.
The lessening of the downward flow of the emissions that would occur without the use of the system prevents the emissions from lessening or blocking the visibility of motorists or other travelers on roads proximate the emissions emitting structure 2 . Typically roads as far away as about ½ mile (distance A in the Figures) from the emissions generating building see benefits from the present invention, but more typically the road is about ¼ mile or less and even more typically about 400 feet or less from the leeward side of the emissions emitting structure(s). A plurality of systems or portions of the systems for redirecting or creating airflow streams may be used in the context of the present invention. | A method of reducing the downward flow of air currents on the leeward side of an emissions emitting structure including the step of using a system that includes components chosen from the group consisting of one or more mechanical air moving devices; physical structures; and combinations thereof to create an increase in the air pressure within a volume of air on the leeward side of an emissions emitting structure having emissions that become airborne. The increased air pressure prevents or lessens downward flow of emissions that would occur without the use of the system and increases the safety by which one can travel a road or other transportation route that might otherwise be visually obscured by the emissions and the safety of the property and those within the area where emissions occur. | 8 |
BACKGROUND TO THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an automated milking stall for animals such as cattle, goats and the like.
[0003] 2. Description of Related Art
[0004] Such milking stalls or parlours are known per se and comprise an entry gate via which the animal will enter the parlour and which is closed during milking to retain the animal in the parlour; an exit gate which opens automatically when milking has ended and a robot arm which carries, at its distal end, teat cups. The robot arm is automatically movable into (and, when milking is finished, out of) a position in which the teat cups may engage with the teats of the animal.
[0005] Automated milking parlours are also known to comprise or be linked to various analysis equipment whose purpose is to record and analyse parameters associated with both the milking process and the milk yielded by that process. The purposes of such analyses include the obtaining of data on the individual animal's milk yield as well as to establish whether the animal is, at the time of milking, displaying indications of illness requiring intervention and/or withhold of its milk from human consumption. The process of automation in animal milking is known to use data obtained during milking which indicates illness then to segregate the unwell animal. Typically, this will involve herding the animal, once it has exited the milking parlour, into a separate compound using an automated gate. Alternatively, the animal may be segregated for routine attention on the instruction of the operator.
SUMMARY OF THE INVENTION
[0006] The present invention provides a milking stall comprising a base structure to which an enclosing frame is mounted; the enclosing frame including at least one entrance gate and first and second exit gates each of the gates being movable between an open position in which an animal may pass though the gate and a closed position in which an animal is unable to do so. In a preferred embodiment, the stall comprises a control system which is operable to actuate the first exit gate when a signal is received indicating that the animal is unwell or otherwise required for individual attention and to actuate the second exit gate when a signal is received indicating there is no requirement to segregate.
BRIEF DESCRIPTION OF DRAWINGS
[0007] Embodiments of the invention will now be described, by way of example, and with reference to the accompanying drawings, in which:
[0008] FIG. 1 is a perspective view of an embodiment of milking stall according to the present invention;
[0009] FIG. 2 is a plan view of the embodiment of FIG. 1 ;
[0010] FIG. 3 is a plan view of a detail of FIGS. 1 and 2 ;
[0011] FIGS. 4 to 7 are plan views of different modes of operation of the embodiment of milking stall according to the present invention; and
[0012] FIG. 8 is a schematic illustration of control of the exits to the embodiment of milking stall in FIGS. 1 to 7 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Referring now to FIGS. 1 to 3 , an automated milking stall for comprises a planar base 10 and, mounted upon the base, a pen 12 . In the present embodiment the stall is designed for milking cattle, though this is not essential. The pen 12 is rectangular in plan view and comprises a wall 14 which forms one of the longer sides of the enclosure. The wall 14 extends from the upper level of the enclosure to about halfway down, thereby leaving a substantial gap at the bottom. The gap enables a robotically-controlled arm 40 to swing under the wall 14 and engage with a cow's udder for automated milking as will be described subsequently.
[0014] The remaining sides of the pen 12 are provided by a series of gate sections 16 A, B, C D (shown most readily in FIG. 3 ). Each gate section 16 is mounted to a rectangular frame 15 A,B,C situated at the ends and the middle of the pen 12 . Each gate section 16 comprises a substantially rectangular frame 18 made of tubular spars, typically of galvanised steel though any suitable material may be used. A series transverse struts 20 , also made of tubular galvanised steel extend across each frame 18 , with the lowermost strut 18 of each gate section 16 and the adjacent parts of the frame 18 each supporting a panel 22 . The panels 22 extend transversely around the lowermost part of the three sides of the pen 12 enclosed by the gate sections 16 and serve to avoid or minimise damage to an animal's lower leg in the event that it starts to kick while in the enclosure.
[0015] The size of the pen is chosen so that, when an animal is enclosed within the pen 12 its movement is significantly restricted and, as a consequence of which, its udder will be known to be located within a very small area. Once enclosed, this enables a robotic arm, mounted to the remote side of the wall 14 ( FIG. 1 ) to articulate under the wall 14 and to engage with the teats of the cow's udder. Once engaged, milk is extracted from the teats via milk cups (not shown) on the robotic arm into a milk receptacle (not shown) and mounted to the far side of the wall 14 . Typically, milk either within the receptacle or which is being transmitted to it will be analysed physically and/or chemically for one or more ‘marker’ measurements which indicate animal illness. In the event that illness is indicated, it will be desirable to segregate the animal from the remainder of the herd both to prevent any possible spread of illness and to ensure the animal may receive appropriate treatment.
[0016] Referring now additionally to FIGS. 4 and 5 , in a preferred embodiment two entry gates, 16 A, B are pivotally mounted to a end frame 15 A for a hinged motion relative to the base 10 thereby providing two alternative entry locations into the milking stall. Thus, gate section 16 A is pivotally mounted to a vertical strut 22 forming part of frame 15 A in a manner permitting hinged opening of the gate section 16 A to allow a cow ‘straight entry’ into the stall, as shown in FIG. 4 . Similarly, gate section 16 B is pivotally mounted to the centre frame 15 B for hinged opening which therefore permits entry into the stall of cattle from a different direction. The stall likewise comprises two exit gates. Thus, gate section 16 C is pivotally mounted for hinged opening from middle frame 15 B, while gate section 16 D is pivotally mounted for hinged opening from end frame 15 C. Thus, by means of two differing entry gates, it is possible to select cattle for milking from one of two different animal compounds, for example, and to direct them to one of two different exit compounds. Thus, FIG. 4 illustrates entry via gate 16 A which may open onto a first compound; while FIG. 5 , illustrating entry via gate 16 B, may open onto a second, distinct compound.
[0017] Referring additionally to FIGS. 6 and 7 , equally, exit may be via gate 16 C as illustrated in FIG. 6 ; or via gate 16 D as illustrated in FIG. 7 . If, therefore, it transpires that a cow is diagnosed from the analysis of its milk as showing indications of illness and/or is required for routine operator attention, it can be forced to exit the stall by (say) the gate 16 C which opens onto a compound that is entirely separate to the compound onto which ordinary exit gate 16 D opens and therefore provides instant and complete segregation of the animal from the moment at which the first indication of the animal's potentially poor health has been detected. Notably, and as illustrated in FIGS. 3 to 7 , a feed container 30 is preferably located on an exit gate 16 D (though the container may equally be located elsewhere in a location accessible by the animal when located inside the pen)
[0018] Referring now to FIG. 8 , control of the gates may, in one preferred embodiment, be based upon the health of the animal. Thus, according to one embodiment, an infra red camera 100 is located on a frame 15 A, B, C and scans the animal whilst it is milking. An IR scan analyser 110 establishes whether the temperature of the animal is within a range which would indicate normal health, or whether the animal's temperature indicates ill-health. The output signal of the scan analyser 110 is sent to the control system 120 . If the scan analyser output signals normal health, the control system operates the hydraulic actuator 60 associated with gate 16 D and the animal exits the pen of the stall to join the other animals. If, however, the scan analyser output signals ill health, the control system operates the motor on gate 16 C and the animal exits to an entirely separate compound without ever, at any subsequent point, coming into contact with any of the other animals. For ease of illustration only a single sensor, here an IR sensor to indicate body temperature, has been shown. It is equally possible to employ a plurality of such sensors; further it is possible to employ sensors of other parameters which indicate animal wellbeing, such as animal contours for body condition scoring and the like. Further, where ill health is to be used as a basis upon which to control the gate operation, it is not essential to use IR-generated animal heat data; alternative data may be used, such as analysis of the milk temperature and/or composition, for example.
[0019] Further, the control system may equally operate upon bases other than animal health. Thus, the control system could be pre-programmed with the identities of specific animals which it is desire to segregate for other reasons and, when he RFID of the or each such animal is detected when milking and transmitted to the control system, the control system may operate to divert the animal out of the appropriate exit gate.
[0020] In this way the milking stall can be used additionally as an instant filtering mechanism for animal traffic. | A milking stall includes a base structure supporting a pen within which an animal undergoing milking may be enclosed, the pen including at least one entrance gate and first and second exit gates, each gate being movable between an open position in which an animal may pass through the gate and a closed position in which an animal is unable to do so. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to coating compositions and coated articles and to processes for preparing the same.
While certain substrates are inherently receptive to certain later-applied materials, many are not. For instance, many substrates, such as those made of polyester and other plastics, cellulose acetate, spunbonded olefin and metal are not receptive to the aqueous inks used in ink jet, xerographic, air brush, hand marking or other printing methods. Such substrates are not readily wetted and tend to repel water-based ink solutions, causing the ink droplets to coalesce into larger drops or puddles. This limits the amount of ink that can be deposited on the substrate and has negative effects on the appearance and resolution of the printed substrates. Furthermore, there exists a problem of retention of the aqueous ink on the substrate, which can result in smudging as well as the printing flaking off or being actually washed away upon contact with water.
Accordingly, it is a principal object of this invention to provide a coating for a substrate, which coating is receptive to certain later-applied materials.
It is another object of the invention to provide such a coating which is receptive to aqueous ink.
It is a further object of the invention to provide such a coating which is capable of retaining the aqueous ink.
It is a still further object of the invention to provide such a coating which is smudgeproof and which will not wash off with water.
SUMMARY OF THE INVENTION
The problems of the prior art are overcome by the provision of a coating having receptivity for later-applied materials, e.g., a printable coating, for application to various substrates.
A coated article of the invention may be prepared by a process comprising the steps of:
(a) providing a substrate;
(b) coating at least one surface of said substrate with a coating composition formed by:
(1) mixing an olefin copolymer containing pendant acid groups with a base capable of substantially neutralizing said acid groups and an aqueous liquid to form an aqueous solution; and
(2) mixing the aqueous solution of (1) with an aqueous solution of a 2-oxazoline polymer; and
(c) drying said coating.
Preferably, the olefin copolymer comprises polyethylene acrylic acid copolymer and the 2-oxazoline polymer comprises polyethyloxazoline. In one embodiment of the invention, the coating composition is formed by mixing the aqueous solution of the olefin copolymer having pendant acid groups, which pendant acid groups have been substantially neutralized by the base capable of neutralizing acid groups, and the aqueous solution of the 2-oxazoline polymer with a hydrophilic latex comprising a carboxy functional acrylic ester polymer, said solutions and latex being miscible with each other. In order to increase the opacity of the coated article, the surface of the substrate which is to be coated with the coating composition may first be coated with a pigment base coating and then overcoated with said coating composition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A coated article of the invention is produced by the steps comprising:
(a) providing a substrate;
(b) coating at least one surface of said substrate with an aqueous coating composition comprising an olefin copolymer containing substantially neutralized pendant acid groups and a 2-oxazoline polymer; and
(c) drying said coating.
What is meant herein by a 2-oxazoline polymer is defined in U.S. Pat. No. 4,678,833, the teachings of which are incorporated herein by reference. The preferred 2-oxazoline polymer of the invention is polyethyloxazoline having a molecular weight ranging from 1,000 to 1,000,000, with a molecular weight of approximately 500,000 being preferred. Polyethyloxazoline is produced by the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. Polyethyloxazoline is available from Dow Chemical Company, Midland, Michigan, and sold under the trademark "PEOX". The aqueous coating composition of the invention is preferably formed by mixing a solution of a 2-oxazoline polymer in an aqueous liquid with a solution of an olefin copolymer containing substantially neutralized pendant acid groups in an aqueous liquid. The solution of the 2-oxazoline polymer in an aqueous liquid preferably comprises between 10-30 weight percent polyethyloxazoline and between 70-90 weight percent water.
As used herein, the term aqueous liquid is meant to include water as well as a fluid comprising substantially water plus one or more organic components.
The preferred olefin copolymer containing pendant acid groups comprises polyethylene acrylic acid copolymer where the weight percent acrylic acid ranges from 10 to 30 weight percent and more preferably is 20 weight percent. Other suitable olefin copolymers containing pendant acid groups include ethylene methacrylic acid copolymer and the like. In order for the olefin copolymer having pendant acid groups to go into solution with an aqueous liquid and thus be mixed in that form with the aqueous solution of the 2-oxazoline polymer, it is necessary to add a base capable of substantially neutralizing the acid groups of the olefin copolymer. Suitable bases include ammonia and ammonia derivatives, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and amines. In order to reduce water sensitivity, a preferred base, such as ammonium hydroxide, will evaporate when the coating is dried. In this case, the olefin copolymer will regain its original level of hydrophobicity once the coating is dried. The preferred base, ammonium hydroxide, is preferably mixed with water to form an aqueous solution and then this aqueous solution of ammonium hydroxide is mixed with an aqueous liquid and the olefin copolymer containing pendant acid groups. The aqueous solution of ammonium hydroxide preferably comprises between 25-30 weight percent ammonium hydroxide and between 70-75 weight percent water. The aqueous solution of the olefin copolymer containing substantially neutralized pendant acid groups and the base is preferably formed by mixing between 20-30 weight percent polyethylene acrylic acid copolymer, between 70-75 weight percent water and between 1-5 weight percent aqueous solution of ammonium hydroxide.
The aqueous coating composition of the invention comprising a 2-oxazoline polymer and an olefin copolymer containing substantially neutralized pendant acid groups preferably comprises between 1 to 50 and more preferably 5 to 30 weight percent of the 2-oxazoline polymer and between 50 to 99 and more preferably 70 to 95 weight percent of the olefin copolymer containing substantially neutralized pendant acid groups, said weight percents being based on the weight of the 2-oxazoline polymer and the olefin copolymer. Accordingly, once dried, the coating preferably comprises between 1 to 50 and more preferably 5 to 30 dry weight percent of the 2-oxazoline polymer and between 50 to 99 and more preferably 70 to 95 dry weight percent of the olefin copolymer containing pendant acid groups, which pendant acid groups may or may not be substantially neutralized depending on the base used to neutralize the acid groups in solution, said weight percents being based on the weight of the 2 -oxazoline polymer and the olefin copolymer.
For certain applications, such as for making an aqueous ink-receptive coating for a spunbonded olefin which will not wash off with water, the coating composition preferably further comprises a carboxy functional acrylic ester polymer. It appears that in order to obtain the right amount of wettability, e.g., aqueous ink receptivity, with just the olefin copolymer having pendant acid groups and the 2-oxazoline polymer in the dried coating , it is necessary to use a large amount of the 2-oxazoline polymer, e.g., at least 20 to 50 percent by weight of the coating composition, said weight percents being based on the weight of the 2-oxazoline polymer and the olefin copolymer. Unfortunately, this large quantity of the 2-oxazaline polymer may cause the coating to be able to be washed off with water. Since a carboxy functional acrylic ester polymer will b1end with the olefin copolymer to make the coating more wettable, by adding the carboxy functional acrylic ester polymer to the aqueous coating composition, preferably in the form of a latex, a lesser amount of the 2-oxazoline polymer needs to be used in order to obtain the right wetting properties. Even though the carboxy functional acrylic ester polymer, similar to the 2-oxazoline copolymer, blends with the olefin copolymer to make it more wettable, once the coating is dried, the carboxy functional acrylic ester polymer will not go into solution with water and thus a coating comprising a 2-oxazoline polymer, an olefin copolymer having pendant acid groups and a carboxy functional acrylic ester polymer will not wash off with water. Suitable carboxy functional acrylic ester polymers include polyacrylate/acrylonitrile copolymers, polyacrylates, polyethylene vinyl acetates,polyvinyl acetates/acrylates, etc. and the preferred carboxy functional acrylic ester polymer comprises a polymer comprising acrylic acid, acrylonitrile and styrene.
The aqueous coating composition of the invention comprising a 2-oxazoline polymer, an olefin copolymer having substantially neutralized pendant acid groups and a carboxy functional acrylic ester polymer is preferably formed by mixing together: (1) an aqueous solution formed by mixing an olefin copolymer containing pendant acid groups with a base capable of substantially neutralizing said acid groups and an aqueous liquid; (2) an aqueous solution of a 2-oxazoline polymer; and (3) a hydrophilic latex comprising a carboxy functional acrylic ester polymer, said solutions and latex being miscible with each other. The hydrophilic latex, polymerized through free radical polymerization, preferably comprises between 45-50 weight percent of a polymer comprising acrylic acid, acrylonitrile and styrene; 1-5 weight percent surfactant and 45-50 weight percent water. A surfactant, preferably an anionic surfactant, is preferably included in the latex in order to better enable the carboxy functional acrylic ester to be dispersed in water. The aqueous coating composition of the invention comprising a 2-oxazoline polymer, an olefin copolymer containing substantially neutralized pendant acid groups and a carboxy functional acrylic ester polymer preferably comprises between 10 to 20 weight percent of the 2-oxazoline polymer; between 60 to 80 weight percent of the olefin copolymer containing substantially neutralized pendant acid groups; and between 10 to 20 weight percent of the carboxy functional acrylic ester polymer, said weight percents being based on the weight of the 2-oxazoline polymer, the olefin copolymer and the carboxy functional acrylic ester polymer. Accordingly, once dried, the coating preferably comprises between 10 to 20 dry weight percent of the 2-oxazoline polymer; between 60 to 80 dry weight percent of the olefin copolymer containing pendant acid groups, which pendant acid groups may or may not be substantially neutralized depending upon the base used to neutralize the acid groups in solution; and between 10 to 20 dry weight percent of the carboxy functional acrylic ester polymer, said weight percents being based on the weight of the 2-oxazoline polymer, the olefin copolymer and the carboxy functional acrylic ester polymer.
The aqueous coating compositions of the invention preferably comprise between 2-75 and more preferably 2-35 weight total solids. The coating compositions of the invention can be modified by the incorporation of fillers, thickeners and other such modifiers. Types and amounts of these materials can easily be determined by those skilled in the art. The coatings of the invention preferably comprise between 0-70 weight percent filler, examples of suitable fillers being fumed silica, clay, silicates and the like.
The aqueous coating composition of the invention can be coated onto any backing material (substrate) to which it will adhere when dry, such as paper, plastic, spunbonded olefins, nonwovens and metals. In making aqueous ink-receptive coatings, the coating weight is preferably about 0.01 to 5 ounces per square yard and the thickness of said coating is preferably between 0.01 to 5 mils. The coating composition can be applied to the substrate by any of the conventional coating techniques, such as reverse roller coating, rod coating, or air knife techniques. The coated substrate is dried by conventional means, for instance by air drying or by drying in a forced air oven.
When it is desired to increase the opacity of the coated substrate, the surface of the substrate which is to be coated with the coating composition is first coated with a pigment base coating composition, the pigment coated substrate is dried and then the pigment coated substrate is overcoated with the coating composition of the invention. The pigment base coating must have good adhesion to the substrate as well as good adhesion to the overcoating. Suitable pigments for the pigment base coating include titanium dioxide, satin white, calcium carbonate, talc, blanc fixe, zinc oxide, zinc sulfide, barium sulfate, colored pigments, etc., with the preferred pigment being titanium dioxide. The pigment base coating composition preferably comprises the pigment; water; a dispersing agent, such as tetra sodium pyrophosphate to enable the pigment to be disposed in water; and a thickener, such as methylcellulose, to keep the pigment from settling out; and a suitable binder for the pigment.
The invention is further illustrated by the following non-limiting example:
EXAMPLE
A white pigment dispersion in water is prepared by mixing together 80.0 lbs. of deionized water, 0.8 lbs. of tetra sodium pyrophosphate (a dispersing agent), 200 lbs. of rutile grade titanium dioxide pigment and 31.2 lbs. of a solution containing 5 weight percent methyl cellulose (thickener) and 9 weight percent water. The viscosity of said white pigment dispersion ranges between 600 to 1500 centipoise measured on a #3 Brookfield spindle at 60 rpm. A pigment base coating composition is formed by mixing 342.3 lbs. of this white pigment dispersion with 8.3 lbs. deionized water, 1 lb. Acrysol ASE-75, an acrylic copolymer thickener obtained from Rohm & Haas, and 398.4 lbs. of an ammoniated solution of Dow Chemical's Primacor 5980. Primacor 5980 is a polyethylene acrylic acid copolymer in pellet form having an 80/20 weight percent ratio of ethylene to acrylic acid. The ammoniated solution of Primacor 5980 is formed by mixing 25 weight percent Primacor 5980 with 72 weight percent water and 3 weight percent of a solution containing 28 weight percent ammonium hydroxide and 72 weight percent water. The purpose for the Primacor 5980 in the pigment base coating composition is to obtain good adhesion of the base coating to the substrate.
A Tyvek® substrate is coated with this pigment base coating composition. Tyvek® is obtained from Dupont - Wilmington, Delaware, and is a spunbonded olefin made from high-density polyethylene fibers. The pigment coated substrate is dried at between 150° F. to 225° F. in an oven for approximately three minutes and the dry pigment coating weight is approximately 0.25 oz/yd 2 . The drying temperature is particularly important since too high a temperature can cause permanent heat distortion in the substrate. The dry pigment coating is then overcoated with an aqueous ink-receptive coating prepared by mixing together 595 lbs. of the above-described ammoniated solution of Primacor 5980; 66.3 lbs. of Hycar 2600×84; 159.8 lbs. of a solution containing 20 weight percent PEOX 500 and 80 weight percent deionized water; and 28.9 lbs. of deionized water. Hycar 2600×84 is a lightly crosslinked, heat reactive latex obtained from B. F. Goodrich and believed to be a 48 weight percent solids dispersion of a polymer comprised substantially of acrylic acid, acrylonitrile and styrene in water containing an anionic surfactant. PEOX 500 is obtained from Dow Chemical and is a polyethyloxazoline resin having a molecular weight of 500,000. The solution of PEOX 500 is made by mixing 240 lbs. of deionized water with 60 lbs. PEOX 500 resin. The aqueous ink-receptive overcoating is then dried at 150° F. to 225° F. in an oven for approximately 3 minutes and the dry overcoating weight is approximately 0.40 oz/yd 2 .
The coated substrate obtained from the above procedure is calendered and then an aqueous-based ink is applied to the coated substrate by a printing method such as air brush, ink jet, xerographic, hand marking etc.
While this invention has been described with reference to its preferred embodiments, other embodiments can achieve the same result. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents as fall within the spirit and scope of this invention. | Disclosed are coating compositions, coated articles made using said coating compositions and processes for preparing the same. More particularly disclosed are aqueous ink-receptive, water-based coatings which are smudgeproof and which will not wash off with water. | 2 |
FIELD OF THE INVENTION
The present invention relates to a mechanism for bedding a receiver frame and/or a barrel in a stock of a firearm. In addition, the present invention also relates to a firearm comprising such a mechanism.
BACKGROUND OF THE INVENTION
In prior-art system beddings, a bearing component with bearing surfaces is inserted into a complementary recess on the stock where it is bolted or glued to the stock. In cases in which connection is implemented purely with bolts, however, a potential problem is that the connection between the stock and the bearing component may loosen, which can lead to a mutual displacement between the bearing component and the stock. If the bearing component is rigidly glued to the barrel, on the other hand, the bearing component can no longer be readily removed.
DE 84 09 468 U1 describes a mechanism for bedding a barrel in a stock of a rifle. The mechanism has a bearing component which, on its upper surface, has a support surface for receiving the barrel and a guide profile for seating the bearing component free from play in the stock on the lower surface. The guide profile has the shape of a wedge-shaped comb, the wedge surfaces of which rest free from play against the corresponding wedge surfaces of a wedge-shaped groove in an abutment made of steel.
SUMMARY OF THE INVENTION
The problem to be solved by one embodiment of the invention is to make available a mechanism for bedding a receiver frame and/or a barrel in a stock of a firearm, as well as a firearm comprising such a mechanism, in which the bearing component can be readily removed, yet allows permanent and reproducibly accurate positioning between the bearing component and the stock.
Beneficial improvements and useful advanced embodiments of the present invention are also set forth herein.
The mechanism disclosed by the present invention has a guide profile that is formed by downwardly projecting rib-like guide members which are designed such that they can be forced into the stock. During mounting, the guide profile engages in the stock which is made, e.g., of wood or plastic, and thus ensures an interlocking connection. Thus, lateral spread can be prevented and optimum system bedding and barrel fixation to ensure stress-free mounting in the stock can be achieved. An additional advantage of the mechanism disclosed by the present invention is that it is possible to mount a different receiver frame or barrel on the stock without additional fitting expenditures.
During mounting of the bearing component, the rib-like guide members that are disposed, e.g., along the edge of the bearing component are forced into the stock and ensure lateral guidance free from play. Because of the interlocking engagement of the rib-like guide members in the stock, it is possible to connect the stock to the receiver frame in such a manner that no displacement can occur and that reproducible accuracy is ensured for an accurate fixation of the barrel, without time- and cost-consuming preliminary preparative work on the stock.
In another preferred embodiment of the present invention, the rib-like guide members have a wedge-shaped cross section. Because of this special wedge shape, the rib-like guide members are forced into the stock, which can be made, e.g., of wood or of plastic, which has the effect of creating an interlocking connection that is free from play.
To support a hollow cylindrical front end of the receiver, the bearing surface can have the form of a prism-shaped support surface with oppositely slanted inside bearing surfaces on two rib-like bearing members that are disposed at a distance from each other. The bearing surface can also have the shape of a half shell or the like. If the front end of the receiver is not cylindrical, the bearing surface can also have a shape that conforms to the outer contour of the end of the receiver frame or of another part of the receiver frame.
Disposed on the bearing component, next to the bearing surface, is an abutment section with an abutment element for transmitting the forces of the recoil that act on barrel to the shaft when the shot is fired. The abutment element can be an adjusting spring that is disposed in the bearing component so as to engage in a transverse slot on the lower surface of the barrel or receiver frame.
BRIEF DESCRIPTION OF THE DRAWINGS
Other distinctive features and advantages of the present invention follow from the subsequent description of a preferred practical example that is based on the drawing. As can be seen:
FIG. 1 shows a longitudinal sectional view of a part of a repeating rifle with a barrel, a stock, a receiver frame or system and a mechanism for bedding the receiver frame in the stock;
FIG. 2 shows a cross section along line A-A seen in FIG. 1 ;
FIG. 3 shows an enlarged detailed view of area B seen in FIG. 2 ;
FIG. 4 shows a perspective view of the mechanism for bedding the receiver frame as seen from above; and
FIG. 5 shows a perspective view of the mechanism for bedding the receiver frame as seen from below.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a portion of a repeating rifle with a barrel 1 , a stock 2 , a system or receiver frame 3 and a mechanism 4 for bedding the system or receiver frame 3 in the stock 2 . The system or receiver frame 3 , here designed as a chamber sleeve, comprises a front end of the receiver 5 in which the back end of the barrel 1 comprising a cartridge chamber 6 and locking elements 7 is disposed.
The mechanism 4 for bedding the receiver frame 3 in the stock 2 , which mechanism is as separately shown in FIGS. 4 and 5 , has an essentially cubic bearing component 8 which, on its lower surface, has rib-like guide members 9 that can be forced into the stock 2 so as to ensure that the bearing component 8 is seated free from play in the stock 2 . Because of the rib-like guide members 9 which engage in the stock 2 so as to interlock with said stock, a guide profile for lateral guidance is created on the lower surface of the bearing component 8 . As the embodiment shown in FIG. 2 indicates, two parallel rib-like guide members 9 are disposed along the edges of the bearing component 8 . FIG. 3 indicates that the rib-like guide members 9 have a wedge-shaped cross section. Because of this special wedge shape, during mounting (which will be discussed in greater detail below), the rib-like guide members are forced into the stock 2 which is, e.g., made of wood or plastic, which leads to an interlocking connection between the bearing component 8 and the stock 2 that prevents lateral movement.
As FIGS. 4 and 5 indicate, the upper surface of the bearing component 8 has a posterior bearing surface for bearing the hollow cylindrical front end of the receiver 5 . In the embodiment shown, the bearing surface for bearing the front end of the receiver 5 is designed in the form of a prism-shaped bearing with two oppositely slanted inner bearing surfaces 10 on two rib-like bearing members 11 that are disposed at a distance from each other. It is, however, also possible for the bearing surface to have the shape of a half shell or the like. If the front end of the receiver is not cylindrical, the bearing surface can also have a shape that conforms to the outer contour of the front end of the receiver.
The upper surface of the bearing component 8 furthermore comprises an anterior abutment section 12 with an adjusting spring groove 13 that runs at right angles relative to the longitudinal axis of the gun. An upwardly projecting adjusting spring 14 is disposed in the adjusting spring groove 13 so as to be able to engage in a transverse slot 15 on the lower surface of the barrel 1 as shown in FIG. 1 . The posterior bearing surface with the slanted bearing surfaces 11 is designed to ensure that when the hollow cylindrical front end of the receiver 5 rests on the bearing surfaces 10 , the front end of the receiver 5 which is disposed on the barrel 1 does not rest against the anterior abutment section 12 . Only the adjusting spring 14 which is disposed in the anterior abutment section 12 engages in the lower transverse slot 15 of the barrel 1 so as to transmit the recoil forces via the adjusting spring 14 and the bearing component 8 to the stock 2 .
As FIG. 1 indicates, the adjusting spring 14 is held in place by a screw 16 which is disposed in a countersunk hole 17 that runs from the lower surface of the bearing component 8 to the adjusting spring groove 13 , with the threaded shaft 18 of said screw engaging in a complementary tapped hole 19 on the lower surface of the adjusting spring 14 . Between the two rib-like bearing elements 11 , an additional through-hole 20 , which again has the form of a countersunk hole, for a threaded bolt 21 and a threaded sleeve 22 is disposed so as to connect the bearing component 8 to the front end of the receiver 5 . The upper portion of the threaded bolt 21 is screwed into a threaded hole in the lower surface of the front end of the receiver 5 , and the upper end of the bolt engages in a cutaway section 24 of the stock 2 . The upper frontal area of the threaded sleeve 22 rests against an inside annular surface 25 of the through-hole 20 , which has the form of a countersunk hole. The threaded bolt 21 and the threaded sleeve 22 serve to screw the front end of the receiver 5 to the bearing component 8 .
The bearing component 8 is inserted into a complementary recess 26 of the stock 2 , and the threaded sleeve 22 , which also serves as a spacer sleeve, engages in a hole 27 in the stock. On the lower end of the hole 27 , a cutaway section 28 for receiving the front portion of a magazine frame 29 is disposed in the stock 2 . Screwed into the lower end of the threaded sleeve 22 is a screw 30 by means of which the magazine frame 29 can be secured in the cutaway section 28 and tightened to the lower surface of the stock 2 . In addition, as the screw 30 is being tightened, the screw 30 and the threaded sleeve 22 , which also serves as a spacer sleeve, force the bearing component 8 into the recess 26 and press it against the upper surface of the stock 2 , with the result that the rib-like guide members 9 are also forced into the stock 2 so as to create an interlocking connection. The interlocking engagement of the rib-like guide members 9 in the stock 2 leads to the desired lateral guidance.
The invention is not limited to the practical example described above. Thus, for example, it would also be possible to bed not only the front end of the receiver of a receiver frame which here is designed as a chamber sleeve, but also the barrel, or both, on the bearing component that has the guide profile disposed on it.
All references cited herein are expressly incorporated by reference in their entirety. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. There are many different features to the present invention and it is contemplated that these features may be used together or separately. Thus, the invention should not be limited to any particular combination of features or to a particular application of the invention. Further, it should be understood that variations and modifications within the spirit and scope of the invention might occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. | The present invention relates to a mechanism for bedding a receiver frame ( 3 ) and/or a barrel ( 1 ) in a stock ( 2 ) of a firearm, the mechanism having a bearing component ( 8 ) which can be attached to the stock ( 2 ) and which, on its upper surface, has a bearing surface ( 10,11 ) for bearing the receiver frame ( 3 ) and/or the barrel ( 1 ). To ensure permanent and reproducibly accurate positioning, the lower surface of the bearing component ( 8 ) comprises a guide profile ( 9 ) for seating the bearing component ( 8 ) free from play in the stock ( 2 ). | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to vehicle torque box chassis frames for supporting extendible aerial ladders, such a frame being particularly useful with firefighting vehicles.
2. Description of the Related Art
Firefighting vehicles such as ladder trucks include extendible aerial ladders whereby the ladders may be raised and extended in excess of one hundred feet, as may be required in fighting fires in multiple story buildings, or conducting rescues therefrom.
Commonly, extending aerial ladders are hydraulically operated whereby the ladder assembly may be lowered to a stored position, and raised to an operative position. The ladder system consists of a plurality of extension ladders, and when the ladders are extended, and partially raised, significant bending forces are applied to the frame of the support vehicle due to the weight of the ladders, and any personnel or equipment supported thereon.
In order to stabilize vehicles supporting extendible ladder systems, it is common to mount jack systems upon the vehicles which extend laterally from the vehicle sides and include hydraulically extendible jacks for engagement with the ground to stabilize these vehicles during ladder extension. Most jack systems are attached to the conventional vehicle structure, including the suspension system, and while such jack systems do greatly improve the vehicle stability during aerial ladder extension due to the high centroidal moment of inertia imposed upon the vehicle by an extended aerial ladder, the ultimate degree of stability desired has not been achievable, and the height of extendible aerial ladders has been limited due to the inability to provide as stable a ladder platform as possible.
Efforts have been made to improve the stability of aerial ladder platforms as formed on firefighting vehicles, as shown by the assignee's U.S. Pat. No. 4,570,973. In this patent an elongated torque box of generally rectangular transverse cross section utilizes a plurality of braces and webs to form a substantially rigid elongated box upon which the aerial ladder may be supported. However, due to limitations in the vertical dimensions of the torque box shown in U.S. Pat. No. 4,570,973, and structural limitations due to the relationship of the ladder supporting structure to the remainder of the torque box, optimum ladder supporting characteristics were not achieved.
SUMMARY OF THE INVENTION
Objects of the Invention
It is an object of the invention to provide an integral aerial torque box chassis frame which includes a turntable support for aerial ladders wherein the torque box is capable of withstanding high bending forces and provides a stable support platform for extended aerial ladders.
Another object of the invention is to provide an integral aerial torque box vehicle chassis free which includes a turntable support for aerial ladders wherein extendible jack structure is integrally formed with the torque box whereby the torque box may be directly supported upon the ground without influence from the vehicle suspension system.
Yet another object of the invention is to provide an integral aerial torque box vehicle chassis frame constituting a platform for extendible ladders wherein the torque box is supported upon integral jack structure to provide stability, and the torque box is open having an accessible rear end wherein ladders may be stored within the torque box at a readily accessible location and height.
An additional object of the invention is to provide an integral aerial torque box vehicle chassis frame which may be readily fabricated using conventional metal fabricating apparatus.
In the practice of the invention a pair of spaced parallel heavy duty channel members are used to form the lower region of the torque box, while a pair of elongated box cross section members are vertically disposed above the channel members a significant distance to provide sufficient resistance to bending moments. Bracing elements in the form of sheet steel are interposed between the upper and lower box and channel members located on a common side of the box, while the lower channel members are interconnected by a sheet steel bracing floor member. The upper members are preferably interconnected by obliquely disposed truss members who ends are welded to the upper members.
The rear end of the torque box constitutes a turntable support for the aerial ladder apparatus. The turntable support is integral with the other components of the torque box and includes a plurality of columns having a box transverse cross section for supporting the weight of the ladder assembly without deflection. The turntable support defines the rear end of the torque box, and is open in alignment with the length of the torque box chassis frame whereby the interior of the torque box is accessible through the turntable support and may serve as a chamber to receive ladders, or other equipment.
The torque box chassis frame includes jack receiving tubes for supporting hydraulic jacks. The front pair of the jack supporting tubes is located adjacent the front region of the torque box below the channel men,hers, while the rear pair of jack receiving tubes is located below the turntable support. The jack tubes are of a length perpendicularly disposed to the length of the torque box, and the jack structure arms located therein are capable of being laterally extended relative to the torque box length whereby the hydraulic jacks formed on the ends of the extendible arms may be lowered to engage the ground and directly support the torque box chassis upon the terrain.
Due to the rigidity of the torque box chassis frame, the support of the torque box on the terrain by the jacks bypasses the vehicle suspension, and actually raises the vehicle slightly with respect to the terrain whereby, during ladder operation, the entire vehicle may be supported upon the jacks.
A torque box chassis frame constructed in accord with the invention achieves a rigidity not heretofore attained, and provides a platform for an extendible aerial ladder assembly which permits aerial ladders to be extended to heights not previously possible.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:
FIG. 1 is a side elevational view of a firefighting vehicle utilizing the torque box chassis frame of the invention, the extendible ladder assembly being partially illustrated,
FIG. 2 is a side elevational view of the torque box chassis frame, per se,
FIG. 3 is a plan view of the torque box chassis frame of FIG. 2,
FIG. 4 is an elevational sectional view as taken along Section 4--4 of FIG. 3,
FIG. 5 is an elevational sectional view as taken along Section 5--5 of FIG. 3,
FIG. 6 is an elevational sectional view as taken along Section 6--6 of FIG. 3, and
FIG. 7 is a plan sectional view as taken along Section 7--7 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The overall environment of a fire truck torque body in accord with the invention is best represented in FIG. 1 wherein an entire fire truck vehicle is illustrated. The fire truck basic component is the frame or chassis 10 much of which forms the torque box construction of the invention. The frame is supported on front wheels 12 and dual rear wheels 14 which are attached to the frame 10 by conventional suspension structure 16 which may be formed by leaf springs, torsion springs or air bags, as is well known in the art. The truck cab 18 is located at the front end of the frame 10 and includes the engine and other vehicle control components, as well as providing an enclosure for the firemen during transportation. The usual pump structure 20 may be mounted upon the frame 10, and other apparatus may be mounted upon the truck frame as is commonly used with firefighting equipment.
As the inventive concept pertains to torque boxes used with aerial ladders an extendible ladder 22 is pivotally mounted upon the bracket 24 which is attached to the turntable 26 rotatably supported upon the torque box by conventional bearings, not shown. The vertical elevation of the ladder 22 is controlled by the extendible hydraulic cylinder 28 interposed between the bracket 24 and the ladder structure, as well known. The particular type of extendible ladder utilized with fire trucks employing the invention does not form a part of the invention, and conventional ladder arrangements may be used except that trucks utilizing the torque box of the invention may employ ladders of greater extendible length, and a greater number of sections, than extendible ladder assemblies previously employed with mobile fire truck platforms.
The frame 10 includes a section thereof designated as a torque box 30, the torque box constituting that portion of the vehicle frame upon which the majority of bending forces are imposed when the ladder 22 is extended.
The basic components of the frame 10 are a pair of substantially parallel channel members 32 which extend the length of the vehicle. The members 32 are in spaced relationship to each other and the wheels 12 and 14 are located below the members 32 and support the members through the wheel suspension apparatus.
The torque box 30, in addition to the members 32, is defined by the elongated box members 34 located vertically above the rear portions of the channel members 32 as will be appreciated from FIGS. 1 and 2. Vertical bracing colons 36 are interposed between the members 32 and 34 as being welded thereto, and the lateral sides of the torque box 30 are defined by a sheet metal plate 38 extending between the members 32 and 36 at each side of the torque box and the metal plate 38 is welded to the members 32 and 34, as well as to the columns 36. In this manner the sheet metal plate 38 rigidly interconnects the members 32 and 34 in a vertical direction, and the columns 36 which are also welded to the plate 38 prevent the plate 38 from buckling. A sheet metal bottom plate 40, FIGS. 5 and 6, extends between the upper ends of the channel members 32 wherein the plates 38 and plate 40 define a U-shaped configuration closing in the sides and bottom of the torque box 30.
The upper portion of the torque box is defined by a plurality of truss bracing members 42, FIG. 3, which extends between the box members 34 having shaped ends whereby the men%bets 42 are welded to the box members 34. By the use of the bracing members 42 the torque box 30 is now defined of a rectangular cross sectional configuration having the lateral side bracing plates 38, the bottom plate 40, and the upper truss bracing members 42.
At its front end the torque box 30 is defined by wedge shaped plates 44 extending from the box members 34 to the upper edges of the channel members 32, and the plates 44 are welded to the associated structure to further define an integral assembly.
At its rear end, the torque box 30 is defined by the ladder turn table support 46. The turn table support 46 is defined by lateral sheet plate sides 48 located between four steel box beam columns 50, FIG. 7, welded to the channel members 32 and extending thereabove. The plate sides 48 are also welded to the columns 50, and the columns 50 are also welded to the plates 38. At its upper end, the turn table support 46 includes a rectangular frame 52 formed of steel box beams, and a thick two inch steel plate 54 having the circular opening 56 is welded to the upper turn table frame 52. As the frame 52 is welded to the columns 50 and sides 48, the turn table support 46 constitutes an integral rear end of the torque box 30 so that all forces imposed upon the ladder turn table support 46 will be directly imposed upon the torque box 30. The ladder support structure, not shown in detail, is mounted upon the plate 54 and extends into the opening 56, and such support structure may include bearings, a large gear, motor, and other apparatus for rotating the ladder turn table 26.
When extending the ladder 22 in a vertical direction, it is necessary that the ladder platform be solidly supported upon the ground, and such support is achieved through hydraulic jacks rigidly associated with the frame 10 and torque box 30.
The jacks are mounted within outrigger supports of a rectangular configuration for supporting the jack structure. The outrigger support tubes are best illustrated in FIGS. 2 and 3.
A pair of front or forward jack support tubes 58 are welded to the underside of the channel members 32 at a location directly below the wedge plates 44. The tubes 58 are of an elongated configuration as will be appreciated from FIG. 3, and the length thereof is at right angles to the length of the torque box and channel members 32. The rear jack tubes 60 are also welded to the underside of the channel members 32, and are located directly below the turntable support 46. Bracing fillets 62 may be interposed between the jack tubes and the channel members 32 to prevent twisting or displacement of the jack tubes.
Hydraulic jack arm structure of a known type generally represented at 64 is supported within the front tubes 58, and at their outer ends the jacks include vertically disposed hydraulic cylinders 66 having pistons supporting a foot pad which engages the terrain. The jack arms located within the front tubes 58 extend in an outrigger manner in opposite directions from the torque box 30 to provide lateral support of the front portion of the torque box in either direction.
In a like manner, jack arm structure 68 is located within the rear tubes 60 and include cylinders 70 having foot pads located at the lower end of the cylinder pistons for engaging the terrain, the jack arms 68 being extendible in opposite directions from the torque box 30 in the same manner as the front jacks 64.
Also, a pair of front drop and lock jacks 74 are rigidly mounted on frame 10 by brace gussets 76 which are vertically adjusted by cylinders 78.
In practice, the vertical height of the torque box plates 38 is approximately thirty-six inches, and the separation of the channel members 32 and box members 34 is approximately 36 inches, while the separation of the channel members 32 is of substantially equal dimension, and as the plates 38, the bottom 40, and the truss bracing members 42, as well as the turn table support sides 48, columns 50 and frame 52 all define a large hollow box beam, the torque box 30 is capable of withstanding very high bending forces with minimal deformation as imposed thereon by the weight of the ladder assembly 22. As the jacks 64, 68 and 74 are directly connected to the torque box 30 the support of the torque box and ladder assembly is directly by the terrain, and the vehicle suspension is bypassed and is not a part of the ladder support. Accordingly, the torque box 30 is directly supported upon the terrain and as the jacks 64 and 68 can be longitudinally laterally extended within their tubes 58 and 60, respectively, a wide, rigid, broad base support for the torque box 30 is provided.
On uneven terrain, the extension of the cylinders 66, 70 and 78 may actually lift the rear wheels 14, and/or front wheels 12, from the terrain, depending upon the degree of the grade. However, upon the jack cylinders being raised, and retracted into their associated tubes, the weight of the vehicle frame 10 will be supported by the wheels and their associated suspensions.
As will be appreciated from FIGS. 5 and 6, the configuration of the torque box 30 is such that a rectangular space 72, FIG. 6, is located between the plates 38 and above the bottom plate 40, and this space is open at the rear through the turn table support 46 whereby ladders, hose, or other equipment may be readily stored within the space 72 of the torque box 30, and easily and rapidly removed therefrom for use.
The rigidity and stability of the torque box 30 utilizing the aforedescribed concepts per, nits a heavier and longer ladder assembly 22 to be mounted upon a vehicle than heretofore possible, and the practice of the invention provides increased firefighting and rescue capabilities.
It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention. | A torque box chassis frame for firefighting vehicles or the like constituting a platform for extendible aerial ladders. The vehicle torque box chassis frame includes elongated lower and upper members significantly spaced from each other having rigid bracing structure interposed therebetween resulting in a rigid elongated box of significant rectangular cross section dimension. The torque box chassis frame rear end is defined by a rigid ladder turntable support including its own vertical rigid columns, and spaced outrigger support tubes for receiving hydraulic outrigger jacks are integrally defined on the torque box chassis frame to provide firm support of the torque box upon the ground eliminating the influence of the vehicle suspension system. | 4 |
RELATED APPLICATION
This application is a continuation of PCT/US2011/053925 filed Sep. 29, 2011 which claims the benefit of U.S. provisional application No. 61/388,168 filed Sep. 30, 2010 the disclosures of which are hereby incorporated herein by reference in their entirety.
FIELD OF INVENTION
The field relates to detection kits using reagents for detection of chemical compounds, such as drugs and explosive compounds, for example.
BACKGROUND
Detection kits are known that use reagents for detecting chemical compounds by changes in contrast, color or the like. A variety of reagents are very well known for detecting one or more chemical compounds or classes of chemical compounds.
SUMMARY OF INVENTION
A detection kit comprises a plurality of swabs, each of the plurality of swabs having the form of a stick, being bundled together in a single test kit for detection of a plurality of chemical compounds. For example, five detection sticks are bundled together in a single test kit. A user can open the kit, swab a surface or surfaces with the bundled sticks, collecting chemical constituents to be tested, such as powders, on the detection surfaces of each of the sticks, enclose the bundled sticks into a reaction chamber, and rupture an ampoule in the reaction chamber to release a fluid that initiates a chemical reaction at the detection surface, if compounds to be detected are present on one or more of the detection surfaces. For example, an adhesive is present on one or more of the detection surfaces that allows easy collection of powders from a surface to be swabbed.
In one example, the detection kit has a transparent reaction chamber or transparent cover, allowing the user of the kit to observe any color change on the detection surfaces. For example, a transparent cover may be placed over the detection surfaces of the bundled sticks, enclosing the bundled sticks within the reaction chamber without obscuring a view of the detection surfaces. In one example, the transparent cover may be locked into place once the bundled sticks are enclosed by the cover inside of the reaction chamber. In an alternative example, a mechanism for rupturing of an ampoule in the reaction chamber locks the transparent cover in place, as well, sealing the bundled sticks within the reaction chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
The examples illustrated in the following drawings and the detailed description are examples of the invention for the purpose of illustrating features of the invention to be recited in the claims of an issued patent and are not limiting to the scope of the inventions claimed.
FIG. 1 illustrates an example of a detection kit including five detection sticks arranged in a detection kit, with a transparent cap removed from the detection kit.
FIG. 2 illustrates the same detection kit with the transparent cap enclosing the detection kit, after the rupture of an ampoule, showing a color change indicating the presence of
FIG. 3 illustrates the arrangement of five chambers within a partial view of the body of the detection kit for insertion of the five detection sticks and a central device for breaking of one or more ampoules in each of the detection sticks.
FIG. 4A illustrates an exploded view of the detection kit, absent the transparent cover, showing a rotary mechanism for breaking of the one or more ampoules in each of the five detection sticks.
FIG. 4B illustrates an alternative example of a rotary mechanism similar to FIG. 4A .
FIGS. 5A and 5B illustrate a single detection stick disposed in relation to a rotary mechanism shown in (A) a partial cutaway view and (B) a partially exploded cutaway view, which is similar to the examples in FIGS. 4A and 4B , except in FIG. 5 the rotary mechanism is design to rupture two ampoules in each detection stick by forcing both the top and bottom portions of the segmented rupture mechanism to spread outwardly.
FIG. 6 illustrates an exploded view of the detection kit, showing a push button mechanism for breaking of the one or more ampoules in each of the five detection sticks.
FIG. 7 illustrates a portion of the detection kit showing the mechanism for rupturing one or more of the ampoules of the detection sticks (two shown) in a first position,
FIG. 8 illustrates an enlarged view of the example in FIG. 7 .
FIG. 9 illustrates the example of FIGS. 7 and 8 in a second position, after a segmented rupturing device, central to the five ampoules, is expanded, resulting in the rupture of one or more ampoules in the detection sticks (only two shown in this cutaway view).
FIG. 10 illustrates an enlarged view of the example in FIG. 9 .
FIG. 11 illustrates an alterative example of a detection kit in a position causing rupture of one or more ampoules in the detection sticks.
FIG. 12 illustrates a cross-sectional view of the example illustrated in FIG. 11 .
FIG. 13 illustrates a partially-exploded, cross-sectional view of the example illustrated in FIG. 11 , identifying a housing, one or more detection sticks (only two oppositely disposed detection sticks shown in this cross-sectional view), and an integrally-formed displaceable cap and ampoule crushing mechanism.
FIG. 14 illustrates the example of FIG. 11 in a first position, prior to rupture of one or more ampoules in the detection sticks.
FIG. 15 illustrates an exploded, perspective view of an example having six detection sticks, two of the six detection sticks having a co-joined wicking swab.
FIG. 16 illustrates another example of an assembled detection kit.
FIG. 17 illustrates an exploded, perspective view of the example in FIG. 16 .
FIG. 18 illustrates a partial cross-sectional view of the exploded view in FIG. 17 .
FIG. 19 illustrates a cross-sectional view of the assembled detection kit in FIG. 16 .
DETAILED DESCRIPTION
FIG. 1 illustrates an example of a detection kit including five detection sticks arranged in a detection kit, with a transparent cap removed from the detection kit. Each of the detection sticks 16 , 18 may comprise a flexible outer shell 21 containing one or more ampoules that are capable of being ruptured by a rupture mechanism, such as the segmented rupture mechanisms disclosed in the examples, below. When the ampoule or ampoules of the detection sticks are ruptured, the contents are released and are transported to the detection surface of the detection stick by way of wicking, gravity, capillarity or otherwise, such as by way of a wicking tip 23 inserted into the flexible outer shell 21 . The detection surface of each detection stick may have an adhesive applied to the surface, which may be a porous layer 19 that covers the entire detection surface of one of the detection sticks 18 or may be provided in a pattern, such as the dots 17 shown on one detection sticks 16 of the detection kit 1 . A latching mechanism 8 may be provided on the transparent cap 7 , such that the cap becomes fixed on the body 5 of the detection kit 1 , when the cap is snapped onto the body prior to rupturing of the ampoules. The latching mechanism 8 may be disposed on the inner side of the cap 7 , such that it engages a notch 11 formed in the body 5 of the detection kit, for example. One or more such latching mechanisms may be provided on the cap, such that the cap can be initially removed for swabbing of the detection surfaces on a surface to be tested, but when rotated to the locking position with the arrows 9 , 12 aligned, the cap locks into position on the body.
FIG. 2 illustrates the same detection kit with the transparent cap enclosing the detection kit, after the rupture of an ampoule, showing a color change indicating the presence of a compound to be detected. The arrows 9 , 12 are aligned and the notch 11 is engaged with the latching mechanism 8 .
FIG. 3 illustrates the arrangement of five outer flexible shells 21 of five detection sticks within a partial view of the body 5 of a detection kit 1 and a central device for breaking of one or more ampoules in each of the detection sticks.
FIG. 4A illustrates an exploded view of a detection kit 1 , absent the transparent cover, showing a rotary mechanism for breaking one ampoule in each of the five detection sticks. A rupturing mechanism 40 is illustrated in an exploded view showing a spreading nut 41 , having threaded inner surface 42 of a bore engageable by a threaded surface 43 on the end of a member 44 joined to a handle capable of being used for rotating the shaft. The threaded surface on the end of the member is threadingly engaged in the bore of the spreading nut, when the detection kit is assembled. In one example, the end of the member is engaged in the bore such that it is capable of rotating; moving the nut downward on the shaft, but the end is not disengageable from the nut by rotating in the opposite direction. For example, the shaft is first inserted through the bore of the nut, and the threaded end portion is then joined to the shaft prior to threadingly engaging the threaded end portion in the bore of the spreading nut. The spreading nut 41 is capable of engaging segmented rupture members 47 extending from a base 46 , which may be plate-like. A detection stick retainer 49 may be provided with a hole for fitting over the rupture members 47 and may be shaped to accommodate a plurality of the detection sticks 16 , 18 . In one example, the detection sticks are adhered to the retainer 48 , such as by gluing or potting the detection sticks within the retainer.
FIG. 4B illustrates an alternative example of a rotary mechanism similar to FIG. 4A . In this example, the retainer 49 and base 46 are joined together. For example, the base and retainer may be adhered or integrally formed.
FIGS. 5A and 5B illustrate a single detection stick disposed in relation to a rotary mechanism shown in (A) a partial cutaway view and (B) a partially exploded cutaway view, which is similar to the examples in FIGS. 4A and 4B , except in FIG. 5 the rotary mechanism is design to rupture two ampoules in each detection stick by forcing both the top 53 and bottom 59 portions of the segmented rupture mechanism 50 to spread outwardly when the handle 45 of the rotary mechanism is rotated. A flexible sleeve 51 is shown in FIG. 5A , which holds individual segments 54 of the segmented rupture mechanism 50 together. The end 59 of the member attached to the handle 45 is shown extending beyond the nut 41 . The spreading nut 41 spreadingly engages the end 53 of the rupture mechanism 50 when the handle is rotated. Also, the opposite end 59 engages a spreading post 52 , which is fixedly attached to the base 46 . resulting in the spreading of the opposite ends 59 of the segments 54 when the handle 45 is rotated. Thus the ends 53 , 54 rupture both of the ampoules 55 , 57 disposed in each of the plurality of detection kits, as shown in this example. The reactants mix and are transported to the wicking end 23 of the detection sticks 18 and through the adhesive layer 19 or to the powder or other compounds stuck to the patterned adhesive, for example. In FIG. 5B , the spreading post 52 is illustrated in an exploded view, showing the inclined surfaces at one end of the spreading post that engage similarly sloped surfaces of the opposite end 59 of the rupture mechanism 50 .
FIG. 6 illustrates an exploded view of the detection kit, showing a push button plunger 60 for breaking of the one or more ampoules in each of the plurality of detection sticks 18 . In this example, the rupture mechanism and base are integrally formed with the body 5 of the detection kit 1 . The detection sticks are disposed in the body 5 and may be potted or otherwise fixed in the body. The plunger 60 may be integrally formed with a push button 61 on one end of a shaft 62 and a retention tip 64 on an opposite end of the shaft of the plunger 60 . In FIG. 7 , the retention end 64 is shown engaged with the rupture end 71 of the rupture mechanism 70 . which is integrally formed with the body 5 of the detection kit 1 . An expanding surface 63 is capable of spreading the rupture ends 71 of the segmented rupture mechanism 71 , as illustrated in the drawing of FIG. 9 . The retention end 64 is illustrated in a partial cross sectional, cutaway view in FIG. 8 . In one example, the retention end is inserted through the rupture ends 71 prior to inserting disposing the plurality of detection sticks within the body of the kit. Then, the detection kits are disposed in the body of the kit, positively locking the plunger 60 in the kit. When the plunger is pressed, such as by the user's thumb, toward the body 5 of the kit, the inclined spreading surface 63 of the plunger engages the rupture ends 71 of the segmented rupture mechanism 70 , forcing the ends 71 into contact with the ampoules and rupturing the ampoules, releasing the contents, such as reagents for detecting chemical compounds. In one example, a Griess reagent is used for detecting nitrates. In another example, 4-(dimethylamino)cinnamaldehyde (DMAC) is used for detecting urea nitrate. In yet another example, a molybdate reagent is used for phosphate detection. In still another example, Nessler reagent is used for the detection of ammonium nitrate or an ammonium ion thereof. For example, a combination of one or more of the foregoing may be used in a detection kit described in the examples. FIG. 10 shows a detailed view of the rupture ends 71 superimposed over the ampoules 55 , showing that the ampoules would be ruptured when the plunger 60 is pressed.
FIG. 11 illustrates another example of a detection kit comprising a plurality of detection sticks. In this example, an integrated cap and rupture mechanism 107 fits conformingly over a housing 105 that contains the plurality of detection sticks. The cap 107 may be transparent to allow the visual detection of a color change on the end of one or more of the plurality of detection sticks. Two holes 106 , 109 in the cap 107 may be engaged by a raised bump 108 disposed on a surface of the housing 105 , providing a first position for the cap 107 prior to rupture of any ampoules of the detection sticks and a second position after compression of the cap 107 onto the housing 105 between a thumb and a finger of a user to cause the ampoules to rupture. As illustrated in the example of FIG. 12 , an ampoule 121 within a flexible sleeve 21 is capable of being ruptured by a rupture mechanism 140 arranged such that the rupture mechanism 140 squeezes each of a plurality of ampoules 121 between the inner wall of the housing 105 and the rupture mechanism 140 , when the cap 107 is compressively engaged on the housing 105 , moving the cap 107 from a first position illustrated in FIG. 14 to the rupture position illustrated in FIG. 12 . An ampoule releases one or more fluids, such as a reagent or solvent or both a reagent and solvent, that may be wicked by the wicking tip 23 to a porous adhesive layer 19 or to adhesive dots 17 , for example. The adhesive layer or dots may be disposed on a surface of the wicking tip 23 , with “on” being defined broadly to mean in contact with a surface of the wicking tip 23 and may be adhesively adhered to the surface. Preferably, the adhesive layer and dots are tacky and capture powders, particles and other contaminants located on a surface swabbed by the plurality of wicking tips 23 . Each ampoule may have one or more volumes for containing the one or more fluids, which may be either premixed or separated, such as in breakable ampoules.
For example, separate detector sticks 16 , 18 , 118 are illustrated in FIG. 13 , each having a single, separate ampoule 121 , for example. Alternatively, more than one ampoule may be coupled together to contain more than one fluid separated from the other. One detector stick 18 in the partial cross-sectional view of FIG. 13 is illustrated disposed partially obscured behind a cross-sectional view of a detector stick 16 , for example, in an arrangement accommodating six detector sticks. The cap 107 comprises an integrated rupture mechanism 140 and dividers 141 dividing the wicking tip 23 of one detector stick 16 from the wicking tip 23 of the adjacent detector stick 18 , for example. The integrated dividers 141 may prevent mixing of fluids from one ruptured ampoule 121 with a neighboring ruptured ampoule in the adjacent detector stick 18 .
The illustration of FIG. 15 shows an arrangement of six detector sticks, as arranged in a single housing 105 , for example. A slot 111 may be aligned with protrusion on the cap 107 , such that the cap 107 may only be aligned in one way. For example, this may be necessary if a pair of adjacent detector sticks 116 have wicking tips 123 joined together. For example, two different fluids may be disposed in two different ampoules, which may mix when wicked by the wicking tip 123 to the co-joined detection surface of the pair of adjacent detector sticks 116 . Two or more detector sticks may be joined together for presenting a plurality of reagents and/or solvents as necessary to induce a visual change on the surface of the detector sticks, when a target chemical is present at the surface due to swabbing of the surface of the wicking tip on a contaminated surface, for example.
Target compounds may include drugs, explosives or precursors of compounds that may be combined, such as urea nitrate, ammonium nitrate, other nitrates, urea, phosphate fertilizers and the like. The housing may be made of a low density polyethylene, may be opaque and/or may have instructions. An instruction sheet may include a peel-off label for annotation of date, time, location, conditions and the like. The cap may be a transparent plastic material, such as a polycarbonate, acrylic, urethane or the like, such that the detection surfaces of the detector sticks are visible through the cap. The housing may have color indicators identified in relation to the physical location of detection surfaces of the detector sticks, such that the user can quickly compare the detection surface to the color indicator to determine if there is a positive indication for the presence of one of the target compounds, for example. The detection surfaces may have an adhesive, either a porous layer or dots of adhesive, and/or a solid or gel reagent immobilized on the detection surface. The solid or gel reagent may be capable of directly detecting liquid, mist or vapor phase compounds. A solvent, such as alcohol, water or the like, or a liquid reagent could be released by the rupture of a reservoir in the detection sticks, for example, which could lead to a reaction at the detection surface by the solid phase reagent and a target compound or a liquid phase reagent and a target compound or a plurality of reagents, solid and/or liquid, and one or more target compounds, for example.
FIG. 16 illustrates yet another example, using a push rod 201 to activate rupture of a rupture mechanism 240 , for example. FIG. 17 illustrates an exploded, perspective view of a detector kit 200 showing the push rod 201 insertable into a rupture mechanism 240 integrally molded with the housing 205 . Six detector sticks are arranged circumferentially within the housing 205 around the rupture mechanism 240 . A cap 207 includes an ergonomically-shaped compression surface 270 shaped to accommodate a thumb, finger or fingers within a concave cavity. The cap 207 may be transparent to allow visual observation of a change in color or other indication of the presence or absence of a particular contaminant, such as based on a chemical reaction between a target composition and a reagent, solvent or the like provided by the detector kit 200 . The push rod 201 may have an ergonomical compression surface 202 , such as the concave shape illustrated in FIG. 18 , for example. A bulbous tip 210 engages a constriction 244 of the rupture mechanism 201 , as illustrated in FIG. 19 , retaining the push rod 201 within the detector 200 , during storage and transport, for example. The rupture mechanism 240 comprises a plurality of fingers 242 preferably numbered and arranged to contact each of a plurality of the detector sticks when plunged into the detector 200 under compression by a user of the kit. For example, a slit 241 may separate each of the plurality of fingers 242 , allowing the flexibility of the fingers to bend radially outwardly. When the push rod 201 is plunged by compression of the concave surface 270 of the push rod 201 toward the concave surface 270 of the cap 207 , such as by compressing between a thumb and one or more fingers of a user's hand, then a conically-shaped portion 211 of the push rod 201 engages the constriction 244 of the rupture mechanism 240 forcing the fingers 242 of the rupture mechanism 240 radially outward, contacting and rupturing each of the plurality of ampoules 121 in each of the detector sticks 118 , for example.
As in the previous examples, simultaneous rupturing of each of the ampoules releases a fluid that is wicked by the wicking tips 23 to the detection surfaces that are swabbed on or across surfaces that may have the presence of one or more target compositions that are to be detected, if present. The cap 207 may include dividers, as in the other examples, which may prevent cross-contamination of fluids from one wicking tip 23 to another. Alternatively, two or more wicking tips may be joined to encourage the transfer of fluid from one wicking tip to the other.
The claims are not limited to the examples, and features of the examples may be combined or modified by a person having ordinary skill in the art, based on this description and the drawings provided. The examples are provided to show various arrangements and features, and the arrangement and features in one example may be combined with the arrangement and features of other examples. For example, the ergonomically designed cap and housing of one example may be implemented in the other examples without undue experimentation, based on teachings provided in this disclosure. | A detection kit comprises a plurality of swabs, each of the plurality of swabs having the form of a stick, being bundled together in a single test kit for detection of a plurality of chemical compounds. A user opens a detection kit, swabs a surface or surfaces with the bundled sticks, collecting chemical constituents to be tested on detection surfaces of each of the plurality of sticks. Liquids, mists, vapors and powders may be tested in one method, utilizing one or more dry reagents on the detection surfaces. The sticks may comprise a volume of fluid, releasably contained within the sticks, such that when activated, a fluid, such as a reagent or solvent, is wicked by a wicking tip to the detection surface of the stick. For example, a mechanism is provided that is capable of breaking a vial or ampoule containing the fluid, when activated by a twisting motion or compression. Adhesive may be present on one or more of the detection surfaces. A transparent reaction chamber may be provided by a transparent cover or cap. | 8 |
RELATED APPLICATIONS
This application claims the benefit under 35 USC 119(e) of U.S. Provisional Application Nos. 61/035,479, filed on Mar. 11, 2008 and 61/035,481, filed on Mar. 11, 2008, both of which are incorporated herein by reference in their entirety.
This application relates to U.S. application Ser. No. 12/401,750 filed on Mar. 11, 2009.
BACKGROUND OF THE INVENTION
X-ray imaging has become an important part of our lives since its invention in the 19th century. The imaging techniques that are used in medical imaging and security inspection systems are usually projection systems that record the shadow radiograph behind the subject. In the 1980s, microscopy techniques based on x-ray lenses have emerged to dramatically improve the resolution of x-ray imaging to tens of nanometers.
The majority of these x-ray imaging systems use traditional table top electron-bombardment x-ray sources, but sources with much higher brightness and different spectral characteristics have also been used to expand the capabilities of x-ray imaging techniques. In particular, synchrotron radiation sources provide highly collimated beams with 6 to 9 orders of magnitude higher brightness and tunable narrow bandwidth. In additional to dramatically improving the microscopy throughput, the synchrotron sources also enable spectral microscopy techniques that are able to selectively image specific elements in a sample. These developments have resulted in powerful microscopy techniques with unique capabilities that are not found with other technologies.
On drawback of synchrotron radiation facilities is the relatively long down-time compared with tabletop x-ray sources. While a tabletop source can typically run continuously between annual or semi-annual maintenance intervals, synchrotrons typically require more frequent maintenance intervals with long shutdown times. These maintenance requirements lead to excessive down-time of x-ray imaging instruments.
SUMMARY OF THE INVENTION
A solution for integrating a tabletop x-ray source to the x-ray microscope imaging system so that it can be used to power the instrument when the synchrotron x-ray beam is not available is described. A typical setting is where imaging system will be stationed at a synchrotron radiation facility and normally performs the imaging operations using the high brightness synchrotron radiation. However, when the synchrotron is not in operation, e.g., during maintenance periods, the imaging system will operate with an alternative self-contained x-ray source such as a table-top x-ray source.
Because different x-ray sources offer different emission characteristics such as spatial coherence and spectrum, some beam conditioning systems must be used. They include different types of optical elements to control the beam collimation and energy filters.
The above and other features of the invention including various novel details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular method and device embodying the invention are shown by way of illustration and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:
FIG. 1 is a schematic diagram of a synchrotron-based x-ray microscope that includes an integrated table-top x-ray source along with its energy filtering system with a mechanical translation system that switches between the two x-ray sources.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows x-ray microscope system 100 using a table-top source 52 and synchrotron source 50 according to the principals of the present invention.
Synchrotrons generate highly collimated x-ray radiation with tunable energy. They are excellent sources for high-resolution x-ray microscopes. The x-ray radiation 54 generated from the synchrotron 50 is controlled and aligned by the beam-steering mirrors 56 . It then reaches a monochromator 58 to select a narrow wavelength band. The monochromator 58 is typically gratings or a crystal monochromator to disperse the x-ray beam 54 based on wavelength. When combined with entrance and exit slits, it will select a specific energy from the dispersed beam. The energy resolution will depend on the grating period, distance between the slits and grating, and the slit sizes.
Also included is the table-top x-ray source 52 . Typically this source is a rotating anode, microfocus, or x-ray tube source.
Either of the table-top x-ray source 52 and the synchrotron 50 provides a radiation beam 62 to an x-ray imaging system 64 . For high resolution applications, the imaging system 64 is a microscope, which includes sample holder, for holding the sample, an objective lens for forming an image of the sample and a detector for detecting the image formed by the objective lens. In one example, a zone plate lens is used as the objective lens. A compound refractive lens is used on other examples. In the preferred implementation, the imaging system 64 is full-field imaging x-ray microscope, but in other examples a scanning x-ray microscope is used.
The monochromator 58 is usually used to produce a monochromatic beam in order to satisfy energy bandwidth requirement of the imaging system 64 . For example, commonly used objective lenses in x-ray microscopy are Fresnel zone plate lenses. They provide very high resolution of up to 50 nanometers (nm) with higher energy x-rays above 1 keV and 25 nm for lower energy x-rays. Since these lenses are highly chromatic, using a wider spectrum will lead to chromatic aberration in the image. Zone plates typically require a monochromaticity on the order of number of zones in the zone plate lens. This is typically 200 to several thousand, thus leading to a bandwidth of 0.5% to 0.05%. This energy selection process of the monochromator 58 typically makes use of a small portion of the x-ray radiation generated by the source and rejects the rest of the spectrum from the synchrotron 50 .
In contrast, emissions from a table-top x-ray sources typically contain a sharp characteristic emission line superimposed on a broad Bremsstrahlung background radiation. The characteristic emission line typically contains a large portion the total emission, typically 50-80%, within a bandwidth of 1/100 to 1/500. In order to create a monochromatic radiation, an absorptive energy filter system 66 is used to remove unwanted radiation from the table-top x-ray source 52 and only allow a particular passband. Two filters are often used: one to absorb primarily low energy radiation below the characteristic line and one to absorb energies above the emission line. This filtering system provides a very simple way to condition the beam but at a cost of some absorption loss of radiation.
Alternatively, a monochromator system can also be used in the filter system 66 . This typically contains a grating or multilayer to disperse the x-ray radiation and an exit slit to block unwanted radiation.
The source switching system requires monochromatization devices for both synchrotron radiation source 50 and table-top x-ray source 52 . In most applications, the synchrotron beam monochromator 58 is built into the beamline and the monochromator/filters 66 for the table-top source 52 are integrated into the x-ray source 52 or the switching system 110 .
Synchrotron radiation typically has much higher spatial coherence, i.e. too highly collimated, than is suitable for a full-field imaging microscope and must be reconditioned using beam conditioning optics 60 that modify the x-ray characteristics to meet the requirements of the x-ray imaging system 64 . Typical methods to reduce the coherence use a diffusing element such as polymers arranged in random directions or a rotating element. This approach is very simple to implement but has the disadvantage of loosing significant amount of radiation intensity.
Alternatively, the conditioning optics 60 use a set of two mirrors that first deflect the beam off axis and then reflect the deflected beam toward to focal point on axis. This set of mirrors is allowed to rotate rapidly about the optical axis to create a cone shaped beam illumination pattern that will provide increased divergence.
In some examples, the beam conditioning optics 60 include diffractive element(s) such as a grating and Fresnel zone plate lenses or reflective elements such as ellipsoidal lenses or Wolter mirrors. Compound refractive lenses can also be used.
Another method to increase the beam divergence is to use a capillary lens as the conditioning optics 60 to focus the beam towards the focal point. This method provides a simple means of modifying the collimation of the beam. The capillary lens can be scanned rapidly in a random pattern. Finally, a grating upstream of the capillary lens can be used to further increase the beam divergence.
The beam coherence of the beam 70 of laboratory source 52 is very different from that of synchrotron 50 . Table-top sources behave like point sources so that radiation emitted is roughly omni-directional. With these types of sources a simple capillary lens is preferably used as a condenser 68 to project the source's radiation towards the sample. The capillary lens is generally designed in an ellipsoidal shape with the x-ray source and sample at the foci.
The switch system 110 contains the condenser optics 68 for the table top source 52 and the conditioning optics 60 for the synchrotron 50 . Both optics are contained in the switching system and switched along with the x-ray sources. The switching system 110 includes a mechanical positioning system that is integrated to ensure reliable repositioning of each optics after each switching action. This switching system 110 is based on a combination of kinematic mounting systems, mechanical stages, electromechanical motors, optical encoders, capacitance position measurements, etc.
The system 110 switches between the synchrotron source 50 and table-top x-ray source 52 with a mechanical translation system that replaces the conditioning optics 60 with the table-top source 52 , energy filters 66 and condenser 68 in beam axis to the imaging system 64 . The table-top x-ray source 52 and its energy filters 66 and condenser optics 68 are integrated in a single assembly 112 and mounted on a motorized translation stage of the system 110 with optical encoders. The conditioning optics 60 for the synchrotron beam is mounted at opposite end of the mechanical translation stage. Therefore, the switching action can be made by a simple translational action, see arrow 114 .
In some systems with a vacuum connection, the conditioning optics 60 for the synchrotron beam will also contain provisions for the optics and possibly the microscope to operate in vacuum.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. | An x-ray imaging system uses a synchrotron radiation beam to acquire x-ray images and at least one integrated x-ray source. The system has an imaging system including sample stage controlled by linear translation stages, objective x-ray lens, and x-ray sensitive detector system, placed on a fixed optical table and a mechanical translation stage system to switch x-ray sources when synchrotron radiation beam is not available. | 7 |
BACKGROUND OF THE INVENTION
The invention concerns a method for the measurement of off-center rotating components of a measured object, whereby the measured object is supported in a rotatable fashion and rotates about a rotational axis and a measurement plane is defined perpendicular to the rotational axis within which the part of the measured object to be measured is irradiated with a parallel beam emanating from a radiative source, and having a detecting means for recording the silhouette of a cross section through the measured object in the measurement plane produced by the radiative source and the measured object, as well as an apparatus for carrying out the method.
An apparatus and a method of this kind have become known in the art by means of the international publication WO86/07442.
The method and apparatus which are known in the art are suitable for determining the dimensions of an elongated measured object. An optical electronic measuring station is proposed for the automatic dimensional control of outer rotating components by means of which the object to be measured is illuminated from below by an linear radiative source in order to produce an image of two diametrically opposed contour points on two linear photodiode arrays. The resulting intensity discontinuities give the two contour points and the shaft diameter can be determined by the electronically recorded separation between the two diode cells.
FIG. 1 shows the fundamental principle of the measurement in accordance with prior art. A radiative source 1 produces a beam 22 comprising parallel rays which illuminates an object to be measured 2 along an optical axis 8. The elongated measured object 2 rotates about a rotational axis which runs through the center 7 perpendicular to the plane of the drawing. A detecting means 3 comprises two separated detector elements 5, 5' whose separation with respect to each other is movable by means of a positioning means 4. Since the beam 22 comprises parallel rays, the position of the beam on the detector 5 produces a silhouette having an intensity profile. The sampled change in the intensity in the vicinity of the edge of the measured object allows, in concert with the electronically determined separation between the two detector linear photocell arrays 5, 5', for a precise dimensional measurement of the measured object. A repeated measurement of the diameter during the rotation facilitates a determination of the roundness of the measured object. With an apparatus in accordance with prior art the resolution for the diameter measurement assumes a value of one micron and the longitudinal precision assumes a value of 0.002 mm. With this apparatus it is possible to measure shafts in the diameter range from 7 to 100 mm having a length from 200 to 700 mm.
Although the measured diameters and roundnesses can be determined quite precisely, the apparatus and the method in accordance with prior art have the disadvantage that asymmetric measured components can not be measured to the required precision, since the rotation of such a component leads to errors in the measurement.
It is therefore the purpose of the present invention to improve an apparatus and a method of the above mentioned kind in such a fashion that rotating components having an asymmetric stroke support position can be measured sufficiently accurately.
SUMMARY OF THE INVENTION
This purpose is achieved in accordance with the method of the invention in that the rotational axis position is adjusted between the detecting means and the beam in such a fashion that the off-center rotating component which is to be measured is illuminated and initially, with a stationary detecting means, the maximum excursion of a diameter of the off-center rotating component is determined by means of a silhouette projection onto the detecting means, an angle of rotation of the off-center rotating component is determined, and the detecting means is synchronized with the position of the angle of rotation and moved parallel to the beam in such a fashion that the separation, parallel to the beam, between the detecting means and the rotating off-center component is kept constant.
The purpose of the invention is likewise realized by means of an apparatus for carrying out the method which exhibits: means for positioning the measurement plane so that it intersects the off-center rotating component to be measured, an angle measuring device to determine an angle of rotation of the off-center rotating component, a stroke means, which is configured in such a fashion that it can move the detecting means parallel to the beam, a synchronizer which synchronizes the stroke motion of the detecting means with the angular position of the off-center component and a computer to store, control and evaluate, whereby the detecting means are moved in such a fashion that the separation parallel to the beam, between the detecting means and the rotating off-center component is kept constant.
In this fashion the purpose of the invention is achieved. By means of a determination of the angular position of the rotating off-center component and by means of a synchronization of this angular position with a position of the detecting means movable parallel to the beam direction, the above mentioned measurement errors due to the changeable positions within the measuring optics can be avoided. During the rotation, an arbitrary point on the off-center rotating component to be measured exhibiting a given constant separation from the rotational axis describes a sinus-shaped motion relative to the optical axis while rotating in a circle about an off-center rotational axis. By means of a corresponding sinus-shaped motion of the detecting means relative to the rotational component, it is possible to maintain its separation, parallel to the beam, from the off-center rotational axis. By means of the measurement of the off-center rotating component at various angular positions during the rotation, it is possible for differing silhouette projections to be recorded, whereby the roundness of the off-center rotating component can also be determined.
It is particularly advantageous when the method is utilized to measure crank shafts. Such an application has the advantage that precision measurements of crank shafts can also be carried out automatically without mechanical contact.
It is also advantageous when the method is carried out to measure crank shafts having a plurality of off-center rotating components with a plurality of angles of rotation relative to each other. A utilization of the measurement procedure for the measurement of crank shafts of this kind has the advantage that even crank shafts having a complicated composition of off-center rotating components and exhibiting various angular positions with respect to each other can be measured automatically and without mechanical contact.
A particularly advantageous embodiment of the apparatus for carrying out the method utilizes two linear photodiode arrays to measure the off-center rotating component. This embodiment has the advantage that the advanced technology of CCD-cameras and laser scanners can be taken advantage of, whereby a plurality of individual measurements per rotation can be carried out.
In a variation of this embodiment, the apparatus exhibits a positioning means in order to adjust the separation between the two linear photodiode arrays. This variation has the advantage that even off-center rotating components with very differing diameters can be measured through the utilization of two adjustable linear photodiode arrays.
An advantageous embodiment of the apparatus for carrying out the method exhibits a positioning device in order to position the detectors transverse to the beam. This embodiment has the advantage that differing edges of the rotating off-center component can be detected at differing angles of rotation during the rotation so that the roundness of the off-center rotating component can also be determined.
Further advantages can be derived from the description and the accompanying drawings. The various features which are to be described can be utilized in other embodiments either individually or in arbitrary combination.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a brief description of the measurement principle in accordance with prior art;
FIG. 2a shows a cross section in a plane perpendicular to rotational axis of an off-center rotating component to be measured;
FIG. 2b shows a side view of the rotating component to be measured of FIG. 2a with accompanying rotation and detection components;
FIG. 3a shows a side view in the measurement plane where the off-center component to be measured lies on the optical axis at maximum separation from the radiative source;
FIG. 3b shows a representation of the measurement configuration for the case where the off-center component to be measured assumes an angle of 90° relative of that of FIG. 3a during rotation;
FIG. 3c corresponds to the configuration of FIGS. 3a and 3b but for the case where the off-center rotating component to be measured is on the optical axis and as close as possible to the source;
FIG. 4 shows a schematic representation of the connections between control components and the synchronized components in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 describes the fundamental principle of the measurement in accordance with prior art. A radiative source 1 produces a largely parallel beam 22 which irradiates an object 2 to be measured in such a fashion that a silhouette is created on a detecting means 3 equipped with a detector 5, 5'. The vertical position of the detector 5, 5' as well as the separation between possible detector portions 5, 5' is adjusted by means of a transverse positioning means 4.
The roundness of the measured object 2 can be determined by a rotation of the measured object 2 about a rotational axis which runs perpendicular to the plane of the drawing through the rotation center 7 together with an analysis of the intensity discontinuities in detector 5, 5'. An optical axis 8 defines the parallel travel direction of the beam through the rotation center 7. A transverse axis 6 cuts the optical axis 8 in a perpendicular direction through the rotation center 7.
Although, due to the parallel optical path of the beam 22, the measured results, for example with regard to the diameter of the measured object 2, are largely insensitive to small displacements in the direction of the optical axis, large displacements of the measured object along the optical axis cause optical distortions which falsify or degrade the measured results. Consequently, when executing a measurement of a measured object having a off-center rotating component, it is initially not possible to carry out a precise measurement of the off-center rotating component without undertaking additional measures.
FIG. 2a shows a cut in the measurement plane corresponding to the plane of the drawing of FIG. 1 of an object to be measured 2 having an off-center rotating component. The off-center rotating component 10 rotates, in this embodiment, about the rotation center 7 on an off-center stroke circle 13. In many cases, for example in the case of a crank shaft, a point 11 on the edge of the off-center rotating component also describes a circular motion about the rotation center 7 during the rotation of the measured object. In this fashion the off-centered rotating component also exhibits its own off-center rotation center 12 which, for its part, describes an off-center stroke circle 13 about the rotation center 7. During the rotation the off-center rotation center 12 exhibits a changing angle a relative to the transverse axis 6 which, for its part, is perpendicular to the optical axis 8.
FIG. 2b shows a side view of the apparatus. The measured object 2 is supported in a rotatable fashion between rotation means 15 in such a manner that a rotation in the rotation direction 16 about the rotational axis 18 is carried out. During the rotation the off-center rotational axis 19 and the off-center component 10 describe a cylindrical motion about the rotational axis 18 so that a cylinder-shaped surface is swept-out during a rotation of the off-center component. An optical housing 9 is arranged in the vicinity of the off-center component 10 in such a fashion that a precise measurement of the diameter or the roundness of the off-center rotating component 10 can be carried out. A rotational axis positioning means 21 adjusts the position of the optical housing 9 along the rotational axis 18. An angle measuring device 14 is arranged in such a fashion that the angular position or the angle of rotation α of the rotating off-center component is recorded in real time. The measuring plane 17, in which the cross sections according to FIGS. 2a, 3a, 3b and 3c lie, is indicated in FIG. 2b.
In the event that a measurement is carried out in the measurement plane 17 the following steps are executed in accordance with FIGS. 3a, 3b, 3c. FIG. 3a shows the contents of the optical housing 9 having a radiative source 1 which produces the parallel beam 22. During the rotation of the measured object, the off-center component 10 describes an off-center stroke circle 13 about the rotation center 7, whereby a separation d, parallel to the optical axis 8, obtains between the off-center rotation center 12 and the detector 5, 5'. The rotating off-center rotation center 12 is, in FIG. 3a, located precisely on the optical axis 8. Via the transverse positioning means 4 the detectors 5, 5' of the detecting means 3 are positioned in such a fashion that the silhouette of the off-center component 10 which is produced by the projection of the beam 22 is recorded with the detectors 5, 5'. The detectors 5, 5' are suitable for detecting the radiation from the radiative source 1 and the intensity profile of the silhouette. The intensity measurements of the detector in the shadow of the off-center component 10 are, with the exception of a possible small background, zero. Outside of the shadow the intensity naturally corresponds to the complete intensity of the source. Consequently, a sharp intensity profile change occurs precisely at that position where the projection of the edge of the measured object onto the detector plane 5, 5' is produced. The separation d is adjusted by means of a stroke means 20 which will be further described below.
During the rotation the position of the off-center component moves, for example, into the position shown in FIG. 3b. In FIG. 3b the rotating off-center component 10 is precisely in the vertical position, e.g. the off-center center 12 lies on the transverse axis 6. If then, via the transverse positioning means 4, the detectors 5, 5' of the detecting means 3 are adjusted in such a fashion that the sharp intensity change of the silhouette can be detected, a silhouette profile corresponding to the diameter of the measured object is imaged on the detector 5, 5'. The angular position a between the off-center center 12 and the transverse axis 6 (see FIG. 2a) then has, in this position, a value α=0 and, consequently, the off-center rotating component 10 has moved in the direction towards the radiative source 1. Stroke means 20 is, however, adjusted accordingly so that the detecting means are displaced towards the radiative source in such a fashion that the separation d is maintained or kept constant. In this manner optical distortions due to a changing separation between the detector and the off-center component to be measured are avoided.
If one continues to rotate further in accordance with FIG. 3c, then the off-center component 10 is located in a position having an angle of rotation α=270°. The stroke means 20 displaces the position of the detecting means 3 towards the source in such a fashion that the separation d between the off-center rotation center 12 and the detector 5 remains constant. In the event that detector configuration 5, 5' is changed via the transverse positioning means 4 in such a fashion that the silhouette of the off-center component can be detected, a measuring result in accordance with FIG. 3c can be utilized, in combination with FIG. 3a and 3b, to record three diameter measurements of the off-center component 10 and to thereby check the roundness or the eccentricity. The transverse positioning means 4 is also suitable for changing the separation between the two detector parts, for example 5, 5', so that objects of most differing diameters can also be measured.
FIG. 4 shows a schematic diagram of the cooperation and control between the differing components of the system. The synchronizer 30 is connected by means of conductor 47 to the rotation means 15 as well as to the angle measuring device 14 via conductor 43. A connection 44 between the synchronizer 30 and the stroke means 20 allows for the stroke means 20 to be adjusted in such a fashion that the separation parallel to the optical axis 8 between the off-center rotating component and the detecting means is kept constant. The position of the angle of rotation is detected by means of the angle measuring device 14. Additional connections 45 and 42 are shown in FIG. 4 between the synchronizer the transverse positioning means 4, and the computer 40, respectively. Connection 45 facilitates a synchronization of the transverse positioning means 4 with the angle measuring device 14 so that a motion perpendicular to the optical axis, e.g. parallel to axis 6, can also be synchronized with the rotation of the off-center rotating component. Synchronization information is stored via conductor 42 and computer 40. Computer 40 stores, controls and evaluates information. The angle of rotation position a is stored via conductor 41 and the intensity profile of the silhouette detected by detector 5, 5' is read out or stored via conductor 46 or 46'. Clearly, additional conventional connections between the computer 40 and the various components of the system in accordance with FIGS. 2 through 3c are possible in order to effect an automatization of the measuring process.
It is possible, with the method and apparatus in accordance with the invention, to monitor diameters and to measure diameters with a precision of approximately 1 micron. Measurements of this type can, for example, be carried out on measured objects having lengths between 0 and 3000 mm and having diameters between 0 and 1000 mm. Measurement of off-center rotating components can be carried out on, for example, crank shafts. The detecting means 5, 5' can have photocells connected to an optical CCD camera or a laser scanner. With a pixel read-out frequency of, for example, 10 MHz, a sample frequency of 5 KHz is to be expected. With a measured object rotational frequency of 1 Hz, 5000 samples per rotation are possible. Stroke throws of the off-center rotating component of, for example, ±200 mm can be measured with this method and with this apparatus. | An apparatus and a method are presented in order to carry out an automatic optical inspection of an off-center rotating component to be measured. Using a measurement procedure which avoids mechanical contact having a source producing parallel rays and a detecting means, the off-center rotating component is rotated about a rotational axis, whereby a motion of the detecting means is synchronized with the rotation and is carried out in such a fashion that the separation, in the direction of an optical axis, between the off-center rotating component and the detecting means remains constant. In this manner optical distortions are avoided which would otherwise occur in the optical measurement procedure. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to the securing of heavy wire fences to posts. These types of fences are commonly used commercially and for other purposes requiring sturdy partitioning.
A difficulty in erecting such fences is encountered when securing the attaching clips to the different parts of the fence. Such clips are made of a heavy band of metal and require substantial effort to secure fence wires to posts such as used in gates.
Tools available to secure fence clips prior to this invention have been cumbersome to use and have not secured the clips as tightly as desired. Because of this lack of facility in securing fence clips, prior tools have been time-consuming in use. Thus, the time required to use these tools made extensive commercial use economically undesirable.
In order to solve these problems and to provide other advantages the subject invention was developed.
SUMMARY OF THE INVENTION
This gate making tool includes a hooking rod and a clip bender rod pivotally mounted together near one end. The positioning of this mounting pivot is such that the shorter end portions of these rods are shaped to provide gripping jaw action relative to each other as the handle portions of each of the rods are moved.
The gripping area of one of said jaws is formed as a concavely curved hemisphere shaped to conform with the curvature of a round gate post thereby providing a post holding jaw.
Also hingedly attached to an enlarged outer portion of this post holding jaw is a smaller fence clip holding stretch hook provided with an inwardly curved end adapted to hold a fence attaching clip around a fence wire.
The other jaw is provided with a small end roller in its gripping section to provide a smoothly engaging clip bending jaw. Also, an inner roller near the pivotal mounting of the rods provides a roller bearing surface in the back inner portion of the jaw. Thus, in use, the post holding jaw's inwardly curved portion is against a fence attaching clip mounted on a fence post and with the other end of the fence attaching clip engaged by the clip holding stretch hook. The fence attaching clip is curved around the outside of a fence post and pressed into locking engagement by the small end roller of the pressing clip bender jaw as the handles are closed.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric side elevational view of the subject clamping device.
FIG. 2 is a fragmented bottom elevational view of the clamping device shown engaging and securing a fence clip around a fragmented portion of a fence wire and fence post.
FIG. 3 is a fragmented side elevational view of the clamping device as taken through plane 3--3 in FIG. 2 showing the fence starting to be engaged.
FIG. 4 is a view as in FIG. 3 with the jaws of the clamping device closed to secure a fence clip in place.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, the basic elements of this invention include an elongated clip bender element and an elongated hooking element pivotally mounted together by a hinge pin 20. The hooking rod is formed as two spaced, matching, parallel aligned sections joined together by bridge brackets 22 and 24.
The longer sections of the hooking element form a hooking handle made up of handle elements 26 and 28 on one side of hinge pin 20 and concavely curving post holding jaw elements 30 and 32 on the other side of pin 20.
Secured within the curved inner edges of jaw elements 30 and 32 are split jaws 34 and 35, respectively, which are curved to conform with the circumferentially curved shape of a fence post 36. Each of the jaw elements 30 and 32 includes a portion formed as enlarged stretch hook pivot humps 37 and 38, respectively, on the outside of the jaws 34 and 35. Extending between these stretch hook pivot humps 37 and 38 is a stretch hook pivot 40 axially in a plane parallel with the axis of pin 20 and mounted so as to pivotally carry stretch hook 42.
Stretch hook 42 extends out like a curved finger matingly adapted to engage the curved outer end of a fence clip 44, which is, in turn, curved to engage a fence wire 46. Hook 42 is capable of pivoting through the space between the split jaws 34 and 35 and extends out beyond them.
Clip bender element is formed with a clip bender handle 50 which can be moved adjacent to the hooking handle elements 26 and 28 when the clip bender element is pivotally joined thereto by hinge pin 20. In size, handle 50 is somewhat shorter than hooking handle elements 26 and 28 and slightly narrower so that it can be moved to a closed position between hooking handle elements 26 and 28 limited by pressing against bridge elements 22 and 24.
Forward of hinge pin 20 the clip bender bar is formed as a relatively straight arm forming a clip bender jaw 52 which can be pivotally moved toward the post holding jaws 34 and 35 when the handles are pressed together. On the forward end of clip bender jaw 52 a pressure roller 54 is mounted for rotation. This roller 54 provides a means for applying smooth and firm pressure against a fence clip without damaging galvanized outer surfaces.
Mounted forward of hinge pin 20 within the jaw engaging area, but generally to the rear of post holding jaws 34 and 35, is a guide roller 46 mounted for rotation between the separated, spaced elements of the post holding bar.
The elements of this invention are shaped and spaced relative to each other so that, in use, a portion of a wire fence can be readily secured to a gate post by tightly clamping a metal fence clip around the adjacent parts. Thus, as best shown in FIG. 2 the small hook end of a fence clip 44 (which is to be attached around a fence wire 46) is engaged within the curved end finger of the stretch hook 42. The remainder of the fence clip 44 is laid over a fence post 36 which is also engaged by jaws 34 and 35. The fence clip 44 is held in place by inner bearing pressure of guide roller 56 next to the fence post 36. The extended outer end of the fence clip 44 is engaged by the pressure roller 54.
Thus, as the hooking handle and clip bending handle are grasped and closed together this moves the clip bender 52 to press against the clip 44 and bend it tightly around a fence post 36 as shown in FIG. 4. This smooth rolling pressure of the bearing element rollers 54 and 56 in combination with the pivotal stretch hook attachment and conformed holding arrangement of the hooking jaws provides a tightly controlled engaging action for uniquely securing fence hooks.
The a particular form of this invention has been shown and described in detail herein this is meant as illustrative of this development and not as a limitation thereof which comprehends all embodiments within the spirit of the following appended claims. | A clamping device specially structured to provide conformingly shaped jaws and precisely positioned, leveraged fingers adapted to bend metal fence-attaching clips into locking position around adjacent portions of wire fences and round gate posts. | 8 |
It is well known that a textile machine, such as, for example, a circular knitting machine must be supplied under very constant tension with yarn which unwinds from suitable supports such as cones, bobbins and the like. If this is not the case, the textile article manufactured possesses defects (scores, bars, looped yarns and the like), which make it difficult to sell and may even cause it to be rejected. Very frequently the yarns do not unwind evenly from the supports in question and give rise to sudden changes in tension, because they are jammed, embedded or possess structural defects which make them catch onto one another during the unwinding process, and the like.
It is true that these disadvantages have been overcome to a certain extent by placing tension smoothing apparatus in the path of the yarns, between their supports and the textile machine fashioning them, the precise function of such tension smoothing apparatus being to absorb the unevennesses in tension generated as the yarns are unwound, in order to make it possible for the textile machine to be supplied with yarns under constant tension. French Pat. Nos. 1,345,166, 1,550,026, 1,589,997 and 1,593,374, inter alia, describe such means. In general terms, these means consist of rotating components which are controlled independently of the textile machine, are interposed between the supports and this machine, and on which there is continuously stored a certain optimum yarn reserve coming from the supports which is discharged continuously into the machine. It is thus a very small amount of yarn which is continuously supplied and used. In a case of excessive tension of the yarn, there is a fault in the supply of yarn to the rotating component of the feed device, but the latter continues nonetheless temporarily to discharge yarn to the machine, by drawing on its reserve. Thereafter, when the fault has been corrected and when normal working conditions have been resumed, the rotating component of the feed device is again supplied with the optimum amount and the original conditions apply once more. Thus, the machine is protected from sudden changes in tension of the yarn during the unwinding process since these sudden changes in tension are compensated for by the smoothing device in question.
One of the disadvantages of such devices resides in the fact that the slightest excessive tension during the unwinding of the yarn causes total stoppage of the installation, both of the textile machine itself and of the rotating component of the feed device storing the yarn reserve. It is only when the fault in the steady supply of yarn from its support has been corrected, as a result of manual intervention by the operator, that it is possible to again start both the intermediate rotating component of the feed device (often simply called the "feed device") and the textile machine itself. All this results in a loss of time, a lowering of the productivity of the machine, excessive consumption of energy in starting the moving parts, quite considerable fatigue for the operator, and the like.
SUMMARY OF THE INVENTION
The purpose of the present invention is essentially to restrict the manual intervention operations to those cases where intervention is really necessary, and consequently to increase the productivity of the combination, to reduce the work of personnel, and the like, and to do all this, of course, without in any way affecting the quality of the textile article to be formed.
The process according to the invention is based on the observation that:
In a large number of cases, the excessive tensions which arise while the yarn is being unwound from its support are of very low intensity, and consequently require an extremely short period of time, less than a limit hereafter called the "short limit", for them to be overcome by a given force, and hence it is not necessary to stop the operation of the textile machine which derives its supply from the yarn reserve of the rotating component of the feed device, which is started again automatically when the excessive tension has ceased and reforms its reserve. In another substantial proportion of cases, although the excessive tensions are of somewhat greater magnitude, they can in their turn be overcome, still for a given force, before the end of a slightly longer period of time, hereafter called the "middle period of time", so that, over the period exceeding the short limit, the textile machine also ceases to operate so that it does not empty the reserve of the feed device, the textile machine, like the rotating component of the feed device, being started again automatically when the excessive tension during the unwinding process has been overcome. Finally, in the small number of remaining cases, comprising very great excessive tensions of yarn during the unwinding process, serious cases of yarns being caught on one another, breakage of the yarn and the like, the moving parts are allowed to stop and the necessary manual interventions are made before starting the combination again when desired, doing so in a gradual manner, as is necessary.
In other words, this process for continuously supplying a textile machine, such as a circular knitting machine, with yarn under constant tension, the said yarn being stored transiently, also continuously and in optimum amount, is characterized in that, in a case of excessive tension arising while the yarn is being unwound and lasting for a period at most equal to the short limit (for example 3/10ths of a second), the store of yarn ceases to be maintained at its optimum amount, and that, in a case of excessive tension which lasts for a period longer than the above but at most equal to the middle limit (for example 3 to 30 seconds), in addition the machine ceases to be supplied with yarn, the re-storing of the yarn to its optimum amount and indeed the re-supplying of the machine with yarn being resumed as soon as the excessive tension during unwinding has been overcome.
It is not possible to give exact figures for the values of the short limit and the middle limit, these elements depending on numerous factors such as, especially, the nature, gauge and presentation of the yarn, the speed of the textile machine and the size of the yarn reserve on the feed device. It can be stated, however, that in the most common cases, the short limit can be 3/10ths of a second and the middle limit at least 3 seconds and preferably approximately between 5 and 30 seconds.
A device for carrying out this process, suitable for circular knitting machines equipped with feed devices including a rotating component which stores an optimum yarn reserve which is continuously discharged, positioned between the yarn support and the machine, comprises:
A first micro-contact-breaker with a delayed action, which, should excessive tension of the yarn arise during the unwinding process and last for a period at most equal to the short limit, is actuated by the yarn under excessive tension and stops the controls of the movement of the rotating component (feed device), while the inertia forces of this rotating component succeed in overcoming the excessive tension force; when this micro-contact-breaker is no longer subject to the action of the yarn, it then again starts the controls of the movement of the rotating component (feed device) which again builds up the store of yarn to its optimum reserve; and
A second micro-contact-breaker with a delayed action, which, in a case of excessive tension of the yarn lasting for a period between the short limit and the middle limit, is actuated by the yarn and stops the controls of the knitting machine, the yarn reserve stored on the feed device being sufficient to supply the machine; as above, when this micro-contact-breaker is no longer subject to the action of the yarn under excessive tension, it again starts the controls of the movement of the machine.
An improved knitting machine, of the type comprising a supply bobbin-carrying creel, a rotating component acting as a yarn feed device possessing a reserve, supplying the yarn to the knitting head, a component for controlling the rotational movement of the feed devices, a component for controlling the knitting head, and a micro-contact-breaker with a delayed action situated between the creel and the feed devices and connected to the components for controlling the rotational movement of the feed devices and the movement of the knitting head, is characterized in that the micro-contact-breaker consists of:
A micro-contact which successively controls the stopping of the component for controlling the rotational movement of the feed devices and the stopping of the component for controlling the movement of the knitting head;
an arm which moves about a fixed axis, carrying at one free end a guide through which the yarn passes; and
means for transmitting the oscillations of the arm to the micro-contact.
BRIEF DESCRIPTION OF THE DRAWING
The way in which the invention can be carried out and the advantages which result therefrom will become more apparent from the example embodiment which follows and which is given by way of illustration and without implying a limitation, with reference to the attached drawings.
FIG. 1 shows, in cross-section and diagrammatically, a circular knitting machine which operates according to the invention.
FIG. 2 concisely represents the electrical system for controlling such a machine.
FIGS. 3 and 4 illustrate a micro-contact-breaker according to the invention.
FIGS. 4A-4C schematically illustrate positions A, B and C of arm 23.
FIG. 5 shows the circuit diagram for controlling the various control components.
FIG. 6 is a diagrammatic representation of the elements for controlling the various control components.
FIG. 7 shows the elements of FIG. 4, in perspective.
DETAILED DESCRIPTION
The yarn to be knitting 1 (see FIG. 1) unwinds off the end of a bobbin-support 2 placed on a creel 3 positioned on the ground, passes through a conventional tensioning device 4 comprising discs, and then optionally passes through a monitor 5 which detects the presence of yarn, for example of the TRIPLITE type. The path of only one yarn has been represented in FIG. 1, it being understood that on a machine there are as many devices according to the invention as there are feeders. Likewise, only one creel 3 has been represented, but, depending on the type of machine, this creel can be formed from several separate parts surrounding the machine or from a single combination carried by the top of the machine (umbrella creel). The optional yarn detector 5 which checks for the presence of the yarn and, in its absence, causes the machine to stop by acting on the control box 14, can be placed either before or after the feed device 8; however, the safety of the combination is improved by placing it on the creel 3.
On issuing from the detector 5, the yarn is conveyed on the arm 7 of the micro-contact-breaker 17 (see FIGS. 3 and 4), and then reaches the feed device 8 which is placed above the circular knitting machine 9. There is always one feed device per feeder, for example 48 feed devices for a machine with 48 feeders. This feed device is of a type which is in itself known, for storing the yarn in an intermediate position, temporarily and continuously. A negative feed device of the SFS type, constructed by AB-IRO, P.O. Box 54, 52301 Ulriceham, Sweden, is preferably used, in which the stop function due to excessive tension has been removed by locking the appropriate screw. Such a feed device is described in the patents mentioned in the introduction.
On leaving the feed device 8, the yarn to be knitted then optionally passes through a positive feed device 10, for example of the type with belts, which operates at a constant rate (feed device of the BF type supplied by AB-IRO), and then reaches the knitting head 11 which forms the tubular fabric 12 which is taken up at 13 in a known manner.
The frame of the knitting machine 9 carries (see FIG. 2) an electrical panel 14 for controlling the various functions of the knitting machine (stopping, operating at low speed and operating at normal speed).
This panel 14 is connected by electric wires (see FIG. 5) first to the panel 15 which controls the feed devices 8 and which is placed, for example, on the creel 3 or on the machine 9 itself, and second to the panel 16 which controls the automatic operations (such as starting of feed devices and/or the knitting machine, starting of the machine at a slow speed then fast) and then if the over-tension exceeds the middle period of time, panel 16 prohibits the automatic starting of the machine.
The micro-contact-breaker 17 (see FIGS. 3 and 4) is of the type X 1 P 20 supplied by CEM (Compagnie Electro-Mecanique, 210, Avenue Felix-Faure, 69003 Lyon, France). This micro-contact-breaker 17, which acts for a single yarn position, is mounted on a U-shaped aluminum crossbar 18 placed on top of the creel 3, and possesses a push-button 19 which passes through a hole in the crossbar 18. This micro-contact-breaker 17 is connected by an electric wire 20 to a luminous indicator 21 which, should the machine stop, indicates the position at which the operator must intervene.
A fixed shaft 22, for example made of steel, is placed above the push-button 19 of each position and parallel to the crossbar 18.
A brass arm 23 (FIG. 4) carries, at one end, a yarn-guide 24, for example made of sintered ceramic, and, at its other end, a counterweight 25 which can slide on the arm 23. This arm 23 is fixed by means of a screw 26 to an eccentric cam 27, for example made of stainless steel, mounted loose about the fixed shaft 22 and held in position on the latter by circlips which are not represented, placed on either side of the shaft 22. The profile of the cam 27 is calculated so that, in a first stage, when there are normal excessive tensions during the unwinding process, the arm 23 can cause the cam to rotate about the fixed shaft 22 without engaging the push-button 19, and so that, in a second stage, the cam engages the push-button 19 when the movement of the arm 23 caused by the pressure of the yarn on the yarn-guide 24 reaches a pre-determined threshold.
The micro-contact 17 of the micro-contact-breaker 6 is connected by an electric wire 28 to the box 16 which controls the delaying operations and which is placed, as already stated, on the creel 3 (see FIG. 5). This control box 16 is connected in turn first by the wire 29 to the box 15 which controls the feed devices, and second by the wire 31 to the box 14 which controls the machine. The box 15 which controls the feed devices is connected by a wire 30 to the box 14 which controls the machine.
The delaying action panel 16 (FIG. 6) consists of:
A contactor 32, of the type KOS-8/40 (24-50) supplied by CEM, 210, Avenue Felix-Faure, 69003, Lyon, France, connected first by the wire 28 to the micro-contact 17, and second by the wire 29 to the box 15 which controls the feed devices, this contactor being intended to stop the feed devices 8 by acting on the control box 15;
an element with a delaying action 33, for cases of excessive tension lasting for a short period (TPA type supplied by CEM, 210, Avenue Felix-Faure, 69003 Lyon, France, for KOS-8), associated with a contactor which is not represented, the said element with a delaying action being adjusted to control, after a period of time equal to the short limit chosen, for example 3/10ths of a second, the lag between the stopping of the feed devices 8 and that of the knitting machine 9; this element is chosen, nevertheless, so that, after several stoppages (4 or 5) caused by excessive tensions lasting for a short period, a small amount of yarn still remains on the drum of the feed devices 8;
a second element with a delaying action 34, in series with 33, of the same type as the latter, intended to control the final stopping of the machine 9 after a period of time equal to the optimum limit, for example 25 seconds, by acting through the memory 35 on the box 14 which controls the machine; a transistorized memory block 35, of the AMA type, for a contactor of the KOS-8 type supplied by CEM, 210, Avenue Felix-Faure, 69003 Lyon, France, with its contactor which is not represented; and
a third element with a delaying action 36, also connected to a contactor which is not represented, intended to start up the machine, connected firstly to the element with a delaying action 33 and secondly to the box 14 which controls the machine.
The box 14 which controls the machine finally carries a contact 37 which makes it possible to free the memory and which acts on the latter via the conducting wire. In a practical embodiment, this contact 37 can be the control button for starting slow operation.
The device described operates in the following general way:
If excessive tension develops during the unwinding process, the yarn, stretched in the micro-contact breaker 17, causes the controls of the rotating component of the feed device 8 storing the yarn reserve to be stopped (in fact, for practical reasons, the controls of all the feed devices are stopped at the same time). If the excessive tension is overcome by the movement inertia of the rotating component of the feed device within less than 3/10ths of a second, the controls of this component are re-established immediately, and this component immediately re-supplies itself, until the optimum reserve is reached, with a very small amount of yarn unwound from this component, because the machine has not ceased to operate.
If, on the other hand, overcoming the excessive tension during the unwinding of the yarn 1 requires more than 3/10ths of a second, but less than 25 seconds, the following occurs:
During the first period, that is to say up to 3/10ths of a second, the controls of the rotating component of the feed device 8 are stopped, as above. Thereafter, during the second period, that is to say between 3/10ths of a second and 25 seconds, the element with a delaying effect 16 comes into play and causes the controls of the machine to be stopped. Once again, when the excessive tension which has arisen during the unwinding of the yarn 1 has been absorbed by the rotating component of the feed device, the controls are re-established, the moving parts return to their normal speeds, the yarn reserve on the rotating component of the feed device has not been completely depleted because the controls of the machine have been stopped, and the feed device re-supplies itself until the optimum amount is reached.
If, finally, the excessive tension has not been overcome after 25 seconds (or if some other fault has arisen which makes it impossible to normally supply the machine with yarn), the element with a delaying action 34 comes into effect and locks the machine, and the operator has to intervene in order to remedy the failure. After this has been done and after the memory block 14 and the sequential system for effecting gradual starting-up have been employed, the whole returns to normal operation.
The device operates in the following detailed way.
If the tension on the yarn 1 which unwinds and passes through the yarn-guide 24 is normal, the arm 23 is at rest and the knitting machine 9 operates normally.
If, during the unwinding process, the yarn is subject to certain variations in tension -- for example, variation due to starting-up or at the end of forming a coil on the feed device -- the balancing device 23 oscillates from a position A (see FIGS. 4A-4C) to a position B, corresponding to variations in tension which are normal and acceptable during the unwinding process, the position B being such that the rocking movement of the arm 23 driving the cam 27 does not act on the push-button 19 (approach path). In this case also, the push-button 19 is not actuated and the machine 9 continues to rotate.
If excessive tension develops (yarn caught, jumbled yarn, knot or the like), the arm 23 passes beyond the position B and reaches a position C (attack path) such that the cam 27 moves until it operates the push-button 19 and thus engages the micro-contact 17. The indicator 21 lights up and the information is transmitted to the control box with a delaying effect 16. The contactor 32 opens and triggers the stopping of the corresponding feed device 8 by acting on the box 15 which controls the feed device. The machine 9 continues to rotate, taking the yarn stored on the reserve of the drum of the feed device 8. If, during this period, the excessive tension disappears, the contactor 32 closes and this controls the starting-up of the feed devices 8, re-establishes the circuit with 15 and the machine resumes normal operation.
If, on the other hand, the excessive tension persists beyond the limiting threshold fixed for the element with a delaying effect 33, for example 3/10ths of a second, 33 actuates the other element 34 and the contactor (not shown) of memory 35 closes and gives the machine 11 the automatic non-starting order via the cable 31.
If, at this stage, the excessive tension still persists and reaches the maximum threshold fixed, for example 25 seconds, the memory 35 remains held in position and, via 31 and 14, gives the machine 9 the order not to start up automatically. The luminous indicator 21 being lighted and the machine being stopped, the operator can intervene directly at the position in question and can carry out the repair manually. Once this has been effected and the excessive tension has been eliminated, the operator frees the memory by acting on the button 37 and the cycle is returned to zero. The machine starts up at slow speed and then assumes normal speed and automatic operation comes into force. If, however, the excessive tension only lasts for a period of time between the low limit (3/10ths of a second) and the high limit (25 seconds) and frees itself within this period of time, the push member 19 is engaged, which causes the opening of the contactor 32 which then acts on the timing element 33 and the latter in its turn acts on the timing element 36 thus causing the stopping of the machine 11 via the cable 38. If the excess tension disappears before the upper limit (25 seconds) the contactor 32 closes and acts on 33 and 36. The latter in its turn acts to control the automatic placing in operation of the machine 11 via 38 which acts on 14. As a result, this causes the starting of the feed devices 8 by the action of the contactor 32 on the box 15.
If, in exceptional cases, the path of the arm 23 passes beyond the threshold C defined above, the excessive tension which is the cause of this excess is damped by the residual path between the push-button 19 and the profile of the cam 27.
As already stated, the profile of the cam 27, and particularly the profile of the respective proportions corresponding to the approach, attack and residual paths, is calculated as a function, especially, of the values employed for these paths and the nature of the yarns being worked. If the yarn 1 is very fragile, the approach path, and likewise the attack path, will be as low as possible, and the residual path will have the maximum value in order to reduce the inertia effect of the feed device 8 on the yarn. On the other hand, if the yarn 1 is strong (for example, in the case of a polyester yarn texturized by false twist and refixed), the approach, attack and residual paths will have average values.
In an improved embodiment which is not illustrated, a programming device is placed on the direct path 38 between the element with a delaying effect 36 and the box 14 which controls the machine. This programming device is formed from three cams which control respectively the stopping and starting-up again of the machine, and the slow speed and the normal speed of the knitting machine.
With some light or fragile yarns, the inertia of the feed devices 8 is too great relative to the excessive tensions which this yarn could withstand. In order to avoid breaking it and in order to give the machine more flexibility, it is possible either to change the weight of the drum of the feed devices or to equip them with a braking-locking system or no longer to control them individually but in a general way which is independent of the machine, and consequently to make these feed devices work in accordance with the tensions recorded.
The invention possesses numerous advantages relative to the knitting techniques which have hitherto been in general use. All other things being equal, it has been found that, for the same circular knitting machine, the device according to the invention improved the productivity by at least 15%, and even 20% and more, relative to the same machine without a feed device 8, and by at least 5% and preferably 8% and even 10% and more relative to the same machine with feed devices without additional equipment.
It is even to be noted that, according to the invention, the improvement in productivity is the more marked, the poorer the quality of the yarn.
Moreover, in industry, the same operator can be in charge respectively of six standard circular knitting machines without a feed device, eight machines of the same type with a feed device and finally eleven machines equipped according to the invention.
Furthermore, and this point is important, the fatigue of the personnel is considerably reduced since their need to intervene is much less.
Finally, by way of comparison, the same amount of polyester yarn texturized by false twist and refixed from the same defective batch was treated on the same circular knitting machine equipped first with feed devices, and second according to the invention. In the first case, it was found that the operator had to intervene in the case of two hundred and twenty stoppages of the machine. In the second case, it was found that the machine stopped only four times, all the other excessive tensions having caused momentary stoppages, the starting again of the machine having been effected automatically without breaking the yarn.
The invention is particularly suitable for circular knitting machines, but it can be adapted to other textile devices in which it is desired to control the tension of the yarn during treatment. | A process and apparatus for continuously supplying a textile machine, such as a circular knitting machine, with yarn under constant tension, the yarn being stored transiently and continuously in optimum amount on a negative feed drum type storage feeder, wherein when excessive tension arises during feeding lasting for only a short period (for example 3/10ths of a second) the restoring mode of the feed device is stopped whereby the existing supply of yarn on the drum will be fed to the needles. Additionally, when said excessive tension lasts for a period longer than the above short limit but at most equal to a middle limit (for example 3 to 30 seconds) the machine is temporarily stopped. In both cases reactivation of the feed drum so that the yarn can be restored to its optimum amount and restarting of the machine automatically occurs if the excessive tension is eliminated within the above time periods. If however the middle limit is exceeded due to a feed problem which is not self correcting, the machine remains stopped until an operator intervenes to remedy the problem. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to data communication networks and, more particularly, to techniques for providing a packet-aware transport architecture that enhances data volume.
BACKGROUND OF THE INVENTION
[0002] The rapid growth in Internet access and Voice-Over-Internet Protocol (VOIP) services is putting increased pressure on service providers to find cost-effective means of carrying data traffic over their synchronous optical network (SONET) transport networks, originally designed for legacy circuit-switched, time division multiplexed (TDM) traffic. The same is true for service providers with synchronous digital hierarchy (SDH) networks, the predominant standard outside the U.S. It is to be appreciated that while we specifically use the term “SONET” herein, we intend for this to refer to both SONET and SDH networks.
[0003] To address the problem of carrying data traffic over SONETs, two architectures have been proposed. They are the Ethernet-Over-SONET (EOS) architecture and the Packet Ring (PR) architecture.
[0004] A SONET deployment typically consists of Add-Drop Multiplexer (ADM) nodes interconnected as a ring. Such a deployment follows the STS (synchronous transport signal) TDM hierarchy with ring capacities of STS-{12, 48, 192} (622 megabits per second, 2.5 gigabits per second, and 10 gigabits per second of bandwidth capacity, respectively), though next-generation SONET standards such as Virtual Concatenation (VCAT) and the Link Capacity Adjustment Scheme (LCAS) relax this strict hierarchy and allow capacities at the granularity of STS-1.
[0005] Mapping the data traffic from an Ethernet port directly into a SONET pipe leads to inefficient use of bandwidth since data traffic is bursty and the SONET pipe is provisioned at the peak rate. Consequently, in order to make effective use of the bandwidth, SONET ADMs are increasingly including Ethernet line cards (ELC) to perform statistical multiplexing of data traffic before inserting it into the ring. Such transport networks that are adapted to carry data traffic are referred to as packet-aware transports.
[0006] The two models, EOS and PR, differ in how they allocate transport bandwidth for the data traffic. FIGS. 1 ( a ) and 1 ( b ) show the respective schematics. The nodes S 1 -S 5 ( FIG. 1 ( a ) and 1 ( b )) are SONET Add-Drop Multiplexers and A 1 -A 5 ( FIG. 1 ( a )) and P 1 -P 5 ( FIG. 1 ( b )) are the packet processing nodes required in the Packet Ring and EOS models, respectively. Note that this packet processing can be done at the ELC cards mentioned above or in a separate node connected back-to-back to the SONET ADMs.
[0007] In the PR approach, a portion ofthe SONET ring is carved out and dedicated as a “virtual data ring” (VDR) for data traffic (e.g., STS-12 bandwidth from an STS-48 SONET ring). The data packets are processed and switched at every intermediate node along the path to the destination, as shown in FIG. 1 ( a ) for demand D 1 that gets switched at nodes A 2 , A 3 and A 4 . It is to be understood that an intermediate node is a node in the subject path other than the source node and the destination node. The IEEE RPR standard (“IEEE 802.17 RPR,” IEEE Standard, 2004) follows this PR approach.
[0008] On the other hand, in the EOS approach, the data traffic originating at a node is aggregated on the ELC and mapped directly onto a SONET STS pipe of adequate granularity. This pipe is “expressed” through the SONET layer to the destination node with no packet processing at the intermediate nodes. Note that demand D 1 does not get switched at intermediate node P 3 in FIG. 1 ( b ). This approach leads to the creation of a SONET pipe for each node pair that has a demand between them.
[0009] While the EOS approach and the PR approach each provide advantages, they each do not scale effectively to rapid data traffic growth. Thus, a packet-aware transport architecture that enhances data volume by scaling effectively to rapid data growth is desired.
SUMMARY OF THE INVENTION
[0010] The present invention provides a packet-aware transport architecture and techniques for implementing same that enhance data volume by scaling effectively to rapid data growth.
[0011] For example, in one aspect of the invention, a technique for determining a route for a demand in a circuit-switched network comprises the following steps/operations. The demand to be routed in the circuit-switched network is obtained. The circuit-switched network implements a packet ring (PR) model such that one or more demands are routable on one or more virtual data rings in the circuit-switched network. An Ethernet-Over-SONET (EOS) communication channel in the circuit-switched network suitable for accommodating the demand is specified. The EOS communication channel or one of the one or more virtual data rings is then identified as the new route for the demand.
[0012] The demand for which the route is to be determined may be a demand previously rejected by the circuit-switched network, a demand already routed in the circuit-switched network, or a demand anticipated to be routed in the circuit-switched network.
[0013] The step/operation of obtaining the demand may further comprise obtaining at least one of a committed information rate and a peak information rate associated with the demand.
[0014] The step/operation of specifying the EOS communication channel may further comprise computing a bandwidth efficiency metric. Computation of the bandwidth efficiency metric may be based on a size of the EOS communication channel being considered and a measure of the statistically multiplexed bandwidth of demands that the EOS communication channel being considered will accommodate.
[0015] Further, the technique may comprise identifying one or more bottleneck nodes in the circuit-switched network. One or more ofthe identified bottleneck nodes may be bypassed. This may be done by rerouting one or more existing demands in the circuit-switched network.
[0016] Advantageously, illustrative principles of the invention provide service providers with efficient techniques for carrying packet data over their legacy SONET/SDH networks, designed for circuit-switched voice traffic. To this end, illustrative principles of the invention provide a hybrid architecture that makes selective use of EOS communication channels (referred to herein as “pipes”) in conjunction with a PR capability. We formulate and propose a solution to the setup failure re-arrangement problem that dynamically creates EOS pipes to supplement the existing PR if the system fails to satisfy incoming demands. We show through extensive simulations that by doing so, this architecture not only enables higher data traffic loads but achieves it with lower data switching capacity.
[0017] These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 ( a ) illustrates a packet ring network;
[0019] FIG. 1 ( b ) illustrates an Ethernet-Over-SONET network;
[0020] FIG. 2 illustrates a packet ring model;
[0021] FIG. 3 illustrates an Ethernet-Over-SONET model;
[0022] FIG. 4 illustrates a hybrid ring model, according to an embodiment of the present invention;
[0023] FIGS. 5 ( a ) through 5 ( d ) illustrate hybrid ring solutions, according to embodiments of the present invention;
[0024] FIG. 6 illustrates a set-up failure re-arrangement algorithm, according to an embodiment of the present invention;
[0025] FIG. 7 illustrates a set-up failure re-arrangement algorithm, according to another embodiment of the present invention;
[0026] FIGS. 8 through 12 illustrate simulation results, according to embodiments of the present invention; and
[0027] FIG. 13 illustrates a computing system suitable for implementing one or more setup failure re-arrangement methodologies, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Principles of the invention will be illustrated herein in conjunction with the EOS and PR models for SONET (SDH) networks. It should be understood, however, that the invention is not limited to use with such models and networks, but is instead more generally applicable to any packet-aware transport environment in which it is desirable to more effectively provide for data volume growth.
[0029] It is to be appreciated that, as used herein, the term “pipe” generally refers to a communication channel, e.g., a SONET pipe is a communication channel in a SONET network used to transmit data or voice.
[0030] Principles of the present invention realize that the EOS and PR approaches each have their benefits and disadvantages. Thus, illustrative embodiments described herein are directed toward the PR model and how one may improve it in an environment that observes rapid data growth and consequently, significant traffic chum. In one embodiment, a new architecture (referred to herein as a hybrid ring architecture) is provided that makes selective use of EOS pipes in conjunction with the PR model to create a network that scales gracefully to rapid growth in data traffic.
[0031] The remainder of the detailed description is divided into the following sections for convenience of reference. In section I, we motivate the hybrid ring architecture. Then, in section II, we formulate the setup failure re-arrangement problem (SFR), that is used to design the hybrid ring, and highlight the various subproblems that need to be solved to address this problem. We provide an algorithm for SFR in section III and then present simulation experiments and results in section IV. Section V explains certain hardware and management considerations, while section VI describes an illustrative computing system for use in implementing the methodologies described herein.
[0000] I. Hybrid Data-Ring Architecture
[0032] In this section, we provide a high-level motivation for the hybrid ring architecture. First, we make a few pertinent observations about the PR model:
[0033] The PR model requires the links in the VDR to be the same size on all hops of the ring. This is to ensure sufficient bandwidth exists to automatically reroute the traffic during failure. However, this also implies that the most loaded hop determines the size of the VDR.
[0034] The ELC on a node is used to switch two types of packets—traffic that adds/drops at the node and traffic that is “pass-through,” i.e., destined for another node further along the ring.
[0035] The data switching capacity of the ELC on commercially available PRs is usually lower than the total optical capacity of the ring. Thus, new data service requests may be refused if the VDR has no spare capacity even though bandwidth exists in the remainder of the SONET ring.
[0036] Given these observations, we use the following example to highlight the drawbacks of scaling the PR model to increasing volumes of data traffic. Consider the design of a five-node STS-12 size ring with each node having an ELC with switching capacity of 300 Mbps (corresponding to STS-6 worth of switching capacity).
[0037] In the EOS model, the required switching capacity at each node is computed as the sum of the capacities of all data “links” emanating on that node. In the PR model, it is twice the size of the VDR (sum of the east-side and west-side capacity, that can be dropped at the node). For example, switching capacity of 300 Mbps translates to an STS-3 VDR. Let the nodes be numbered A-E and consider the need to support five demands on the data topology between different node pairs—demand D 1 of 60 Mb between A and C, D 2 of 80 Mb and D 3 of 10 Mb between D and A, D 4 of 100 Mb between E and D and D 5 of 60 Mb between C and D.
[0038] FIGS. 2 and 3 show how these demands would be routed in the data network following the PR and EOS models, respectively. Now assume that there is a new demand D 6 for 40 Mb between nodes B and D. As the two figures show, it would be rejected under both the models.
[0039] Consider the PR case ( FIG. 2 ). Since each pass-through demand uses twice the switching capacity, once on the east-side link and once on the west-side link, 280 Mb of switching capacity is used up at node B to support the two pass-through demands D 1 and D 2 . This leaves only 20 Mb spare capacity which is not enough to add/drop this new demand. Therefore, unless the size of the VDR and hence the switching capacity is increased, it is not possible to satisfy all demands. Nodes like B, that are congested due to pass-through demands, are referred to as “bottleneck” nodes. The data switching capacity which could have been more advantageously used to support demands that add-drop at these nodes, is being used by pass-through demands. The important point to note is that even though we are using shortest path routing to route demands on the VDR, this problem of inefficient utilization of switching resources arises even with complex ring loading schemes that balance the load on the ring.
[0040] The EOS case ( FIG. 3 ) rejects this new demand for a different reason. Since EOS pipes are dedicated to each pair of nodes between which there is a demand, each of the five existing demands map to a pipe of the closest STS granularity. All EOS pipes, shown in dark bold lines in the figure, are of size STS-1-2v and the dotted lines denote the demands that each EOS carries. Demands between the same pair of nodes, like D 2 and D 3 , can be multiplexed on the same EOS pipe. Creating these EOS pipes results in dividing up the switching capacity at the nodes and may reduce the overall efficiency of the network. For example, the 60 Mb demand between nodes C-D is carried over an STS-1-2v pipe (100 Mb), at only 60% bandwidth efficiency. The 300 Mb switching capacity at node D is used up by the EOSs created to carry the four services originating at the node. Consequently, even though the destination node (B) has spare capacity, demand D 6 , which requires the creation of a new STS-1 EOS pipe between B and D, is rejected due to lack of switching resources at D. Only by increasing the switching capacity at node D, can this new demand be met.
[0041] This simple example highlights the tradeoffs between the PR and EOS approaches. In EOS, the switching capacity of a node is utilized only at the source and destination node for any demand. However, the efficiency may be lower since fewer demands can be stat-muxed (statistical time division multiplexed) onto an EOS pipe. On the other hand, a node may exhaust its switching capacity, routing “pass-through” traffic in the PR model, thereby disallowing new requests even though there may be available capacity overall.
[0042] Principles of the invention therefore provide a hybrid ring architecture that uses EOS pipes in conjunction with the PR model to achieve an improved architecture. FIG. 4 shows how use of a hybrid ring model according to the invention advantageously allows for all the demands from the last example to be met. A VDR of size STS-1-2v in conjunction with an EOS pipe of size STS-1-2v between nodes D and A to carry demands D 1 and D 2 still needs 300 Mb of switching at nodes A and D but only 100 Mb switching at nodes B, C and E. This VDR has enough free capacity to carry demand D 6 . Thus, the hybrid ring architecture can support more data traffic for lesser switching capacity than either PR or EOS architectures.
[0043] Thus, one key algorithmic challenge for the hybrid ring architecture is the hybrid network layout problem, namely, how do you determine the number and size of the EOS pipes and the appropriate size of the VDR. From an algorithmic viewpoint, there are a number of ways to address this problem. One approach would be to formulate a network design problem—given a set of demands, what are the optimal set of EOS pipes and the VDR size that can support the demands. However, while a design approach is appropriate for a green-field environment, we seek a solution that could operate at run-time on a network that carries live, operational traffic. Moving an operational network from one design to another is a hard problem and can be reduced from the between-ness problem Therefore, principles of the invention perform hybrid network reconfiguration (HNR) that supplements the existing network with new EOSs and leads to a gradual growth of the virtual data network. A goal is to then be able to provision more demands on the EOS pipes just created or, along the VDR. HNR is the focus of the remainder of the detailed description.
[0000] II. Hybrid Network Re-Configuration Problem
[0044] In this section, we outline the specific theoretical problem we seek to solve and highlight some of the key sub-problems that have to be addressed for an effective solution to the HNR problem.
[0045] As shown in the example above, new data requests cannot be provisioned on the VDR, because one or more nodes no longer have sufficient spare data switching capacity. Therefore, to solve the HNR problem, principles of the invention provide for creating one or more EOS pipes to bypass such “bottleneck nodes.” Rerouting pass-through demands from these nodes to the new EOSs, frees up switching capacity that can now be used to support add-drop data traffic. This re-configuration can be performed in a pro-active manner in anticipation of future requests, or it can be a reaction to a pre-defined trigger such as failure to provision new data demands. Since performing pro-active reconfiguration is a straightforward extension of the trigger-based reconfiguration, the description below focuses on the latter.
[0046] Formally, we aim to solve the setup failure re-arrangement (SFR) problem. Since a requirement in our illustrative case is to perform the re-configuration in the presence of live traffic, we seek to minimize any impact on the flowing traffic.
[0047] The SFR problem is as follows:
[0048] SFR Definition: Given the failure to setup a new demand in a VDR ring, derive a set of one or more EOS pipes such that:
[0049] a) provisioning of these EOS pipes enables this new demand to be met
[0050] b) given a choice of EOS pipes, create the ones with the highest bandwidth efficiency metric(BEM).
[0051] BEM captures the cost-benefit ratio of creating an EOS and determines the efficiency of an EOS in utilizing network resources. It is used as the primary metric to select the set of EOS pipes to be created.
[0052] Clearly, we are addressing the HNR problem using a localized heuristic reconfiguration. However, we do so because we are looking for an effective, practical solution that causes minimum disruption and not a wholesale network wide redesign, and indeed the simulation results below justify the efficacy of the approach.
[0053] The SFR problem translates into solving two distinct sub-problems, namely, the bottleneck selection problem and the EOS selection problem, and we highlight both of these problems below.
[0054] Nodes that carry pass-through traffic are potential candidates for bottleneck selection as rerouting such traffic can relieve the congestion on the node. Identification of these bottleneck nodes is straightforward if a specific demand fails to setup—all nodes without sufficient capacity on the selected path for this new demand qualify as bottlenecks. However, if this optimization is done in a pro-active manner as mentioned above, the choice of which nodes will become bottlenecks may be less obvious. Some possible candidates are nodes that use up more than x% of there switching capacity for pass-through traffic. In any case, for this discussion of the SFR problem, we will assume that the bottleneck nodes are given as input to the reconfiguration. The objective of the SFR problem is to relieve the bottlenecks by rerouting the pass-through traffic to bypass these nodes. Further we assume that appropriate graph transformation (see, e.g., J. L. Gross and T. W. Tucker, “Topological Graph Theory,” Book News, Inc., 2001) can be applied to the network in such a way that the problem can be converted to relieving bottleneck links.
[0055] Given a set of bottleneck links, there are multiple ways that new EOS pipes can be created, to bypass the bottleneck links, all of which will achieve the target—a tradeoff is to determine the comparative value of additional resources the EOS will use and the amount of data switching capacity it frees up on the nodes.
[0056] Consider FIG. 5 ( a ). There are five existing demands on a VDR of size STS-1-3v. Demands D 1 and D 4 between nodes B and D are both of size 40 Mb. Demand D 2 between nodes B and C is of size 70 Mb, D 3 between E and C of size 20 Mb and D 5 between C and D of size 150 Mb. Now there is a new request for a 60 Mb demand between A and C which cannot be satisfied on the existing VDR as node A is bottle-necked due to pass-through demands. FIGS. 5 ( a ), 5 ( b ) and 5 ( c ) show the three potential EOS pipes that can be created to clear the bottleneck at node A and we use these to highlight the various factors that influence EOS selection.
[0057] BEM: The benefit of an EOS pipe can be measured by the amount of switching capacity it saves on the bottleneck links. The cost can be computed based on the amount of underlying SONET bandwidth it uses to realize this EOS and the switching bandwidth that is wasted due to the creation of this dedicated pipe. Since in most networks of today, optical capacity is underutilized and data traffic is growing, the cost of using the optical resources is not a primary concern and wasted capacity primarily drives the cost of the EOS.
[0058] Consider the potential EOS pipes in FIG. 5 ( b ) and FIG. 5 ( c ). An EOS (E 1 ) of size STS-1-1v (51 Mb) between C and E, as shown in FIG. 5 ( b ), that carries demand D 3 wastes 31 Mb bandwidth and needs a peak switching capacity equivalent to STS-7 at C and E and STS-6 at all other nodes. On the other hand, an STS-1-2v (102 Mb) EOS (E 2 ) between B and D, as shown in FIG. 5 ( c ), that carries demands D 1 and D 4 wastes only 22 Mb of EOS space but needs a peak switching capacity equivalent to STS-8 at B and D and STS-6 at all other nodes.
[0059] Thus creating E 2 is definitely more efficient from the point of view of wasted bandwidth. But E 1 is closer in size to the failed demand and needs only an additional STS-1 switching capacity at both the end-nodes as compared to E 2 that needs additional STS-2 switching capacity. Thus, creating E 1 may be more beneficial in the short-term even though E 2 is more efficient. In fact, no matter how efficiently one may pack an EOS, creating one that is disproportionately large limits how much the virtual data network can grow (since the switching capacity of an ELC is fixed). Consequently, when creating new EOS pipes, these two independent factors need to be balanced and the BEM metric below aims to do so:
BEM= ( MB−LS ) −k*LS/DB
[0060] where,
[0061] LS is the size of the EOS pipe (in Mb) being considered,
[0062] MB is the statistically multiplexed bandwidth of all demands that the EOS will carry and
[0063] DB is Requested bandwidth of the failed setup demand
[0064] MB−LS is a measure of bandwidth that is wasted on the link and clearly this waste is minimum if the complete link can be filled up with multiplexed demands. LS/DB determines the relative size of the EOS link as compared to the size of the failed demand. The factor k determines the relative weight of these two components on the efficiency of the EOS pipe.
[0065] Alternatively, the efficiency of wasted bandwidth can also be computed based on the number of nodes on the VDR that the EOS bypasses. For example, an EOS that saves switching capacity on 5 nodes may be preferable to one which saves capacity on 2 nodes even though it may waste slightly more bandwidth. If optical capacity is of concern it may also have to be considered while defining the BEM. Even though various such factors can be combined to form a different heuristic for BEM that selects the set of EOS with which to supplement the hybrid ring, the efficacy of the BEM formulation defined above, can be seen from the simulations below.
[0066] EOS Routing Model: The management overhead required to route the demands in the hybrid ring is another factor that determines if a particular EOS design is feasible. In FIG. 5 ( c ), the STS-1-2v EOS carries demands D 1 and D 4 between nodes B and D and frees up 80 Mb of VDR space at both nodes E and A. In this design, only demands between the end-points of EOS are routed on the EOS, the other demands are routed on the VDR. We call this routing model “direct routing” (DR).
[0067] An alternative way to design an EOS is shown in FIG. 5 ( d ). The STS-1-2v EOS between B and E bypasses node A and can be used to carry any demands that are passing through node A. The demands are then dropped at B and E and then added back to the VDR to be carried the rest of the way to their final destination. For example, D 1 and D 4 are carried on the EOS from B to E and then dropped at E to be carried on the VDR to be finally dropped at D. Similarly D 3 is also routed for part of its route on the EOS and for the other part on the VDR. This routing model is called “indirect routing” (IDR). Note that the peak switching capacity required in this example is STS-8 at nodes B and E, which is the same as the switching required in FIG. 5 ( c ) at nodes B and D though the EOS in this case is much better utilized as it is completely full. Thus, this methodology can lead to better efficiency by allowing any demand to be multiplexed on the EOS but may require a more sophisticated routing and management scheme. Several factors that influence the decision of what routing model to use in hybrid ring are further discussed below. Even though, in this illustrative explanation, we focus on the DR model that allows demands to use either EOS or VDR but not both, it is to be understood that using other routing models would also provide the advantages of the hybrid ring model.
[0068] Statistical Multiplexing Scheme: In case of bursty data traffic, the bandwidth requirements are defined by a committed information rate (CIR) and a peak information rate (PIR) and the difference between the PIR and CIR is called excess information rate (EIR). For a non-bursty demand, CIR is same as PIR. The statistical multiplexing schemes used to aggregate data streams determine the minimum required bandwidth or the multiplexed bandwidth (MB) on the shared resource, be it PR or EOS.
[0069] Consider a simple multiplexing scheme:
MB=ΣCIR i +OF/ 100*Σ EIR i
where OF is the over-provisioning that is required to support the PIR. Note that making the OF 100% would mean that the PIR of all the demands have to be supported simultaneously whereas OF=0 means that only the CIR has to be supported. The service provider may set this OF between 0 and 100 based on the service guarantees that have to be provided.
[0070] Consider an example with three bursty demands that need to be multiplexed on a single shared link. Let these demands have the following (CIR, PIR) bandwidth requirements: D 1 with (20 Mb, 50 Mb), D 2 with (20 Mb, 200 Mb) and D 3 with (30 Mb, 50 Mb). The CIR sum on the link is 70 and the sum of excess information rate (EIR) is (50−20)+(200−20)+(50−30)=230 Mb. With OF of 50%, MB=185 Mb and therefore requires the size of the link to be at least STS-1-4v (204 Mb) whereas with OF=33%, MB=147 Mb, and hence an STS-1-3v link should be enough to support all the demands. But D 2 has a PIR of 200 Mb and to support this PIR, the link size has to be at least STS-1-4v (204 Mb). Therefore, the required bandwidth on the link can be computed as max (MB, max (PIR i )). Since the link granularity is STS-1 (51 Mb), the link size (LS in STS) is computed as:
LS =ceil (max ( MB , max ( PIR i ))/51).
[0071] There are many other schemes to compute the MB and one of them is based on the number of data streams being multiplexed on the link. For the illustrative embodiment here, we use the simple multiplexing scheme formulated above to determine if the VDR has enough bandwidth to accommodate a new demand and also to determine the required size of an EOS pipe. The MB computed using this formulation is then used to determine the EOS efficiency as described above in this section.
[0072] Candidate Demand Set Selection: Once the bottleneck links are selected, a set of demands that can be rerouted has to be chosen. The choice of these demands depends on the service level agreements (SLAs) or the properties of the demand. For example, demands whose SLAs penalize even temporary service degradation should never be rerouted. The demand properties also determine if it is best routed on VDR or an EOS. For example, a private line demand should be routed on an EOS if the SLA does not allow multiplexing with other demands whereas a multicast or broadcast demand is a good candidate for routing on VDR as it requires less resources. These and other criterion should be used to determine a candidate set of demands that can be rerouted without affecting the service quality.
[0000] III. SFRA Algorithm
[0073] In this section, we present the SF'RA algorithm for reconfiguring the virtual data network when a new request for data service is rejected. The SFRA algorithm is shown in FIG. 6 . In this illustrative algorithm, any time a new EOS is created, the switching capacity required by the EOS is added to the end-nodes switching capacity, provided it does not exceed the maximum limit for this node. The freed up switching on the nodes in the packet ring can then be used by other demands.
[0074] As indicated in FIG. 6 , the input to the algorithm is: (i) the rejected demand d between source-destination pair (o, t) and its CIR d , PIR d requirement; and (ii) the bottleneck links BL. The output is: (i) the new route for the rejected demand; or (ii) a failure indication (i.e., no new route is available for the rejected demand).
[0075] Step 1 of the algorithm is to create a list of demands that use any links in set BL. Step 2 is to sort these demands in sets P s,d based on the src-dest pair s,d of the demands and add the rejected demand in the set P o,t . Step 3 is to call function designEOS( ) for each set to compute the potential EOS with its size and efficiency. Step 4 is to select the EOS which has the most efficiency. In step 5, if no EOS could be found, the algorithm goes to step 9. If an EOS is found, but there is a scarcity of optical resources or switching capacity at EOS end-nodes, then step 6 directs to skip that EOS and return to step 4. If there is no such scarcities, then step 7 directs to allocate optical resources to this EOS between s, d and reroute the demands in the set P s,d . Step 8 directs that if BL still do not have enough spare capacity for d, then return to step 4. Step 9 directs that if BL is still not free, then return a failure indication, else return success in step 10.
[0076] It is to be appreciated that the function designEOS called in step 3 computes MB, LS and BEM as defined in FIG. 6 .
[0077] By way of example, consider FIG. 5 and assume that the underlying SONET ring is STS-12 and switching capacity can be increased to the maximum capacity. Since the new demand between node A and C is rejected, this demand and its bandwidth requirements are fed to the algorithm. Also, node A being the bottleneck node, link A-B on the shortest route A-B-C is fed to the algorithm as the bottleneck link. Using step 1 and 2, the algorithm creates two sets—P E,C ={D 3 }, P B,D ={D 1 , D 4 }. The function designEOS is used to compute two potential EOSs, E 1 between E and C with MB= 20 and LS=1 and E 2 between B and D with MB=80 and LS=2. For E 1 . BEM=(20−51)−51/20=−33.5 and E 2 's BEM=(80−102)−102/20=−27.1. Step 4 selects E 2 as it is most efficient, and since there is enough optical bandwidth and switching capacity, the algorithm allocates resources for this EOS in step 7 and reroute D 1 and D 4 . Step 8 determines that enough capacity has been freed at bottleneck link A-B and the algorithm returns success and D 6 can now be routed on the VDR.
[0000] IV. Simulations
[0078] In this section, we illustrate the efficiency of the hybrid ring of the invention as compared to a PR network, as the data traffic in the network grows. We start by describing the simulation model that is used for the network and then present some results on the performance of the SFRA algorithm.
[0000] A. Simulation Model
[0079] We use a testbed of an OC-192 SONET ring with eight nodes that is used to create the appropriate virtual data network. In addition, the maximum switching size in the network is specified and it limits the amount of data traffic that can be provisioned in the network. As explained above, the PR model carries all its data traffic on a VDR and the hybrid ring model carries data traffic on a combination of VDR and EOS pipes.
[0080] A goal of the experiments is to satisfy as many incoming data demands as possible. In both PR and hybrid ring models, we start with a VDR of size STS-1-48v and grow the virtual data topology until the SONET ring capacity is exhausted or the maximum switching capacity is reached.
[0081] In the PR model, on setup failure, a packet ring algorithm (PRA) grows the VDR by the minimum bandwidth required to satisfy the rejected demand. For example, consider a VDR of size STS-1-3v that is completely full. To satisfy a new demand of size 40 Mb between any two nodes, increasing the VDR size to STS-1-4v is sufficient. The VDR can grow until there are available resources in the optical domain and the maximum switching capacity is reached.
[0082] In the hybrid ring model, on setup failure, an SFR algorithm is called, that creates or modifies a set of EOSs in order to satisfy the new request. For our simulation, we are using the DR routing model where demands are not allowed to straddle both EOS and VDR.
[0083] To study the performance of the SFRA algorithm, we compare it to a simple SFR algorithm called SFEA presented in FIG. 7 . The SFEA and SFRA algorithms differ in the way they decide which EOS to provision in the network. In SFEA, EOS creation is straightforward as opposed to the SFRA where efficient EOS design is a key. In SFEA, either an existing EOS pipe is enlarged (step 1) or a new EOS pipe is created (step 2) between the end nodes of the rejected demand. Whereas in SFRA, EOS pipes are created or modified to bypass bottleneck nodes, in order to satisfy the rejected demand. It may lead to rerouting of some existing demands in the network as explained above. Lastly, in SFEA, if enough available optical and switching resources are available, resources are allocated (step 3) to the EOS and the algorithm returns the EOS as a feasible route for d, else a failure is returned (step 4).
[0084] To simulate data growth, new requests for data demands are made between randomly selected pairs of nodes. In the graphs presented in FIGS. 8 through 12 , the number of demands that were requested until any point of time are represented by NRD. The bandwidth of the data demands is defined in terms of (CIR, PIR) values. For bursty demands, the PIR is randomly selected to be either 10 MB, 100 MB or 1000 MB/1 GB, to correspond with Ethernet rates and the CIR is a randomly generated number between 0 and PIR. A 1000 MB PIR demand is generated less frequently than smaller demands to mimic the nature of real traffic in the network.
[0000] B. Illustrative Performance Results
[0085] In this section, we compare the performance of PR and the two algorithms for hybrid ring, SFRA and SFEA. The primary performance metric is the provisioned data volume (PDV) that indicates the amount of data traffic that could be actually provisioned on the virtual data network. This PDV can directly be translated into revenue generated by this data network. In case of bursty demands, the (PDV) is the multiplexed bandwidth of all the demands provisioned in the network and this bandwidth is computed using the multiplexing scheme defined above in section II. Another performance metric is the required peak switching capacity (PSC) required at the maximally loaded data node. The amount of underlying optical bandwidth (UOB) that is used to create the virtual data network is another metric that determines the performance of the algorithms. We compute this UOB as the sum of bandwidth used on each link in the SONET ring by the virtual data network. For example, an 8 node STS-3 VDR will use 8×3 =24STS optical capacity.
[0086] In order to limit the run time of the algorithms, we stop the experiment if we cannot satisfy 20 consecutive incoming data demands, as it means that the network is very saturated.
[0087] The switching capacity at each node in the following simulations is limited to STS-192. This means that in the PR model, the VDR can grow up to a maximum of STS-1-96v.
[0088] 1) Simulation 1: Total Provisioned Data Volume: Consider FIG. 8 . It compares the PDV for the PR, SFEA and SFRA. As expected, the PDV increases as new requests for data demands enter the system and are provisioned, but at some point, the algorithms start rejecting demands due to lack of resources. Note that the three algorithms may reject different demands as they have a different virtual data topology. The difference in PDV value at any given NRD captures the relative rejection rates of the three algorithms. As can be seen from the comparison of the PDV for NRD values between 100 and 200, the PRA starts rejecting demands much earlier than either the SFRA or the SFEA algorithm. In addition, the PRA supports substantially less data volume in the end, than either of the hybrid ring algorithms.
[0089] A comparison of the SFRA and SFEA performance shows that SFEA starts rejecting demands earlier than SFRA and supports almost 18% less data volume. This shows that intelligent design of EOS, as provided by SFRA, can add substantially to the advantages of using a hybrid ring. As seen from FIG. 8 , SFRA supports almost 70 percent more data volume which can be directly translated into an increase in service provider revenue. Moreover, as the next few experiments demonstrate, this increased data volume is supported with lesser switching requirements and minimal increase in the usage of underlying optical capacity.
[0090] 2) Simulation 2: Comparison of Peak Switching Capacity: FIG. 9 compares the required switching capacity ofthe most loaded node. All three algorithms mentioned above start with the peak switching capacity of STS-96 as required by the VDR of STS-48. Once the current switching capacity cannot satisfy incoming demands, all three start requiring more switching capacity. As the figure shows, the SFRA supports more PDV for the same switching capacity than either the PRA or the SFEA.
[0091] Another way to look at this graph is to consider the peak switching capacity required to support a given amount of data volume. As expected, the peak switching capacity required by SFRA is less than that required by the PRA as it tries to avoid using switching capacity for pass-through traffic. An interesting result is the superior performance of SFRA as compared to SFEA as SFEA always creates direct EOS pipes for all new demands once the VDR is full and would have been expected to use lesser switching capacity. This shows the efficiency of the SFRA in creating EOS pipes as compared to the more simplistic EOS creation as in SFEA. Note that since PRA requires all nodes in the ring to have the same switching capacity and nodes in the hybrid ring can have different switching capacities, the cost of the entire virtual data network is substantially more in PRA than in SFEA.
[0092] 3) Simulation 3: Optical Bandwidth usage as measure of cost: In addition to the cost of the required switching capacity, the cost of creating a virtual data network network is also measured by the amount of the underlying optical bandwidth used to create the virtual data network. FIG. 10 plots this increasing optical bandwidth usage for each of the three algorithms as the network grows, starting from the identical VDR with UOB as 8×48=384 STS. As expected, the SFRA needs optical bandwidth as it creates multiple point-to-point EOS pipes as compared to the PRA which creates a single shared VDR. The point to note is that this difference is quite small until the PRA has reached the maximum switching capacity and can grow no more, thereby rejecting most requests. Since the SFRA is still accepting most demands that enter into the system at this point as seen in FIG. 8 , we stop the comparison at this point. Even though SFRA supports less data volume than the SFEA at some points, the UOB for both grows hand-in-hand and, at the end, SFRA supports more data traffic. Since, in todays networks, the optical bandwidth is underutilized and the data demands are growing, this little increase in the usage of optical bandwidth by the SFRA is more than offset by the increased volume of data traffic that can be provisioned in the network using lesser switching capacity.
[0093] The above simulations were based on the assumption that most optical networks, supporting data traffic, will have lower switching capacity than optical capacity, as mentioned above. But the advantages of the hybrid ring hold even when this assumption does not hold and the data switching capacity on a node is the same as the optical capacity. The following few examples demonstrate this in an OC-192 SONET ring network where the data switching capacity at each node equivalent to STS-384 which means that the VDR can grow up to STS-192.
[0094] 4) Simulation 4: Total Provisioned Data Volume: FIG. 11 shows that the SDT increases as new requests for data demands enter the system and at some point a few demands start getting rejected. Until about 500 demands, the data volume supported by the Packet Ring and SFRA is almost the same, but between 500 and 600 demands the virtual data network in PRA gets saturated and cannot support more data whereas the SFRA keeps accepting more demands and ends up supporting almost 15 percent more data volume. SFEA, on the other hand, starts rejecting demands earlier than both the PRA and SFEA and supports lesser data volume than both until the PRA stops. At the end, SFEA supports some more data volume than the PRA but since this increase is achieved at the cost of early rejections it may not be a lucrative solution. The SFRA consistently outperforms SFEA and supports almost 8 percent more data volume than SFEA. This shows that creating EOS pipes efficiently in the hybrid ring is crucial to the success of the hybrid ring and that SFRA does this job very well.
[0095] 5) Simulation 5: Peak Switching Capacity: In FIG. 12 , SFRA supports more PDV for the same switching capacity than PRA going up to 45 percent or more after PSC after 250 STS. Looking at the flip side of this graph, SFRA requires almost 30 percent less switching capacity than PRA for supporting the sane volume of data traffic. As expected, SFEA starts with supporting more data traffic for the same switching capacity, but it also rejects more data demands as seen from FIG. 11 . After PSC value 250 STS, the performance of SFRA catches up with SFEA and ends up supporting more data volume. Note that SFEA and SFRA do not reach the maximum switching capacity as they exhaust underlying optical capacity earlier. This behavior is consistent with the result in FIG. 10 .
[0096] These simulations prove that SFRA is a good algorithm for creating a hybrid ring that can support substantially more data volume than PR and is efficient in its use of both data switching and optical resources.
[0000] V. Hardware and Management Considerations
[0097] This section discusses some ofthe challenges that have to be addressed for implementing the Hybrid Ring model.
[0000] A. Hardware
[0098] 1) Data Switching: In packet-aware transport networks, a set of SONET channels is configured to carry data traffic and these channels are dropped, the data processed and the channels added back at the SONET ADMs. The data processing can happen either at an external node or at line cards on the SONET ADM. The key difference in PR and the hybrid ring model arises in the kind of processing required at this data processing node or line card. In PR, the data switching is restricted to a drop or forward decision, but in the hybrid ring model, full switching is required between the different EOSs and the VDR. So, each node in the hybrid ring employs a packet switch instead of a packet ADM with support for a routing table that can be configured based on the EOSs in the hybrid ring.
[0099] 2) Hitless Rerouting: Relieving bottlenecks in the hybrid ring includes rerouting some demands and moving them from the VDR to EOS, and vice versa. Such a movement should not degrade the quality of that service. Any rerouting which satisfies the QoS (quality-of-service) guarantees of a service is called “hitless.” All nodes should have the capability to provide hitless rerouting for the hybrid ring.
[0000] B. Network Management
[0100] 1) Fairness: Another difference between the hybrid ring and PR model is in the traffic shaping and fairness algorithms. In the DR model explained divided between the VDR and EOS, separate fairness algorithms can be used for the two. For the VDR portion, back flow schemes such as those proposed in the RPR literature (“IEEE 802.17 RPR,” IEEE Standard, 2004) can be used. Since an EOS carries traffic only between a single pair of nodes, traffic shaping can provide adequate fairness amongst the streams being multiplexed on an EOS. On the other hand, in the IDR scheme, where the data demand can hop from the VDR to the EOS and vice versa, since the fairness schemes based on back-flow will not work as the topology is now a mesh, a simple and efficient fairness algorithm for the IDR routing scheme for hybrid ring may be employed.
[0101] 2) Protection: Both the EOS and VDR portion of the hybrid ring can have independent protection schemes in the DR scheme as they carry different data streams. The protection scheme for VDR is similar to ones for other PR schemes such as RPR (“IEEE 802.17 RPR,” IEEE Standard, 2004). The protection scheme for EOS is based on the SONET protection scheme such as UPSR (Unidirectional Path Switched Ring) or BLSR (Bidirectional Line Switched Ring). We can improve on the BLSR scheme by only protecting the EOSs that carry demands with protection requirements. The rest of the demands can be put on the EOSs that are allocated resources from the unprotected pool. In the IDR scheme, restoration for demands that straddle both VDR and EOS may be done piecemeal, on the different segments of the route, through the node where it switches between. VDR and EOS is a single point of failure.
[0102] 3) Network Optimization: The HNR problem described herein has focused on augmenting the VDR with appropriate EOSs in order to adapt the network to growing number of data demands. In an operational network, demands are added and deleted over time and the traffic pattern keeps changing. For example, there may be more demands between nodes A and B at some time and between B and C at other times. This means that the hybrid ring needs to keep evolving over time and this boils down to an optimization of virtual data network including resizing the VDR and adding, deleting and resizing of EOS pipes.
[0103] We have shown how to efficiently create new EOS based on traffic demands. Similar heuristics as BEM defined in section II can be used to determine when the EOS is too inefficient to be feasible. For example, any EOS where the multiplexed bandwidth is a small percentage of the EOS bandwidth is too underutilized to be efficient. This information can then be used to either down-size the EOS or to reroute the demands on the EOS onto the VDR or other EOSs and then release this EOS. The resources released by this EOS can be utilized by an EOS between other nodes that are more in demand. Over time, this selective reconfiguration will lead to a data topology that is more completely in tune with the changing traffic pattern than the PR model.
[0000] VI. Illustrative Computing System
[0104] Referring now to FIG. 13 , a block diagram illustrates a generalized hardware architecture of a computer system suitable for implementing a system for performing the setup failure re-arrangement methodologies (e.g., the SFRA algorithm of FIG. 6 , the SFEA algorithm of FIG. 7), according to an embodiment of the present invention. More particularly, it is to be appreciated that computer system 1300 in FIG. 13 may be used to implement and perform the methodologies of the invention, as illustratively described above in the context of FIGS. 1 through FIG. 12 . Also, it is to be understood that one or more network elements (e.g., ADMs, packet processing nodes, routers, etc.) may implement such a computing system 1300 . Of course, it is to be understood that the invention is not limited to any particular computing system implementation.
[0105] Thus, computing system 1300 could be used to determine a new route for a rejected demand and a hybrid ring architecture for implementing same, in accordance with the methodologies of the invention described herein, such that the route and architecture could then be implemented online on the subject network by a service provider.
[0106] In this illustrative implementation, a processor 1302 for implementing at least a portion of the methodologies of the invention is operatively coupled to a memory 1304 , input/output (I/O) device(s) 1306 and a network interface 1308 via a bus 1310 , or an alternative connection arrangement. It is to be appreciated that the term “processor” as used herein is intended to include any processing device, such as, for example, one that includes a central processing unit (CPU) and/or other processing circuitry (e.g., digital signal processor (DSP), microprocessor, etc.). Additionally, it is to be understood that the term “processor” may refer to more than one processing device, and that various elements associated with a processing device may be shared by other processing devices.
[0107] The term “memory” as used herein is intended to include memory and other computer-readable media associated with a processor or CPU, such as, for example, random access memory (RAM), read only memory (ROM), fixed storage media (e.g., hard drive), removable storage media (e.g., diskette), flash memory, etc.
[0108] In addition, the phrase “I/O devices” as used herein is intended to include one or more input devices (e.g., keyboard, mouse, etc.) for inputting data to the processing unit, as well as one or more output devices (e.g., CRT display, etc.) for providing results associated with the processing unit. It is to be appreciated that such input devices may be one mechanism for a user to provide the inputs used by a system of the invention to generate results. Alternatively, the inputs could be read into the system from a diskette or from some other source (e.g., another computer system) connected to the computer bus 1310 . Also, inputs to the methodologies may be obtained in accordance with the one or more input devices. The output devices may be one mechanism for a user or other computer system to be presented with results of the methodologies of the invention.
[0109] Still further, the phrase “network interface” as used herein is intended to include, for example, one or more devices capable of allowing the computing system 1300 to communicate with other computing systems. Thus, the network interface may comprise a transceiver configured to communicate with a transceiver of another computer system via a suitable communications protocol. It is to be understood that the invention is not limited to any particular communications protocol.
[0110] It is to be appreciated that while the present invention has been described herein in the context of networks, the methodologies of the present invention may be capable of being distributed in the form of computer readable media, and that the present invention may be implemented, and its advantages realized, regardless of the particular type of signal-bearing media actually used for distribution. The term “computer readable media” as used herein is intended to include recordable-type media, such as, for example, a floppy disk, a hard disk drive, RAM, compact disk (CD) ROM, etc., and transmission-type media, such as digital or analog communication links, wired or wireless communication links using transmission forms, such as, for example, radio frequency and optical transmissions, etc. The computer readable media may take the form of coded formats that are decoded for use in a particular data processing system.
[0111] Accordingly, one or more computer programs, or software components thereof, including instructions or code for performing the methodologies of the invention, as described herein, may be stored in one or more of the associated storage media (e.g., ROM, fixed or removable storage) and, when ready to be utilized, loaded in whole or in part (e.g., into RAM) and executed by the processor 1302 .
[0112] In any case, it is to be appreciated that the techniques of the invention, described herein and shown in the appended figures, may be implemented in various forms of hardware, software, or combinations thereof, e.g., one or more operatively programmed general purpose digital computers with associated memory, implementation-specific integrated circuit(s), functional circuitry, etc. Given the techniques of the invention provided herein, one of ordinary skill in the art will be able to contemplate other implementations of the techniques of the invention.
[0113] It is also to be appreciated that the methodologies described herein may be performed by one or more of the network elements and/or by a dedicated controller in the network.
[0114] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the invention. | Packet-aware transport architecture and techniques for implementing same that enhance data volume by scaling effectively to rapid data growth are disclosed. For example, a technique for determining a route for a demand in a circuit-switched network comprises the following steps/operations. The demand to be routed in the circuit-switched network is obtained. The circuit-switched networks implements a packet ring (PR) model such that one or more demands are routable on one or more virtual data rings in the circuit-switched network. An Ethernet-Over-SONET (EOS) communication channel in the circuit-switched network suitable for accommodating the demand is specified. The EOS communication channel or one of the one or more virtual data rings is then identified as the new route for the demand. | 7 |
BACKGROUND OF THE INVENTION
[0001] Adenoviral vectors for use in gene transfer to cells and especially in gene therapy applications, commonly are derived from adenoviruses by deletion of the early region 1 (E1) genes (Berkner, K. L., Curr. Top. Micro. Immunol. 158:39-66, 1992). Deletion of E1 genes renders such adenoviral vectors replication defective and significantly reduces expression of the remaining viral genes present within the vector. However, it is believed that the presence of the remaining viral genes in adenoviral vectors can be deleterious to the transfected cell for one or more of the following reasons: (1) stimulation of a cellular immune response directed against expressed viral proteins, (2) cytotoxicity of expressed viral proteins, and (3) replication of the vector genome leading to cell death.
[0002] One solution to this problem has been deleted adenoviral vectors, which are adenoviral vectors derived from the genome of an adenovirus containing minimal cis-acting nucleotide sequences required for the replication and packaging of the vector genome and which can contain one or more transgenes (See, U.S. Pat. No. 5,882,877 which covers pseudoadenoviral (“PAV”) or gutless vectors and methods for producing PAV, incorporated herein by reference). Such PAV vectors, which can accommodate up to 36 kb of foreign nucleic acid, are advantageous because the carrying capacity of the vector is optimized, while the potential for host immune responses to the vector or the generation of replication-competent viruses is reduced. Optimally, PAV vectors contain the 5′ inverted terminal repeat (ITR) and the 3′ ITR nucleotide sequences that contain the origin of replication, and the cis-acting nucleotide sequence required for packaging of the PAV genome, but do not comprise coding sequence for any adenoviral genes, and can accommodate one or more transgenes with appropriate regulatory elements.
[0003] Adenoviral vectors, including PAV, have been designed to take advantage of the desirable features of adenovirus which render it a suitable vehicle for nucleic acid transfer to recipient cells. Adenovirus is a non-enveloped, nuclear DNA virus with a genome size of about 36 kb, which has been well-characterized through studies in classical genetics and molecular biology (Horwitz, M. S., “Adenoviridae and Their Replication,” in Virology, 2nd edition, Fields et al., eds., Raven Press, New York, 1990). The viral genes are classified into early (designated E1-E4) and late (designated L1-L5) transcriptional units, referring to the generation of two temporal classes of viral proteins. The demarcation between these events is viral DNA replication. The human adenoviruses are divided into numerous serotypes (approximately 47, numbered accordingly and classified into 6 subgroups: A, B, C, D, E and F), based upon properties including hemagglutination of red blood cells, oncogenicity, DNA base and protein amino acid compositions and homologies, and antigenic relationships.
[0004] Recombinant adenoviral vectors have several advantages for use as gene transfer vectors, including tropism for both dividing and non-dividing cells, minimal pathogenic potential, ability to replicate to high titer for preparation of vector stocks, and the potential to carry large inserts (Berkner, K. L., Curr. Top. Micro. Immunol. 158:39-66, 1992; Jolly, D., Cancer Gene Therapy 1:51-64, 1994).
[0005] The cloning capacity of an adenovirus vector is proportional to the size of the adenovirus genome present in the vector. For example, a cloning capacity of about 8 kb can be created from the deletion of certain regions of the virus genome dispensable for virus growth, e.g., E3, and the deletion of a genomic region such as E1 whose function may be restored in trans from 293 cells (Graham, F. L., J. Gen. Virol. 36:59-72, 1977) or A549 cells (Imler et al., Gene Therapy 3:75-84, 1996). Such E1-deleted vectors are rendered replication-defective. The upper limit of vector DNA capacity for optimal carrying capacity is about 105%-108% of the length of the wild-type genome. Further adenovirus genomic modifications are possible in vector design using cell lines which supply other viral gene products in trans, e.g., complementation of E2a (Zhou et al., J. Virol. 70:7030-7038, 1996), complementation of E4 (Krougliak et al., Hum. Gene Ther. 6:1575-1586, 1995; Wang et al., Gene Ther. 2:775-783, 1995), or complementation of protein IX (Caravokyri et al., J. Virol. 69:6627-6633, 1995; Krougliak et al., supra).
[0006] Maximal carrying capacity can be achieved using adenoviral vectors deleted for most or all viral coding sequences, including PAVs (U.S. Pat. No. 5,882,877; Kochanek et al., Proc. Natl. Acd. Sci. USA 93:5731-5736, 1996; Parks et al., Proc. Natl. Acad. Sci. USA 93:13565-13570, 1996; Lieber et al., J. Virol. 70:8944-8960, 1996; Fisheretal., Virology 217:11-22, 1996; PCT Publication No. WO96/33280, published Oct. 24, 1996; PCT Publication No. WO96/40955, published December 19, 1996; PCT Publication No. WO97/25446, published Jul. 19, 1997; PCT Publication No. WO95/29993, published Nov. 9, 1995; PCT Publication No. WO96/13597, published May 9, 1996; PCT Publication No. WO97/00326, published Jan. 3, 1997; and PCT Publication No. WO99/57296. All of these documents are hereby incorporated by reference).
[0007] As noted above, PAV vectors can accommodate up to 36 kb of foreign nucleic acid (U.S. Pat. No. 5,882,877). Transgenes that have been expressed to date by adenoviral vectors include inter alia p53 (Wills et al., Human Gene Therapy 5:1079-188, 1994); dystrophin (Vincent et al., Nature Genetics 5:130-134, 1993); erythropoietin (Descamps et al., Human Gene Therapy 5:979-985, 1994); omithine transcarbamylase (Stratford-Perricaudet et al., Human Gene Therapy 1:241-256, 1990; We et al., J. Biol. Chem. 271; 3639-3646, 1996); adenosine deaminase (Mitani et al., Human Gene Therapy 5:941-948, 1994); interleukin-2 (Haddada et al., Human Gene Therapy 4:703-711, 1993); al-antitrypsin (Jaffe et al., Nature Genetics 1:372-378, 1992); thrombopoietin (Ohwada et al., Blood 88:778-784, 1996) and cytosine deaminase (Ohwada et al., Hum. Gene Ther., 7:1567-1576, 1996).
[0008] The use of adenoviral vectors in gene transfer studies to date indicates that persistence of transgene expression in target cells and tissues is often transient. At least some of the limitation is due to the generation of a cellular immune response to the viral proteins which are expressed antigenically even from a replication-defective vector, triggering a pathological inflammatory response which may destroy or adversely affect the adenovirus-infected cells (Yang et al., J. Virol. 69:2004-2015, 1995; Yang et al., Proc. Natl. Acad. Sci. USA 91:4407-4411, 1994 Zsellenger et al., Hum Gene Ther. 6:457-467, 1995; Worgall et al., Hum. Gene Ther. 8:37-44, 1997; Kaplan et al., Hum. Gene Ther. 8:45-56, 1997). Because adenovirus does not integrate into the cell genome, host immune responses that destroy virions or infected cells have the potential to limit adenovirus-based gene transfer. An adverse immune response poses a serious obstacle for high dose administration of an adenoviral vector or for repeated administration (Crystal, R., Science 270:404-410, 1995).
[0009] In order to circumvent the host immune response, which limits the persistence of transgene expression, various strategies have been employed, that generally involve either the modulation of the immune response itself or the engineering of a vector that decreases the immune response. The administration of immunosuppressive agents, together with vector administration, has been shown to prolong transgene persistence (Fang et al., Hum. Gene Ther. 6:1039-1044, 1995; Kay et al., Nature Genetics 11:191-197, 1995; Zsellenger et al., Hum. Gene Ther. 6:457-467, 1995; Scaria et al., Gene Therapy 4:611-617, 1997; WO98/08541).
[0010] Modifications to genomic adenoviral sequences contained in the recombinant vector have been attempted in order to decrease the host immune response (Yang et al., Nature Genetics 7:362-369, 1994; Lieber et al., J. Virol. 70:8944-8960, 1996; Gorziglia et al., J. Virol. 70:4173-4178; Kochanek et al., Proc. Natl. Acad. Sci. USA 93:5731-5736, 1996; Fisher et al., Virology 217:11-22, 1996). The adenovirus E3 gp19K protein can complex with MHC Class I antigens and retain them in the endoplasmic reticulum, which prevents cell surface presentation and killing of infected cells by cytotoxic T-lymphocytes (CTLs) (Wold et al., Trends Microbiol. 437-443, 1994), suggesting that its presence in a recombinant adenoviral vector may be beneficial. Other adenovirus modifications have shown promise in delivering transgenes to target cells, with persistent transgene expression having resulted therefrom (see, e.g. WO98/46781, WO98/46780, and WO98/46779 and Scaria et al., J. Virol., 72:7302-7309, 1998). The lack of persistence in the expression of adenoviral vector-delivered transgenes may also be due to limitations imposed by the choice of promoter or transgene contained in the transcription unit (Guo et al., Gene Therapy 3:802-801, 1996; Tripathy et al., Nature Med. 2:545-550, 1996). Further optimization of minimal adenoviral vectors for persistent transgene expression in target cells and tissues also involves the design of expression control elements, such as promoters, which confer persistent expression to an operably linked transgene. Promoter elements, which function independently of particular viral genes to confer persistent expression of a transgene, allow the use of vectors containing reduced viral genomes.
[0011] In addition to containing the inverted terminal repeat sequences, PAV vectors also contain a cis-acting packaging sequence, normally located at the 5′ end of the wild-type adenoviral genome. The packaging sequence contains seven functional elements, identified as A repeats (Schmid et al., J. Virol. 71:3375-3384, 1997).
[0012] Production of PAV or other minimal adenoviral vectors requires the provision of adenovirus proteins in trans which facilitate the replication and packaging of a PAV genome (and inserted foreign nucleic acid) into viral vector particles for use in gene transfer. Most commonly, such genes are provided by infecting the producer cell with a helper adenovirus containing the necessary genes. However, such viruses are potential sources of contamination of the PAV vector stock during purification if they are able to replicate and be packaged into viral particles. It is advantageous, therefore, to increase the purity of a PAV stock by reducing or eliminating the production of helper viruses that contaminate the preparation. Several strategies to reduce the production of helper viruses in the preparation of PAV and other partially deleted adenoviral stocks are disclosed in U.S. Pat. No. 5,882,887, PCT application WO99/57296 and international application No. PCT/US99/03483, filed Feb. 17, 1999 all of which are hereby incorporated herein by reference. For example, the helper virus can contain mutations in the packaging sequence of its genome which prevent packaging, or may contain an oversized adenoviral genome which cannot be packaged.
[0013] Novel helper viruses which facilitate the production of pseudoadenoviral vectors (PAV) by providing essential viral proteins in trans, but which are packaging defective due to the inclusion of binding sequences for repressor proteins that prevent utilization of the packaging signals in the helper virus genome have been disclosed in PC/US99/03483, filed Feb. 17, 1999, incorporated herein by reference. The PCT application also provides PAV producer cell lines expressing such repressor proteins and to methods for the production of PAV using such helper viruses and producer cell lines.
[0014] Recently, PAV helper viruses have been described in which packaging of the helper is reduced through the use of the Cre/Lox system (Parks et al., Proc. Natl. Acad. Sci. USA 93:13565-13570, 1996). Lox sites are placed at positions flanking the Ad packaging sequences in the helper viral genome, which is produced in conventional 293 cells. For PAV production, a Cre-expressing 293 cell is employed. The helper genome can replicate and express viral genes so that the PAV genome can be packaged, but the packaging sequences are deleted from the helper through the action of the Cre protein.
[0015] However, methods of producing helper-dependent adenoviral vectors, such as PAV, have not been maximized; measurable amounts of helper virus can remain in vector preparations. In addition, current methods of PAV production are not readily scalable for larger scale commercial uses.
[0016] The present invention provides an alternative adenoviral vector system in which the helper adenovirus contains packaging elements of a different serotype than that of the recombinant helper-dependent adenoviral vector. Because of the serotype differences, the packaging sequences present in the helper-dependent adenoviral vector have reduced ability to package the helper adenovirus. Accordingly, the ability of the helper adenovirus to become encapsidated, through recombination events, is significantly reduced, and significantly reduced amount of encapsidated helper adenovirus is produced.
[0017] Novel methods of manufacturing the PAV and other helper dependent adenoviral Ad vector and an advanced vector system for use in producing PAV, both in scaleable amounts, are also provided.
SUMMARY OF THE INVENTION
[0018] Accordingly, the present invention provides methods and materials for the production of helper-dependent adenovirus, such as PAV, at high titers. In certain embodiments, the invention comprises methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with: (a) a helper-dependent adenoviral vector comprising inverted terminal repeats (ITRs) and packaging sequence derived from a first adenoviral serotype, and a transgene of interest flanked by said ITRs; and (b) a chimeric packaging-deficient helper adenovirus which contains adenoviral genes derived from the first adenoviral serotype, and ITRs and packaging sequence derived from a second adenoviral serotype; and collecting the virions produced thereby.
[0019] In certain preferred embodiments, the invention comprises methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with: (a) a helper-dependent adenoviral vector comprising a ITRs and a packaging sequence derived from a first adenoviral serotype, preferably Ad2, and a transgene of interest flanked by said inverted terminal repeats (ITRs); and (b) a chimeric packaging-deficient helper adenovirus which contains adenoviral genes derived from the first adenoviral serotype, and a packaging sequence derived from a second adenoviral serotype; and collecting the virions produced thereby. In this embodiment, the serotype origin of the ITRs flanking the chimeric packaging-deficient helper adenovirus may be derived from either the first adenoviral serotype or the second adenoviral serotype, but is preferably of the first adenoviral serotype, which is preferably Ad2.
[0020] The helper-dependent adenoviral vector is preferably a deleted adenoviral vector, such as a pseudoadenoviral vector, and its ITRs and packaging sequence are preferably derived from adenoviral subgroup C, more preferably from adenoviral serotypes 2, 5, 6 or 1, and most preferably from adenoviral serotypes 2 or 5. The helper-dependent adenoviral vector may also be derived from other adenoviral subgroups.
[0021] The packaging sequence, and in certain cases, the ITRs, of the chimeric, packaging-deficient helper adenovirus are preferably derived from an adenoviral subgroup other than the subgroup from which are derived the ITRs and packaging sequence of the helper-dependent adenoviral vector, [for example, A, B, D, E or F when the helper-dependent adenoviral vector contains ITRs and packaging sequences derived from adenoviral subgroup C]. The chimeric, packaging-deficient helper adenoviruses preferably contain one or more adenoviral genes, which have been deleted from the helper-dependent adenoviral vector. The adenoviral genes are of the same adenoviral subgroup or serotype as the ITRs and packaging sequence of the helper-dependent adenoviral vector. In the preferred embodiment wherein the ITRs and packaging sequence of the helper-dependent adenoviral vector is derived from adenoviral subgroup C, the ITRs and packaging sequence of the chimeric, packaging-deficient helper adenovirus are preferably from adenoviral subgroup B or D, and most preferably from adenoviral serotype 7 or 17, respectively, while the adenoviral genes of the helper adenovirus are derived from the subgroup C. Where the ITRs and packaging sequence of the helper-dependent adenoviral vector is derived from other adenoviral subgroups, the adenoviral genes of the chimeric, packaging-deficient helper adenovirus is preferably of the same subgroup, and the ITRs and packaging sequence of the chimeric, packaging-deficient helper adenovirus is preferably selected from a second adenoviral subgroup which is distinct from that of the helper-dependent adenoviral vector. For example, if the helper-dependent adenoviral vector comprises ITRs and packaging sequence derived from subgroup B, the chimeric, packaging-deficient helper adenovirus preferably comprises ITRs and packaging sequence from a subgroup other than B [e.g., A, C, D, E or F]. Within the ITRs, the helper adenovirus preferably comprises one or more adenoviral genes of the same subgroup as the helper-dependent adenoviral vector [e.g., subgroup B]. These adenoviral genes will provide the critical elements that are missing from the helper-dependent adenoviral vector, and allow the adenoviral vector to replicate and be encapsulated.
[0022] Other embodiments of the present invention include methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with: (a) a helper-dependent adenoviral vector comprising inverted terminal repeats (ITRs) and packaging sequence [ψ] derived from a first adenoviral serotype from subgroup C, a transgene of interest flanked by said ITRs; and (b) a chimeric helper adenovirus with packaging sequence [ψ] derived from adenoviral subgroup B or D, and adenoviral genes derived from the first adenoviral serotype; and then collecting the virions produced from the co-transfected cell. The helper-dependent adenoviral vector is preferably a deleted adenoviral vector, such as a pseudoadenoviral vector. The adenoviral serotype of the helper-dependent adenoviral vector is preferably adenovirus 2 or 5. The ITRs of the chimeric helper adenovirus is preferably derived from the first adenoviral serotype or the second adenoviral serotype.
[0023] In other embodiments, the invention comprises chimeric, packaging-deficient helper adenoviruses useful for the propagation of helper-dependent adenoviral vectors of a first adenoviral serotype. The chimeric helper adenovirus comprises adenoviral genes derived from a first adenoviral serotype, preferably of subgroup C, and packaging sequence [ψ] derived from a second adenoviral serotype, preferably of subgroup A, B, D or E, more preferably subgroup B or D. The ITRs of the chimeric helper adenovirus is preferably derived from the first adenoviral serotype or the second adenoviral serotype. In a preferred embodiment, the chimeric, packaging-deficient helper adenovirus comprises adenoviral genes derived from an adenoviral serotype selected from the group consisting of serotypes 2 and 5, and ITRs and packaging sequence derived from an adenoviral serotype selected from the group consisting of serotypes 7 and 17.
[0024] The present invention is further directed to methods for production of helper-dependent adenoviral vectors. Such helper-dependent adenoviral vectors include pseudoadenoviral (“PAV”) or “gutless” adenoviral vectors. Helper-dependent adenoviral vectors are being developed for a variety of gene therapy applications. The vectors retain the cis elements required for DNA replication and packaging such as the inverted terminal repeats (ITRs) and packaging signal ( ) but may be devoid of all other adenoviral coding regions, which may be replaced by an expression cassette of interest and “stuffer” sequences. The viral gene products required for virus growth and encapsidation must therefore be supplied in trans by a helper virus in order to produce PAV. In current schemes, both the helper-dependent virus and the helper virus are derived from the same adenovirus serotype and PAV is co-propagated with helper virus which leads to the production of both vectors within the cell. Several strategies have been employed to reduce the presence of helper in virus preparations.
[0025] One strategy is based on constructing PAV and helper with different genomic lengths such that PAV and helper virus particles can be separated by CsCl density gradient centrifugation. Another is based on modifying the packaging signals within PAV and/or the helper virus such that the helper becomes less efficiently encapsidated. A third strategy, which is the most efficient, is based on Cre/Lox mediated excision of the packaging signal from the helper in the producer cell resulting in 100-1000 fold reduction of encapsidation. All these strategies yield some helper virus contamination in the PAV preparation and tend to generate replication competent adenovirus.
[0026] Thus, in one embodiment, the present invention comprises methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with: (1) a helper-dependent adenoviral vector comprising inverted terminal repeats (ITRs) and packaging sequence [ψ] derived from a first adenoviral subgroup, and a transgene of interest flanked by said ITRs; and (2) a packaging-deficient helper adenovirus which contains adenoviral genes derived from a first adenoviral subgroup, but packaging sequence [ψ] from a second adenoviral subgroup; and collecting virions produced thereby. The ITRs of the helper adenovirus may preferably be derived from either the first or second adenoviral subgroup.
[0027] The packaging sequence [ψ] of the helper adenoviral vector is preferably selected from the group consisting of subgroup B and subgroup D, more preferably selected serotype 7 and serotype 17, respectively. The adenoviral genes in the helper are preferably selected from subgroup C. The packaging-deficient helper virus may contain mutations in the packaging sequence of its genome which prevent packaging, or may contain an oversized adenoviral genome which cannot be packaged. Alternatively, packaging of the helper virus may reduced through the use of the Cre/Lox system or other recombinase. The ITRs of the helper adenovirus may preferably be derived from either the first or second adenoviral subgroup.
[0028] The ITRs and packaging sequence [ψ] of the helper-dependent adenoviral vector are preferably derived from adenovirus subgroup C, more preferably derived from the adenovirus serotype 2 or serotype 5.
[0029] In other embodiments, the present invention comprises methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with both (1) a helper-dependent adenoviral vector comprising ITRs and packaging sequence [ψ] derived from a first adenoviral serotype, and a transgene flanked by said ITRs; and (2) a chimeric helper adenoviral vector comprising packaging sequence [ψ] derived from a second adenoviral serotype, adenoviral genes derived from the first adenoviral serotype, and inverted terminal repeats (ITRs) derived from either the first or second adenoviral serotype; and then collecting virions produced thereby.
[0030] In preferred embodiments of the invention, the helper-dependent adenoviral vector is a partially or fully deleted adenoviral vector. In the most preferred embodiment, the helper-dependent adenoviral vector is a fully deleted pseudoadenoviral vector. The helper-dependent adenoviral vector preferably comprises ITRs and packaging sequences [ψ] derived from adenoviral subgroups C, and more preferably the ITRs and packaging sequences [ψ] are derived from adenoviral serotypes 2, 5, 6 or 1.
[0031] The helper adenovirus useful in the methods of the present invention is preferably a chimeric adenovirus which contains a full complement of the adenoviral genome. Alternatively, the helper adenovirus may be a chimeric adenovirus which contains adenoviral genes to complement the adenoviral functions which have been deleted from the helper-dependent adenoviral vectors which the helper adenovirus is designed to support. In either case, one or more of the adenoviral genes is preferably derived from the same adenoviral subgroup as the helper-dependent adenoviral vector it is designed to support, while the packaging sequence of the helper adenovirus is derived from a second subgroup. The ITRs of the helper adenovirus are preferably derived from either the first adenoviral subgroup or the second adenoviral subgroup. In preferred embodiments, the adenovirus E1 genes in the helper are preferably from adenovirus subgroup C, and is more preferably of adenoviral serotype 2, 5, 6 or 1, most preferably derived from adenoviral serotype 2 or 5. Alternatively, or in addition, the helper adenovirus may be packaging-deficient. For example, the helper adenovirus can contain mutations in the packaging sequence of its genome which prevent packaging, or may contain an oversized adenoviral genome which cannot be packaged.
[0032] Other helper viruses useful in the present invention may be packaging defective due to the inclusion of binding sequences for repressor proteins that prevent utilization of the packaging signals in the helper virus genome, or in which packaging of the helper is reduced through the use of the Cre/lox or other recombinase system. Examples of other recombinase systems that can be used include Flp recombinase (Senecoff et al., 1985, Proc. Natl. Acad. Sci. USA 82:7270-7274; Buchholz et al., 1998, Nature Biotechnol. 16:657-662; Buchholz et al., 1996, NAR 24:4256-4262), and the phage [φ] C31 recombinase system is described in Kuhstoss and Rao, J. Mol. Biol. 222:897-908 (1991); U.S. Pat. No. 5,190,981; Groth et al., PNAS Early Edition , www.pnas.org/cgi/doi/10.1073/pnas.090527097; and PCT Patent Publication WO00/11155. There are currently approximately 105 proteins in subgroups of site specific recombinases. See generally, Nunes-Duby et al., 1998, Nucleic Acids Res. 26:391-406; Argos et al., 1986, EMBO J. 5:433-440. In addition to the above recombinases, a recombinase (R) encoded by the pSR1 plasmid of the yeast Zygosaccharomyces rouxii has similar function to FLP (Kilby et al., 1993, TIG 9:413-421). The “R” recombinase and its recognition sequences may also facilitate the binding and recombination referred to herein. The disclosure of all of these publications is hereby incorporated herein by reference.
[0033] In other embodiments, the present invention comprises helper-dependent adenoviral vectors. The helper-dependent adenoviral vectors of the present invention preferably comprise inverted terminal repeats (ITRs) and packaging sequence, and a transgene of interest flanked by said ITRs. In preferred embodiments of the invention, the helper-dependent adenoviral vector is a pseudoadenoviral vector, which contains no coding sequences for adenoviral genes. In preferred embodiments, the ITRs and packaging sequence are derived from an adenoviral serotype selected from the group consisting of adenovirus subgroup C, more preferably from adenovirus serotype 2, 5, 6 or 1, more preferably from adenovirus serotypes 2 or 5.
[0034] Thus, in certain embodiments, the present invention comprises a chimeric helper adenovirus which contains a packaging sequence [ψ] derived from a different adenoviral serotype subgroup than that of the adenoviral genome of the helper adenovirus, said packaging sequence being flanked by target sites of recombination such as lox sites, for use with the Cre/lox system. This is where the utility of using a chimeric packaging signal lies. Thus, in such embodiments of the invention, the packaging signal of the chimeric adenovirus may be flanked by lox sites. In the use of a helper adenovirus using the Cre/lox system, if there is a recombination event of a helper adenovirus with PAV or with 293 sequences in the packaging signal, it results in the loss of one of the lox sites surrounding the packaging signal. This in turn results in the failure of the packaging signal to be excised from the helper and thus during the expansion process, PAV preparations will be contaminated with helper. With the chimeric packaging signal, such recombination events, and thus, such contamination, will be greatly reduced.
[0035] Description of the Sequences:
[0036] Sequence ID NO: I is a nucleotide sequence from the ITR and y sequences of Ad serotype 2.
[0037] Sequence ID NO:2 is a nucleotide sequence from the ITR and ψ sequences of Ad serotype 4.
[0038] Sequence ID NO:3 is a nucleotide sequence from the ITR and ψ sequences of Ad serotype 7.
[0039] Sequence ID NO:4 is a nucleotide sequence from the ITR and ψ sequences of Ad serotype 12.
[0040] Sequence ID NO:5 is a nucleotide sequence from the ITR and ψ sequences of Ad serotype 17.
BRIEF DESCRIPTION OF THE FIGURES
[0041] [0041]FIG. 1 illustrates the alignment of ITR and ψ sequences from Ad2 (subgroup C) with Ad12 (subgroup A).
[0042] [0042]FIG. 2 illustrates the alignment of ITR and ψ sequences from Ad7 (subgroup B) with Ad2 (subgroup C).
[0043] [0043]FIG. 3 illustrates the alignment of ITR and ψ sequences from Ad17 (subgroup D) with Ad2 (subgroup C).
[0044] [0044]FIG. 4 illustrates the alignment of ITR and ψ sequences from Ad4 (subgroup E) with Ad2 (subgroup C).
[0045] [0045]FIG. 5 illustrates constructs generated containing either the Ad7 or Ad17 ITRs +/−ψ sequences linked to ad Ad2 genome in which the El region was deleted and replaced with a β-galactosidase expression cassette. Ad2-p7 and Ad2-7 contain the ITRs +/−ψ sequences from Ad7, respectively and Ad2-p17 and Ad2-17 contain the ITRs +/−ψ sequences from Ad17, respectively. Ad2-EGFP is a positive control virus that is entirely derived from Ad2 in which the E1 region was deleted and replaced with a green fluorescent protein expression cassette.
[0046] [0046]FIG. 6. Panel A illustrates various assays that were conducted for analysis of viral replication and packaging. Plasmids were digested with SnaBI and the DNAs were transfected into parallel cultures of 293 cells. The ability of the constructs to replicate over a time course of 0 to 96 hours post-transfection was monitored by Southern analysis, illustrated in FIG. 6, panel B.
[0047] [0047]FIG. 7 shows the results of plaque assays. For both the Ad2-p7 and Ad2-p17 constructs virus titer is reduced more that one order of magnitude compared to positive control, pAd2EGFP. In addition, the appearance of plaques is delayed by 3-4 days.
[0048] [0048]FIG. 8 illustrates the yield of Ad2-p7 is increased by more that three orders of magnitude when cultures are co-infected with wild type Ad7 virus while the yield remains unchanged in cultures co-infected with wild type Ad2. This suggests that the wild type Ad7 virus can supply a factor(s) in trans that rescues the Ad2-p7 virus. Similar results were observed with Ad2-p 17.
[0049] [0049]FIG. 9 illustrates the relative titers of vector [Ad2-β-ga14] and chimeric helper adenovirus [Ad2-ψ17] with packaging sequence derived from Ad17.
[0050] [0050]FIG. 10 shows the alignment of Ad2 and Ad 1 7 packaging sequences. Sequences shown in bold are the A repeats in the packaging signal. Sequences underlined are enhancer regions. One of the problems encountered in the scale up of PAV (helper dependent adenoviral vector) is recombination between the helper and PAV. This is particularly important in strageges that use a recombinase/target sequence such as the Cre-lox system to excise the packaging signal from the helper in order to reduce helper contamination. A recombination event in the ψ region would lead to loss of the ability to remove ψ from the helper. The ψ regions share approximately 74% homology and since Ad17 ψ functions in the context of an Ad2 based vector, this might be incorporated into helper vectors as one strategy to reduce recombination between helper and PAV.
DETAILED DESCRIPTION OF THE INVENTION
[0051] Adenovirus DNA replication is well understood and both viral and cellular components that are required for this process have been identified for different adenovirus subgroups. Adenoviral DNA encapsidation is less understood. Encapsidation or packaging signal sequences (ψ) have been identified for subgroup C viruses as well as cellular factors that bind to these sequences. Not all of the identified subgroup C packaging signal elements are conserved in viruses from other subgroups and the overall homology of the ITR and packaging signal region of subgroup C viruses with other subgroup members ranges from 60-68%. FIGS. 1 - 4 show the alignment of ITR and ψ sequences from Ad2 (subgroup C) with Ad12 (subgroup A), Ad7 (subgroup B), Ad17 (subgroup D) and Ad4 (subgroup E), respectively.
[0052] The invention is based on the observation that viruses from different subgroups do not efficiently cross-package each other due to differences in the required packaging signal sequences (both known and unknown) and differences in viral proteins that direct subgroup specific packaging. The invention is directed to novel helper adenoviruses for the production of helper-dependent adenoviral vectors, such as PAV. A helper vector could contain the packaging signal +/− the ITRs from one subgroup but contain the remainder of the genome of the subgroup from which PAV is derived. This would require a complementing cell line that supplies the packaging factor(s) in trans for packaging the helper. The helper can then be used in a non-complementing cell line to generate PAV. In this scenario, the helper will replicate and package PAV but packaging of the helper will be compromised.
[0053] Cell lines useful in the methods of the present invention include those cell lines which are permissive for adenoviral replication and packaging, including, but not limited to human 293 embryonic kidney cells, A549 embryonic kidney cells, and PerC6 embryonic retinal cells.
[0054] Most cell lines presently in use are derived from human 293 embryonic kidney cells, which contain an E1 adenoviral gene, ITRs and packaging sequence derived from the adenovirus 2 serotype. In order to reduce the potential for recombination between a helper adenovirus and the E1 cell line to generate unwanted replication-competent adenovirus, it is preferred that the chimeric helper adenovirus of the present invention comprise packaging sequences from a serotype other than adenovirus 2 serotype. In addition, the ITRs of the chimeric helper adenovirus may preferably be derived from a serotype other than adenovirus 2 serotype.
[0055] The invention is also directed at generating helper vectors that have a reduced potential for recombination with PAV. ITRs on the helper and PAV can be derived from different subgroups to reduce the potential for recombination. As shown in FIGS. 1 - 4 the homologies of ITRs between subgroups ranges from 60-80%.
[0056] The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended only as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various embodiments and modifications of the invention, in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and the examples which follow. Such modifications also fall within the scope of the appended claims. Various references and publications are cited within this specification, and the disclosures of all of which are hereby incorporated herein by reference in their entireties.
EXAMPLES
[0057] Chimeric first generation adenovirus vectors were constructed to determine if the ITRs and ψ from other subgroups would allow replication and packaging of an otherwise Ad2 genome. FIG. 5 depicts constructs that were generated containing either the Ad7 or Ad17 ITRs +/−ψ sequences linked to an Ad2 genome in which the E1 region was deleted and replaced with a β-galactosidase expression cassette. Ad2-p7 and Ad2-7 contain the ITRs +/−ψ sequences from Ad7, respectively and Ad2-p17 and Ad2-17 contain the ITRs +/−ψ sequences from Ad17, respectively. Ad2-EGFP is a positive control virus that is entirely derived from Ad2 in which the E1 region was deleted and replaced with a green fluorescent protein expression cassette. All vectors contain a 2.9kb deletion in the E3 region. The constructs were generated in plasmid form from which the chimeric genomes could be excised by digestion with restriction endonuclease SnaBI.
[0058] [0058]FIG. 6, panel A schematically depicts the various assays that were done for analysis of viral replication and packaging. Plasmids were digested with SnaBI and the DNAs were transfected into parallel cultures of 293 cells. The ability of the constructs to replicate over a time course of 0 to 96 hours post-transfection was monitored by Southern analysis, shown in FIG. 6, panel B. DNA replication of Ad2-p7 and Ad2-7 appear to exhibit similar kinetics to the positive control vector, Ad2-EGFP, indicating that the Ad2 (subgroup C) replication machinery can replicate DNA containing ITRs derived from Ad7 (subgroup B). DNA replication of Ad2-p17 and Ad2-17 appears to be delayed and is not detected until 48 hours post transfection. By later time points however, the DNAs accumulate to similar amounts as Ad2-EGFP indicating that although delayed, the Ad2 replication machinery can replicate DNA containing ITRs derived from Ad17 (subgroup D. Constructs that do not contain a packaging signal appear to replicate with similar kinetics to their counterparts that do suggesting that the packaging signal is dispensable for DNA replication.
[0059] Cultures harvested at 96 hours post-transfection were subjected to three freeze-thaw cycles and the released virus was titered by plaque assay. The results of each experiment shown in FIG. 7 represent the averages from duplicate samples. For both the Ad2-p7 and Ad2-p17 constructs virus titer is reduced more that one order of magnitude. In addition, the appearance of plaques is delayed by 3-4 days. This indicates that while the DNAs can be replicated, they are not efficiently being incorporated into virus particles. This suggests that a subgroup specific factor(s) might be involved packaging signal recognition and that the Ad2 factors less efficiently package genomes containing packaging signals derived from other subgroups. This phenomenon would be reflected in reduced titers and delayed plaque formation.
[0060] Cultures were also overlayed following transfection and the number of plaques was scored.
[0061] This was done as a control for transfection efficiency. While the number of plaques obtained was lower for Ad2-p7 and Ad2-p17 the differences in virus yield cannot be accounted for by this variation. In addition, the appearance of plaques was delayed for these constructs compared to the Ad2-EGFP control virus.
[0062] In order to determine if a subgroup specific factor(s) was involved in packaging, rescue experiments were performed. Titered Ad2-p7 and Ad2-p17 virus was used to infect 293 cells either alone or with wild type virus (either Ad2 or the serotype from which the ITRs were derived). Forty-eight hours post-infection the cultures were harvested and were subjected to three freeze-thaw cycles. The released virus was titered by hexon staining to measure total virus yield and by X-gal staining to measure chimeric virus yield. As shown in FIG. 8, the yield of Ad2-p7 is increased by more that three orders of magnitude when cultures are co-infected with wild type Ad7 virus while the yield remains unchanged in cultures co-infected with wild type Ad2. This suggests that the wild type Ad7 virus can supply a factor(s) in trans that rescues the Ad2-p7 virus. A similar result is observed for Ad2-p17. The yield of this virus is also increased by more than three orders of magnitude when cultures are co-infected with wild type Ad17 whereas the yield remains unchanged in cultures co-infected with wild type Ad2. This suggests that wild type Ad17 virus can supply a factor(s) in trans that rescues the Ad2-p 17 virus.
[0063] In order to determine if the packaging signal (ψ) directs subgroup specific packaging, a construct was generated that is solely derived from Ad2 except for ψ. Ad2-ψ17, shown in panel A, is Ad2-based but contains ψ from Ad 17 and was generated by transfection into 293 cells. This virus was expanded in PerC.6 cells and analyzed for virus yield in the presence or absence of wild type Ad17. As shown, the titer of Ad2-ψ17, unlike Ad2-p17 (FIG. 9), does not increase when it is grown in the presence of wild type Ad17. This suggests that supplying Ad17 functions in trans does not increase titer and that elements involved in subgroup specific packaging lie outside of the ψ region. The yield of Ad2-ψ17 compared to Ad2/βgal-4 which is completely Ad2-based is modestly affected suggesting that the Ad17 ψ can function in place of Ad2 ψ, but less efficiently. The titer of Ad2-ψ17 is not affected when grown in the presence of Ad2/βgal-4, further supporting the interchangeability of the ψ regions.
[0064] From the above, it can be concluded that packaging of adenovirus is subgroup specific, and that elements involved in subgroup specific packaging lie outside of the conventional the ψ regions. Thus, incorporation of non-Ad2 ψ sequences into helper vectors for use with helper dependent vectors derived from Ad2, such as PAV, may be a useful strategy for reducing recombination between helper and PAV in the scale-up process. This is particularly important in strategies that use a recombinase/target sequence such as the Cre-lox system to excise the packaging signal from the helper in order to reduce helper contamination. A recombination event in the ψ region would lead to loss of the ability to remove ψ from the helper.
1
5
1
378
DNA
adeno-associated virus 2
1
catcatcata atatacctta ttttggattg aagccaatat gataatgagg gggtggagtt 60
gtgacgtgg cgcggggcgt gggaacgggg cgggtgacgt agtagtgtgg cggaagtgtg 120
tgttgcaag tgtggcggaa cacatgtaag cgccggatgt ggtaaaagtg acgtttttgg 180
gtgcgccgg tgtatacggg aagtgacaat tttcgcgcgg ttttaggcgg atgttgtagt 240
aatttgggc gtaaccaagt aatgtttggc cattttcgcg ggaaaactga ataagaggaa 300
gtgaaatctg aataattctg tgttactcat agcgcgtaat atttgtctag ggccgcgggg 360
actttgaccg tttacgtg 378
2
391
DNA
adenovirus serotype 04
2
atctatataa tataccttat tttttttgtg tgagttaata tgcaaataag gcgtgaaaat 60
ttggggatgg ggcgcgctga ttggctgtga cagcggcgtt cgttaggggc ggggcaggtg 120
acgttttgat gacgcgacta tgaggaggag ttagtttgca agttctggtg gggaaaagtg 180
acgtttttgg tgtgcgccgg tgtatacggg aagtgacaat tttcgcgcgg ttttaggcgg 240
atgttgtagt aaatttgggc gtaaccaagt aatgtttggc cattttcgcg ggaaaactga 300
ataagaggaa gtgaaatctg aataattctg tgttactcat agcgcgtaat atttgtctag 360
ggccgcgggg actttgaccg tttacgtgga g 391
3
434
DNA
adenovirus serotype 07
3
ataatatacc ttatagatgg aatggtgcca acatgtaaat gaggtaattt aaaaaagtgc 60
gcgctgtgtg gtgattggct gtggggtgaa tgactaacat gggcggggcg gccgtgggaa 120
aatgacgtga cttatgtggg aggagttatg ttgcaagtta ttgcggtaaa tgtgacgtaa 180
aaggaggtgt ggtttacatg taagcgccgg atgtggtaaa agtgacgttt ttggtgtgcg 240
ccggtgaaca cggaagtaga cagttttccc acgcttactg ataggatatg aggtagtttt 300
gggcggatgc aagtgaaaat tctccatttt cgcgcgaaaa ctgaatgagg aagtgaattt 360
ctgagtcatt tcgcggttat gacagggtgg agtatttgcc gagggccgag tagactttga 420
ccgtttacgt ggag 434
4
324
DNA
adenovirus serotype 12
4
taataatata ccttatactg gactagtgcc aatattaaaa tgaagtgggc gtagtgtgta 60
atttgattgg gtggaggtgt ggctttggcg tgcttgtaag tttgggcgga tgaggaagtg 120
gggcgcggcg tgggagccgg gcgcgccgga tgtgacgttt tagacgccat tttacacgga 180
aatgatgttt tttgggcgtt gtttgtgcaa attttgtgtt ttaggcgcga aaactgaaat 240
gcggaagtga aaattgatga cggcaatttt attataggcg cggaatattt accgagggca 300
gagtgaactc tgagcctcta cgtg 324
5
390
DNA
adenovirus serotype 17
5
gcatcatcaa taatataccc cacaaagtaa acaaaagtta atatgcaaat gaggttttaa 60
atttagggcg gggctactgc tgattggccg agaaacgttg atgcaaatga cgtcacgacg 120
cacggctaac ggtcgccgcg gaggcgtggc ctagcccgga agcaagtcgc ggggctgatg 180
acgtataaaa aagcggactt taaacccgga aacggccgat tttcccgcgg ccacgcccgg 240
atatgaggta attctgggcg gatgcaagtg aaattaggtc attttggcgc gaaaactgaa 300
tgaggaagtg aaaagtgaaa aataccggtc ccgcccaggg cggaatattt accgagggcc 360
gagagacttt gaccgattac gtgtgggttt 390 | The present invention provides methods and materials for the production of helper-dependent adenovirus, such as PAV, at high titers. In one embodiment, the invention comprises methods for producing high titers of helper-dependent adenovirus comprising co-transfecting a cell permissive for production of adenovirus with: (a) a helper-dependent adenoviral vector comprising inverted terminal repeats (ITRs) and packaging sequence derived from a first adenoviral serotype, and a transgene of interest flanked by said ITRs; and (b) a chimeric, packaging-deficient helper adenovirus which contains adenoviral genes derived from the first adenoviral serotype, packaging sequence derived from a second adenoviral serotype, and ITRs derived from either the first or second adenoviral serotypes; and collecting virions produced thereby. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to playing card wagering games that can be played with playing cards, including a standard deck of cards or by video machine technology in a casino or home environment. In particular, it relates to a method and apparatus for playing a wagering game, wherein the game is a variation of five card stud poker and provides players the opportunity to take or leave a portion of their wager during the course of the game.
2. Background of the Art
There are many wagering games used for gambling. Such games should be exciting to arouse players' interest and uncomplicated so they can be understood easily by a large number of players. Ideally, the games should include more than one wagering opportunity during the course of the game, yet be able to be played rapidly to a wager resolving outcome. Exciting play, the opportunity to make more than one wager and rapid wager resolution enhance players' interest and enjoyment because the frequency of betting opportunities and bet resolutions is increased.
Wagering games, particularly those intended primarily for play in casinos, should provide players with a sense of participation and control, the opportunity to make decisions, and reasonable odds of winning, even though the odds favor the casino, house, dealer or banker. The game must also meet the requirements of regulatory agencies.
Wagering games, including wagering games for casino play, with multiple wagering opportunities are known. U.S. Pat. Nos. 4,861,041 and 5,087,405 (both to Jones et al.) disclose methods and apparatus for progressive jackpot gaming, respectively. The former patent discloses that a player may make an additional wager at the beginning of a hand, the outcome of the additional wager being determined by of a predetermined arrangement of cards in the player's hand. U.S. Pat. No. 4,836,553 (to Suttle and Jones) discloses a modified version of a five card stud poker game.
Additional symbols may be added to the usual means of playing a game to increase wagering opportunities. This is disclosed in U.S. Pat. No. 5,098,107 (to Boylan et al.). Somewhat similarly, U.S. Pat. No. 3,667,757 (to Holmberg) discloses a board game and apparatus, including a way to allow the player to make a choice with respect to several different alternative types of game play and risk bearing strategies. The alternative play is based on providing cards with additional symbols and therefore, a new set of odds. The game and apparatus disclosed by Holmberg requires new sets of rules, relatively complicated procedures and time for a player to learn the game.
U.S. Pat. No. 5,154,429 (to LeVasseur) involves the dealer playing multiple hands against a player's single hand, whereby the number of hands played in the same amount of time is increased.
U.S. Pat. No. 5,288,081 (Breeding) describes the game Let It Ride® stud poker which is played in many casinos around the world. That wagering game is played with a single, typical (standard) fifty-two card poker deck and broadly involves the generally well recognized and accepted set of rules, procedures and wager-resolving outcomes of five card poker. The game method comprises each player placing an initial, three-part wager (all bet parts are equal) to participate in the game. A separate bonus wager (a side bet wager) may be placed to play against a pay table. Cards are dealt by a dealer, three down to each player and two down to the dealer. Players inspect or “sweat” their cards, and the dealer asks “take it or leave it?” or as the name of the game implies, “Let It Ride®?” with regard to the first part of the initial bet. Players can choose to retrieve or remove from play the first part of their initial bet, or leave the first part in play or at risk, based on the value of the three cards in their hand. The side wager or bonus wager cannot be withdrawn and is immediately withdrawn by the house in the play of the game. The dealer then turns over one of the dealer's cards and the dealer's query is repeated with regard to the second part of the initial bet. Players can choose to retrieve or remove from play the second part of their initial bet or leave the second part in play or at risk, based on the value of the four cards consisting of the three cards in the player's hand and the exposed dealer's card. Players have no option with the third part of the bet. Finally, all cards are shown and the payouts and collections are resolved according to the ranking of the poker hand of each player, i.e., the players are not playing against each other or the dealer.
Another element of play in casino games and particularly casino table card games in the wagering structure. There are a multitude of card games that are based on one or more decks of conventional playing cards. Among the most popular of these games is poker, wherein a player's fortunes are determined by a well-known hierarchy of card combinations. Card games that are variants of poker are also very popular, such as Let It Ride® stud poker, Caribbean Stud® poker, Three Card Poker® and the like. This is due, at least in part, to the basic nature of the underlying game itself, combining elements of both strategy and luck. Additionally, poker-variants allow an existing player-base to capitalize on their preexisting knowledge of a game and to apply that knowledge in novel settings. The two most popular forms of traditional poker are draw poker and stud poker.
In a conventional hand of draw poker, a single 52-card deck of shuffled playing cards is used. Each player begins a hand by contributing an initial or “ante” bet to a common pool or “pot”, the pot ultimately going to the owner of the single winning hand. The dealer then distributes five face-down cards to each player, the remaining cards in the deck being set aside for later use. Each player evaluates the cards that he or she has been dealt and each, in turn, is given an opportunity to discard one or more cards from the dealt hand. The dealer gives the player replacement cards for those that have been discarded by dealing additional cards face-down from the top of the deck. Following the deal, one or more rounds of betting take place, during which time each player may make an initial raise, a check wager, fold (drop-out), match a previous raise or raise a previous bet. These wagers are all added to the pot. The meanings of these wagering terms are well known to those skilled in the art and typical definitions of same may be found in, for example, Hoyle's Rules of Games, pp. 75-102, by Morehead and Mot-Smith, 1963, the disclosure of which is incorporated herein by reference. At the conclusion of the wagering rounds, the players display their hands and the holder of the highest ranking poker hand takes all of the money in the pot.
Stud poker is the most popular form of “open poker,” wherein each player is dealt some cards that are face-up and, hence, available for viewing by the other players. Stud poker comes in two varieties: 5-card and 7-card, the two being of approximately equal popularity. In five-card stud poker, the dealer gives each player a face-down (or “hole” card) and then a face-up card. Thus, at the start each player knows his own two cards and one card of each of his opponents. After the first two cards are dealt, a wagering round ensues, during which time each player contributes his or her wager to the pot. A typical description of the rules that govern this round might be found in, for example, Hoyle's Rules of Games, pp. 75-102, by Morehead and Mot-Smith, 1963, the disclosure of which is incorporated herein by reference. After the wagering round, another card is dealt face-up to each player. This is followed by another wagering round. Alternating dealing and wagering rounds continue until each player has a total of five cards: four face-up and a concealed hole card. After the final bets have been placed, each player who has not dropped out during the deal/wager rounds reveals his or her hole card. The owner of the highest ranking 5-card poker hand wins and takes whatever amount is in the pot. Only the player with the highest ranking hand wins.
Seven-card stud poker differs slightly from 5-card poker. First, in 7-card poker each player initially receives two cards face-down and one card face-up. A bidding round then ensues. The dealer then gives each player another face-up card, which is followed again by a bidding round. Deals (of one face-up card) and bids are alternated until each player has four face-up cards and two face-down cards. Finally, a third face-down card is dealt to each player (making a total of seven cards). This is followed by a last bidding round. The winner of the hand is the player who can form the highest ranking 5-card poker hand from his seven cards.
As is well known to those skilled in the art, five-card poker hands are ranked from “Royal Flush” (highest) to “High Card(s) in Hand” (lowest) according to the following ordering:
Hand
Description
Example
Royal Flush
The five top cards of a suit
A, K, Q, J, 10 (suited)
Straight Flush
Five cards in sequence in the
5, 6, 7, 8, 9 (suited)
same suit
Four of a Kind
Any four cards of the same rank
2, 2, 2, 2, J
Full House
Three of a kind and a pair
2, 2, 2, J, J
Flush
Five cards of the same suit
2, 4, 8, 10, A (suited)
Straight
Five cards in sequence
6, 7, 8, 9, 10
(unsuited)
Three of a
Three cards of the same rank
2, 2, 2, 9, J
Kind
Two Pair
Two cards of the same rank and
2, 2, Q, Q, A
two others of a different rank
(unsuited)
One Pair
Two cards of the same rank
9, 9, 5, 8, K
High Card(s)
Five unmatched cards
A, 9, 5, 3, 2,
in Hand
(unsuited)
In some variations of poker, the ace may also act as the lowest card in the deck to form a straight when used in a sequence like A, 2, 3, 4. Additionally, a “wild card”—often the “joker” card may be designated, so that a person who holds that card may declare its value to be that of any card in the deck, the presumption being that the declared card value will help that player form a better poker hand.
At its core, poker is a vehicle for gambling. Commonly the quantities wagered are monetary, but that is not strictly required and poker chips, matches, and other non-pecuniary tokens have been used in place of money to help the players determine who is winning without exposing them to financial loss. Of course, casinos are in the business of providing people with the opportunity to gamble and, given the popularity of poker among the general populous, it only stands to reason that casinos would desire to offer this game in some form or another to those who seek to play it. However, conventional-rules poker is not particularly well suited for use in a casino.
A casino that offers traditional poker to its clientele typically does so by providing a dealer and a room in which to play, but the casino's dealer does not actually participate in the game as a player. His or her function is just to distribute the cards and referee the game. The casino makes its money by taking some percent of all of the money wagered (the “rake”) or by leasing the room to the participants. The cost of the lease may be measured in time (e.g., a fixed amount per hour) or by a count of the number of hands played. Traditional poker games are not particularly favored by casinos because the casino does not make as much money acting as a landlord as it would if it were an active participant in the game. Similarly, from the standpoint of the gaming public, traditional poker has some disadvantages which have tended to make it less desirable as a casino game. First, traditional poker is readily available “at home,” e.g., at the Friday night poker session, and there is no particular need for most people to travel to a casino to play it. Second, when an individual wins at traditional poker it is at the expense of the other players/participants. Many people prefer to play against the more impersonal “house” (i.e., the casino) so that their winning hand does not necessarily result in a loss by a fellow player, who may be an acquaintance. Finally, traditional poker does not offer the excitement associated with “jackpot” type games. That is, a royal flush in traditional poker—as improbable as that card combination is—will result in winning only the amount in the pot and nothing more. Many players seek out games where there is some possibility of “winning big,” an option that is not available under conventional poker rules.
As a consequence of these disadvantages, casinos have introduced a variety of poker-type game variants to address the shortcomings discussed previously. One obvious advantage of these poker-type games from the casino's point of view is that the casino becomes an active participant in the game (as the house) and can, as a consequence, increase the revenue earned with the game. Additionally, these poker-type games are very attractive to many of the gambling public, and the mere fact that they are available in a particular casino has the potential to increase consumer traffic and revenue there.
A variety of innovative strategies have been employed to make poker-type games more appealing to casino gamblers. For example, many poker-variants are designed to let the players compete against the house, rather than against each other. In other cases, progressive betting has been utilized, wherein the player may increase his or her bet during the play of a hand. This makes the game more exciting to the player and potentially more profitable for the casino. Jackpots have been introduced, wherein certain card combinations in the player's hand result in an enhanced payout to that player. Finally, computer implementations of these games is always an attractive possibility, with video based casino games becoming increasingly popular. One such video implementation of a poker-type game is taught by Weingardt, U.S. Pat. No. 5,042,818. Of course, a natural next step is to offer these same video based casino games over the Internet, thereby making the games available to a potentially enormous audience. The most successful casino table poker games to date are Let It Ride® stud poker (as originally described in U.S. Pat. No. 5,288,081), Caribbean Stud Poker® (originally described in U.S. Pat. No. 4,836,533), and Three Card Poker® (as described in U.S. Pat. No. 6,237,916).
In most casinos, a game of blackjack begins by having each player place an initial wager. The blackjack dealer then distributes two cards face-down to each player and two cards—one face up and another face down—to him or herself. After the player has examined the two dealt cards and compared those cards with the face-up dealer's card, a number of options present themselves to the player. The player may “stand” (i.e., take no further cards), draw one or more additional cards in order to increase the numeric sum of the hand, double down (a form of progressive wagering), or split the two cards.
Additionally, if the dealer's face-up card is an ace, the player may elect to buy insurance against the possibility that the dealer has a blackjack. If, after the dealer's face-down card is revealed, the dealer does not have a blackjack, the player loses the amount that was paid as insurance (although he or she may go on to ultimately win that deal). If, on the other hand, the dealer has a blackjack, the player collects double the amount of insurance bought (but may still lose the amount of the original wager). The option of purchasing insurance is unique to blackjack type games and has not, heretofore, been available in poker-style games. The broad rules of blackjack are generally known to those skilled in the art and a fuller description may be found in the materials previously incorporated by reference.
In addition to novel games being introduced into casinos, novel betting formats have also been introduced. Side bets have always been common in wagering environments, but the use of side bets for jackpots and bonuses in casino table card games was believed to have been first practiced by David Sklansky in about 1982 in a public showing of Sklansky's Poker in Las Vegas, Nev. The play and/or betting structure of Caribbean Stud Poker® was modeled after that game. Blackjack has allowed surrender play at many tables, where half the original wager is withdrawn and the other half is forfeited to the house at the election of the player. U.S. Pat. No. 5,820,460 (Fulton) describes a method for playing a casino table card game wherein wagers are changed after some cards are viewed by the player. Let It Ride® stud poker advanced that theory significantly as described in U.S. Pat. No. 6,273,424, where specific segments of wagers could be withdrawn from an original wager that was made in multiple parts.
It is still beneficial to provide additional wagering formats and structures to add both interest to the game and better control over house retention and player awards.
The desired attributes of wagering games outlined above are in large measure provided by the method and apparatus for a wagering game in accordance with the present invention. The game is uncomplicated, exciting and provides the opportunity for players to make multiple wagers and choices regarding those wagers.
SUMMARY OF THE INVENTION
The wagering game of the present invention is played with a single, typical fifty-two card poker deck and broadly involves the generally well recognized and accepted set of rules, procedures and wager-resolving outcomes of five card poker. One embodiment of the game is a variation of Let it Ride® Stud Poker, as described in my co-pending application Ser. No. 10/286,440 filed Oct. 31, 2002 and Ser. No. 10/254,628 filed Sep. 24, 2002, both entitled Bet Withdrawal Casino Game With Wild Symbol, the content of both specifications hereby incorporated by reference.
The game method of the present invention comprises each player placing an initial, three or more part wager, and preferably a four-part wager (as opposed to the required three-part wager used in Let It Ride® stud poker) to participate in the game. Cards are dealt by a dealer. In one example, three cards are dealt face down to each player and two cards are dealt face down to the dealer. Players inspect or “sweat” their cards, and the dealer asks “take it or leave it?” or “Let It Ride®?” with regard to the first part of the initial bet. Players can choose to retrieve or remove from play the first part of their initial bet, or leave the first part in play or at risk, based on the value of the three cards in their hand. The dealer then turns over one of the dealer's cards and that card is considered a part of each player's hand. The dealer's query is repeated with regard to the second and third parts of the initial bet, except that withdrawal of the second part of the bet results in the house automatically claiming the third part of the wager. This step requires that two parts (the second part and the third part) of the four-part bets (usually equal parts) be considered at the same time of play. This interdependency between the second and third bets could alternatively exist between the first and second bets. Players can choose to retrieve or remove from play the second part and forfeit the third part of their initial bet or leave the second part and third part in play or at risk, based on the value of the four cards consisting of the three cards in the player's hand and the first exposed dealer's card. Players have no option with the fourth part of the bet, which is referred to as the contract wager, as it must remain in play through the conclusion of play of the game. Finally, all cards are shown and the payouts and collections are resolved according to the ranking of the poker hand of each player, i.e., the players are not playing against each other or the dealer.
Several variations in the game are contemplated by the present invention. For example, three wagers rather than four may be placed. The player has the option to withdraw his first bet. If he withdraws the first bet, the second bet is swept by the house. The third bet is the contract bet and cannot be removed by the player. Similarly, the player could place five bets, with the second and third, or third and fourth bets having the interdependency of that of the second and third bets in the first example of the invention. What is meant by “interdependency” for purposes of this disclosure is that when any bet, except the contract bet is withdrawn by the player, another bet is automatically forfeited to the house.
The game play could be similarly modified, allowing the players and dealer more or less cards. What is important to the invention is that the player receive partial information about his hand, and then be given at least one opportunity to withdraw a portion of his bet, resulting in an automatic forfeiture of another portion of this bet as a result of the decision to withdraw.
The pay table in this game (to be marketed as “Dakota Stud™” table card game) can be adjusted from the pay tables in Let It Ride® poker to reflect the change in betting/wagering structure. For example, to compensate for the required forfeit of the third wager part if the second wager part is withdrawn, the qualifying hand for a win may be lowered from the pair of 10's ordinarily required to win against the pay table in Let It Ride® stud poker. For example, the minimum winning hand may be any pair, a pair of 2's, 3's, 4's, 5's, 6's, 7's, 8's or 9's. Additionally, higher odds may be paid on higher ranked hands to make play of the game more attractive to players. The game may also be modified to provide the player with five cards and the dealer with two hole cards or common cards, with the best five-card poker hand playing against a pay table, or with the player being dealt four cards, and the dealer receiving three cards. This may be done with the dealer having one of the three cards exposed immediately before consideration of withdrawal of the first part of the wager, or with three cards provided face down. In the latter circumstance, the dealer's face down cards may be exposed one-at-a-time, or preferably two at one time and one card at another time in the betting/wagering sequence. Two cards may be exposed before consideration of withdrawal of the second (and third) parts of the wager, or first one card exposed at this stage and then two cards exposed at the end of play, after withdrawal of the second and third parts has been considered and exercised.
More specifically, in the preferred play of the game, the initial wager placed by each player comprises four equal parts and is made or placed before any cards are dealt. Each player is dealt three cards face down in the customary fashion. Two common cards are dealt face down in front of the dealer for use by all of the players. Each player will use the two common cards in front of the dealer in combination with his or her three cards to create a five-card hand. After all players have placed their four wagers/bets (and in an optional play of the game, a special bonus wager or jackpot wager for extra or extraordinary awards for high ranking hands against a pay table) and received and examined their cards, each is given the opportunity to retrieve one part (if equal wagers are placed, that is one-fourth) of the initial wager before the dealer reveals one of the two down cards previously placed in front of him. After all of the players have been queried and decided whether to withdraw the first part of their wager, the dealer turns one of the down cards face up. Each player now has the benefit of four cards, the three he or she is holding down plus the common card, and the dealer again gives each player the opportunity to retrieve further part(s) of the initial wager. In this case, with equal wagers, the player has the option of leaving the second and third parts in play or withdrawing the second part and forfeiting the third part before exposing the second common down card. After the second common down card is revealed, the players turn up the three cards they are holding thereby forming five card hands made up of the three cards dealt to each player and the two dealer cards. The dealer examines each of the players hands and determines what payout, if any, each player is entitled to receive according to that players' remaining wager and a preselected payout schedule. Payouts are made to players with winning hands and the losing wagers are collected. The cards are then reshuffled for the next hand. Where a separate side bet has been placed as a bonus or jackpot wager (against a pay table and/or against a progressive jackpot), that wager must also be resolved.
Apparatus is disclosed for playing the wagering game according to the method outlined above. A typical gaming table, with a playing surface, is modified to include specific areas that provide locations for placing the wagers and for displaying the common cards. A card shuffling machine such as that disclosed in U.S. Pat. No. 4,807,884 or other shuffling machines manufactured by Shuffle Master Gaming, Inc. of Las Vegas, Nev. for facilitating and speeding the play of the wagering game may be used. A display device may be associated with the apparatus for displaying game information, shuffle status, or other information relevant to the dealer, the players or the house.
The present invention provides an exciting and interesting wagering game. The wagering game is easy to learn, largely being based on five-card stud poker and the well known ranking of five card poker hands. The present invention provides a new variation of a well known wagering game, five card poker, and in particular Let It Ride® stud poker, which is made more interesting by providing the opportunity for players to make multiple wagers and decisions related to those wagers based on the progress of the game.
Still another aspect of the present invention is to provide a wagering game that is easy to learn, yet demands skill of players in making strategic decisions about whether to withdraw a portion of the bet. It is yet another aspect of the present invention to provide a unique, exciting card game for play in casinos or at home and on various media including casino tables, video poker machines, video lottery terminals or home computers. It is an advantage of the game of the present invention that wagering decisions are inherent in the game. The game enhances players' sense of participation and takes advantage of players' inclination to keep wagers at risk once placed. The interdependency of at least two bets further encourages players to let bets remain at risk.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the table layout and apparatus used in playing the wagering game of the present invention; and
FIG. 2 is a block diagram representing the flow of play in the game.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , the apparatus for the wagering game of the present invention includes a typical casino gambling or gaming table 10 . The table 10 has a curved side 12 for accommodating up to seven players and a straight side 14 for accommodating the dealer. The table 10 has a flat surface 16 covered with felt or other appropriate material. Although seven playing positions or locations 18 a-g for individual players are provided, it is not essential to the game that exactly seven persons play and as many as sixteen players may participate. For casino play, a maximum of seven players provides for a game that is easily manageable by the dealer and house, and one in which the individual players feel more involved. A house dealer position 20 , including an area suitable for displaying the dealer's cards 21 , is provided.
Each of the playing positions 18 a-g includes a wagering zone 22 , comprising four separate and distinct wagering or betting areas 22 a, b, c, d . A separate wagering area 22 e may be provided for placing of a bonus, jackpot (e.g., progressive jackpot) or other type of side bet wager. Each position 118 a-g also includes a card area 19 a-g for receiving and displaying cards dealt to the player occupying the position. The wagering areas 22 a, b, c, d are designed to receive appropriate wagering indicators or settling means such as chips or markers (not shown).
At one side of the dealer station 20 , the apparatus for practicing the method of the present invention may include a microprocessor or computer controlled shuffling machine 32 supported by a table extension 34 . The shuffling machine 32 may be of the type disclosed in U.S. Pat. No. 4,807,884, U.S. Pat. No.6,149,154 (both assigned to Shuffle Master, Inc.) or any other single deck or multideck shuffling apparatus manufactured by Shuffle Master Gaming, Inc., the disclosure of which patent is incorporated herein by reference. The shuffling machine 32 may include a dealing module for automatically and sequentially dealing cards and also may include a display means for displaying wager amounts, the identity of winning players, or other game related information.
Referring to the flow diagram of FIG. 2 , the initial step in playing the game of the present invention is preparing or shuffling a deck of cards, represented at block 40 , by activating the shuffling machine 32 or by hand-shuffling a deck to provide a shuffled deck. Typically, a standard 52 card deck with four different suits is used. Next, the players place the initial wager, block 42 , by putting equal amounts in each of the four betting areas 22 a, b, c, d . Two of the parts of this initial wager, the parts placed in wagering area 22 a and 22 b are retrievable at the option of the player. The third portion placed in area 22 c is a wager that is forfeited if the second wager at 22 b is withdrawn or stays at risk if the second portion remains at risk. The fourth part 22 d of the four part wager is a non-withdrawable bet. After the placing of the wager by each player, the cards are dealt, block 44 , preferably three cards being dealt down to each player and preferably two cards are dealt down in front of the dealer. The players inspect or “sweat” their cards in preparation for reaching decision block 46 . At decision block 46 , the players are queried by the dealer about whether the first part of the initial wager, the part placed in wagering area 22 a , should be left or whether the player wishes to withdraw that portion of the bet. Each player makes the decision at decision block 46 on the basis of the three cards forming the player's incomplete hand at this point. Once each player has been queried and has decided whether or not to let the first portion of the bet ride, and those bets the player chooses to retrieve or remove are physically removed from area 22 a and returned to the player, the dealer shows one of the down common cards, block 48 . Now, each player has four cards to consider, the three cards dealt to that player originally and the single common card showing on the table. Each player must then decide whether to let the second part of the initial wager ride or whether to withdraw it from the game. As noted, if the second part of the wager is withdrawn, the third part of the wager is forfeited and is collected by the house. After each player is queried and decides what to do with regard to the second part of the bet, and those bets to be withdrawn are physically removed from area 22 b and returned to the player, the dealer reveals the second common down card, as represented at block 52 . Each player now has a five-card hand comprised of the three cards each player was originally dealt plus the two revealed common cards. The fourth bet, the bet placed at wagering area 22 d , is a nonretrievable portion of the initial bet and the flow of the game proceeds to block 54 wherein the players show or reveal their three cards to the dealer. The dealer resolves each player's bet (which includes all four parts, the second, third and fourth part or only the fourth part, or the first and fourth part, depending on the player's choices during play of the hand) based on the five card hand at block 56 and determines what payout, if any, the player is entitled to receive according to the payout schedule at the particular gaming table or casino. Bets on non-winning hands are collected by the dealer or house. The hand is then over and the flow of the game returns to block 40 , preparing and shuffling the deck for a new hand.
The award or payoff is given for each of the optional bets that remain at risk at the end of the hand and for the nonwithdrawable part of the bet. A typical pay table would be as follows:
Pair, Sixes or Better
1-1 (even money)
Two Pairs
2-1
Three of a Kind
3-1
Straight
4-1
Flush
6-1
Full House
9-1
Four of a Kind
40-1
Straight Flush
100-1
Royal Flush
500-1
The method of the present invention is not limited to five card poker games, but may be applied or used in other appropriate games such as seven card poker, as described elsewhere herein. The method of the present invention does not require a shuffling machine 32 , dealing module 33 or a display means 36 . However, these facilitate and expedite the play of the game as well as add interest to the game. While the initial wager of the present invention is preferably comprised of four equal bets, the bets do not necessarily have to be equal. The interdependent bets, such as the second and third parts in the above example, should be equal, or the third part may be smaller than or greater than the second part. Similarly, the first, second, third and fourth parts may be of different values, but the fourth bet must be at least equal to a table minimum and may be required to be at least equal to or greater than any other wager part. The method of the present invention could also include the placement of a contract bet, and two additional bets. When the player receives partial information on his hand (for example, three of five cards), he can withdraw the first part of his bet, and the house sweeps the second part of his bet. The hand is completed (for example, by revealing one or more common cards or dealing one or more extra cards to the player), and all bets that remain up are resolved. The betting structure of the present invention could also include making a five or more part bet, with one part being the contract bet and any of the two remaining bets being interdependent. It is preferable to mandate that the next to last bet be the bet that the house can take back in the event any previously placed bet is taken back by the player. This methodology encourages players to keep their bets in play. For example, the player may place six equal bets in a seven card stud game. The player is dealt three cards and the dealer is dealt four cards, face down. The player can withdraw a first bet after he views his first three cards. The dealer reveals a first common card and then has the opportunity to withdraw bet # 2 . The dealer reveals the second community card and the player can withdraw bet # 3 . The dealer reveals the third community card and the player can withdraw bet # 4 . If he does, the house sweeps bet # 5 . The 6 th bet, remains at risk. It is not necessary to require the player to keep subsequent bets at risk if he chooses not to withdraw a portion or portions of his bet. All betting decisions are preferably made independent of prior betting decisions in a given round of play.
The game can also be different. For example, the players could receive their own cards instead of playing with a combination of community cards.
Or, the base game could be 21 , and the player can make up to six or more equal bets, one per card dealt. The player can withdraw a portion of his or her bet with each card played.
While equal bets are highly preferred for casino play, unequal bets may be offered in a casino or may be used in home play, if desired. The wagering game of the present invention might be played live in casinos with a dealer, or in casinos or homes in interactive electronic or video form with automatic coin or betting means receptacles and payout capability, wherein appropriate symbols for cards, wagers or score keeping would be displayed electronically. A “board-type game” suitable for home, club or casino use may also be provided for practicing the method of the present invention.
In combination with or separate from the play of Dakota Stud™ casino table poker, a new wagering structure resulting in different bonus structures may be used. The pure wagering structure described above, where the third part (or second part, in another example) of the wager is tied to the election made by the player on the separate part of the wager is itself novel. The use of that wagering structure in combination with certain pseudo-pooling payout outcomes at the table is a further advance in the structure of wagering and play at casino table card games.
An example of the additional wagering structure and alternative payout structures include the use of excess retention by the house because of the unique wagering structure described above in the four-part wager (e.g., retaining a pair of 10's or other rank higher than 6's, 7's, 8's, or 9's as the winning hand) or by providing the option of making a side bet to enter the additional award structure described below. Once the player is entered into the additional award structure (either automatically or with the optional or required side bet), the payout can be altered as follows. Those players that are entered into play of the additional award structure can participate in winning awards at the table, even where the awards occur in different hands, that is, hands of other players.
In present known table games with bonuses or jackpots with side wagers, only the player receiving the hand is paid on the achievement of the bonus hand of at least a predetermined rank. In some poker clubs, certain events are paid both to players at the table and to the winning player from a pool when certain unusual events occur. For example, house rake may be partially deposited in a pool account. When the event occurs, the pool is paid to the table where it occurs and the money in the pool is distributed proportionally. Such a situation would occur where, for example, the winning event in a pool was where a losing hand at a card table was at least a full house with at least three Aces and two 10's as the losing hand. The pool is distributed among the players and the sometimes the dealer at the table as, for example (70% to the winning hand, 10% to the losing hand and 20% to the remaining players at the table; or 70% to the winning hand, 15% to the second place hand, 20% to the remaining players at the table, and 5% to the dealer). The pool is a form of a progressive jackpot which is incremented according to discretionary rules of the poker club or casino. All players at the table share the pool winnings if they anted in the play of the hand where the winning event occurred. No distinct side wager or particular wagering element is required to enter into the chance to win the pool, which occurs with only a single specific event occurring, as described.
In the practice of the present invention, accruing a prize pool from the third (and/or other interdependent bet swept by the house) wager (automatically entering the player in the bonus event during the game) or preferably requiring a separate side wager to enter the bonus payout event is used to enable a player to enter the bonus event. The player is either required to place a side bet or has the option of placing a side bet to enter the bonus event. The bonus event is played against a pay table, whereby whenever any player at the table achieves a hand of predetermined rank, all players that are entered into the bonus event (either automatically or by placing the side bet) partakes of the bonus award for the predetermined hand. The rules may vary, so that a) only players that made the side bet wager can participate in the bonus, b) only players that made the side bet wager and remain in the game at the end of the hand can participate in the bonus, c) only players that made the side bet wager and have a qualifying hand can participate in the bonus, or d) only players that made the side bet wager and have a hand that beats the dealer's hand can participate in the bonus. The preferred method of play is a). Bonuses may be paid for only the highest hand, the top two hands, all winning hands or combinations thereof. The play of this bonus event with side bet can even be extended to include multiple tables. For example, certain progressive jackpot games link tables for the jackpot or bonus awards taken out of the jackpot pool. The tables can be linked by having players who had made the side bet wager at a distal table in the last hand before the bonus event was won at a proximal table. This is not a preferred embodiment (because of potential complexities in synchronization of play or debating when hands were played relative to distal side bets), but is within the skill of play and design. Additionally, the bonus may be paid either when any hand at the table achieves the predetermined hand rank, or only when a player that has made a side bet achieves a hand of the predetermined rank. The second format is preferred to stimulate more persons at the table to make the wager.
An aspect of this pay structure is to increase the frequency of bonus events at a table. With more players at a table, there are more hands per game at the table, and the hit frequency of bonus hands increases. Even though the actual size of individual awards per player decreases, the increased frequency improves the overall player acceptance of the game. For example, if there are six players at a table, the frequency of bonus hands statistically increases to six times what the frequency was with a single player at the table.
The payouts for each player will necessarily vary according to the number of players that are in the game and/or have made the side bonus bet. The various payouts on each hand vs. the number of players in one example is represented on the table layout as a matrix of payouts for the players and dealer to see. The house may require a minimum number of players to engage play of this side bet bonus event, primarily to limit the number of pay tables that must be displayed. It is also possible to have a display device (e.g., screen, monitor LED, liquid crystal display, plasma screen, etc.) that is fed by data from a computer or microprocessor or other image source to show the applicable or dynamic pay table for the number of players involved in the payout for the hands at any given point in time. For example, the display may show separate screen for 2 player, 3 player, 4 player, 5 player, 6 player and 7 player bonus events, each screen having different odds and payouts. Automated equipment indicating the number of wagers placed, the number of players entered, the rank of the hand, and other factors can be provided. For example, camera, scanners, digital readers, and software interpreting the data such as that provided in U.S. Pat. Nos. 6,313,871; 6,460,848; 6,126,166; 5,941,769; and the like could be used to assist in automating the reading of cards, ranks, wagers, and the number of players.
It is also possible for players to elect to play a “double bonus.” In this format, rather than a typical one dollar side bet being placed, two separate one dollar wagers or a single two dollar wager may be placed to enter the player in both an individual bonus payout event and the shared bonus event discussed above. Except where the bonus was a progressive bonus, this system could be highly attractive to players. The rules must be clear in the event that a progressive jackpot is used, so that it would be understood that a 100% jackpot win by a player with both side bets placed would win 50% of the total jackpot for him/herself, and the remaining 50% would be split among players in the bonus event, including the winning player. With a fixed bonus pay table, one of five players at a table with both side bets having been placed (the individual bonus and the shared bonus or group bonus wager) would receive a payment of the fixed amount for obtaining a predetermined rank hand and approximately one-fifth of the award for the group award on the ranked hand. For example, if the ranked hand were a Straight Flush with a $2,000 fixed award, the player with that hand would win $2,400—$2,000 for the individual bonus side bet and ⅕ th of $2,000 ($400) for the group bonus wager.
The side bets may be made on sensing systems or by placing tokens, chips or money on the table that remain on the table at appropriate locations until conclusion of the game. Typical sensing devices include coin drops, photo optical sensors, proximity detectors, cameras, scales, and the like.
The format of this game is particularly compatible with any poker-type games where bonus awards are provided from a pay table, such as Let It Ride™ stud poker, Three CardPoker®, Crazy 4 Poker™, 3-5-7™ Poker table game, and the like. Pay table structures are particularly useful as multiple winning hand combinations combined with the “table bonus” feature dramatically increase the hit frequency of winning bonus events.
The method of the present invention is also useful in games where progressive jackpots are used, alone or in combination with pay tables, such as with certain formats of Caribbean Stud™ poker. The wager could also be used in games where there are special bonuses given to players who obtain unique hands. For example, in Pai Gow poker, there may be special awards for perfect Pai Gow hands (e.g., 9, 8, 7, 5, 4, 3 and 2) or uniquely ranked hands (e.g., a front pair of aces and at least four-of a-kind on the rear hand). The payouts could be made to all players participating in the wager (e.g., on a proportional basis), rather than just to the player who obtains the hand. The bonus wager could also be doubled so that a player could receive both the individual award and the group award for the hand.
The present invention may be embodied in other specific forms without departing from the essential attributes thereof. It is desired that the embodiments described above may be considered in all respects as illustrative, not restrictive, reference being made to the appended claims to indicate the scope of the invention. | A method of playing a wagering card game for a number of player using standard playing cards having a standard rank and involving standard poker hand rankings comprises: each player placing at least four distinct wagering parts to participate in the game; dealing three cards to each player and at least two common cards, all of the at least two common cards being dealt face down; giving each player the chance to examine the cards received by that player and to withdraw at least a first part of the at least four distinct wagering parts wager based on the rank of the player's cards prior to one of the at least two common cards being dealt face down being exposed; showing the at least one common card, thereby providing at least a partial hand for each player, each player's at least a partial hand comprising the shown at least one common card and the cards each player was dealt; allowing each player to withdraw a second part of the at least four wagering parts and forfeiting a third part of the at least four wagering parts; showing at least one more common card to expose all common cards that had been dealt face down; and resolving each player's remaining wager based on the rank of that player's hand, which remaining wager was not withdrawn. | 0 |
This is a continuation of application Ser. No. 08/743,396 now U.S. Pat. No. 5,671,897, filed on Nov. 4, 1996, which is a continuation application of Ser. No. 08/638,403 now abandoned, filed Apr. 29, 1996; which is a continuation application of Ser. No. 08/441,498 now abandoned, filed May 15, 1995; which is a divisional application of Ser. No. 08/268,414 now abandoned, filed Jun. 29, 1994.
FIELD OF THE INVENTION
This invention relates to cores for core wound paper products, such as toilet tissue and paper towels, and more particularly to cores having improved physical properties and which reduce total raw material usage.
BACKGROUND OF THE INVENTION
Core wound paper products are in constant use in daily life. Particularly, toilet tissue and paper towels have become a staple in home and industry. Such products usually comprise a roll of a paper product spirally wrapped around a hollow core.
The hollow cores are typically made on a coremaking line and comprise inner and outer plies of paperboard superimposed in face-to-face relationship. Each ply of the paperboard is supplied to a coremaking mandril from a spool of raw material. When the two plies are fed to the coremaking mandril, they are typically helically wrapped in the same direction. During wrapping, the plies are adhered throughout to maintain the desired cylindrical configuration.
During converting, the cores are telescoped onto a mandril for subsequent processing--such as winding the paper product therearound. The mandrils are rapidly accelerated, which often causes the cores to burst. Core bursting is the phenomenon which describes a core rupturing on a mandril and disintegrating into strips of paperboard.
Core bursting cause two problems. First, there is a significant loss in efficiency as the mandril must be cleaned and restarted again and again until it runs smoothly and without core bursting occurrences. Secondly, each occurrence of core bursting causes material to be scrapped and increases manufacturing costs due to the excess of raw materials necessary to support each startup.
Of course, any time one desires to reduce material costs of the core, the first solution which comes to mind is to reducing the amount of materials used in the construction of the core. However, this "solution" has the drawback of further weakening the core, making it more susceptible to core bursting on the converting mandril--and the cycle repeats itself
If the core survives the converting mandril, there are other occasions where the properties of the core may cause it to be damaged before the core (and the paper product wound therearound) reach the consumer. For example, if the side to side (diametrical) crush strength of the core is not great enough, the core may collapse and cause the converting line to jam. In the converting line, cores are horizontally stacked several feet high in a converting bin. The converting bin has a trap door at the bottom which opens to feed the cores onto the line. The cores at the bottom of the converting bin must resist being crushed by the cores above while stacked in the bin and while fed into the line. If a core does not have sufficient side to side crush resistance, it will crush either blocking the cores from dumping into the converting line or will jam while in the line. In either occurrence, the converting line will incur a shutdown to clear the jam. Of course, the crushed cores must be discarded after they are cleared from the converting bin.
Assuming the core survives the converting mandril (and the balance of the line) without exploding the core is shipped with product wound therearound to a warehouse, where the cores are typically axially stacked in their cases. The cases of product wrapped cores are stacked several feet high in a warehouse and often are subjected to an axial compressive force in excess of 300 pounds. The cores at the bottom of the stacks must have sufficient crush strength to resist this axial compressive force, otherwise they will be crushed and the product may be too damaged to sell. Furthermore, if the cores at the bottom of the pallets are crushed, often gross deformation of these products occurs and the cases stacked near the top of the pallet fall over and are also damaged.
Accordingly, it is an object of this invention to reduce the material costs associated with making cores for core wound paper products. Furthermore, it is an object of this invention to increase the efficiency and speed at which the cores can be manufactured. Finally, it is an object of this invention to provide such cores having improved physical properties.
SUMMARY OF THE INVENTION
The invention is a multi-ply core for core wound paper products. In a preferred embodiment, the core comprises two plies, an inner ply and an outer ply. The two plies are joined together in face-to-face relationship and being helically wound together to form a hollow cylinder having helical ply gaps. The helical ply gaps are defined by the edges of the plies. The core has a thickness of at least two plies throughout its entire surface area.
The multi-ply core may have either the inner or outer ply overlap itself at a location registered with the ply gap formed by the other ply. Alternatively, a third ply having a width less than the width of the inner and outer plies may be provided and registered in an overlapping configuration with the ply gap of the inner ply or the outer ply.
BRIEF DESCRIPTION OF THE DRAWINGS
While the Specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawings in which like parts are given the same reference numeral. The ply gaps and extensions are shown exaggerated for clarity.
FIG. 1 is a perspective view of a core according to the prior art.
FIG. 1A is an end view of the core of FIG. 1.
FIGS. 2A-6 illustrate cores in a flat unfolded configuration, having the inner and outer plies shown separated for clarity.
FIG. 2A is a fragmentary end view of the core of FIG. 1A.
FIG. 2B is a fragmentary end view of an alternative embodiment of a core according to the prior art wherein the outer ply overlaps itself but not the ply gap of the inner ply.
FIG. 3 is a fragmentary end view of a core according to the present invention having the outer ply overlap itself at the ply gap of the inner ply.
FIG. 4 is a fragmentary end view of a core according to the present invention having the inner ply overlap itself at the ply gap of the outer ply.
FIG. 5 is a fragmentary end view of an alternative embodiment of a core according to the present invention having a reinforcing third ply applied to the ply gap of the outer ply.
FIG. 6 is a fragmentary end view of an alternative embodiment of a core according to the present invention having ply gaps offset 180° and overlaps at both the inner and outer ply gaps.
FIG. 7 is a graphical representation of the effects of this invention on converting efficiency.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 1A, a core 20' comprises an inner ply 22 and an outer ply 24 joined in face-to-face relationship to form a hollow cylinder having two opposed ends 30 defining a finite length. The plies 22, 24 are helically wound. As used herein helical windings include volute and spiral arrangements.
Each ply 22, 24 has a particular width 32 defined by two edges 34. The edges 34 of the inner ply 22 and outer ply 24 butt up to one another to form a ply gap 36I, 36O therebetween. The inner ply 22 is oriented towards a central longitudinal axis L--L of the core 20'. The outer ply 24 is oriented away from the longitudinal axis L--L of the core 20' and contacts the paper product when it is wound around the core 20'. As used herein "longitudinal" refers to the direction parallel the longitudinal axis L--L. The core 20' is typically elongate, having an axial dimension which is large relative to the diameter.
When toilet tissue is wound on the core 20', the resulting core wound paper product of toilet tissue typically has a diameter of about 4.00 to 5.00 inches and a length of about 4.50 inches between the ends 30. If a core 20' embodying the present invention is used for paper towels, the core wound paper product of paper towels typically has a diameter of about 4.00 to 6.25 inches and a length of about 11.0 inches for the embodiments described herein.
The core 20' may be made of two plies 22, 24 of a paperboard having any suitable combination of cellulosic fibers such as bleached krafts, sulfites, hardwoods, softwoods, and recycled fibers. The core 20' should exhibit uniform strength without weak spots. The core 20' may have a wall thickness of at least about 0.016 inches, and preferably has a thickness of at least about 0.028 inches. The core 20' should be free of objectionable odors, impurities or contaminants which may cause irritation to the skin.
The core 20' may be made of paperboard having a basis weight of about 19 to 42 pounds per 1,000 square feet, although cores 20' having a basis weight as high as 47 pounds per 1,000 square feet have been found to work well in the present invention. For the embodiments described herein, the material used for the core 20' should have a cross machine direction ring crush strength of at least about 50 pounds per inch, and preferably at least about 60 pounds per inch as measured according to TAPPI Standard T818 OM--87.
The two plies 22, 24 may be wrapped at an angle of about 31 to about 37 degrees, preferably about 34 degrees from the longitudinal direction. The inner and outer ply gaps 36I, 36O are typically offset from each other 180 degrees, as it is believed this configuration maximizes strength due to distributing the weak regions of the core 20' as far apart as possible. To maintain the face-to-face relationship of the inner and outer plies 22, 24, they may be adhered together with starch based dextrin adhesive, such as product number 13-1622 available from the National Starch & Chemical Company of Bridgewater, N.J. Generally a full coverage of adhesive at the interface between the inner and outer plies 22, 24 is preferred to minimize occurrences of core 20' failures due to the lack of full lamination of the plies 22, 24. It is important that the plies 22, 24 be adhesively joined at the overlap 42 to provide strength. The adhesive is conventionally applied to the inner face of the outer ply 24 because the outside of each ply 22, 24 must run over a tracking bar.
Referring to FIG. 2A, in one embodiment according to the prior art, the edges 34 of the inner and outer plies 22, 24 are offset from each other 180 degrees and are butted up against the opposing edge 34. This arrangement provides the disadvantage that at two locations throughout the core 20' only a single ply thickness 50 is present--even if the opposed edges 34 are in contact with each other. The two locations, of course, are the ply gaps 36I, 36O of the core 20'. It must be recognized the ply gaps 36I, 36O of the cores 20' are not individual points as indicated by the sectional views shown in the figures, but rather are two continuous lines which extend the entire longitudinal length of the core 20' between its opposed ends 30. This arrangement, while ostensibly minimizing material usage, suffers from various drawbacks. First, the resistance to core 20' rupture is minimized. More of such cores 20' will be scrapped during converting due to the greater chances of exploding or being crushed. Hence scrap increases and converting line efficiency decreases. Also, such a core 20' has relatively low values of side to side crush resistance and axial crush resistance.
One attempt in the prior art to improve this arrangement, illustrated in FIG. 2B, overlaps the edge 34 of the outside ply 24 upon itself for a short distance, typically 1/8 to 3/8 of an inch. However, the edge 34 at the overlap 42 of the outer ply 24 is offset from the ply gap 36O of the inner ply 22. Accordingly, this arrangement also has only a single ply thickness 50 at the ply gaps 36I, 36O. While such a core 20' may have slightly improved side to side and axial crush resistances, it also still suffers from the high scrap rates and converting line bursting inefficiencies discussed above.
As illustrated in FIG. 3, improvement may be recognized if the outer ply 24 not only overlaps itself, but also overlaps and extends beyond the ply gap 36I of the inner ply 22. This arrangement requires registration of the overlap 42 of one ply 22 or 24 with the ply gap 36O or 36I of the other ply 24 or 22 and has the advantage that the core 20' has a two-ply thickness 52 (which is adhesively bonded) throughout its entire surface area. Furthermore, there are two helical third plies of three-ply thickness 54, where the overlaps 42 occur. The overlap 42 of the outer ply 24 on itself should provide an extension 40 between the ply gap 36O of the outer plies 24 of at least 3/16 inches, and preferably at least 3/8 inches. The extension 40 is the circumferential distance from the edge 34 of one ply 22, 24 to the ply gap 36O, 36I of the other ply as measured along the overlap 42.
Furthermore, the edge 34 of the ply gap 36I of the inner ply 22 and the ply gap 36O of the outer ply 24 should be offset. This arrangement provides an extension 40 between the edge 34 of one ply 22, 24 and the ply gap 36O, 36I of the other ply 24, 22. A suitable configuration has an extension 40 between the inner ply 22 and outer ply 24 of approximately one-half of the amount of the overlap 42. An extension 40 in the amount of about 3/16 inches has been found particularly suitable for the embodiments described herein.
This arrangement may be accomplished by using an outer ply 24 having a greater width 32 between the edges 34 than does the inner ply 22. One arrangement which has been found suitable is an inner ply 22 with a width 32 of about 2.875 inches and an outer ply 24 with a width 32 of about 3.25 inches.
Referring to FIG. 4, in an alternative embodiment, the inner ply 22 overlaps itself in a manner similar to that described above with respect to the outer ply 24. This arrangement, while being more difficult to execute on the coremaking mandril, provides the advantage that the outwardly facing surface of the outer ply 24 is smoother and will not disrupt the winding process when the paper product is wound therearound and more readily accepts the adhesive to retain the paper product when winding begins. However, a disadvantage of this arrangement is that the overlap 42 of the inner ply 22 is more likely to catch at the exposed edge 34 when the core 20 is loaded onto the converting mandril.
Referring to FIG. 5, in a third embodiment, a separate ply 44 may be applied to overlie the outer ply gap 36O (as shown) or, hypothetically, a separate ply 44 may be applied to overlie the inner ply gap 36I (not shown). This arrangement provides a two-ply thickness 52 at the ply gap 36O or 36I to which the separate ply 44 was applied, and a three-ply thickness 54 outboard of the ply gap 36O or 36I.
Hypothetically, this arrangement would entail more difficulty in execution as three spools of the raw material are necessary, but has the advantage of two spools of the same width 32 to be used for the inner ply 22 and outer ply 24.
Referring to FIG. 6, in yet another embodiment, the edge 34 of the outer ply 24 may overlap its ply gap 36O a short distance. However, in this embodiment, the ply gap 36I of the inner ply 22 has an extension 40 from the ply gap 36O of the outer ply 24 sufficient that the overlap 42 of the outer ply 24 is not registered with the ply gap 36I of the inner ply 22. However, to compensate for this extension 40, in this embodiment, the edge 34 of the inner ply 22 overlaps the ply gap 36I of the inner ply 22. In this arrangement, two overlaps 42 are provided, one for each of the ply gaps 36I, 36O.
Cores 20 made according to the prior art (FIG. 2A) and according to the present invention (FIG. 3) and having various amounts of overlap 42 were made on The Procter & Gamble Company converting line at Mehoopany, Pa. Contrary to expectations founded in the prior art, it was found that less raw material was used per case of cores 20 produced when more material was used per core 20, when an overlap 42 of about 3/8 inch was utilized.
This outcome is illustrated in FIG. 7, wherein the side to side axis designates the amount of overlap 42, and the axial axis designates the number of cores 20 scrapped at startup when a new spool of raw material is inserted. As can be seen from FIG. 7, when more material is used for each core 20, fewer cores 20 (and hence less raw material) are scrapped.
The amount of additional material used per core 20 having a 3/8 inch overlap 42 is about 69.5 square inches or 69,500 square inches per 1,000 cores 20. However, each scrapped core 20 comprises about 1,140 square inches. On the average, 72 fewer cores 20, or 81,800 fewer square inches per 1,000 cores 20, are scrapped utilizing a core 20 according to FIG. 3. This yields a savings of 81,800 square inches per 1,000 cores 20. Therefore, the cores 20 according to the present invention save about 12,200 square inches of material per 1,000 cores 20. Each case of product has about 4.36 cores 20 therein. This invention saves about 53.4 square inches of core 20 material per case of product.
Furthermore, as illustrated by FIG. 7, the cores 20 according to the present invention exhibit improved converting efficiency. In FIG. 7, data points 1 and 7 are taken from actual plant data. Datum point 1 represents the cores 20 according to the prior art, which establish the baseline efficiency. Datum point 7 represents a core 20 having an overlap 42 of 0.375 inches and an improved efficiency of about 0.9 percent. A savings of 0.9 percent downtime translates to thousands of dollars in savings over the course of a year. Data points 2-6 and 8-9 are calculated from laboratory measurements. In the laboratory measurements a cone is inserted into the end 30 of a core 20 and compressed until failure occurs.
In the plant, the prior art cores 20' exhibited a loss of about 6.9 cores 20 out of every 1,000 cores 20 attempted to be manufactured. The losses were approximately equally distributed between cores 20 that were horizontally crushed at the bottom of the bins, cores 20 that jammed in the converting area, and cores 20 that exploded on the mandril. When cores 20 according to the present invention were tested on the converting line, the scrap rate dropped from 6.9 cores 20 per 1,000, to about 1.5 cores 20 per 1,000. This improved scrap rate alone represents a significant savings for a consumer product as inexpensive as toilet tissue.
In addition to the gains in converting efficiency illustrated by FIG. 7 recognized by utilizing cores 20 according to the present invention, there are also benefits in the core-making process. Particularly, core making according to the present invention yields an improvement of approximately 7 percent. This savings occurs because fewer cores 20 are scrapped during the core-making process. Cores 20 are scrapped during the core-making process because the plies 22, 24 delaminate near the ends 30 of the cores 20. Such delamination causes the cores 20 to jam during converting. Accordingly, such cores 20 must be sorted and scrapped during the core-making operation.
Utilizing cores 20 according to the present invention, approximately 7 percent fewer cores 20 were scrapped, compared to cores 20 according to the prior art. This results in an additional savings of 79,500 square inches of material per 1,000 cores 20, or 347 square inches of material per case of product.
However, additional savings were recognized from the present invention. The cores 20 that were crushed or exploded on the converting mandril caused a loss of almost 2 percent of the paper product because it must also be scrapped along with the cores 20. Utilizing the cores 20 according to the present invention reduced the scrap rate to less than 1 percent. This alone represents a tremendous financial savings and economizes natural resources when the phenomenal volume of toilet tissue produced during a year is considered.
Furthermore, yet another benefit recognized by the present invention is increased efficiency. Every time the converting mandril has to be cleared due to the paper product being crushed or the cores 20 exploding, downtime ensues. By reducing this downtime which is not reflected by FIG. 7, the product can be produced at higher efficiencies and lower cost.
Preferably, the overlap 42 for the embodiments described above with respect to FIGS. 3, 4, and 6 extend the entire longitudinal distance between the opposed ends 30 of the core 20. However, it will be recognized that at least a portion of the benefits can be achieved if the overlaps 42 do not traverse the entire longitudinal distance between the ends 30 of the core 20.
Similarly, with respect to the embodiment of FIG. 5, the separate ply 44 preferably traverses the entire distance between the opposed ends 30 of the core 20. However, it is to be recognized that again at least a portion of the benefits can be recognized with a ply 44 applied to only the central portion of the core 20 or to outboard portions of the core 20. It is to be recognized though that any embodiment which has longitudinal discontinuities, such as an overlap 42 or a ply 44, which is intermittently present in the core 20 will present manufacturing complexities. Additionally, converting efficiency improves and downtime decreases as fewer cores 20 are utilized during startup and raw material scrap decreases.
It will be apparent that many other variations, and permutations of the foregoing embodiments are feasible, all of which are within the scope of the appended claims. | A core for core wound paper products. The core is made by wrapping dual plies in a spiral pattern and adhering the plies together. The edge of one ply overlaps the ply gap of the other ply, preventing a single ply thickness from occurring anywhere on the core. Alternatively, the edge of each ply may overlap the ply gap of that respective ply. In yet another embodiment, the overlap may be formed by a separate ply applied to either ply. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for carrying rats to a processing site on air flow and an apparatus for trapping the rats.
2. Prior Art
The applicant proposed a technique to carry a rat by a carrier in a duct on air flow and move the trapped rat to a given position on air flow as disclosed in U.S. Pat. No. 4,566,218 and European Patent No. 0 159 634. In this technique, there are problems in that the carrier is consumed every time a rat is trapped and an accommodating space for accommodating many carriers is needed and inferior supply of the carriers is liable to occur.
SUMMARY OF THE INVENTION
It is therefore an abject of the invention to solve the problem of the prior art and to provide a method of carrying rats and an apparatus for trapping the rats capable of repeatedly utilizing a single carrier for trapping rats.
To achieve the above object, in the course of moving a carrier on air flow to thereby push a rat to a processing site when the rat in a duct is carried to the processing site, a rat alone is moved inside the processing site. Thereafter, air flow is generated to move the carrier backward while the carrier is held in the duct so as to be moved backward, so that the carrier is returned to an original position to prepare for a next trapping operation. Since the carrier can be repeatedly used, it is possible to dispense with many carriers and cases for accommodating the carriers therein and also possible to prevent the carriers from being inferiorly supplied one by one.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an apparatus for trapping rats according to the present invention;
FIG. 2 is a cross-sectional view of an accommodating portion;
FIG. 3 is an enlarged cross sectional view of a separation portion;
FIG. 4 is a plot diagram showing a control system; and
FIG. 5 is a flow chart showing an operation program.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an entire arrangement of a rat trapping apparatus 1. The rat trapping apparatus I is provided with a duct 4 for guiding and carrying a trapped rat 2 and a spherical carrier 3. An entry opening 5 is formed in the middle portion of the duct 4. A door 6 is positioned at the entry opening 5 and is closable by an operation unit 7. One or more heat sensitive entry sensors 8 are provided at the portion close to the entry opening 5 for detecting the rat; 2 which entered the duct 4. The carrier 3 is formed of a light and soft material and is spherical and it has a diameter which is slightly smaller than an inner diameter of the duct 4.
There is provided an accommodation portion 9 at one end of the duct 4 for holding the carrier 3 and it is connected to a suction port of a blower 10 for returning the carrier 3. The accommodation portion 9 comprises a T-shaped branch tube provided vertically as shown in FIG. 2 and it has an air valve 11 at one side of thereof. The air valve 11 is closable by an operation unit 12. A dish-shaped metal mesh 13 for holding the carrier 3 is provided inside the accommodation portion 9. A limit switch 14 is attached to the duct 4 at the portion close to an inlet of the accommodation portion 9.
A separation portion 15 is provided at the other end of the duct 4 for permitting the rat 2 alone to pass therethrough. The separation portion 15 comprises a T-shaped branch tube as shown in FIG. 3 and is vertically provided for acting gravity upon the rat 2 when the rat 2 is carried. An air valve 16 is provided at one side of the separation portion 15 and it is closable by an operation unit 17.
There are provided inside the separation portion 15 a throttle portion 18 having an effective diameter which is smaller than the carrier 3 for permitting the rat 2 alone to pass therethrough and a small diameter portion 19 which does not continue from the throttle portion 18. A photosensor type rat trap sensor 20 is attached to the inside of the separation portion 15 at the lower portion thereof. An effective opening area of the throttle portion 18 is set to be substantially the same as that of the entry opening 5. An area of an air inlet portion defined between the throttle portion 18 and the small diameter portion 19 is set to be substantially the same as that of the air valve 16.
A processing unit 21 is connected to the separation portion 15 at the lower portion thereof and at the position where the rat 2 passes therethrough. The processing unit 21 contains therein an inner box 22 and a gas injection/refrigerator unit 23, described later. The inner box 22 accommodates therein the trapped rat 2 and it can be taken out from the processing unit 21. The gas injection/refrigerator unit 23 is a combination of a suffocating gas injection unit for suffocating the trapped rat 2 or a refrigerator in which antifreeze solution is contained for freezing and killing the rat 2. It is a matter of course that the suffocating gas injection unit and the refrigerator as set forth above may be used instead of the gas injection/refrigerator unit 23.
To generate air flow in the separation portion 15 for carrying the carrier 3, namely, in a carrying direction, a suction port of a blower 24 is attached to the lower portion of the separation portion 15 or to the processing unit 21 at the state where the processing unit 21 is closed. A limit switch 25 is attached to the duct 4 at the inlet portion of the separation portion 15.
A control unit 26 is illustrated in FIG. 4. The control unit 26 is connected to the entry sensor 8, the limit switches 14, 25, the trap sensor 20 at its input side and it is also connected to the operation units 7, 12 and 17, the blowers 10 and 24, and the gas injection/refrigeration unit 23 at its output side. The control unit 26 executes a series of operation programs in response to an input signal, thereby operates the trap processing.
A series of operation programs are illustrated in FIG. 5.
When the rat 2 entered the duct 4 through the entry opening 5 when the door 6 is opened, the entry sensors 8 detect the presence of the rat 2 and issues a signal. In response to the signal from the entry sensors 8, the control unit 26 first drives the operation unit 7 to close the door 6, secondly drives the operation unit 12 to open the air valve 11 and thirdly rotates the motor of the blower 24 so that the blower 24 starts the suction operation. As a result, air flow in the carrying direction is generated inside the duct 4 so that the carrier 3 moves from the accommodation portion 9 to the separation portion 15 for pushing the rat 2 inside the duct 4 and moving the rat 2 toward the separation portion 15.
When the rat 2 and the carrier 3 passed by the limit switch 25, the control unit 26 drives the operation unit 17 of the separation portion 15 so that the air valve 16 is opened to introduce a fresh air from the outside thereinto. As a result, the air flow in the separation portion 15 at the upper side is weakened and the air flow at the lower side is relatively weakened. Consequently, the rat 2 in the duct 4 passes through the throttle portion 18 due to the air flow with assistance of gravity and it drops inside the inner box 22 of the processing unit 21 due to the strong air flow at the lower side of the separation portion 15. At the time when the rat 2 passed through the inside of the separation portion 15, the air valve 16 opens full to introduce the fresh air into the duct 4 so that the suction force of the air is reduced inside the duct 4. As a result, the carrier 3 can not pass through the throttle portion 18 but it is lightly held and stopped by the throttle portion 18.
The trap sensor 20 detects the dropping state of the rat 2 and it confirms that the rat 2 is trapped. Thereafter, the gas injection/refrigerator 23 is operated to thereby suffocate or refrigerate and kill the rat 2 inside the inner box 22.
After the trapping of the rat is confirmed, the control unit 26 stops the suction operation by the blower 24 and closes the air valve 11 and thereafter it operates the blower 10 so that the blower 10 starts the suction operation for generating another air flow to return the carrier 3 in its original position. As a result, the carrier 3 held by the throttle portion 18 is moved inside the duct 4 by another air flow which is opposite to the air flow generated by the blower 24 in its flowing direction and it is returned to its original position and accommodated inside the metal mesh 13 of the accommodation portion 9.
When the carrier 3 passes by the limit switch 14, the limit switch 14 detects the passage of the carrier 3 and issues a detection signal. In response to this detection signal, the control unit 26 stops the suction operation by the blower 10 and opens the door 6 upon confirmation of the returning of the carrier 3 to its original position so as to prepare for a next trapping operation and thereafter it completes a series of operations by closing the air valve 16.
According to the present invention, since the rat 2 alone enters the inside of the trapping apparatus 21 at the separation portion 15 after the carrier 3 moved the rat 2 and the carrier 3 is returned to an original position, the carrier 3 can be recycled, namely, it can be used repeatedly. As a result, there are following effects. Firstly, many carriers are not needed and cases for accommodating many carriers are not needed. Further, the rat trapping apparatus can be incorporated in a small space. Still furthermore, the rat trapping apparatus can be maintained with low cost since expendable supplies are reduced. | A method of carrying rats and an apparatus for trapping rats capable of solving problems of a prior art apparatus by repeatedly using a single carrier during the carriage of a rat. In the course of carrying a rat inside a duct toward a processing site, air flow is generated to move a carrier which pushes and moves the rat to the processing site but the carrier is held so as to be returned to its original position. At this time, another air flow is generate to return the carrier to its original position to prepare for a next trapping operation. | 0 |
BACKGROUND OF THE INVENTION
The invention concerns a method for manufacturing a woven fabric, in which weft thread loops are formed by at least one weft thread in at least one shed formed of warp threads, a device or apparatus on a loom for the performance of the method as well as a woven fabric manufactured according to the method.
A method for manufacturing a woven web has become known from Swiss Pat. No. 611,353, in which the weft thread is led from one side of the shed into this while forming a loop. On the other side of the shed, the weft thread loops are bound off by two auxiliary threads so that a very resistant fabric edge is obtained. This and similar methods, in which the weft thread is led in from one side, have the disadvantage that visibly different fabric edges are obtained.
SUMMARY OF THE INVENTION
It is an important object of the invention to create a method and a device on a loom for the manufacture of a woven fabric, which displays the advantage that two like fabric edges are obtained, which can no longer be distinguished optically.
The method of manufacturing a woven fabric according to the invention, in which weft thread loops are formed by at least one weft thread in at least one shed formed of warp threads, is manifested by the features that the weft thread is positioned to program for the weft introduction in warp direction within the warp width in the shed and before every beating of the reed is led out towards each shed side over the outermost warp thread while forming a loop extending in zig-zag shape, where it is bound off, retained, glued or fixed with itself or wit an auxiliary thread for the formation of the fabric edges.
The apparatus for the performance of the method contemplates that at least two weft introduction organs are arranged externally of the shed and engaging into the same, apart from the edge forming means arranged on a loom to each side of the fabric.
It is possible to lead the weft thread out first to the one side while forming a first loop and thereupon to lead it out to the other side while forming the second loop. This can take place with the arrangement of a weft thread introduction organ on each side of the shed. In that case, two fork-shaped needles can be used for pushing as well as also two hook-shaped needles for drawing. Advantageously, the weft thread is led out simultaneously to each side while forming two loops, for which in turn a hookshaped or a fork-shaped needle can be arranged on each shed side. Both weft thread introduction organs can also be present on the same shed side and together reach into the shed, wherein a fork-shaped needle forms the first loop while traversing the shed, while the hook-shaped needle forms the second loop on the return. When the weft thread is led in at the centre of the shed and a hook-shaped needle simultaneously reaches from each side into the shed only as far as the centre, wherein the loops are formed during the return of the needles, a very high weaving speed can be attained. Several threads can also be led in by an equipment controllable according to pattern, from which the weft thread can be selected as desired. Finally, it is also feasible to provide several sheds with the corresponding weft introduction organs.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a detail top plan view of a loom with the device according to the invention;
FIGS. 2 and 3 illustrate the same detail as in FIG. 1 with device variants.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the detail showing of the loom according to FIG. 1, only the parts essential for the understanding of the invention are illustrated purely schematically, all remaining parts being omitted to enhance the illustration of the drawings. A woven fabric 1 in the process of formation displays warp threads 2, which form part of a shed 3 continuing upwardly in the drawing. In the shed 3, the warp threads 2 extend between the webs 4 of a read 5. Arranged behind the read 5 is a thread guide 6, which serves to lead in a weft thread 7 positioned to program. A weft introduction organ in the form of a fork-shaped needle 8 and 9 is present on each side of the shed 3. An edge formation means for the binding-off in the form of a tongue needle 10 and 11 is likewise arranged on each side of the fabric 1.
During the weaving operation, the warp threads 2 raise and lower in known manner and alternately form a shed 3. In the centre of the warp threads 2, the weft thread 7 passes through a tooth gap between two webs 4 of the reed 5 into the working region of the shed 3. As illustrated in FIG. 1, the shed 5 has just executed its beating movement in known manner and completed the weft introduction; in that case, it has moved forwardly in arrow direction A towards the fabric beating edge 12, which is indicated by the webs 4 illustrated in dashed lines whereby the loops 13 and 15 last formed by the weft thread 7 have been anchored in the fabric 1, and has again returned into the setting with the webs 4 illustrated in solid lines.
The control of the fork-shaped needles 8 and 9 in arrow direction B and of the tongue needles 10 and 11 in arrow direction C likewise takes place in known manner. Starting from the setting shown in FIG. 1, the needle 9 now displaces into the shed 3 during the next weft introduction, where it catches the weft thread 7 by the fork in the centre and pushes it out beyond the outermost warp thread 2 while forming a weft thread loop 13. The tongue needle 10 now catches the weft thread loop 13 and binds it off with an auxiliary thread 14 in not illustrated, known manner. While the needle 9 returns without thread into its initial setting, the needle 8 displaces into the shed 3, catches the weft thread 7 by the fork and pushes it out on the other side over the outermost warp thread 2 while forming a weft thread loop 15. There, the weft thread loop 15 is caught by the tongue needle 11 and bound off with an auxiliary thread 16. After the needle 8 has returned into its initial setting, the reed advances and beats both the just formed weft thread loops 13 and 15 against the fabric beating edge 12, whereupon the described process repeats during the next weft introduction and both the next weft thread loops 13 and 15 are formed and brought into the fabric 1.
The use of two auxiliary threads for the formation of the fabric edges is not absolutely necessary, since the weft thread loops can also be bound off with only themselves. Yet, the use of, for example, differently coloured auxiliary threads permits interesting pattern possibilities for the fabric edges. Instead of binding off the weft thread loops, they can also be retained by suitable edge forming means or glued or fixed to the fabric by appropriate means until after the reed beating. Instead of leading the weft thread into the centre of the warp threads, it can also be led in between any two desired warp threads. When the weft thread is led in between any two desired warp threads, for which both the outermost on each side are excluded, then an interesting fabric binding is obtained. As is evident from the course of the weft thread at the places 21 to 28 in FIG. 1, the weft thread in the fabric passes both the warp threads, between which it was led in, in the following manner: crossed--not crossed above--crossed--not crossed below--crossed--not crossed above--crossed--not crossed below--etc.
In the variant according to FIG. 2, both weft introduction organs are mounted on the same shed side and they can be constructed as individual organs or as one-piece double organ. During the simultaneous traversing of the shed, the fork-shaped needle 9 again forms the weft thread loop 13, while the weft thread 7 during the return into the initial setting is caught by the needle 8, now constructed in hook shape, and the weft thread loop 15 is formed. After this loop has been taken over by the tongue needle 11 for binding off, a lifting organ 17 belonging to the weft introduction device lifts the weft thread 7 out of the hook of the needle 8 so that both the loops 13 and 15 can be beaten by the reed 5. As is likewise evident from FIG. 2, apart from the thread 7, a still further thread 7' is guided through the same tooth gap of the reed 5. In that case, the thread guides 6 and 6' are apart of an equipment controllable according to pattern so that the weft thread can selectably be chosen alternately from the threads 7 and 7', for example of different colours, while the not selected thread 7' is brought into the fabric as additional warp thread. Both threads can also be led in through other tooth gaps at different places. Also, the weft thread can be selected from more than two threads, which results in a greater multiplicity of patterning,
According to FIG. 3, both weft introduction organs are constructed as hook-shaped needles 8 and 9, which reach into the shed 3 simultaneously from each side beyond the centre, seize the weft thread 7 and during their return simultaneously form the weft thread loops 13 and 15. For lifing the thread out of the hooks of the needles 8 and 9 after the loops have been taken over by the tongue needles 10 and 11, a lifting organ 17 and 18 is here arranged on each side.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly, | Method and device on a loom for the manufacture of a woven fabric, wherein weft thread loops are formed by a weft thread in a shed formed of warp threads. Through feeding the weft thread in within the warp width and out to both sides over the outermost warp threads while forming loops, a woven fabric is obtained with like fabric edges which can no longer be distinguished optically. | 3 |
This application claims the benefit of GB Application No. 1218055.0 filed Oct. 9, 2012, GB Application No. 1316115.3 filed Sep. 10, 2013, and PCT/EP2013/071018 filed Oct. 9, 2013, International Publication No. WO 2014/056966 A1, and the amended sheets from the IPRP, which are hereby incorporated by reference in their entirety as if fully set forth herein.
The present invention relates to methods for applying surface coatings and is especially, but not exclusively, related to methods for depositing protective polymer coatings onto fabrics and the resultant coated fabrics.
The words fabric or fabrics as used in this application includes materials that are not woven as well as woven or knitted textiles, which may be manufactured into articles such as items of apparel for application in daily use, in industrial environments, in personal protective equipment (PPE), in sport and leisure environments and so on. Other articles into which fabrics may be manufactured as well are commodities, such as backpacks, umbrellas, tents, blinds, screens, canopies, tapestry, household textiles, sleeping bags etc. Fabrics are also utilised as filtration media articles for use, for example, in heating, ventilation or air conditioning (HVAC) systems or for use in exhaust filters, diesel filters, liquid filters, filtration media for medical applications and so on. Frequently, in HVAC applications, fabrics are not woven, knitted or otherwise formed into materials with a regular fibre structure or regular arrangement of the fibres. The methods and processes of this invention are applicable to all such fabrics.
BACKGROUND OF THE INVENTION
It is known to coat fabrics with coatings, e.g. polymer coatings, for the purpose of protecting the fabric from wear such as that experienced during everyday use or during repeated wash cycles.
Prior art methods of depositing the coatings describe polymerising fluorocarbon gas precursors such as tetrafluoromethane (CF 4 ), hexafluoroethane (C 2 F 6 ), hexafluoropropylene (C 3 F 6 ) or octafluoropropane (C 3 F 8 ) using plasma deposition techniques. Other precursor monomers such as fluorohydrocarbons, e.g. CF 3 H or C 2 F 4 H 2 or fluorocarbonethers such as CF 3 OCF 3 or long chain acrylates or methacrylates having perfluorocarbon chain lengths of eight carbons or more, such as 1H,1H,2H,2H—heptadecafluorodecyl acrylate (FC8), are also described in the prior art.
However, these particular classes of precursor molecules require high power plasma or pulsed plasma in order to initiate the polymerisation reaction. Moreover, such precursor molecules may also require high precursor gas flow rates and long deposition times in order to obtain an acceptable thickness of the polymer layer.
A problem that may arise when using high precursor gas flow rates and/or high power or pulsed plasma is that the resultant polymer coatings may have a non-uniform thickness. For instance, high power plasma causes monomers to fragment which can result in unpredictable deposition of the polymer and hence substandard coatings.
Another problem that may arise when utilising fluorocarbon gas precursor molecules such as those described above is that the subsequently formed polymer layer has limited hydrophobicity and oleophobicity. Typical contact angles for water that can be achieved with such coatings are maximum 90 to 100°. The resistance to oil is also limited to maximum level 3 to 4 according to ISO14419.
Another problem is that acrylates and methacrylates having perfluorocarbon chain lengths of eight carbons or more may contain significant levels of the hazardous, carcinogenic, chemical perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which have been the recent subject of investigation into adverse health effects of humans.
SUMMARY OF THE INVENTION
Another aspect is that for many of the prior art monomer precursors, gaseous and liquid, a carrier gas, e.g. an inert gas such as argon or helium, is used to generate the plasma. More, in prior art documents the ratio carrier gas/monomer indicates the use of more carrier gas than monomer precursor gas, e.g. ratios of 100:1 to 2:1.
It is a first non-exclusive aspect of the invention to provide a method for depositing a protective coating to a fabric, the method utilising low plasma power and/or low monomer flow rates and/or benign plasma conditions.
It is a second non-exclusive aspect to provide more resilient layers, layers with one or both of better in situ performance and increased uniformity, e.g. so as to which increase the lifespan of a fabric.
It is a third non-exclusive aspect to provide a coating for fabrics with high levels of hydrophobicity and/or oleophobicity, for instance so that items of apparel or commodities that are formed subsequently from the fabric are sufficiently water and/or oil proof. Because certain types of air filtration media are electrostatically charged it is desirable to provide coatings having high levels of hydrophobicity and/or oleophobicity in order to reduce discharge of electrets in case of contact with a discharging material, e.g. isopropanol, without adversely affecting the properties, e.g. filtration properties, of the fabric.
It is a fourth non-exclusive aspect to provide a safer, non-toxic protective coating for fabrics.
A first aspect of the present invention provides a method of coating a fabric, including a textile material, with a polymer coating, which method includes contacting a fabric with a monomer and subjecting the monomer to low power plasma polymerisation, wherein the monomer comprises the general formula (I):
C n F 2n+1 C m X 2m CR 1 Y—OCO—C(R 2 )═CH 2 (I)
wherein n is 2 to 6, m is 0 to 9, X and Y are H, F, Cl, Br or I, R 1 is H or alkyl or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.
Preferably, the method includes the step of coating the fabric as the fabric is passed by unwinding from a first roller on which the fabric is placed into the apparatus for coating it and being wound onto a second roller.
Preferably, the method includes the step of coating the fabric as the fabric is guided between a first roller and a second roller.
Preferably, the method includes the step of coating one or both surfaces of a sheet of fabric.
Before deposition of the coating, it might be advantageous to gas out (or out-gas) the textile and to apply an activation and/or cleaning step. By gassing out the textile, which is normally stored on a roll prior to coating, the base pressures that are achievable in a coating apparatus or plasma chamber are lower than without the gassing out (or outgassing), which leads to a better coating quality. The gassing out takes place during the pumping down by removing and pumping away all moisture present in or on the surface of the textile material. The time needed for gassing out depends on the type of polymers used to make the textile. Natural fibres, e.g. cotton, tend to have a higher rate of retention of water in comparison to synthetic fibres.
Preferably, the gassing out of the roll of textile is done as the textile is unwound, passed through the plasma zone and wound onto a second roller in a first processing step. Before starting the outgassing step, the plasma chamber containing the roll is pumped down to a pre-determined low base pressure. Once this base pressure is reached, the outgassing starts by unwinding the textile from the roll without turning on the power source to avoid the presence of plasma in the chamber. As the pump is continuously pumping, moisture and trapped gases such as oxygen, nitrogen, carbon dioxide, noble gases and the like, are removed from the textile and away from the plasma chamber as the fabric is unwound from one roller and passes through the plasma zone without a plasma being present to be wound onto a second roller.
Depending upon the nature of the fabric, more complete outgassing can be achieved by repeating the process of unrolling the fabric and rolling it back onto a second roller. This may be repeated several times, particularly in the cases of natural fibres such as cotton or wool which tend to have a greater rate of absorption and retention of moisture than the synthetic fabrics.
When after the outgassing step the pressure inside the chamber is below a set base pressure for pre-treatment or below a set base pressure for coating, the next step, respectively the pre-treatment or the coating, can be started. If the set base pressure for pre-treatment or coating has not been reached, a second outgassing step can be executed by rewinding the textile from the second roller through the plasma zone to the first roller, while the pumping is continued and no plasma is generated inside the plasma zone.
If required, a third, fourth, fifth, etc. outgassing step can be done in the same way as described above by winding the textile back and forth.
The main advantage of this unrolling and re-rolling method of gassing out is the fact that moisture and trapped gases are removed faster because when gassing out is done on a complete roll without unwinding but only by pumping down without unwinding, the moisture and trapped gases held or found in the layers of textile close to the core of the roll tend to need long pumping times to be removed compared to the times required if the textile is unrolled because, for example, in most cases the moisture in those inner layers of fabric on a complete roll is not sufficiently removed, even for very long pumping times.
Preferably, during the outgassing, the fabric runs at a speed from 1 to 30 m/min, for example 2 to 20 m/min, such as 3 m/min to 15 m/min, most preferably at approximately 5 to 10 m/min.
Preferably, the speed at which the second, third, fourth, etc. outgassing step takes place is equal to or higher than the speed of the first outgassing step. Whether the speed is increased or not depends upon a variety of factors such as the composition of the fabric, (whether it includes natural fibres such as cotton of wool or is a synthetic fibre such as a polymer or polymers, the thickness, the construction, etc.).
Preferably the tension at which the fabric is wound is equal to the tension at which the coating takes place.
With this improved way of gassing out, a larger amount of moisture and trapped gases is removed and it is also done in a reduced time, which is beneficial for both coating quality and total processing time.
A pre-treatment in the form of an activation and/or cleaning and/or etching step might be advantageous towards the adhesion and cross-linking of the polymer coating.
Adhesion of the polymer coating to the fabric is essential for ensuring good and durable coatings capable of withstanding repeated washing of plasma coated textiles. In most cases, textiles contain residues as a result of manufacture processes used to make the textile, e.g. dyeing, weaving, warping, even yarn spinning. When such a textile is coated with a polymer, a substantial part of the polymer coating binds with these residues, and during washing a portion of the residue(s) is removed together with the coating. A pre-treatment in the form of an activation and/or cleaning and/or etching step removes these residues and prepares the textile for better binding of the polymer coating, thereby increasing the durability of the coated textile, e.g. during washing.
Preferably, this pre-treatment is done using inert gases, such as argon, nitrogen or helium, but also more reactive gases might be used, e.g. hydrogen and oxygen and/or etching reagents such as CF 4 . The pre-treatment is performed with continuous wave plasma or pulsed wave plasma for short residence times in the plasma zone.
Preferably, the activation and/or cleaning and/or etching runs at a speed from 1 to 30 m/min, for example 2 to 20 m/min, such as 3 m/min to 15 m/min, most preferably at approximately 5 to 10 m/min.
Preferably the tension at which the fabric is wound is equal to the tension at which the coating takes place.
Preferably, when applied in continuous wave mode in a 9000 l chamber, the pre-treatment takes place at 25 to 10000 W, more preferably 50 to 9000 W, even more preferably at 100 to 8000 W, and further preferably 200 to 7500 W, and preferably still from 250 to 7000, 6750, 6500, 6250, 6000, 5750, 5550, 5250, 5000, 4750, 4500, 4250, 4000, 3750, 3500, 3250, 3000, 2900, 2800, 2750, 2700, 2600, 2500, 2400, 2300, 2250, 2200, 2100, 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, or 300 W.
Preferably, when applied in pulsed wave mode in a 9000 l chamber, the pre-treatment takes place at a peak power value of 25 to 10000 W, more preferably 50 to 9000 W, even more preferably at 100 to 8000 W, and further preferably at 200 to 7500 W, and preferably still at 250 to 7000, 6750, 6500, 6250, 6000, 5750, 5550, 5250, 5000, 4750, 4500, 4250, 4000, 3750, 3500, 3250, 3000, 2900, 2800, 2750, 2700, 2600, 2500, 2400, 2300, 2250, 2200, 2100, 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, or 300 W.
It will be appreciated that the power and power mode at which the pre-treatment is performed depends on the gas or gas mixture used, and/or on the dimensions of the chamber and/or the design, size and/or number of electrodes present in the chamber.
In a first embodiment, the total coating process comprises one single step, i.e. a coating step, whereby no gassing out and no pre-treatment is undertaken prior to coating the textile.
In another embodiment, the total coating process comprises three steps, each step including unwinding the textile, passing the textile through a plasma zone and winding up the textile, the steps including: a step for gassing out the textile; a pre-treatment step such as a plasma cleaning and/or activation and/or etching; and a coating step.
For the pre-treatment step, the winding up zone of the outgassing becomes the unwinding zone of the pre-treatment and the unwinding zone of the outgassing becomes the winding up zone of the pre-treatment. For the coating, the winding up zone of the pre-treatment becomes the unwinding zone of the coating and the unwinding zone of the pre-treatment becomes the winding up zone of the coating.
In a further embodiment, the total coating process comprises two steps, each step including unwinding the textile, passing it through the plasma zone and winding it up, the steps including: a step for combined gassing out and pre-treating (activating and/or cleaning and/or etching) the textile; and a coating step. For the combined gassing out and pre-treatment both processes take place at the same time.
For the coating step, the winding up zone of the first step becomes the unwinding zone of the coating and the unwinding zone of the first step becomes the winding up zone of the coating.
Alternatively, the method may include the step of coating the fabric with a polymer coating whilst the fabric, e.g. an article of apparel, is fixedly positioned inside the plasma chamber.
Preferably, R 1 is H, R 2 is H, and Y is H.
Preferably, m is 1 to 9.
Preferred examples of the monomer include acrylates and methacrylates having perfluorocarbon backbones comprising two to six carbon atoms, such as 1H,1H,2H,2H-Perfluorooctyl methacrylate or 1H,1H,2H,2H-Perfluorooctyl acrylate.
Preferably, the method includes the step of utilising the monomer to strike the plasma to form the deposited polymer coating. Advantageously, there is no need to utilise an additional gas to strike the plasma.
Preferably, the method includes the step of applying a polymer coating having a thickness of from 10 to 500 nm, more preferably of from 10 to 250 nm, even more preferably of from 20 to 150 nm, e.g. most preferably of from 30 to 100 nm, 40 to 100 nm, 40 to 90 nm. The layer may be less than 500 nm, for example, less than 450, 400, 350, 300, 250, 200, 150, 100 nm.
Preferably, the method comprises applying a polymer coating having a uniformity variation of less than 10%.
Preferably, the method includes applying a polymer coating having a uniformity variation of the contact angles for water of less than 100 and a uniformity variation of the oil repellency of less than 0.5 according to ISO14419.
In the current invention, superhydrophobic surfaces can be created with contact angles for water of more than 100°, say 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119 or 1200. The same coatings are superoleophobic with oil repellency levels above or above and including 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8 for example up to 6 according to ISO14419, say up to or up to and including 4, 4.5, 5, 5.5, 6, 6.5, 7 7.5, or 8.
Preferably, the method includes the step of depositing a polymer coating having a contact angle for water of 100° or more and/or an oil repellency level of 3, 4 or more according to ISO14419 in a residence time in the plasma zone of approximately 2 minutes or less.
Preferably, the method includes the step of depositing a polymer layer having a thickness of approximately 30 nm in a residence time in the plasma zone of approximately 1 minute or less.
Preferably, the method includes the step of depositing a polymer layer having a thickness of approximately 50 nm in a residence time in the plasma zone of approximately 2 minutes or less.
The method may include drawing a fixed flow of monomer into a plasma chamber using a monomer vapour supply system. A throttle valve in between a pump and the plasma chamber may adapt the pumping volume to achieve the required process pressure inside the plasma chamber.
Preferably the throttle valve is closed by more than 90% (i.e. to reduce the effective cross section in the supply conduit to 10% of its maximum value) in order to reduce the flow through the chamber and to allow the monomer to become evenly distributed throughout the chamber.
Once the monomer vapour pressure has stabilized in the chamber the plasma is activated by switching on one or more radiofrequency electrodes.
Alternatively, the method may include introducing the monomer into the plasma chamber in a first flow direction; and switching the flow to a second direction after a predetermined time, for example from 10 to 300 seconds, for example from 30 to 240, 40 to 180 seconds, for example less than 180, 170, 160, 150, 140, 130, 120, 110, 100, 90, 80, 70, 60, 50, 40, 30 or 20 seconds to a second flow direction.
Preferably, further switching of the monomer flow direction may be executed, e.g. flow may be switched back to the first flow direction or to one or more further flow directions.
Preferably, monomer may enter the plasma chamber in the first flow direction for between 20 to 80% of a single process time or 30 to 70% of the time or 40 to 60% of the time or 50% of the time.
Preferably, the monomer may enter the plasma chamber in the second flow direction for between 20 to 80% of a single process time or 30 to 70% of the time or 40 to 60% of the time or 50% of the time.
Preferably, the first and second flow directions flow in substantially opposite directions. For instance, during a process, monomer may be introduced into the plasma chamber via walls or inlets which are substantially opposite to each another.
Advantages of the inventive method include, but are not limited to, one or more of allowing highly reactive classes of monomer to polymerise under low power continuous wave conditions; generating a benign plasma; adaptable design of the plasma zone and number of electrodes to optimize the process speed for improved implementation in production environments; providing a means for accurately controlling the temperature to avoid undesirable temperature gradients; adaptable tension on load cells and variable driving of the rollers for optimal winding of the material; adaptable design of the unwinding and winding up zone depending on the dimensions and weight of the roll of textile material to be coated.
Advantages of the inventive polymer coating include, but are not limited to, improved hydro- and oleophobic properties of the coated textile; improved functionality of the coated textile; improved adhesion; improved durability of the coated textile and maintained electrostatic charge in time and in case of contact with discharging liquids such as isopropanol for electrostatically charged filtration textiles, e.g. electrets.
A second aspect of the present invention provides a fabric, e.g. a textile material, having a polymer coating obtainable by contacting a fabric with a monomer and subjecting the monomer to low power plasma polymerisation, wherein the monomer comprises the general formula (I), and wherein n is 2 to 6, m is 0 to 9, X and Y are H, F, Cl, Br or I, R 1 is H or alkyl, e.g. —CH 3 , or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl, e.g. —CH 3 or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.
Preferably, the fabric is a sheet of fabric, e.g. wound to a roll.
Preferably, the fabric is one of a woven, nonwoven, knitted, film, foil or membrane fabric.
Woven, nonwoven and knitted fabrics may have smooth surfaces or textured surfaces, in the cases of a pile weave or a pile knit for example.
Preferably the fabric comprises a synthetic material, a natural material or a blend.
Examples of materials include but are not limited to:
Synthetic: polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), polystyrene (PS), polyphenylene sulfide (PPS), polyacrylonitrile (PAN), polyurethane (PUR), polyurea, polytetrafluoroethylene (PTFE) and expanded polytetrafluoroethylene (ePTFE), polyester (PES)—such as polyethylene terephthalate (PET), recycled PET and polybutylene terephthalate (PBT), polyamide (PA)—such as PA6, PA66, and PA12, polyaramide, elastane (polyurethane-polyurea copolymer). Natural and man-made: cotton, cellulose, cellulose acetate, silk, wool, etc. Blends: cotton/PES 50:50, PES/carbon 99:1, recycled PES/elastane 92:8, etc. Woven and knitted fabrics may have a thickness of from 50 μm to 5 mm. Nonwoven fabrics may have a thickness of from 5 μm to 5 mm. Film or foil fabrics may have a thickness of from 20 μm to 1 mm.
Preferably, the polymer coating has a thickness of from 10 to 500 nm, e.g. from 10 to 250 nm, e.g. from 30 to 100 nm, e.g. from 40 to 90 nm.
Preferably, the polymer coating comprises superhydrophobic and/or superoleophobic properties. Preferably, the superhydrophobic polymer coating has a contact angle for water of 100° or more, say 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119 or 1200°. Preferably, the superoleophobic polymer coating comprises an oil repellency level above or above and including 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8, for example up to 6 according to ISO14419, say up to or up to and including 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or 8.
In a third aspect, the invention provides for the use of a monomer to form a polymer coating on a fabric, e.g. a textile material, when the monomer is brought into contact with the fabric and the monomer is subjected to low power plasma polymerisation, wherein the monomer comprises the general formula (I), and wherein n is 2 to 6, m is 0 to 9, X and Y are H, F, Cl, Br or I, R 1 is H or alkyl, e.g. —CH 3 , or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl, e.g. —CH 3 or a substituted alkyl, e.g. an at least partially halo-substituted alkyl.
In a further aspect, the invention provides a plasma chamber for coating a sheet of fabric, e.g. a textile material, with a polymer layer, the plasma chamber comprising a plurality of electrode layers arranged successively within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or at least two adjacent electrode layers are ground electrode layers.
In another aspect of the present invention, there is provided a plasma chamber for coating a sheet of fabric, such as a textile material, with a polymer layer, the plasma chamber having a plurality of electrode layers each having a generally planar or plate like form arranged successively within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or ground electrode layers.
Preferably, the at least two adjacent electrode layers are radiofrequency electrode layers.
Preferably, the outer pair of electrode layers are ground electrode layers.
In another aspect of the present invention, there is provided a plasma chamber having at least two pairs of electrode layers, and wherein the outer pair of electrode layers are either ground electrode layers or radiofrequency electrode layers.
Preferably, the plasma chamber comprises a pair of radiofrequency electrode layers and a pair of ground electrode layers, e.g. having the arrangement M/RF/RF/M or RF/M/M/RF, where ‘M’ denotes a ground electrode, ‘RF’ denotes a radiofrequency electrode, and wherein ‘/’ denotes the positions where the fabric passes between the electrode layers.
Preferably, the plasma chamber comprises further pairs of radiofrequency or ground electrode layers, e.g. having the arrangement RF/M/RF/RF/M/RF or M/RF/M/M/RF/M or M/RF/M/RF/RF/M/RF/M or RF/M/RF/M/M/RF/M/RF or RF/M/RF/M/RF/RF/M/RF/M/RF or M/RF/M/RF/M/M/RF/M/RF/M or M/RF/M/RF/M/RF/RF/M/RF/M/RF/M or RF/M/RF/M/RF/M/M/RF/M/RF/M/RF and so on.
In an alternative embodiment, the plasma chamber may comprise a first electrode set and a second electrode set, the first and second electrode sets being arranged either side of a passage for receiving a fabric.
Preferably, one or both of the first and second electrode sets comprise an inner electrode layer and a pair of outer electrode layers.
Preferably, the inner electrode layer is a radiofrequency electrode and the outer electrode layers are ground electrodes, e.g. having the arrangement M*RF*M/M*RF*M or M*RF*M/M*RF*M/M*RF*M and so on.
Alternatively, the inner electrode layer may be a ground electrode and the outer electrode layers may be radiofrequency electrodes, e.g. having the arrangement RF*M*RF/RF*M*RF or RF*M*RF/RF*M*RF/RF*M*RF and so on.
Preferably, the plasma chamber may include further electrode sets, for example third, fourth, fifth and sixth electrode sets and so on. For example when adding a third electrode set, e.g. M*RF*M/M*RF*M/M*RF*M, the fabric is coated on each side in two passes.
In all embodiments of the invention, where the electrode layer is of the radiofrequency type, the electrode layer may also include heat regulating means, e.g. a hollow portion such as a tube for receiving a heat regulator fluid.
Where the electrode layer is of the ground type, the electrode layer need not comprise a heat regulating means. Thus, electrode layers of this type may simply comprise a planar plate, mesh or other configuration suitable for generating plasma when arranged adjacent to a radiofrequency electrode layer.
The electrode layers are preferably of a planar or plate form. One advantage of such a configuration is that the generated plasma is substantially even across the surface of the electrode set. Consequently, the rate of polymerisation of monomer onto the substrate is the same at any given point on the substrate resulting in increased uniformity and so on.
Preferably, the heat regulating means comprises tubing which follows a path which curves upon itself by approximately 1800 at regular intervals to provide an electrode that is substantially planar in dimension.
Preferably, the heat regulating means comprises a diameter of from approximately 2.5 to 100 mm, more preferably from approximately 5 to 50 mm, even more preferably from approximately 5 to 30 mm, say up to 25, 20 or 15 mm, for example 10 mm.
Preferably, the heat regulating means has a wall thickness of from approximately 0.1 to 10 mm, more preferably from approximately 0.25 to 5 mm, even more preferably from approximately 0.25 to 2.5 mm, say 1.5 mm.
Preferably, the distance between the heat regulating means before and after the curve is between 1 and 10 times the diameter of the heat regulating means, say around 3 to 8, for example 5 times the diameter of the heat regulating means.
Preferably, the heat regulating means comprises a conductive material such as a metal, e.g. aluminium, stainless steel or copper. Other suitable conductive materials may be envisaged.
Preferably, the or each radiofrequency electrode generates a high frequency electric field at frequencies of from 20 kHz to 2.45 GHz, more preferably of from 40 kHz to 13.56 MHz, with 13.56 MHz being preferred.
Preferably, the plasma chamber further comprises locating and/or securing means such as one or more connecting plates and/or the chamber walls for locating each electrode or each electrode set at a desired location with the plasma chamber.
Preferably, the locating and/or securing means is removable from the plasma chamber, e.g. the locating and/or securing means is slidably removable from the plasma chamber.
Preferably, the plasma chamber comprises one or more inlets for introducing a monomer to the plasma chamber.
Preferably, each inlet feeds monomer into a monomer distribution system that distributes the monomer evenly across the chamber. For example, the monomer inlet may feed into a manifold which feeds the chamber.
Preferably the evaporated monomer is able to strike the plasma and thereby substantially obviates the need to use an inert gas, such as helium, nitrogen or argon, as a carrier gas.
However, Applicant found that in some cases the addition of a small amount of carrier gas leads to better stability of the plasma inside the plasma chamber, thereby providing a more uniform thickness of the coating layer. The ratio of carrier gas to monomer is preferably equal to or less than 1:4.
Preferably the carrier gas is an inert gas such as helium or argon.
Preferably the carrier gas and the monomer are mixed together before entering the process chamber, to provide an improved mixture of the carrier gas and the monomer prior to processing.
The apparatus also includes a monomer vapour supply system. Monomer is vaporized in a controlled fashion. Controlled quantities of this vapour are fed into the plasma chamber preferably through a temperature controlled supply line.
Preferably, the monomer is vaporized at a temperature in the range of 50° C. to 180° C., more preferably in the range of 100° C. to 150° C., the optimum temperature being dependent on the physical characteristics of the monomer. At least part of the supply line may be temperature controlled according to a ramped (either upwards or downwards) temperature profile. The temperature profile will typically have a low end which is at a higher temperature than the point where the monomer is vaporized towards the end of the supply line. In the vacuum chamber the monomer will expand and the required temperatures to prevent condensation in the vacuum chamber and downstream to the pump will typically be much lower than the temperatures of the supply line.
In those situations where small amounts of carrier gas are used, the carrier gas can be delivered from a gas bottle, a tank or reservoir. Its flow rate is regulated by a mass flow controller. After passing the mass flow controller, the carrier gas is fed into the monomer supply line, with the monomer already having passed a flow controller in order to have established a stable monomer flow and a stable carrier gas flow.
It is preferable that a minimum distance of a few mm, more preferably 10 to 100 mm, for example 10 to 90 mm, say less than 80, 70, 60 or 50 mm, most preferably 15 to 50 mm, is maintained between the electrodes and the surface of the fabric to be coated.
Preferably, the plasma chamber also includes a plurality of rollers for guiding a sheet of fabric, in use, between each electrode layer.
Preferably, the rollers are heated to avoid the presence of cold spots where the monomer could condense. Preferably the rollers are heated from room temperature of approximately 20 to 85° C., more preferably from 25 to 70° C., for example 30 to 60° C. Preferably the rollers are heated by water, oil or other liquids or combinations thereof, most preferably water. Preferably the rollers are provided with a temperature control means to regulate the temperature to avoid significant temperature differentials.
Preferably the rollers can be divided in two categories: load cells and normal rollers. For rigid textile materials, such as thick films or foils, the rollers do not need to be driven individually. It is sufficient for the winding up roller to be driven at a certain speed, and all other rollers will start rolling because of the winding up movement.
For more fragile materials, such as apparel textile and filtration materials, most or all rollers are driven individually to avoid damage of the fabric or material or a rupture of the sheet of textile material due to excessive tensions. Preferably, for the most fragile materials, e.g. membranes or thin open structured nonwovens, the rollers are all driven individually and can be fine-tuned individually or as a group e.g. to optimise the processing of fragile textile materials.
Preferably the plasma chamber has one or more load cells that can be calibrated once a predetermined low base pressure is reached and prior to the first processing step and before any unwinding or winding of the fabric on the rolls, e.g. prior to outgassing, or prior to the gas inlet and prior to turning on the electromagnetic field for a pre-treatment, or prior to the gas inlet and prior to turning on the electromagnetic field for the coating step, whichever comes first.
The load cells are not driven but provide a certain tension on the sheet of fabric to be coated. The tension needs to be selected according to the material type. For more fragile materials, and certainly for the most fragile materials, the applicant found that for each individual coating run after closing the machine and pumping down to base pressure, a calibration of all load cells improves the winding and coating quality.
Preferably prior to each individual coating run, the load cells are calibrated once the base pressure is reached and prior to the first processing step.
Preferably, during the coating process, the system runs at a speed of 0.1 m/min up to 20 m/min, for example 0.5 m/min to 15 m/min, such as 1 m/min to 10 m/min, say less than 9, 8, 7, 6 m/min, most preferably 1 to 5 m/min.
Preferably, the tension at which the fabric is wound is 0.2 to 250 kg (2 to 2500 N), more preferably 0.5 to 100 kg (5 to 1000 N), for example 1 to 50 kg (10 to 500 N), such as 1.5 to 25 kg (15 to 250 N), such as 1.5 to 10 kg (15 to 100 N).
Preferably, for rolls with limited outer diameter, weight and width, the unwinding zone and the winding up zone are positioned at the same side of the plasma chamber, wherein the unwinding starts in the lower part of the winding zone and the winding up takes place in the upper part.
Preferably, for rolls that are heavy, and/or have a large outer diameter and/or that are wide, e.g. 2 m wide, the unwinding and winding up take place at different sides of the plasma chamber, e.g. the unwinding at the left side and the winding up at the right side.
In a further aspect, the invention provides a method for coating a sheet of fabric, e.g. a textile material, with a polymer layer, the method comprising the steps of providing a plasma chamber having a plurality of electrode layers arranged successively within the plasma chamber, wherein at least two adjacent electrode layers are radiofrequency electrode layers or ground electrode layers; and guiding a sheet of fabric between said electrode layers.
Preferably, the method includes the step of regulating the temperature of each radiofrequency electrode layer, e.g. from approximately 5 to 200° C.
Preferably, the method includes the step of regulating the temperature of each radiofrequency electrode layer from approximately 20 to 90° C., more preferably from approximately 25 to 60° C., even more preferably from approximately 30 to 40° C.
Preferably, the step of regulating the temperature of each radiofrequency electrode layer comprises feeding a heat regulating means with a fluid such as a liquid such as water, oil or other liquids or combinations thereof.
Preferably, the method includes the step of controlling the temperature of the plasma chamber, e.g. to avoid temperature differentials within the chamber, and to avoid cold spots where the process gas can condense. For instance, the door, and some or each wall(s) of the plasma chamber may be provided with temperature control means.
Preferably, the temperature control means maintains the temperature from room temperature of approximately 20 to 70° C., more preferably from between 30 and 50° C.
Preferably, also the pump, the liquid monomer supply and all connections between those items and the plasma chamber are temperature controlled as well to avoid cold spots where the process gas or gases can condense.
Preferably, the method comprises the step of applying power across the radiofrequency electrodes via one or more connecting plates.
The power for the plasma may be applied in either low power continuous wave mode or pulsed wave mode.
Preferably, when applied in continuous wave mode in a 9000 l chamber, the applied power is approximately 5 to 5000 W, more preferably approximately 10 to 4000 W, even more preferably approximately, say 25 to 3500 W, even further preferably, for example 30 to 3000 W, preferably still, for example 40 to 2500 W, and even further preferably from 50 to 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 175, 150, 125, 100, 90, 80, 75, 70, or 60 W.
Preferably, when applied in pulsed wave mode in a 9000 l chamber, the applied power is approximately 5 to 5000 W, more preferably approximately 25 to 4000 W, even more preferably approximately 50 to 3500 W, preferably, for example 75 to 3000 W, preferably still, for example 100 to 2500 W, and even further preferably from 150 to 2000, 1900, 1800, 1750, 1700, 1600, 1500, 1400, 1300, 1250, 1200, 1100, 1000, 950, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, or 175 W.
When applied in pulsed power mode, the pulse repetition frequency may be from 100 Hz to 10 kHz having a duty cycle from approximately 0.05 to 50%, with the optimum parameters being dependent on the monomer used.
Although the preferred applied power might seem to be high, those skilled in the art will understand that a large plasma chamber, such as one of 9000 liter capacity, will include more and larger radiofrequency electrodes compared to machines in which small sheets of textile are coated instead of rolls. As a consequence the power is increased to form a uniform and stable plasma. But, compared to prior art gaseous precursor monomers, the inventive coating is deposited at low power. Prior art coatings deposited using gaseous precursors require an applied power of 5000 W or more, up to 10000 W and even up to 15000 W, depending on the dimensions and the number of electrodes.
Preferably, the radiofrequency electrode or electrodes generate a high frequency electric field at frequencies of from 20 kHz to 2.45 GHz, more preferably of from 40 kHz to 13.56 MHz, with 13.56 MHz being preferred.
Preferably, the step of guiding a sheet of fabric between said electrode layers involves the use of a plurality of rollers.
As used herein, the term “adjacent electrode layers” is intended to refer to a pair of electrode layers, whereby one of the pair is disposed, in use, on one side of a sheet of fabric and the other of the pair is disposed on the obverse side of the sheet of fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more readily understood, it will now be described by way of example only and with reference to the accompanying drawings, in which:
FIG. 1 shows a schematic representation of a roll-to-roll plasma deposition apparatus;
FIG. 2 shows a first electrode arrangement according to the prior art;
FIG. 3 shows a second electrode arrangement according to the prior art;
FIG. 4 shows a first electrode arrangement according to the present invention;
FIG. 5 shows a second electrode arrangement according to the present invention;
FIG. 6 shows a third electrode arrangement according to the present invention;
FIG. 7 shows a fourth electrode arrangement according to the present invention; and
FIG. 8 shows plan (a), side (b) and end (c) views of a radiofrequency electrode.
FIG. 9 is a graph showing results of water absorption in an uncoated material after one minute, one hour and twenty-four hours drip-out.
FIG. 10 shows oil repellency as a number of washing cycles.
FIG. 11 shows spray test results related to numbers of washing cycle.
FIG. 12 shows oil repellency with and without pretreatment compared to numbers of wash cycles.
FIG. 13 shows spray test results from a number of washing cycles.
FIG. 14 shows oil repellency in a function of numbers of Martindale abrasion cycles.
FIG. 15 shows spray test results in a function of numbers of Martindale abrasion cycles.
DETAILED DESCRIPTION
Referring first to FIG. 1 a roll-to-roll plasma deposition apparatus, indicated generally at 1 , will now be described. The apparatus 1 comprises a plasma chamber 10 , a first compartment 12 and a second compartment 14 . The first 12 and second 14 compartments are the unwinding and winding up compartments, arranged at both sides of the plasma chamber. These compartments are known to those skilled in the art and will not be described in any further detail.
The plasma chamber 10 comprises an array of electrode layers RF, M, the arrangement of which will be described in detail further below with reference to FIG. 4 . The plasma chamber 10 further comprises a series of upper and lower rollers 101 , 102 and load cells for guiding a sheet of textile material 16 between the electrode layers RF, M from a first roll 120 mounted in the first compartment 12 to a second roll 140 mounted in the second compartment 14 .
Schematic diagrams of electrode layer arrangements according to the prior art are shown in FIGS. 2 and 3 . The most basic arrangement is shown in FIG. 2 in which a radiofrequency electrode layer and a ground electrode layer are arranged in a side-by-side relationship. This arrangement may be symbolized as M/RF, where ‘M’ denotes a ground electrode, ‘RF’ denotes a radiofrequency electrode, and ‘/’ denotes the space in which the textile material 16 passes. Upper 101 and lower 102 rollers are arranged to guide a sheet of the textile material 16 from one roll 120 to another roll 140 . In use, and when an electromagnetic field is applied to the radiofrequency electrode layer RF, plasma is struck between the radiofrequency electrode layer RF and the ground electrode layer M. Such plasma is known as primary plasma. When monomer is present in the plasma chamber 10 this results in a polymer coating being applied to a surface of the sheet of textile material 16 that is facing the radiofrequency electrode layer RF, resulting in a sheet of textile material 16 having a uniform polymer coating applied to a single surface thereof.
FIG. 3 shows a further arrangement in which additional radiofrequency electrode layers RF and ground electrode layers M are arranged alternately in a side-by-side relationship. This arrangement may be symbolized as M/RF/M/RF/M. Again, primary plasma is struck between a radiofrequency electrode layer RF and a ground electrode layer M such that a polymer coating is applied to a surface of the sheet of textile material 16 that is facing the radiofrequency electrode layer RF. The sheet of textile material 16 makes four passes and on each pass the same side of the textile material 16 facing the radiofrequency electrode layer RF is coated, resulting in a sheet of textile material 16 having a uniform polymer coating applied to a single surface thereof.
In a first embodiment of the invention the electrode arrangement comprises ten electrode layers arranged in sequence as shown in FIG. 4 . This arrangement may be symbolized as M/RF/M/RF/M/M/RF/M/RF/M (this represents the arrangement as shown in FIG. 1 ). In use, and when an electromagnetic field is applied to the radiofrequency electrode layers, plasma is struck between the electrode layers. A primary plasma is struck between a radiofrequency electrode layer RF and a ground electrode layer M. Therefore, whilst it is clear that the sheet of textile material 16 makes nine passes between the electrode layers, only the first and last four passes are through primary plasma zones.
Accordingly, during the first four passes monomer is polymerised onto a first side of the sheet of textile material 16 whilst during the last four passes monomer is polymerised onto the obverse side of sheet of textile material 16 , resulting in a sheet of textile material 16 having a uniform polymer coating applied to each surface thereof. During the fifth pass an insignificant quantity to no monomer is deposited onto the sheet of textile material 16 .
FIG. 5 shows a second simplified embodiment of the invention in which the electrode arrangement comprises four electrode layers arranged in sequence. This arrangement may be symbolized as M/RF/RF/M. In use, and when an electromagnetic field is applied to the radiofrequency electrode layer, plasma is struck between the electrode layers. A primary plasma is struck between a radiofrequency electrode layer RF and a ground electrode layer M. Therefore, whilst it is clear that the sheet of textile material 16 makes three passes between the electrode layers, only the first and third passes are through primary plasma zones. Accordingly, during the first pass monomer is polymerised onto a first side of the sheet of textile material 16 whilst during the third pass monomer is polymerised onto the obverse side of the sheet of textile material 16 , resulting in a sheet of textile material 16 having a uniform polymer coating applied to each surface thereof. During the second pass an insignificant quantity to no monomer is deposited onto the sheet of textile material 16 .
In a third embodiment the electrode layers may be arranged as follows: RF/M/M/RF. Similarly, when an electromagnetic field is applied to the radiofrequency electrode layers, plasma is struck between the electrode layers. A primary plasma is struck between a radiofrequency electrode layer and a ground electrode layer. Therefore, whilst it is clear that the sheet of textile material 16 makes three passes between the electrode layers, only the first and third passes are through primary plasma zones. Accordingly, during the first pass monomer is polymerised onto a first side of the sheet of textile material 16 whilst during the third pass monomer is polymerised onto the obverse side of the sheet of textile material 16 , resulting in a sheet of textile material 16 having a uniform polymer coating applied to each surface thereof. During the second pass an insignificant quantity to no monomer is deposited onto the sheet of textile material 16 .
The applicant has surprisingly discovered that the polymer coating has greater uniformity, as found when measurements were made in testing e.g. in contact angles for water and/or greater uniformity in oil repellency, when the ground electrode layers are placed at the outer positions as described in the first and second embodiments.
In order to coat each side of the fabric the applicant has discovered that it is important to have a pair of identical electrode layers side-by-side in the series. For instance a pair of ground electrode layers, as described in the first or third embodiments, or a pair of radiofrequency electrode layers, as described in the second embodiment. This inventive arrangement results in the switching of polymer deposition from one side of the sheet of textile material 16 to another.
In further embodiments additional arrangements may be envisaged. For instance, RF/M/RF/RF/M/RF or M/RF/M/M/RF/M. In these embodiments it is clear that the sheet of textile material 16 makes five passes between the electrode layers: the first, second, fourth and fifth passes being through primary plasma zones. Accordingly, during the first and second passes monomer is polymerised onto a first side of the sheet of textile material 16 whilst during the fourth and fifth passes monomer is polymerised onto the obverse side of the sheet of textile material 16 , resulting in a sheet of textile material 16 having a uniform polymer coating applied to each surface thereof. During the third pass insignificant to no monomer is deposited onto the sheet of textile material 16 .
Similarly, even further embodiments are envisaged having additional electrode layers incorporated into the sequence, e.g. M/RF/M/RF/RF/M/RF/M or RF/M/RF/M/M/RF/M/RF or RF/M/RF/M/RF/RF/M/RF/M/RF or M/RF/M/RF/M/M/RF/M/RF/M or M/RF/M/RF/M/RF/RF/M/RF/M/RF/M or RF/M/RF/M/RF/M/M/RF/M/RF/M/RF and so on. As the number of electrode layers increases in the series so does the number of passes through a primary plasma zone. Accordingly, it is possible to control the thickness of the resultant polymer layer by increasing or decreasing the number of electrode layers in the sequence. Also, by increasing the number of electrode layers in the sequence it is possible to increase the speed within which the sheet of textile material 16 passes through the plasma chamber 10 without compromising on the quality of the polymer layer.
In a further embodiment shown in FIG. 6 the electrode layers are arranged as follows: M*RF*M/M*RF*M, where ‘RF’ denotes a radiofrequency electrode layer, ‘M’ denotes a ground electrode layer, ‘*’ denotes a primary plasma zone and ‘/’ denotes the space in which the fabric passes. In this embodiment the plasma chamber 10 comprises a first electrode set (M*RF*M) and a second electrode set (M*RF*M), wherein the first and second electrode sets comprise electrode layers and wherein each electrode set comprises two ground electrode layers M and a single radiofrequency electrode layer RF. In this embodiment it is clear that the sheet of textile material 16 makes a single pass between the electrode sets (M*RF*M).
Although we neither wish nor intend to be bound by any particular theory, we understand that the plasma created in between electrode sets (M*RF*M) of this embodiment of the invention cannot be described as either a pure primary or as a pure secondary plasma. Rather, the inventors consider that the electrode sets (M*RF*M) create a new hybrid form of plasma which is strong enough to start and maintain a polymerisation reaction at very low power, but which at the same time is benign enough not to break down the reactive monomers. Accordingly, during the first pass monomer is polymerised onto first and second sides of the sheet of textile material 16 , resulting in a sheet of textile material 16 having a uniform polymer coating applied to each surface thereof.
The processing speeds may be increased by adding further electrode sets (M*RF*M) to the plasma chamber 10 , for example third, fourth, fifth and sixth electrode sets (M*RF*M) and so on. For example when adding a third electrode set (M*RF*M), the sheet of textile material 16 is coated on both sides in two passes, e.g. M*RF*M/M*RF*M/M*RF*M or RF*M*RF/RF*M*RF/RF*M*RF. FIG. 7 shows an example of an electrode arrangement having six electrode sets (M*RF*M) arranged in sequence. In this design, contrary to FIG. 1 , the unwinding and the winding up take place in the same area at the same side of the plasma chamber.
FIG. 8 shows a radiofrequency electrode layer RF in plan (a), side (b) and end (c) views. The radiofrequency electrode layer RF comprises a generally planar body formed from folded tubing 21 . The tubing 21 may comprise a plurality of sections which are joined together by connectors 27 . The tubing 21 is typically formed of a conductive metallic material such as aluminium, stainless steel or copper. The tubing 21 is hollow to allow for a temperature regulation fluid to be passed through the electrode layer RF to regulate the plasma at a predetermined temperature. The tubing 21 comprises a series of bends 22 formed at regular intervals along the tubing length. The tubing 21 curves back on itself at each bend 22 by approximately 180°. The tubing 21 has a diameter of approximately 10 mm and a wall thickness of approximately 2 mm. The distance between the tubing 21 before and after each bend 22 is approximately 5 times the diameter of the tubing 21 .
The tubing 21 is curved at each end so as to provide distal portions 25 , 26 which are substantially orthogonal to the planar body. The distal portions 25 , 26 may be connected to a fluid supply or egress line (not shown). Alternatively, the distal portions 25 , 26 may be connected to the distal portions of adjacent or nearby electrode layers.
The radiofrequency electrode layer RF further comprises a pair of connecting plates 23 , 24 attached to the front and to the rear of the electrode layer 20 adjacent to the bends 22 . The connecting plates 23 , 24 provide both a means for attaching the radiofrequency electrode layer RF to the inside of the vacuum chamber 11 and electrical contacts for applying a load thereto.
A ground electrode layer M (not shown in detail) typically comprises a planar sheet of aluminium.
An example sequence of depositing a polymer coating to a roll of fabric is as follows:
1. A roll of fabric 120 to be treated is mounted in a first compartment 12 of the apparatus 1 ; 2. The free end of the fabric 16 is fed (manually or automatically) through the rollers 101 , 102 within the plasma chamber 10 and then secured to an empty roll 140 in a second compartment 14 ; 3. The plasma chamber 10 is closed and the electrodes, which are mounted on the moving part of the machine, are slid in between the guiding rolls (and thus in between the textile); 4. The plasma chamber 10 is sealed and pumped down to the required predetermined base pressure; 5. The load cells are calibrated for optimal processing; 6. Gas inlet valve is opened and the evaporated liquid monomer is fed into the plasma chamber 10 in a controlled manner at a controlled rate; 7. An electromagnetic field is applied to the radiofrequency electrode layers RF and a low power continuous wave plasma is generated; 8. Power is applied to the rollers 101 , 102 of the apparatus 1 in order to unwind fabric 16 from first roll 120 , and wind it onto a second roll 140 , during which time it passes between the electrode layers RF, M or sets of electrode layers M*RF*M, RF*M*RF where a polymer coating is deposited to each side of the fabric 16 before being wound onto second roll 140 ; 9. Once all of the fabric 16 has had a polymer coating applied thereto, the electromagnetic field is turned off and the plasma chamber 10 is ventilated to atmospheric pressure.
A second example sequence of depositing a polymer coating to a roll of fabric, e.g. in a 9000 l chamber, is as follows:
1. A roll of fabric 120 to be treated is mounted in a first compartment 12 of the apparatus 1 ; 2. The free end of the fabric 16 is fed (manually or automatically) through the rollers 101 , 102 within the plasma chamber 10 and then secured to an empty roll 140 in a second compartment 14 ; 3. The plasma chamber 10 is closed and the guiding rolls and all the textile (on roll in the unwinding area, the free end of the fabric mounted on a core in the winding up area, and the textile guided through the guiding rolls), which are mounted on the moving part of the machine, are slid in between the electrodes; 4. The plasma chamber 10 is sealed and pumped down to a predetermined base pressure required for outgassing and pre-treatment; 5. The load cells are calibrated for optimal processing; 6. The gas inlet valve is opened and the inert gas for the pre-treatment, e.g. cleaning and/or activation and/or etching, which is combined with further gassing out of the textile prior to coating, is fed into the plasma chamber 10 ; 7. An electromagnetic field is applied to the radiofrequency electrode layers RF and a plasma is generated; this plasma may be either a continuous wave plasma or a pulsed wave plasma, the choice of plasma mode being dependent upon the required power level and determined to be optimum for the pre-treatment gas or gases used and/or for the size and design of the plasma equipment and/or for a particular textile being used; 8. Power is applied to the rollers 101 , 102 of the apparatus 1 in order to unwind fabric 16 from first roll 120 , and wind it onto a second roll 140 , during which time it passes between the electrode layers RF, M or sets of electrode layers M*RF*M, RF*M*RF where moisture is removed from fabric 16 and where each side of the fabric 16 is pre-treated before being wound onto second roll 140 ; 9. Once all of the fabric 16 has been gassed out and pre-treated, the electromagnetic field is turned off and the plasma chamber 10 is pumped to the required lower base pressure for polymer layer deposition; 10. Gas inlet valve is opened and the evaporated liquid monomer is fed into the plasma chamber 10 in a controlled manner at a controlled rate; 11. An electromagnetic field is applied to the radiofrequency electrode layers RF and a low power plasma is generated; this plasma may be either a continuous wave plasma or a pulsed wave plasma, the choice of plasma mode being dependent upon the power level needed and determined to be optimum for a particular monomer being used to treat the material being treated and/or for the size and/or the design of the plasma equipment and/or for a particular textile being used; 12. Power is applied to the rollers 101 , 102 of the apparatus 1 and fabric 16 is unwound from roll 140 , passes between the electrode layers RF, M or sets of electrode layers M*RF*M, RF*M*RF where a polymer coating is deposited to each side of the fabric 16 before being wound onto roll 120 ; 13. Once all of the fabric 16 has had a polymer coating applied thereto, the electromagnetic field is turned off and the plasma chamber 10 is ventilated to atmospheric pressure.
Example 1
An experiment was carried out on small rolls of a textile for use as a filtration media before scaling up to production level. The textile comprised a nonwoven synthetic material comprising polymer fibres. The roll was 1000 m long and 1.1 m wide.
The process parameters are presented in Tables 1 and 2.
TABLE 1
Parameter
Value
Liquid Monomer Supply
(LMS)
Temperature canister
130-150° C.
Temperature LMS
140-150° C.
Plasma Zone
Length of plasma zone
6 m
Treatment speed
2 m/min
Tension
1.5 kg (15N)
Temperature walls
40-50° C.
Electrodes & Generator
Electrode configuration
M/RF/M/RF/RF/M/RF/M
Plasma type
Primary
Power
100-500 W
Frequency
13.56 MHz
Frequency mode
cw
Temperature RF electrode
30-35° C.
Monomer
1H,1H,2H,2H-Perfluorooctyl acrylate
Flow
40-100 sccm
Pressure
Base pressure
10-50 mTorr
Work pressure
20-80 mTorr
Residence time in plasma
3 minutes
zone
Oleophobicity Level
5
(ISO 14419-2010)
TABLE 2
Parameter
Value
Liquid Monomer Supply
(LMS)
Temperature canister
130-150° C.
Temperature LMS
140-150° C.
Plasma Zone
Length of plasma zone
6 m
Treatment speed
2 m/min
Tension
1.5 kg (15N)
Temperature walls
40-50° C.
Electrodes & Generator
Electrode configuration
M/RF/M/RF/RF/M/RF/M
Plasma type
Primary
Power
500-1000 W
Frequency
13.56 MHz
Frequency mode
pulsed (10 2 -10 4 Hz; duty cycle 0.1-20%)
Temperature RF electrode
30-35° C.
Monomer
1H,1H,2H,2H-Perfluorooctyl methacrylate
Flow
40-100 sccm
Pressure
Base pressure
10-50 mTorr
Work pressure
20-80 mTorr
Residence time in plasma
3 minutes
zone
Oleophobicity Level
3
(ISO 14419-2010)
The resultant coated textile according to Table 1 demonstrated good hydro- and oleophobic properties as well as efficient filtration so it was decided to scale up the process.
The resulting hydro- and oleophobic properties of the textiles coated with the process according to Table 2 are lower than from the coated textiles according to Table 1. However, it is decided to scale up this process as well.
Example 2
The processes of example 1 were increased in scale. The textile material was the same as that of example 1. The roll was 10000 m long and 1.1 m wide.
The process parameters are presented in Tables 3 and 4.
TABLE 3
Parameter
Value
Liquid Monomer Supply
(LMS)
Temperature canister
130-150° C.
Temperature LMS
140-150° C.
Plasma Zone
Length of plasma zone
12 m
Treatment speed
4 m/min
Tension
1.5 kg (15N)
Temperature walls
40-50° C.
Electrodes & Generator
Electrode configuration
M/RF/M/RF/M/RF/RF/M/RF/M/RF/M
Plasma type
Primary
Power
200-800 W
Frequency
13.56 MHz
Frequency mode
cw
Temperature RF electrode
30-35° C.
Monomer
1H,1H,2H,2H-Perfluorooctyl acrylate
Flow
50-120 sccm
Pressure
Base pressure
30-50 mTorr
Work pressure
70-90 mTorr
Residence time in plasma
3 minutes
zone
Oleophobicity Level
5
(ISO 14419-2010)
TABLE 4
Parameter
Value
Liquid Monomer Supply
(LMS)
Temperature canister
130-150° C.
Temperature LMS
140-150° C.
Plasma Zone
Length of plasma zone
12 m
Treatment speed
4 m/min
Tension
1.5 kg (15N)
Temperature walls
40-50° C.
Electrodes & Generator
Electrode configuration
M/RF/M/RF/M/RF/RF/M/RF/M/RF/M
Plasma type
Primary
Power
700-1200 W
Frequency
13.56 MHz
Frequency mode
pulsed (10 2 -10 4 Hz; duty cycle 0.1-20%)
Temperature RF electrode
30-35° C.
Monomer
1H,1H,2H,2H-Perfluorooctyl methacrylate
Flow
50-120 sccm
Pressure
Base pressure
30-50 mTorr
Work pressure
70-90 mTorr
Residence time in plasma
3 minutes
zone
Oleophobicity Level
3
(ISO 14419-2010)
The resultant coated textile according to Table 3 demonstrated good hydro- and oleophobic properties as well as efficient filtration. The resulting hydro- and oleophobic properties of the textiles coated with the process according to Table 4 are lower than from the coated textiles according to Table 3.
Results
Oil Repellency
Examples 1 and 2 show that low power continuous wave plasma polymerisation processes provide a better performance than pulsed wave plasma polymerisation processes. This is demonstrated by the oil repellency which is tested according to ISO 14419.
The results are presented in Table 5, and show that the oil repellency for continuous wave coatings of A4 sheets is higher than for pulsed wave coatings, the effect being more pronounced for short treatment times, e.g. 2 minutes.
TABLE 5 Oil repellency for continuous wave and pulsed wave Deposition mode Treatment time (min) Oil repellency Continuous wave (cw) 2 minutes L 6 Pulsed 2 minutes L 3 Continuous wave (cw) 5 minutes L 6 Pulsed 5 minutes L 4
Filtration Efficiency
The filtration efficiency for standard filtration media and filtration media coated in accordance with the present invention were tested for three different grades of High Efficiency Particulate Arresting (HEPA) filter elements (grades F7, F8 and F9). Grades F7, F8 and F9 are indications given to secondary filter elements depending on their efficiency they should reach according to the BS EN 779 test standard. The required efficiency in use (middle efficiency) depends on the particle size to be filtered.
For 0.4 μm particles, F7 grades should obtain a middle efficiency of 80-90%.
For 0.4 μm particles, F8 grades should obtain a middle efficiency of 90-95%.
For 0.4 μm particles, F9 grades should obtain a middle efficiency of more than 95%.
The filtration of this test media is charged, i.e. to form an electret, and may be used in heating, ventilation or air conditioning (HVAC) systems.
The initial and the middle filtration efficiency for 0.4 μm pores is measured according to standard European air filter test BS EN 779 for the standard filtration media and plasma coated filtration media in charged form and in discharged form. The filtration media is discharged by bringing into contact with isopropanol.
The initial filtration efficiency is the efficiency of a clean, brand new filter element. It is obvious that once the filter is in use, its pores become blocked by filtered particles, and by consequence its efficiency increases during lifetime. The initial efficiency is thus the minimal efficiency.
The results for the first fabric grade F7 are presented in Table 6. In order to pass the test the required average efficiency is 80 to 90% and the initial efficiency is 35% or more.
TABLE 6
Standard
Standard
Plasma
Plasma
Type of
F7—
F7—
treated F7—
treated F7—
filter
charged
discharged
charged
discharged
Initial
55%
39%
70%
64%
efficiency
0.4 μm
Average
85%
—
87%
87%
efficiency
0.4 μm
From Table 6 it is clear that the initial filtration efficiency for charged filter elements coated with an inventive coating is enhanced. Once the filters are discharged, the initial and average efficiency for standard filters drops highly, while the plasma treated filter elements do not show an efficiency drop for the average efficiency and a slight drop for the initial efficiency.
The results for the second fabric grade F8 are presented in Table 7. In order to pass the test the required average efficiency is 90 to 95% and the initial efficiency is 55%.
TABLE 7
Standard
Standard
Plasma
Plasma
Type of
F8—
F8—
treated F8—
treated F8—
filter
charged
discharged
charged
discharged
Initial
50%
33%
80%
87%
efficiency
0.4 μm
Average
83%
76%
92%
94%
efficiency
0.4 μm
From Table 7 it is clear that the initial and average filtration efficiency for charged filter elements coated with an inventive coating is enhanced. Once the filters are discharged, the initial and average efficiency for standard filters drops, while the plasma treated filter elements do show an efficiency increase for the average efficiency and for the initial efficiency.
The standard filter elements do not have the required average efficiency of 90-95%, while the plasma coated filters reach the spec for both charged and discharged.
The standard filter elements do not have the required initial efficiency of 55%, while the plasma coated filters reach the spec for both charged and discharged.
Filtration efficiency is enhanced for discharged filter elements coated with an inventive coating. After discharge with isopropanol, the coating is still on the filter element preventing the latter from showing a decrease in efficiency.
Penetration of Dispersed Oil Particles (DOP)
Respirator masks having five layers of nonwoven meltblown polypropylene (15-30 g/m 2 ) are electrostatically charged after coating with a coating according to Example 1. Evaluation of the penetration is done using a Certitest 8130 apparatus loading the textile with 200 mg of DOP-particles. The results are presented in Table 8.
TABLE 8
Initial
Penetration
penetration
after (x)
Filter medium
Conditioning
(%)
minutes (%)
Supplier I—28 g/m 2
Uncoated
1.20
6.40 (30)
Supplier I—28 g/m 2
Plasma coated
0.48
1.08 (30)
Supplier I—22 g/m 2
Uncoated
1.25
3.90 (10)
Supplier I—22 g/m 2
Plasma coated
0.40
0.75 (10)
Supplier II—25 g/m 2
Uncoated
N.A.
N.A.
Supplier II—25 g/m 2
Plasma coated
0.02
0.03 (10)
It is clear from Table 8 that the plasma coated materials perform much better than the uncoated reference materials. The initial penetration is about 3 times less; the penetration after 10 to 30 minutes is 5 to 6 times less. The filtration efficiency for oily particles is enhanced by using an inventive coating.
Filter Efficiency
Diesel filters made of approximately 1 to 2 mm thick nonwoven polyethylene terephthalate (PET) of 500 g/m 2 are coating with an inventive coating according to Example 2.
The efficiency is tested by soaking the filter elements in water for 22 hours, followed by a drip out of a certain time (minute range) in vertical position. The weight increase is calculated and compared to non-coated reference samples of the same material.
The results are presented in the following graph.
From the graph shown in FIG. 9 , it is clear that uncoated material absorbs a high volume of water, almost 1800% weight increase after 1 minute drip out.
Samples coated with an inventive coating show extremely low water absorption values, less than 10% weight increase after 1 minute drip out.
Washability
Three different polyester woven fabrics coated with a low power plasma coating according to Table 3 from Example 2 have been washed according to ISO 15797 (2002).
One complete washing cycle comprised the following steps:
1. Washing at 60° C. and using 20 g IPSO HF 234 without optical whitener per kilogram dry textile material; 2. Tumble drying; 3. Hot pressing at 180° C. (e.g. ironing).
Five washing cycles have been performed one after the other, then the oil repellency was measured according to ISO 14419 and a spray test was performed according to ISO 9073—part 17 and ISO 4920.
Next, five more washing cycles have been done and the oil repellency test and spray test have been repeated.
The oil repellency in function of the number of washing cycles is presented in FIG. 10 . FIG. 11 shows the spray test results in function of the number of washing cycles.
In a further example another polyester woven fabric has been coated with and without a pre-treatment prior to the coating step. The process without pre-treatment is carried out according to Example 1.
The process parameters for the process with pre-treatment are presented in Table 9.
TABLE 12
Parameter
Value
Pre-treatment
Gas
Argon
Flow
500-1000 sccm
Treatment speed
6 m/min
Power
500-750 W
Frequency
13.56 MHz
Frequency mode
cw
Liquid Monomer Supply
(LMS)
Temperature canister
130-150° C.
Temperature LMS
140-150° C.
Plasma Zone
Length of plasma zone
6 m
Coating step speed
2 m/min
Tension
1.5 kg (15N)
Temperature walls
40-50° C.
Electrodes & Generator
Electrode configuration
M/RF/M/RF/RF/M/RF/M
Plasma type
Primary
Power during coating
100-500 W
Frequency
13.56 MHz
Frequency mode
cw
Temperature RF electrode
30-35° C.
Monomer
1H,1H,2H,2H-Perfluorooctyl acrylate
Flow
40-100 sccm
Pressure
Base pressure
10-50 mTorr
Work pressure
20-80 mTorr
Residence time in plasma
3 minutes
zone during coating
Oleophobicity Level
5
(ISO 14419-2010)
The coated textiles have been washed according to ISO 15797 (2002).
One complete washing cycle comprised the following steps:
1. Washing at 75° C. and using 20 g IPSO HF 234 without optical whitener per kilogram dry textile material; 2. Drying in a drying cabinet;
After one washing cycle the oil repellency was measured according to ISO 14419 and a spray test was performed according to ISO 9073—part 17 and ISO 4920.
Next, four more washing cycles have been completed and the oil repellency test and spray test have been repeated (values measured after 5 washings).
Next, five more washing cycles have been done and the oil repellency test and spray test have been repeated (values measured after 10 washings).
The oil repellency as a function of the number of washing cycles is presented in FIG. 12 . FIG. 13 shows the spray test results in function of the number of washing cycles.
From tables 13 and 14 it is clear that the textile samples that were pre-treated prior to coating have a better performance in washing. The improvement is more pronounced in spray testing, where the water repellency is tested. The difference in the level of oil repellency becomes visible after 10 washing cycles, as can be seen in FIG. 12 . After 20 washing cycles the pre-treated fabric still has oil repellency level 3.
Abrasion Durability
Three different polyester woven fabrics coated with a low power plasma coating according to Example 2 have undergone an Martindale abrasion test. Because afterwards a spray test was performed, larger samples than normal were needed, and the set-up was slightly changed.
A standard wool fabric was pressed with a force of 9 kPa onto a larger coated PES woven fabric. 5000 abrasion cycles have been done and the oil repellency was measured according to ISO 14419 and a spray test was performed according to ISO 9073—part 17 and ISO 4920. Then 5000 more abrasion cycles have been done and the oil repellency test and spray test have been repeated.
FIG. 14 shows the oil repellency in function of the number of Martindale abrasion cycles and FIG. 15 shows the spray test results in function of the number of Martindale abrasion cycles. | The invention provides a method of coating a fabric, e.g. a textile material, with a polymer coating, which method comprises contacting a fabric with a monomer and subjecting the monomer to low power plasma polymerization, wherein the monomer comprises the general formula (I): C n F 2n+1 C m X 2m CR 1 Y—OCO—C(R 2 )═CH 2 , wherein n is 2 to 6, m is 0 to 9, X and Y are H, F, Cl, Br or I, R 1 is H or alkyl, e.g. —CH 3 , or a substituted alkyl, e.g. an at least partially halo-substituted alkyl, and R 2 is H or alkyl, e.g. —CH 3 or a substituted alkyl, e.g. an at least partially halo-substituted alkyl. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to an arrangement for reinforcing a door, particularly a multi-sectional garage door of the sliding, or up and over type.
Conventional doors of this type, particularly as used in double car garages are generally constructed of horizontal, elongated sections, hingedly attached one to the other. Rollers positioned on each side of each section cooperate with tracks in a conventional garage door frame such that the door can be moved between an open or closed position. To assist the user in raising and lowering the door, springs and cables are utilized to balance the weight of the door and reduce the load.
Such double-width doors tend to sag as time progresses, this problem is due mainly to the combination of the upward spring tension on the sides of the door, or the manner in which the cable assembly is attached to the lower side corners of the door, where the entire weight of the door is carried.
To provide reinforcement for doors is not new, as can be seen from Canadian Patents Nos. 186374 issued to J. Little in Sep. 1918; 517184 issued to J. F. McKee in Oct. of 1955; and U.S. Pat. No. 2804953 issued to A. M. Buehler in Dec. 1955. However, none of these prior art structures can be utilized in connection with folding, multi-sectional doors.
An attempt was made to solve this problem by Robert Wold who obtained Canadian Patent No. 1299493 on the 28th of Apr. 1992. This arrangement in structural terms is reverse to that of the subject application and substantially more complicated.
The object of the present invention is therefore to provide a simple and effective device for use in the reinforcement of multi-sectional doors.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a system for reinforcing multi-sectional doors of the type including multiple horizontal panels interconnected at each longitudinal side to adjacent panels, the system includes corner reinforcing plates adapted to be attached to opposite lower corners of a bottom panel structure of a door. The longitudinal struts are attached to each of the corner plates and extend upwardly and inwardly of the panel structure. The upper end of each strut being attached to an upper connector such that a combination of the corner plates, struts, and connector define a substantially rigid triangular frame within the confines of the lower panel section of the door structure. A load pin extends downwardly from the upper connector to a lower bracket, the latter being attached to the bottom of the door. An intermediate bracket located vertically above the lower bracket and also attached to the door is positioned to support and locate the pin which is positioned through apertures in both the lower bracket, intermediate bracket and upper connector. A locking nut arrangement maintains the pin in position on the lower bracket and provides means for adjusting the height of the pin. A nut is provided at the upper threaded end of the pin which when tightened, exerts an upward pull on the bottom of the door, while exerting a compressive force via the struts to the corner plates, hence substantially eliminating sagging.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only, reference being had to the accompanying drawings in which:
FIG. 1 is an elevational view of the inside of a multi-sectional door with a reinforcing device in accordance with prior art;
FIG. 2 is an elevational view of the inside of a multi-sectional door with a reinforcing device in accordance with the present invention;
FIG. 3 is a detailed elevational view of the upper portion of the device according to FIG. 2;
FIG. 4 is a perspective view of the load pin assembly of the device according to FIG. 2 showing a structural variation;
FIG. 5 is an elevational view of one strut of the reinforcing device according to FIG. 4; and
FIG. 6 is a perspective detailed view of a corner structure according to FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, the prior art structure shown in FIG. 1 is that disclosed in previously referenced Canadian Patent No. 1299493. The device shown comprises two composite struts each including three flat metal strips 10, 11 and 12, and an associated intermediate turnbuckle 14. The lower ends of strips 10 are connected pivotally to the bottom centre of the frame of a panel 2 of the door, and the upper ends of strip 12 ace connected to the side edge on the lower edge of the frame of the door frame 15.
Turnbuckle 14 is connected between strips 11 and 12. The principle behind this prior art structure is that by adjusting each turnbuckle separately, one can exert an upward and angularly outwardly outer force on the bottom of the door, ostensibly to offset sagging.
Since the two composite struts of the prior art are fixedly attached to the bottom centre of the door and to the edge of door frame 15, it is necessary to provide for adjustment in length of each strut to compensate for dimensional changes hence the requirement for two inter-connected members 11 and 12, with associated connectors. One major problem witch the prior art arrangement panel is that the door panel is caused to bow outwardly or inwardly upon turnbuckle adjustment.
The present invention, as can be seen from FIG. 2, comprises the following components: Two flat metal strips 17 and 18; bottom corner door plates 19 and 20; upper bracket 21; lower bracket 22; intermediate bracket 23; and load pin 24. The two struts or strips 17 and 18 are rigidly attached, for example, as by welding, at upper and lower ends to the upper bracket 21, and bottom corner plates 19 and 20, respectively, to provide for a rigid, substantially triangular framework.
Bottom corner plates 19 and 20 are attached by suitable means to the lower corners of the door and to a conventional spreader plate or bar 25, the latter being generally included as part of the door structure on installation. Bar 25 serves to maintain the constant width of the door, hold the bottom of the door rigid, and to prevent downward sag when the door is in the raised position.
Load in or shaft 24 (FIG. 4) is a rod of circular cross-section, the upper and lower ends 26 and 26A being threaded.
Load pin 24 is centrally and vertically located on a framing member of lower panel 2 of the door and is held vertically in respect of the inside of the door by brackets 22 and 23, both of which brackets are attached, by either bolts or rivets, as can be seen from FIG. 2 and 4, to the lower section or panel 2 of the door.
Intermediate bracket 23 has a centrally aligned hole through which shaft or pin 24 freely passes, this bracket simply acts as a stabilizer or guide for pin 24, and in effect supports the reinforcing device from movement when the garage doors are in the raised or upper overhead position.
Lower bracket 22 also has a central hole through which pin 24 passes, which serves to anchor the pin 24 but, by means of a lock nut system 27, permits vertical adjustment of the pin 24 to facilitate accurate component assembly.
Finally, as can be seen from FIGS. 2, 3 and 4, upper bracket 21 also has a hole to permit the upper end of the shaft to freely pass through, and a nut 27 is included to threadably engage with the upper end 26 of pin 24 to bear against the upper surface of bracket 21.
As will be appreciated, following component assembly, by tightening nut 27, an upward force is applied via the load pin or shaft 24 to the bottom center of the door. At the same time, a compression force is translated through struts 17 and 18 to respective bottom plates 19 and 20 and hence by their attachment, to the lower corners of the door.
Therefore, by installing a device of the present invention to either a new door, where all components will be welded rigidly one to the other as required, or to an existing door, in a retrofit, in kit form, where all components are individually attached such that a central system is provided whereby sagging is substantially controlled or eliminated.
As can be seen from the drawings provided herein, there are certain structural differences as between FIG. 2 and FIG. 4. Whereas in its simplest form, (FIG. 2), the struts 17 and 18 can be flat, metal strips or bars, in FIG. 4, 5 and 6 the arrangement utilizes a square-sectioned tube as the principle member of the struts 17 and 18. Upper bracket 21 could be positioned with the tube by either rivets, pinning, welding or indeed by force or friction fit. This configuration would also necessitate, as shown in FIG. 5, a variation in the configuration of the bottom plates 19 and 20, which can be formed as an extension of the material or as a separate bolted on plate. Both arrangements can be considered equivalent structures, however, the square tube construction may have advantages as to imparting more rigidity to the overall structure.
Since various modifications can be made to the structure as hereinabove described without departing from the spirit and scope of the claims. For example, to facilitate any required adjustment in length of struts 17 and 18 to accommodate slight variations in door width, each of struts 17 & 18 could be composed of two separate sections, one telescoping within the other. Further, additional brackets could be utilized to hold struts 17 and 18 against the door 2, these brackets being located to be attached to the door panel as frame, it is intended therefore, that all matter contained in the accompanying specification, shall be interpreted as illustrative only and not in a limiting sense. | A reinforcing arrangement or device which substantially prevents sagging of the lower section of a multi-sectional Up and over type door. The natural load on the lower center of the bottom panel of the door being upwardly and vertically controlled and translated laterally and downwardly to the bottom corners the door by the device, to maintain overall conformity. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a cutting apparatus and, more particularly, to a multi-height can body cutting apparatus that is practical to cut a can body into different heights.
A variety of can body cutting apparatus are commercially available. DE3619322 shows an example. However, conventional can body cutting apparatus are designed for cutting a can body into a particular height only.
SUMMARY OF THE INVENTION
The present invention has been accomplished to provide a multi-height can body cutting apparatus that is practical to cut a can body into different heights. According to one aspect of the present invention, the multi-height cutting apparatus comprises a fixed cutting tool means disposed around a central axis, the fixed cutting tool means having at least one cutting edge, and a plurality of rotary cutting tool means spaced between the column and the fixed cutting tool means and respectively rotated to cut can bodies being delivered one after another through a circular path between the at least one cutting edge of the fixed cutting tool means and the rotary cutting tool means, the at least one cutting edge of the fixed cutting tool means each having a stepped cutting structure, the rotary cutting tool means each having a cutting edge in a stepped structure thereof corresponding to the at least one cutting edge of the fixed cutting tool means for cutting each delivered can body at different heights. According to another aspect of the present invention, the multi-height cutting apparatus further comprises a shaft axially mounted in the column, and a rotary table mounted on the top side of the shaft and adapted for rotating can bodies on the rotary cutting tool means against the at least one cutting edge of the fixed cutting tool means. According to still another aspect of the present invention, one half of the outer diameter of said rotary table is greater than the shortest distance between the at least one cutting edge of the fixed cutting tool means and the longitudinal central axis minus the diameter of the can bodies. According to still another aspect of the present invention one half of the outer diameter of the rotary table is about equal to ½˜⅚ of the shortest distance between the at least one cutting edge of the fixed cutting tool means and the longitudinal central axis minus the diameter of the can bodies, or preferably equal to ⅔ of shortest distance between the at least one cutting edge of the fixed cutting tool means and the longitudinal central axis minus the diameter of the can bodies. According to still another aspect of the present invention, the rotary table has a grained peripheral face. According to still another aspect of the present invention, the fixed external cutting tool means comprises a top cutting segment, an intermediate cutting segment, and a bottom cutting segment; the rotary cutting tool means comprises a shank, a first end block and a second end block respectively provided at top and bottom ends of the shank, a barrel supported on spring means around the shank between the end blocks. According to still another aspect of the present invention, the rotary cutting tool means has barrel-like external flexible members disposed at top and bottom sides of the stepped cutting edge thereof. According to still another aspect of the present invention, the cutting edge the cutting blade of the fixed cutting tool means is corrugated and extended vertically along the length of the cutting blade. According to still another aspect of the present invention, the rotary table has a grained cylindrical peripheral face. According to still another aspect of the present invention, the rotary cutting tool means is matched with a pair of rolling barrels adapted for guiding each can body into position for cutting. According to still another aspect of the present invention, the rotary table is connected in parallel to the rotary carrier and turned about the longitudinal central axis, having a plurality of rollers arranged in pair in parallel to the longitudinal central axis at the periphery thereof and adapted for squeezing the can body on each of the rotary cutting tool means against the fixed cutting tool means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view taken along line I—I of the cutting apparatus constructed shown in FIG. 2 .
FIG. 2 is a top view of a cutting apparatus constructed according to the present invention.
FIG. 3 illustrates the position of the rotary cutting tool relative to the external cutting tool before the entry of the workpiece (position P 1 in FIG. 2 ).
FIG. 4 illustrates the position of the rotary cutting tool relative to the external cutting tool upon the entry of the workpiece (position P 2 in FIG. 2 ).
FIG. 5 illustrates the position of the rotary cutting tool relative to the external cutting tool during cutting (position P 3 in FIG. 2 ).
FIG. 6 is a sectional view of a part of the smoothly arched external cutting tool according to the present invention.
FIG. 7 is a sectional view of a part of a cutting apparatus according to a second embodiment of the present invention.
FIG. 8 is a top view of a part of the cutting apparatus according to the second embodiment of the present invention.
FIG. 9 is a sectional view taken along line IX—IX of FIG. 8 .
FIG. 10 is a top view showing a fixed cutting tool with a corrugated cutting edge according to the present invention.
FIG. 11 is a top plain view of a part of another alternate form of the present invention.
FIG. 12 is a sectional view showing rollers arranged at top and bottom sides of the rotary table and pressed on the periphery of the can body against the rotary cutting tool according to the present invention.
FIG. 13 is a sectional view showing the elastic rotary barrel of the rotary cutting tool pressed on the peripheral wall of the can body against the butting blade of the fixed cutting tool according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a cutting apparatus 1 is shown comprising a machine base 2 , a column 3 vertically disposed at the center inside the machine base 2 , a rotary carrier 4 mounted around the column 3 and turned about the longitudinal central axis 5 of the column 3 , an annular gear 6 fixedly fastened to the bottom sidewall of the rotary carrier 4 , a pinion 8 meshed with the annular gear 6 , and a driving unit 7 adapted to rotate the pinion 8 . The rotary carrier 4 comprises a plurality of vertical guide holes 9 equiangularly spaced from one another and disposed in parallel to the longitudinal central axis 5 of the column 3 . Axles 10 are respectively slidably mounted in the vertical guide holes 9 , each having a peripheral wedge block 13 inserted into a vertical guide groove 14 in the corresponding vertical guide hole 9 . Rollers 11 are respectively coupled to the axles 10 below the rotary carrier 4 and coupled to a peripheral groove 12 in the bottom flange of the column 3 . Four rotary cutting tools 15 are provided above the axles 10 . The rotary cutting tools 15 are shaped like a stepped cylinder, each comprising a thinner top tool body 16 , a thicker bottom tool body 17 , and a cutting edge 18 disposed between the thinner top tool body 16 and the thicker bottom tool body 17 . Cylindrical members 19 are respectively fixedly connected to the thicker bottom tool body 17 of each of the rotary cutting tools 15 . Transmission gears 20 are respectively fixedly mounted on the cylindrical members 19 . When the transmission gears 20 meshed with an internal gear 23 in the machine base 2 , the rotary cutting tools 15 are rotated on their own axis during rotary motion of the rotary carrier 4 , and at the same time the cylindrical members 19 are respectively engaged into respective holes 21 in to the flange 22 above the rotary carrier 4 . The rotary cutting tools 15 control the elevation of the axles 10 in the vertical guide holes 9 . The internal gear 23 has a height corresponding to the moving range of the axles 10 in the vertical guide holes 9 .
A smoothly arched external cutting tool 25 is fixedly mounted on the machine base 2 and extended through about 288° around the rotary cutting tools 15 . An input gear 26 and an output gear 27 are respectively disposed at two distal ends of the external cutting tool 25 . The external cutting tool 25 has an upper cutting segment 28 , a lower cutting segment 29 , and a cutting edge 30 in the bottom side of the upper cutting segment 28 . The cutting edge 30 is comprised of an inner face 31 and a bottom coating layer 32 . The lower cutting segment 29 has an inner face 33 .
A shaft 34 is axially mounted in the column 3 . A rotary table 35 is mounted on the top side of the shaft 34 , having a grained peripheral face 36 . A first bevel gear 37 is fixedly mounted on the bottom side of the shaft 34 . A second bevel gear 38 is meshed with the first bevel gear 37 and coupled to the driving unit 7 through a transmission mechanism 39 . The transmission mechanism 39 is an adjustable transmission gearbox.
There is a pitch in the entrance (the position P 1 shown in FIG. 2) between the inner faces 31 and 33 of the external cutting tool 25 and the path for the rotary cutting tools 15 around the longitudinal central axis 5 of the column 3 for receiving cylindrical can body C.
During rotary motion of the rotary carrier 4 relative to the peripheral groove 12 in the bottom flange of the column 3 , the rotary cutting tool 15 between the input gear 26 and the output gear 27 is pulled to the area below the external cutting tool 25 (see FIG. 3 ). When moved over the input gear 26 , the rotary cutting tool 15 is guided upwards into the inside of the corresponding can body C. The pitch between the inner face 31 of the external cutting tool 25 and the grained peripheral face 36 of the rotary table 35 is sufficient for the passing of the can body C. During rotary motion of the rotary carrier 4 , the can body C is received in the cutting apparatus 1 . The revolving speed of the rotary table 35 is about twice the speed of the rotary cutting tools 15 , so that the can body C at each rotary cutting tool 15 is respectively turned from the rotary table 35 to the external cutting tool 25 .
During the operation of the cutting apparatus 1 , the can body C is squeezed against the inner face 31 of the cutting edge 30 . The pitch between the cutting edge 18 of each rotary cutting tool 15 and the cutting edge of the external cutting tool 25 is gradually reduced in direction from the input end (the side of the input gear 26 toward the output end (the side of the output gear 27 ), so that can bodies C of different heights are cut off at a predetermined cutting line L into equal height.
FIG. 7 shows a cutting apparatus 41 suitable for cutting the workpiece into three different heights. According to this alternate form, the fixed external cutting tool 42 of the cutting apparatus 41 comprises three segments, namely, the top cutting segment 43 , the intermediate cutting segment 44 , and the bottom cutting segment 45 disposed at different elevations. The intermediate cutting segment 44 has an inner face 46 and two cutting edges 47 and 48 respectively disposed at the top and bottom sides of the inner face 46 . The rotary cutting tool, referenced by 50 , comprises a shank 51 , a first end block 53 and a second end block 55 respectively provided at the top and bottom ends of the shank 51 , a barrel 54 supported on spring means 52 around the shank 51 between the end blocks 53 and 55 . When standing still, the barrel 54 and the end blocks 53 and 55 are coaxially aligned. Same as the embodiment shown in FIGS. from 1 through 6 , the rotary cutting tools 50 of the cutting apparatus 41 are rotated and moved up and down during the operation of the cutting apparatus 41 .
The distance between the inner face 46 of the intermediate cutting segment 44 of the fixed external cutting tool 42 and the longitudinal central axis 5 is gradually reduced in the path. Therefore, the rotary cutting tool 50 gives a pressure to the can body C against the inner face 46 of the intermediate cutting segment 44 of the fixed external cutting tool 42 . Following the reducing of the radius of the inner face 46 , the cutting edges 47 and 48 of the fixed external cutting tool 42 work with the cutting edges 57 and 58 of the rotary cutting tool 50 to cut the workpiece into three heights. During cutting, the barrel 54 is forced to roll off the workpiece.
FIGS. 8 and 9 show a cutting apparatus 61 practical for cutting the workpiece into two heights. According to this alternate form, the fixed external cutting tool 62 comprises an upper tool body 65 , a lower tool body 66 , and a cutting blade 63 sandwiched in between the upper tool body 65 and the lower tool body 66 . The cutting blade 63 has a cutting edge 64 perpendicularly aimed at the longitudinal central axis 5 . The upper tool body 65 and the lower tool body 66 have a vertical inner sidewall 67 (see FIG. 9 ). Similar to the embodiment shown in FIGS. 1 and 2, the cutting apparatus 61 comprises a rotary table 35 adapted to be turned about the longitudinal central axis 5 and having a grained peripheral face 36 , a rotary carrier 4 adapted to be turned about the longitudinal central axis 5 , and a plurality of rotary cutting tools 70 respectively mounted in respective guide holes (not shown) in the rotary carrier 4 . The rotary cutting tools 70 function in the same way as that of the embodiment shown in FIGS. 1 and 2.
Each rotary cutting tool 70 comprises two cylindrical end blocks 71 and 72 , and a peripheral groove 73 between the end blocks 71 and 72 . The vertical height h 73 of the peripheral groove 73 is about {fraction (10/7)} or 1.43 of the height h 0 of a well-cut can body.
In order to guide the can bodies C into the path for cutting, each rotary cutting tool 70 is equipped with two rolling barrels 75 mounted on the rotary carrier 4 .
Referring to FIG. 10, the fixed cutting tool 62 ′ comprises a cutting blade 63 ′ having a corrugated cutting edge 64 ′ extended vertically along the length. The rotary cutting tool 70 rolls off the can body C carried thereon, producing a buffering effect when cutting the can body C into two heights.
Referring to FIG. 11, a rotary table 80 is turned about the longitudinal central axis. The revolving speed of the rotary table 80 is equal to the rotary carrier 4 . Rollers 81 , 82 , and 83 are provided at the rotary table 80 and arranged in sets corresponding to the rotary cutting tools 70 . Rollers 81 , 82 , and 83 are moved with the rotary table 80 relative to the rotary cutting tools 70 to squeeze the can body C on each rotary cutting tool 70 . Each set of rollers include a first roller 81 and a second roller 82 equally spaced from the longitudinal central axis 5 , and a third roller 83 defining with the first roller 81 and the second roller 82 a can body C receiving mouth 84 .
Referring to FIG. 12, rollers 88 a ˜ 83 a and rollers 81 b ˜ 83 b are symmetrically arranged at top and bottom sidewalls of the rotary table 80 .
Referring to FIG. 13, the rotary cutting tool 90 is comprised of a cylindrical shaft 92 and an elastic barrel 91 sleeved onto the. shaft 92 . The elastic barrel 91 is made of elastic material, for example, polyurethane. The peripheral wall of the can body C is supported on the periphery of the elastic barrel 91 and pressed against the cutting blade 63 , and therefore the can body C is cut smoothly without producing a curved edge.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A multi-height cutting apparatus includes a fixed cutting tool means disposed around a central axis, the fixed cutting tool means having at least one cutting edge, and a plurality of rotary cutting tool means spaced between the column and the fixed cutting tool means and respectively rotated to cut can bodies being delivered one after another through a circular path between the at least one cutting edge of the fixed cutting tool means and the rotary cutting tool means, the at least one cutting edge of the fixed cutting tool means each having a stepped cutting structure, the rotary cutting tool means each having a cutting edge in a stepped structure thereof corresponding to the at least one cutting edge of the fixed cutting tool means for cutting each delivered can body at different heights. | 8 |
This application claims the benefit of U. S. Provisional Application, Ser. No. 60/118,948, filed Feb. 5, 1999 entitled SOLAR CELL COVER GLASS, by Paul S. Danielson and Ronald L. Stewart.
FIELD OF THE INVENTION
Glasses adapted to produce microsheet cover glass for use in solar cells.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,746,634 (Danielson) discloses glasses having borosilicate compositions developed for production of microsheet to be used in cover glasses on solar cells. The cover glasses are strongly resistant to solarization, exhibit a cutoff value of 50% at 370 nm. for ultraviolet (UV) radiation, and have properties adapted to forming microsheets.
The glass compositions disclosed in the Danielson patent consist essentially of, expressed in terms of weight percent on an oxide basis:
SiO 2
59-63
ZnO
6.5-7.5
B 2 O 3
8.75-10
CeO 2
4-6
Al 2 O 3
2-2.5
TiO 2
1-3
Na 2 O
6.75-7.75
CeO 2 + TiO 2
6-8
K 2 O
6.25-7.0
Sb 2 O 3
0-0.5
A commercial glass, based on these composition ranges, was developed that has proven eminently satisfactory for use in producing microsheet cover glass for solar cells. Recent developments in solar cell use, particularly for space vehicles or a station, have imposed severe limitations on cover glasses for such cells.
One such requirement is to provide as great a solar spectral transmission as possible. This is necessary to provide maximum efficiency in solar cells used to provide power to space vehicles. It is a purpose of the present invention to provide a cover glass improved in these respects, and a solar cell embodying such cover glass.
In this regard, another purpose is to provide a glass having a sharp cutoff in the UV portion of the spectrum. This maximizes solar intensity while still protecting an organic adhesive against deterioration by shorter wavelength, UV radiation.
Finally, the possible danger of a static electrical discharge in a space vehicle imposes a requirement of a lower bulk electrical resistivity in the glass. This is necessary to aid in reducing buildup of static charge on the space vehicle. It is, then, another purpose to provide a cover glass having a low bulk resistivity.
Over and above providing these several improvements, it has also been required that the properties described in the Danielson patent for forming microsheet glass be at least retained, and preferably improved. A final purpose, then, is to reach this desired end.
SUMMARY OF THE INVENTION
The invention resides, in part, in a glass that has properties that permit the glass to be drawn as microsheet, that has a transmission greater than about 90% at wavelengths greater than 370 nm., that has a sharp cutoff between 310-370 nm., that has a transmission no greater than about 50% at about 330 nm., and that has a composition consisting essentially of, expressed in terms of weight percent on an oxide basis:
SiO 2
59-69
ZnO
6.5-8.5
B 2 O 3
8.5-14
CeO 2
0.25-3
Al 2 O 3
2-2.5
TiO 2
0-1
Na 2 O
5.5-12.5
CeO 2 + TiO 2
0-0.5
K 2 O
0-8
Sb 2 O 3
0-0.5
The invention further resides in a solar cell having, as a component, a cover glass as defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawing,
FIG. 1 is a schematic side view of a solar cell constructed with a cover glass in accordance with the present invention.
FIG. 2 is a graphical representation illustrating the transmission characteristics of glasses in accordance with the present invention.
DESCRIPTION OF THE INVENTION
The present invention arose from efforts to provide improved properties in a glass commercially available in microsheet form. While not so limited, the glass, drawn as microsheet, finds specific application as a cover glass for solar cells, and is so described here.
Microsheet may be drawn in a range of thicknesses, e.g., 50-500 microns. However, the conventional thickness for a microsheet cover glass used in solar cells is 150 microns (0.006 inches). Hereafter, all references will be to microsheet of that thickness, unless otherwise indicated.
Solar cells were devised as a means of converting solar radiation into a source of electricity, primarily for residential use. More recently, attention has turned to use of such solar cells as a source of power for spacecraft. This utility has imposed new requirements, as well as enhancing the original requirements.
FIG. 1 is a schematic side view of a simple solar cell generally designated 10 . Solar cell 10 is basically composed of a cover glass 12 sealed to the main body of the cell 14 by a seal 16 . The present invention is not concerned with the construction, or functioning, of main body 14 . Therefore, that component is shown only as a shell in the interest of simplicity.
Cover glass 12 is commonly a layer of glass microsheet sealed to the main body 14 . It acts as a shield to prevent dust, or other debris, from entering the cell. Seal 16 may be a fusion seal if care is taken to closely match the coefficient of thermal expansion (CTE) of the material in body 14 with that of the glass 12 . However, it is frequently desirable to avoid this limiting effect on the materials of body 14 and glass 12 . Seal 16 may, therefore, be an organic plastic material.
However, short wavelength UV radiation may deteriorate this plastic material. Therfore, it becomes necessary to essentially eliminate much of the UV portion of the radiation impinging on cover glass 12 , preferably by absorption in the glass. At the same time, it is desirable to secure as high a transmission of the useful portion of the solar radiation as possible. This combination of requirements has made it critical to obtain a very sharp, transmission cutoff in the long wavelength portion of the UV spectrum in cover glass 12 .
Cover glass 12 should provide maximum transmission of solar radiation at wavelengths in the visible portion of the spectrum, that is, wavelengths greater than 400 nm. Concomitant therewith, the glass should transmit minimal radiation in the UV portion of the spectrum below 310 nm. In other words, the transmission curve in the vicinity of 340 to 350 nm. in the UV portion of the spectrum should be as sharp, or steep, as possible.
This boundary portion of the curve is commonly referred to as the edge, or cut-on. A customary measure is the transmission in percent of a 150 micron thick glass at a wavelength of 370 nm. However, the present glasses provide a sharp edge positioned at shorter UV wavelengths. This edge is better characterized by transmission values at 330, 350 and 370 nm.
The invention is further described with reference to specific embodiments, and to relevant properties of those embodiments.
TABLE I shows, in weight percent on an oxide basis, the compositions for several glasses in accordance with the present invention. For comparison, the composition of example 5 in TABLE I of the Danielson patent is included as example 20 in present TABLE I.
TABLE I
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
SiO 2
63.9
63.4
64.15
63.65
64.4
65.15
64.35
63.9
65.4
66.4
66.4
66.5
66.5
65.9
66.0
Al 2 O 3
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
B 2 O 3
9.3
9.3
9.3
9.3
9.3
9.3
9.3
9.3
9.3
9.3
9.29
9.29
9.29
9.30
9.30
Na 2 O
7.15
7.15
10.1
10.1
7.15
7.15
10.1
10.1
7.15
7.15
10.1
10.1
11.8
7.15
7.15
K 2 O
6.65
6.65
3.7
3.7
6.65
6.65
3.7
3.7
6.65
6.65
3.7
3.7
2.0
6.65
6.65
ZnO
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
CeO 2
2.5
3.0
2.5
2.0
2.5
2.0
2.5
3.0
2.0
0.75
0.75
0.75
0.75
1.25
1.25
TiO 2
1.0
1.0
0.75
0.75
0.5
0.25
0.25
0.5
0
0.25
0.25
0.15
0.15
0.25
0.10
Sb 2 O 3
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
SiO 2
66.6
66.0
66.1
66.2
61.4
66.1
65.9
66.1
66.3
67.3
67.3
65.6
65.4
65.7
64.45
Al 2 O 3
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
2.25
B 2 O 3
9.30
9.30
9.30
9.30
9.30
9.30
9.30
13
13
14
14
9.30
9.30
9.30
11.10
Na 2 O
7.15
7.15
7.15
7.15
7.15
7.15
10.1
10.1
6.9
5.9
6.9
7.15
7.15
7.15
7.15
K 2 O
6.65
6.65
6.65
6.65
6.65
6.65
3.7
—
3.0
1.0
—
6.65
6.65
6.65
6.65
ZnO
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
8.0
8.0
7.0
7.0
7.0
7.0
CeO 2
0.5
0.4
0.5
0.4
5.0
1.0
1.0
1.0
1.0
1.0
1.0
0.75
1.0
1.25
0.50
TiO 2
0.25
1.0
0.75
0.75
1.0
0.25
0.5
0.25
0.25
0.25
0.25
1.0
1.0
0.75
0.75
Sb 2 O 3
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
FIG. 2 is a graphical representation illustrating the transmission characteristics of glasses in accordance with the present invention. Transmittance values, in percent, are plotted on the vertical axis; wavelengths in nm. are plotted on the horizontal axis.
In FIG. 2, curve A is the transmission curve for a glass having the composition shown as example 5 in TABLE I of the Danielson patent (example 20 in present TABLE I). Curves B and C are transmission curves for glasses having, respectively, compositions 8 and 10 in TABLE I of this application.
It will be noted that curves B and C for the present glasses are positioned to the left of Curve A and are significantly steeper than curve A. This provides the desired sharp transmission edge in the UV portion of the spectrum while positioning the edge at somewhat shorter wavelengths. Thus, the total solar radiation transmitted by the present glasses is enhanced.
This result was achieved by decreasing the contents of both CeO 2 and TiO 2 in the present commercial glass. The result was particularly surprising since it was believed that the larger contents were necessary to impart adequate resistance to discoloration, and consequent loss of transmission. This was particularly true with respect to use in space where the problem is much more severe than on earth. On earth, the atmosphere functions as a solarization shield. It was, then, quite unexpected to find that less than 2% CeO 2 , and as little as 0.25%, both by weight, could provide adequate resistance to solarization in space.
Accordingly, CeO 2 contents are preferably at least 0.25% by weight, but less than 2.0%. The TiO 2 content is at least 0.25% by weight, and may range up to about 1.0%.
As explained earlier, solar cells are used on spacecraft as a source of power. However, such spacecraft power components must not contribute to a buildup of static electrical charge on or in the spacecraft. This has led to a desire for a cover glass having a low bulk resistivity. It has been found that this desired end can be achieved in the present glasses by adjusting the ratio of Na 2 O/K 2 O. The ratio will be greater than 1:1, preferably greater than 2:1, and maybe up to 6:1.
TABLE II, below, demonstrates the reduction in resistivity that can be achieved in the present glasses without losing other properties. The TABLE shows log DC resistivity values at three different temperatures for four different glasses. The glasses are examples 20, 10, 4 and 13 in TABLE I. It will be seen that the resistivity of glasses 4 and 13 are substantially lower than the other two glasses.
TABLE II
Log (rho)
20
10
4
13
25° C.
15.26
15.33
13.88
12.79
250° C.
8.17
8.08
7.28
6.71
350° C.
6.66
6.55
5.87
5.43
A further, unforeseen advantage, accruing from the present glasses, is their relatively low liquidus temperatures, and their high viscosity values at the liquidus temperature. This combination of properties; tends to reduce the tendency for crystallization to occur during drawing of the microsheet. It also tends to avoid the formation of defect stones that grow in stagnant pockets of glass that occur in the microsheet drawing equipment. The tendency for these problems to occur has seriously limited the time between shutdowns required to clean the drawing equipment. This, of course, drives up the cost of production.
TABLE III, below, sets forth liquidus temperatures and viscosity values in kilopoises (kP) for six (6) of the glasses shown in TABLE I. As before, example 20 is the glass of example 5 in TABLE I of the Danielson patent. The liquidus values are internal liquidus values determined from a 24 hour, gradient test.
TABLE III
20
10
4
7
8
9
Comp'n/
942
810
865
865
835
840
Liq. T Int. (C)
HT visc. @ Liq. (kP)
50
2500
170
170
440
750
Broadly, the glasses of the present invention consist essentially of, in weight percent as calculated on an oxide basis:
SiO 2
59-69
ZnO
6.5-8.5
B 2 O 3
8.5-14
CeO 2
0.25-3.0
Al 2 O 3
2-2.5
TiO 2
0-1
Na 2 O
5.5-12.5
CeO 2 + TiO 2
0.5-4
K 2 O
0-8
Sb 2 O 3
0-0.5
Optimum properties, particularly a combination of maximum solar transmission with a sharp cutoff in the UV, are achieved with glasses having compositions consisting essentially of, in weight percent as calculated on an oxide basis:
SiO 2
59-69
ZnO
6.5-7.5
B 2 O 3
8.5-12
CeO 2
0.25-<2
Al 2 O 3
2-2.5
TiO 2
0.25-1
Na 2 O
6.5-12
Sb 2 O 3
0-0.5
K 2 O
2-8
A preferred glass composition is that shown as Example 30 in TABLE I. A glass having this composition has physical properties closely matching those of the present commercial glass corresponding to example 20 in TABLE I. This not only facilitates the transition to the new glass in the previously used melting unit, but also fabrication of the solar cell. In particular, the glass has a CTE of 74.3×10 −7 /° C. between 25° and 300° C., a softening point of 725° C. and a strain point of 5180° C. | A borosilicate glass having properties that enable it to be drawn as microsheets for use as a solar cell cover glass, and a solar cell having such microsheet as a cover glass, the glass having a composition consisting essentially of, expressed in terms of weight percent on an oxide basis:
SiO 2
59-69
ZnO
6.5-8.5
B 2 O 3
8.5-14
CeO 2
0.25-3
Al 2 O 3
2-2.5
TiO 2
0-1
Na 2 O
5.5-12.5
CeO 2 + TiO 2
0.5-4
K 2 O
0-8
Sb 2 O 3
0-0.5. | 2 |
FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a thin-film magnetic head and a manufacturing system of the thin-film magnetic head.
DESCRIPTION OF THE RELATED ART
In fabricating a thin-film magnetic head, a wafer with a large number of thin-film magnetic head elements is cut into rows so that a plurality of magnetic head sliders are sequentially coupled or aligned therein, and then each bar is processed for various works. In such working processes of each bar, it may be necessary to refer data inherent to the bar.
For example, control of a properties-determining height of a magnetoresistive effect (MR) head element (hereinafter referred to as MR height), which control is necessary for fabricating a thin-film magnetic head with the MR head element, is carried out by lapping an air bearing surface (ABS) of each bar. During the lapping of the ABS, the MR height is monitored by an electrical signal from a lapping control sensor called a RLG (Resistance lapping Guide) or EIG (Electric Tapping Guide) sensor to correct the bending of the bar and to control the stop position of lapping, so as to obtain optimum properties of the MR head element. In order to execute such a process using the RLG (or ELG) sensors, data inherent to the respective bars such as RLG center data which are different for the respective bars are required.
However, according to the conventional bar working process, data inherent to bars of each wafer are described on an independent recording paper, and this paper is transferred to the next process together with the wafer (workpiece), as described in, for example, Japanese unexamined patent publication No. 9(1997)-73615.
Thus, the workpieces have to be transferred from one working process to the next working process in a unit of wafer causing dwell time between the processes to increase. Furthermore, since each bar is visually identified and also identification signals or identifiers are manually input into a working machine, identification of the bar may take much time and incorrect bar working processes may be executed due to using of another bar data.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for manufacturing a thin-film magnetic head and a manufacturing system of the thin-film magnetic head, whereby dwell time between working processes can be reduced.
It is another object of the present invention to provide a method for manufacturing a thin-film magnetic head and a manufacturing system of the thin-film magnetic head, whereby the bar identification is accurately and easily carried out to improve the yield ratio.
According to the present invention, a method for manufacturing a thin-film magnetic head includes a step of cutting a wafer into bars, each bar having a plurality of thinfilm magnetic head sliders which are sequentially coupled with each other, a step of identifying the bar to be worked to generate an identification signal which indicates identity of the bar, a step of obtaining data of the bar individually on a per bar basis depending upon the identification signal, and a step of working the bar on the basis of the obtained data of the bar.
Since the data of bars are extracted individually on a per bar basis, movement of bars from one process to another process can be performed for the bars individually. As a result, each process can be smoothly carried out causing dwell time between the processes to reduce. Furthermore, workings of the bars obtained from one wafer can be simultaneously performed in parallel.
It is preferred that the data obtaining step includes a step of extracting the data from a table which stores retrievable relationships of identification signals and data of bars on a per bar basis.
It is also preferred that the bar identifying step includes a step of identifying a jig or a transfer tool to which the bar is attached. Although it is considerably difficult to identify a bar from bars themselves because of its small identification sign, it is comparatively easy to identify the jig itself to which the bar is attached. Thus, identification of bars to be worked will be accurate and easy, whereby the problem according to the conventional art that incorrect bar working processes are executed due to using of another bar data can be solved.
The bar identifying step may include a step of identifying the bar by using a table which stores relationships of identifiers of bars and identifiers of jigs to which the respective bars are attached. By using such a reference table, identification of bars in each working process can be certainly and rapidly performed.
The jig identifying step may include a step of identifying the jig by using a bar code provided on the jig. If the bar code is used as the identification sign, reading of the sign can be more accurately performed than in a case where other identification sign is used.
It is preferred that the processing step includes a height, control step of controlling properties of the thin-film magnetic head by lapping an ABS of a slider of the thin-film magnetic head, and that the obtained data include data used in the height control step.
In this case, the height control step includes a step of measuring resistance values which vary by the lapping, a step of calculating a properties-determining height of the magnetic head from the ABS, for example MR height or throat height etc., on the basis of the measured resistance values, and a step of comparing the calculated height with a target height. The obtained data include data used in the calculating step.
It is also preferred that the thin-film magnetic head has a taper portion, that the processing step includes a taper working step of lapping the taper portion, and that the obtained data include data of a chamfer length used in the taper working step.
According to the present invention, a system for manufacturing a thin-film magnetic head includes a unit for cutting a wafer into bars, each bar having a plurality of thin-film magnetic head sliders which are sequentially coupled with each other, a unit for identifying the bar to be worked to generate an identification signal which indicates identity of the bar, a unit for obtaining data of the bar individually on a per bar basis depending upon the identification signal, and a unit for processing at least one working of the bar on the basis of the obtained data of the bar.
Since the data of bars are extracted individually on a per bar basis, movement of bars from one process to another process can be performed by the unit of bar. As a result, each process can be smoothly carried out causing dwell time between the processes to reduce. Furthermore, workings of the bars obtained from one wafer can be simultaneously performed in parallel.
It is preferred that the data obtaining unit includes a unit for extracting the data from a table which stores retrievable relationships of identification signals and data of bars individually on a per bar basis.
It is also preferred that the bar identifying unit includes a unit for identifying a jig to which the bar is attached. Although it is considerably difficult to identify a bar from bars themselves because of its small identification sign, it is comparatively easy to identify the jig itself to which the bar is attached. Thus, identification of bars to be worked will be accurate and easy, whereby the problem according to the conventional art that incorrect bar working processes are executed due to using of another bar data can be solved.
The bar identifying unit may include a unit for identifying the bar by using a table which stores relationships of identifiers of bars and identifiers of jigs to which the respective bars are attached. By using such a reference table, identification of bars in each working process can be certainly and rapidly performed.
The jig identifying unit may include a unit for identifying the jig by using a bar code provided on the jig. If the bar code is used as the identification sign, reading of the sign can be further surely performed than in a case where other identification sign is used.
It is preferred that the processing unit includes a height control unit for controlling properties of the thin-film magnetic head by lapping an ABS of a slider of the thin-film magnetic head, and that the obtained data include data used by the height control unit.
In this case, the height control unit includes a unit for measuring resistance values which vary by the lapping, a unit for calculating a properties-determining height of the magnetic head from the ABS on the basis of the measured resistance values, and a unit for comparing the calculated height with a target height. The obtained data include data used by the calculating unit.
It is preferred that the thin-film magnetic head has a taper portion, that the processing unit includes a taper working unit for lapping the taper portion, and that the obtained data include data of a chamfer length used by the taper working unit.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view schematically illustrating a part of constitution of a RLG working system used in manufacturing of a thin-film magnetic head slider with a MR head element according to a preferred embodiment of the present invention;
FIG. 2 is a block diagram illustrating electrical constitution of the embodiment shown in FIG. 1;
FIG. 3 is a view schematically illustrating a planar structure of one of RLG sensors;
FIG. 4 is a flow chart schematically illustrating a flow of a RLG working process;
FIG. 5 is a view illustrating arrangement and pattern of MR head elements and RLG sensors on a bar; and
FIG. 6, which is constituted by combining FIGS. 6A and 6B, is a flow chart schematically illustrating a flow of a taper working process.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically illustrates a part of constitution of a RLG working system for carrying out a MR height working process and a taper working process according to a preferred embodiment of the present invention, and FIG. 2 illustrates electrical constitution of the embodiment in FIG. 1 .
In FIGS. 1 and 2, reference numeral 10 denotes a bar in which a plurality of thin-film magnetic head sliders formed by cutting a wafer (not shown) are aligned, 11 denotes a jig or a transfer tool for the RLG working to which the bar 10 is attached, 12 denotes a bar code reader for reading a bar code 13 provided on the jig 11 , 14 denotes a RLG working machine for carrying out the MR height working process and taper working process, 15 denotes a personal computer electrically connected to this RLG working machine 14 and the bar code reader 12 , 16 denotes a plurality of RLG sensors (lapping control sensors) provided on the bar 10 and connected to the computer 15 , 17 denotes a RLG database having a jig number database (JIGNODB) table 18 and a wafer database (WAFERDB) table 19 , 20 denotes an optical measuring device of RLG sensor height, and 21 denotes a chamfer length measuring device. The computer 15 , the RLG database 17 , the sensor height optical measuring device 20 and the chamfer length measuring device 21 can transmit and receive data through a network such as LAN 22 . Although not shown in FIG. 2, a plurality of sets each composed of the computer 15 and the RLG working machine 14 can be connected to the LAN 22 .
In this embodiment, the jig 11 is formed by a white ceramic material, and a black colored bar code which represents a jig number for identifying this jig itself (identification sign) is formed on a side surface of the jig 11 by laser processing.
The RLG working machine 14 conducts control of stopping position for MR height (or throat height) working of bar 10 , correction of bending of a bar, and working of a slider taper portion in control of the computer 15 . The structure of this type of working machine is well known from, for example, U.S. Pat. No. 5,620,356.
The RLG sensors 16 are simultaneously formed together with MR head elements in the wafer processing stage. The planar structure of one or the RLG sensors is shown in FIG. 3 which illustrates a plan view of MR head element portions and a RLG sensor port ion of the bar 10 . In this figure, although all the MR head element portions and the RLG sensor portion cannot be seen from outside due to an inductive head element multi-layered on this structure, a part of these layers on the bar 10 is transparently viewed.
In FIG. 3, reference numeral 10 denotes the bar, 10 a denotes an ABS of the bar 10 , which is to be lapped, 30 and 31 denote two of a plurality of MR head elements formed in one row along this bar 10 , 32 denotes one of the RLG sensors formed in a space area between the MR head elements 30 and 31 in parallel with these MR head elements, 30 a and 31 a denote MR layers of the respective MR head elements 30 and 31 , 30 b and 31 b, and 30 c and 31 c denote lead conductors connected to both ends of the MR layers 30 a and 31 a, 32 a denotes a resistor layer of the RLG sensor 32 , and 32 b and 32 c denote lead conductors connected to both ends of the resistor layer 32 a. The MR layers 30 a and 31 a and the resistor layer 32 a run in parallel with the ABS 10 a.
The JIGNODB table 18 is a reference table in which relationships of a wafer number for identifying the wafer, a bar number for identifying the bar 10 and a jig number of the jig 11 to which the bar 11 is attached are stored. The WAFERDB table 19 is a database in which a wafer number is used as a first retrieval key and a bar number is used as a second retrieval key. In the table 19 , various working data inherent to each bar are stored so that the data corresponding to different bars can be retrieved individually on a per bar basis.
The RLG sensor height optical measuring device 20 optically measures non-lapped RLG sensor height in the wafer processing stage. The optically measured data with respect to RLG sensor height hereinafter referred to as MSI data is transferred to the WAFERDB table 19 through the LAN 22 during the wafer processing stage. The chamfer length measuring device 21 measures a chamfer length, namely length of the taper portion of bar 10 . The measured data of the chamfer length is transferred to the computer 15 through the LAN 22 .
FIG. 4 schematically illustrates a flow of the RLG working process in this embodiment.
Before starting the RLG working process, data are prepared in the RLG database 17 (step S 0 ). That is, during the wafer processing stage, parameters inherent to each bar, which are necessary for calculation of MR height and calculated from measured resistance data from the RLG sensor 16 and MSI data from the optical measuring device 20 , working target values of the MR height and working standards (errors) arc stored in the WAFERDB table 19 for each bar in a unit of wafer. Furthermore, each bar 10 separated from the wafer by cutting is adhered to the working jig 11 , and relationships of the wafer number for identifying the wafer, the bar number for identifying the bar 10 and the jig number of the jig 11 to which the bar 10 is adhered are stored in the JICNODB table 18 .
The parameters inherent to each bar which are necessary for calculation of the MR height and stored in the WAFERDB table 19 are calculated as follows.
As shown in FIG. 5, a marker 50 , a plurality of MR head elements 51 , 52 , 53 , . . . , and RLG sensors 54 , 55 , 56 , . . . are formed on the single bar 10 in rows. The MR head elements 51 , 52 and 53 and the first, second and third RLG sensors 54 , 55 and 56 are alternately aligned. These RLG sensors 54 , 55 and 56 have patterns different from each other. A plurality of sets, for example, 12 sets of the first, second and third RLG sensors 54 , 55 and 56 are formed on the single bar 10 . This 12 sets case corresponds to a case of 30% shrink magnetic head. Edges 57 opposite to the ABSs 10 a of the MR head elements and the RLC sensors are aligned on the same line which is parallel to the ABS 10 a. Although omitted in FIG. 5, to these MR head elements and RLG sensors are connected lead conductors as shown in FIG. 3 .
Width and height of the first RLG sensor 54 are defined as W 1 and H 1 (μm), width and height of the second RLG sensor 55 are defined as W 1 and H 1 −10, width and height of the third RLG sensor 56 are defined as W 1 +10 and H 1 −10.
In order to correct a difference between a designed pattern size on a mask used for making these pattern and an actual pattern size of the bar, distance (MSI) between the edge 58 positioned on the ABS side of the marker 50 and the edges 57 opposite to the ABS side of the MR head elements and RLG sensors is measured by the optical measuring device 20 . Then, the difference between the measured MSI data and the designed value of 13 μm for example is added to or subtracted from H 1 . The designed value of H 1 is 20 μm, and the designed value of W 1 is also 20 μm.
A resistance value R 1 of the first RLG sensor 54 , a resistance value R 2 of the second RLG sensor 55 , and a resistance value R 3 of the third RLG sensor 56 are given by the following expressions;
R 1 =R L +( C+S×W 1 )/ H 1
R 2 =R L +( C+S×W 1 )/( H 1 −10)
R 3 =R L +{C+S× ( W 1 +10)}/( H 1 −10)
where RL represents a resistance value of lead conductors, S represents a sheet resistance value defined by the material and thickness of a resistor layer, and C represents other resistance (resistance value per a unit of height) such as crowding resistance.
(C+S×W 1 ) and R L can be calculated using R 1 and R 2 in these expressions as follows.
C+S×W 1 =−H 1 ×(H 1 −10)×( R 1 −R 2 )/10
R L =R 1 +( H 1 −10)×( R 1 −R 2 )/10
Thus, (C+S×W 1 ) and R L are calculated with H 1 corrected by MSI data and resistance data R 1 and R 2 actually measured by the first and second RLG sensors 54 and 55 , using the above-described expressions. Then, the obtained values are stored in WAFERDB table 19 .
RLG working process is actually started from stop S 1 in FIG. 4 . First, the jig 11 to which the bar 10 to be lapped is adhered is placed on the RLG working machine 14 (stop S 1 ). After the placement, the bar code 13 described on the jig 11 is read out by the bar code reader 12 (stop S 2 ).
Thus, the computer 15 obtains a jig number from input bar code data, and retrieves the JIGNODB table 18 of the RLG database 17 by referring to the obtained jig number, and extracts a wafer number and a bar number (stop S 3 ).
Then, the WAFERDB table 19 of the RLG database 17 is retrieved by referring to these wafer number and bar number, and parameters inherent to the bar, a target value of MR height working, and working standards (errors) thereof are extracted from the table 19 (stop S 4 ).
Then, the RLG working process for lapping the ABS is started on the basis of the extracted data (step S 5 ). This RLG working process is carried out as follows. During lapping, resistance values of the RLG sensors are repeatedly (at a predetermined interval, for example, 10 seconds) detected and MR heights H M R at that time are calculated (step S 6 ). Then, bending of the bar is corrected to uniform MR heights in the respective portions of the bar, in response to the calculated values (step S 7 ). If the calculated MR heights H MR have reached to the target value, the Lapping is stopped (step S 8 and S 9 ). After the RLG working process is completed, finally measured resistance data R 1 and R 2 are stored in the WAFERDB table 19 (step S 10 ).
In this embodiment, the resistance values R 1 and R 2 of the first and second RLG sensors 54 and 55 are detected and MR heights are calculated from the detected resistance values. The MR height H MR is calculated by parameters R L and (C+S×W 1 ) inherent to the bar and by detected resistance data R 1 and R 2 , using the following expression;
H MR =( C+S×W 1 )/( R 1 −R L )
or
H MR =( C+S×W 1 )/( R 2 −R L ).
FIG. 6 schematically illustrates a flow of a taper working process in this embodiment which is carried out sequentially to the RLG working process shown in FIG. 4 .
After the RLG working process has been completed, a primary taper working (rough working) of the bar is carried out for a required time with the jig 11 attached to the RLG working machine 14 (step S 11 ).
Then, the jig 11 is detached from the RLG working machine 14 , and is placed on the chamfer length measuring device 21 to measure its chamfer length after the primary taper working (step S 12 ). Then, the bar code 13 of the jig 11 is read out by the bar code reader 12 (step S 13 ).
Thus, the computer 15 obtains a jig number from input bar code data, retrieves JIGNODB table 18 for the RLG database 17 by referring to the obtained jig number, and extracts a wafer number and a bar number (step S 14 ).
Then, the WAFERDB table 19 of the RLG database 17 is retrieved by referring to these wafer number and bar number, and working standard values of this bar are extracted from the table 19 (step S 15 ).
Then, the chamfer length is measured by the chamfer length measuring device 21 , and the measured data is stored in the WAFERDB table 19 (step S 16 ).
The jig 11 is then detached from the chamfer length measuring device 21 , and is placed on the RLG working machine 14 (step S 17 ). Thereafter, the bar code 13 of the jig 11 is read out again by the bar code reader 12 (step S 18 ).
Thus, the computer 15 obtains the jig number from input bar code data, retrieves JIGNODB table 18 for the RLG database 17 by referring the obtained jig number, and extracts the wafer number and bar number (step S 19 ).
Then, the WAFERDB table 19 for the RLG database 17 is retrieved by referring the wafer number and the bar number, and the measured data of the chamfer length of the bar and the standard values of the bar are extracted from the table 19 (step S 20 ).
From thus obtained measured data of the chamfer length, the standard values and the time period of the primary taper working (rough working), a required time period for a secondary taper working (accurate working) by which the chamfer length becomes a target value is calculated (step S 21 ).
The secondary working is then carried out on the basis of this calculated time period (step S 22 ). After the completion of the secondary working, the jig 11 is detached from the RLG working machine 14 (step S 23 ).
As explained above, since WAFERDB table 19 stores retrievable data in a unit of bar, the workpieces in one process can be moved to next process by the unit of bar. As a result, each process can be smoothly carried out causing dwell time between the processes to reduce.
Furthermore, since identification of the bar 10 to be worked is carried out by identifying the jig 11 to which the bar 10 is attached, the identification of the bar 10 to be worked is certain and easy, whereby the problem according to the conventional art that incorrect bar working processes are executed due to using of another bar data can be solved. In addition, since the identification of the bar 10 is carried out by using JIGNODB table 18 in which relationships of the wafer number, the bar number and the jig number are stored, the bar identification in each working process can be certainly and rapidly carried out. Therefore, working man-hour for retrieval or else is greatly decreased.
Furthermore, since the jig is identified by using a bar code, reading can be certainly carried out than in a case where other identification signs are used.
Alternatively, if a plurality of sets of a computer and a RLG working machine are in parallel connected to RLG database through a network of such as LAN, a working process such as a RLG working can be simultaneously carried out with respect to bars of one wafer.
Although in the above-mentioned embodiment, data is used in a unit of bar in the RLG working process and the taper working process, it is apparent that the same advantages will be obtained in other working processes and other processes other than the working processes such as a visual test process for a slider.
Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims. | A method for manufacturing a thin-film magnetic head includes a step of cutting a wafer into bars, each bar having a plurality of thin-film magnetic head sliders which are sequentially coupled with each other, a step of identifying the bar to be worked to generate an identification signal which indicates identity of the bar, a step of obtaining data of the bar in a unit of bar depending upon the identification signal, and a step of processing at least one working of the bar on the basis of the obtained data of the bar. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 13/488,160 filed Jun. 4, 2012 entitled “Bicycle Racing Apparatus”, currently pending, which claims the benefit of U.S. Provisional Patent Application 61/492,505, filed Jun. 2, 2011, also entitled “Bicycle Racing Apparatus” and U.S. Provisional Patent Application 61/570,093, filed Dec. 13, 2011, also entitled “Bicycle Racing Apparatus” all by the same inventor and all hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to articles of apparel and related devices that enable the rider of a bicycle to assume and maintain a more nearly ideal aerodynamic configuration as would be particularly beneficial to a rider participating in a bicycle racing event.
[0004] 2. Related Background Art
[0005] The technologies underpinning bicycle racing have evolved rapidly over the past few decades resulting in new materials and devices for increasing the speed and efficiency of the racing system comprising the machine and its rider. The primary aims of these development activities have been two-fold: 1) reducing the weight of a system element while maintaining minimum structural strength requirements and 2 ) reducing the aerodynamic drag of the racing system. In spite of these advances, the rider remains the single largest source of inefficiency, typically representing more than 60% of the total aerodynamic drag on the racing system. The bicycle itself typically represents only about 20% of the total drag, with the balance attributed to other mechanisms.
[0006] The physics of bicycle movement require that the aerodynamic drag force be proportional to the density of the surrounding fluid (air), the square of the velocity through the fluid, and the sum of the drag coefficients related to the rider and the bicycle. The drag coefficients are, in turn, related to the product of a dimensionless coefficient of drag that relates to the shape of an object and that object's frontal area exposed to the moving fluid stream. Thus, to reduce the aerodynamic drag force at a particular vehicle speed, one is led to reduce either or both of the frontal area and the coefficient of drag of the rider and the bicycle. Such has been the motivation behind the development of devices such as aerodynamically shaped frames, handle bars, wheels, brakes, etc. that act primarily to reduce the coefficient of drag of those elements of the bicycle. Similarly, the development of aerodynamically shaped helmets, skin suits, glasses and the like reduce the coefficient of drag of the rider.
[0007] Much improvement has been accomplished using these devices, but the nature of athletic competition is that all highly skilled bicyclists train to benchmarks set by recent competitions, and arrive at a new race with remarkably similar physical capabilities. Improvements of a few percentage points attributable to their equipment can easily make the difference between winning and losing an important competition. Consequently, there is an ongoing need for innovation in this area, and a focus on reducing the coefficient of drag of the rider would seem to be the most profitable direction.
[0008] The present invention comprises a suite of innovations that reduce the coefficient of drag of the bicycle rider by either directly improving his aerodynamic profile or by allowing the athlete to assume and maintain a more aerodynamically efficient riding position.
DISCLOSURE OF THE INVENTION
[0009] The elements of the present invention include two items of apparel that directly reduce the coefficient of drag of a bicycle rider and two devices that allow the rider to maintain a riding position that further reduces the coefficient of drag of the rider. The first of the items of apparel is a pair of bicycle racing shoes that includes an aerodynamic molding over the usual pedal coupling that is typically attached directly to the sole of the shoe. The molding directly reduces the coefficient of drag of the shoe and has the additional benefit of making it easier for the bicyclist to walk in the shoes without slipping and inflicting possible injury to the bicyclist. The second item of apparel is an inflatable body fairing worn on the bicyclist's chest area that directly reduces the coefficient of drag of the bicyclist's torso while in an aerodynamically efficient riding position. The fairing has the additional benefit of being capable of being inflated with water and food/electrolytes in separate compartments that can be used to nourish the bicyclist during the race with different fluids as desired.
[0010] The third device is a unique configuration for a riding goggle that incorporates a means of providing forward vision to allow the bicyclist to follow the race course and avoid obstacles while the bicyclist's head is lowered to assume a more aerodynamically efficient riding position and help prevent fatigue of the neck muscles. The fourth device is a unique vision system for bicycle racers that comprises a miniature, low power video camera attached to the rear surface of a racing helmet so as to provide a field of vision extending ahead of the racer when the racer's head is lowered into an aerodynamically efficient position. In a preferred embodiment, the image signal from the video camera is directed to a suitable display unit either wirelessly or by using suitable lightweight electronic cables. In one embodiment the display unit is a miniature video display such as typically used as a viewfinder in a modern electronic camera system that is directly attached to a specially modified racing eyewear so as to be within the bicyclist's direct field of vision. In another embodiment the display unit is a larger video display mechanically attached to the front frame of the bicycle so that it is within the field of view of the bicyclist when the bicyclist's head is lowered to assume a more aerodynamically efficient riding position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a bicycle rider in a conventional riding position.
[0012] FIG. 2 shows a bicycle rider in an improved riding position and also employing elements of the present invention.
[0013] FIG. 3 shows a side view of a conventional bicycle racing shoe.
[0014] FIG. 4 shows a bottom view of a conventional bicycle racing shoe.
[0015] FIG. 5 shows a side view of an improved bicycle racing shoe.
[0016] FIG. 6 shows a bottom view of an improved bicycle racing shoe.
[0017] FIG. 7 shows a frontal view of an embodiment of an inflatable body fairing.
[0018] FIG. 8 shows a side view of an embodiment of an inflatable body fairing.
[0019] FIG. 9 shows a side view of a different embodiment of an inflatable body fairing.
[0020] FIG. 10 shows a frontal view of an embodiment of an improved racing goggle.
[0021] FIG. 11 shows a side view of an embodiment of an improved racing goggle.
[0022] FIG. 12 shows a side view of an embodiment of an improved racing goggle as worn.
[0023] FIG. 13 shows a frontal view of a different embodiment of an improved racing goggle.
[0024] FIG. 14 shows a side view of a different embodiment of an improved racing goggle.
[0025] FIG. 15 shows a side view of a different embodiment of an improved racing goggle as worn.
[0026] FIG. 16 shows a side view of a first embodiment of the vision system wherein video camera and video display elements of the invention are both mounted on a bicyclist's helmet.
[0027] FIG. 17 shows a front view of the helmet-mounted video display element of the invention shown in FIG. 16 .
[0028] FIG. 18 shows a side view of a second embodiment of the vision system including helmet-mounted video camera and eyewear-mounted video display elements of the invention.
[0029] FIG. 19 shows a front and right side view of the embodiment of the eyewear-mounted video display element of the invention shown in FIG. 18 .
[0030] FIG. 20 shows a side view of a third embodiment of the invention in which the video display is mounted on the bicycle frame.
DETAILED DESCRIPTION
[0031] FIG. 1 depicts the prior art and shows a rider 100 on a bicycle 101 in a conventional racing configuration in which the rider's head 102 must be raised most of the time to provide forward vision along line of sight 103 to follow the race course and to avoid collision with obstacles. When the head is raised, the chest is typically also raised, thereby increasing the effective frontal area 104 of the torso and the coefficient of drag of the rider. Conventional bicycle racing shoes 105 have flat soles that generate turbulence that contributes to the coefficient of drag of the rider.
[0032] FIG. 2 shows a rider 100 on a bicycle 101 in a more aerodynamically efficient riding position wherein the rider's head 200 and torso are lowered to reduce the effective frontal area and achieve a configuration having a smaller coefficient of drag. The conventional racing configuration is shown in dotted lines for reference. The bicyclist is wearing special eyewear 201 that provides a forward line of sight 202 while in this riding position in order for the bicyclist to follow the race course and avoid obstacles. Additionally, the bicyclist is wearing an inflatable body fairing 203 that reduces the coefficient of drag contributed by the bicyclist's torso, and racing shoes having aerodynamically shaped soles that reduce the coefficient of drag contributed by the shoes.
[0033] FIGS. 3 and 4 illustrate the prior art in bicycle racing shoes in which pedal coupling members 301 are attached directly to the flat soles 302 of each shoe. The flat soles generate turbulence that increases the coefficient of drag contributed by the shoes. Additionally, the metal pedal coupling members 301 can make footing treacherous while attempting to walk in these shoes, resulting in slipping and potential injury from a fall.
[0034] FIGS. 5 and 6 show the improved racing shoe in which a molding compound is used to form an aerodynamically shaped surface 500 on at least the front half of the sole 302 around the pedal coupling member 301 . Nonlimiting examples of the molding compound are materials such as an epoxies, crepe sole shoe materials, urethane compounds and room temperature vulcanizing silicone compounds. This aerodynamically shaped surface reduces the coefficient of drag contributed by the shoes and further makes it easier to walk in the shoes without risking injury due to slipping since the molding compound completely surrounds the metal pedal coupling member 301 .
[0035] FIG. 7 shows a frontal view of an inflatable body fairing used to provide an enhanced aerodynamic shape that reduces the coefficient of drag contributed by the bicyclist's torso. The body fairing includes a central inflatable section 701 and separate side inflatable sections on the left 702 and right 703 sides of the bicyclist's frontal torso, each of which is inflated through a separate integrated coupling and valve assembly 704 , 705 , and 706 . Although nominally inflated with air, the sections 701 - 703 can alternatively be inflated with water and food/electrolytes that can be used to nourish the bicyclist during the race. In the figure, the central section 701 is equipped with an anti-splash opening having a quick fill cap 708 that allows for rapid filling of the section with water or electrolyte/food material during a race. FIG. 8 shows a left side view of one embodiment of the body fairing, illustrating the reduced thickness of the side section 702 compared with central section 701 . The body fairing is attached to the torso using shoulder straps 707 connected at the top of the body fairing that attach to waist strap 709 connected at the bottom of the fairing and is intended to be worn beneath a conventional racing shirt.
[0036] FIG. 9 shows a left side view of an alternate embodiment that includes rear central section 901 and rear side sections, of which rear left side section 902 is shown. The body fairing is attached to the torso using waist straps 903 and is intended to be worn beneath a conventional racing shirt.
[0037] FIGS. 10 and 11 show frontal and right side views, respectively, of a special bicycle racing goggle designed to provide a rectified forward vision while the bicyclist's head faces downward in the more aerodynamically efficient riding position shown in FIG. 2 . The goggle includes right 1001 and left 1002 transparent lenses, and an optical device 1003 in the form of a wide-angle lens implemented as a Fresnel lens and integrated into at least one of the lenses 1001 and 1002 . FIG. 12 shows a right side view the racing goggle of FIGS. 10 and 11 in an as-worn configuration and illustrates the forward line of sight 1201 provided by the Fresnel lens 1003 .
[0038] FIGS. 13 and 14 show frontal and right side views, respectively, of an alternate embodiment of a special bicycle racing goggle designed to provide a measure of forward vision while the bicyclist's head faces downward in the more aerodynamically efficient riding position shown in FIG. 2 . The goggle includes right 1301 and left 1302 transparent lenses, and an optical device 1303 in the form of a prism integrated into at least one of the lenses. FIG. 15 shows a right side view the racing goggle of FIGS. 13 and 14 in an as-worn configuration and illustrates the forward line of sight 1501 provided by the prism 1303 which angle can be adjusted through an adjustment range 1500 .
[0039] FIG. 16 shows an embodiment comprising a miniature battery-operated video camera 1600 mounted to a racing helmet 1601 to provide a forward field of view 1602 when the racer's head is lowered into an aerodynamically efficient position. The video camera is constructed using any of the available low power imager chips that are used in portable cellular “smart” telephone units, for example. In a non-limiting example, the image signal from the camera 1603 is wirelessly communicated using additional communications hardware and software enclosed in the camera housing to a battery-operated receiver/processor 1604 also mounted on the helmet. The received image is displayed on a miniature video display device 1606 that presents the forward scene directly to the bicyclist's eye. The miniature video display device is a low-power unit such as is typically used as a viewfinder in a modern electronic camera system. The bicyclist wears conventional racing eyewear 1605 .
[0040] FIG. 17 shows a front view of the helmet-mounted video display embodiment shown in FIG. 16 in order to more clearly illustrate the placement of the receiver/processor 1604 and video display 1606 elements.
[0041] FIG. 18 shows an embodiment of the present invention comprising a miniature battery-operated video camera 1600 mounted to a racing helmet 1601 to provide a forward field of view 1602 when the racer's head is lowered into an aerodynamically efficient position. The video camera is constructed using any of the available low power imager chips that are used in portable cellular “smart” telephone units, for example. In a non-limiting example, the image signal from the camera 1603 is wirelessly communicated using additional wireless communications link hardware and software enclosed in the camera housing to a battery-operated receiver/processor 1604 mounted on special racing eyewear 1605 . The received image is displayed on a miniature video display device 1606 that presents the forward scene directly to the bicyclist's eye. The miniature video display device is a low-power unit such as is typically used as a viewfinder in a modern electronic camera system.
[0042] FIG. 19 shows frontal and right side views of the special racing eyewear depicted in FIG. 16 . The eyewear includes right 1901 and left 1902 lenses, a battery-operated receiver/processor 1604 and a miniature video display screen 1606 mounted in front of one of the lenses.
[0043] FIG. 20 shows an alternative embodiment of the present invention including a rider 100 positioned on a bicycle 101 in a more aerodynamically efficient riding position wherein the rider's head and torso are lowered to reduce the effective frontal area and achieve a configuration having a smaller coefficient of drag, wherein the miniature video camera 2000 attached to the bicyclist's racing helmet 2001 covers a forward field of view 2002 . In this embodiment, the image signal from the video camera is communicated to a battery-operated video display device 2003 which is mounted to the frame of the bicycle 101 in such a position as to provide direct viewing of the forward scene by the rider 100 . The frame-mounted video display device can be constructed using a back-illuminated liquid-crystal display (LCD) screen as is used in portable computers, tablet computers and “smart” cellular telephone units. In another embodiment of the invention (not shown) the video camera is also affixed to the frame of the bicycle. | The present invention comprises a suite of innovations that reduce the coefficient of drag of a bicycle rider. The innovations include aerodynamically shaped bicycle riding shoes, an inflatable body fairing worn on the bicyclist's chest area that directly reduces the coefficient of drag of the bicyclist's torso while in an aerodynamically efficient riding position, and a riding goggle and a portable imaging system that reduce the coefficient of drag of a bicycle rider by allowing the athlete to assume and maintain a more aerodynamically efficient riding position. | 0 |
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/141,917, filed Jun. 1, 2005, now U.S. Pat. No. 7,936,755, which is a divisional application of U.S. application Ser. No. 10/044,989, filed Jan. 15, 2002, now U.S. Pat. No. 6,957,281.
RESERVATION OF COPYRIGHT
This patent document contains information subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent, as it appears in the U.S. Patent and Trademark Office files or records but otherwise reserves all copyright rights whatsoever.
BACKGROUND
Aspects of the present invention relate to communications. Other aspects of the present invention relate to packet based communication.
Data exchange between independent network nodes is frequently accomplished via establishing a “session” to synchronize data transfer between the independent network nodes. For example, transmission control protocol/Internet protocol (TCP/IP) is a popular implementation of such a session method. Data transferred over such an established session is usually fragmented or segmented, prior to transmission on a communication media, into smaller encapsulated and formatted units. In the context of input and output controllers such as Ethernet Media Access Controllers (MACs), these encapsulated data units are called packets. Since packets are originally derived from data of some communication session, they are usually marked as “belonging” to a particular session and such marking is usually included in (or encapsulated in) the packets. For instance, in a TCP/IP session, network addresses and ports embedded in the packets are used to implement per-packet session identification.
When packets of the same session are received at a destination, they may be temporarily stored in a buffer on an I/O controller prior to being further transferred to a host system where the packets will be re-assembled or defragmented to re-create the original data. The host system at a destination may be a server that may provide network services to hundreds or even thousands of remote network nodes.
When a plurality of network nodes simultaneously access a common network resource, packets from a communication session may be shuffled with packets from hundreds of other different sessions. Due to this unpredictable data shuffling, a host system generally processes each received packet individually, including identifying a session from the received packet and accordingly identifying a corresponding session on the host system to which the received packet belongs. There is an overhead on the host system associated with such processing. In addition, when a data stream is transmitted continuously under a communication session, each received packet, upon arriving at the host, may need to be incorporated into the existing data stream that constitutes the same session. Using newly arrived packets to update an existing session is part of the re-assembly or defragmentation. This further increases the overhead on the host system. Furthermore, the overhead may increase drastically when there are a plurality of concurrent communication sessions. High overhead degrades a host system's performance.
When notified of the arrival of a packet, a host system processes the packet, determines the packet's underlying session, and updates an existing session to which the arrived packet belongs. Processing one packet at a time enables the host system to better handle a situation in which packets from different sessions are shuffled and arrive in a random manner. It does not, however, take advantage of the fact that packets are often sent in bursts (or so called packet troops or packet trains).
There have been efforts to utilize such burst transmission properties to improve performance. For example, packet classification techniques have been applied in routing technology that exploits the behavior of packet train to accelerate packet routing. Packet classification techniques have also been applied for other purposes such as quality of service, traffic metering, traffic shaping, and congestion management. Such applications may improve the packet transmission speed across networks. Unfortunately, they do not impact a host system's (at the destination of the transmitted packets) capability in re-assembling the received packets coming from a plurality of underlying communication sessions.
A gigabit Ethernet technology known as ‘jumbo frames’ attempted to improve the performance at a destination. It utilizes “jumbo frames” that increases the maximum packet size from 1518 bytes (the Ethernet standard size) to 9022 bytes. The goal is to reduce the data units transmitted over the communications media and subsequently a network node may consume fewer CPU resources (overhead) for the same amount of data-per-second processed when “jumbo frames” are used. However, data units that are merged to form a larger unit are not classified. As a consequence, at destination, a host system may still need to classify packets before they can be used to re-assemble the data of specific sessions. Due to that, the overhead used to correctly recover the original data streams may still remain high.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is further described in terms of exemplary embodiments, which will be described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
FIG. 1 depicts a high level architecture which supports classification based packet bundle generation and transfer between an I/O controller and a host, according to embodiments of the present invention;
FIG. 2 depicts the internal structure of an I/O controller, in relation to a host, that is capable of grouping packets into a bundle based on classification, according to embodiments of the present invention;
FIG. 3 shows an exemplary construct of a packet bundle descriptor, according to an embodiment of the present invention;
FIG. 4 shows an exemplary content of a packet bundle descriptor, according to an embodiment of the present invention;
FIG. 5 depicts the internal structure of a packet grouping mechanism, according to an embodiment of the present invention;
FIG. 6 is an exemplary flowchart of a process, in which a packet bundle is generated based on packet classification and transferred from an I/O controller to a host for processing, according to embodiments of the present invention;
FIG. 7 is an exemplary flowchart of an I/O controller, according to an embodiment of the present invention; and
FIG. 8 is an exemplary flowchart of a host, according to an embodiment of the present invention.
DETAILED DESCRIPTION
The processing described below may be performed by a properly programmed general-purpose computer alone or in connection with a special purpose computer. Such processing may be performed by a single platform or by a distributed processing platform. In addition, such processing and functionality can be implemented in the form of special purpose hardware or in the form of software being run by a general-purpose computer. Any data handled in such processing or created as a result of such processing can be stored in any memory as is conventional in the art. By way of example, such data may be stored in a temporary memory, such as in the RAM of a given computer system or subsystem. In addition, or in the alternative, such data may be stored in longer-term storage devices, for example, magnetic disks, rewritable optical disks, and so on. For purposes of the disclosure herein, a computer-readable media may comprise any form of data storage mechanism, including such existing memory technologies as well as hardware or circuit representations of such structures and of such data.
FIG. 1 depicts a high level architecture 100 that supports classification based packet bundle generation and transfer between an I/O controller 110 and a host 140 , according to embodiments of the present invention. Upon receiving packets, the I/O controller 110 activates a classification based packet transferring mechanism 120 to classify received packets according to some classification criterion, group classified packets into packet bundles, and then transfer the packet bundles to the host 140 at appropriate times. Upon receiving a packet bundle, the host 140 processes the packet bundle as a whole.
A packet bundle 130 is transferred from the I/O controller 110 to the host 140 via a generic connection. The I/O controller 110 and the host 140 may or may not reside at a same physical location. The connection between the I/O controller 110 and the host 140 may be realized as a wired connection such as a conventional bus in a computer system or a peripheral component interconnect (PCI) or as a wireless connection.
The classification-based packet transferring mechanism 120 organizes packets into packet bundles, each of which may comprise one or more packets that are uniform with respect to some classification criterion. For example, the classification-based packet transferring mechanism 120 may classify received packets according to their session numbers. In this case, packets in a single packet bundle all have the same session number.
An optional “classification ID” may be assigned to this packet bundle and provided to the host. The classification-based packet transferring mechanism 120 may classify received packets into one of a fixed number of sessions. If the number of sessions being received exceeds the number of sessions that the classification-based packet transferring mechanism 120 can indicate, one or more sessions may be marked with the same session identification.
When the packet bundle 130 is transferred to the host 140 , a packet bundle descriptor may also be transferred with the packet bundle 130 that specifies the organization of the underlying packet bundle. Such a packet bundle descriptor may provide information such as the number of packets in the bundle and optionally the session number of the bundle. The descriptor may also include information about individual packets. For example, a packet bundle descriptor may specify the length of each packet. The information contained in a packet bundle descriptor may be determined based on application needs.
When a packet bundle is constructed from classified packets, the classification-based packet transferring mechanism 120 determines an appropriate timing to transfer the packet bundle. When there are a plurality of packet bundles ready to be transferred, the classification-based packet transferring mechanism 120 may also determine the order in which packet bundles are transferred according to some pre-specified conditions. For example, the classification based packet transferring mechanism 120 may determine the order of transferring based on the priority tagging of the underlying packets. It may schedule a packet bundle whose packets have a higher priority to be transferred prior to another packet bundle whose packets have a lower priority. The classification based packet transferring mechanism 120 may also transfer the packet bundles into multiple, separate, and predefined receive queues based on the classification and/or priority of the packet bundles.
FIG. 2 depicts the internal structure of the I/O controller 110 in relation to the host 140 , according to embodiments of the present invention. The I/O controller 110 comprises a packet receiver 210 , a packet queue 220 , a packet queue allocation mechanism 230 , and the classification-based packet transferring mechanism 120 which includes a packet classification mechanism 240 , a transfer scheduler 250 , and a packet grouping mechanism 260 . The packet queue allocation mechanism 230 may allocate one or more packet queues as storage space for received packets. Upon intercepting incoming packets, the packet receiver 210 buffers the received packets in the packet queue 220 .
The packet queue 220 may be implemented as a first in and first out (FIFO) mechanism. With this implementation, packets in the FIFO may be accessed from one end of the queue (e.g., front end) and the incoming packets are buffered from the other end of the queue (e.g., rear end). In this way, the packet that is immediately accessible may be defined as the one that has been in the queue the longest. When the packet receiver 210 intercepts incoming packets, it populates the received packets in the packet queue 220 by inserting the packets to the rear end of the packet queue 220 . The packet queue 220 may also be realized as a collection of FIFOs.
The packet queue 220 may be realized either within the I/O controller 110 (as shown in FIG. 2 ) or within the memory of the host 140 (not shown). The packet queue 220 provides a space for packet look ahead (will be discussed later) and for manipulating the received packets, including re-ordering the packets according to some classification criterion. The size of the packet buffer 220 may be determined based on application needs and such system configuration factors as, for example, speed requirements.
The classification-based packet transferring mechanism 120 may access the received packets from the front end of the packet queue 220 . To classify received packets according to, for example, session numbers, the classification-based packet transferring mechanism 120 may dynamically determine a session number for classification purposes from a buffered packet that is immediately accessible in the front of the packet queue 220 . Such a session number may be extracted from the buffered packet.
With a classification criterion (e.g., a session number), the packet classification mechanism 240 may look ahead of the received packets buffered in the packet queue 220 and classifying them according to the session number. The size of the packet queue 220 may constrain the scope of the classification operation how far to look ahead in the packet stream) and may be determined based on particular application needs or other system configuration factors. For instance, assume an I/O controller is operating at a speed of one gigabits-per-second, then one (1) 1500 byte packet can be received every 12 usec. Further assume that an inter-packet-gap is around 24 usec between packets of the same network session. Under such operational environment, the size of the packet queue 220 may be required to be big enough to store and classify at least four (4) 1500 byte packets (a total of 6000 bytes) simultaneously to support the speed requirement.
As mentioned earlier, the packet queue 220 may be realized differently. For example, it may be implemented as an on-chip FIFO within the I/O controller 110 . In this case, the above described example will need a packet buffer (or FIFO) of at least 6000 bytes. Today's high-speed Ethernet controllers can adequately support 32K or larger on-chip FIFOs.
When the packet queue 220 is implemented within the I/O controller 110 , the packet classification mechanism 240 in the classification-based packet transferring mechanism 120 looks ahead and classifies the packets within the FIFO on the I/O controller. According to the classification outcome, the order of the received packets may be re-arranged in the packet queue 220 (e.g., arrange all the packets with a same session number in a sequence). To deliver such processed packets to the host 140 , the packets are retrieved from the queue and then sent to the host 140 .
If the packet queue 220 is realized on the host 140 , the packet classification mechanism 240 may perform classification within the memory of the host 140 . In this case, when the classification is done, to deliver the processed packets to the host 140 for further processing, the processed packets may not need to be moved and the host 140 may be simply notified of the processed packets in the memory.
When classification is complete, all packets that are classified as a single group have, for example, the same session number and are arranged according to, for instance, the order they are received. This group of packets may be delivered to the host 140 as one unit identified by the session number. The transfer scheduler 250 may determine both the timing of the deliver and form (sending the packets from the I/O controller 110 to the host 140 or sending simply a notification to the host 140 ) of the delivery. The transfer scheduler 250 may decide the delivery timing according to the priority associated with the packets, wherein such priority may be tagged in the packets. A packet group with a higher priority may be delivered before another packet group that has a lower priority.
When there are multiple FIFOs, the transfer scheduler 250 may also schedule the transfer of classified packets from different FIFOs also through priority scheduling. In addition, an on-going transfer of a group of packets that has lower priority packets may be pre-empted so that another group of packets that has higher priority packets can be transferred to the host 140 in a timely fashion. The transfer of the pre-empted group may be restored after the transfer of the higher priority group is completed.
The packet receiver 210 and the mechanisms such as the packet classification mechanism 240 and the packet grouping mechanism 260 may share the resource of the packet queue 220 . The process of populating the buffered packets and the process of processing these packets (e.g., classifying and grouping) may be performed asynchronously. For example, the packet receiver 210 may push received packets into a FIFO and the packet classification mechanism 240 may pop packets from the same FIFO.
When a transfer schedule is determined, the transfer scheduler 250 notifies the packet grouping mechanism 260 , which subsequently generates a packet bundle 130 with a corresponding packet bundle descriptor. The packet bundle 130 is a collection of packets that are uniform in the sense that they all have the same characteristic with respect to some classification criterion (e.g., all have the same session number, or hash result of session number or other fields). The packets in a packet bundle may be arranged in the order they are received. The corresponding packet bundle descriptor is to provide information about the underlying packet bundle. Such information facilitates the host 140 to process the underlying packet bundle.
FIG. 3 shows an exemplary construct 300 of a packet bundle descriptor, according to an embodiment of the present invention. A packet bundle descriptor may comprise an overall bundle descriptor 310 and a collection of packet descriptors 320 , 330 , . . . , 340 . The bundle descriptor 310 may include information about the organization of the underlying packet bundle such as the number of packets. A packet descriptor may provide information related to each individual packet such as the packet length.
FIG. 4 shows exemplary content of the overall bundle descriptor 310 , according to an embodiment of the present invention. The overall bundle descriptor 310 may specify the number of packets 410 contained in the underlying packet bundle and some identifying characteristics associated with the packet bundle such as a session identification 450 and a priority level 480 . The host 140 may use such information during processing. For example, the host 140 may update an existing session using a received packet bundle according to the session number provided in the corresponding packet bundle descriptor. Based on the number of packets 410 , the host 140 may, for instance, update the corresponding existing session with a correct number of total number of packets without having to process each individual packets in the bundle.
The packet descriptors 320 , 330 , . . . , 340 are associated with individual packets in a packet bundle. They may include such information as packet identification (ID) 420 , packet status 425 , packet length 430 , packet buffer address 435 , or out-of-order indicator 440 . For example, the packet ID 420 identifies a packet in a packet bundle using a sequence number identifying the position of the packet in the bundle.
To generate a packet bundle and its corresponding packet bundle descriptor, the packet grouping mechanism 260 may invoke different mechanisms. FIG. 5 illustrated an exemplary internal structure of the packet grouping mechanism 260 . It includes a packet bundle generator 510 and a packet bundle descriptor generator 520 . The former is responsible for creating a packet bundle based on classified packets and the latter is responsible for constructing the corresponding packet bundle descriptor.
The transfer scheduler 250 delivers a packet bundle to the host 140 with proper description at an appropriate time. The delivery may be achieved by notifying the host 140 that a packet bundle is ready to be processed if the packet queue 220 is implemented in the host's memory. Alternatively, the transfer scheduler 250 sends the packet bundle to the host 140 . Whenever a packet bundle is delivered, the transfer scheduler 250 sends the corresponding packet bundle descriptor 300 to the host 140 .
The host 140 comprises a notification handler 270 , a packet bundle processing mechanism 280 , and a session update mechanism 290 . The notification handler 270 receives and processes a notification from the I/O controller 110 . Based on the notification, the packet bundle processing mechanism 280 further processes the received packet bundle. Since all the packets within a packet bundle are similar, the packet bundle processing mechanism 280 treats the bundle as a whole. Furthermore, the session update mechanism 290 utilizes the received packet bundle by its entirety to update an existing session.
FIG. 6 is an exemplary flowchart of a process, in which a packet bundle is generated based on packet classification and transferred from the I/O controller 110 to the host 140 , according to embodiments of the present invention. Packets are received first at 610 . Such received packets are populated or buffered at 620 in the packet queue 220 . The buffered packets are subsequently classified at 630 . The transfer scheduler 250 then determines, at 640 , which classified group of packets is to be transferred next.
According to a transfer schedule, a packet bundle and its corresponding packet bundle descriptor are generated, at 650 , based on classified packets and then sent, at 660 , to the host 140 . Upon receiving, at 670 , the packet bundle and the corresponding packet bundle descriptor, the host 140 processes, at 680 , the packet bundle according to the information contained in the corresponding packet bundle descriptor.
FIG. 7 is an exemplary flowchart of the I/O controller 110 , according to an embodiment of the present invention. Packets are received first at 710 and populated, at 720 , in the packet queue 220 . To classify buffered packets, a session number is identified, at 730 , as a dynamic classification criterion. Based the classification criterion, the packet classification mechanism 240 classifies the buffered packets at 740 . The transfer scheduler 250 then schedules, at 750 , to transfer a packet bundle according to some pre-defined criterion. When a transfer decision is made, the packet grouping mechanism 260 generates, at 760 and 770 , a packet bundle based on classified packets and a corresponding packet bundle descriptor. Such generated packet bundle and its descriptor are then transferred, at 780 , to the host 140 .
FIG. 8 is an exemplary flowchart of the host 140 , according to an embodiment of the present invention. Upon receiving a packet bundle and its corresponding packet bundle descriptor at 810 , the host 140 parses, at 820 , the packet bundle descriptor to extract useful information. To update an appropriate session using the packets in the received packet bundle, the host 140 identifies, at 830 , the session number of the packet bundle. Based on the session number, the host 140 updates an existing session using the received packet bundle.
While the invention has been described with reference to the certain illustrated embodiments, the words that have been used herein are words of description, rather than words of limitation. Changes may be made, within the purview of the appended claims, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described herein with reference to particular structures, acts, and materials, the invention is not to be limited to the particulars disclosed, but rather can be embodied in a wide variety of forms, some of which may be quite different from those of the disclosed embodiments, and extends to all equivalent structures, acts, and, materials, such as are within the scope of the appended claims. | A system includes logic to store multiple descriptors, each of the multiple descriptors to be associated with a different set of multiple Transmission Control Protocol/Internet Protocol (TCP/IP) packets received by the network controller, each of the multiple descriptors including a count of the number of packets in the set of multiple packets associated with a respective descriptor. For each of the respective receive packets, the system determines a one of the multiple descriptors based on the network source address, network destination address, source port, and destination port of the respective packet; includes the respective packet in the set of multiple packets associated with the determine one of the multiple descriptors; and updates the one of the multiple descriptors by incrementing the count of the number of packets in the set of multiple packets; and provides data from within the packets to the host. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to protective armguards, and more specifically relates to a protective forearm/elbow guard for archers in order to protect the archer against injury.
Archers customarily wear a forearm guard, particularly beginning archers who are prone to improperly draw back or release the bowstring. Even the slightest misalignment of the bowstring when released may cause it to slap against the elbow or forearm with a great deal of force so as to inflict considerable pain if not injury. Heretofore, forearm protectors have been designed for attachment along the forearm portion below the elbow. Typically, such protectors have a fairly solid but somewhat flexible covering or pad which is releasably fastened at spaced intervals along the forearm by flexible straps so that the covering comformably extends along the inner fleshy portion of the forearm upwardly from the palm of the hand. While such guards afford some protection against injury, they do not protect the elbow portion which in many cases is subject to the same type of injury when the bowstring is improperly released, and this is especially true with respect to the side of the ulna at its connection to the humerus. Constant bending or movement of the arm has in the past discouraged any type of elbow protector or guard and it is therefore important that any such type of guard not impose a restriction on free movement of the arm, for example, in reloading the bow or in flexing or bending of the arm for other purposes.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide for a novel and improved arm guard to prevent accidental injury to the arm and elbow in archery.
It is another object of the present invention to provide an arm guard for archers which can be easily attached to and removed from the forearm directly behind the hand holding the bow while affording complete protection from accidental injury both to the forearm and elbow when the bowstring is improperly released.
It is a further object of the present invention to provide a protective shield for archers which is of simplified construction, economical to manufacture and is readily attachable to the forearm of the archer to protect both the forearm and the elbow from accidental injury without limiting free movement or bending of the arm.
In accordance with the present invention, a preferred form of arm guard for archers has been devised in which a covering or shield is releasably attached along the inside or fleshy portion of the forearm so as to closely conform to the configuration of the forearm, and the covering includes an upward continuation in the form of a generally concave extension which overlies and closely conforms to the side of the elbow without attachment to the arm. In this way, the elbow shield is free to follow movement of the rest of the arm guard when the arm is bent or twisted; and when the arm is straightened the elbow shield will automatically return into position overlying the side of the elbow facing the bowstring so as to shield it against accidental injury which might otherwise be caused by improper release of the bowstring.
The above and other objects, advantages and features of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of preferred and alternate forms when taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view illustrating placement of the arm guard on an archer's forearm in use.
FIG. 2 is a plan view of the preferred form of arm guard in accordance with the present invention.
FIG. 3 is an end view of the arm guard shown in FIG. 2; and
FIG. 4 is an end view of a modified form of arm guard in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in more detail to the drawings, and as a setting for the present invention, FIG. 1 illustrates the manner of placement of an arm guard 10 on the forearm of an archer so as to be disposed in facing relation to the path of travel of a bowstring 12 in shooting an arrow 14. The bow 16 is grasped so that the bowstring 12, if improperly released, has a tendency to spring forward with a great deal of force against the inside or fleshy portion of the forearm as designated at 18 as well as the inner side of the elbow 20. By "inner side" is meant that portion of the arm or elbow which normally would face inwardly toward the body when the arm is in a relaxed state or extending downwardly along the body with the palm facing inwardly toward the body. As illustrated, when the left hand of a right-handed archer grasps the bow, the inner portion of the forearm and the elbow of the left arm is exposed to possible injury when the bowstring 12 is improperly released. This is particularly true with respect to beginning archers who do not maintain proper alignment of the bowstring in drawing it rearwardly as a preliminary to shooting the arrow. If the bowstring 12 is misaligned somewhat when the arrow is released, it will tend to snap or slap against the exposed portion of the arm with a great deal of force.
It is therefore highly desirable to shield both the arm and elbow against such possibility of injury but to do so in a way that will permit complete freedom of bending or twisting of the arm. To this end, a preferred form of arm guard 10 has been devised as shown in more detail in FIGS. 2 and 3 and is seen to comprise a main body portion 30 having an outer shield 32 composed of a tough but somewhat flexible material such as leather and an inner padding 34 which is suitably composed of a fabric or spongy, resilient material if desired and which is stitched along its outer periphery to the outer peripheral edge of the shield 32 as designated at 35. Preferably, the main body is contoured to conform to the tapered configuration of the forearm from a point below the elbow joint down to the wrist and therefore has a relatively wide portion 38 merging or tapering downwardly, or forwardly, as defined by the inwardly curving or concave side edges 40 and increasing somewhat in width at side portions 42 then once again tapering forwardly as defined by the side edges 44 into a forward rounded terminal end 45. An important feature of the present invention resides in the upper longitudinal extension 48 of the arm guard 10 which is formed as an upwardly convergent continuation of the wider portion 38 of the arm guard 10. Specifically, the wider portion converges inwardly into a neck defined by the inwardly curving side edges 50 and a somewhat enlarged rounded cap or convex head 52. As shown, the extension 48 is correspondingly constructed of the same material as the outer shield 32 and inner padding 34 of the main body portion and in the preferred form as shown is of one-piece construction. In addition, medial, longitudinally extending seams 54 and 55 are seen to extend in closely spaced relation to one another along the entire extent of the arm and elbow guard, which seams join the inner padding 34 to the outer shield 32 so as to more closely unite the two layers together.
Although the arm guard may normally lay somewhat flat when in a relaxed condition, it is of sufficient flexibility that when applied to the arm it has the ability to conform to the rounded configuration of the forearm in the manner shown in FIG. 3. In addition, the upper extension 48 is most desirably preshaped to have a slight concavity in inward facing relation to the elbow so as to snugly fit around the elbow joint and specifically at the juncture of the ulna, or larger bone of the forearm, to the humerus. In this relation, the main body portion 30 of the arm guard 10 is dimensioned so that at its wider portions 38 and 42 it will embrace or surround substantially one-half of the forearm.
In order to releasably attach the main body portion to the forearm, fastening means in the form of flexible straps 60 and 61 are sewn or otherwise connected to the wider portions 38 and 42 as shown and have complementary fastener elements at their opposite free ends. Thus, each strap 60 may suitably include a slotted or female fastener 62 which is adapted to receive a hook end portion 64 of a male fastener 65 on the strap 61. In addition, the strap 61 may be provided with a conventional type of length adjuster 66.
A modified form of invention is illustrated in FIG. 4 in which the main body portion 30 and upper extension 48 are formed in a manner corresponding to that described with reference to the preferred form and accordingly like parts are correspondingly enumerated. However, in the modified form of fastener as illustrated in FIG. 4 spring-like bands or clips 70 are employed as releasable fasteners in place of the straps 60 and 61 illustrated in FIGS. 2 and 3. Although not specifically shown, each band or clip 70 is of a width corresponding to that of the straps 60 and 61, and each is composed of a strong, durable plastic or spring steel material of limited resiliency which is relatively thin and of generally oval-shaped configuration and terminating in spaced apart outwardly bent or rounded terminal ends 72. Further, each band or clip 70 is embedded in the main body portion of the arm guard so as to extend continuously in a lateral direction between the inner padding 34 and outer shield 32; and in a conventional manner may be positioned in fixed relation by suitable stitching, not shown, between the padding 34 and shield 32 along opposite side edges of each band or clip. In the modified form, the spring clips greatly facilitate placement of the arm guard by spreading the free terminal ends 72 and forcing over the forearm until they spring back in place so as to position the arm guard in the relationship to the arm as illustrated in FIG. 1.
Both with respect to the preferred and modified forms of invention described, it is emphasized that the specific configuration of the main body portion as well as the fasteners may be varied or altered without departing from the scope of the present invention, although the specific form of main body portion as described lends itself particularly well for use in combination with the upper extension shield 48. Further, the main body portion 32 and upper extension 48 may be composed of various materials in achieving the desired objectives and features of the present invention. It is therefore to be understood that various modifications and changes may be made in the construction and arrangement of elements comprising preferred and alternate forms of the present invention without departing from the spirit and scope thereof and defined by the appended claims. | A protective guard for archers is adapted to be releasably and conformably fastened around the archer's forearm directly behind the hand which holds the bow with a protective strip of material extending upwardly along the forearm and having an upper free continuation which overlies a portion of the elbow when the arm is straightened so as to prevent accidental injury to the arm and elbow if the bowstring is improperly released. | 5 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to cryogenic refrigerators, in particular, GM type pulse tube refrigerators. This type of refrigerator is comprised of a compressor unit that is connected by gas lines to an expander unit, commonly referred to as a cold-head. Two-stage GM type pulse tubes running at low speed are typically used for applications below about 20 K. It has been found that best performance at 4 K has been obtained with the pulse tube shown in FIG. 9 of U.S. Pat. No. 6,256,998. This design has six valves which open and close in the sequence shown in FIG. 11 of that patent. It contains a good description of the mechanism for producing refrigeration at very low temperatures and the important role that the valves and buffer volumes play in shaping the P-V diagram, FIG. 10, to maximize the refrigeration produced per cycle. The relationship between the displacement of the gas and the cycling of the pressure that is seen in the P-V diagram is usually referred to as phase shifting.
[0002] The first pulse tube refrigerator was described by W. E. Gifford in U.S. Pat. No. 3,237,421. A significant improvement in performance was made by E. I. Mikulin, A. A. Tarasow and M. P. Shkrebyonock, ‘ Low temperature expansion ( orifice type ) pulse tube ’, Advances in Cryogenic Engineering, Vol. 29, 1984, p. 629-637 in 1984, when they added an orifice and buffer volume to the warm end of the pulse tube. This improved the phase shifting. S. Zhu and P. Wu, ‘ Double inlet pulse tube refrigerators: an important improvement ’, Cryogenics, vol. 30, 1990, p. 514, made a further improvement by adding a second orifice between the warm end of the pulse tube and the inlet to the regenerator. The application of the “double-orifice” principal to a two-stage pulse tube enabled the production of refrigeration below 4 K. Production of refrigeration below 4 K has also been achieved by means of a “four-valve” pulse tube as described in U.S. Pat. No. 5,335,505 and U.S. Pat. No. 5,412,952. The first patent describes single stage pulse tubes and the second describes two-stage pulse tubes. Phase shifting is achieved by the timing of opening and closing the valves between the warm ends of the pulse tubes and the lines to and from the compressor relative to the timing of the valves between the warm end of the regenerator and the lines to and from the compressor. U.S. Pat. No. 5,412,952 describes the addition of buffer volumes connected to the warm ends of the two pulse tubes, with fixed orifices in each connecting line.
[0003] The valve timing described in U.S. Pat. No. 6,256,998 has been found to be more effective than the timing described in U.S. Pat. No. 5,412,952. U.S. Pat. No. 6,256,998 refers to the combination of “four-valve” control, with buffers and fixed orifices, as a “hybrid” pulse tube. It is to be noted that a “fixed” orifice may be adjustable, so that it can be set in a fixed position when the pulse tube is manufactured.
[0004] The four-valve pulse tube is more compact than a double-orifice pulse tube because it does not have buffer volumes; however it is less efficient because all of the phase shifting flow comes from the compressor. Most of the phase shifting flow in the double-orifice pulse tube is exchanged between the buffer volumes and the pulse tubes. A hybrid pulse tube is more efficient than a four-valve pulse tube and can have smaller buffer volumes than a double-orifice pulse tube. The buffer volumes can range in size from almost the zero volume of a four-valve pulse tube to almost the same size as a double-orifice pulse tube would have. Buffer volumes are defined relative to the corresponding pulse tube volumes as a ratio. One of the objects of this invention is to define the volumes for first-stage and second-stage buffers of a two-stage hybrid pulse tube that have been found to provide a good balance between efficiency and size. Another object of this invention is to integrate the buffer volumes into the warm end housing of the pulse tube cold-head assembly.
[0005] Some of the concepts that are incorporated in current pulse tube cold-heads are shown in U.S. Pat. No. 3,620,029. This is an early pneumatically driven GM type expander in which the motion of the displacer is controlled by gas flowing through a fixed orifice between the top of the displacer cylinder and a buffer volume. FIG. 7 of this patent shows a valve motor, in a separate housing, driving a rotary valve, that cycles flow at high pressure from a compressor to a regenerator, then returns it from the regenerator to the compressor at low pressure. The buffer volume is shown in a housing that is separate from the valve motor housing and the valve disc housing. If the displacer were to be removed from the cylinder, the cold-head would become a single orifice pulse tube. In actual practice the buffer volume has been integrated into the valve disc housing as shown in FIG. 1A of U.S. Pat. No. 6,256,997. Many pulse tube patents show the buffer volumes as being separated from the cold head by connecting tubes, e.g. U.S. Pat. No. 5,107,683, U.S. Pat. No. 5,295,355, U.S. Pat. No. 6,256,998, U.S. Pat. No. 6,343,475 and U.S. Pat. No. 6,434,947.
[0006] U.S. Pat. No. 6,378,312 describes a means of integrating one or more buffer volumes, orifices, a valve mechanism, and a valve motor within an integral housing; a housing which has several machined chambers. The pressure oscillation controller, which is usually a rotary valve disk in contact with a valve seat, has to be replaced or repaired when maintenance is needed. This integral configuration has the disadvantage of more difficult maintenance than a cold-head with more direct access to a rotary valve disc.
SUMMARY OF THE INVENTION
[0007] It has been found that the relatively small buffer volumes of the two-stage hybrid pulse tube make it practical to integrate them into the warm housing, with the option of having one in a valve disc housing, and having the valve motor in an attached housing. This combines the benefits of compactness and ease of maintenance. The valve motor assembly can be mounted inline with the pulse tubes or at right angles. The primary near term application is the cooling of MRI magnets that use low temperature superconducting wire, and operate at 4 K.
[0008] However, work is being done on devices that use high temperature superconducting wire and will operate near 30 K. Although present magnets require two-stage pulse tubes, future applications may use single stage pulse tubes. Single stage pulse tubes operate in the same manner as the first stage of a two-stage pulse tube. Thus, the invention disclosed herein may also be applied to a single stage pulse tube.
[0009] This invention defines a range of buffer volume/pulse tube volume ratios for two-stage hybrid GM type pulse tube cold-heads that are designed to produce refrigeration at 4 K. The ranges of volume ratios for the first and second stages provides a good balance between the inefficiencies but compact size of a four-valve phase shifting mechanism and the better efficiency but larger size of a double-orifice phase shifting mechanism. The buffer volumes are small enough to be conveniently machined into the warm end housing, or as an option, one can be part of a valve disc housing. The drive motor for the valve disc is in an attached housing to make the valve disc readily accessible for service.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1 a , 1 b , and 1 c are schematics of double-orifice, four-valve, and hybrid GM type pulse tube refrigerators.
[0011] FIG. 2 is a simplified cross section of a two-stage hybrid GM type pulse tube cold-head which shows a first embodiment of the present invention. It has both buffer volumes and the valve disc in the warm end housing and the valve motor assembly at right angles to the pulse tubes.
[0012] FIG. 3 is a second embodiment of a warm end housing with a first stage buffer, a valve disc housing with a second stage buffer, and an attached valve motor assembly. All of the components are in line with the pulse tubes.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention is applicable to one-stage and two-stage hybrid G-M type pulse tube refrigerators. Like numbers in the figures refer to like parts.
[0014] FIGS. 1 a , 1 b , and 1 c are schematics of double-orifice, four-valve, and hybrid GM type pulse tube refrigerators. Compressor assembly 1 , supplies gas (e.g. helium) at high pressure through line 3 to valve V 1 , 15 , and receives gas from valve V 2 , 16 , through line 2 at low pressure. Valves V 1 and V 2 open and close in sequence to cycle gas in and out of regenerator R 1 , 12 . When valve V 2 is open, gas flow is split at the cold end of R 1 , some flows into the cold end of first-stage pulse tube PT 1 , 10 , and the rest flows into the warm end of regenerator R 2 , 22 . Some of this gas stays in R 2 and some flows out the cold end of R 2 into the cold end of second-stage pulse tube PT 2 , 20 . After valve V 1 closes, valve V 2 opens and the flow is reversed. This process is common to all three types of pulse tubes.
[0015] Phase shifting is accomplished in the double-orifice control mechanism of FIG. 1 a by means of gas cycling through lines that connect from the warm end of regenerator 12 to the warm ends of pulse tubes 10 and 20 through orifices 37 , and 38 , respectively, in combination with gas cycling between the warm ends of pulse tubes 10 and 20 , to buffer volumes B 1 , 14 and B 2 , 24 , through orifices 31 , and 32 , respectively.
[0016] Phase shifting is accomplished in the four-valve control mechanism of FIG. 1 b by means of gas cycling into the warm ends of pulse tubes 10 and 20 , from compressor supply line 3 through valves V 3 , 17 , and V 5 , 27 , and returning to compressor return line 2 through valves V 4 , 18 , and V 6 , 28 , respectively. The rate of flow through valves V 3 , V 4 , V 5 , and V 6 , is set by fixed orifices 33 , 34 , 35 , and 36 , respectively.
[0017] Phase shifting is accomplished in the hybrid control mechanism of FIG. 1 c by means of gas cycling into the warm ends of pulse tubes 10 and 20 from buffer volumes 14 and 24 through orifices 31 and 32 followed by gas from compressor supply line 3 flowing through valves 17 and 27 , then returning to buffer volumes 14 and 24 through orifices 31 and 32 followed by gas returning to compressor return line 2 through valves 18 and 28 , respectively. The rate of flow through valves 17 , 18 , 27 , and 28 , is set by fixed orifices 33 , 34 , 35 , and 36 , respectively. A preferred timing sequence for these valves is shown in FIG. 11 of U.S. Pat. No. 6,256,998.
[0018] It will be understood by one skilled in the art that four-valve control requires all of the phase shifting gas to come from the compressor and that it is the most compact of the three phase shifting mechanisms. It is also understood that double-orifice control is the least compact of the three mechanisms and that both double-orifice and hybrid control require some gas from the compressor.
[0019] While the fraction of the compressor flow that is used to control phase shifting is an important factor in effecting efficiency it is not the only factor. Other factors include the timing of flow and the rate of flow to and from the warm ends of the pulse tubes. Practical factors include the ability to set the size of an orifice during manufacturing, and the long term temperature stability during operation.
[0020] The amount of gas required for phase shifting at the warm end of the pulse tube relative to the amount of gas that flows in and out of the cold end of the pulse tube is dependent on the cold end temperature. For example at 60 K the ratio is about 1 to 4, at 40 K it is about 1 to 6, and at 4 K it is about 1 to 30.
[0021] A two-stage GM type pulse tube cold-head that is designed to cool a superconducting MRI (magnetic resonance imaging) magnet will typically produce refrigeration at 40 K and 4 K. The reduction in flow direct from the compressor by the use of buffer volumes is less important than the other factors discussed above.
[0022] Both double-orifice and hybrid control systems have been studied for two-stage GM type pulse tubes designed to cool MRI magnets. Both systems work. At the present time the hybrid system is favored because of its relatively compact size, good efficiency, and good operating stability. Tests have been run with different size buffer volumes.
[0023] Results of tests for two-stage GM type pulse tube refrigerators designed for MRI cooling are summarized in the TABLE 1. Volumes are expressed as a ratio of the buffer volume to the pulse tube volume.
TABLE 1 Cold Head Type Double-Orifice Hybrid First stage volume ratio, minimum 5.0 0.5 First stage volume ratio, preferred 5.5 2.2 Second stage volume ratio, minimum 3.0 0.2 Second stage volume ratio, preferred 3.5 0.7
[0024] The hybrid type pulse tube is less sensitive to buffer volume size than the double orifice type because more gas flow to the warm end of the pulse tube can come direct from the compressor when the volume is small. TABLE 2 shows the effect on temperature for a hybrid type pulse tube with 40 W and 1 W heat loads on the first and second stages respectively.
TABLE 2 Stage Volume Ratio Temperature - K First stage 0.5 34.4 First stage 2.2 33.7 Second stage 0.2 4.25 Second stage 0.7 4.15
[0025] FIG. 2 is a simplified cross section of a first embodiment of the present invention. Valve motor assembly 4 is attached to warm housing 8 which is attached to the warm flange 9 of two-stage pulse tube assembly 19 . Pulse tube assembly 19 consists of first stage regenerator 12 , first stage pulse tube 10 , first stage warm flow smoother 11 , first stage heat station 13 , second stage regenerator 22 , second stage pulse tube 20 , second stage warm flow smoother 21 , and second stage heat station 23 . Valve motor assembly 4 includes a motor with a drive shaft and drive pin 37 . Gas inlet port 38 is shown as part of valve motor assembly 4 but may be part warm housing 8 . Drive pin 37 turns valve disc 5 which rotates on a valve seat that is shown as part of valve cartridge assembly 6 . Examples of valve port patterns and options for different valve disc and valve seat designs are described in U.S. Ser. No. 60/537,661 and 60/544,144.
[0026] Warm housing 8 is shown as containing first stage buffer volume 14 , second stage buffer volume 24 , valve cartridge assembly 6 , gas passage 41 from ports 15 and 16 , in the valve seat face of 6 , through fixed orifice 33 to first stage regenerator 12 , gas passage 43 from valve port 17 to the warm end of first stage pulse tube 10 through flow smoother 11 , gas passage 44 that returns gas from 10 to valve port 18 through adjustable orifice 34 , and gas passage 42 that connects from 44 through fixed orifice 31 to first stage buffer volume 14 . Valve cartridge assembly 6 also contains valve ports and orifices for the second stage, not shown, that are similar to those shown for the first stage. Gas passages 45 and 46 connect from 6 to second stage pulse tube 20 through flow smoother 21 . Gas returns to the compressor at low pressure through passage and fitting 39 .
[0027] This embodiment of the invention shows valve motor housing 4 attached to the side of warm housing 8 such that the axis of rotation is perpendicular to pulse tubes 10 and 20 . Pulse tubes that operate at 4 K are preferably oriented with the cold end of the pulse down in order to avoid gas convection losses. The right angle orientation of the warm end assembly minimizes the height required above a MRI magnet to remove the pulse tube assembly.
[0028] FIG. 3 shows a second embodiment of this invention in which warm housing 8 is divided into a first part 7 a and a valve housing 7 b for valve disc 5 . The warm end components are shown to be in line with the pulse tubes. The warm end of pulse tube assembly 19 is attached to warm housing 8 by warm flange 9 to which pulse tubes 10 and 20 , not shown, and regenerator 12 are bonded. First stage buffer volume 14 is shown contained in 7 a , the first part of warm housing 8 , and second stage buffer volume 24 is shown contained in valve housing 7 b . Valve cartridge assembly 6 and the gas passages in 8 are the same as shown in FIG. 2 .
[0029] The configurations of the warm end components that are attached to pulse tube assembly 19 , as shown in FIGS. 2 and 3 , are to be taken as representative of other possible configurations in which compact buffer volumes are contained in a single or multi-piece warm housing, that also contains a rotary valve mechanism, and to which a separate drive motor assembly is attached. | A range of buffer volume/pulse tube volume ratios for two-stage hybrid GM type pulse tube cold-heads that are designed to produce refrigeration at 4 K are provided. The ranges of volume ratios for the first and second stages provides a good balance between the inefficiencies but compact size of a four-valve phase shifting mechanism and the better efficiency but larger size of a double-orifice phase shifting mechanism. The buffer volumes are small enough to be conveniently machined into the warm end housing, or as an option, one can be part of a valve disc housing. The drive motor for the valve disc is in an attached housing to make the valve disc readily accessible for service. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 13/248,429, filed Sep. 29, 2011, which application is a continuation of U.S. Pat. No. 8,028,550, issued Oct. 4, 2011, which application is a continuation of U.S. application Ser. No. 11/470,658, filed Sep. 7, 2006, which claims the benefit of Provisional application 60/734,728, filed on Nov. 8, 2005, all of which are incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to laundry appliances and in particular to laundry washing machines for household use.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 6,212,722 proposes an improved laundry washing machine for domestic use. This machine is of the top loading type having an outer bowl, a wash basket within the outer bowl and access to the wash basket through a top opening. A motor is provided to drive rotation of the wash basket within the outer bowl. A wash plate is provided in the lower portion of the wash basket to be rotated by the motor with the wash basket or independently of the wash basket. The patent proposes a combination of water level control, wash plate design, wash basket design and movement pattern for the wash plate which leads to an inverse toroidal movement of the laundry load during a wash phase. The sodden wash load is dragged by friction radially inward on the upper surface of the wash plate and progresses upward in the region of the centre. The sodden wash load then progresses radially outward to the wall of the wash basket and downward to the base of the wash basket. This has been found to provide an effective wash action with low water consumption.
The patent indicates that this is only achieved at water levels within a determinable band. With too much water the inverse toroidal rollover motion is not achieved because the clothes lose frictional contact with the wash plate.
The present inventors have ascertained a desire to include an effective wash mode that sacrifices a degree of water efficiency in favour of dilution of the wash solution. The inventors consider this to be particularly desirable in the case of heavily soiled laundry items or laundry items having insoluble soiling, such as muddy, sandy or grass covered sports clothes, and in the case of laundry subject to dye leakage.
The inventors consider that the laundry machine described in U.S. Pat. No. 6,212,722 is only partially effective in this regard. At higher water levels in which the machine cannot perform the inverse toroidal rollover pattern the inventors consider the machine is likely to provide a less effective wash action. The effect of inverse toroidal wash action by dragging is only available at low water levels, and there is a middle water level at which no rollover occurs. Where the laundry load does not rollover wash action of clothing against the wash plate is limited to a small fraction of the load and wash performance suffers.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a laundry machine which goes some way toward overcoming the above disadvantages or which will at least provide the public with a useful choice.
In a first aspect, the invention may broadly be said to consist in a laundry machine comprising a cabinet, a wash tub supported within the cabinet, a motor suspended beneath the wash tub, a wash basket rotatably supported within the wash tub and drivingly connected to the motor, and a wash plate disposed in the bottom of the wash basket and defining an outer periphery. The wash plate comprises a central hub encircled by the outer periphery, a plurality of vanes extending substantially radially from the central hub toward the outer periphery. The vanes comprise a continuously increasing width as they extend radially away from the hub, a pair of sidewalls diverging as they extend away from the hub, an outer portion terminating at the outer periphery, a shoulder extending from the hub and transitioning into the outer portion, wherein the shoulder is located above the outer portion and both the outer portion and shoulder have a convex cross section. Further, the wash plate is rotatably supported in the wash basket and drivingly connected to the motor to oscillate the wash plate such that the cloth items directly above the wash plate are frictionally dragged in an oscillatory manner and the cloth items rollover within the wash basket along an inverse toroidal rollover path.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cutaway perspective view of a laundry machine according to a preferred embodiment of the present invention.
FIG. 2 is a block diagram of a control system for a laundry washing machine.
FIG. 3 is a perspective view of the wash basket base moulding according to the machine of FIG. 1 .
FIG. 3 b is a perspective view of another embodiment of a wash basket base moulding according to the present invention.
FIG. 4 is a perspective view from above of the wash plate according to a preferred embodiment of the present invention.
FIG. 4 b is a perspective view from above of the wash plate according to present invention as shown in 3 b.
FIG. 5 is a cross-sectional side elevation of the wash plate of FIG. 4 .
FIG. 6 is a plan view of the wash plate of FIG. 4 .
FIG. 7 is a plan view of a section of wash plate including arcuate apertures.
FIG. 8 is a graph of rotational speed versus time, illustrating elements of a wash plate drive profile for exciting toroidal rollover.
DETAILED DESCRIPTION
The present invention relates to improvements and adaptations on the wash system described in U.S. Pat. No. 6,212,722. The contents of that patent are incorporated herein by reference.
A laundry machine incorporating improvements and adaptations of the present application is illustrated in FIG. 1 . The laundry machine includes a cabinet 100 with a lid 102 and a user console 104 . A controller 106 is located within the body of the user console. The controller 106 includes a power supply and a programmed microcontroller. The power supply receives power from the mains supply and supplies power to the microcontroller, to a power supply bridge for the electric motor and to ancillary devices within the machine such as a pump and valves. Delivery of power to the motor 114 and the ancillary devices is at the control of microcontroller. The microcontroller receives inputs from a user interface on console 104 .
A tub 120 is supported within the cabinet. The tub is preferably suspended from the upper edge of the cabinet. The tub may alternatively be supported from below or from the sides of the cabinet. A wash or drain pump is fitted to the lower portion of the tub. The pump is preferably located at a sump portion of the tub.
A wash basket 122 is supported for rotation within the tub. Opening the lid 102 provides user access to an upper open end of the wash basket.
A wash plate 124 is mounted in the lower portion of the wash basket.
The improvements and adaptations of the present invention are preferably implemented in a laundry machine of a direct drive type. However, other drive systems involving for example gearbox or belts may alternatively be used.
A motor 114 below the tub directly drives a shaft 128 . The shaft 128 extends through the lower face of the tub, where it is supported in a pair of bearings 130 . Seals prevent water escaping the tub at the interface between the tub and shaft.
The wash basket 122 is mounted on the shaft within the tub. The wash basket may typically comprise a base 132 and a perforated cylindrical skin 134 . The perforated cylindrical skin extends up from the base to define an open ended drum. The wash basket may include a balance ring at the upper edge of the cylindrical skin.
The wash plate 124 is also fitted to the shaft, within the wash basket 122 .
An arrangement is provided to enable the motor 114 to selectively drive either the wash plate 124 independently of the wash basket 122 , or drive the wash basket 122 . In driving the wash basket the motor may also drive the wash plate. Various mechanisms have been proposed to accomplish this selective drive. A number of variations including twin concentric shafts and a selectable clutch to connect the motor with either or both shafts are noted in the prior art and may be applied.
Alternatively a floating clutch of a type previously described in U.S. Pat. No. 5,353,613 may be used. The machine illustrated in FIG. 1 makes use of such a floating clutch. The wash basket 122 is slidably mounted on the drive shaft 128 . The wash plate 124 is fixed to rotate with the upper end of the drive shaft. The wash basket 122 includes float chambers 140 on the underside of the wash basket base member. The wash basket is allowed to rotate on the shaft. A vertically inter-engaging clutch 142 is provided between the wash basket 122 and wash plate 144 or between the wash basket 122 and shaft 128 . A first clutch member having upwardly facing engagements may be provided in conjunction with the wash plate or a spline on the shaft. A downwardly facing clutch member is provided in conjunction with the wash basket. With the wash basket in an upper or raised position the upwardly facing and downwardly facing clutch members are not engaged and the wash basket is free to rotate on the shaft. With the wash basket in a lower position the members are not engaged. In use the wash basket will be disengaged from the shaft when sufficient water has been added to the tub for the wash basket to float to its raised position. The amount of water required before the wash basket floats depends on the weight of laundry in the wash basket. In the floated condition the shaft will drive the wash plate but will not directly drive the wash basket. In the lower condition the shaft will drive the wash plate and wash basket together.
The controller is part of a control system for coordinating the operations of the laundry machine. The control system is illustrated in the block diagram of FIG. 2 . The controller includes a microcontroller 800 . The microcontroller may include a micro computer and ancillary logic circuits and interfaces. The micro controller receives user input commands on user interface 802 . The user interface may include, for example, a plurality of touch controls such as switches or buttons, or may include a touch screen, or may include rotary or linear selection devices. The micro controller may include a display device 804 to provide feedback to a user. The display device may comprise a plurality of indicators, such as lights or LEDs, or may include a screen display. The display device 804 and the user interface 802 may be mounted to a single module incorporating the micro controller.
The micro controller receives power from a power supply 806 . The micro controller also controls power switches 808 applying power from supply 806 to drive motor 810 . The micro controller controls further power switches 812 applying power from supply 806 to a pump 814 . The micro controller also controls a power switch 830 applying power to a cold water inlet valve 832 and a power switch 834 applying power to hot water inlet valve 836 .
The micro controller preferably receives feedback from position sensors 816 associated with the motor. These sensors may for example be a set of digital Hall sensors, sensing changes in rotor position, or may be any suitable encoder. Alternatively rotor position and movement may be sensed from motor drive current or EMF induced in unenergised motor windings.
The micro controller also preferably receives input from a water level sensor 818 , which detects the level of water in the tub of the machine, and from a temperature sensor 820 which detects the temperature of water being supplied to the wash tub.
The present application presents several adaptations that enhance the operation of a wash system attempting to induce inverse toroidal rollover by frictional dragging or by fluid mechanics. These adaptations enhance the ability to generate inverse toroidal rollover wash pattern at low water levels and help extend the water levels at which this wash pattern can be maintained. A number of these adaptations involve the shape and configuration of elements of the wash plate. In particular they involve the form of the upper surface of the wash plate, including the presence and location of apertures through the wash plate. Other adaptations involve the shape and size of buffers arrayed on the base of the spin tub around the periphery of the wash plate. An additional aspect involves control methods for helping establish and maintain the inverse toroidal rollover pattern and for beneficially extending the range of operation of the inverse toroidal rollover to higher water levels.
Exemplary wash plates are illustrated in FIGS. 4 to 6 . FIGS. 3-5 illustrate one exemplary wash plate and FIGS. 3B and 4B illustrate a second exemplary wash plate. As shown in FIGS. 4 and 4B , the wash plate rises from a generally circular periphery 400 to a raised central hub 402 . The upper surface of the wash plate is broadly divided into alternating sectors. The alternating sectors comprise raised sectors 404 , or vanes, and intermediate lower sectors 406 . The lower sectors 406 are in the general form of a shallow cone with increasing gradient toward the hub 402 , so as to be outwardly concave in radial cross-section. This can generally be seen in FIG. 5 . In the outer region of the wash plate the low sectors 406 have a generally shallow gradient. In the region closest to the hub 402 the low sectors 406 of the wash plate have a higher gradient.
Each vane 404 has a form devised to enhance initiation and maintenance of inverse toroidal rollover by encouraging the inward dragging of laundry items by friction that are in contact with the upper surface of the wash plate. This enhanced form includes three major features. It is believed that each of these features independently offers an improvement over prior forms. The cumulative improvement offered by these features enables the appliance to maintain inverse toroidal rollover at higher water levels.
Each vane includes a divergent form wherein the width of the vane increases moving from the hub to the periphery of the wash plate. Further, each vane includes steep side walls 410 adjacent the neighbouring low sectors of the wash plate.
The upper face of an outer portion 412 of each vane is generally flat and the vane slopes down towards its outer periphery 414 to the level of the circular periphery 400 of the wash plate.
Each steep side surface 410 of each vane is outwardly concave. That is, the side surfaces of each vane diverge more rapidly as the vane extends toward the outer periphery 400 of the wash plate. Furthermore the opposing side surfaces 410 of adjacent vanes, facing toward one another across the low sector 406 between them, are each concave relative to the other and relative to a radius extending from the centre of the wash plate. The outermost portion of each sidewall hooks toward the adjacent vane so as to be inclined in advance of a radial plane of the wash plate. The inventors have found that such side surfaces 410 aid in dragging the cloth items inward to the centre of the wash plate.
Rapid oscillation of the wash plate provides a centrifugal pumping action inducing radially outward water flow. Such radial flow above the wash plate may inhibit inward movement of the laundry items and is detrimental to establishing the inverse toroidal rollover pattern. The shape of the side surfaces 410 also counteract the centrifugal pumping action of the wash plate as it is oscillated. The inventors have found that the side surfaces 410 aid in achieving inverse toroidal roll-over at all water levels.
In the region of the vane 404 nearer the hub 402 a ridge or shoulder 420 rises from the general outer portion 412 of each vane. The ridge or shoulder 420 has side faces 422 rising to a ridge. The side faces of the shoulder 420 are less steep than the steep side faces 410 . When the wash plate is oscillated the angled side faces 422 of the shoulder 420 push on the laundry items near the hub 402 so as to impart a vertical component of force on them. Laundry items near the centre of the wash plate are then thrust upward, which aids inverse toroidal motion.
Preferably there are a plurality of such vanes 404 , for example 3, 4, 5 or 6 such vanes. Most preferably there are 3 or 4 such vanes.
Preferably the relative proportion of vane to plan area of the wash plate, is between 0.33 and 0.66.
The shape and size of the washplate, including shoulder area, along with basket capacity, and drive profiles used by the controller, can impact motor temperatures. Accordingly these factors need to be balanced according to the overall machine requirements.
The inventors have found that by providing apertures 430 through the wash plate, radial outward water flow is induced below the wash plate by the shape of the underside of the vanes 404 , and that this reduces or compensates for induced outward flow above the wash plate. To enhance outward flow under the wash plate the underside of the wash plate may include a plurality of spaced radial ribs 432 .
The base of the wash basket preferably includes an annular series of flow channels extending from the upper side of the base through to the lower side of the base. These channels 304 can be seen in FIG. 3 . Fluid may flow from apertures 430 and through these flow channels to the region below the wash basket, between the wash basket and outer tub. This fluid may flow from there out to the wall of the outer tub, upward between the wall of the outer tub and the cylindrical wall of the wash basket and then inward through the perforations of the wash basket. The water flow carries lint into the space between the wash basket and the tub. This lint becomes caught up on the outside of the spin basket and tends not to reenter the spin basket. The lint is then removed in the drain operation subsequent to the wash cycle or is extracted by a lint filter in a recirculation system.
Furthermore, the apertures 430 through the wash plate are preferably provided adjacent each steep side wall 410 of each vane as shown is FIG. 4 , or between each steep side wall 410 as shown in FIG. 4B . It is believed that the suction effect generated by the pumping action under the wash plate draws laundry items against the upper surface of the wash plate in these regions directly adjacent the side walls 410 of the vanes. This enhances contact of the laundry items with the side walls 410 . It is believed that this contact promotes the inverse toroidal rollover wash pattern. The inventors consider that this effect is useful in promoting maintenance of the inverse toroidal rollover wash pattern with higher water levels, where laundry items otherwise tend to float out of contact with the wash plate.
The apertures 430 may comprise small groupings or arrays of circular or shaped holes adjacent the side walls of the vane, or alternatively may comprise one or more elongate slots through the wash plate in the region adjacent the vane. FIG. 7 illustrates an example wash plate including arrays of short curved slots 700 , or arcuate holes, in place of circular holes. Sufficient apertures may be provided in the regions of the low sectors adjacent the sidewalls, and may therefore be excluded from regions of the low sectors that are not close to the sidewalls of the vane.
To enhance the dragging effect of the laundry over the surface of the oscillating wash plate the inventors consider it advantageous for the spin basket to resist movement relative to laundry in the lower portion of the spin basket. For this purpose a series of tall buffers was proposed in U.S. Pat. No. 6,212,722. The present inventors now believe that smaller buffers that do not interact with laundry that is well above the level of the wash plate are preferable. A spin basket base member 300 including an annular series of buffers 302 of preferred form is illustrated in FIGS. 3 and 3B . The base member includes a hub portion 308 and a periphery 306 . With the wash plate in place the periphery 306 of the base member 300 encloses the space between the outer edge of the wash plate and the cylindrical wall of the wash basket. As seen in FIG. 3 the preferred buffers have a very low profile. Each buffer extends radially inward from the side wall of the spin basket. Each buffer preferably has a height of less than 3 cm, relative to the surrounding surface of the base member. Each buffer has a flattened shape, being several times wider that its height. Each buffer tapers as it extends in toward the wash plate.
The washer is capable of washing in two modes, a high efficiency mode and a traditional deep fill mode. In high efficiency mode the water to clothes ratio is typically less than 10 liters/kg. The traditional deep fill wash typically uses over 15 liters/kg. The two modes each have their benefits. The high efficiency mode uses less water and the more concentrated detergent solution gives excellent soil removal results for soluble soils. The traditional mode uses more water but is better at removing insoluble soils, such as sand and grass.
Wash performance in both modes requires achieving sufficient turnover of the clothes. In the high efficiency mode, higher contact with the wash plate due to lower water level means a marriage between plate shape and plate movement can readily create the inverse toroidal motion.
The preferred controller applies an initial wash plate drive profile to initiate the inverse toroidal motion. The initial drive profile is characterised by higher angular velocity and longer stroke length to start the clothes movement. This movement is subsequently maintained by a maintenance drive profile with lower angular velocity and stroke length. Many drive systems are possible for controlling wash plate drive profiles. One example is described in U.S. Pat. No. 5,398,298.
The initial drive profile is varied according to load size. The profile is more vigorous for larger load sizes. The load size is determined from the amount of water required to float the wash basket. The controller chooses the profile from the bowl float level.
Preferably the maintenance drive profile is also varied according to load size. Again the profile is more vigorous for larger load sizes.
By way of example in the preferred embodiment of the present invention the preferred controller can adaptively adjust the drive profile from stroke to stroke to try and maintain a drive profile of certain measured characteristics. An example drive profile is illustrated in FIG. 8 . The idealised profile is represented by the solid line. The profile achieved using the control methods described in U.S. Pat. No. 5,398,298 is illustrated by the dot-dash line. The profile includes a ramp where the wash plate speed increases approximately linearly. This ramp is followed by a plateau period. After the plateau period, the wash plate and motor coast to a stop. The stroke is then repeated in the reverse direction. The measured characteristics are plateau speed (ω), ramp time and plateau time. A more vigorous profile is characterised by greater energy input. In the measured characteristics this may be indicated by higher target plateau speed and reduced target ramp time while maintaining an overall stroke duration or angular stroke length.
For example in a test machine the inventors have found the following values for the measured characteristics to provide acceptable results:
SMALL LOADS
Initial Profile
Maintenance Profile
Load
Ramp
Plateau
Ramp
Plateau
Size
Speed
Time
Time
Speed
Time
Time
1 kg
85
332
500
77
321
400
2 kg
89
299
500
80
299
400
3 kg
95
255
500
86
270
400
MEDIUM LOADS
Initial Profile
Maintenance Profile
Load
Ramp
Plateau
Ramp
Plateau
Size
Speed
Time
Time
Speed
Time
Time
3
kg
91
270
375
87
294
275
3.7
kg
96
255
400
91
284
300
5.0
kg
105
248
412
99
277
325
LARGE LOADS
Initial Profile
Maintenance Profile
Load
Ramp
Plateau
Ramp
Plateau
Size
Speed
Time
Time
Speed
Time
Time
5.5 kg
120
228
462
108
262
362
6.5 kg
128
216
488
113
257
375
7.0 kg
130
208
500
116
252
387
The preferred controller operates an adaptive control where the rate of increase in an applied motor voltage, a point of cutting off this rate of increase, and a period of subsequent steady voltage, are each varied from stroke to stroke based on feedback of the resulting measured characteristics of previous strokes. These adjustments may be made in accordance with the methods set out in U.S. Pat. No. 5,398,298.
Acceptable wash performance is considered a compromise between achieving regular inverse toroidal turnover of a wash load within the spin basket and wear and tear associated with wash profiles that are too vigorous (and speeds that are too high) or entanglement (angular strokes that are too long).
In the preferred implementation each of the target measured characteristics for the initial profile is set according to the size of the wash load. The target measured characteristics are also set for the maintenance profile according to the load size. The size of the wash load may be measured in a number of ways known to persons skilled in the art. In the implementation preferred by the inventors the size of the wash load is determined from the level of water in the tub, measured by a water level sensor of any known type, at the water level when the spin basket floats and becomes disconnected from the motor drive shaft. This disconnection may be ascertained by monitoring changes in motor performance which indicate that the motor is no longer directly driving rotation of the spin basket.
The inventors have ascertained that these target characteristics of their preferred initial drive profiles and maintenance drive profiles can each be modelled as a curve or series of curves. Accordingly, preferred values for use by the microcontroller may be read from lookup tables or derived from appropriate formulae.
In the traditional deep fill mode there is less contact with the plate. The inverse toroidal laundry movement is started at a low water level preferably the same level as the high efficiency mode using the initial drive profile. However, rather than backing off into the maintenance profile once the inverse toroidal motion is established, for the traditional wash, the controller continues the vigorous profile while continuing to add water.
To initiate inverse toroidal motion the initial drive profile is preferably applied for from one to three minutes. The maintenance profile is generally sufficient to maintain the inverse toroidal motion once the motion has been established. This reduced vigour profile is more suitable for general wash action on the laundry load without excessive wear.
However the inverse toroidal motion may be lost, for example due to unusual load distribution or entanglement of laundry items. Accordingly, in the preferred embodiment of the invention the initial, or a similar vigorous profile, is applied for short periods intermittently in the wash cycle.
The preferred laundry washing machine implementing the present invention includes the capacity to circulate wash liquor from the lower portion of the wash tub to pour or spray the wash liquor onto the laundry load from a location above the laundry load. For example a conduit may lead from the lower portion of the tub to a spray nozzle overhanging the wash basket at the upper edge of the tub. A lower end of the conduit may be supplied with wash liquor from the lower portion of the tub by a pump. The pump may be a separate recirculating pump, or may be the drain pump, with a diverter valve selectively supplying wash liquor to a drain hose, or to the recirculation conduit.
In the case of this preferred laundry device it is preferred that the inverse toroidal rollover wash pattern is established after an initial period of circulating wash liquor without agitation.
This period may include the period prior to there being sufficient wash liquid to establish inverse toroidal rollover. For example, in the most preferred machine including floating disconnection between the spin basket and drive shaft, circulation can occur in the period before disconnection. The period of circulation without agitation may go on beyond this initial float period.
According to a further aspect of the present invention, in a preferred machine with recirculation of wash liquor, the recriculation may be activated during the inverse toroidal rollover wash pattern. The recirculation may be active during establishment of rollover or during maintenance of rollover. In some circumstances the inventors prefer to intermittently activate recirculation during maintenance of toroidal rollover. They consider that this draws water from generally below the wash load and applies this wash liquor to generally above the wash load. This encourages contact between the laundry items and the wash plate. This may be particularly effective in conjunction with the apertures through the wash plate, as this circulation liquid is drawn from wash liquid beneath the spin basket, and this liquid has generally passed through the apertures of the wash plate. The inventors further consider that this may be particularly beneficial in the case of increased water levels, where transfer of wash liquid from below to above the laundry will discourage or counteract floating.
The curving steep side walls and raised shoulders of the wash plate vanes create enough inward and then upward movement to keep the inverse toroidal motion going even when there is reduced contact between the clothes and the wash plate.
In summary, wash plate and drive profile design have created a wash system that means both high efficiency and traditional washing modes are possible in the one machine. | A laundry machine configured to supply a first amount of water to the wash tub wherein a wash plate can be oscillated such that clothes items directly above and in contact with the impeller are frictionally dragged in a oscillatory manner with the wash chamber while continuing to oscillate said wash plate, an additional supply of water is added to said wash tub such that as cloth items lost frictional engagement with the wash plate, the cloth items continue to move along an inverse toroidal rollover path at higher water levels. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to systems for monitoring processes where an intense point source of light is generated incident to a metal working process, and is specifically concerned with a video monitoring system and method for monitoring a gas and arc welding or cutting operation.
Systems for video monitoring an arc welding operation are known in the prior art. Such systems are often used in situations where it is impossible or impractical for a human operator to have direct, hands-on access to the workpiece such as when a weld must be produced in the inner diameter of a pipe, or within the radioactive environment of a nuclear steam generator. These video monitoring systems allow the welder to observe the position of the electrode and the filler wire relative to the workpiece, as well as the characteristics of the weld puddle created by the electric arc. This information helps the operator to remotely control the dynamics of the weld puddle so that the weld is produced uniformly and without flaws.
Unfortunately, the images produced by such video monitoring systems are generally not as clear and informative to a welder as the image he might see through a conventional welding hood. This difference in quality stems largely from the fact that the sensing circuit of a conventional television camera (which is a pixel array of a light-sensitive charge coupled device) does not have the interpretative abilities that the human eye does when used in combination with the brain. While the filter glass used in a conventional welding hood produces an image wherein the arc is essentially white and the background of the workpiece is very nearly black, the eye and brain are able to interpret this image so that the welder is able to see fairly clearly the position of the electrode of the torch relative to the workpiece, the resulting weld puddle, the contour of the weld, and the wettability of the leading edge of the puddle. However, in the case of a television camera, the bright image of the arc saturates a portion of the charge coupled device (CCD) of the light sensing circuit, yielding a television image that includes severe contrasts wherein the background surrounding the electric arc is darkened into obscurity. Additionally, the applicant has noted that some of the light filtration components in these systems are apt to create "ghost" images and stray refractions which further blur the resulting image. In an attempt to balance these severe contrasts, some prior art television systems have employed pulsed light sources such as xenon flash units or lasers synchronized with the actuation of the television camera, in combination with narrow bandwith filters which conduct only a very narrow range of light frequencies that are present in the spectrum of the arc light. Unfortunately, the use of such background lighting necessitates the positioning of still another component in the often limited access area around the weld, and significantly increases the cost of the operation of the monitoring system. Additionally, systems that use such narrow bandwidth filters are only capable of generating a black and white image, which gives the system operator less information than a color image, particularly when the system is used to inspect a completed weld.
In addition to the problem of obscuring contrasts, a second major problem associated with many prior art systems is the mechanical interference that the components of the video monitoring system impose upon the movement of the weld head. In some systems, the movement of the weld head is limited by a relatively large and bulky camera assembly which is connected directly on the weld head. The relatively large and bulky size of such camera assembly is due in part to the fact that such assemblies must contain not only the television camera, but a separate array of lenses, electronic light valves, iris diaphragms, neutral density filters or cross-polarizing filters all positioned in tandem which are used to dim the image of the arc before it strikes the light-sensitive array of charge coupled devices within the camera. In an attempt to solve the mechanical interference problems caused by the mounting of the camera assembly on the weld head, some other prior art systems use fiber optical cables to remotely transmit an optical image to a television camera. However, these fiber optical cables lose a great deal of the transmitted light which reduces the resulting resolution of the television image, and are easily browned and burned out by radiation which in turn necessitates frequent replacement.
Clearly, there is a need for a television monitoring system for observing a welding operation which produces a clear, sharp and contrast-balanced image where the portion of the workpiece surrounding the welding arc is easily visible without the need for auxiliary background lighting. Ideally, such a system should be compact enough in design so as to offer little or no mechanical interference to the weld head as it is manipulated during a welding operation. Moreover, the system should be comprised of a small number of simple and inexpensive parts that are capable of producing a clear and well lighted welding images under a variety of different conditions and for a variety of different welding systems. Finally, the system should be sensitive to a variety of different light frequencies so that the generation of a color image is possible, be easily installable onto a variety of existing tungsten-inert gas weld heads, and be completely safe to use under all conditions.
SUMMARY OF THE INVENTION
Generally speaking, the invention is an system for visually monitoring a process that involves the generation of an intense point source of light adjacent to a workpiece, such as an electric arc used to weld a piece of metal, that overcomes the disadvantages of the prior art. The system of the invention comprises a lens assembly for projecting an image of the point source of light and the area of the workpiece being worked onto an image sensing circuit, which is preferably the CCD pixel array of a television camera whose output is displayed on a television monitor, a filter assembly having at least one filter element that includes a central region of low light transmission for dimming the image of the point source of light that the lens assembly projects onto the sensing means and a peripheral region of high light transmission for freely transmitting the image of the area where the workpiece is being worked, and a means for adjusting the apparent size of the central region of low light transmission relative to the image. In the preferred embodiment, the adjustment means may be with a mechanical or an electronic iris disposed in front of or within the lens assembly. In the alternative, the adjustment means may be a telescopic mounting that allows the filter assembly to be moved either toward or away from the CCD array of the television camera. In either case, the filter assembly is preferably located within the television camera along the optical axis of the lens assembly at a point outside of the image and objective focal plane so that the resulting image of the region of low light transmission appears softened around its edges, thereby avoiding potentially harsh and distracting filter transitions in the resulting video image.
Each of the filter elements of the filter assembly may be formed from a section of developed photographic film whose central region includes a circle of photographic emulsion and whose peripheral region is formed from clear film free of any photographic emulsion. For this purpose, the applicant has found that KODAK Tri-X Pan film works unusually well due to the high light transmissivity of a developed portion of this film that is free from photographic emulsion. In the preferred embodiment of the filter assembly, three filter elements are stacked together such that their circularly shaped central regions of low light transmission concentrically overlap one another. As at least some of these regions are of different diameters, the aggregate central region of the filter assembly yields a pattern of concentric rings which become progressively darker closer to the center of the region. In the preferred embodiment, the filter assembly, lens assembly and iris are all contained within the body of a commercially available miniature television camera.
The system further comprises a means for uniformly attenuating the brightness of the image projected onto the charged coupled device array, which is preferably in the form of a high speed electronic shutter that is included within the image processing circuitry connected between the television camera and the television monitor. When this shutter is operated at a speed of 1/1000 of a second, approximately 94 percent of the light forming each part of the aggregate image is attenuated. In the alternative, neutral density filters, electronic light valves, or an additional iris diaphragm may be used to attenuate the light of the image, either singly or in combination. However, the use of an electronic shutter for this purpose provides the most compact camera and housing arrangement as it obviates the need for the addition of other optical components to the lens assembly.
The housing of the system is a water cooled housing that contains and protects the television camera, which in turn contains the lens assembly, the filter assembly, the light-sensitive CCD array and the iris used for adjusting the apparent size of the central region of the filter assembly. This housing is preferably water cooled, and is advantageously connected to the water cooling circuit that is normally present in a standard arc welding and cutting torch to cool the torch block thereof during a welding operation. Finally, the system includes a current pulsing circuit for use in connection with the electrical power supply that is connected to the torch electrode so that the brightness of the electric arc may be cyclically minimized, as well as a gating circuit for conducting the video signal from the television camera to the television monitor only when the arc brightness is at a minimum.
In operation, the water-cooled housing containing the television camera is oriented relative to the torch assembly by means of an adjustable bracket so that the aggregate central region of the filter assembly is superimposed over the image of the electric arc. The operator of the system then adjusts the relative size of the central region of low light transmissivity so that it just covers the bright electric arc. The ability of the system to precisely control the size of the central region of low light transmission in the television image allows the weld puddle and the surrounding area of the workpiece to be clearly seen without heavy, uniform light filtration and hence without the severe contrasts produced by prior art welding monitoring systems. To further enhance the quality of the resulting image, the power to the weld head may be cyclically pulsed by the current pulsing circuit so that the brightness of the resulting arc periodically falls to a minimum value, and the gating circuit may be adjusted to conduct the video signal from the camera to the television monitor only during these periods of minimum arc brightness.
BRIEF DESCRIPTION OF THE SEVERAL FIGURES
FIG. 1 is a schematic diagram of the video monitoring system of the invention as applied to a conventional arc welding system;
FIG. 2 is a side view of the television camera assemblies of the video monitoring system mounted onto a gas tungsten arc welding torch and wire manipulator;
FIG. 3 is a cross-sectional plan view of one of the camera assemblies illustrated in FIG. 2 along the line 3--3;
FIG. 4 is a cross-sectional side view of the camera disposed within the camera assembly illustrated in FIG. 3;
FIG. 5 is an exploded view of the filter elements of the filter assembly within the television camera of the system, illustrating how the centralized areas of low light transmission are each concentrically arranged with respect to the optical axis of the television camera;
FIG. 6 illustrates how the aggregate central area of low light transmission of the filter elements is superimposed over the image of the bright arc emitted by the weld electrode in order to balance the amounts of light received from the arc and the portion of the workpiece surrounding the arc;
FIGS. 7 and 8 are graphs illustrating how the transmissivity of the aggregate centralized region of the stack of filter elements decreases toward the center, and how the transition zones between the concentric areas of low light transmissivity may be softened by positioning the filter assembly out of the focal planes of the lens assembly of the television camera; and
FIG. 9 is a graph illustrating how the amount of current delivered to the electrode of the torch may be cyclically lowered to a relatively low amperage, and how the gating circuit of the system may be adjusted to conduct the video signal only during the troughs in the square wave current output curve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The system 1 for video monitoring a welding operation on a workpiece 2 which may be a pair of pipe sections 3a,3b being welded together generally comprises a television monitoring system 4, a pair of television camera assemblies 5a,5b mounted on either side of the workpiece 3, an image processing circuit 7 which may be any one of the number of conventional video processing circuits, and television monitors 8a,8b for displaying the images received by the camera assemblies 5a,5b. In the preferred embodiment, both of the cameras within the camera assemblies 5a and 5b and the image processing circuit 7 are all parts of a Model No. EM-102 video monitoring system manufactured by Elmo, Incorporated located in New Hyde Park, N.Y. In the alternative, a Toshiba Model No. M-10B video monitoring system may be used. The system 1 also includes a gating circuit 9 for cyclically interrupting the transmission of the video signal from the image processing circuit 7 to the video monitors 8a,8b, the frequency of the cycle of interruption being adjustable. Finally, a current pulser 11 is included within the system 1 for cyclically varying the current conducted to the weld head used in conjunction with the system 1. In the preferred embodiment, current pulser 11 in a "Pulse Plus" model current pulser manufactured by M-K Products located in Irvine, Calif. Such a pulser is capable of cyclically varying the current conducted to a weld head in a square-wave pattern anywhere between 5 and 400 amps at a periodic frequency of anywhere between 40 and 600 cycles per second. As will be discussed in more detail hereinafter, the operational frequencies of the gating circuit 9 and the current pulser 11 may be coordinated so that the television monitors 8a and 8b display an image only when the current supplied to the torch electrode is at a minimum and the electric arc is at its dimmest.
The welding system 12 that the video monitoring system 1 is preferably used in conjunction with includes a torch assembly and wire manipulator 13 having a tungsten electrode 14 that is surrounded by a gas-conducting ceramic sleeve 15. The tungsten electrode 14 of the torch assembly 13 is electrically connected to a power supply 16, and mechanically connected to a robotic arm 17 that remotely guides and manipulates the weld head 13. The torch assembly 13 is further connected to a bottle of pressurized, inert gas 18 such as argon through the power supply 16. Specifically, the power supply 16 includes a fitting 20 for receiving an inlet hose 22 connected to the bottle 18 of pressurized gas, as well as an outlet hose 24 that is in turn connected to a fitting 26 centrally located within the torch assembly 13. The power supply 16 is connected to the current pulser 11 by way of a power cable 28, and the pulser 11 is in turn connected to the torch assembly 13 by means of another power cable 30 by way of an electrical and mechanical connector 32. The power supply 16 has water circulation inlet and outlet hoses 35a and 35b. These hoses are respectively connected to the inlet and outlet hoses 37a,37b of the torch assembly 13, as well as the inlet and outlet hoses 39a,39b, and 41a,41b connected to both of the camera assemblies 5a and 5b in order to maintain the camera assemblies and the torch assembly 13 cool during a welding operation. In the preferred embodiment, the power supply 16 is a Gold Track II type power supply manufactured by Dimetrics located in Diamond Springs, Calif. Of course, any one of a number of other conventional welding power supply 16 may be used in conjunction with the system 1 of the invention. A wire feeder 42 is further included with the torch assembly 13 in order to provide a uniform supply of fusible metal during a welding operation which may be used to fill the weld joint or to build up weld overlays.
With reference now to FIGS. 1 and 2, coaxial cables 43 and 45 connect each of the camera assemblies 5a and 5b to the image processing circuitry 7 of the video monitoring system 4. The image processing circuit 7 of the Elmo video system electronically shutters the image it receives from the CCDs of the camera assemblies 5a,5b, and circuit 7 has an electronic shutter control 47 for selecting the speed of this electronic shutter. In the Elmo Model No. 102 camera system, the electronic shutter control 47 allows the operator to choose between a shutter speed of 1/60th of a second, or 1/1000th of a second. During a welding or cutting operation, a shutter speed of 1/1000th of a second is preferred since such a shutter speed results in a 95 percent uniform attenuation of the intensity of the video image signal generated by the CCD array within the camera assemblies 5a and 5b. Hence, the practical effect of such a relatively fast shutter speed is that of a neutral density filter which uniformly blocks approximately 95 percent of the light striking the CCD array within the television assemblies 5a and 5b without any of the stray light refractions or detail-diminishing side effects that optical filters can impose upon the camera optical system. The image processing circuitry 7 also includes a gain control 50 which the operator may use to adjust the overall brightness of the image displayed on the television monitors 8a and 8b. Turning now to the current pulser 11, this device has controls 51a and 51b for adjusting both the maximum and minimum amperages of the current entering the torch assembly 13, as well as the frequency of the current fluctuations. In the preferred mode of operation, the frequency control 51b is set so that the current pulses from a relatively high amperage to a relatively low amperage once every 160th of a second. Finally, motor power cables 52a and 52b extend out of the back portions of each of the camera assemblies 5a and 5b as shown. Each of these motor cables 52a and 52b are ultimately connected to the output cable 53 of a motor power source 54 which generates either a positive or a negative DC current having a voltage of anywhere between 1 and 12 volts. As will be seen presently, the motor power cables 52a,52b are connected to iris drive motors which selectively open or close a mechanical iris disposed within each of the camera assemblies 5a,5b.
With reference now to FIGS. 2 and 3, each of the television camera assemblies 5a and 5b is provided with a housing 55 preferably formed from aluminum or some other heat conductive material. The housing 55 of each camera assembly 5a,5b contains a television camera 57 having a cylindrical body 58 that is formed in two parts which are threadedly interconnected by means of a body coupler and extender 59. In instances where the television camera 57 is used to directly view a welding operation, the body coupler and extender 59 will merely serve to couple the cylinderical body 58 together as is shown in FIG. 3. However, in instances where the television camera is used to view a welding operation indirectly through a bundle of optical fibers, the body coupler and extender 59 will be made approximately 1/2 inches long so as to lengthen the cylindrical body 58 of the television camera 57 by that distance in order to expand the image received by the fiber optic bundle to fill up the field of view of the camera. Further contained within the housing 55 is an iris drive motor 60 that is connected to the previously mentioned 12 volt motor power source 54 by means of motor power cables 52a and 52b. In the preferred embodiment, the iris drive motor is a Model 10-16 reversible DC motor manufactured by MicroMo located in St. Petersburg, Fla., having a gear train reducer that converts 256 input turns to one output turn.
The housing 55 of each of the camera assemblies 5a and 5b is connected to a flange 61 that overhangs both sides of the torch assembly 13 by means of a bracket 63. Each bracket 63 is provided with a pivoting joint 65 that allows the front face of the housing 55 to be oriented so that it faces the tungsten electrode 14 of the torch assembly 13. The bracket 63 further includes a leg 67 connected to the pivoting joint 65 that extends through a bore 69 in one end of the flange 61. Leg 67 is rotatably movable within the bore 69 so as to impart panning movement to the camera assemblies 5a and 5b. Additionally, the leg 67 may be extended or retracted through the bore 69, therefore imparting some degree of height adjustment to the camera assemblies 5a and 5b. A set screw 71 allows the leg 67 to be secured into a desired orientation with respect to the bore 69.
At the front end of the housing 55, a pair of miniature, high intensity lamps 72 are mounted for providing a flood-type illumination of the area of the workpiece being welded in the preferred embodiment. Each of the high intensity lamps 72 is a Model L-1021 type incandescence bulb available from the Bulles-Gillway Corporation located in Wobourn, Mass. Such bulbs require a DC current of 3.5 volts, and are capable of generating 1200 luxs. The front end of the housing 55 also includes a circular opening 73 for admitting light from the area of the workpiece being welded to the television camera 57. A protective window 74 is mounted just inside the circular opening 73 by means of retaining clips 75. This window 74 is preferably formed from heat resistant, Pyrex glass, and serves to protect the objective lens of the lens assembly of the television camera 57 from the heat, fumes, and splattering metal created by the welding operation. A fiber optical connector 75.5 (indicated in phantom) may optionally be mounted over the front end of the housing 55. This connector 75.5 is generally tubular in shape, and terminates in a flange which may be conveniently secured onto the front face of the housing 55 by mounting screws. When the camera 57 is used in conjunction with a fiber-optic bundle, the protective window 74 is removed and the end of the fiber-optic bundle (not shown) is placed so that it is approximately 1/16th inch (1.5875 millimeters) from the front surface of the objective lens of the camera 57. Additionally, the short body coupler and extender 59 shown in FIG. 3 is replaced with one which is longer with respect to the longitudinal axis of the camera 57 so that the lens assembly of the camera 57 is positioned approximately 1/2 inch further away from the CCD. Such longitudinal displacement of the lens assembly from the CCD allows the image projected by the fiber optic bundle to completely fill the field of view of the CCD. At their back ends, each of the housings 55 of the camera assemblies 5a and 5b includes a pair of pipette nipples 76a, 76b; 77a and 77b, respectively. These nipples each communicate with a bore 79 that circumscribes the housing 55. In operation, water is circulated through the bore 79 from the nipples 76a, 76b, 77a and 77b in each of the cameras 5a and 5b. Finally, the housing 55 of each of the camera assemblies 5a and 5b includes a cable connector 81 for connecting the output of the CCD pixel array of each of the cameras 57 to the image processing circuitry 7.
Turning now to the interior of the housing 55, the iris drive motor 60 includes an output shaft (not shown) which is in turn linked to a gear train 60.1 as shown which reduces the rotary output of the motor 60 by a ratio of 256 to 1. This gear train 60.1 terminates in a drive shaft 83 which is in turn connected to a drive wheel 85. Drive wheel 85 is turn linked to a rotatable iris control 87 which serves to open or close a mechanical iris 88 disposed within the lens assembly 92 of the camera 57. Linkage is achieved between the drive wheel 85 and the rotatable iris control 85 by means of a flexible belt 90. The belt 90 engages the drive wheel 85 and the rotatable iris control 87 tightly enough to effectively transfer a rotary motion from the wheel 85 to the control 87, but yet loosely enough to allow slippage to occur between these components when the iris 88 has been dilated or contracted to its maximum extent. The use of such a loose-fitting, flexible belt 90 in lieu of spur gears or some other type of drive linkage prevents an overload condition from occurring within the motor 60 if the power is left on after the iris has been dilated or contracted to its maximum extent.
With specific reference to FIG. 4, the television camera 57 includes the previously mentioned lens assembly 92. In the preferred embodiment, a lens assembly 92 with a 7.5 millimeter focal length is used, which allows the front end of the camera assemblies 7a,7b to be placed approximately 1.5 inches (3.81 centimeters) away from the electric arc generated by the tungsten electrode 14. Such close positioning between the camera assemblies 5a and 5b and the tungsten electrode 14 advantageously gives the torch assembly 13 a fairly compact configuration which allows it to be manipulated in relatively small spaces with a minimum amount of mechanical interference. Of course, cameras with longer focal lengths (such as 15 millimeters) can be used when a compact weld head configuration is not necessary. The increase in the distance between the camera assemblies and the end of the tungsten electrode 14 from 1.5 to 3 inches (7.6 centimeters) has the advantage of reducing the heat load upon the housing 55. Disposed behind the lens assembly 92 is an image sensing circuit 94 which is preferably, as has been indicated earlier, a CCD pixel array. Disposed over the image sensing circuit 94 in an RGB filter for balancing the color sensitivity of the circuit 94 so that it "sees" colors in the same porportions as the human eye, which is most sensitive to green light and least sensitive to blue light.
With reference now to FIGS. 4 and 5, a regionalized filter assembly 96 is disposed between the lens assembly 92 and the image sensing circuit 94. This filter assembly 96 is preferably formed from a stack of filter elements 98, 99 and 100 which are mounted in overlapping and concentric relationship with one another by means of filter retainer assembly 102. Filter retainer assembly 102 is formed from a retainer ring 102.5 at its distal end, and a telescopic barrel 103 at is proximal end. This telescopic barrel 103 receives circular sleeve 104 and is slidably movable along the optical axis of the camera 57.
The television camera 57 further includes a cable drive assembly 108 for sliding the filter assembly 96 either closer or further away from the image sensing circuit 94 in order to change the apparent size of the centrally located darkened region of the filter elements 98, 99 and 100 with respect to the image projected onto the image sensing circuit 94 by the lens assembly 92. To this end, the cable drive assembly 108 is provided with a lead screw 110 whose ends are rotatably mounted within a pair of screw mounts 112 and 114. A riding nut 116 is threadedly engaged to the lead screw 110 such that it moves along the longitudinal axis of the lead screw 110 when lead screw 110 is rotated. A bracket 118 interconnects the riding nut 116 with the telescopic barrel 103 through a slot in the cylindrical body 58 of the television camera 57. A drive cable 119 is coupled onto the proximal end of the lead screw 110. In operation, the drive cable 119 may be connected to either a reversible DC electric motor, or may be turned by hand in order to move the stacked array of filter elements 98, 99 and 100 a desired distance with respect to the image sensing circuit 94.
With reference to FIGS. 5 and 6, each of the filter elements 98, 99 and 100 of the filter assembly 96 includes a central region 120 of low light transmission that is surrounded by a peripheral region 122 of high light transmission. In the preferred embodiment, peripheral region 122 is as close to transparent as possible, while the central region 120 should transmit only about 1/1000th of the light that impinges upon it. Moreover, the filter medium that forms the filter elements 98, 99 and 100 should be easy to work with, and not apt to cause stray refractions that could mar the image projected on to the image sensing circuit 94 by the lens assembly 92. The applicant has surprisingly found that exposed and developed Tri-X-Pan manufactured by KODAK Corporation located in Rochester, N.Y., works extremely well for this purpose. It is a relatively simple matter to photograph a series of white dots of varying diameters placed within a black background to create a negative having a series of black dots of different diameters surrounded by a transparent background. Each small black dot on the negative is precisely centered within a hole punching machine to create a circular filter element as shown in FIG. 5. In the preferred embodiment, the central region 120 of filter element 98 is 1/16th inches (1.5875 millimeters) in diameter, while the central regions 120 of filter elements 99 and 100 are approximately 1/24th (1.0583316 millimeters) and 1/32nd (0.79375 millimeters) of an inch in diameter apiece, respectively.
With reference now to FIGS. 6, 7 and 8, when the filter elements 98, 99 and 100 are stacked over one another with their central regions 120 concentrically arranged, an aggregate region 124 of low light transmission is formed which is visible at the center portion of the resulting image. This aggregate region 124 includes an outer zone 126, a middle zone 128 and a center zone 130 of constantly increasing light filtration. Specifically, the outer zone 126 transmits approximately 1/1000th of the light which impinges upon it, while the middle and center zones 128 and 130 transmit approximately 1/10,000th and 1/100,000th percent of this light respectively. Due to the high transmissivity of the peripheral region 122 of each of the filter elements 98, 99 and, the aggregate peripheral region 131 transmits essentially all of the light that impinges upon it. The filter elements 98, 99 and 100 should be kept out of the focal plane of the lens assembly 92. A comparison of how the transitions appear between the zones 126, 128 and 130 when the filter elements are within and without the focal plane of the lens assembly 92 may be made by comparing these transitions in FIGS. 7 and 8. When the filter elements 98, 99 and 100 are positioned within the focal plane, the concentric zones 126, 128 and 130 project a "bullseye target" type image over the arc and weld puddle which is optically distracting. However, when these filter elements are positioned outside of the focal plane, the harsh edges of the transition are softened as though they were vignetted.
In operation, the television camera assemblies 5a and 5b are switched on, and the bracket 63 of each of these assemblies is adjusted so that the aggregate region 124 of low light transmission covers the region surrounding the tip end of the electrode 14 of the torch assembly 13. The apparent size of the aggregate region 124 of low light transmission may be varied between the limits indicated in FIG. 6 in either one of two ways. First, the mechanical iris 88 may be opened or closed by actuation of the iris drive motor 60. As the iris 88 is closed, the column of light passing through the lens assembly 92 is narrowed (as is indicated by the dotted lines) which in turn causes the lens assembly 92 to focus more light through the aggregate region 124, thereby making this region appear larger in the resulting image. Alternatively, the drive cable 119 of the cable drive assembly 108 may be manually or remotely turned, thereby moving the filter assembly 96 closer to or farther away from the image sensing circuit 94. The apparent size of the aggregate region 124 of low light transmission will appear larger as the filter assembly 96 is moved closer toward the image sensing circuit 94.
Next, the operator strikes an arc with the electrode 14 of the torch assembly 13. At this juncture, the operator makes a final adjustment with respect to the apparent size of the aggregate region 124 so that the darkest central zone 130 just covers the bright arc. The welding operation is then commenced with the wire feeder 34 feeding in metal wire 132 of an appropriate composition to form a weld bead 134 on the workpiece 2. The system 1 allows the operator to easily see the weld puddle 136 created by the arc, and the wettability of the leading edge of the liquid metal formed by the arc. Additionally, both the position of the electrode 13 relative to the workpiece 3 may be observed, as well as its condition. The use of a color television camera 57 advantageously allows the welding operator to observe the relative color of the completed weld bead 134 on the workpiece 3 and to better evaluate the quality of this bead 134 than would be possible if only a black and white television camera were used.
To better enhance the quality of this video image displayed over the television monitors 8a and 8b, the current pulser 11 may be used to supply pulsed power to the torch assembly 13 as is illustrated in the graph of FIG. 9, and the transmission of the video signal from the image processing circuitry 7 of the television monitors 8a,8b maybe synchronously interrupted with the high points in the current curve by means of the gating circuit 9 so that the monitors only generate an image on their screens when the current is at a low point. In the instant example, the system operator adjusts the current output of the power supply 16 to 400 amps. Next, the current limit control 51a of the current pulser 11 is adjusted so that the output of this device fluctuates between 50 amps and 400 amps in a square wave pattern. Next, the frequency control 51b of the current pulser 11 is adjusted so that the frequency of the square wave illustrated in FIG. 9 is 1/60th of a second. The control signal generated by the frequency control 51b is connected to the input of the gating circuit 9. Appropriate digital circuitry is provided within the gating circuit 9 so that the output of this device is a square wave signal which serves to interrupt the video signal transmitted from the imaging processing circuitry 7 to the television monitors 8a,8b whenever the current is at a level of 400 amps which in turn causes the imaging processing circuitry 7 to be at an "on" state only when the current level is at 50 amps. As the resulting electric arc is much dimmer at 50 amps than at 400 amps, the quality of the resulting image on the television monitors 8a and 8b is improved.
While the preferred embodiment of the system 1 shows the filter assembly 96 behind the lens assembly 92, it may alternatively be placed in front of the lens assembly 92, preferably out of the objective focal plane to soften the transitions between the filtered regions. | The invention is both a system and method for video monitoring a metal working process which involves the generation of an intense point source of light near or on a workpiece, such as an electric arc welding process. The system comprises a lens assembly for projecting an image of the point source of light and the area of the workpiece being worked onto the image sensing circuit of a television camera, a filter assembly having at least one filter element that includes both a central region of low light transmission for dimming the image of the point source of light projected onto the image sensing circuit, and a peripheral region of high light transmission for freely transmitting the image of the background surrounding the point source, and a mechanism for adjusting the apparent size of the central region of low light transmission relative to the image. In the preferred embodiment, an iris disposed within the lens assembly is used to adjust the apparent size of the central region so that it just barely covers the bright arc generated by the torch assembly so that the weld puddle and surrounding area of the workpiece is clearly visible and brightly illuminated in the resulting video image. The system provides a clear, bright and well balanced image of a welding operation without the severe and obscuring contrasts associated with prior art monitoring devices. | 7 |
FIELD OF THE INVENTION
The present invention is directed to cutting blades for cutting gears and related toothed articles.
BACKGROUND OF THE INVENTION
In the manufacture of bevel and hypoid gears it is well known to utilize face mill type cutters in both generating and non-generating gear cutting processes. In face mill cutters, cutting blades are arranged in the cutter head such that one tooth slot is formed with each cutting cycle (e.g. plunge, or feed-in and roll) of the cutter. The cutter must be withdrawn and the workpiece indexed to the next tooth slot position in order to form the next tooth slot. With face milling, all cutting blades of the face mill cutter pass through the tooth slot during the cycle until the desired slot geometry (and hence, tooth flank geometry) is formed.
Face milling tools include a plurality of blades projecting from a front face or periphery of a cutter head wherein the cutting blades are arranged in one or more concentric circles about an axis of rotation of the cutter head. Cutting blades may be of the type commonly referred to as stick-type or bar blades made of a length of bar stock (for example, U.S. Pat. No. 4,137,001 to Fountain; U.S. Pat. No. 4,575,285 to Blakesley; U.S. Pat. No. 6,120,217 to Stadtfeld et al.; or U.S. Pat. No. 3,760,476 to Kotthaus). Cutting blades may also be of the form-relieved type (for example, U.S. Pat. No. 3,192,604 to Whitmore or U.S. Pat. No. 3,268,980 to Blakesley et al.). Either type may be made of suitable material such as high speed steel (HSS) or carbide and the blades may have one or more surfaces coated with wear enhancing coatings such as TiN, TIAlN, AlTiN, etc. as is known by the artisan.
Typically in face mill cutters, a set of “inside” blades for cutting convex flanks of work gear teeth are arranged at a first radius from the cutter head axis, and a set of “outside” blades for cutting concave flanks within the same tooth space are arranged at a second larger radius. Examples of this type of cutter can be seen in U.S. Pat. No. 2,024,494 to Wildhaber or U.S. Pat. No. 4,137,001 to Fountain. In some cutters, separate bottom blades are included to cut the bottom of a tooth slot (e.g. U.S. Pat. No. 3,760,476 to Kotthaus) while in other cutters, the inside and outside cutting blades include cutting portions which also cut at the bottom of the tooth slot (for example, U.S. Pat. No. 4,278,370 to Spear). Alternatively, cutting blades that cut the convex side, concave side and the bottom of a tooth slot (i.e. the entire tooth slot) may also be utilized. Examples of this type of cutter are shown in U.S. Pat. No. 1,236,834 to Gleason; U.S. Pat. No. 1,667,299 to Wildhaber; or WO 2004/103624 to Ribbeck.
In producing gears with cutters having inside and outside cutting blades, uneven wear of the cutting blades is of significant concern as certain areas of the blades experience wear and break down earlier than other areas. With cutters having blades that cut the entire tooth slot, large chips tend to form which can result in chip flow problems and truing of such cutters cannot be accomplished since repositioning a cutting blade to true one cutting side of the cutting blade will also affect the position of other cutting side likely causing the other side to shift out of an optimal cutting position.
SUMMARY OF THE INVENTION
The present invention is directed to a cutting blade for face milling wherein the cutting blade is constructed to cut a predetermined final dimension of a tooth slot along a portion of the cutting end (i.e. the primary portion) of the blade and to cut the remainder of the tooth slot at an amount less that the predetermined final dimension of the tooth slot along the remaining portion of the cutting end (i.e. the secondary portion). The construction of the inventive cutting blade provides sharing of the cutting load amongst the blade cutting edges and also provides sufficient clearance in the tooth slot whereby the cutting blade can be repositioned to allow truing of the cutter, particularly with respect to the primary portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a face milling process to produce a gear.
FIG. 2 is a representative diagram of a gear tooth slot.
FIG. 3 illustrates the cutting positions of one type of prior art cutting blades for cutting a gear during face milling.
FIG. 4 illustrates a prior art cutting blade for cutting the entire tooth slot of a gear during face milling.
FIG. 5 shows an inventive cutting blade positioned to remove a portion of stock material from a tooth slot.
FIG. 6 shows an inventive cutting blade positioned to remove another portion of stock material from a tooth slot.
FIG. 7 shows the cutting positions of the cutting blades of FIG. 5 and FIG. 6 for cutting a gear during face milling.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The details of the present invention will now be discussed with reference to preferred embodiments which represent the invention by way of example only. In the drawings, the same reference numbers will be utilized to refer to like elements.
FIG. 1 depicts a face milling process utilizing inside and outside cutting blades. A tooth slot 2 is being formed between opposing tooth surfaces 4 , 6 of adjacent teeth 8 , 10 of a workpiece 20 such as, for example, a spiral bevel gear. A face mill cutter 22 , having alternating inside cutting blades 24 and outside cutting blades 26 (only a portion shown) arranged about a circle with a center C, rotates in direction R such that all cutting blades on the cutter pass through slot 2 as the cutter is fed relative to the workpiece to a predetermined full depth position. Inside cutting blades 24 cut the lengthwise convex shaped tooth surface 6 of tooth 10 while outside cutting blades 26 cut the lengthwise concave shaped tooth surface 4 of tooth 8 .
FIG. 2 illustrates the general cross sectional form of tooth slot 2 in a gear, such as the gear 20 of FIG. 1 . The tooth slot 2 comprises opposite sides 4 , 6 of adjacent teeth 8 , 10 and further includes a bottom portion 12 and radius portions 14 and 16 .
FIG. 3 shows, in an overlapping view, the respective positions of inside cutting blades 24 and outside cutting blades 26 of the prior art as they pass sequentially through the slot 2 . It can be seen that inside cutting blade 24 includes a pressure angle cutting edge 30 , for cutting the convex surface 6 of tooth 10 , and further includes a tip edge 32 for cutting a portion of the bottom 12 of the slot 2 as well as a pressure radius edge portion 34 for cutting corresponding tooth slot radius 16 . Inside cutting blade 24 also includes clearance side 36 which does not cut a tooth surface. It can also be seen that outside cutting blade 26 includes a pressure angle cutting edge 40 , for cutting the concave surface 4 of tooth 8 , and further includes a tip edge 42 for cutting a portion of the bottom 12 of the slot 2 as well as a pressure radius edge portion 44 for cutting corresponding tooth slot radius 14 . Outside cutting blade 26 also includes a clearance side 46 .
FIG. 4 shows another prior art arrangement for face milling wherein each cutting blade 50 passing through a tooth slot 2 cuts both sides 4 , 6 of the tooth slot as well as the bottom 12 and radius portions 14 , 16 of the tooth slot 2 . In other words, the cutting blade of FIG. 4 is a full-slot blade in that each cutting blade 50 cuts with both side cutting edges 52 , 54 as well as with a tip cutting edge 56 and radius cutting edge portions 58 , 59 .
As previously mentioned, with cutters having inside and outside cutting blades as shown in FIG. 3 , uneven wear of the cutting blades is of significant concern as areas of the blades, such as the pressure radius cutting edge portions 34 , 44 in particular, experience wear and break down earlier than other areas due to high cutting loads. With cutters having blades that cut the entire tooth slot, as in FIG. 4 for example, large chips tend to form which can result in chip flow problems. Also, truing of such cutters cannot be accomplished since repositioning a cutting blade to true one cutting side edge of the cutting blade will also affect the other cutting side edge likely causing the other side to shift out of an optimal cutting position. Furthermore, cutting blades having cutting edges on both sides usually include a zero front rake angle which is not optimal for cutting.
The inventors have discovered that by including a more encompassing cutting region on a cutting blade, one that dimensionally approaches a full-slot cutting blade, but provides some clearance on one side of the cutting blade, uneven blade wear is reduced, the cutting blade remains capable of being trued, and a front rake angle and/or hook angle can be included.
The inventive cutting blade is shown in FIGS. 5-7 . In FIG. 5 , an inside cutting blade 60 is illustrated comprising a pressure angle cutting edge 62 , a pressure radius cutting edge portion 64 and tip cutting edge portion 66 (collectively, the “primary” cutting edge portion) which together cut, respectively, side 6 , radius 16 and the entire bottom portion 12 of slot 2 to a predetermined form or geometry, for example, a desired rough form (stock allowance left for subsequent grinding) or a desired finished form, either of which may be understood as being exemplified by the form of tooth slot 2 in FIG. 2 . It is to be understood that the present invention is not limited to the slot 2 form but is applicable to any tooth slot form or geometry produced by generated or non-generated face milling.
The inventive cutting blade also includes another radius cutting portion 68 (i.e. the clearance radius cutting edge) that is of a dimension less than that required to form the predetermined radius 14 . Therefore, clearance radius cutting edge 68 “roughs out” the other tooth slot radius 14 to a form near to the predetermined form but leaves a distance 67 between the predetermined tooth slot radius position 14 and the clearance radius cutting edge 68 that comprises excess stock material. Cutting blade 60 also includes clearance side 69 which may also be a cutting edge, along all or part of its length, to rough cut the other flank surface 4 of tooth slot 2 . The clearance radius cutting edge 68 and any cutting edge on clearance side 69 define a “secondary” cutting edge portion.
Of course, the discussion above likewise applies to outside cutting blade 70 as shown in FIG. 6 wherein the cutting blade comprises pressure angle cutting edge 72 , radius cutting edge 74 and tip cutting edge 76 (collectively, the “primary” cutting edge portion) which together cut, respectively, side 4 , radius 14 and the entire bottom portion 12 of slot 2 to a predetermined form or dimension, for example, a desired rough form (stock allowance left for subsequent grinding) or a desired finished form either of which also may be understood as being exemplified by the form of tooth slot 2 in FIG. 2 .
The inventive cutting blade 70 also includes another radius cutting edge portion 78 (i.e. the clearance radius cutting edge) that is of a dimension less than that required to form the predetermined radius 16 . Therefore, clearance radius cutting edge 78 “roughs out” the other tooth slot radius 16 to a form near to the predetermined form but leaves a distance 77 between the predetermined tooth slot radius position 16 and the clearance radius cutting edge 78 that comprises excess stock material. Cutting blade 60 also includes clearance side 69 which may also be a cutting edge, along all or part of its length, to rough cut the other flank surface of tooth slot 2 . The clearance radius cutting edge 78 and any cutting edge on clearance side 79 define a “secondary” cutting edge portion.
The amount of stock material remaining (i.e. the distance) after cutting at the roughed-out tooth slot radius (e.g. 67 in FIG. 5 or 77 in FIG. 6 ) may be any amount based on parameters such as the gear and/or cutting blade design including adequate blade strength and/or cutting edge support, wear tendencies of the cutting blade, whether the gear will undergo a finishing operation, the amount of slot tolerance desired for truing, etc. However, a preferred amount of stock material remaining in the roughed-out tooth slot radius after cutting is about 0.002-0.0002 inch (0.051-0.0051 mm).
The clearance edges 69 and 79 are shown with different configurations but the present invention is not limited thereto. The clearance edge may be straight as shown in FIG. 5 , curved, or may more closely follow the contour of the tooth profile surface, as shown in FIG. 6 , along all or only a portion of the flank profile. If desired, the clearance cutting edge may be spaced from the tooth flank profile at a distance the same or about the same as that of distance 67 or 77 , as shown in phantom in FIGS. 5 and 6 respectively, or it may vary in distance from the tooth flank profile surface. The clearance radius cutting edge ( 68 , 78 ) as well as any clearance side cutting edge (e.g. 69 , 79 ) do not produce the final desired gear geometry.
With the inventive configuration, the pressure angle cutting edge and pressure radius cutting edge cut a tooth slot in the same manner as is known in the art. However, the expanded tip edge as well as the clearance radius cutting edge, and optionally, the clearance cutting edge itself, provide for a balanced load on the cutting blades. For example, looking at prior art FIG. 3 , as either inside or outside cutting blade passes through the tooth slot, nearly all cutting occurs at the pressure angle edge, radius edge portion and tip portion of a cutting blade. However, the region between a respective clearance edge and the opposite side of the tooth slot is not contacted by the cutting blade. The next cutting blade through the tooth slot encounters the same conditions but only on the other side of the slot. In either instance, cutting loads in the vicinity of the pressure side radius edge are high and blade-wear in this region is more prevalent. With the present invention, each cutting blade coming through the tooth slot removes about the same amount of stock material along a greater portion of the cutting blade. Hence, cutting loads are more even and reduced overall.
Also as stated above, with the secondary cutting edge portion not cutting to the final desired geometry of a tooth slot, sufficient blade clearance is provided (e.g. distance 67 or 77 ) such that the inventive cutting blade can be trued. The pressure angle cutting edge can be adjusted to a proper position without adversely affecting the function or purpose of the clearance cutting edge or clearance radius cutting edge (which is not possible with full-slot cutting blades) due to the diminished dimension of the cutting blade at the clearance radius cutting edges 68 , 78 . The distance 67 , 77 between the location of the actual cut and the predetermined or desired location of the tooth slot allow for movement of the cutting blade thus providing the opportunity for truing.
While the invention has been described with reference to preferred embodiments it is to be understood that the invention is not limited to the particulars thereof. The present invention is intended to include modifications which would be apparent to those skilled in the art to which the subject matter pertains without deviating from the spirit and scope of the appended claims. | A cutting blade for face milling wherein the cutting blade is constructed to cut a predetermined final dimension of a tooth slot along a portion of the cutting end (i.e. the primary cutting edge portion) of the blade and to cut the remainder of the tooth slot at an amount less that the predetermined final dimension of the tooth slot along the remaining portion (i.e. the secondary cutting edge portion) of the cutting end. The construction of the inventive cutting blade provides sharing of the cutting load amongst the blade cutting edges and also provides sufficient clearance in the tooth slot whereby the cutting blade can be repositioned to allow truing of the cutter, particularly with respect to the primary portion. | 8 |
TECHNICAL FIELD
This invention relates generally to printing machines and, more particularly, to a register control device for a printing machine.
BACKGROUND OF THE INVENTION
In a sheet-fed offset printing machine, a printing plate is fastened on a plate cylinder by means of a clamping rail allocated to the leading edge of the printing plate and a clamping rail allocated to the trailing edge. An example of such a printing machine may be seen in U.S. Pat. No. 5,511,478 (DE 43 39 344 C1) which discloses a device for the automatic changing of printing plates in a printing machine. Here, a printing plate, which is to be inserted, has certain built in guards to stop movement and a guide device to assist its contact with the cylinder and insertion into the clamping rail of the edges. After this plate has been inserted into the clamping rail and the plate's leading edge has been clamped, the plate is drawn onto the cylinder by the latter being rotated forwards. During insertion into the leading edge clamping rail and the drawing process, the central or rear part of the printing plate still makes contact with the guard.
To assure high print quality, printing plates are usually fitted to the plate cylinder in a precise location using a register system. For example, U.S. Pat. No. 5,383,402 (EP 0 551 976 A1) discloses a register system for mounting a plate on a plate cylinder that includes a plate lockup device, reference pins and a lamp. The plate lockup device is provided in a gap formed in the circumference surface of the plate cylinder. The reference pins are electrically rendered conductive by contacting an insertion end of a plate inserted into the plate lockup device, thereby detecting insertion of the plate. The lamp confirms and indicates insertion of the plate from an output from the reference pins thereby allowing a manual installation of a printing plate to visually verified.
While the register system disclosed in this patent does work for its intended purpose, it does suffer disadvantages. For example, the register system suffers the disadvantage of requiring extra space for the contact areas on the cylinder and for the rollers on the frame. Additionally, these rollers also increase outlay on construction. Still further, any soiling of the contact areas or the contacts/rollers could result in an erroneous signal transmission.
SUMMARY OF THE INVENTION
To overcome these disadvantages, the present invention is generally realized in an expanded register control system for a cylinder of a printing machine. The system is adapted to form a simple electrical circuit and contains register pins that are fitted so as to be electrically insulated with respect to the printing machine cylinder. Signals are generated by a signal generator that is connected to the register pins via the cylinder. When a new printing plate is inserted a signal is sent that contains a pulse train to the register pins. The pulse should be comprised of a predefined frequency and duration. If the printing plate is in the in-register position, i.e. connected properly to the cylinder, the printing plate will assume the potential/pulse train of the register pins.
Using an electrical contact, the pulse train assumed by the printing plate is transferred to a control system. Within the control signal, the pulse train is evaluated and compared to a predefined potential. If the pulse train assumed by the printing plate matches the predefined potential, then the plate is known to have been inserted correctly. Otherwise, the system will assume the printing plate is not in the correct position.
BRIEF DESCRIPTION OF THE DRAWINGS
While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
FIG. 1 is a diagram that shows the basic circuit of the present invention; and
FIG. 2 is a diagram that shows the arrangement of a wiping contact and its action on the rear side of the printing plate.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the figures, wherein like references refer to like elements, there is illustrated in FIG. 1 an example of a printing machine in which the present invention resides. In this regard, FIG. 1 shows the position of the printing plate 1 in its isolated state without any contact with the register pins 2.1 and 2.2. The register pins 2.1 and 2.2 are electrically insulated inside the cylinder 1. The cylinder 1, which may be a plate cylinder, printing-forme, etc, has the two register pins 2.1 and 2.2 in a clamping rail (not shown). A power supply 3 is also within the cylinder 1, as well as a signal generator 4. The power supply may be any source of power like a battery or rechargeable battery, and it is connected to the signal generator 4. The clamping rail is assigned to the leading edge of the printing plate 5. The register pins being fitted so that they can be electronically insulated with respect to the clamping rail and the entire cylinder 1. The register pins 2.1 and 2.2 have a signal connection to a signal generator 4. The signal is in the form of pulses. The printing plate 5 is inserted into the cylinder 1. During the insertion process, the signal generator 4 brings the register pins 2.1 and 2.2 to predefined electric potentials.
On the leading edge of the cylinder 1 are two U-shaped grooved notches, which match up with the register pins 2.1 and 2.2 in a manner known to those skilled in the art. The rear side of the printing plate 5 is assigned to the contact 6. The potential of the printing plate 5 can then be read via the contact 6 and sent to an evaluation unit 7. The evaluation unit 7 is fixed to the frame and has a signal connection to an indicator 9. The evaluation unit 7 is also connected to a control system 8. The control system 8 monitors the entire printing plate changing process; in particular to the opening and closing of the leading edge clamping rail in the cylinder 1 which it may also trigger. The pulses from the signal generator 4 are sent in such a way that the signal that reaches evaluation unit 7 can determine which register pin 2.1 and/or 2.2 that printing plate 5 is resting in-register and which register pin 2.1 and/or 2.2 it is not resting in-register.
FIG. 2 shows a side view of part of the cylinder 1 with the printing plate 5 resting on the electrically insulated register pins 2.1 and 2.2. The printing plate 5 is inserted into the cylinder 1 through a guard (not shown) via a roller 10. The roller 10 interacts with the printing side of the printing plate 5 and is generally made from electrically insulated materials. The contact 6 is fitted opposite of the roller 10 in the guard and interacts with the uncoated rear side of the printing plate 5. The contact 6 is in the form of a wiping contact, which is an electrically conductive roller or brush. The contact 6 can register the electric potential of the register pins 2.1 and 2.2 and forward that information to the stationary evaluation unit 7. The stationary unit establishes the in-register position by measuring the electric potential of the printing plate 5 and comparing it to the applied potential of the register pins 2.1 and 2.2. If the printing plate 5 was inserted correctly, the clamping rail in the cylinder 1 should close and the printing plate 5 should draw onto the cylinder 1.
In the preferred embodiment of the invention, the register pins are electrically insulated with respect to the clamping rail and the entire cylinder. A signal generator located within the cylinder should bring the register pins to a specific potential via pulses (coded signals) that are of a predefined frequency and duration. The signal generator can be connected to any sort of power supply that can provide it the necessary power to generate the pulses. The signal generator may be modified so that when the two register pins are in the cylinder the pulses to each register pin are different. The printing plate, which is electrically insulated with respect to the cylinder and the clamping rails, should assume the potential of the pulse train sent to one of the individual register pins. It should assume the potential of the register pin that it first comes in contact with. A stationary evaluation unit is connected via a contact to the printing plate. The contact is usually near the rear end of the printing plate and may be a wiping contact, electrically conductive roller, electrically conductive brush, or a similar material. Thus, this stationary evaluation unit may be able to establish which of the register pins the printing plate first rests in-register and eventually whether both register pins are in-register. When both register pins are in-register, the control system connected to the evaluation unit can trigger the clamping operation. The evaluation unit may also be connected to other devices, such as an indicator and/or a control system. The indicator can determine and display whether the printing plate is resting in-register and whether each of the register pins are in the proper position. The control system may monitor the entire printing plate change operation, and it may initiate and terminate this process.
The process of reading the signals is done near the read end of the printing plate. Electrically conductive materials such as rollers, wipers, or brushes can be used to read the signal. Preferably, this invention is used with a printing plate changer, which is known to those skilled in the art. The printing plate that is to be inserted should be guided by a guard before it is changed, while it is being inserted, and while it is being drawn onto a cylinder.
In a sheet-fed offset printing machine, aluminum printing plates, which are uncoated on the non-printing rear side, may be used. A printing plate changer can be constructed along the guidelines known to those skilled in the art and combined with the present invention by fitting an electrically conductive object such as a roller, wiping contact, or brush. This object is arranged in such a way with the guard of the printing plate changer that the electrical potential of the printing plate can be measured off the rear side of the printing plate. The signal is sent to the stationary evaluation and control unit. The parts, which guide the printing plate, are made of electrically insulated design such as electrically non-conducive plastic.
All of the references cited herein, including patents, patent applications, and publications, are hereby incorporated in their entireties by reference.
In view of the many possible embodiments to which the principles of this invention may be applied, it should be recognized that the embodiment described herein with respect to the drawing figures is meant to be illustrative only and should not be taken as limiting the scope of invention. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof. | The present invention generally describes register control equipment for the cylinder of a printing machine. It specifically pertains to the printing plate of sheet-fed offset printing machine that has fitted register pins. The register pins are electrically insulated with respect to the cylinder and emit a signal when a printing plate is resting in register on one or more of the pins. The signal is communicated to a stationary evaluation unit by an electrical contact adapted to contact the printing plate. The evaluation unit uses the communicated signal to determine whether or not insertion was properly performed. | 8 |
BACKGROUND OF THE INVENTION
The present invention refers to a differential pinion assembly, especially suitable for use in a motor-vehicle transmission, having a simple and very compact structure and where the friction between the relative movement members is substantially a rolling friction.
The differential units for motor-vehicles are adapted to transmit the movement from the driving shaft to the two axleshafts and notoriously comprise a box in the inside of which rotates a differential carrier actuated by a toothed driving pinion engaging with a crown gear solid with the differential carrier. The differential carrier is supported during rotation on the box by means of a pair of antifriction bearings, usually taper roller bearings onto which the radial and axial loads applied to the differential carrier by the pinion are discharged. Inside the differential carrier are located satellite gears, rotatable relative to the same and mating with two planetary gears with each of which an axle shaft is solid. The aforesaid satellite and planetary gears are normally rotatable with sliding friction, the former round a pin located inside the differential carrier, the latter in appropriate seats of the differential carrier. The driving toothed pinion is solid with a shaft, this too supported by a pair of antifriction bearings, normally taper roller bearings, and transmission of the movement from the driving shaft to the latter shaft takes place by means of two flange half-couplings, one of which, fitted with a splined hub, mates with the pinion shaft.
The differential units of the above described type show some inconveniences.
First of all, their structure is rather complex, and their assembling and disassembling involves lengthy and delicate operations. In effect, since for supporting the differential carrier and the pinion shaft normal antifriction bearings are used, when fitting these special measures and precautions are to be taken, and seats, shoulders, locking and adjusting elements as well as other parts of like kind must be provided. Moreover, the relative movement between some parts of the unit, for instance between the planetary gears and the differential carrier is pure sliding movement, with rather high friction values. Lastly, during operation unbalancing centrifugal forces may arise due to the presence of eccentricity in the fitting of the two above mentioned half-couplings that connect the transmission shaft and the unit.
SUMMARY OF THE INVENTION
The object of this invention is to provide a differential pinion assembly which is adapted to transmit the movement to two axle-shafts and which is substantially exempt from the above mentioned inconveniences.
The differential pinion assembly according to the invention, comprises: a box in the inside of which rotates a differential carrier actuated by a driving toothed pinion engaging with a crown gear solid with the differential carrier, said differential carrier carrying satellite gears rotatable relative to it and mating with corresponding planetary gears with each of which one of the aforesaid axle-shafts is solid, a first row of rolling elements interposed and coupled between each of said planetary gears and the above mentioned differential carrier, and a second row of rolling elements interposed and coupled between said planetary gear and said box.
In the differential pinion assembly according to the invention the aforesaid toothed pinion is solid with a driving shaft supported during its rotation relative to the box by means of a pair of row of rolling elements rolling on raceways provided on an annular element fastened to said box: according to a further characteristic of the invention, the assembly comprises two rings fitted to said shaft, on each of which a raceway is provided for said rolling elements, said rings being brought into contact with each other and against a shoulder of the shaft with the employment of thrust means, and the ring located farther away from the pinion being equipped with axial grooves adapted to mate with corresponding axial projections of said shaft and with axial holes apt to make possible the connection of the ring directly with the transmission shaft, by which the differential pinion assembly is driven.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, a description is given below, by may of example, of some particular forms of embodiment of the same with reference to the attached drawings.
FIG. 1 is a sectional view of the differential pinion assembly according to the invention.
FIG. 2 is a detail of a sectional view, similar to that of FIG. 1, of a differential pinion assembly according to a second form of embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The differential pinion assembly according to the invention comprises substantially a box the whole of which is designated by numeral 1, and in the inside of which the components of the assembly are housed. The assembly comprises a differential carrier 2, rotatably mounted, as described in the following pages, in the inside of the box and on which is fixed a crown gear 3 engaging with a driving pinion 4 solid with a shaft 5 to which the movement is imparted by the transmission shaft (not shown in the figure) which provides a source of mechanical rotary power.
The differential carrier 2, which has substantially the form of a revolving solid generated by the rotation of a plane figure such as that shown in the section of FIG. 1, comprises substantially a body 6 and a flange 7, apt to make possible the fastening, for instance by means of screws 8, of the crown gear 3: the centering of this relative to the differential carrier is ensured by the mating of its inner cylindrical surface with a corresponding cylindrical surface 9 of the body 6.
In the inner recess 12 of the differential carrier are arranged satellite gears 13 rotatably mounted on a pin 14 fitted in corresponding holes of the body 6. The satellite gears engage with two planetary gears 15, each of which has a hub 15a and is adapted to be connected, coaxially by known technical means, for instance by means of grooves 16 to receive interfitting ribs or projections on a corresponding axleshaft (not shown in the figure) which must be driven by the differential pinion assembly according to the invention. A first row of rolling bearing elements 17, for instance balls, is arranged between the outer periphery of the hub of each planetary gear 15 and the differential carrier, to guide the carrier for rotation about the common axes of the planetary gears; and a second row of rolling elements 18, for instance again a row of balls, is also arranged between the outer periphery of the hub of each planetary gear and an adjacent annular element 19 which in its turn is fixed, in any convenient manner, to the box 1 of the differential pinion assembly, to guide rotation of the planetary gears with respect to the box 1.
The rolling elements of the first row 17 are adapted to roll on raceways 17a and 17b provided on the differential carrier 2 and on the hubs of planetary gears 15 respectively, and the rolling elements of the other row 18 are adapted to roll on raceways 18a and 18b, provided on the annular elements 19 and on the hubs of the planetary gears respectively. The raceways 17a on the carrier body 2 also define the annular openings through which the planetary gear hubs 15a extend. The form of the above mentioned raceways is such, that the straight lines which run through the contact points between each rolling element and its raceway and which are perpendicular to tangents of the rolling element and raceway mating surfaces, are inclined, at an oblique angle with respect to the rotation axis; or with respect to the roll angle of the planetary gears, through an angle equal to, or other than, 90°. Moreover, the inclination of the straight lines with respect to the rolling elements of the first rows 17, is opposite in direction to the inclination of the straight lines relative to the rolling elements of the second rows of balls 18. Otherwise stated, annular raceways 18a and 17a are concavely shaped to conform to the shape of the bearing elements 18 and 17. The raceways 18a and 17a are oriented to face obliquely inwardly and axially of the gear hub 15a, and such raceways are oppositely oriented so as to face obliquely in opposite axial directions. The corresponding raceways 18b and 17b on the gear hub 15a are disposed opposite raceways 18a and 17a and also concavely shaped and oriented to face obliquely outwardly and axially of the hub, Such raceways 18b and 17b include portions which are oppositely oriented to face obliquely in opposite axial directions. Accordingly, the such two rows of bearing elements are adapted to withstand both radial and axial loads, opposite in direction, acting on each planetary gear.
It is evident that the rolling elements of the rows 17 and 18 may be different from those described, for instance they may be taper rollers or elements having any other form: in this case the form of the surfaces of the corresponding raceways will have to be modified accordingly.
As can be seen, in the constructional arrangement contrived for supporting the differential carrier each planetary gear 15 projects axially to an appreciable extent from the body 2 of the differential carrier, because in the inside of this only the crown of such planetary gear is housed: the relevant hub portion, on which the raceways 17b and 18b are provided, is located outside the recess 12 and on a side of the relevant end face 20, which axially delimits the differential carrier.
Between each annular element 19 and the bottom 22 of the relevant seat an adjustment ring 23 is conveniently provided.
According to the invention, for supporting the shaft 5 with which the pinion 4 is solid, use is made of two rows of rolling elements 24, for instance balls, which are adapted to roll on corresponding raceways 24a and 24b, the former being provided on a tubular element 25, the latter on rings 26, 27 fitted on the shaft 5. The tubular element 25 is equipped with a flange 25a adapted to make possible its fastening, for instance by means of screws 28, to the box 1 and with an annular part 29 apt to accurately center it relative to the box. The ring 27 is thrust against a shoulder 32 of the shaft 5 and the ring 26 against the same by a washer 33 thrust in its turn by a nut 34 which is screwed into a threaded cylindrical portion 35 of the shaft. The ring 26 is equipped with axial groovings adapted to mate with corresponding axial groovings 36 of the shaft 5, so as to make such two parts torsionally solid: such ring may also show a portion of internal cylindrical surface which mates with the corresponding cylindrical surface of the shaft 5.
On the ring 26 there are provided axial holes 37 which are adapted to make possible the direct connection of such ring to the end flange of the transmission shaft (not shown in the figure) for driving the unit according to the invention. The form of the raceways 24a and 24b for the rolling elements 24 is, in this case too, such that the straight lines which run through the contact points of each rolling element with the respective raceway and which are perpendicular to tangents of the rolling element and raceway mating surfaces are inclined, with respect to the rotation axis of the shaft 5, through an angle other than a 90°-angle: moreover, the inclination of the straight lines relative to the rolling elements of a row is opposite in direction with respect to the inclination of the straight lines relative to the rolling elements of the other row.
Otherwise stated, all of the raceways 24a and 24b are annular about the rotation axis of shaft 5 and are concavely shaped as to receive the rows of rolling bearing elements 24. All of the raceways 24a and 24b are oriented in an oblique axial direction wherein the raceways 24a face obliquely inwardly, and the raceways 24b face obliquely outwardly. The two raceways 24b face obliquely in opposite axial directions and the two raceways 24a also face in oblique axial opposite directions. Accordingly, the two rows of rolling bearing elements 24 are captured between the raceways and the two rows are adapted to withstand, besides radial loads, axial loads in opposite directions acting on the shaft 5.
The above described differential unit operates as follows: First of all, the connection between the transmission shaft and the unit is ensured directly between the flange with which such shaft is normally equipped and the ring 26 without the need for using further connecting elements. In effect such flange is normally equipped with a set of peripheral holes, each of which can accommodate a screw which is turned into the holes 37 of the ring 26. Such constructional arrangement results not only in appreciably reduced overall dimensions but also in a perfect centering of the transmission shaft with respect to the shaft 5 with which the pinion 4 of the unit is solid: in effect, the ring 26 is found to be perfectly coaxial with the shaft 5 owing both to the mating of the cylindrical surfaces of the ring with those of the shaft, and to the possibility of accurately centering the above mentioned flange with respect to the ring.
During rotation of the shaft 5, driven by the ring 26, the rows of rolling elements 24 roll on the corresponding raceways 24a and 24b and the pinion 4 rotates thereby causing the differential carrier 2 to rotate as well. When such differential carrier rotates solidly with the planetary gears 15, as happens when the vehicle covers a rectilinear distance and consequently the two axle-shafts rotate substantially at the same angular speed, the rolling elements of the rows 17 rotate solidly with such differential carrier and perform no rolling movement relative to the respective raceways: under such operating conditions there is, instead, a rolling movement of the rolling elements of the rows 18 which accordingly support the differential carrier and the other parts solid with it. When instead a relative movement occurs between the planetary gears 15 and the differential carrier 2, as happens when the vehicle covers a curved path, besides a rotation of the rolling elements of the rows 18 there is also a rotation of the rolling elements of the rows 17, which consequently roll on the corresponding raceways of the differential carrier and of the planetary gears. Therefore it is apparent that the differential carrier with respect to the box is supported not directly by rolling elements but through the medium of the planetary gears 15. On the other hand, each planetary gear 15 is not supported directly on the differential carrier as on conventional type differential units, but partly on the differential carrier and partly directly on the box: in the former case through the row 17 of rolling elements and in the latter case through the row 18 of rolling elements. With such constructional arrangement, besides ensuring the support of the differential carrier by means of a very simple and compact structure, an additional advantage is obtained inasmuch as each planetary gear 15 is supported by means of rolling elements, contrary to what happens on differential units of the conventional type, wherein the planetary gears are supported by plain bearings placed directly inside the differential carrier.
In actual fact the two rows 17 and 18 of rolling elements located on either side of the differential carrier, behave as if they were one bearing or a set of bearings adapted to withstand the radial as well as axial loads acting on the differential carrier, whereas each row 17 and 18 behaves like an antifriction bearing adapted to withstand the loads, radial as well as axial, acting on each planetary gear 15. Furthermore, the unit according to the invention has very reduced overall dimensions. In effect, as clearly appears from the drawings and the description, the differential carrier 2 exhibits a very limited axial dimension, because it is not necessary to provide on its outside seats for the fitting of antifriction bearings adapted to support the differential carrier itself or to provide in the inside of it other seats adapted to accommodate the planetary gear hubs. Hence the maximum overall dimension of the unit, measured in the direction of the axis of the axle shafts, is very reduced: likewise, the maximum overall dimension measured in the direction of this orthogonal axis is also very reduced because, with the constructional arrangement according to the invention, the rows 24 of rolling elements may be very close. This is due to the fact that the inner raceways 24b of such rolling elements are provided on rings 26, 27 in direct contact with each other whereas the outer raceways 24a are provided on one tubular element 25.
FIG. 2 shows a form of embodiment of the invention slightly different from the above described form. In effect, the raceways 17b and 18b, instead of being provided directly on the planetary gears 15 are provided on rings 38 fastened to the planetary gears in any convenient manner. Similarly the raceways 17a are provided on rings 39 fastened to the differential carrier.
It clearly appears that other variations and modifications can be introduced in the constructional arrangement according to the invention without departing from the scope of the invention itself; in particular, it is possible to mount the differential carrier and the planetary gears in accordance with the principle of the invention using normal antifriction bearings instead of providing the rows 17 and 18 of rolling elements and the corresponding raceways on the differential carrier, on the planetary gears or on rings solid with such parts or with the box, as has been described in the forms of embodiment according to FIG. 1 and FIG. 2 respectively. | A differential pinion assembly, especially suitable for use in a motor-vehicle transmission is described.
This assembly in adapted to transmit the movement to two axle-shafts, has a simple and very compact structure and the friction between the relative movement members is substantially a rolling friction.
This assembly comprises a box in the inside of which rotates a differential carrier actuated by a driving toothed pinion engaging with a crown gear solid with the differential carrier. The differential carrier carries satellite gears rotatable relative to it and mates with corresponding planetary gears with each of which one of the aforesaid axle-shafts is solid. The main feature of this assembly is that of comprising a first row of rolling elements interposed and coupled between each of said planetary gears and the above mentioned differential carrier, as well as a second row of rolling elements interposed and coupled between said planetary gear and said box. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an impact-absorbing structure suitable for use as the structure of an aviation vehicle, such as an aircraft or a car, and to a method for producing the same.
[0003] This application is based on Japanese Patent Application No. 2009-102091, the content of which is incorporated herein by reference.
[0004] 2. Description of Related Art
[0005] Impact-absorbing structures are used as the structures of traveling bodies, such as aircraft (for example, helicopters, which are rotary-wing aircraft) and cars, to absorb impact in a collision. For example, as shown in Patent Citation 1 (described below), for helicopters, which are rotary-wing aircraft, an underfloor structure having an impact-absorbing structure has been proposed to assure passenger safety during an forced landing.
[0006] As shown in FIG. 7 , Patent Citation 1 discloses a web having a pair of face plates 101 opposed to each other with core members 103 and composite-material tubes 105 therebetween. When an impact compression load is applied to the web, fracture propagates in the axial direction of the composite-material tubes 105 , whereby the impact energy is absorbed. Furthermore, a plurality of openings are provided or the interlaminar bonding of the composite material is weakened at the peripheral walls at one end of the composite-material tubes disclosed in the aforementioned citation to reduce the failure strength at one end. This accelerates initial failure at this end, reducing an excessive initial reaction force generated when an impact is applied.
[0007] However, in the web disclosed in Patent Citation 1, which is generally referred to as a “sandwich panel”, the face plates 101 and the core members 103 are bonded by an adhesive. Therefore, the composite-material tubes 105 are also entirely fixed to the face plates 101 by an adhesive, together with the core members 103 .
[0008] If the composite-material tubes 105 are entirely fixed to the face plates 101 as in this case, the composite-material tubes 105 are restrained by the face plates 101 when an impact force is applied. As a result, the composite-material tubes 105 fracture subsequent to the failure of the existing structure, such as the face plates, whereby the impact-energy absorption capacity is decreased. Furthermore, even if progressive failure occurs, because the entirety is fixed to the face plates 101 , many of the fragments of the fractured impact-absorbing member enter the tubes. This results in a problem in that the effective length of the impact-absorbing member for absorbing the impact energy is reduced.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an impact-absorbing structure having a high impact-absorbing capacity and a method for producing the same
[0010] To solve the above-described problems, an impact-absorbing structure and a method for producing the same of the present invention employ the following solutions.
[0011] That is, an impact-absorbing structure according to an aspect of the present invention comprises a pair of flat, plate-like face plates arranged to oppose each other with a predetermined distance therebetween; a core member arranged between the face plates and fixed to the face plates; and an impact-absorbing member arranged between the face plates, at the core member side, the impact-absorbing member extending in one direction and fracturing progressively due to an impact compression force acting in the one direction. The impact-absorbing member is fixed to the face plates at one portion and is allowed to move relative to the face plates at a remaining portion.
[0012] When an impact compression force is applied to the impact-absorbing structure, the impact compression force is transmitted to the impact-absorbing member. Due to this impact compression force, progressive failure propagates in the impact-absorbing member. At this time, because one portion of the impact-absorbing member is fixed to the face plates and the remaining portion is capable of movement relative to the face plates, the progressive failure of the impact-absorbing member propagates without being impeded by the face plates. Thus, because the remaining portion capable of relative movement allows the impact-absorbing member to fracture progressively, progressive failure with a large displacement occurs. Thus, the impact energy is effectively absorbed.
[0013] The one portion where the impact-absorbing member is fixed has a length of, for example, about 15 to 30% of the overall length. Preferably, the one portion where the impact-absorbing member is fixed is provided at an end of the impact-absorbing member. More preferably, in order for the progressive failure to start in the vicinity of the position subjected to an impact compression force, the one portion to be fixed is provided at the end opposite to the end subjected to the impact compression force. For example, when the impact-absorbing structure is used as the outer wall of an aviation vehicle, the one portion to be fixed is preferably provided on the inner side that constitutes the inside of the aviation vehicle.
[0014] In the above-described impact-absorbing structure, the impact-absorbing member is tubular with the axis extending in the one direction.
[0015] The tubular shape can allow progressive failure to appropriately propagate without causing buckling failure in which a failure at one site leads to overall failure. Although the preferred cross section of the tube shape is rectangular, it may be another shape, for example, a circular shape or a polygonal shape having five or more sides. As long as the shape allows progressive failure to occur without causing buckling failure, the cross section may be partially cut out (for example, C-shaped), and the cross section is not limited to an endless shape.
[0016] In the case where the impact-absorbing member is tubular, the impact-absorbing member fractures and the fragments enter the tube. The fragments accumulated in the tube clog the tube, increasing the rigidity, which inhibits compressive deformation of the impact-absorbing member in this region. In other words, the region where the fragments enter the tube and inhibit the compressive deformation does not contribute to the progressive failure. Therefore, the one portion where the impact-absorbing member is fixed to the face plates is preferably provided in a region where the fragments enter the inside and inhibit the compressive deformation when failure occurs (a region not contributing to the progressive failure).
[0017] In the above-described impact-absorbing structure, the impact-absorbing member is formed of a composite material consisting of a resin and reinforcing fibers.
[0018] By using a composite material consisting of a resin and reinforcing fibers as the impact-absorbing member, the weight can be reduced.
[0019] Preferably, carbon-fiber reinforced plastic (CFRP) is used as the composite material.
[0020] A thermosetting resin such as epoxy resin, unsaturated polyester resin, phenolic resin, polyimide resin, or polyurethane resin; or a thermoplastic resin such as polyamide, polyethylene terephthalate, polyester, or polycarbonate is used as the resin constituting the composite material, according to the necessity.
[0021] Preferably, carbon fibers are used as the reinforcing fibers constituting the composite material. Besides carbon fibers, glass fibers, aromatic polyamide fibers (aramid fibers), alumina fibers, silicon carbide fibers, boron fibers, or the like may be used.
[0022] In the above-described impact-absorbing structure, a release agent that prevents the impact-absorbing member from being bonded to the face plates is provided between the remaining portion of the impact-absorbing member and the face plates.
[0023] By using the release agent that prevents the impact-absorbing member from being bonded to the face plates, relative movement between the impact-absorbing member and the face plates can be easily achieved.
[0024] For example, an FEP (tetrafluoroethylene-hexafluoropropylene copolymer (4.6fluoride)) film may be used as the release agents.
[0025] The release agent is preferably provided between the impact-absorbing member and the core member to further ensure the relative movement.
[0026] In the above-described impact-absorbing structure, one of the pair of face plates is provided so as to expose one end of the remaining portion of the impact-absorbing member.
[0027] By providing one of the pair of face plates so as to expose one end of the remaining portion of the impact-absorbing member in order not to close the space where the impact-absorbing member is disposed, the face plates are prevented from inhibiting the progressive failure of the impact-absorbing member.
[0028] A method for producing a impact-absorbing structure according to an aspect of the present invention, the structure including a pair of flat, plate-like face plates arranged to oppose each other with a predetermined distance therebetween; a core member arranged between the face plates and fixed to the face plates; and a impact-absorbing member arranged between the face plates, at the core member side, the impact-absorbing member extending in one direction and fracturing progressively due to an impact compression force acting in the one direction, includes fixing one portion of the impact-absorbing member to the face plates with an adhesive; and arranging a release agent, which prevents the impact-absorbing member from being bonded to the face plates, between a remaining portion of the impact-absorbing member and the face plates.
[0029] Because the adhesive is used at one portion of the impact-absorbing member and the release agent is used at the remaining portion of the impact-absorbing member, it is possible to easily produce the impact-absorbing member with one portion fixed to the face plates and the remaining portion capable of movement relative to the face plates.
[0030] In the above-described impact-absorbing structure, because the remaining portion of the impact-absorbing member is capable of movement relative to the face plates, the progressive failure of the impact-absorbing member propagates without being impeded by the face plates. Thus, progressive failure with a large displacement occurs, whereby the impact energy can be effectively absorbed.
[0031] In the method for producing an impact-absorbing structure of the present invention, the adhesive is used at the one portion of the impact-absorbing member and the release agent is used at the remaining portion of the impact-absorbing member. Thus, it is possible to easily produce the impact-absorbing member with one portion fixed to the face plates and the remaining portion capable of movement relative to the face plates.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0032] FIG. 1 is a perspective view showing an underfloor structure of a helicopter according to an embodiment of the present invention.
[0033] FIG. 2 is a partial sectional perspective view of a impact-absorbing structure according to an embodiment of the present invention.
[0034] FIG. 3 is a longitudinal sectional view showing a relevant part at the upper end of the impact-absorbing structure in FIG. 2 .
[0035] FIG. 4 is a longitudinal sectional view showing a relevant part at the lower end of the impact-absorbing structure in FIG. 2 .
[0036] FIG. 5 is an exploded perspective view showing a method for producing a sandwich panel.
[0037] FIG. 6 is a graph showing an impact absorbing process at the time of application of an impact load.
[0038] FIG. 7 is a perspective view showing a conventional impact-absorbing structure.
DETAILED DESCRIPTION OF THE INVENTION
[0039] An embodiment of the present invention will be described below with reference to the drawings.
[0040] FIG. 1 shows a perspective view of an underfloor structure of a helicopter that employs an impact-absorbing structure of the present invention.
[0041] As shown in the figure, the underfloor structure is configured such that a plurality of frames 3 and a plurality of beams 5 are fixed to an underfloor outer board 1 that constitutes the bottom surface.
[0042] The frames 3 extending in the width direction are arranged in parallel at predetermined intervals. The beams 5 extending in the longitudinal direction, substantially perpendicular to the frames 3 , are arranged in parallel at predetermined intervals.
[0043] The frames 3 and the beams 5 constitute the impact-absorbing structure. More specifically, composite-material tubes (impact-absorbing members) 7 are provided so as to stand upright from the underfloor outer board 1 , at positions indicated by broken lines in the figure. The composite-material tubes 7 are provided at similar positions also on the other frames 3 and the beams 5 where no composite-material tubes 7 are illustrated. Note that the positions of the composite-material tubes 7 shown in the figure are merely examples, and the composite-material tubes 7 are provided at appropriate positions in the frames 3 and the beams 5 .
[0044] FIG. 2 shows a partial sectional perspective view of the frame 3 or the beam 5 in FIG. 1 , serving as the impact-absorbing structure.
[0045] As shown in the figure, an upright wall portion, which constitutes the main part of the frame 3 or the beam 5 , is a sandwich panel 9 . The lower end of the sandwich panel 9 is supported from one side by a T-shaped rail 11 having a T-shaped cross section and is fixed to the underfloor outer board 1 on the lower side. The upper end of the sandwich panel 9 is sandwiched from both sides between L-shaped rails 13 having an L-shaped cross section and is fixed to an upper structural member 15 on the upper side.
[0046] Instead of the T-shaped rail 11 for fixing the lower end of the sandwich panel 9 , an L-shaped rail having an L-shaped cross section may be used.
[0047] The sandwich panel 9 is configured such that planar core members 17 and the composite-material tubes 7 are arranged next to each other and are sandwiched from both sides between the face plates 19 so as to form a wall. That is, the composite-material tubes 7 are arranged between the adjoining core members 17 in the lateral direction perpendicular to the upright direction.
[0048] The face plates 19 are thin plates and mainly provide the strength of the sandwich panel 9 . Although various materials, including composite material, resin, and metal, may be used for the face plates 19 , carbon-fiber reinforced plastic (CFRP), for example, is preferably used.
[0049] From the standpoint of assuring strength and reducing weight, the core members 17 preferably have a honeycomb structure. Although various materials, including composite material, resin, and metal, may be used for the core members 17 , aromatic polyamide (aramid), for example, is preferably used.
[0050] The composite-material tubes 7 are arranged with the axes thereof extending in the upright direction of the sandwich panel 9 . In other words, they are arranged with the axes thereof extending in a direction of compression generated when an impact force is applied from the underfloor outer board 1 .
[0051] The composite-material tubes 7 are tubular with the axes thereof extending in a direction of compression generated by the impact force (one direction). Although the preferred cross section of the tube shape is rectangular, it may be another shape, for example, a circular shape or a polygonal shape having five or more sides.
[0052] The composite-material tubes 7 are formed of a composite material consisting of a resin and reinforcing fibers; a carbon-fiber reinforced plastic (CFRP) is preferably used.
[0053] A thermosetting resin such as epoxy resin, unsaturated polyester resin, phenolic resin, polyimide resin, or polyurethane resin; or a thermoplastic resin such as polyamide, polyethylene terephthalate, polyester, or polycarbonate is used as the resin constituting the composite material, according to the purpose.
[0054] Preferably, carbon fibers are used as the reinforcing fibers constituting the composite material. Besides carbon fibers, glass fibers, aromatic polyamide fibers (aramid fibers), alumina fibers, silicon carbide fibers, boron fibers, or the like may be used.
[0055] FIG. 3 shows a longitudinal sectional view of the upper end of the sandwich panel 9 and the vicinity thereof. The figure shows a longitudinal sectional view taken at the position of the composite-material tube 7 . As shown in the figure, a bonded region A where the upper end of the composite-material tube 7 is fixed to the face plates 19 by an adhesive 21 is formed in a region corresponding to one portion at the upper end of the composite-material tube 7 . Preferably, for example, an epoxy adhesive film is used as the adhesive 21 .
[0056] On the other hand, below the bonded region A (on the underfloor outer board side), i.e., in the region corresponding to the remaining portion of the composite-material tube 7 , a non-bonded region B where a release film (a release agent) 23 prevents the remaining portion of the composite-material tube 7 from being bonded to the face plates 19 is formed. As will be described below, the release film 23 also prevents the remaining portion of the composite-material tube 7 from being bonded to the adjacent core members 17 .
[0057] As has been described, the composite-material tubes 7 are attached to the face plates 19 and the core members 17 only at one portion at the upper ends, and the other remaining portions are not bonded to the face plates 19 or the core members 17 so as to be capable of relative movement.
[0058] A material that can prevent the composite-material tubes 7 from being bonded to the face plates 19 and the core members 17 by an adhesive is used as the release film 23 ; for example, an FEP (tetrafluoroethylene-hexafluoropropylene copolymer (4.6 fluoride)) film is preferably used. The FEP film is available from RICHMOND CORPORATION, under the trade name A5000 WHITE.
[0059] The bonded region A can be defined as follows.
[0060] Because the composite-material tube 7 is tubular, the fragments enter an inside 7 c of the tube when the composite material is fractured. The fragments accumulated in the inside 7 c of the tube clog the tube, increasing the rigidity, which inhibits compressive deformation in this region. In other words, the region where the fragments enter the inside 7 c of the tube and inhibit the compressive deformation does not contribute to the progressive failure. Therefore, the bonded region A is preferably provided in a region where the fragments enter the inside 7 c of the tube and inhibit the compressive deformation when failure occurs (a region not contributing to the progressive failure). This can increase the displacement during the progressive failure as much as possible.
[0061] FIG. 4 shows a longitudinal sectional view of the lower end of the sandwich panel 9 and the vicinity thereof.
[0062] As shown in the figure, the lower end of the composite-material tube 7 is separated from the underfloor outer board 1 and the T-shaped rail. The sandwich panel 9 is connected to the T-shaped rail 11 at a fixing position 33 , only through one face plate 19 a with fixing means such as a bolt.
[0063] Another face plate 19 b is shorter at the lower end than the one face plate 19 a . Therefore, a part of the lower end of the composite-material tube 7 is exposed without being covered by the other face plate 19 b . In this manner, by not covering the lower end of the composite-material tube 7 with the other face plate 19 b in order not to close the space where the composite-material tube 7 is disposed, the face plates are prevented from inhibiting the progressive failure of the composite-material tubes 7 .
[0064] Next, using FIG. 5 , a method for producing the sandwich panel 9 will be described.
[0065] First, a plurality of core members 17 are arranged on a face plate 19 L positioned on the lower side. Adhesive films 25 having shapes corresponding to the core members 17 are inserted between the face plate 19 L and the core members 17 .
[0066] The release film 23 is wound around the composite-material tube 7 so as to cover the outer periphery thereof, and the release film 23 is fixed by a tape (for example, a PTFE tape) 26 . The release film 23 is disposed from one end 7 a of the composite-material tube 7 to an intermediate position that is forward of the other end 7 b . The region where the release film 23 is provided constitutes the non-bonded region B. Accordingly, the region of the portion at the other end 7 b , where the release film 23 is not provided, constitutes the bonded region A.
[0067] The composite-material tube 7 , around which the release film 23 is wound as described above, is arranged adjacent to the core members 17 and the adhesive films 25 . At this time, an adhesive film 27 is disposed between the face plate 19 L and the lower surface of the bonded region A of the composite-material tube 7 . Between each of the side surfaces of the bonded region A of the composite-material tube 7 and the core member 17 , an adhesive film 29 and a foam adhesive 31 are arranged in sequence from the composite-material tube 7 side. An epoxy foam adhesive is preferably used as the foam adhesive 31 .
[0068] Then, adhesive films 34 having shapes corresponding to the core members 17 are disposed on the top surfaces of the core members 17 , an adhesive film 35 is disposed on the top surface of the bonded region A of the composite-material tube 7 , and then, a face plate 19 U is placed thereon from above.
[0069] These members arranged as described above are heated and pressed into a single member to form the sandwich panel 9 .
[0070] As shown in FIG. 2 , the sandwich panel 9 is fixed at the bottom to the underfloor outer board 1 through the T-shaped rail 11 and is fixed at the top to the upper structural member 15 through the two L-shaped rails 13 .
[0071] Next, using FIG. 6 , an impact absorbing process of application of an impact load will be described. In the figure, the horizontal axis indicates the displacement, and, more specifically, it indicates the compressive displacement of the composite-material tubes 7 in the axial direction. The vertical axis indicates the load applied to the impact-absorbing structure.
[0072] As shown in the figure, when an impact load is applied, the load rises sharply (see point P 1 ). Then, the non-bonded region B of the composite-material tube 7 fractures progressively from the end at the underfloor outer board, gradually increasing the displacement while being subjected to a predetermined load. The increasing displacement while being subjected to a predetermined load continues until the progressive failure propagates across the entire region of the non-bonded region B of the composite-material tube. Because the amount of impact energy absorbed is proportional to the area S in the figure, the larger the displacement caused by the progressive failure, the larger the amount of energy absorbed. In the composite-material tube 7 according to this embodiment, because the displacement during the progressive failure is increased by the non-bonded region B, a large amount of energy can be absorbed.
[0073] In contrast, as in the case of the related art, if the entire region of the composite-material tube is bonded to the face plates without providing a non-bonded region, the face plates restrain the composite-material tube, preventing the progressive failure from propagating effectively. This phenomenon is indicated by the broken line in the figure. That is, when an impact load is applied, the impact load rises significantly (see point P 2 ) because the progressive failure does not immediately propagate. Then, the progressive failure does not effectively propagate because the composite-material tube is restrained by the face plates. This causes buckling failure subsequent to the failure of the face plates and results in total failure. Thus, almost no load is supported. As has been described, with the composite-material tube with the entire region fixed to the face plates without providing a non-bonded region, only a small area can be obtained in the figure. Thus, it is impossible to absorb a large impact energy.
[0074] This embodiment provides the following advantages.
[0075] One portion (bonded region A) of the composite-material tube 7 is fixed to the face plates 19 , and the remaining portion (non-bonded region B) can be moved relative to the face plates 19 . This allows the progressive failure of the composite-material tube 7 to propagate without being impeded by the face plates 19 . Thus, because the composite-material tube 7 can assuredly fracture progressively at the remaining portion capable of relative movement, progressive failure with a large displacement occurs. Thus, the impact energy is effectively absorbed.
[0076] Furthermore, because the composite-material tube 7 is tubular, the progressive failure can be allowed to appropriately propagate without causing buckling failure.
[0077] Furthermore, because the adhesive films 27 , 29 , and 35 are used in one portion (bonded region A) of the composite-material tube 7 , and the release film 23 is used in the remaining portion (non-bonded region B) of the impact-absorbing member, it is easy to produce a structure in which the one portion is fixed to the face plates 19 and the remaining portion is capable of movement relative to the face plates 19 .
[0078] Although an application of the impact-absorbing structure to the underfloor structure of a helicopter has been described in this embodiment, the present invention is not limited thereto, and it can be applied to, for example, fixed wing aircraft and cars.
[0079] Although the release film 23 is used as the release material in this embodiment, the present invention is not limited thereto. As long as the composite-material tube 7 is prevented from being bonded or joined to the adjacent members (the face plates 19 and the core members 17 ), application of a release lubricant is also possible.
[0080] Although the preferred cross section of the composite-material tube 7 is rectangular as in this embodiment, it may be another shape, for example, a circular shape or a polygonal shape having five or more sides. In addition, as long as the shape allows progressive failure to occur without causing buckling, the cross section may be partially cut out (for example, C-shaped), and the cross section is not limited to an endless shape. | An object is to provide an impact-absorbing structure superior in impact-absorbing capacity. An impact-absorbing structure includes a pair of flat, plate-like face plates arranged to oppose each other with a predetermined distance therebetween; a core member arranged between the face plates and fixed to the face plates; and a composite-material tube arranged between the face plates, at the core member side, the impact-absorbing member extending in one direction and fracturing progressively due to an impact compression force acting in the one direction. The composite-material tube is fixed to the face plates at one portion constituting a bonded region and is allowed to move relative to the face plates at a remaining portion constituting a non-bonded region B. | 8 |
[0001] This application claims priority from Korean Patent Application No.2003-48426, filed on Jul. 15, 2003, the contents of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an MB810 encoder and/or decoder, a dual mode encoder and/or decoder, and an MB810 code generation method, and more particularly, to an MB810 encoder and/or decoder, a dual mode encoder and/or decoder, and an MB810 code generation method using control codes satisfying conditions of a DC-free code and spectrum 0 at Nyquist frequency.
[0004] 2. Description of the Related Art
[0005] When data is to be encoded into codes and transmitted, it should be first guaranteed due to the characteristic of transmission lines that the condition of a DC-free code is satisfied. A lot of research projects have been focused on generation methods of this DC-free code. Also, it has been known that in order to transmit data at a high speed, a smaller transmission bandwidth that is required to encoded codes is more advantageous than a larger bandwidth and theoretically the minimum bandwidth desired to be transmitted should have spectral null at the Nyquist frequency.
[0006] In an article, “A condition for stable minimum-bandwidth line codes”, published in IEEE Trans. on Comm., Vol. COM-33, No. 2, pp152-157, February 1985, the rationale of the condition that in addition to the DC-free condition, the spectrum should also be 0 at the Nyquist frequency is theoretically analyzed. Also, in an article, “DC-free and Nyquist-free error correcting convolutional codes”, published in Electronics Letters, Vol. 32, No. 24, pp 2196-2198, November, 1996, a (4, 3) code satisfying the conditions described above is suggested.
[0007] Meanwhile, U.S. Pat. No. 4,486,739 discloses a method in which a 5B/6B coder and a 3B/4B coder are combined to generate an 8B/10B coder to limit a run length, and based on 8-bit data, 10-bit code and control codes (align, skip, comma, etc.) required for transmission of the generated code are generated. However, though the codes generated by this method are DC-free codes, those are not minimum bandwidth codes.
[0008] U.S. Pat. No. 5,663,724 discloses a method in which by a 16B/20B encoder implemented by placing two 8B/10B encoders in parallel in order to apply the method of U.S. Pat. No. 4,486,739 to fiber channels, an upper 3B/4B encoder controls the disparity of a lower 5B/6B encoder and a lower 3B/4B encoder controls the disparity of an upper 5B/6B encoder of the next word. However, since the encoder suggested in the U.S. Pat. No. 5,663,724 is also an 8B/10B encoder in essence, the codes generated by the encoder are DC-free codes but not minimum bandwidth codes.
[0009] Also, U.S. Pat. No. 6,501,396 discloses a method in which in order to solve the shortcoming of the U.S. Pat. No. 5,663,724 that the number of encoders connected in parallel is limited to 2, a block to control disparity is separately implemented to control disparity in each channel. Though this method solves the problem of the limited number of channels capable of transmitting data in parallel, the codes generated by the encoder are also DC-free codes but not minimum bandwidth codes.
[0010] U.S. Pat. No. 6,425,107 discloses a method in which in order to more simply implement an encoder in encoding 8 bits into 10 bits, all possible balanced (equal number of logic 0 and logic 1 bits) 10-bit codes are selected to obtain 256 entries, and if there are less than 256 entries, imbalanced 10-bit codes which are imbalanced by 2 bits or less are used. However, the codes generated by this method are also DC-free but not minimum bandwidth codes.
[0011] Also, U.S. Pat. No. 6,441,756 discloses an 8B/14B code formed with a control code group separate from a data conversion code group in order to increase the probability of DC suppression. However, the codes suggested here are also DC-free codes but not minimum bandwidth codes.
[0012] Meanwhile, U.S. Pat. No. 6,362,757 discloses MB810 line code generation method and structure. The method disclosed by the U.S. Pat. No. 6,362,757 can generate minimum bandwidth codes capable of generating spectral null even at the Nyquist frequency, as well as DC-free codes, but has some problems when practically applied. First, there is a code whose run length (that is, the number of contiguous 0's or 1's) is 7 in the code itself. Also, there is a danger that run length exceeds 7 due to neighboring codes when 10-bit codes are transmitted. At this time, the worst case that the run length is 9 may occur. Accordingly, in the MB810 line code generation method and structure disclosed in the U.S. Pat. No. 6,362,757, it is difficult to utilize the clock extraction circuit used in the conventional 8B/10B codes. Also, since a code (comma code) for distinguishing frames used in the conventional 8B/10B encoder is included in a data code and there is no specific mention on the code (comma code) for distinguishing frames, it is difficult to use this method in a dual mode operation in which an 8B/10B encoder and an MB810 encoder are embedded and a user selects one encoder.
[0013] Also, Korean Patent Laying-Open No. 2003-0020519 discloses a method to enable dual mode use of the conventional 8B/10B coder and MB810 coder in order to complement the method of U.S. Pat. No. 6,362,757. This method uses codes /A/, /K/, /R/, as IDLE code group, in order to determine whether a received code is an 8B/10B code or an MB810 code. However, in order to use this method, the structures of 8B/10B encoders and decoders widely used at present should be changed.
SUMMARY OF THE INVENTION
[0014] The present invention provides an MB810 encoder and/or decoder capable of utilizing a clock extraction circuit used in the prior art 8B/10B code method by reducing a run length to 6 or less, a dual mode encoder and/or decoder capable of selectively using MB810 encoder and/or decoder without changing the structure of the prior art 8B/10B encoder and/or decoder, and an MB810 code generation method having a reduced transmission bandwidth compared to the prior art 8B/10B codes.
[0015] According to an aspect of the present invention, there is provided an MB810 code generation method comprising: forming 12 state points in the form of a 4×3 matrix on a state transition map formed with binary unit digital sum variation & alternate sum variation (BUDA) to generate a 10-bit code from 8-bit data; outputting a 10-bit code from a predetermined state point forming the matrix; selecting codes forming a complementary pair from a set of codes capable of arriving at state points forming the matrix; selecting codes forming the 12 state points by supplementing state points lacked in the codes forming a complementary pair; selecting control codes including IDLE code from the codes forming the 12 state points; and removing codes generating the IDLE code by a bit string between neighboring codes among the codes forming the 12 state points.
[0016] According to another aspect of the present invention, there is provided an MB810 encoder comprising: a table storage unit which stores code tables having data codes written therein, the data codes generated by forming 12 state points in the form of a 4×3 matrix on a state transition map formed with binary unit digital sum variation & alternate sum variation (BUDA) to generate a 10-bit code from 8-bit data, and outputting a 10-bit code from a predetermined state point forming the matrix, and then, supplementing second codes having state points lacked in first codes forming complementary pairs selected from a set of 10-bit codes capable of arriving at state points forming the matrix, and then, selecting control codes including IDLE code among the first and second codes, and removing codes generating the IDLE code by a bit string between neighboring codes among the second codes, and codes that are selected as the control codes; a first buffer unit which stores an 8-bit control code input from the outside; a second buffer unit which stores an 8-bit control code input from the outside; and a state transition unit which, based on a current state and the contents of the 8-bit data code input from the first buffer unit, reads out a 10-bit data code from a code table stored in the table storage unit and outputs the code, and, based on a current state and the contents of the 8-bit control code input from the second buffer unit, reads out a 10-bit control code from a code table stored in the table storage unit, and based on predetermined state transition information, is transited to one of 12 state points on the state transition map.
[0017] According to still another aspect of the present invention, there is provided an MB810 decoder comprising: a table storage unit which stores code tables having data codes written therein, the data codes generated by forming 12 state points in the form of a 4×3 matrix on a state transition map formed with binary unit digital sum variation & alternate sum variation (BUDA) to generate a 10-bit code from 8-bit data, and outputting a 10-bit code from a predetermined state point forming the matrix, and then, supplementing second codes having state points lacked in first codes forming complementary pairs selected from a set of 10-bit codes capable of arriving at state points forming the matrix, and then, selecting control codes including IDLE code among the first and second codes, and removing codes generating the IDLE code by a bit string between neighboring codes among the second codes, and codes that are selected as the control codes; a decoding unit which based on the contents of a 10-bit code input from the outside, reads out an 8-bit data code or an 8-bit control code from a code table stored in the table storage unit; a first buffer unit which stores the 8-bit data code input from the decoding unit and then outputs the code to the outside; and a second buffer unit which stores the 8-bit control code input from the decoding unit and then outputs the code to the outside.
[0018] According to yet still another aspect of the present invention, there is provided a dual mode encoder comprising: an MB810 encoder; an 8B/10B encoder; a determination unit which determines an encoder to be used as an operation encoder between the MB810 encoder and the 8B/10B encoder; a first selection unit which provides an 8-bit code input from the outside to the encoder determined as the operation encoder; a second selection unit which receives a 10-bit code corresponding to the 8-bit code from the encoder determined as the operation encoder, and outputs the code; a serial conversion unit which converts the 10-bit code input from the second selection unit into a 10-bit serial code; a code clock generation unit which receives a data clock from the outside, generates a code clock, and provides the clock signal to the serial conversion unit; a first low pass filter which when the MB810 encoder is determined as the operation encoder, removes a predetermined frequency bandwidth from a 10-bit serial code input from the serial conversion unit; a first amplifier which amplifies a 10-bit serial code input from the first low pass filter and outputs the code; a second low pass filter which when the 8B/10B encoder is determined as the operation encoder, removes a predetermined frequency bandwidth from a 10-bit serial code input from the serial conversion unit; a second amplifier which amplifies a 10-bit serial code input from the second low pass filter and outputs the code; and a switch unit which according to the encoder determined as the operation encoder, provides a 10-bit serial code output from the serial conversion unit selectively to the first and second low pass filters, and selectively outputs a 10-bit serial code output from the first and second amplifiers to the outside.
[0019] According to a further aspect of the present invention, there is provided a dual mode decoder comprising: an MB810 decoder; an 8B/10B decoder; a mode detection unit which detects a decoder to be used as an operation decoder between the MB810 decoder and the 8B/10B decoder; a first low pass filter which when the MB810 decoder is determined as the operation decoder, removes a predetermined frequency bandwidth from a 10-bit code input from the outside; a second low pass filter which when the 8B/10B decoder is determined as the operation decoder, removes a predetermined frequency bandwidth from a 10-bit code input from the outside; an IDLE code detection unit which detects IDLE code from the 10-bit code and transfers to the mode detection unit; a first switch unit which according to the decoder determined as the operation decoder, selectively outputs the 10-bit code input from the first low pass filter and the second low pass filter; a parallel conversion unit which converts the 10-bit code input from the first switch into a parallel code and outputs a 10-bit parallel code; a first selection unit which provides the 10-bit parallel code to the decoder determined as the operation decoder between the MB810 decoder and the 8B/10B decoder; and a second selection unit which selectively outputs an 8-bit code corresponding to the 10-bit parallel code input from the decoder determined as the operation decoder.
[0020] According to the apparatuses and method, the transmission bandwidth is reduced compared to the prior art 8B/10B codes such that long distance transmission is enabled, and without changing the prior art 8B/10B coding method, the codes are applied together with MB810 codes such that the dual mode operation can be performed in which a user can select a desired line code.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above objects and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[0022] FIG. 1 is a state transition map showing a binary unit digital sum variation & alternate sum variation (BUDA) stack for generating MB810 codes according to the present invention and 12 state points;
[0023] FIGS. 2 a through 2 f are diagrams of code tables in which codes used in an MB810 encoder according to the present invention are recorded;
[0024] FIG. 3 is a diagram of a code table in which codes that can be internally used in the MB810 according to the present invention are recorded;
[0025] FIGS. 4 a through 4 e are diagrams of code tables in which codes used in an MB810 decoder according to the present invention are recorded;
[0026] FIGS. 5 through 7 are diagrams of tables in which state transition information related to operations of MB810 encoder when encoding 8-bit data information according to the present invention is recorded;
[0027] FIGS. 8 through 10 are diagrams of tables in which state transition information related to operations of the MB810 encoder when encoding 8-bit control information according to the present invention is recorded;
[0028] FIG. 11 is a diagram showing the power spectrum of an 8B/10B line code;
[0029] FIG. 12 is a block diagram of the structure of an MB810 encoder according to the present invention constructed by using codes generated by an MB810 code generation method according to the present invention;
[0030] FIG. 13 is a block diagram of the structure of an MB810 decoder according to the present invention constructed by using codes generated by an MB810 code generation method according to the present invention;
[0031] FIG. 14 is a block diagram showing the structure of a dual mode encoder according to the present invention;
[0032] FIG. 15 is a block diagram showing the structure of a dual mode decoder according to the present invention; and
[0033] FIGS. 16 a and 16 b are flowcharts of the steps performed by a dual mode processing method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Hereinafter, the present invention will be described in detail by explaining preferred embodiments of an improved MB810 line code apparatus including control codes and an MB810 code generation method according to the present invention with reference to the attached drawings.
[0035] Referring to FIG. 1 , s 0 , . . . , s 11 denote respective state points of an MB810 encoder and a group of state points are set in the form of a 4×3 matrix. Arrows shown in FIG. 1 indicate paths through which an MB810 encoder can change according to the output of a 10-bit code converted corresponding to data input to the encoder when the MB810 encoder is in each state point. If the sign of output bits is 0, the state moves to the left by one arrow, and if the sign of output bits is 1, the state moves to the right by one arrow. Since the number of output bits is 10, the state moves along 10 arrows according to the sign of the code. A method for selecting a code on this state transition map will now be explained.
[0036] First, after a 10-bit code is output from an arbitrary state point among s 0 , . . . , s 11 , only those codes that can reach any one state point of s 0 , . . . , s 11 are useful codes having minimum bandwidths and therefore those codes can be set as valid codes. The number of valid codes among 1024 codes is 890.
[0037] Next, in selecting IDLE code, in order to easily distinguish from 8B/10B codes when the encoder operates in dual mode, IEEE 802.3 standard K28.7 (0011111000 and 1100000111) which embeds a comma among those codes that are not used by 8B/10B codes is selected, and removed from candidate lists for data codes and control codes.
[0038] Then, codes whose run length exceeds 6 (for example, in the case of 1011011110, the run length is 4) are removed among the output codes. In case when the run length exceeds 6 by a neighboring code, the code having a longer run length is removed. That is, if the preceding code is 1011001111 and the succeeding code is 1110010111, 1011001111 is removed from the candidate list.
[0039] After combining all the remaining codes into complementary pairs, code combinations according to state transitions of these pairs are generated continuously three times. Then, among the generated code combinations, those code combinations that cause −K28.7 to occur immediately after +K28.7 or +K28.7 to occur immediately after −K28.7 are collected and code pairs providing such code combinations are removed from the candidate list.
[0040] Next, by using the characteristic that an encoder necessarily returns to a starting state point according to state transitions, complementary code pairs that make the highest number of complementary code pairs as possible are selected when these code pairs are selected.
[0041] Next, codes that can travel all state points only with one complementary code pair (that is, only with two codes) among the selected complementary code pairs are selected. All 161 pairs are selected as these codes.
[0042] Next, among the selected complementary code pairs, K28.0, K28.3, K28.4, K27.7 and K20.7 codes that are 8B/10B control codes defined in IEEE 802.3ae are selected as MB810 control codes with the same function as the control function of 8B/10B codes. Among the existing 8B/10B control codes, only with one code pair, K29.7 code is short of the number of states such that it is difficult to make a code combination having a minimum bandwidth when K29.7 code is used as a control code having the same function even in the MB810 code. Accordingly, another code pair capable of traveling lacked state points should be added or the code should be replaced by a code capable of traveling all state points only with one code pair. For simplification of control function operation, one code pair, 1100111000 and 001100011, is used as K29.7 of MB810 code.
[0043] Next, code combinations that can travel all state points with two pairs (that is, four codes) are selected. The number of combinations in which thus selected two pairs are assigned to data is 73 (that is, 73×4=292 codes).
[0044] Next, by combining 24 codes having only state points of s 0 , s 1 and s 2 with 24 codes having state points of s 3 , s 4 , s 5 , s 6 , s 7 , s 8 , s 9 , s 10 , and s 11 (that is, 9 state transition points) among the 161 pairs having state transitions selected above, 24 code pairs are selected.
[0045] Also, by combining 24 codes having only state points of s 9 , s 10 and s 11 with 24 codes having state points of s 0 , s 1 , s 2 , s 3 , s 4 , s 5 , s 6 , s 7 , and s 8 (that is, 9 state transition points) among the 161 pairs having state transitions selected above, 24 code pairs are selected.
[0046] Finally, among codes having 9 state points and not included in the 161 pairs selected above, complementary pairs whose run length is 4 and whose bit shapes are 1111XXXXXX and 0000XXXXXX (X is 0 or 1) are combined into two pairs each. That is, it is made to be possible to output a different code according to the shape of final bits of a code output immediately before. Thus selected two code pairs are two kinds and include 1111001000, 0000110111, 000011101 and 1111000100, and 1111000010, 000011111101, 0000111110, and 1111000001.
[0047] Since thus the number of selected code pairs is 260, 256 pairs are assigned to data and the remaining four pairs can be used for special purposes internally in the MB810 coder, such as state synchronization of physical coding sublayer (PCS: physical coding lower layer defined in IEEE 802.3 standard), transmission of state information from an encoder to a decoder during IDLE cycle, and transmission of state information from an encoder to a decoder before data frame start.
[0048] MB810 codes generated by the above method are shown in FIGS. 2 a through 3 e. Codes shown in FIGS. 2 a through 2 f are those codes that are used by an MB810 encoder and forming 7 groups. Codes shown in FIG. 3 are those codes that can be internally used in an MB810 encoder and state information that can be output for each data item is shown together. Codes shown in FIGS. 4 a through 4 e are those codes that are used by an MB810 decoder. Since the decoder does not need state information when decoding data, state information is not written in FIGS. 4 a through 4 e.
[0049] Meanwhile, FIGS. 5 through 10 are tables in which codes and/or state information related to encoding operations of an MB810 encoder are written.
[0050] First, IDLE codes (that is, +K28.7/−K28.7) shown in FIG. 8 are those code that are always transmitted when data is not transmitted. In FIG. 8 , s 0 , s 1 , . . . , s 11 indicate states of an MB810 encoder, and in spaces below s 0 , s 1 , . . . , s 11 columns, state information to which the encoder is transited after a corresponding code is transmitted is written. In case where state information is not written, a corresponding code is not transmitted and the code in the row of the space where state information is located is output. Accordingly, if the state when IDLE code is desired to be transmitted is s 0 , the MB810 encoder outputs 1100000111 (that is, +K28.7) and is transited to s 3 state. Also, if IDLE code is continuously transmitted, 0011111000 (that is, −K28.7) is output and the encoder is transited to s 0 state.
[0051] If the state when IDLE code is desired to be transmitted is s 7 , the MB810 encoder outputs 1100000111 (that is, +K28.7) and is transited to s 10 state. Also, if IDLE code is continuously transmitted, 0011111000 (that is, −K28.7) is output and the encoder is transited to s 7 state. The codes in the second table of FIG. 8 are those codes that are used when skip control information code is transmitted. The operation of the MB810 encoder is the same as when IDLE code is output. The codes in the third table of FIG. 8 are those codes that are used when align control information code is output. When the state of the MB810 encoder is s 3 , 1100001011 (that is, +K28.3) as shown in FIG. 8 is output and the encoder is transited to s 4 state. Also, when align control information code is continuously transmitted, 1100001011 (that is, +K28.3) is transmitted and the encoder is transited to s 5 state. When align control information code is continuously transmitted further, 0011110100 (that is, −K28.3) is output and the encoder is transited to s 4 state.
[0052] Codes written in the first table of FIG. 9 are fault control information codes, codes written in the second table are frame start information codes, codes written in the third table are frame end information codes, and codes written in the fourth table are error control information codes. When the codes shown in FIG. 9 are output, the MB810 encoder operates in the same manner as when IDLE code is output.
[0053] Next, state transition information related to operations of the MB810 encoder when encoding 8-bit data information is written in tables shown in FIGS. 5 through 7 .
[0054] In the first table shown in FIG. 5 , a method used to encode data items of data group 0 ˜ 57 shown in FIGS. 2 a and 2 b is shown. For example, when the MB810 encoder is in s 4 state, a code in group A_L row in the first table shown in FIG. 5 is output and the encoder is transited to s 1 state. If a data item of data group 0 ˜ 57 is continuously encoded, a code in group A_R row in the first table shown in FIG. 5 is output and the encoder is transited to s 4 state.
[0055] In the second table shown in FIG. 5 , a method used to encode data items of data group 58 ˜ 136 shown in FIGS. 2 b and 2 c is shown. For example, when the MB810 encoder is in s 3 state, a code in group A_L row of the second table shown in FIG. 5 is output and the encoder is transited to s 4 state. If a data item of data group 58 ˜ 136 is continuously encoded, a code in group A_L row of the second table of FIG. 5 is output and the encoder is transited to s 5 state. If a data item of data group 58 ˜ 136 is continuously encoded further, a code in group A_R row of the second table of FIG. 5 is output and the encoder is transited to s 4 state.
[0056] In the third table shown in FIG. 5 , a method used to encode data items of data group 137 ˜ 160 shown in FIGS. 2 c and 2 d is shown. For example, when the MB810 encoder is in s 3 state, a code in group A_L row of the third table shown in FIG. 5 is output and the encoder is transited to s 0 state. If a data item of data group 137 ˜ 160 is continuously encoded, a code in group A_R row of the third table shown in FIG. 5 is output and the encoder is transited to s 9 state. If a data item of data group 137 ˜ 160 is continuously encoded further, a code in group A_L row of the third table shown in FIG. 5 is output and the encoder is transited to s 6 state. If a data item of data group 137 ˜ 160 is continuously encoded still further, a code in group A_L row of the third table shown in FIG. 5 is output and the encoder is transited to s 3 state.
[0057] In the first table shown in FIG. 6 , a method used to encode data items of data group 161 ˜ 185 shown in FIG. 2 d is shown. For example, when the MB810 encoder is in s 10 state, a code in group A_L row of the first table shown in FIG. 6 is output and the encoder is transited to s 1 state. If a data item of data group 161 ˜ 185 is continuously encoded, a code in group A_R row of the first table shown in FIG. 6 is output and the encoder is transited to s 4 state. If a data item of data group 161 ˜ 185 is continuously encoded further, a code in group A_R row of the first table of FIG. 6 is output and the encoder is transited to s 7 state. If a data item of data group 161 ˜ 185 is continuously encoded still further, a code in group A_R row of the first table shown in FIG. 6 is output and the encoder is transited to s 10 state.
[0058] In the second and third tables shown in FIG. 6 , a method used to encode data items of data group 186 ˜ 215 shown in FIGS. 2 d and 2 e is shown. For example, when the MB810 encoder is in s 10 state, a code in group A_L row in the second table shown in FIG. 6 is output and the encoder is transited to s 5 state. If a data item of data group 186 ˜ 216 is continuously encoded, a code in group B_R row of the third table shown in FIG. 6 is output and the encoder is transited to s 0 state. If a data item of data group 186 ˜ 216 is continuously encoded further, a code in group B_L row of the third table shown in FIG. 6 is output and the encoder is transited to s 5 state. If a data item of data group 186 ˜ 216 is continuously encoded still further, a code in group B_R row of the third table shown in FIG. 6 is output and the encoder is transited to s 0 state.
[0059] In the first and second tables shown in FIG. 7 , a method used to encode data items of data group 216 ˜ 244 shown in FIG. 2 e is shown. For example, when the MB810 encoder is in s 1 state, a code in group A_L row in the first table shown in FIG. 7 is output and the encoder is transited to s 8 state. If a data items of data group 216 ˜ 244 is continuously encoded, a code in group B_R row of the second table shown in FIG. 7 is output and the encoder is transited to s 9 state. If a data items of data group 216 ˜ 244 is continuously encoded further, a code in group B_L row of the first table shown in FIG. 7 is output and the encoder is transited to s 8 state.
[0060] In the first and second tables shown in FIG. 7 , a method used to encode data items of data group 216 ˜ 244 shown in FIG. 2 e is shown. For example, when the MB810 encoder is in s 1 state, a code in group A_L row in the first table shown in FIG. 7 is output and the encoder is transited to s 8 state. If a data item of data group 216 ˜ 244 is continuously encoded, a code in group B_R row of the second table shown in FIG. 7 is output and the encoder is transited to s 9 state. If a data item of data group 216 ˜ 244 is continuously encoded further, a code in group B_L row of the first table shown in FIG. 7 is output and the encoder is transited to s 8 state.
[0061] In the third and fourth tables shown in FIG. 7 , a method used to encode data items of data group 245 ˜ 255 of the data group shown in FIGS. 2 e and 2 f is shown. For example, when the MB810 encoder is in s 0 state, a code in group B_L row in the fourth table shown in FIG. 7 is output and the encoder is transited to s 7 state. If a data item of data group 245 ˜ 255 is continuously encoded, a code in group A_L row of the third table shown in FIG. 7 is output and the encoder is transited to s 2 state. If a data item of data group 245 ˜ 255 is continuously encoded further, a code in group A_R row of the third table shown in FIG. 7 is output and the encoder is transited to s 7 state.
[0062] FIG. 10 shows a state transition method for surplus codes that can be used internally for special purposes such as transition state information transmission, PCS synchronization or error indication. The operation method of codes belonging to the first and second tables shown in FIG. 10 is the same as the operation method to encode data items of data group 245 ˜ 255 explained above referring to FIG. 7 .
[0063] Meanwhile, the operation method of codes belonging to the third and fourth tables shown in FIG. 10 is basically the same as the operation method of the codes belonging to the first table shown in FIG. 5 , but in selecting a code, a code beginning with a sign opposite that of the last bit of a code output immediately before is selected. For example, if the last bit output immediately before is 1 and the current state after finishing transmission of a corresponding code is s 3 , a code in group B_L row in the fourth table shown in FIG. 10 is output and the encoder is transited to s 0 state. If the last bit output immediately before is 0 and the current state after finishing transmission of a corresponding code is s 3 , a code in group A_L row in the fourth table shown in FIG. 10 is output and the encoder is transited to s 0 state.
[0064] By using the characteristics of the codes selected as described above, a code error can be easily detected similarly to the 8B/10B code. That is, all control codes except IDLE code and align control code (that is, K28.3) have five 1's among 10 bits, and disparity (the degree that the number of 1's is not the same as the number of 0's in a code) is 0, and if identical codes are continuously transmitted, codes are always output in an alternate method (that is, outputting a complementary code). In addition, though disparity of K28.3 is 2, if identical codes are continuously transmitted, codes are always output in an alternate method in all the remaining state except s 0 , s 3 , s 8 , and s 11 states. Also, when codes of an identical group are continuously transmitted, data group 0 ˜ 57 operate the same as IDLE code and disparity is 0. Data group 59 ˜ 136 operate in the same manner as K28.3 and disparity is the same as that of K28.3. Data group 137 ˜ 184 do not operate in an alternate method but disparity is 0. Data group 185 ˜ 255 are combinations of codes whose disparities are 2 and 4, but when codes of an identical group (data group 185 ˜ 255 and the first and second code groups shown in FIG. 10 are regarded as identical groups) are continuously output, states are transited always in the direction that disparity is reduced. Finally, though disparity of data group 245 ˜ 255 and the first and second code groups shown in FIG. 10 is 2, when identical codes are continuously transmitted, codes are always output in an alternate method in all the remaining states except s 0 , s 3 , s 8 , and s 11 states. That is, except codes whose disparity is 0, those codes that continuously cause identical disparities are not transmitted twice or more. Accordingly, by using these characteristic, if an increasing or decreasing direction of disparity occurs twice or more, it is possible to determine an error.
[0065] When the power spectra of MB810 line code generated by the method described above and the power spectra of the prior art 8B/10B line code are calculated according to a method disclosed in an article “Spectra of Block Coded Digital Signals” (IEEE Trans. on Comm., Vol., COM-22, No. 10, pp1555-1564, October, 1974), the power spectra of 8B/10B line code are DC-free, while the power spectra of MB810 line code are not only DC-free but also spectral null in the Nyquist frequency (that is, a normalized frequency=0.5) as shown in FIG. 11 .
[0066] FIG. 12 is a block diagram of the structure of an MB810 encoder according to the present invention constructed by using codes selected by the method described above.
[0067] Referring to FIG. 12 , the MB810 encoder according to the present invention comprises a control data buffer 310 , an 8-bit data buffer 320 , a state transition unit 330 , and a code table storage unit 340 . The code table storage unit 340 comprises table A_L block 341 , table A_R block 342 , table B_L block 343 , table B_R block 344 , a comma code block 345 , and a control code block 346 and these blocks can be combined and implemented as one block. Table A_L block 341 , table A_R block 342 , table B_L block 343 , table B_R block 344 are for data codes and the comma code block 345 and control code block 346 are for control codes. A selection signal is a signal provided from the outside and indicates whether or not the MB810 encoder 300 is used.
[0068] Even though the internal state of the state transition unit 330 is an arbitrary state in an initial state of the MB810 encoder, it does not affect the operation of the MB810 encoder. However, for convenience, the internal state of the state transition unit 330 may be set to 0 when the encoder is initialized.
[0069] Input data is 8-bit data and is input from the outside in parallel. Control data is an 8-bit signal for controlling the operational state of the MB810 encoder and is input from the outside in parallel. Examples of control data are shown in FIG. 3 and FIGS. 8 through 10 and control data includes IDLE signal, align control information, and so on.
[0070] Control data input from the outside is stored in the control data buffer 310 and the control data buffer 310 outputs the stored control data to the state transition unit 330 . Meanwhile, the input data input from the outside is stored in the 8-bit data buffer 320 and the 8-bit data buffer 320 outputs the stored input data to the state transition unit 330 .
[0071] At this time, a case where the input data and control data are input at the same does not take place. That is, when the input data is input, the control data is not input, and when the control data is input, the input data is not input.
[0072] Accordingly, if the input data is input from the 8-bit data buffer 320 , the state transition unit 330 reads out a code recorded in table A_L block 341 , table A_R block 342 , table B_L block 343 , and table B_R block 344 according to the its own state information and the content of the input data, and outputs a 10-bit parallel code as an output code. Then, the state is transited as described above referring to FIGS. 5 through 7 .
[0073] Also, if the control data is input from the control data buffer 310 , the state transition unit 330 reads out a code recorded in the comma code block 345 and control code block 346 as shown in FIGS. 8 through 10 according to its own state information and the content of the control data, and outputs a 10-bit parallel code as an output code. Then, the state is transited as described above referring to FIGS. 8 through 10 .
[0074] FIG. 13 is a block diagram of the structure of MB810 decoder according to the present invention.
[0075] Referring to FIG. 13 , the MB810 decoder 400 according to the present invention comprises a control data buffer 410 , an 8-bit data buffer 420 , a state processing unit 430 , a code table storage unit 440 , and a code decoding unit 450 . The code table storage unit 440 comprises table A_L block 441 , table A_R block 442 , table B_L block 443 , table B_R block 444 , a comma code block 445 , and a control code block 446 , and these blocks may be combined and implemented as one block. Table A_L block 441 , table A_R block 442 , table B_L block 443 , table B_R block 444 are for data codes and the comma code block 445 and control code block 446 are for control codes. A selection signal is a signal provided from the outside and indicates whether or not the MB810 decoder 400 is used. Data clock is a clock signal provided from the outside to operate the MB810 decoder 400 .
[0076] If a 10-bit input code input from the outside in parallel is a data code, the code decoding unit 450 converts the input data code into 8-bit data information, referring to code tables stored in table A_L block 441 , table A_R block 442 , table B_L block 443 , table B_R block 444 , and transfers the converted 8-bit data to the 8-bit data buffer 420 . FIGS. 3 a through 3 e show code tables stored in table A_L block 441 , table A_R block 442 , table B_L block 443 , table B_R block 444 . The 8-bit data buffer 420 outputs in parallel the 8-bit data input from the code decoding unit 450 .
[0077] Also, if the 10-bit input code input in parallel from the outside is a control code, the code decoding unit 450 converts the input control code into an 8-bit control code, referring to code tables stored in the comma code block 445 and control code block 446 , and transfers the converted 8-bit control code to the control data buffer 410 . Code tables stored in the comma code block 445 and control code block 446 are shown in FIGS. 8 through 10 . The control data buffer 410 outputs in parallel the 8-bit control code input from the code decoding unit 450 .
[0078] Meanwhile, the code decoding unit 450 transfers two types of information to the state processing unit 430 . First, error determination information by the error detection unit 451 placed inside the code decoding unit 450 is transferred to the state processing unit 430 . Also, when a 10-bit code is input in parallel from the outside, if the input code is a code internally defined in the MB810 encoder/decoder, the code decoding unit 450 converts the input 10-bit code into 8-bit data information, referring to the ode table recorded in the control code block 446 , and transfers the converted 8-bit data information to the state processing unit 430 . The code table stored in the control code block 446 is shown in FIG. 3 .
[0079] The error detection unit 451 is an element placed inside the code decoding unit 450 checks whether or not the input 10-bit code is a code existing in the code table storage unit 440 , checks disparity of the input 10-bit code according to the method described above, counts the frequency of the increasing or decreasing directions of disparity, and if the increases or decreases are twice or more, determines that an error occurred in the input 10-bit code. That is, a code whose disparity is 0 does not cause a change to the previous disparity state, but if the previous disparity state is +1 (that is, a code in which the number of 1's is less than the number of 0's is once received) and the disparity of the currently input code is also +, the internal counter of the error detection unit 451 becomes +2. Meanwhile, if the previous disparity state is +1 and the disparity of the currently input code is −, the internal counter of the error detection unit 451 becomes 0. When the internal counter of the error detection unit 451 is +2, if the disparity of the currently input code is also +, the internal counter of the error detection unit becomes +3 such that the error detection unit 451 determines that an error occurred in the received code.
[0080] Based on the error determination result input from the code decoding unit 450 , the state processing unit 430 outputs 8-bit diagnosis data in parallel. In addition, based on the 8-bit data code input from the code decoding unit 450 , the state processing unit 430 outputs 8-bit diagnosis data in parallel. Since the codes internally defined by this MB810 encoder/decoder are not essential in the operation of the MB810 encoder/decoder, those codes can be used selectively.
[0081] FIG. 14 is a block diagram showing the structure of a dual mode encoder according to the present invention.
[0082] Referring to FIG. 14 , the dual mode encoder according to the present invention comprises a determination unit 510 , a first selection unit 520 , a clock generation unit 530 , an MB810 encoder 540 , an 8B/10B encoder 550 , a second selection unit 560 , a serial conversion unit 570 , a switch unit 575 , a first low pass filter 580 , a first amplifier 585 , a second low pass filter 590 , and a second amplifier 595 . The clock generation unit 530 , the 8B/10B encoder 540 , the serial conversion unit 570 , the first low pass filter 580 , and the first amplifier 585 are elements forming the prior art 8B/10B encoder.
[0083] The determination unit 510 determines whether the dual mode encoder according to the present invention is to be used in MB810 encoder mode or 8B/10B encoder mode. The determination unit provides mode selection information to the first selection unit 520 , the MB810 encoder 540 , the 8B/10B encoder 550 , the second selection unit 560 , and the switch unit 575 . By input a mode selection command, a user can control the determination content of the determination unit 510 .
[0084] If a data clock is provided, the clock generation unit 510 generates a code clock for a 10-bit code, and provides to the serial conversion unit 570 .
[0085] Based on mode selection information provided by the determination unit 520 , the first selection unit 520 transfers 8-bit input data and control data input in parallel from the outside, to one of the MB810 encoder 540 and the 8B/10B encoder 550 .
[0086] The MB810 encoder 540 has the same structure as that of the MB810 encoder 300 explained referring to FIG. 12 . If mode selection information indicating that the MB810 encoder is determined as the operating encoder is input from the determination unit 510 , the MB810 encoder 540 performs encoding based on the encoding method of the MB810 encoder 300 explained referring to FIG. 12 , and provides the generated 10-bit code to the second selection unit 560 .
[0087] If mode selection information indicating that the 8B/10B encoder is determined as the operating encoder is input from the determination unit 510 , the 8B/10B encoder 550 performs encoding based on the 8B/10B encoding method, and provides the generated 10-bit code to the second selection unit 560 .
[0088] The second selection unit 560 provides the 10-bit parallel code provided by the encoder determined as the operating encoder by the determination unit 510 (that is, any one of the MB810 encoder 540 and the 8B/10B encoder 550 ), to the serial conversion unit 570 . The serial conversion unit 570 converts the input 10-bit parallel code into a 10-bit serial code and provides to the switch unit 575 .
[0089] The switch unit 575 drives switch A so that the output signal of the serial conversion unit 570 is transferred to a low pass filter 580 or 590 corresponding to the encoder selected as the operating encoder by the determination unit 510 and drives switch B so as to selectively output the output signal of an amplifier 585 or 595 .
[0090] The first low pass filter 580 and the first amplifier 585 are elements corresponding to the MB810 encoder 540 and the second low pass filter 590 and the second amplifier 595 are elements corresponding to the 8B/10B encoder 550 .
[0091] The first low pass filter 580 in combination with a first low pass filter 605 shown in FIG. 15 has a cut-off frequency which becomes an optimum filter, and the roll off characteristic at the cut-off frequency is the same as that of the second low pass filter 590 . At this time, the roll off characteristic at the cut-off frequency means the attenuation amount for each frequency level compared to a reference frequency and group delay distortion.
[0092] The cut-off frequency that becomes an optimum filter by combination of the first low pass filter 580 and the first low pass filter 605 shown in FIG. 15 is half the cut-off frequency by combination of the second low pass filter 590 and a second low pass filter 610 corresponding to the 8B/10B decoder 660 shown in FIG. 15 .
[0093] The fist low pass filter 580 cuts off the high frequency band of the 10-bit serial code input through switch A of the switch unit 575 according to a designed cut-off frequency and roll off characteristic, and transfers the code to the first amplifier 585 . The first amplifier 585 amplifies the signal input from the first low pass filter 580 to suit an output power level determined by IEEE 802.3 standard specifications, and outputs the signal as a 10-bit output code through switch B of the switch unit 575 .
[0094] The second low pass filter 590 cuts off the high frequency band of the 10-bit serial code input through switch A of the switch unit 575 according to a cut-off frequency designed complying with IEEE 802.3 standard specifications and roll off characteristic, and transfers the code to the second amplifier 595 . The second amplifier 595 amplifies the signal input from the second low pass filter 590 to suit an output power level determined by IEEE 802.3 standard specifications, and outputs the signal as a 10-bit output code through switch B of the switch unit 575 .
[0095] FIG. 15 is a block diagram showing the structure of a dual mode decoder according to the present invention.
[0096] Referring to FIG. 15 , the dual mode decoder comprises a first low pass filter 605 , a second low pass filter 610 , a first switch unit 615 , a second switch unit 620 , a frequency multiplying unit 625 , a clock reproduction unit 630 , an IDLE code detection unit 635 , a mode detection unit 640 , a parallel conversion unit 645 , a first selection unit 650 , an MB810 decoder 655 , an 8B/10B decoder 660 , a data clock generation unit 665 , and a second selection unit 670 . Among these elements, the second switch unit 620 and the frequency multiplying unit 625 are selected employed, and when there is a user request, mode selection information detected in the mode detection unit 640 is transferred to the second switch unit 620 .
[0097] The first low pass filter 605 is a filter corresponding to the MB810 decoder 655 . The first low pass filter 605 cuts off the high frequency band of an input 10-bit serial code according to a designed cut-off frequency and roll off characteristic, and transfers the code to the first switch unit 615 . The second low pass filter 610 is a filter corresponding to the 8B/10B decoder 660 . The second low pass filter 610 cuts off the high frequency band of the input 10-bit serial code according to a designed cut-off frequency and roll off characteristic, and transfers the code to the first switch unit 615 . The first low pass filter 605 has a cut-off frequency which becomes an optimum filter by combination with the first low pass filter 580 shown in FIG. 14 , and the roll off characteristic at the cut-off frequency is the same as that of the second low pass filter 610 . The cut-off frequency which becomes an optimum filter by combination of the first low pass filter 605 and the first low pass filter 580 shown in FIG. 14 is half the cut-off frequency by combination of the second low pass filter 610 and the second low pass filter 590 corresponding to the 8B/10B encoder 550 shown in FIG. 14 .
[0098] In its initial state, the first switch unit 615 selects the output of the second low pass filter 610 , and when there is a request of the mode detection unit 640 , selects the first low pass filter 605 . The first switch unit 615 transfers the output of the selected low pass filter 605 or 610 , to the second switch unit 620 , the frequency multiplying unit 625 , the IDLE code detection unit 635 , and the parallel conversion unit 645 .
[0099] The frequency multiplying unit 625 multiplies the frequency of the 10-bit serial code provided through the first switch unit 615 by 2, and outputs the result to the second switch unit 620 . When there is no request from the mode detection unit 640 , the second switch unit 620 selects the output of the first switch unit 615 , and when there is a request from the mode detection unit 640 , selects the output of the frequency multiplying unit 625 . The second switch unit 620 transfers the selected output to the clock reproduction unit 630 .
[0100] The clock reproduction unit 630 extracts a 10-bit clock signal from the 10-bit serial code input through the second switch unit 620 , and provides the signal to the IDLE code detection unit 635 , the parallel conversion unit 645 , and the data clock generation unit 665 . The data clock generation unit 665 converts the 10-bit code clock input from the clock reproduction unit 630 , into an 8-bit data clock and provides the clock signal to the MB810 decoder 655 and the 8B/10B decoder 660 .
[0101] The IDLE 635 detects +K28.5/−K28.5 and +K28.7/−K28.7 codes that are IDLE codes to recognize as the boundary of a 10-bit code, and transfers input codes in units of 10-bit codes, to the mode detection unit 640 . At this time, if K28.7 code is detected contiguously twice or more, the IDLE code detection unit 635 recognizes the corresponding code as IDLE code.
[0102] The mode detection unit 640 analyzes the contents of IDLE code input from the IDLE code detection unit 635 and determines whether the dual mode decoder according to the present invention is to be used as the MB810 decoder 655 or the 8B/10B decoder 660 . The mode detection unit 640 transfers mode determination information to the first switch unit 650 , the second selection unit 670 , the MB810 decoder 655 , and the 8B/10B decoder 660 . Also, when there is a user request, the mode detection unit 640 operates the second switch unit 620 so that the output of the frequency multiplying unit 625 is transferred to the clock reproduction unit 630 .
[0103] The parallel conversion unit 645 converts the 10-bit serial code input from the first switch unit 615 into a 10-bit parallel code and transfers the parallel code to the first selection unit 650 . The first selection unit 650 transfers the 10-bit parallel code input from the parallel conversion unit 645 to one of the MB810 decoder 655 and the 8B/10B decoder 660 according to the mode determination information input from the mode detection unit 640 .
[0104] The MB810 decoder 655 converts the 10-bit code information input from the first selection unit 650 into 8-bit data information according to the MB810 decoding method explained referring to FIG. 13 . The 8-bit data information output from the MB810 decoder 655 is output as 8-bit parallel data, clock information and control code, through the second selection unit 670 .
[0105] The 8B/10B decoder 660 converts the 10-bit code information into 8-bit data information according to the 8B/10B decoding method. The 8-bit data information output from the 8B/10B decoder 660 is output as 8-bit parallel data, clock information and control code, through the second selection unit 670 .
[0106] FIGS. 16 a and 16 b are flowcharts of the steps performed by a dual mode processing method according to the present invention. The flowcharts of FIGS. 16 a and 16 b are showing a process for the mode detection unit 640 determining a mode of the decoder when the dual mode decoder shown in FIG. 15 is initialized.
[0107] Referring to FIGS. 16 a and 16 b, if the dual mode decoder is initialized in step S 700 , the mode detection unit 640 sets count value N of the counter arranged inside the mode detection unit 640 , to 0 in step S 705 . The initialization operation of the dual mode decoder may be set so that the initialization operation is performed when an enough IDLE time continues according to the set state. The counter is an element counting the number of IDLE codes in order to determine the operation mode of the dual mode decoder. After the initialization is performed, the mode detection unit 640 receives a code from the IDLE code detection unit 635 in step S 710 . Then, the mode detection unit 640 checks whether or not the received code is +K28.7 that is the IDLE code of the MB810 decoder in step 715 . If the input code is +K28.7, the mode detection unit 640 increases count value N of the counter by 1 and again receives a next code from the IDLE code detection unit 635 in step S 720 .
[0108] Next, the mode detection unit 640 checks whether or not the code input in the step S 720 is −K28.7 in step S 725 . If the code input in the step S 720 is −K28.7, the mode detection unit 640 compares the number of K28.7 codes input till that time, with a set reference value M 1 in step S 730 . Reference value M 1 is a value preset by the user and a value defined in IEEE 802.3 specifications may be set as reference value M 1 . If it is determined that the number of K28.7 codes input till that time is equal to or greater than reference value M 1 , the mode detection unit 640 outputs mode determination information indicating that the dual mode decoder according to the present invention operates as the MB810 decoder in step S 735 . Unlike this, if it is determined that the number of K28.7 codes input till that time is less than reference value M 1 , the step S 710 is performed. If it is determined that the code input in the step S 720 is not −K28.7, the mode detection unit 640 performs step S 755 .
[0109] Meanwhile, if it is determined that the code input in the step S 710 is not +K28.7, the mode detection unit 640 checks whether or not the code input in the step S 710 is −K28.7 in step S 740 . If the code input in the step S 710 is −K28.7, the mode detection unit 640 increases count value N of the counter by 1, and again receives a next code from the IDLE code detection unit 635 in step S 745 . Then, the mode detection unit 640 checks whether or not the code input in the step S 745 is +K28.7 in step S 750 . If the code input in the step S 745 is +K28.7, the mode detection unit 640 performs the step S 730 . Unlike this, if the code input in the step S 745 is not +K28.7, the mode detection unit 640 checks whether or not the code input in the step S 745 is +K28.5 that is the IDLE code of the 8B/10B decoder in the step S 755 . If the code input in the step S 710 is not −K28.7, the mode detection unit 640 performs the step S 755 . The step S 755 is performed when the code received by the mode detection unit in the step S 710 is neither +K28.7 nor −K28.7, when the code input in the step S 720 is not −K28.7, and when the code input in the step S 745 is not +K28.7.
[0110] If the result of performing the step S 755 indicates that the input code is +K28.5, the mode detection unit 640 again receives a next code from the IDLE code detection unit 635 in step S 760 . Then, the mode detection unit 640 checks whether or not the code input in the step S 760 is D5.6 code of 8B/10B (that is, 1010010110) in step S 765 . If the code input in the step S 760 is D5.6 code, the mode detection unit 640 increases count value N of the counter by 1 in step S 770 . After increasing count value N of the counter by 1, the mode detection unit 640 checks whether or not the number of K28.5 codes received till that time is equal to or greater than reference number M 2 in step S 775 . Reference number M 2 is a value preset by the user and a value defined in IEEE 802.3 specifications may be set as reference number M 2 . If the number of K28.5 codes continuously received till that time is equal to or greater than reference number M 2 , the mode detection unit 640 outputs mode determination information indicating that the dual mode decoder according to the present invention operates as the 8B/10B decoder in step S 780 . Unlike this, if the number of K28.7 codes input till that time is less than set reference number M 2 , the mode detection unit 640 performs the step S 710 .
[0111] Meanwhile, if the code input in the step S 760 is not D5.6 code, the mode detection unit checks whether the code input in the step S 760 is a control code in step S 800 . If the code input in the step S 760 is a control code, the mode detection unit 640 performs the step S 710 . Unlike this, if the code input in the step S 760 is not a control code, the mode detection unit 640 determines that an error such as a transmission line error has occurred, and performs the step S 700 or performs a diagnostic operation such as transmission of a test code in step S 805 .
[0112] Meanwhile, if the result of performing the step S 755 indicates that the codes input in the steps S 710 , S 720 , and S 745 are not +K28.5, the mode detection unit 640 checks whether or not the codes input in the steps S 710 , S 720 , and S 745 are −K28.5 in step are −K28.5 in step S 785 . If the codes input in the steps S 710 , S 720 , and S 745 are −K28.5, the mode detection unit again receives a next code from the IDLE code detection unit 635 in step S 790 . Then, the mode detection unit 640 checks whether or not the code input in the step S 790 is D16.2 in step S 795 . If the code input in the step S 790 is D16.2, the mode detection unit 640 performs the step S 770 . Unlike this, if the code input in the step S 790 is not D16.2, the mode detection unit 640 performs the step S 800 .
[0113] According to the MB810 line code apparatus and MB810 code generation method using the control codes according to the present invention, the transmission bandwidth becomes half that of the prior art including the 8B/10B codes such that when an identical transmission medium is used, relatively long-distance transmission is enabled. In addition, the present invention can be applied with the MB810 codes without changing the prior art 8B/10B code method such that the dual mode operation allowing the user to select a desired line code can be performed. Furthermore, the serial conversion apparatus, the parallel conversion apparatus, the clock reproducing unit and data clock generation unit of the decoder, and code clock generation unit of the encoder in the prior art 8B/10B code apparatus can be utilized without change.
[0114] Meanwhile, according to the present invention, the low pass filter used in the MB810 encoder and the low pass filter used in the MB810 decoder have characteristics identical to the roll off characteristics of the low pass filters of the 8B/10B encoder and decoder. In addition, the cut-off frequency by combination of the low pass filter of the MB810 encoder and the low pass filter used in the MB810 decoder is half the cut-off frequency by combination of the low pass filter of the 8B/10B encoder and the low pass filter of the 8B/10B decoder and is much easier to be implemented by an identical technology. In particular, the bandwidth required by the amplifier of the MB810 encoder is half the bandwidth required by the amplifier of the 8B/10B encoder and can be implemented easily by an identical technology.
[0115] Furthermore, when a code is set, a complementary code is always used such that the operation of the decoder is simplified. Also, transition from all states is available and K28.7 that has a single pair and is a reserved code in the 8B/10B code system is set as IDLE code. By doing so, when the apparatus operates in dual mode, the 8B/10B codes and MB810 codes can be easily distinguished and the structure in the physical layer is simplified.
[0116] The invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission through the Internet). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
[0117] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. Such variations and modifications are within the scope of the present invention defined in the appended claims. | MB810 encoder and/or decoder, dual mode encoder and/or decoder, and a method for generating MB810 codes are provided. The method for generating MB810 codes comprises: forming 12 state points in the form of a 4×3 matrix on a state transition map formed with binary unit digital sum variation & alternate sum variation (BUDA) to generate a 10-bit code from 8-bit data; outputting a 10-bit code from a predetermined state point forming the matrix; selecting codes forming a complementary pair from a set of codes capable of arriving at state points forming the matrix; selecting codes forming the 12 state points by supplementing state points lacked in the codes forming a complementary pair; selecting control codes including IDLE code from the codes forming the 12 state points; and removing codes generating the IDLE code by a bit string between neighboring codes among the codes forming the 12 state points. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to removable camper shell tops for use with pickup trucks, and is more particularly concerned with a removably attachable soft shell top which includes provisions for attaching a roof rack.
The popularity of camper tops for pickup truck is well known. They are used to convert the bed of the pickup truck into a sizable enclosed space. With a camper top, a pickup may be used as a recreational vehicle or may simply be used as an enclosed truck for protecting cargo from the elements.
A camper top for a pickup is advantageous in that it may be removed so that the truck serves a dual purpose. Without the top, the truck may be used as an open-bed pickup. With the top, the truck is converted into an enclosed camper. However, the construction of known camper tops tends to thwart this advantage, because typical hard shell camper tops tend to be heavy and awkward and therefore not easy to remove or install. Thus, the owners of camper tops are often discouraged from removing them once installed, except in the most urgent need.
Various camper top constructions have been devised in an attempt to circumvent this disadvantage. U.S. Pat. No. 4,815,786 to McRay, for example, discloses a collapsible camper top with telescoping metal side walls that collapses into a stored configuration in the bed of the pickup permitting the pickup bed to be used while the collapsed camper top is stored there. Unfortunately, the collapsed McRay top occupies a substantial portion of the available cargo space in the bed.
In attempts to circumvent the above-noted disadvantage, camper tops have been devised that are formed of a light weight fabric or plastic covering that is installed over a removable or collapsible frame on a pickup truck body. An example of this type of camper top is found in U.S. Pat. No. 4,813,734 to Hoover. Hoover discloses a frame consisting of interconnected sections of PVC pipe, where the frame rests in the pickup bed and is covered by a tarp laced to the frame by lengths of cord. While Hoover does provide a lightweight soft shell camper top, the PVC frame is not securely attached to the pickup bed and is incapable of supporting structural loads placed on the frame by, for example, a roof rack. Further, the tarp-covering is fixed to the PVC frame in such a manner that convenient access to the pickup truck bed is precluded.
The problems of soft shell camper tops for pickups are heightened when it is desired to equip the top with a roof rack, a feature in great demand by consumers. Roof racks are typically used by consumers to carry oversized and/or awkward loads such as bicycles, skis, camping gear, and other recreational equipment. Prior art soft shell tops may not have sufficient strength to support such loads which are typically on the order of 200-300 pounds. It is not presently believed that any prior art soft shell tops include provisions for a roof rack.
What is needed therefore is a soft shell camper top that is securely, yet removably, attachable to a pickup truck bed. Such a top should be equipped with features that allow for easy loading and unloading of gear or cargo from the sides of the pickup bed. Such a top should include provisions for attaching a roof rack and should have sufficient structural strength to support loads of at least 200-300 pounds in order to safely handle the weight of typical recreational equipment.
SUMMARY OF THE INVENTION
The present invention provides a soft shell camper top for a pickup truck that includes provisions for a roof rack and is capable of safely supporting the weight of the recreational equipment typically transported on roof racks. The soft shell top may be quickly and easily attached to, and removed from, a pickup truck bed. The top additionally includes innovative side panels and other features which allow for side access to the truck bed and for easy loading and unloading of cargo carried in the truck bed.
The soft shell camper top of the present invention includes a space frame, and a flexible outer covering. The camper top may optionally be equipped with a roof rack. The frame may be rigidly attached to the upper rails of a pickup truck bed and is preferably formed from stainless or powder coated steel. The frame includes a pair of longitudinal side rails which may be bolted or clamped to the truck bed. The frame also includes a plurality of lateral hoop members which closely conform to the shape of the pickup truck cab and which support the flexible covering. The hoop members laterally span the truck bed attaching to each opposing frame side rail. The frame further includes a plurality of longitudinal spreader bars. The spreader bars have provisions for mounting a roof rack and may be arranged in a variety of configurations to position the roof rack at different locations over the soft shell top. The optional roof rack is designed to be removably attachable to the spreader bars. The roof rack may carry typical recreational equipment and is preferably formed from steel.
The outer covering is flexible and foldable and shaped to fit over the space frame and to be secured in position so as to define a sizable functional enclosed camper space. The covering may be formed from any suitable material, but is preferably formed from a woven fabric of synthetic fibers. The frame and covering are formed to provide an aerodynamically desirable profile which permits the vehicle to be driven comfortably at typical freeway speeds with the camper top installed.
Other features and advantages of the invention will become more apparent from the following detailed description of the invention, when taken in conjunction with the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical pickup truck with the soft shell camper top of the present invention situated thereon.
FIG. 2 is a perspective view of a frame for a soft shell camper top in accordance with the present invention.
FIG. 3 is a section view, taken along the line a—a, of the frame shown in FIG. 1 .
FIG. 4 is a perspective view of an outer covering, including a detail of a longitudinal tensioning strap, for a soft shell camper top in accordance with the present invention.
FIG. 5 is a top view of an outer covering for a soft shell camper top in accordance with the present invention.
FIG. 6 is a perspective view of a soft shell camper top, showing details of a roof-rack attachment, in accordance with the present invention.
FIG. 7 is a perspective view of an alternate embodiment of a rail and friction joint suitable for use in the frame which comprises part of the present invention.
FIG. 8 is a section view, taken along the line b—b, of the frame rail shown in FIG. 7 .
FIG. 9 depicts alternative attachment hardware utilizing clamps for attaching the frame of FIG. 2 to the pickup truck.
FIG. 10 is a top view of the attachment hardware shown in FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, there is shown a soft shell camper top 10 in accordance with the present invention. The camper top includes generally a frame 12 , an outer cover 14 , a tailgate strip 15 , and optionally a roof rack 16 . The camper top is shown mounted on a typical pickup truck 18 . The truck includes, a cab 20 , a cab back wall 21 , a bed 22 , side walls 24 , a front wall 26 , and a tailgate 28 .
Referring now to FIGS. 2 and 3, the frame 12 is illustrated in greater detail. The frame includes a first elongate longitudinal rail member 30 and a second elongate longitudinal rail member 32 , which are preferably rectangular in transverse cross section. The longitudinal rails are designed to conform to, and rest on, the top faces of the pickup truck side panels 24 . Attached to the bottom surface of the rails (that surface adjacent the top surface of pickup truck side panels) is a layer of non-marring material 31 . The layer of non-marring material 31 prevents damage to the truck's paint which would otherwise result due to abrasion between the rails and the truck sides. The non-marring material layer is preferably composed of high density closed cell foam. Numerous other polymer materials such as polyurethane, polyethylene, and polyamide in foam or sheet form, as well as rubber are also suitable. The non-marring material layer may be attached to the longitudinal rails by adhesive bonding and other suitable techniques.
Disposed adjacent the rear or tailgate end of the longitudinal rails are rear anchors 33 which in combination with a set of front anchors provide tie-off points for snugly securing the outer cover 14 about the frame. Spaced along the sides of the rails are snaps 52 which also serve to secure the cover. The snaps are merely illustrative of one method of securing the outer cover along of the sides of the rails. Any other attachment means or combination of attachment means are suitable for securing the cover to the frame rails. Other suitable methods of attachment include hook and loop attachments used either alone or in combination with snaps.
Referring now to FIG. 3, the longitudinal rails 30 and 32 are securely attached to the side panels 24 of the pickup truck. The rails may be bolted, clamped, or otherwise attached to the truck side panels. Preferably, the rails are equipped with clearance holes 46 which pass through the rails and mate with corresponding holes formed in a top surface 23 of the truck bed side panel 24 . Through-bolts 48 which pass through the clearance holes are used to attach the rails to the truck side panels, as is shown in FIG. 3 . Those skilled in the art will understand that appropriate nuts and washers are to be used in conjunction with the through-bolts. For short bed pickups two through-bolts per side are preferred. For long bed pickups three through-bolts per side are preferred. The arrangement shown in FIG. 3 is meant to be exemplary only. Other fastening arrangements are suitable and known in the art.
Referring now to FIGS. 9 and 10, a method for clamping the longitudinal rails to a truck bed side panel 24 is shown. In this approach a clamp 90 is attached to a lip 27 of the pickup truck side panel 24 . The clamp comprises an inner clamp plate 94 and an outer clamp plate 92 . Attached to the outer clamp plate is a cylindrical member 96 . One or more clamp bolts 100 are used to clamp the inner and outer clamp plates to the truck bed lip 27 . In applications where clamping is used as the method of attaching the longitudinal rails to the pickup truck bed, the rails are equipped with fittings 98 . Each fitting includes a clearance hole 102 which interfaces with the cylindrical member 96 of the outer clamp plate. The longitudinal rails are attached to the clamps by means of a through-bolt 104 which passes through the clearance hole 102 and the cylindrical member 96 of the outer clamp plate. Although, the through bolt 104 is illustrated in the exemplary embodiment, those skilled in the art will realize that pins such as ball-lock pins may be used in place of the through-bolt. The method and hardware described above for clamping the longitudinal rails to the truck bed is provided for situations where it may be undesirable to drill mounting holes in the truck bed.
Attached to the opposing longitudinal rail members 30 and 32 , and laterally spanning the pickup truck bed 22 , are front and rear hoop members 34 and 36 respectively. Between the front and rear hoop members is at least one intermediate hoop member 38 . Each hoop member includes two generally inwardly sloping upright portions 42 , which are interconnected by a horizontal portion 40 . The hoop members 34 - 38 are preferably formed from circular tubing, the ends of which terminate in weldments 50 . The weldments 50 provide for connection of the hoop members to the longitudinal rails. Preferably the weldments and the longitudinal rails are match drilled to allow for bolted connections between the hoop members and the rail members.
In order to maintain a desirable aerodynamic profile, the hoop members generally conform to the outline of the cab back wall 21 . Generally, to prevent undue vibration at typical freeway speeds (60-70 mph), the horizontal portion 40 of the hoop members should be within a range of about one inch above or below the horizontal plane defined by the top of the pickup truck cab 20 . In addition, the generally vertical portions 42 of the hoop members should be limited in inward or outward extent to about one inch with respect to the generally vertical portions of the cab back wall.
Attached between each adjacent hoop member, is at least one spreader bar 54 . The spreader bars are preferably of circular cross-section with flanged ends 56 which mate with weldments 58 disposed near the top of the vertical portions 42 of the hoop members. The flanged ends of the spreader bars and the weldments 58 are preferably drilled with clearance holes to allow for bolted connections between the hoop members and the spreader bars. The spreader bars may also include roof rack attachment plates 82 which are typically welded to the spreader bars. The attachment plates are drilled with a predetermined bolt pattern to allow for the easy “bolt on” attachment of a roof rack. When the attachment plates 82 are disposed adjacent the ends of the spreader bars as shown in FIG. 2, the spreader bars may be repositioned or flipped 180 degrees to provide alternate positions for the roof rack.
The frame 12 also includes a head rail 44 , which is preferably of square cross-section and is preferably attached to the rail members 30 and 32 by bolts and angle fittings. The head rail conforms to and rests upon the top face of the pickup truck front panel 26 . The head rail is preferably equipped with the front anchor fittings 33 which provide the front attachment points for the cover 14 . The front anchor fittings may also be located on the longitudinal rails 30 and 32 .
The preferred material for the structural members which comprise the frame 12 , i.e., the rails 30 and 32 , the hoops 34 - 38 , the spreader bars 54 , and the head rail 44 , is either stainless steel or powder coated steel. However, there are many other suitable materials which include, but are not limited to, aluminum, titanium, and structural plastics.
Referring again to FIG. 1, a tailgate strip member 15 is shown. Similar to the longitudinal rail members 30 and 32 , the strip is equipped with snaps 52 which serve to securely fasten the rear portion of the outer cover 14 . As with the longitudinal rails, the snaps may be substituted with any other suitable attachment means such as hook and loop attachments. Other suitable substitutes for snaps are known in the art. The tail gate strip is designed to rest on and conform to the top or side surface of the tailgate 28 . Preferably, the strip is formed from aluminum and is adhesively bonded to the tailgate. Other methods of attachment, such as fasteners are also suitable. In some situations, it may be preferable to weld or braze the tailgate strap to the tailgate, typically in these situations, the strap will be made from a compatible ferrous material.
Referring to FIGS. 7 and 8, the longitudinal rails 30 and 32 may take an alternate form as shown. In this embodiment, the rails 30 and 32 are open in transverse cross section such that clamp blocks 84 may be slidably received within the rails. A slotted rectangular cross section is illustrated. With this type of rail, the hoop members 34 - 38 are attached to the rails by means of a plurality of bolts 48 which pass through holes in the hoop weldments 50 , and through the slot in the rail, and thread into the clamp block. Tightening the bolts creates a friction joint that secures the hoop members to the rails. This arrangement allows the hoop members to be readily positioned at different locations along rail.
In the above description of the frame 12 , preferred cross sectional shapes are given for each frame member. Those skilled in the art will understand that a wide range of tubing shapes, sizes, and thickness may be used to form the above described structural elements. Thus, the shapes of the preferred embodiment are meant to be exemplary only and are not meant to be limiting. In addition, in the preferred embodiment all of the attachments between the structural members are in the form of bolted joints. This form of attachment allows for relative ease of assembly and allows for disassembly of the frame structure. However, this description is also meant to exemplary and is not meant to be limiting. Other forms of mechanical fasteners, such as ball-lock pins may substituted for bolted joints. Further, where disassembly of the frame structure is not required, the structural members which comprise the frame may be permanently attached to each other by welding, brazing, bonding, or other suitable methods.
Referring now to FIGS. 1, 4 and 5 , the outer cover 14 of the present invention includes top panels 60 , side panels 62 , a rear panel 64 which typically includes a transparent window portion 68 , and a front panel 74 (FIG. 5 ). Preferably, two top panels are used in short bed pickup truck applications and three top panels are used in long bed pickup truck applications. Each side, front, and rear panel has a first closed or “rolled down” position (FIG. 4) in which the panel is secured to a corresponding longitudinal rail 30 or 32 , head rail 44 , or tailgate strip member 15 . Each panel also has a second open or “rolled up” position (FIG. 1) where the panel is secured to a corresponding spreader bar 54 in the case of the side panels, or to the front or rear hoop members, 34 or 36 , in the case of the front and rear panels. Each panel may be rolled up or down independently of the other panels.
Referring now to FIG. 4, the outer cover is equipped at each corner between the side curtains and the front or rear curtain with a loop and hook fastener closure 66 . Each closure 66 comprises a flap 65 which contains the loop portion. The flaps are typically sewn or formed into the front and rear panels. The closures 66 also include a hook or nap portion 67 . The hook portion is typically sewn or formed into the side panels. Mating the loop and hook portions of the closure produces an easily resealable, yet strong, fabric joint. The closures function to seal the corners between the side panels and the front and rear panels from any dust, dirt, rain, or snow, which may be present due to inclement weather, off-road driving conditions, or other conditions.
With continuing reference to FIG. 4, the side panels 62 each include snaps 52 , or other suitable fasteners, which mate with the snaps on the respective rail members 30 and 32 . The front and rear panels 74 and 64 also include the snaps 52 , or other suitable fasteners, which mate with the snaps on the head rail 44 and tailgate strip 15 respectively. The snaps serve to removably attach the panels to the corresponding frame members and thereby hold the panels in the first closed or “rolled down” position, as is shown in FIG. 4 .
Referring now to FIGS. 1 and 4, the top panels 60 of the outer cover 14 include strap and buckle assemblies 70 which serve to hold the outer cover panels (side, front, and rear) in the rolled up position. The top panels 60 also includes continuous front and rear channels 78 sewn or formed into the top portion's front and rear edges. The channels provide a passage through which is threaded a tie-down cord 76 . The tie-down cord in the front and rear channels is secured to the front and rear anchors 33 as is shown in FIG. 1 . The channels, tie-down cord, and anchors provide secure means for snugging the outer cover 14 to the frame 12 . The tie-down cord functions as a tensioning or biasing member creating a snug fit between the outer cover and the frame with only a modest “pulling” of the cord about the anchors.
Referring again to FIG. 4, the primary means of attaching the outer cover 14 to the frame 12 , are a plurality of tensioning straps 72 . The straps are sewn or formed into the front and rear edges of the upper panels 60 of the outer cover 14 and are disposed below the respective front and rear hoop members 34 and 36 . The straps run longitudinally to an intermediate hoop member 38 . By means of buckles 73 , each strap may be pulled snug, the effect of which is to tension or stretch the portion of the top between the hoop members to which the straps are attached. This feature tends to reduce flapping of the outer cover when the vehicle is driven at freeway speeds (60-70 mph). Generally, three sets of tension straps are preferred. However, the number of straps is dependant on the size of the vehicle, i.e., full size trucks may require more straps and mini-pickups may require less. As used here, a set of straps refers to one strap running from under the rear hoop 36 to the intermediate hoop 38 and a second strap running from under the front hoop 34 to the intermediate hoop 38 , where the straps are approximately co-linear and are disposed adjacent each other at the intermediate hoop, as is shown in FIG. 4 .
The outer covering 14 may be constructed of any suitable weather resistant material. The preferred material is woven fabric made from an acrylic fiber which is coated with a water repellent material. Such a fabric is available from Glen Raven Mills, Inc., located in Glen Raven, N.C., and is sold under the trade name SUNBRELA. Other suitable materials include waterproofed canvas, nylon, and other polymer films and fabrics.
Referring now to FIGS. 1 and 6, there is illustrated a roof rack 16 which is designed specifically for use with the soft shell camper top 10 of the present invention. The roof rack comprises a plurality of uprights 86 and a plurality of crossbars 88 . The uprights and cross bars are shown attached to the soft shell camper top. In the preferred embodiment, the uprights attach to the attachment fittings 82 (FIG. 2) by means of angle fittings 84 . For ease of installation and removal, a bolted connection is preferred. FIG. 6 illustrates the cutouts 80 in the side curtains 62 which provide access to the attachment weldments 82 .
Presently, there are also a variety of roof racks commercially available which may be adapted for use with the camper top of the present invention. Typically, these roof racks include an interface which attaches the rack to a vehicle by means of clamping to the vehicle's rain gutter or upper door jamb. There are yet other methods of attachment in use. Those skilled in the art will understand that the attachment weldments 82 may be modified to accommodate various roof rack attachment interfaces. Accordingly, it is not intended that the method of attachment or design of the attachment weldments 82 be limited to that disclosed in the preferred embodiment.
Shaped in the general manner described and illustrated herein, the soft shell camper top 10 of the present invention provides several advantages over the prior art. The camper top presents an aerodynamic profile permitting the truck to be driven comfortably at freeway speeds without introducing significant adverse aerodynamic reactions that could otherwise lead to instability of the vehicle or cause poor gas milage. The soft shell top of the present invention is of comparatively light weight in contrast to typical hard shell camper tops and therefore may be readily installed and removed from the vehicle as the needs or desires of the owner dictate. Another advantage of the soft shell top of the present invention is that the side curtains 62 and the front and rear curtains 64 and 74 may be rolled up to allow easy access to the cargo bed. It will also be appreciated that the new camper top may be installed by only one person using a few simple tools.
While only the presently preferred embodiment has been described in detail, as will be apparent to those skilled in the art, modifications and improvements may be made to the device disclosed herein without departing from the scope of the invention. Accordingly, it is not intended that the invention be limited except as by the appended claims. | A soft shell camper top for use on pickup truck cargo compartments is disclosed. The invention consists of a space frame and a flexible outer covering. The frame is removably attachable to the pickup truck bed and includes provisions for the attachment of a roof rack. The outer covering includes front and rear curtains and side curtains. The curtains may be securely fixed to attachments on the frame to protect cargo from the elements or may be rolled up to facilitate easy access to the truck bed. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Serial No. 60/237,732 filed by C. H. Shang et al. on Oct. 5, 2000 and entitled “High Performance Nanostructured Materials and Methods of Making the Same”, which is incorporated herein by reference.
GOVERNMENT INTEREST
The United States Government has certain rights in this invention pursuant to Contract Number N00014-98-10600 supported by ONR.
BACKGROUND
Nanostructured materials are of considerable interest due to their unique mechanical properties and structural versatility. Materials with grain sizes less than one micrometer have been shown to have significantly improved mechanical properties compared to corresponding coarse-grained materials under certain conditions. However, the structure of the starting materials, physical treatments, and fabrication conditions can significantly impact the performance of nanostructured materials for specific applications.
Nanostructured materials with high yield strength, hardness, and superplasticity have previously been fabricated. However, poor ductility was observed to accompany these mechanical characteristics especially in high-strength intermetallic compounds. Previously, available nanostructured intermetallics failed in the elastic regime under tensile stresses with virtually no plastic strain-to-failure at room temperature, severely limiting their use in industrial applications. The observed extreme brittleness in nanostructured materials, in particular intermetallics, is attributed to flaws or porosity produced during the fabrication process.
Fabrication of nanostructured materials commonly followed a “two-step” consolidation method, which involves synthesizing various powders of nanometer size and then consolidating them into bulk articles using such processes as hot pressing. However, the “two step” consolidation processes cannot prevent the formation of micro-flaws or porosity in the final products.
“One step” methods of nanostructured synthesis (e.g., electro-deposition, crystallization of amorphous solids, and severe plastic deformation) produce materials without residual porosity, but have several disadvantages. First, nanostructured intermetallics made by these methods are extremely brittle. Second, it is difficult to electro-deposit bulk nanostructured intermetallics because of the accumulation of deposition stresses. Thus, known one-step methods of nanostructured synthesis fail to produce materials having both high tensile strength and ductility.
The problem of poor ductility in nanostructured materials is widely recognized in the scientific community. For example, the highest reported strength for nanostructured FeAl intermetallic was found to be 2.3 GPa. However, the material exhibited such poor ductility that the strength was only measurable under compression. In addition, forming bulk amorphous solids is technically complex and not practical for single-phase metallic materials. Single phase solids can be simpler to make, more stable, and may be desirable due to their magnetic, electrical, or optical properties. However single-phase intermetallics have not shown a combination of high strength and good ductility in tension.
Decreasing the grain size is important for increasing strength, but grain size should be decreased while reducing or eliminating the flaws (cracks) and porosity in the materials. Achieving fine grain sizes using severe plastic deformation involving enormous strains by torsion of several hundred percent has met with very limited success in the improvement of tensile ductility. For instance, heterogeneous strain of ˜400% at 200° C., followed by homogeneous strain of ˜800% at 400° C., and by additional strain of ˜400% at 200° C., produces grain sizes of only approximately 1.2 micrometers for Al—Mg—Li—Zr alloys.
Tempering can be used to enhance the toughness of a hardened martensitic phase by converting the metastable martensite to a structure of fine carbide particles in ferrite. However, the tempering process results in materials with enhanced hardness but low ductility.
SUMMARY OF THE INVENTION
Preferred embodiments of the invention provide new nanostructured materials and methods for preparing nanostructured materials having increased tensile strength and ductility, increased hardness, and very fine grain sizes making such materials useful for a variety of applications such as rotors, electric generators, magnetic bearings, aerospace and many other structural and nonstructural applications. The preferred nanostructured materials have tensile yield strengths from at least about 1.5 to about 2.3 GPa and a tensile ductility from at least 1%.
Preferred embodiments of the invention also provide a method of making a nanostructured material comprising melting a metallic material into a liquid state, solidifying the material, deforming the material, forming a plurality of dislocation cell structures, annealing the deformed material at a temperature from about 0.30 to about 0.70 of the material's absolute melting temperature, and cooling the material.
Advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned through the practice of the invention. The advantages of the invention will be attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary and the following detailed description of the preferred embodiments of the invention should be read in conjunction with the accompanying drawings, in which:
FIG. 1 shows differential scanning calorimetry traces of as-rolled and annealed Hiperco Alloy 50HS, measured at a heating rate of 40° C. per minute;
FIG. 2 shows X-ray diffraction profiles for Hiperco Alloy 50HS: (a) as-rolled, and (b) annealed at 438° C. for five hours. The inset shows the discontinuous ring diffraction pattern. The clusters of diffraction spots are evidence for the growth of subgrains with low-angle grain boundaries;
FIG. 3 is an image of a nanocrystalline FeCo-based intermetallic material taken by transmission electron microscopy, showing grain size ranging from tens to hundreds of nanometers of nanostructured material;
FIG. 4 is an image of a fracture surface for a nanocrystalline FeCo-based intermetallic with submicron dimples clearly showing the fracture is ductile;
FIG. 5 shows the results from room temperature tensile tests for nanocrystalline FeCo-based intermetallics;
FIG. 6 demonstrates room temperature strengths versus grain size of Hiperco Alloy 50HS samples;
FIG. 7 shows room temperature ductility versus grain size of Hiperco Alloy 50HS samples;
FIG. 8 shows Vickers hardness versus grain size for FeCo-based intermetallics; and
FIG. 9 shows Vickers hardness as a function of annealing time for Hiperco Alloy 50HS
DETAILED DESCRIPTION
Preferred embodiments and applications of the invention will be described below. Other embodiments may be realized and structural or logical changes may be made to the embodiments without departing from the spirit or scope of the invention. Although the preferred embodiments disclosed herein have been particularly described as applied to a cold-rolled nanostructured material (and methods for producing the same), it should be readily apparent that the invention may be embodied in any composition (or method for producing the same) having the same or similar problems.
In accordance with preferred embodiments of the invention, nanostructured materials are provided having a unique combination of ultrahigh tensile yield strength and large tensile ductility. The nanostructured materials may be formed from any suitable material including, but not limited to pure metals (e.g., copper, nickel, iron), alloys, and intermetallic compounds (i.e., a particular chemical compound based on a definite atomic formula).
In accordance with a preferred embodiment, the nanostructured material has microstructures with a grain size ranging from about 10 nanometers to about 900 nanometers. The tensile yield strength of the nanostructured materials in accordance with a preferred embodiment of the invention is at least about 1.5 GPa, while the plastic strain-to-failure ratio is at least 1%. The precise mechanical properties desired can be achieved through controlled heat treatment in accordance with a preferred embodiment of the invention, as shown in FIG. 5 . Increased yield strengths may be as large as about 45% compared to the “as-rolled” condition. At the same time, the tensile ductilities are greatly increased due to the formation of flaw-free nanostructured materials.
The nanostructured materials in accordance with preferred embodiments of the invention are fully dense and free of flaws and porosity. “Fully dense” refers to materials that are have a density within 0.1% of their theoretical density. “Free of flaws and porosity” refers to materials that have less 0.1 vol % pores and no cracks at grain boundaries. “Controlled heat treatment” or annealing of deformed starting materials refers to heating the specimen in a controlled atmosphere with prescribed heat-up and ramp-down temperature rates and time periods, resulting in the formation of small, nanometer scale grains.
In a preferred embodiment, the intermetallic compounds are single-phase alloys which form highly ordered crystalline materials. The preferred intermetallic compounds used to make the materials, (hereinafter referred to as “starting material”), in accordance with preferred embodiments of the invention include a base material to which certain percentages of other elements may optionally be added. Preferred intermetallic compounds, for example, may include the FeCo-based intermetallic Hiperco Alloys 50 and 50HS, available from Carpenter Technology Inc. and described in U.S. Pat. No. 5,501,747, which is hereby incorporated by reference herein in its entirety. The chemical composition of the Hiperco Alloys in weight percent is:
Alloy Element
Composition in weight percent
C
0.003-0.02
Mn
0.10 max.
Si
0.10 max.
P
0.01 max.
S
0.003 max.
Cr
0.1 max.
Ni
0.2 max.
Mo
0.1 max.
Co
48-50
V
1.8-2.2
Nb
0.03-0.5
N
0.004 max.
O
0.006 max.
with iron as a balance.
In a preferred embodiment, plastic deformation is performed using a cold-rolling process, as described generally in U.S. Pat. No. 5,501,747, to achieve a reduction ratio typically from between about 50% to about 95%. In a preferred embodiment, the reduction ratio is at least 80%, and preferably more than 90%. The annealing temperature ranges from about 0.30 to about 0.70 of the material's absolute melting temperature for time periods ranging from less than about one hour to more than about 100 hours. The annealing can be conducted in a variety of atmospheres (e.g., hydrogen, argon, and nitrogen, air, etc.) as an application requires. Following annealing, the material is cooled at a cooling rate that can vary from less than about 1° C./minute to more than about 500° C./s. This process produces nanostructured materials having ultrafine grains with grain sizes from tens to hundreds of nanometers without noticeable grain growth when used at temperatures below the annealing temperature. Furthermore, the preferred nanostructured materials have the same crystal structure before and after heat treatment, as shown in FIG. 2, demonstrating that the phase structure remains the same, and that the acquired improved properties are due to microstructural improvements.
In a preferred embodiment, a method of producing nanostructured materials is provided by forming grains of nanometer size in the heavily deformed bulk articles through controlled heat treatments. Dislocation cell structures, ordering domains, and other chemical or phase defects act as driving forces to form nanometer-sized grains. Recrystallization and grain growth are employed to develop nanostructured microstructures of diversified grain sizes The properties of nanostructured materials depend sensitively on the grain sizes. Varying grain sizes permits one to tailor the tensile strength and ductility to meet particular needs of the material. The heat treatments can be conducted for a controlled period of time at a wide range of temperatures to drive the recovery and recrystallization processes. The preferred annealing temperature is generally between 0.30 and 0.70 of the absolute melting temperature (250° C.-950° C. for Hiperco Alloys 50HS) with an annealing time from 1000 hours to several seconds. More preferred is an annealing temperature in the range 0.37-0.53 of the absolute melting temperature with an annealing time from 50 hours to several minutes. The most preferred annealing temperature is from 0.39-0.44 of the absolute melting temperature with the annealing time ranging from 20 hours to about one hour. Recrystallizing plastically deformed ingots through controlled heat treatments results in nanostructured metals, alloys, and high strength intermetallics that are fully dense and free of flaws or porosity.
Grain size can be limited to less than about one micrometer by controlling the annealing temperature and time in accordance with a preferred embodiment of the invention. The controlled annealing process results in the release of energy as the defects in the material are eliminated.
FIG. 1 is a Differential Scanning Calorimetric (“DSC”) scan of Hiperco Alloy 50HS showing the endothermic heat flow as a function of temperature in comparing the “as-rolled” condition of the Hiperco Alloy to its condition after annealing. As shown in FIG. 1, the major recovery and recrystallization process of the Hiperco Alloy 50HS material occurs from between about 350 to about 705° C. Since FeCo 50HS melts at 1470° C., these temperatures correspond to 0.36 to 0.56 of the material's absolute melting temperature of 1743 Kelvin. A DSC scan is one of many tools known in the art that may be used to determine the temperature range of the recovery and recrystallization process for any given starting material. The process of cold-rolling deformation and subsequent controlled recrystallization may be repeated one or more times to obtain still finer grains and higher mechanical strengths.
In accordance with a preferred embodiment, nanostructured materials contain niobium carbide (NbCx) particles as retarders for grain growth. Compared with the more than 99 wt % major phase, however, these second phase particles occupy only a small portion in volume. Microalloying elements such as Nb contained in the nanostructured material preferably impede grain growth by nucleating particles at grain boundaries or by Nb atoms preferentially segregating to grain boundaries to act as a grain refiner. The use of Nb in the nanostructured materials is a preferred method of maintaining the structural stability of the materials.
It is to be understood that the application of the invention to a specific problem or environment will be within the capabilities of one having ordinary skill in the art in light of the teachings contained herein. The following examples further illustrate preferred embodiments of the invention.
EXAMPLE 1
Nanostructured Materials with Tensile Strength Between 1.9 and 2.3 GPA and Plastic Strain-to-failure Between 1.3% and 5.5%
Hiperco Alloy 50HS (Co 48.68%, V 1.89%, Nb 0.31%, C 0.01%, Ni 0.11%, Mn 0.04%, Si 0.03%, Cr 0.05%, and balanced with Fe) was cold-rolled to 152.4 micrometers after rolling reduction of 92.6%. The cold-rolled sheets were annealed in an ultrahigh purity hydrogen atmosphere at a temperature of 438° C. for five hours. The ramping rate was 2-3° C./minute. To establish ordered intermetallic structures that possess superior soft magnetic properties, the cooling rate after annealing was set at 1° C./min to 316° C. Based on the examination results of differential scanning calorimetric, cross-section high-resolution field emission electron microscopy, and transmission electron microscopy the nucleation period of the recrystallization process was largely completed after the above heat treatment, and the cold-rolled alloys were successfully transformed into nanostructured materials.
The grain sizes of the above processed nanostructured materials ranged from tens to hundreds of nanometers, with an average grain size of about 99 nanometers. The lower yield strengths ranged from 1.9 GPa to more than 2.3 GPa depending on the test orientation with respect to the rolling direction. The plastic strain-to-failure was 1.3% to more than 5.0% depending on the loading direction. The in-plane Vickers hardness was as high as 6.4 GPa.
EXAMPLE 2
Nanostructured Materials with Tensile Strength Between 1.3 and 1.5 GPA and Ductility Between 11% AND 18%
Hiperco Alloy 50HS alloy sheets were annealed at 650° C. for one hour. The other conditions were the same as those in EXAMPLE 1. The average grain sizes of these samples were 287 nanometers. The lower yield strengths ranged from 1.3 GPa to more than 1.5 GPa depending on the test orientation with respect to the rolling direction. The strain-to-failure was 11% to more than 18% depending on the loading direction.
EXAMPLE 3
Nanostructured Intermetallic Materials with Fine Grain Size and High Ductility
Nanostructured intermetallics with an average grain size of 99 nm were fabricated by annealing Hiperco Alloy 50HS at 438° C. in a hydrogen atmosphere for five hours (FIG. 3 ). Fractographic studies show that the dominant fracture mode for the fabricated nanostructured intermetallics is ductile with submicron dimples (FIG. 4 ).
EXAMPLE 4
Adjusting the Mechanical Properties of Nanostructured Materials by Varying Grain Size and Heat Treatment
The mechanical properties of the nanostructured materials of the invention are adjusted by varying the grain size and heat treatment of the materials. Decreasing the grain size (i.e., through use of a lower annealing temperature) increases the tensile strength and decreases the ductility (FIGS. 5 and 6 ). In contrast, increasing the grain size (i.e., through use of a higher annealing temperature), decreases tensile strength while increasing ductility (FIGS. 5 and 6 ). The lower yield tensile strengths follow a similar Hall-Petch relationship, whether samples are strained in the rolling or the transverse directions, with a slope of about 0.4 (FIG. 6 ). The ductility shows a peak around 500 nm, and decreases with reducing grain sizes (FIG. 7 ). The lowest ductility observed, about 1.3% plastic strain-to-failure, is significantly larger than that of as-rolled materials, and much larger than any other reported values for nanostructured intermetallics made by other methods.
EXAMPLE 5
Vickers Hardness on the Nanostructured Materials
The hardness of the samples was measured on a LECO microhardness tester (M-400) with Vickers indents (FIG. 8 ). At a temperature within the major recovery and recrystallization process, the Vickers hardness was found to increase logarithmically with the annealing time (FIG. 9 ), suggesting that the degree of recrystallization and grain growth increases with time at a fixed annealing temperature.
EXAMPLE 6
Additional Nanostructured Materials
The methods described in EXAMPLES 1-4 are applied to an a FeCo-based alloy consisting essentially of 48.78% cobalt, 1.92% vanadium, 0.05-0.31% niobium, 0.012% carbon, 0.1% nickel, balanced with iron cold-rolled to a reduction percentage of about 82.7% in thickness.
While preferred embodiments of the invention have been described and illustrated, it should be apparent that many modifications to the embodiments and implementations of the invention can be made without departing from the spirit or scope of the invention. While the illustrated embodiments have been described utilizing a cold-rolling and controlled annealing process to produce nanostructured materials of high tensile yield strength and high ductility, it should be readily apparent that other processes may be utilized (or steps added to the processes) to produce the unique nanostructured materials in accordance with the invention. Any form of plastic deformation, particularly a shape-changing process (e.g., forging, swagging, extrusion etc.), that results in the generation of numerous dislocation structures within existing grains may be utilized. To facilitate formation of fully dense ingots, the starting materials may be melted into a liquid state by vacuum induction melting or other suitable techniques, including vacuum-based resistive furnaces, electron beam melting, reduced atmosphere melting, etc.
Although the use of Hiperco Alloys has been described in detail, it should be apparent that any other intermetallic compound (or other metallic starting material) may be utilized in implementing the invention. Although the preferred embodiments have been described in particular application to bulk materials, it should be readily apparent that the invention may be applied to any number of other applications without departing from the scope of the invention.
Accordingly, the invention is not limited by the foregoing description, drawings, or specific examples enumerated herein, but only by the appended claims. | Preferred embodiments of the invention provide new nanostructured materials and methods for preparing nanostructured materials having increased tensile strength and ductility, increased hardness, and very fine grain sizes making such materials useful for a variety of applications such as rotors, electric generators, magnetic bearings, aerospace and many other structural and nonstructural applications. The preferred nanostructured materials have a tensile yield strength from at least about 1.9 to about 2.3 GPa and a tensile ductility from at least 1%. Preferred embodiments of the invention also provide a method of making a nanostructured material comprising melting a metallic material, solidifying the material, deforming the material, forming a plurality of dislocation cell structures, annealing the deformed material at a temperature from about 0.30 to about 0.70 of its absolute melting temperature, and cooling the material. | 2 |
FIELD OF INVENTION
The present invention relates to drilling fluid compositions and methods and, in particular, to drilling fluid compositions and methods in which reactive monomers are utilized to solidify the drilling fluid within a borehole.
BACKGROUND OF THE INVENTION
It is well known to utilize drilling fluids, or drilling muds, in the drilling of oil, gas, and water wells. Typically, the drilling fluid is recirculated down through a hollow drill pipe, across the face of the drill bit and upward through the borehole. The drilling fluid serves multiple functions including transporting borehole cuttings to the surface, preventing the entry of formation fluids into the borehole, sealing the walls of the hole, cooling and lubricating the drill bit and stem, and providing a medium for hydraulic power for bottomhole cleaning. As the drilling mud is recirculated a deposit of the fluid, the drilling fluid filter cake, is deposited along the borehole walls.
After the borehole has been drilled, a casing is run into the well and cemented into place by pumping cement into the casing, displacing the cement into the annulus between the casing and borehole wall with drilling fluid or water, and allowing the cement to harden. The effectiveness of the seal formed by the cement between the casing and borehole surfaces is dependent upon the bonding of the cement to the casing and borehole surfaces.
There are a number of inherent disadvantages in the conventional method of cementing the casing in the borehole. First, the drilling fluid utilized during drilling must be removed from the borehole prior to introducing cement into the casing. Further, the effectiveness of the seal between the casing and the borehole surfaces can be adversely affected by the drilling fluid filter cake. Therefore, a need exists for a more efficient means for cementing the casing within the borehole and a more effective means for sealing the casing with the borehole surfaces.
SUMMARY OF THE INVENTION
The present invention provides drilling fluid compositions, and methods, for solidification of drilling fluids within a borehole. It has been discovered that solidification may be achieved through the addition of a reactive monomer, or monomers, to a drilling fluid. A polymerization initiator is subsequently added to the drilling fluid containing the reactive monomer and the drilling fluid composition is displaced into a selected location within a borehole and cured.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
By "drilling fluid", as used herein, is meant waterbased drilling mud, including but not limited to, spud mud, natural mud, chemically treated mud, and saltwater mud. Such drilling fluid has continuous and dispersed phases and is substantially hydrocarbon free. The continuous water phase may be fresh water, brackish water, brine water, seawater or other water containing fluid. The dispersed phase may be clay, shale, barite or any other solid conventionally utilized. Additionally, the drilling fluid may contain any of a variety of well known additives and dispersants utilized by those skilled in the art to enhance desired fluid properties. Exemplary additives and dispersants include, but are not limited to, phosphates, lignosulfonates, calcium compounds, quebracho, polymers, copolymers, and various metal salts.
The present invention is based on the discovery that the incorporation of a reactive monomer, or monomers, into a drilling fluid and the subsequent polymerization of the monomer provides a relatively impermeable consolidated body to be formed from the drilling fluid. The resultant solidified mass of drilling fluid can be used in place of the cement utilized in conventional well drilling methods to cement a casing within the borehole.
One type of reactive monomer that may be utilized in the present invention is the metal salt of certain α, β-ethylenically unsaturated carboxylic acids, specifically the metal salts of acrylic and methacrylic acids. The metal component of the unsaturated carboxylic acid metal salt may include, without limitation, magnesium, calcium, iron, sodium, potassium, aluminum, and zinc. The preferred metals are magnesium, calcium, iron, aluminum, and zinc. Zinc is particularly preferred.
The unsaturated carboxylic acid metal salts that may be utilized in the present invention correspond to the general structural formula shown in Formula 1 below: ##STR1## in which R and R' are independently selected from the group consisting of hydrogen, hydroxyl, alkyl, alkenyl, alkynl, aryl, aralkyl, and alkaryl, Me is a metal atom selected from the above-listed metals and n is an integer from 1 to 6.
The preferred metal salts are zinc diacrylate and zinc dimethacrylate. These metal salts are water soluble, or dispersable, and are compatible with the other inorganic components conventionally utilized in drilling fluids. Additionally, both zinc diacrylate and zinc dimethacrylate are advantageous because they may contribute to the high density requirement of drilling fluids and will provide good adhesion between the casing and borehole rock formation surfaces.
In addition to the di(meth)acrylic acid metal salts, the monomethacrylic acid salts of certain metals may be utilized as the reactive monomer in the compositions and methods of the present invention. The preferred monomethacrylate is zinc monomethacrylate. Both the di(meth)acrylic acid metal salts and the monomethacrylic acid metal salts are well known and commercially available.
Still further types of monomers that may be utilized as the reactive monomer in the compositions and methods of the present invention are aromatic acid (meth)acrylates. The aromatic acid (meth)acrylates useful in the present invention contain a high degree of carboxyl, anhydride, and reactive ester functional groups. These aromatic acid (meth)acrylates and their preparation are described in U.S. Pat. Nos. 4,722,947 and 4,745,138 to Thanwalla et al. which are incorporated in their entirety herein by reference. The preferred aromatic acid (meth)acrylate is one of sufficiently high acid number to permit solubility in aqueous alkaline mediums. The aromatic acid (meth)acrylates may additionally function as dispersants to maintain the fluidity of the drilling fluid prior to polymerization of these monomers by the addition of a polymerization initiator.
The reactive monomers may be used singly or in combination. The preferred reactive monomer is zinc diacrylate. The amount of the reactive monomer, or monomers, to be used is a crosslinking-effective amount or, in other words, an amount that is sufficient upon crosslinking to solidify the drilling fluid in situ and secure the drill pipe in its position in the borehole. The lower limit of the amount of reactive monomer that may be used is calculated based on the amount and surface area of the dispersed phase solids and additives in the drilling fluid. The amount must be sufficient to form a solidified drilling fluid mass upon crosslinking. The amount used preferably does not exceed the solubility of the reactive monomer in water. If an amount that exceeds the solubility limit is utilized, no benefit to polymerization will be observed. However, the excess monomer may provide additional benefits, i.e., improved fluid viscosity.
If the reactive monomer utilized is an α, β-ethylenically unsaturated carboxylic acid metal salt, the monomer may be incorporated into the drilling fluid by using the metal salts of the unsaturated carboxylic acid obtained by reacting the metal compound and the unsaturated carboxylic acid. Alternatively, the unsaturated carboxylic acid and the metal compound, i.e., metal oxide, metal hydroxide, metal carbonate and the like may be added into the drilling fluid and reacted to form the metal salts in situ.
Polymerization of the reactive monomer, or monomers, is initiated by the addition of a water soluble polymerization initiator. Any of a variety of the well known water soluble polymerization initiators may be utilized. Examples of such initiators include the redox initiators comprising a reducing agent, such as a sulfite or bisulfite of an alkali metal, ammonium sulfite or ammonium bisulfite, and an initiator, such as an alkali metal or ammonium persulfate or alkali metal or ammonium thiosulfate, in combination with the reducing agent. Alternatively, an alkali metal of persulfate or ammonium persulfate may be used alone as a thermal initiator.
Tertiary alkyl hydroperoxides may also be utilized as polymerization initiators in the compositions and methods of the present invention. Exemplary hydroperoxides include 2,5-dihydroperoxy-2,5-dimethylhexane, tertiarybutyl hydroperoxide, and tertiaryamyl hydroperoxide and cumene hydroperoxide.
Other suitable polymerization initiators useful in the compositions and methods of the invention include azo initiators. Exemplary azo initiators include 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 2,2-azobis(methyl isobutyrate), 2,2'-azobis(N,N'-dimethylene isobutyramidine) dihydorchloride, 2,2'-azobis 2-2(2-imidazolin-2-yl)propane!, 2,2'-azobis 2-methyl-N-(2-hydroxyethyl)-propionamide!, and 1,1'-azobis(cyclohexane-1-carbonitrile).
The initiators can be used singly or in any suitable combination. The amount of initiator used is an amount effective to cure the reactive monomer or monomers. More specifically, the amount of polymerization initiator is calculated as solids, of between 0.1% to 10%, preferably between 0.5% to 5.0% of the weight of the reactive monomer, or monomers. The preferred teritary alkyl hydroperoxide initiator is tertiarybutyl peroxide and the preferred redox initiator is ammonium persulfate/sodium bisulfite.
Any water-based drilling fluid may be utilized in the compositions and methods of the present invention. Exemplary drilling fluids include high lime fluids (about 2.0 to about 15 pounds of excess lime per barrel of drilling fluid), low lime fluids (about 0.5 to about 3.0 pounds of excess lime per barrel of drilling fluid), low lime-salt-alcohol fluid (about 1 to about 3.0 pounds of excess lime, about 18 to about 109 pounds of salt, about 1 to about 158 pounds of alcohol per barrel of drilling fluid), sea-water-lignosulfonate fluids, seawater-gypsum fluids, sodium chloride-partially hydrolyzed polyacrylamide fluids, and fresh water-salt-partially hydrolyzed polyacrylamide fluids. Preferably, lime drilling fluids are utilized because these fluids provide good solidification of the filter cake deposits during recirculation. The non-lime based drilling fluids may be converted to lime-based fluids by the addition of between one to ten pounds of lime per barrel of fluid. A viscosity reducer, in an amount of between one to ten pounds per barrel of fluid, may also be required.
The reactive monomer, or monomers, may be added to the drilling fluid prior to, or during the use of the drilling fluid in recirculation. The polymerization initiator may be added to the drilling fluid containing the reactive monomer or monomers shortly before, during, or following placement of the casing within the borehole. The drilling fluid containing the reactive monomer and polymerization initiator is then pumped into the casing, displaced by conventional methods to a location selected so that the cured drilling fluid composition functions to cement the casing in position, and allowed to cure. The time to cure is dependent on drilling fluid temperature and the polymerization initiator utilized. Generally, the curing time is between five minutes and three days.
Other embodiments of the invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. It is intended that the specification be considered as exemplary only, with the true scope and spirit of the invention being indicated in the following claims. | Drilling fluid composition adapted for solidification in a borehole and method for solidifying a drilling fluid in a borehole are provided. The drilling fluid composition comprises (1) a drilling fluid, (2) a crosslinking-effective amount of at least one reactive monomer wherein the at least one reactive monomer is a metal salt of an α, β-ethylenically unsaturated carboxylic acid, a monomethacrylic acid metal salt, an aromatic acid acrylate, an aromatic acid methacrylate, or mixtures thereof, and (3) a polymerization initiator. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to an electrical termination system. More particularly, it relates to a telephone cable shield bond connector.
Telephone cable, particularly buried cable, often includes a metal shield which provides both mechanical and electrical protection for the primary conductors in the core. This metal shield surrounds the core and is particularly useful in insuring that lightning does not penetrate the core. In order to provide this electrical protection, the shield must be properly grounded. Thus, the shield must be terminated so it may be connected to a ground post, and so that the shields of adjacent cables may be spliced together by a jumper. Obviously, this termination must be very reliable.
A standard technique to terminate a shield is to punch a hole through the polyethylene jacket of the cable and through the shield and insert a threaded stud through the hole with the base of the screw head having serrations for penetrating into the shield. A nut is tightened down onto the stud and on to the polyethylene jacket, thus driving the serrations down into the shield and holding it in place. One of the problems with this type of termination system is that the polyethylene jacket tends to flow, even at relatively low temperatures, as what is known as cold flow. This permits the assembly to loosen, and, therefore, any electrical connection which is made to the assembly becomes unreliable. One such termination system is set forth in U.S. Pat. No. 4,023,882, which also uses a lock washer to secure the screw head.
Another cable shield bond device is disclosed in U.S. Pat. No. 3,857,994. This patent utilizes a rivet having serrations in the base for penetrating into the shield. The top of the rivet barrel is terminated to a rigid dome-shaped member which is further connected to an electrical jumper. The dome-shaped member and the base of the rivet compress a pair of rubber resilient members, which in turn maintain electrical contact between the serrated ring and the shield. The specification does not lead one to believe that the dome-shaped member is itself resilient.
U.S. Pat. No. 3,963,299 also shows a shield bond connector which utilizes a serrated plate for biting into the shield of the cable. A cover plate, which generally conforms to the shape of the cable, is terminated over the top of the cable and, along with a stud and screw combination, holds the serrated pressure plate in place.
In a field somewhat removed from shield bond connectors, U.S. Pat. No. 3,644,869 shows the use of a Belleville washer in an electrical connector assembly. The Belleville washer serves as a spring to provide connection forces.
OBJECTS OF THE INVENTION
It is, therefore, one object of the invention to provide an improved reliable cable shield bond connector.
It is another object to provide a simple and inexpensive means for terminating a cable shield.
It is still another object to provide a shield bond connector which remains terminated in spite of the cold flow problem associated with the cable jacket material.
SUMMARY OF THE INVENTION
In accordance with one form of this invention, there is provided an assembly for terminating a cable shield having a cable connector with a base and tubular throughbore. The base includes serrations for penetrating and bonding to a cable shield. The tubular throughbore is received in a pre-formed hole in the cable shield. A resilient metal dome having a hole therethrough receives the tubular throughbore. A mechanism is provided for compressing the resilient dome and holding the dome in its compressed state while the assembly is terminated to the cable shield for maintaining electrical and mechanical contact between the penetrating serrations and the shield.
In accordance with another form of this invention, there is provided a method for terminating a cable shield by exposing the inside surface of the shield to the outside of the core of the cable. A hole is formed through the shield. The tubular member of a tubular rivet is passed through the hole in the shield so that a portion of the tubular member protrudes to the outside of the cable. Serrations on the base of the tubular rivet contact the shield. The protruding portion of the tubular member is placed through the bore of a Belleville washer. The washer has its concaved surface facing the shield. A threaded stud is passed through the tubular member and the bore in the Belleville washer. A wedge and a nut are attached onto the stud and tightened about the stud so as to swage or bend the top of the tubular member outwardly and onto the convexed side of the Belleville washer, thereby flexing the washer inwardly and driving and holding the serrations into the shield.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is set forth in the appended claims. The invention, however, together with further objects and advantages thereof, may be better understood when taken in conjunction with the following drawings, in which:
FIG. 1 is an exploded view of the termination assembly of the subject invention, including the parts utilized in the method for termination.
FIG. 2 is a cross-sectional view of the connector assembly of FIG. 1 after having been terminated to the shield of the cable.
FIG. 3 is a top view of the termination assembly of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIG. 1, there is provided telephone cable 10, including a core housing a pair of conductors 12 and 14. Cable 10 further includes metal shield 16 and polyethylene jacket 18. The shield and jacket have been peeled away from the core of the cable to form a flattened end section 20 which is adapted to be terminated. In some instances, the inside surface of the shield 16 is coated with a plastic material to prevent corrosion.
The termination system 22 includes connector base 24, which is in the form of a tubular rivet. Tubular rivet 23 includes a tubular member 25 and base member 24, which are integral with one another. A serrated ring 26 is received about tubular member 25, and rides against the top portion 27 of the connector base 24 forming a pressure plate against serrated ring 26. Serrated ring 26 includes a plurality of serrations or teeth 28, which are adapted to pierce the cable shield and make the electrical termination thereto. Alternatively, the connector base itself could have cable shield piercing serrations thereon, thus eliminating the serrating ring. The tubular member of the connector base 24 is adapted to pass through hole 30, which has been pre-formed through the cable jacket and shield by standard hole punch. The tubular member passes through the hole 30 to the extent that the serrated ring rests against the cable shield 16. The tubular member further passes through connector dome 32, which is resilient, and, in this embodiment, is in the form of a Belleville washer.
Mounting bolt 34 may be a standard bolt or a specially designed hand held bolt, as shown in FIG. 1. Mounting bolt 34 includes handle 36 and threaded stud 38, which is adapted to pass through the bore of the tubular member 25, thus protruding through the end portion 40 of the tubular member. A swaging collar 42 passes over the end of stud 38, and the lower outer periphery surface 44 of the swaging collar makes contact with the inner surface 46 of the tubular member.
As can be seen, swaging collar 42 is somewhat conical in shape. Driving nut 48 is threaded and is received over the top and makes contact with the upper surface 50 of the swaging collar, and is mounted on stud 38. Alternatively, the nut and swedging collar could be of a single piece construction. A tool, such as a wrench or nut driver, is adapted to turn nut 48 down the barrel of stud 38 which drives swaging collar 42 into the throat of tubular member 25. Tubular member 40 is bent back as shown in FIGS. 2 and 3, and particularly indicated as ends 50, forming, in most situations, four leaves 52. Leaves 52, having been made through the action of the swaging collar and the bottom portion 54 of the nut, rest against the resilient connector dome 32, riveting or fastening the termination together. Also, as the nut 48 is turned along stud 38, connector base drives the serrations 28 of ring 26 into cable shield 16. Once the nut is turned down slightly and the leaves are formed tightly down on Belleville washer 32, with the concaved surface 56 of the Belleville washer being flexed inwardly into the cable jacket 18, the rivet leaves hold the assembly in place. The Belleville washer, being flexed inwardly, applies constant force on the serrated ring, pressing it into cable shield.
Furthermore, the dome shape of the Belleville washer will hold the polyethylene in the cable jacket 18 in place, thusly eliminating cold flow, because the jacket material is trapped along the edges 58 of the Belleville washer.
FIG. 2 shows the termination system after the termination tools, namely, the bolt 34, swaging collar 42 and nut 48 have been removed. As can be seen, the termination presents a tubular connection through the bore 60 of rivet 23 so that the termination may be connected to a station protector ground stud or a ordinary bolt by simply running the bolt through the bore much like the tool bolt 34 was done. A jumper wire is usually connected to the bolt by an appropriate nut.
As can be seen from FIG. 2, serrations 28 are driven deeply into cable shield 16 to form the electrical contacts. A sealing gel 62 is provided between the top portion of the serrated ring and the core side of the cable shield 16. This sealing gel corrosion at the point of contact of the serrations 28.
Thus, it can be seen that a simplified shield bond termination has been provided having almost no tool expense requirements and using very few piece parts. Furthermore, by using the rivet/Belleville washer resilient technique, it has been found that this termination is much more reliable than the prior art terminations.
From the foregoing description of the illustrative embodiment of this invention, it will be apparent that many modifications may be made therein. It will be understood, therefore, that this embodiment of the invention is intended as an exemplification of the invention only, and that the invention is not limited thereto. It is to be understood that it is intended that the appended claims cover all such modifications that shall fall within the true spirit and scope of the invention. | There is provided a termination assembly for a cable shield which is particularly useful in connecting the shield to ground. The termination includes a tubular rivet for compressing a serrated ring into the shield for making electrical and mechanical termination. A resilient Belleville washer is compressed by the rivet for maintaining the termination. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to a transporting apparatus, and more particularly relates to a transporting apparatus for transporting a rack accommodating specimen containers to a specimen supplying position of a specimen processing apparatus for processing the specimen samples.
BACKGROUND
[0002] Conventional transporting apparatuses for transporting a rack accommodating sample containers to a specimen supplying position of a specimen processing apparatus for processing specimen samples are well known (for example, refer to Japanese Laid-Open Utility Model No. 63-141455). The specimen samples to be processed by the specimen processing apparatus are placed in specimen containers accommodated in a rack.
[0003] In the transporting apparatus disclosed in the -previously mentioned Japanese Laid-Open Utility Model No. 63-141455, a belt is stopped when a sensor detects an edge (detection part) of identical shape provided at a predetermined pitch on a specimen frame (rack) transported by the belt, and the specimen sample in the specimen container accommodated in the rack is mixed and suctioned.
[0004] In the conventional transporting apparatus disclosed in Japanese Utility Model Filing No. 6-770, when the specimen frame (rack) is moved one pitch in a transport direction, or a direction opposite to the transport direction, it is impossible for the sensor to detect the one pitch movement of the specimen frame because the edge (detection part) on the specimen frame has identical shape. In this case, an anomaly in the transporting of the rack is not determined, and a problem arise inasmuch as the transport of the specimen frame (rack) continues, and a different specimen container than the specimen container that is supposed to be analyzed is supplied to the specimen supplying position of the specimen processing apparatus.
SUMMARY
[0005] The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary.
[0006] A first aspect of the transporting apparatus of the present invention provides a transporting apparatus which transports at least one specimen container accommodated in a rack to a specimen supplying position for supplying a specimen processing apparatus, comprising: a transport mechanism configured to transport the at least one specimen container to the specimen supplying position by transporting the rack; and a detection unit for obtaining information specifying the position of the rack being transported by the transport mechanism.
[0007] A second aspect of the transporting apparatus of the present invention provides a transporting apparatus which transports at least one specimen container accommodated in a rack to a specimen supplying position for supplying a specimen processing apparatus, comprising: a transport mechanism configured to transport the at least one specimen container to the specimen supplying position by transporting the rack along a transport path extending in a predetermined direction; and a detection unit for obtaining information representing the position of the rack whenever a rack is transported by the transporting mechanism; wherein the position information at adjacent positions on the transport path are mutually different information.
[0008] A third aspect of the present invention provides a transport system comprising: a transport system comprising: a specimen processing apparatus configured to process specimen samples in a specimen container; a transporting apparatus which transports at least one specimen container accommodated in a rack to a specimen supplying position for supplying the specimen processing apparatus, comprises, a transporting mechanism configured to transport the at least one specimen container to the specimen supplying position by transporting the rack, a detection unit configured to obtain information specifying the position of the rack transported by the transporting mechanism; and a control unit configured to control the operation of the transporting apparatus; wherein the control unit determines whether or not a container accommodated in a rack has been transported to the specimen supplying position based on the position specifying information of the detection unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view showing the transporting apparatus of a first embodiment of the present invention connected to an analyzer;
[0010] FIG. 2 is a perspective view showing the structure of the rack transported by the transporting apparatus of the first embodiment shown in FIG. 1 ;
[0011] FIG. 3 is a frontal view showing the structure of the rack transported by the transporting apparatus of the first embodiment shown in FIG. 1 ;
[0012] FIG. 4 is a perspective view showing the structure of the transporting apparatus of the first embodiment of the present invention;
[0013] FIG. 5 is a plan view showing the structure of the transporting apparatus of the first embodiment of the present invention;
[0014] FIG. 6 is a side view showing the structures on the periphery of the retention regulating mechanism of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0015] FIG. 7 is a plan view showing the structure of a first rack transport mechanism of the transporting apparatus of the first embodiment shown in FIGS. 4 and 5 ;
[0016] FIG. 8 is a side view of the first rack transport mechanism of FIG. 7 ;
[0017] FIG. 9 is a plan view showing the transportation of a rack by the first rack transport mechanism of FIG. 7 in a stopped state;
[0018] FIG. 10 is a side view showing the connecting member of the first rack transport mechanism of FIG. 8 engaged to the rack;
[0019] FIG. 11 is a side view showing the connecting member of the first rack transport mechanism of FIG. 8 engaged to the rack;
[0020] FIG. 12 is a side view showing the structures on the periphery of a return prevention member of the transporting apparatus of the first embodiment shown in FIGS. 4 and 5 ;
[0021] FIG. 13 is a side view showing the return prevention member of FIG. 12 in the rotating state;
[0022] FIG. 14 is a side view showing the structures on the periphery of the retention regulating mechanism of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0023] FIG. 15 is a side view showing the retention regulating member of the retention regulating mechanism of FIG. 14 protruding from the installation surface of the retention plate;
[0024] FIG. 16 is a plan view showing the structure of the horizontal feeding unit of the transporting apparatus of the first embodiment shown in FIGS. 4 and 5 ;
[0025] FIG. 17 is a side view of the horizontal feeding unit of FIG. 16 ;
[0026] FIG. 18 is a side view showing the connecting member of the horizontal feeding unit of FIG. 17 engaged to the rack;
[0027] FIG. 19 is a side view showing the connecting member of the horizontal feeding unit of FIG. 17 engaged to the rack;
[0028] FIG. 20 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0029] FIG. 21 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0030] FIG. 22 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0031] FIG. 23 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0032] FIG. 24 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0033] FIG. 25 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0034] FIG. 26 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0035] FIG. 27 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0036] FIG. 28 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0037] FIG. 29 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0038] FIG. 30 is a schematic view illustrating the transport operation of the horizontal feeding unit of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0039] FIG. 31 is a schematic view illustrating the transport operation of the horizontal feeding unit of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0040] FIG. 32 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0041] FIG. 33 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0042] FIG. 34 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0043] FIG. 35 is a schematic view illustrating the transport operation of the horizontal feeding unit of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0044] FIG. 36 is a schematic view illustrating the transport operation of the horizontal feeding unit of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0045] FIG. 37 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0046] FIG. 38 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0047] FIG. 39 is a schematic view illustrating the transport operation of the transporting apparatus of the first embodiment of FIGS. 4 and 5 ;
[0048] FIG. 40 is a plan view showing the structure of the transporting apparatus of a second embodiment of the present invention;
[0049] FIG. 41 is a plan view showing the structure of a first rack transport mechanism of the transporting apparatus of the second embodiment shown in FIG. 40 ;
[0050] FIG. 42 is a side view of the first rack transport mechanism of FIG. 41 ;
[0051] FIG. 43 is a schematic view illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention;
[0052] FIG. 44 is a schematic view illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention;
[0053] FIG. 45 is a schematic view illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention;
[0054] FIG. 46 is a schematic view illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention;
[0055] FIG. 47 is a schematic view illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention; and
[0056] FIG. 48 is a schematic view showing the transport controller of the first embodiment of the present invention connected to an analyzer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0057] The embodiments of the present invention are described below based on the drawings.
First Embodiment
[0058] FIG. 1 is a perspective view showing the transporting apparatus of a first embodiment of the present invention connected to an analyzer. FIGS. 2 and 3 are respectively a perspective view and frontal view showing the structure of the rack transported by the transporting apparatus of the first embodiment of FIG. 1 . FIG. 48 is a schematic view showing the transport controller of the first embodiment of the present invention connected to an analyzer. The overall structure, which includes a first blood analyzer 2 and a second blood analyzer 3 connected to the transporting apparatus of the first embodiment is described hereinafter with reference to FIGS. 1 through 3 .
[0059] The transporting apparatus of the first embodiment is, for example, connected to a first blood analyzer 2 for performing primary analysis, and a second blood analyzer 3 for performing secondary analysis, as shown in FIG. 1 . The primary analysis performed by the first blood analyzer 2 is performed on all specimen samples, and the secondary analysis performed by the second blood analyzer 3 is performed on only those specimen samples that are determined to require detailed analysis based on the results of the primary analysis.
[0060] A specimen sample is placed in a specimen container 4 , and the specimen container 4 is placed in a rack 5 . The rack 5 is constructed so as to accommodate ten specimen containers 4 , as shown in FIGS. 2 and 3 . The rack 5 has a bottom part 5 a that has a length in the foreground direction that is greater than the part accommodating the specimen containers 4 . Empty regions are provided on the back surface side of the rack 5 , and a plurality of partitions 5 b are provided in the empty regions on the back surface side of the rack 5 . Furthermore, a plurality of channels 5 c are provided on the side surface side of the part of the rack 5 accommodating the specimen containers 4 .
[0061] As shown in FIG. 1 , a transporting apparatus 1 has the function of transporting a rack 5 accommodating specimen containers 4 to the respective specimen supplying positions 2 a and 3 a of the first blood analyzer 2 and the second blood analyzer 3 . The specimen supplying position 2 a of the first blood analyzer 2 is provided with a hand member 2 b , for taking the specimen container 4 from the rack 5 and mixing the specimen sample in the specimen container 4 and supplying the specimen sample into the first blood analyzer 2 . The specimen supplying position 3 a of the second blood analyzer 3 is also provided with a hand member 3 b , for taking the specimen container 4 from the rack 5 and mixing the specimen sample in the specimen container 4 and supplying the specimen sample into the second blood analyzer 3 . Barcode readers 2 c and 3 c for reading barcodes adhered to the specimen containers 4 are respectively provided at positions forward of the transported rack 5 at the specimen supplying position 2 a of the first blood analyzer 2 and specimen supplying position 3 a of the second blood analyzer 3 .
[0062] Specimen container rotation devices 6 for rotating the specimen containers 4 accommodated in the rack 5 are respectively provided in the region corresponding to the position toward the viewer to which the rack 5 is transported at the specimen supplying positions 2 a and 3 a of the transporting apparatus 1 . The reading of the barcode adhered to the specimen container 4 by the barcode readers 2 c and 3 c is accomplished when the specimen container rotation device 6 rotates the specimen container 4 .
[0063] The two transporting apparatuses 1 , which are respectively connected to the first blood analyzer 2 and second blood analyzer 3 , are connected through an intermediate transporting apparatus 7 . The two transporting apparatuses 1 , which are respectively connected to the first blood analyzer 2 and second blood analyzer 3 , have identical structures.
[0064] As shown in FIG. 48 , the first blood analyzer 2 is provided with a control unit 2 d , the second blood analyzer 3 is provided with a control unit 3 d , and the transport controller 91 (personal computer) is provided with a control unit 91 d . The control unit 91 d is connected to the control unit 2 d and control unit 3 d , respectively, by landline or wireless connection so as to be capable of communication. The transport controller 91 is connected to the transporting apparatus 1 so as to control the operation of the transporting apparatus 1 (not shown in the drawing). The control unit 91 d of the transport controller 91 determines whether or not a specimen container 4 in the rack 5 has arrived at the specimen supplying position 2 a or 3 a of the transporting apparatus 1 based on signals from a detection unit 34 for detecting the transport position of the rack 5 conveyed by the transporting apparatus 1 described later. The control unit 91 d commands the control unit 2 d or the control unit 3 d so as to bring the specimen container 4 arrived at the specimen supplying position 2 a or 3 a of the transporting apparatus 1 to the first blood analyzer 2 or the second blood analyzer 3 when the control unit 91 d determines the presence of the specimen container 4 in the rack 5 arrived at the specimen supplying position 2 a or 3 a of the transporting apparatus 1 .
[0065] FIGS. 4 and 5 are a perspective view and plan view, respectively, showing the structure of the transporting apparatus of a first embodiment of the present invention. FIGS. 6 through 19 are detailed drawings showing the structure of the transport apparatus of the first embodiment of FIGS. 4 and 5 . The structure of the transporting apparatus 1 of the first embodiment is described in detail below with reference to FIGS. 4 through 19 .
[0066] The transporting apparatus 1 of the first embodiment includes an input delivery unit 10 , retention unit 20 , horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 , as shown in FIGS. 4 and 5 .
[0067] The input delivery unit 10 of the transporting apparatus 1 is provided to deliver a rack 5 , which has been introduced from the entrance 1 a of the transporting apparatus 1 , to the retention unit 20 side after being moved in the X 1 direction. The input delivery unit 10 includes a rack take-in mechanism 11 , and rack take-out mechanism 12 .
[0068] The rack take-in mechanism 11 of the transporting apparatus 1 is provided to move a rack 5 , which has been introduced from the entrance 1 a , in the X 1 direction. The rack take-in mechanism 11 is configured by a conveyor belt 111 , pulleys 112 a and 112 b , motor 113 , detection unit 114 , and transmission-type sensor 115 . The conveyor belt 111 is installed on the pulleys 112 a and 112 b , and the pulley 112 a is linked to the motor 113 . Thus, the conveyor belt 111 is driven through the pulley 112 a by driving the motor 113 . Accordingly, when a rack 5 is introduced from the entrance la, the rack 5 is moved in the X 1 direction by driving the conveyor belt 111 in the X 1 direction.
[0069] The detection unit 114 of the rack take-in mechanism 11 is provided to detect the arrival of a rack 5 , which is being moved in the X 1 direction by the conveyor belt 14 , at a take-out position P 1 . The take-out position P 1 is a position at which the rack 5 can be moved to the retention unit 20 side by the rack take-out mechanism 12 . The detection unit 114 has a detection pin 114 a , compression spring 114 b , and transmission-type sensor 114 c . A force is exerted by the compression spring 114 b on one end of the detection pin 114 a , such that the detection pin 114 a projects to the take-out position P 1 side. The transmission-type sensor 114 c is disposed at the other end of the detection pin 114 a . When a rack 5 is transported to the takeout position P 1 by the conveyor belt 111 , the projecting end of the detection pin 114 a is pressed by the rack 5 , such that the detection pin 114 a is moved in the X 1 direction against the force exerted by the compression spring 114 b . Thus, since the other end of the detection pin 114 a blocks the transmission-type sensor 114 c , the arrival of the rack 5 being conveyed by the conveyor belt 111 in the X 1 direction at the take-out position P 1 can be detected.
[0070] The transmission-type sensor 115 of the rack take-in mechanism 11 is provided to detect the presence/absence of a rack 5 at the take-out position P 1 , and detect when a rack 5 has been taken out from the takeout position P 1 to the retention unit 20 side by the rack take-out mechanism 12 . The transmission-type sensor 115 is disposed so as to be blocked when a rack 5 is present at the takeout position P 1 .
[0071] The rack take-out mechanism 12 of the input delivery unit 10 is provided to take a rack 5 , which has been transported to the take-out position P 1 , to the retention unit 20 side. The rack take-out mechanism 12 is configured by a takeout member 121 direct-acting guide 122 , arm 123 , and motor 124 . The takeout member 121 is mounted on the direct-acting guide 122 , and the direct-acting guide 122 is arranged so as to extend in the Y 1 direction (Y 2 direction). A slot 123 a is formed at one end of the arm 123 . This end of the arm 123 is mounted on the take-out member 121 through the slot 123 a , and the other end of the arm 123 is linked to the rotating shaft of the motor 124 . Thus, one end of the arm 123 is rotated by the drive of the motor 124 , such that the take-out member 121 is moved in the direction (Y 1 direction) of extension of the direct-acting guide 122 . Accordingly, when a rack 5 is present at the take-out position P 1 , the rack 5 is moved to the retention unit 20 side by the take-out member 121 .
[0072] The retention unit 20 of the transporting apparatus 1 is provided to retain the rack 5 that has been transported from the entrance la to the specimen supplying position 2 a ( 3 a ). In the first embodiment, the retention unit 20 has the function of again retaining a rack 5 , which has been moved from the specimen supplying position 2 a ( 3 a ) in a direction opposite of the transport direction to repeat an analysis. The retention unit 20 includes a retention plate 21 , first rack transport mechanism 22 , transmission-type sensors 23 and 24 , return prevention member 25 , retention regulating mechanism 26 , and barcode reader 27 .
[0073] The retention plate 21 of the retention unit 20 has a rack contact part 21 a , retention regulating unit 21 b , a pair of hole s 21 c and a pair of holes 21 d , and a notch 21 e . The rack contact part 21 a is provided on the retention plate on the opposite side relative to the input delivery unit 10 . The rack contact part 21 a is formed by bending the retention plate 21 at a right angle relative to the installation surface 21 f. The region between the rack contact part 21 a and the end (return prevention member 25 ) of the retention plate 21 on the input delivery unit 10 side is the retention region for retaining a rack 5 . One part of the region the size of a rack 5 on the input delivery unit 10 side of the retention plate 21 is a rack receiving position P 2 for receiving a rack 5 that has been moved from the input delivery unit 10 . One part of the region the size of a rack 5 on the rack contact part 21 a side of the retention plate 21 is a horizontal feed start position P 3 for starting the transport of a rack 5 by the horizontal feeding unit 30 .
[0074] The retention regulating unit 21 b of the retention plate 21 is formed by bending a predetermined region of the rack contact part 21 a parallel to the installation surface 21 f. That is, the retention regulating member 21 b is formed so as to project from the rack contact part 21 a to the horizontal feed start position P 3 in a planar view. The retention regulating member 21 b is provided to prevent the rack from being placed at the horizontal feed start position P 3 by an operator. Furthermore, the distance from the installation surface 21 f of the retention regulating unit 21 b is set so as to be less than the entire height of the rack 5 , and greater than the height of the bottom part 5 a of the rack 5 , as shown in FIG. 6 . The amount of projection of the retention regulating member 21 b from the rack contact part 21 a is set such that the rack 5 does not come into contact with the retention regulating member 21 b when the rack 5 (bottom part 5 a ) abuts the rack contact part 21 a.
[0075] As shown in FIGS. 4 and 5 , the pair of holes 21 c of the retention plate 21 are formed so as to extend from the rack receiving position P 2 of the retention plate 21 to the horizontal feed starting position P 3 . The pair of holes 21 d of the retention plate 21 are formed as rectangular slots so as to have a length in the lengthwise direction that actually matches the length of the rack 5 (bottom part 5 a ) in the forward direction. The pair of holes 21 d of the retention plate 20 are arranged in a region separated from the rack contact part 21 by an actual distance equal to the length of the rack 5 (bottom part 5 a ) in the forward direction, so as to sandwich the pair of holes 21 c therebetween. The region in which the pair of holes 21 s are formed in the retention plate 21 is the region for regulating the retention of the rack 5 (retention regulating position P 4 ). Furthermore, the pair of notches 21 e of the retention plate 21 are formed at the end of the retention plate 21 on the input delivery unit 10 side.
[0076] In the first embodiment, the first rack transport mechanism 22 of the retention unit 20 has the function of moving a rack 5 that is retained at the installation surface 21 f of the retention plate 21 from the horizontal feed start position P 3 in a direction opposite to the transport direction to the rack receiving position P 2 (Y 2 direction), in addition to the function of moving the rack 5 retained at the installation surface 21 f of the retention plate 21 from the rack receiving position P 2 side to the horizontal feed start position P 3 (Y 1 direction). The first rack transport mechanism 22 is configured by a drive unit 22 a and a rack transport unit 22 b , as shown in FIGS. 7 and 8 . The drive unit 22 a is provided to move the rack transport unit 22 b in the Y 1 direction (transport direction) and Y 2 direction (direction opposite the transport direction), and is disposed below the installation surface 21 f of the retention plate 21 . The drive unit 21 a has a motor 221 , intermediate belt 222 , motor pulley 223 , large diameter pulley 224 , drive belt 225 , pulleys 226 a and 226 b , tension pulley 227 , and direct-acting guide 228 . The intermediate belt 222 is installed on the motor pulley 223 and the large diameter pulley 224 , and the motor pulley 223 is linked to the motor 221 . The drive belt 225 is installed on the pulleys 226 a and 226 b , and the small diameter part 224 a of the large diameter pulley 224 . A tension force is exerted on the drive belt 225 by the tension pulley 227 . Thus, the drive belt 225 is driven by the drive of the motor 221 at reduced speed through the intermediate belt 222 , motor pulley 223 and large diameter pulley 224 . The direct-acting guide 228 is disposed so as to extend in the Yl direction (Y 2 direction).
[0077] The rack transport unit 22 b of the first rack transport mechanism 22 is provided to move a rack 5 , which is retained at the installation surface 21 f of the retention plate 21 , in the Y 1 direction and Y 2 direction. The rack transport unit 22 includes a first moving member 229 , and a second moving member 230 . The first moving member 229 is linked to the drive belt 225 , and the second moving member 230 is mounted on the direct-acting guide 228 . The second moving member 230 has a pair of plates 230 a arranged so as to be mutually opposite with a predetermined distance therebetween, and the first moving member 229 is disposed between the pair of plates 230 a of the second moving member 230 . The second moving member 230 is configured so as to track the movement of the first moving member 229 when the first moving member 229 is moved by the actuation of the drive belt 225 .
[0078] Specifically, a shaft 231 is mounted between the pair of plates 230 a of the second moving member 230 , and the first moving member 229 is inserted on the shaft 231 so as to be slidably in the direction of extension of the shaft 231 (Y 1 direction and Y 2 direction). A compression spring 232 is installed on the shaft 231 to exert a force in the Y 2 direction on the first moving member 229 . Thus, when the first moving member 229 is moved in the Y 1 direction by the drive belt 225 (when the first moving member 229 is moved from the position of FIG. 7 to the position of FIG. 9 ), the first moving member 229 presses one plate 230 a of the second moving member 230 in the Y 1 direction through the compression spring 232 , such that the second moving member 230 is moved in the Y 1 direction along the direct-acting guide 228 , as shown in FIGS. 7 through 9 . When the first moving member 229 is moved in the Y 2 direction by the drive belt 225 (when the first moving member 229 is moved from the position of FIG. 9 to the position of FIG. 7 ), the first moving member 229 presses the other plate 230 a of the second moving member 230 in the Y 2 direction, such that the second moving member 230 is moved in the Y 2 direction along the direct-acting guide 228 .
[0079] As shown in FIGS. 7 and 8 , a cylinder 233 and direct-acting guide 234 are mounted on the second moving member 230 of the rack transport unit 22 b . The cylinder 233 is arranged so as to extend in a perpendicular direction (Z direction) relative to the installation surface 21 f of the retention plate 21 , and the direct-acting guide 234 extends in the Z direction. Furthermore, a shaft holder 235 is mounted on a cylinder rod 233 a and direct-acting guide 234 . Thus, the shaft holder 235 is moved in the direction (Z direction) of the extension of the direct-acting guide 234 by the cylinder rod 233 a extending in the Z direction.
[0080] A shaft 236 is mounted on the shaft holder 235 of the rack transport unit 22 b , and a pair of connectors 237 a and a pair of connectors 237 b are mounted on the shaft 236 so as to be pivotable on the shaft 236 . One of the pair of connectors 237 a is placed at one end of the shaft 236 , and the other of the pair of connectors 237 a is placed at the other end of the shaft 236 . One of the pair of connectors 237 b are placed at one end of the shaft 236 , and the other of the pair of connectors 237 b is placed at the other end of the shaft 236 . The connectors 237 a and 237 b project from the installation surface 21 f through the pair of holes 23 c of the retention plate 21 when the shaft holder 235 is moved in the Z direction, as shown in FIGS. 10 and 11 . The connectors 237 a and 237 b respectively have connecting surfaces 237 c and 237 d for engaging the interior surface of the bottom part 5 a of the rack 5 . Thus, the connectors 237 a and 237 b project from the installation surface 21 f , and when the rack transport unit 22 b is moved in the Y 1 direction (Y 2 direction), the rack 5 is moved in the Y 1 direction (Y 2 direction) by the engagement of the interior surface of the bottom part 5 a of the rack 5 with the connecting surface 237 c ( 237 d ) of the connector 237 a ( 237 b ). As shown in FIG. 10 , the connector 237 a engages the interior surface of the bottom part 5 a of the rack 5 when the rack 5 is moved in the Y 1 direction, and the connector 237 b engages the interior surface of the bottom part 5 a of the rack 5 when the rack 5 is moved in the Y 2 direction, as shown in FIG. 11 .
[0081] As shown in FIGS. 10 and 11 , the connector 237 a of the rack transport unit 22 b , receive a force exerted by the tension spring 238 a mounted on the shaft holder 235 , such that the connector 237 a is brought into parallel with the connecting surface 237 c and interior surface of the bottom part 5 a of the rack 5 . The connector 237 b receives a force exerted by a tension spring 238 b mounted on the shaft holder 235 so as to be brought into parallel with the connecting surface 237 b and interior surface 5 a of the rack 5 . Therefore, when an external force is added from above to the connector 237 a ( 237 b ), the connector 237 a ( 237 b ) is rotated in a predetermined direction against the force exerted by the tension spring 238 a ( 238 b ). Moreover, when the external force from above is eliminated on the connector 237 a ( 237 b ), the connector 237 a ( 237 b ) is rotated in the opposite direction to the predetermined direction by the force exerted by the tension spring 238 a ( 238 b ) and is brought into parallel with the connecting surface 237 c ( 237 d ) and the interior surface of the bottom part 5 a of the rack 5 .
[0082] As shown in FIGS. 7 and 8 , a detection piece 239 is mounted on the first moving member 229 of the rack transport unit 22 b , and a transmission-type sensor 240 is mounted on the second moving member 230 . The detection piece 239 and the transmission-type sensor 230 are provided to detect a stoppage during the transport of the rack 5 in the Y 1 direction by the first rack transport mechanism 22 . Specifically, the detection piece 239 and transmission-type sensor 240 are arranged such that the detection piece 239 blocks the light of the transmission sensor 240 when the second moving member 230 is stationary and the first moving member 229 is moved in the Y 1 direction, as shown in FIG. 9 .
[0083] As shown in FIGS. 4 and 5 , the transmission-type sensor 23 of the retention unit 20 is provided to detect the presence/absence of a rack 5 in the retention region outside the horizontal feed starting position P 3 of the retention unit 20 . The transmission-type sensor 23 is arranged so as to block the light when at least one rack 5 is retained in the retention region outside the horizontal feed starting position P 3 of the retention unit 20 . The transmission-type sensor 24 of the retention unit 20 is provided to detect the arrival of a rack 5 , which is moved from the rack receiving position P 2 side, at the horizontal feed starting position P 3 . The transmission-type sensor 24 is arranged so as to block the light when a rack 5 has arrived at the horizontal feed start position P 3 .
[0084] The return prevention member 25 of the retention unit 20 is provided to prevent a rack 5 , which has been taken from the take-out position P 1 and placed at the rack receiving position P 2 , from being returned from the rack receiving position P 2 to the take-out position P 1 . The return preventing member 25 is disposed in a region corresponding to the notch 21 e of the retention plate 21 . The return prevention member 25 has a perpendicular surface 25 a that is perpendicular to the installation surface 21 f of the retention plate 21 , and an inclined surface 25 b that is inclined at a predetermined angle relative to the perpendicular surface 25 a , as shown in FIG. 12 . As shown in FIGS. 12 and 13 , when a rack 5 is passing the boundary of the take-out position P 1 and the rack receiving position P 2 , the return prevention member 25 rotates downward from the retention plate 21 , and rotates upward from the retention plate 21 to return to the initial condition (condition shown in FIG. 12 ) when the rack 5 has passed the boundary of the take-out position P 1 and the rack receiving position P 2 . The return prevention member 25 does not rotate relative to an external force in the Y 2 direction.
[0085] As shown in FIGS. 4 and 5 , the retention regulating mechanism 26 of the retention unit 20 is provided to regulate the retention of a rack 5 to the retention regulating position P 4 of the retention plate 21 . The retention regulating mechanism 26 is configured by a pair of retention regulating members 261 , and a pair of cylinders 262 , as shown in FIGS. 5 and 14 . The cylinder 262 is arranged so that the cylinder rod 262 a extends in a perpendicular direction (Z direction) relative to the installation surface 21 f of the retention plate 21 . The cylinder rod 262 a is mounted to the surface of the retention plate 21 on the side opposite the installation surface 21 f . Therefore, the body of the cylinder 262 moves in the Z direction toward the retention plate 21 when the cylinder rod 262 a is extended in the Z direction, as shown in FIG. 15 .
[0086] The retention regulating member 261 is mounted on the body of the cylinder 262 on the side opposite the cylinder rod 262 a . The retention regulating member 261 is arranged so as to project from the installation surface 21 f through the hole 21 d of the retention plate 21 when the body of the cylinder 262 is moved in the Z direction. As shown in FIG. 5 , the retention regulating member 262 is formed in a rectangular shape from a planar view, similar to the hole 21 d of the retention plate 21 , and has a length in the length direction that is substantially the same as the length of the rack 5 (bottom part 5 a ) in the forward direction. Therefore, when the retention regulating member 261 projects from the installation surface 21 f , the retention of the rack 5 toward the retention regulating position P 4 is regulated by the retention regulating member 261 , as shown in FIG. 15 . Moreover, when the retention regulating member 261 projects from the installation surface 21 f , the distance between the end of the retention regulating member 261 on the horizontal feed starting position P 3 side and the end of the retention plate 21 on the horizontal feed starting position P 3 side is less than the length of the rack 5 (bottom part 5 a ) in the forward direction, such that the retention of the rack 5 toward the horizontal feed starting position is also regulated.
[0087] As shown in FIGS. 4 and 5 , the barcode reader 27 of the retention unit 20 is provided to read the barcode of a rack 5 moving from the rack receiving position P 2 side to the horizontal feed starting position P 3 side.
[0088] In the first embodiment, the horizontal feeding unit 30 of the transport apparatus 1 is provided to move a rack 5 , which has been transported to the horizontal feed starting position P 3 , to the specimen supplying position 2 a ( 3 a ) and the discharge unit 40 . The horizontal feeding unit 30 is configured so as to transport a rack 5 a distance of approximately 20 mm (the distance between adjacent specimen containers 4 accommodated in the rack 5 ). In the first embodiment, the horizontal feeding unit 30 is configured so as to move a rack 5 , which has been transported to the discharge unit 40 side, in the reverse direction to the transport direction to the horizontal feed starting position P 3 when performing a repeat analysis. The horizontal feeding unit 30 includes a horizontal feed plate 31 , drive unit 32 , rack transport unit 33 , and detection unit 34 , as shown in FIGS. 16 and 17 .
[0089] A hole 31 b extending from the horizontal feed starting position P 3 to a discharge starting position P 5 described later is formed in the transport surface 31 a of the horizontal feed plate 31 of the horizontal feeding unit 30 .
[0090] As shown in FIGS. 16 and 17 , the drive unit 32 of the horizontal feeding unit 30 is provided to move the rack transport unit 33 in the X 1 direction (transport direction) and X 2 direction (direction opposite of the transport direction), and is disposed below the transport surface 31 a of the horizontal feed plate 31 . The drive unit 32 is configured by a motor 321 , drive belt 322 , pulleys 323 a and 323 b , and a direct-acting guide 324 . The motor 321 is linked to the pulley 323 a , and the drive belt 322 is installed on the pulleys 323 a and 323 b . Thus, the drive belt 322 is driven by the actuation of the motor 321 through the pulley 323 a . The direct-acting guide 324 is arranged so as to extend in the X 1 direction (X 2 direction).
[0091] In the first embodiment, the rack transport unit 33 of the horizontal feeding unit 30 has the function of moving the rack 5 from the discharge starting position P 5 to the horizontal feed starting position P 3 (X 2 direction) in addition to the function of moving the rack 5 on the transport surface 31 a of the horizontal feed plate 31 from the horizontal feed starting position P 3 to the discharge starting position P 5 (X 1 direction), as shown in FIGS. 4 and 5 . In the horizontal feeding unit 30 , the initial position 30 a in FIG. 5 is a position where the horizontal feeding of the rack 5 begins by the rack transport unit 33 , and the horizontal feed ending position 30 b in FIG. 5 is the position where the horizontal feeding of the rack 5 ends by the rack transport unit 33 . The rack transport unit 33 is configured by a moving member 331 , solenoid 332 , direct-acting guide 333 , connector 334 , and transmission-type sensor 335 , as shown in FIGS. 16 and 17 . The moving member 331 is mounted on the direct-acting guide 324 and is linked to the drive belt 322 . Thus, the moving member 331 is moved in the direction of the extension of the direct-acting guide 324 (X 1 direction and X 2 direction) by the actuation of the drive belt 322 . The solenoid 332 is mounted on the moving member 331 , and is arranged such that the rod 332 a of the solenoid 332 extends in a direction (Z direction) perpendicular to the transport surface 31 a of the horizontal feed plate 31 . The direct-acting guide 333 is mounted on the moving member 331 , and extends in the Z direction. The connector 334 is mounted on the direct-acting guide 333 and the rod 322 a of the solenoid 322 . Thus, the connector 334 moves in the direction of extension (Z direction) of the direct-acting guide 333 when the rod 322 a of the solenoid 322 is extended in the Z direction.
[0092] In the first embodiment, a first connector 334 a and second connector 334 b are integratedly provided as a unit on the connector 334 of the rack transport unit 33 . The first connector 334 a and the second connector 334 b are disposed so as to project from the transport surface 31 a through the holes 31 b of the horizontal feed plate 31 when the connector 334 is moved in the Z direction, as shown in FIGS. 18 and 19 . Thus, as shown in FIG. 18 , the first connector 334 a and the second connector 334 b project from the transport surface 31 a , and when the rack transport unit 33 is moved in the X 1 direction, the rack 5 is moved in the X 1 direction by the engagement of the interior surface of the rack 5 on the first specimen container 4 side to the first connector 334 a . As shown in FIG. 19 , the plate 5 b of the rack 5 on the tenth specimen container 4 side engages the second connector 334 b , and two racks 5 are simultaneously moved in series in the X 1 direction by the engagement of the interior surface of the rack 5 on the first specimen container 4 side to the first connector 334 a . FIGS. 18 and 19 show racks 5 being moved in the X 1 direction. That is, in FIG. 18 , the first connector 334 a engages the plate 5 b of the rack 5 on the first specimen container 4 side when the rack 5 is moved in the X 2 direction. Furthermore, in FIG. 19 , the second connector 334 b engages the rack 5 on the tenth specimen container 4 side when the rack 5 is moved in the X 2 direction and the first connector 334 a engages the plate 5 b of the rack 5 on the first specimen container 4 side.
[0093] As shown in FIGS. 16 and 17 , the transmission-type sensor 335 of the rack transport unit 33 is provided to detect the projection of the first connector 334 a and the second connector 334 b from the transport surface 31 a of the horizontal feed plate 31 . The transmission-type sensor 335 is arranged such that the light is blocked by the detection piece 334 c mounted on the connector 334 when the first connector 334 a and the second connector 334 b project from the transport surface 31 a of the horizontal feed plate 31 .
[0094] The detection unit 34 of the horizontal feeding unit 30 is provided to detect the position of the rack transport unit moving in the X 1 direction and X 2 direction. The detection unit 34 is configured by transmission-type sensors 341 a and 341 b , and a detection panel 343 . The transmission-type sensor 341 a is provided to detect a rack transport unit 33 that has been moved to the initial position 30 a (refer to FIG. 5 ). The transmission-type sensor 341 a is arranged such that the light is blocked by the detection piece 331 a of the moving member 331 of the rack transport unit 33 when the rack transport unit 33 has been moved to the initial position 30 a . The transmission-type sensor 341 b is provided to detect a rack transport unit 33 that has been moved to horizontal feed end position 30 b (refer to FIG. 5 ). The transmission-type sensor 341 b is arranged such that light is blocked by a detection piece (not shown in the drawing) of the moving member 331 of the rack transport unit 33 when the rack transport unit 33 has been moved to the horizontal feed end position 30 b.
[0095] In the first embodiment, the transmission-type sensors 342 a and 342 b of the detection unit 34 are provided to detect the transport position of the rack 5 . The transmission-type sensors 342 a and 342 b are mounted on the moving member 331 of the rack moving member 33 . The light-emitting unit and light-receiving unit of the transmission-type sensors 342 a and 342 b are arranged so as to confront one another with the detection panel 343 disposed therebetween. The transmission-type sensors 342 a and 342 b are disposed so as to be separated by a predetermined distance in the movement direction (X 1 direction and X 2 direction) of the rack transport unit 33 . In the first embodiment, the detection panel 343 of the detection unit 34 has a plurality of square-shape detection holes 343 a through 343 h arrayed in the movement direction (X 1 direction and X 2 direction) of the rack transport unit 33 . The detection holes 343 a through 343 h are provided to change the transmission-type sensors 342 a and 342 b to the transmit (ON) state or block (OFF) state. The detection holes 343 a through 343 h are further arranged to change the state of at least one of the transmission-type sensors 342 a and 342 b (ON state and OFF state) whenever the rack transport untit 33 is moved one pitch in the X 1 direction as the rack transport movement 33 is moved at the approximate 20 mm pitch in the X 1 position. Thus, the combinations of the ON state and OFF state of the transmission-type sensors 342 a and 342 b is changed each time the rack transport unit 33 is moved one pitch in the X 1 direction. That is, the position of the rack transport unit 33 is detected by the combination of ON state and OFF state of the transmission-type sensors 342 a and 342 b.
[0096] When the transmission-type sensor 342 a is positioned in the region corresponding to the detection hole 343 a in the detection unit 34 , the rack transport unit 33 is moved to the initial position 30 a (refer to FIG. 5 ). When the transmission-type sensor 342 a is position in the region corresponding to the detection hole 343 g , the rack transport unit 33 is moved to the horizontal feed ending position 30 b (refer to FIG. 5 ). The detection holes 343 a through 343 g are arranged sequentially in the X 1 direction (from the initial position 30 a to the horizontal feed ending position 30 b ). The detection hole 343 h is separated by a predetermined distance in the X 2 direction from the detection hole 343 a.
[0097] As shown in FIGS. 4 and 5 , the discharge unit 40 of the transporting apparatus 1 is provided to transport the a rack 5 , which has been moved from the horizontal feeding unit 30 to the discharge unit 490 , to a position from which the rack 5 can be delivered from an output opening 1 b by a transport unit 50 . The discharge unit 40 includes a discharge plate 41 , second rack transport mechanism 42 , and transmission-type sensors 43 and 44 .
[0098] The discharge plate 41 of the discharge unit 40 has a rack contact part 41 a , and a pair of holes 41 b . A region of the size of a single rack 5 on the horizontal feeding unit 30 side of the discharge plate 41 is the discharge starting position P 5 for starting the transport of a rack 5 in the discharge unit 40 . A region of the size of a single rack 5 on the side of the discharge plate 41 opposite the discharge starting position P 5 is output starting position P 6 for starting the transport of a rack 5 from the output opening 1 b by the transport unit 50 . The rack contact part 41 a is provided on the output starting position P 6 side of the discharge plate 41 . The rack contact part 41 a is formed by bending the discharge plate 41 in a direction perpendicular to the discharge surface 41 c . The pair of holes 41 b of the discharge plate 41 are formed in the discharge plate 41 and extend from the discharge starting position P 5 to the output starting position P 6 .
[0099] A second rack transport mechanism 42 of the discharge unit 40 is provided to move a rack 5 on the discharge surface 41 c of the discharge plate 41 in the Y 2 direction, and is provided below the discharge surface 41 c of the discharge plate 41 . The second rack transport mechanism 42 has a pair of connectors 421 that engage the interior surface of the bottom part 5 a of the rack 5 when the rack 5 is moved in the Y 2 direction. The connectors 421 are disposed in a region corresponding to the holes 41 b of the discharge plate 41 , and are movable in the Y 2 direction (Y 1 direction) in the holes 41 b by the drive unit of the rack transport mechanism 42 not shown in the drawing. The connectors 421 are configured so as to project from the discharge surface 41 c through the holes 41 b of the discharge plate 41 when the rack 5 is moved in the Y 2 direction.
[0100] The transmission-type sensor 43 of the discharge unit 40 is provided to detect the arrival of a rack 5 , which is moving from the horizontal feeding unit 30 in the X 1 direction, at the discharge starting position P 5 . The transmission-type sensor 43 is disposed such that the light is blocked when the rack 5 arrives at the discharge starting position P 5 . The transmission-type sensor 44 of the discharge unit 40 is provided to detect the arrival of a rack 5 , which is moving from the discharge starting position P 5 in the Y 2 direction, at the output starting position P 6 . The transmission-type sensor 44 is disposed such that the light is blocked when the rack 5 arrives at the output starting position P 6 .
[0101] The output delivery unit 50 is provided to transport a rack 5 , which has been moved to the output starting position P 6 in the discharge unit 40 , from the output opening 1 b . The output delivery unit 50 includes a rack transport member 51 , motor 52 , drive belt 53 , pulleys 54 a and 54 b , and direct-acting guide 55 .
[0102] The rack transport member 51 of the output delivery unit 50 is provided to transport a rack 5 , which has been moved to the output starting position P 6 , in the X 1 direction (output opening 1 b side). The motor 52 is linked to the pulley 54 a , and the drive belt 53 is installed on the pulleys 54 a and 54 b . Thus, the drive belt 53 is driven by the actuation of the motor 52 through the pulley 54 a . The direct-acting guide 55 is arranged so as to extend in the X 1 direction (X 2 direction). The rack transport member 51 is linked to the drive belt 53 , and mounted on the direct-acting guide 55 . Thus, the rack transport member 51 is moved in the direction of extension of the direct-acting guide 55 (X 1 direction and X 2 direction) by the actuation of the drive belt 53 .
[0103] The transport operation of the transporting apparatus 1 of the first embodiment is described below with reference to FIGS. 1, 5 , 9 , and 20 through 39 .
[0104] First, a first rack 5 is introduced through the entrance opening la to the input delivery unit 10 of the transporting apparatus 1 , as shown in FIG. 20 . At this time in the input delivery unit 10 , the conveyor belt 111 of the rack transport mechanism 11 is actuated. Thus, rack 5 is moved from the entrance opening la to the take-out position P 1 (refer to FIG. 5 ) by the conveyor belt 111 . Then, the arrival of the first rack 5 at the take-out position P 1 is detected by the detection unit 114 . The presence of the first rack 5 at the take-out position P 1 is detected by the transmission-type sensor 115 .
[0105] As shown in FIG. 21 , in the input delivery unit 10 , the take-out member 121 of the rack take-out mechanism 12 is moved in the Y 1 direction after the first rack 5 has arrived at the take-out position P 1 . Thus, the first rack 5 is moved from the takeout position P 1 to the rack receiving position P 2 (refer to FIG. 5 ). Then, the move of the first rack 5 from the take-out position P 1 to the rack receiving position P 2 is detected by the transmission-type sensor 115 . Furthermore, the presence of the first rack 5 at the rack receiving position P 2 (retention region outside the horizontal feed starting position P 3 of the retention unit 20 ) is detected by the transmission-type sensor 23 of the retention unit 20 .
[0106] Thereafter, in the retention unit 20 , the first rack 5 , which has arrived at the rack receiving position P 2 , is moved in the Y 1 direction by the connector 237 a (refer to FIG. 5 ) of the first rack transport mechanism 22 , as shown in FIG. 22 . Then, the retention regulating member 261 of the retention regulating mechanism 26 is housed below the installation surface 21 f of the retention plate 21 .
[0107] Thus, the first rack 5 , which has been moved in the Y 1 direction by the connector 237 a (refer to FIG. 5 ) of the first rack transport mechanism 22 , is not prevented from moving in the Y 1 direction by the retention regulating member 261 , and is transported to the horizontal feed starting position P 3 (refer to FIG. 5 ), as shown in FIG. 23 . Then, the arrival of the first rack 5 at the horizontal feed starting position P 3 is detected by the transmission-type sensor 24 .
[0108] In the retention unit 20 , when the first rack 5 arrives at the horizontal feed starting position P 3 (refer to FIG. 5 ), the movement of the first rack 5 in the Y 1 direction is stopped when the first rack 5 abuts the rack contact part 21 a of the retention plate 21 . The operation of the rack transport unit 22 b of the first rack transport mechanism 22 at this time is described below, as shown in FIG. 9 . The drive belt 225 , which is driven by the actuation of the motor 221 , is linked to the first moving member 229 of the rack transport unit 22 , and since the connector 237 a for engaging the first rack 5 is not mounted, the movement of the first moving member 229 in the Y 1 direction continues while the motor 221 is actuated. Since the drive belt 225 is not linked to the second moving member 230 of the rack transport unit 22 b , and the connector 237 a for engaging the first rack 5 is mounted through various parts, the movement of the second moving member 230 in the Y 1 direction is stopped. Thus, since only the first moving member 229 moves in the Y 1 direction against the force exerted by the compression spring 232 , the transmission-type sensor 240 mounted on the second moving member 230 is blocked by the detection piece mounted on the first moving member 229 . As a result, the movement of the first rack 5 to the horizontal feed starting position P 3 by the first rack transport mechanism 22 is stopped.
[0109] Thereafter, as shown in FIG. 24 , the specimen containers 4 accommodated in the first rack 5 are sequentially moved to the specimen supplying position 2 a ( 3 a ) when the horizontal feeding unit 30 moves the first rack 5 at the horizontal feed starting position P 3 a pitch of approximately 20 mm in the X 1 direction. The second through fourth racks 5 are transported to the retention region of the retention unit 20 in the same manner as the first rack 5 . Then, in the retention unit 20 , the retention regulating member 261 of the retention regulating mechanism 26 is projected from the installation surface 21 f of the retention plate 21 . Thus, the transport of the second and subsequent racks 5 to the retention regulating position P 4 is controlled by the retention regulating member 261 .
[0110] Then, when the first rack 5 has been completely moved from the horizontal fed starting position P 3 in the retention unit 20 , the retention regulating member 261 (refer to FIG. 5 ) of the retention regulating mechanism 26 is housed below the installation surface 21 f of the retention plate 21 , as shown in FIG. 25 . Then, with the retention regulating member 261 housed below the installation surface 21 f of the retention plate 21 , the second through fourth racks 5 are moved in the Y 1 direction by the connector 237 a (refer to FIG. 5 ) of the first rack transport mechanism 22 . Then, the second through fourth racks 5 are moved in the Y 1 direction until the second rack 5 is moved to the horizontal feed starting position P 3 (refer to FIG. 5 ).
[0111] Thereafter, in the retention unit 20 , the third and fourth racks 5 are moved in the Y 2 direction, that is, the direction opposite the transport direction, by the connector 237 b (refer to FIG. 5 ) of the first rack transport mechanism 22 , as shown in FIG. 26 . Then, the third and fourth racks 5 are moved in the Y 2 direction until the third rack 3 is moved to the retention region adjacent to the retention regulating position P 4 . Thereafter, the retention regulating member 261 of the retention regulating mechanism 26 projects from the installation surface 21 f of the retention plate 21 .
[0112] The operation when it is determined that repeat analysis is required for a specimen sample in a specimen container 4 accommodated in the first rack 5 in the state shown in FIG. 26 is described below.
[0113] When it is determined that repeat analysis is required for a specimen sample in a specimen container 4 accommodated in the first rack 5 , first, in the retention unit 20 , the retention regulating member 261 (refer to FIG. 5 ) of the retention regulating mechanism 26 is housed below the installation surface 21 f of the retention plate 21 . Thereafter, with the retention regulating member 261 housed below the installation surface 21 f of the retention plate 21 , the second rack 5 is moved to the retention regulating position P 4 (refer to FIG. 5 ) by the connector 237 b (refer to FIG. 5 ) of the first rack transport mechanism 22 .
[0114] Then, as shown in FIG. 28 , the first rack 5 is moved to the horizontal feed starting position P 3 (refer to FIG. 5 ) when the first rack 5 is transported in the X 2 direction (direction opposite the transport direction) by the horizontal feeding unit 30 . Thereafter, as shown in FIG. 29 , the first rack 5 is again moved to the specimen supplying position 2 a ( 3 a ) when the horizontal feeding unit 30 again moves the first rack 5 at the horizontal feed starting position P 3 a pitch of approximately 20 mm in the X 1 direction.
[0115] After the first rack 5 has been completely moved to the horizontal feed starting position, the second rack 5 is transported to the horizontal feed starting position P 3 by the connector 237 a (refer to FIG. 5 ) of the first rack transport mechanism 22 , so as to be returned to the condition prior to the repeat analysis condition (refer to FIG. 26 ).
[0116] The transport operation performed by the horizontal feeding unit 30 is described in detail below.
[0117] First, in the initial state shown in FIG. 30 , the rack transport unit 33 of the horizontal feeding unit 30 is moved to the initial position 30 a . When the rack transport unit 33 has been moved a pitch of approximately 20 mm in the X 1 direction, the transmission-type sensors 342 a and 342 b of the rack transport unit 33 operate as described below.
[0118] As shown in FIG. 30 , when the rack transport unit 33 is moved to the initial position 30 a , the transmission-type sensor 342 a is set to the transmission (ON) state, and the transmission-type sensor 342 b is set to the blocked (OFF) state. As shown in FIG. 31 , when the rack transport unit 33 is moved only approximately 20 mm (one pitch) from the initial position 30 a , the rack transport unit 33 is transported to the first transport position 30 c at which the transmission-type sensor 342 a is set to the OFF state, and the transmission-type sensor 342 b is set to the ON state. As shown in FIG. 32 , when the rack transport unit 33 is moved only approximately 40 mm (two pitches) from the initial position 30 a , the rack transport unit 33 is transported to the second transport position 30 d at which the transmission-type sensor 342 a is set to the ON state, and the transmission-type sensor 342 b is set to the OFF state. As shown in FIG. 33 , when the rack transport unit 33 is moved only approximately 60 mm (three pitches) from the initial position 30 a , the rack transport unit 33 is transported to the third transport position 30 e at which the transmission-type sensor 342 a and the transmission-type sensor 342 b are both set to the ON state. In the first embodiment, the rack 5 is transported by the horizontal feeding unit 30 to any among the first transport position 30 c at which the transmission-type sensor 342 a is set to the blocked (OFF) state and the transmission-type sensor 342 b is set to the transmission (ON) state; second transport position 30 d at which the transmission-type sensor 342 a is set to the transmission (ON) state and the transmission-type sensor 342 b is set to the blocked (OFF) state; and third transport position 30 e at which the transmission-type sensor 342 a and the transmission-type sensor 342 b are both set to the transmission (ON) state. The first transport position 30 c , second transport position 30 d , and third transport position 30 e are provided so as to be sequentially adjacent in the stated order in the transport direction (X 1 direction).
[0119] Thus, each time the rack transport unit 33 is moved one pitch in the X 1 direction, the rack 5 is transported to either he first transport position 30 c , second transport position 30 d , or third transport position 30 e , that is, the rack 5 is transported to a different transport position with each one pitch of movement. In this way the shift can be readily detected when the position of the rack 5 is shifted one pitch. Furthermore, since the movement of the rack 5 can be reliably detected, it is possible to specify the specimen container 4 in the rack 5 moved to the specimen supplying position.
[0120] In the horizontal feeding unit 30 , the barcode adhered on the first specimen container 4 of the first rack 5 is read when the first rack 5 is moved approximately 40 mm from the initial position 30 a by the rack transport unit 33 (refer to FIG. 32 ). As shown in FIG. 34 , when the first rack 5 is moved approximately 80 mm (four pitches) from initial position 30 a by the rack transport unit 33 , the specimen in the first specimen container 4 of the first rack 5 is agitated by the hand member 2 b (refer to FIG. 1 ) of the first blood analyzer 2 . As shown in FIG. 35 , when the first rack 5 is moved approximately 100 mm (five pitches) from initial position 30 a by the rack transport unit 33 , the specimen in the first specimen container 4 of the first rack 5 is supplied to the first blood analyzer 2 by the hand member 2 b ( 3 b ).
[0121] When it is determined that repeat analysis is required for a specimen sample in a specimen container 4 accommodated in the first rack 5 , the rack transport unit 33 is moved in the X 2 direction, as shown in FIG. 36 . Then, the rack transport unit 33 is moved in the X 2 direction until the transmission-type sensor 342 a of the rack transport unit 33 arrives at the region corresponding to the detection hole 343 h . At this time the transmission-type sensors 342 a and 342 b are set to the ON state and OFF state, respectively.
[0122] As shown in FIG. 37 , the first rack 5 is transported to the discharge starting position P 5 (refer to FIG. 5 ) when the first rack 5 is moved approximately 20 mm (one pitch) in the X 1 direction by the horizontal feeding unit 30 . Then, the arrival of the first rack 5 at the discharge starting position P 5 is detected by the transmission-type sensor 43 of the discharge unit 40 .
[0123] Then, in the discharge unit 40 , the first rack 5 , which has arrived at the discharge starting position P 5 (refer to FIG. 5 ) is moved in the Y 2 direction by the connector 421 (refer to FIG. 5 ) of the second rack transport mechanism 42 and arrives at the take-out starting position P 6 , as shown in FIG. 38 . Then, the arrival of the first rack 5 at the take-out starting position P 6 is detected by the transmission-type sensor 44 of the discharge unit 40 .
[0124] Finally, in the output delivery unit 50 , after the first rack 5 is moved to the takeout starting position P 6 , the rack transport member 51 is move din the X 1 direction, as shown in FIG. 39 . Thus, the first rack 5 is moved from the output opening 1 b since the first rack 5 at the take-out starting position P 6 is moved in the X 1 direction.
[0125] In the first embodiment described above, when the rack 5 is transported by the horizontal feeding unit 30 to either the first transport position 30 c , second transport position 30 d , or third transport position 30 e , whether or not the rack 5 has arrived at the transport position (first transport position 30 c , second transport position 30 d , or third transport position 30 e ) can be confirmed when the transmission-type sensors 342 a and 342 b detect the detection holes 343 a through 343 g by providing a horizontal feeding unit 30 for transporting a rack 5 to the specimen supplying position 2 a and 3 a of a first blood analyzer 2 or second blood analyzer 3 , transmission-type sensors 342 a and 342 b for detecting the transport position of the rack 5 , and detection holes 343 a through 343 g for indicating the transport positions (first transport position 30 c , second transport position 30 d , or third transport position 30 e ) detectable by the transmission-type sensors 342 a and 342 b . Therefore, the movement of the rack 5 can be reliably detected by the change in the detection status of the transmission-type sensors 342 a and 342 b even when the rack 5 is moved one pitch in either the X 1 direction or X 2 direction from the transport position (first transport position 30 c , second transport position 30 d , or third transport position 30 e ). Since the movement of the rack 5 can be detected in this way, it is possible to prevent supplying a specimen container 4 that is different from the specimen container 4 intended for current analysis to the first blood analyzer 2 or second blood analyzer 3 .
[0126] In the first embodiment, when the rack 5 is moved one pitch (20 mm) at a time in the X 1 or X 2 directions between two transport positions (first transport position 30 c , second transport position 30 d , or third transport position 30 e ), the movement of the rack 5 can be readily detected by providing sequentially adjacent first transport position 30 c , second transport position 30 d , and third transport position 30 e , and sequentially changing the detection status of the transmission-type sensor 342 a and transmission-type sensor 342 b among three different detection states.
[0127] In the first embodiment, in the retention unit 20 , the first transport mechanism for transporting a rack 5 at the rack receiving position P 2 to the horizontal feed starting position P 3 is configured so as to be capable of moving the rack 5 in a direction opposite the transport direction from the horizontal feed starting position P 3 toward the rack receiving position P 2 side, such that a rack 5 can be moved in a direction (Y 2 direction) opposite the transport direction from the horizontal feed starting position P 3 toward the rack receiving position P 2 side by the first rack transport mechanism 22 without intervention by an operator. Thus, when a specimen in a specimen container 4 accommodated in the first rack 5 is to be reanalyzed by the same analyzer (first blood analyzer 2 or second blood analyzer 3 ), the first rack 5 , which has been moved from the horizontal feed starting position P 3 to the specimen supplying position 2 a ( 3 a ), is transported again to the horizontal feed starting position P 3 and again retained in the retention unit 20 ; then, since the second rack 5 , which was previously moved to the horizontal feed starting position by the first rack transport mechanism 22 , can be moved to a region outside the horizontal feed starting position P 3 of the retention unit 20 when the retained first rack 5 is again moved from the horizontal feed starting position P 3 to the specimen supplying position 2 a ( 3 a ), the first rack 5 is ensured of the retention region (horizontal feed starting position P 3 ) in the retention unit 20 without the intervention of an operator. As a result, when a specimen is to be reanalyzed by the same analyzer (first blood analyzer 2 or second blood analyzer 3 ), the rack 5 (specimen sample) can be again transported to either the first blood analyzer 2 or the second blood analyzer 3 .
[0128] In the first embodiment, the racks 5 are moved one at a time by the connectors 237 a and 237 b of the first rack transport mechanism 22 by configuring the first rack transport mechanism 22 so as to include the connectors 237 a and 237 b for engaging the rack 5 . In this case, when a specimen in a specimen container 4 accommodated in the first rack 5 is to be reanalyzed by the same analyzer (first blood analyzer 2 or second blood analyzer 3 ), the first rack 5 can be assured of regaining the retention region (horizontal feed starting position P 3 ) in the retention unit 20 by setting a region the size of one rack 5 adjacent to the horizontal feed starting position P 3 on the rack receiving position P 2 side as a region for regulating the retention of a rack 5 , and moving only the second rack 5 , which has already been moved to the horizontal feed starting position P 3 , to the region (retention regulating position P 4 ) adjacent to the horizontal feed starting position P 3 on the rack receiving position P 2 side.
Second Embodiment
[0129] FIG. 40 is a plan view showing the structure of the transporting apparatus of a second embodiment of the present invention. FIGS. 41 and 42 show details of the structure of the transporting apparatus of the second embodiment of FIG. 40 . The aspects of the second embodiment which differ from those of the first embodiment are described below in the case of the transport of a rack 5 by a conveyor belt 825 in a retention unit 80 with reference to FIGS. 3 , and 40 through 42 . The rack 5 , which is moved by the transporting apparatus 100 of the second embodiment, is identical to the rack 5 shown in FIGS. 2 and 3 .
[0130] The transporting apparatus 100 of the second embodiment is provided with an input delivery unit 70 , retention unit 80 , horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 , as shown in FIG. 40 . The structures of the horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 of the transporting apparatus 100 of the second embodiment are identical to the structures of the horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 of the transporting apparatus 1 of the first embodiment.
[0131] The input delivery unit 90 of the transporting apparatus 100 is provided to transport a rack 5 , which has been introduced from the entrance opening 100 a of the transporting apparatus 100 , in the X 1 direction to the retention unit 80 side. The input delivery unit 70 includes a drive unit 71 , a rack transport unit 72 , and transmission-type sensors 73 a and 73 b.
[0132] The drive unit 71 of the input delivery unit 70 is provided to move the rack transport unit 72 in the X 1 direction and X 2 direction. The drive unit 71 is configured by a motor 711 , drive belt 712 , pulleys 713 a and 713 b , and a direct-acting guide 714 . The motor 711 is linked to the pulley 713 a , and the drive belt 712 is installed on the pulleys 713 a and 713 b . Thus, the drive belt 712 is driven by the actuation of the motor 711 through the pulley 713 a . The direct-acting guide 714 is arranged so as to extend in the X 1 direction (X 2 direction).
[0133] The rack transport unit 72 of the input delivery unit 70 is provided to move a rack 5 introduced from the entrance opening 100 a in the X 1 direction, and functions as a retention regulating member. The input starting position 70 a in FIG. 40 is the position where the rack 5 begins to be taken in by the rack transport unit 72 , and the input ending position 70 b in FIG. 40 is the position where the rack 5 input by the rack transport unit 72 ends. The rack transport unit 72 has a moving member 721 , solenoid 722 , and microswitch 723 . The moving member 721 is linked to the drive belt 712 , and mounted on the direct-acting guide 714 . Thus, the moving member 721 is moved in the X 1 direction along the direct-acting guide 714 when the drive belt 712 is driven in the X 1 direction. The moving member 721 has a contact part 721 a that comes into contact with a rack 5 introduced from the entrance opening 100 a . The rack 5 abuts the contact part 721 a of the moving member 721 and in this condition is moved in the X 1 direction by the rack transport unit 72 .
[0134] The microswitch 723 of the rack transport unit 72 is mounted on the contact part 721 a of the moving member 721 . The microswitch 723 is arranged such that the switch part of the microswitch 723 is pressed by the rack 5 when the rack 5 abuts the contact part 721 a of the moving member 721 . Thus, when a rack 5 abuts the contact part 721 a of the moving member 721 , the contact of the rack 5 with the contact part 721 a is detected since the microswitch 723 is switched from the ON (OFF) state to the OFF (ON) state.
[0135] The solenoid 722 of the rack transport unit 72 is mounted on the moving member 721 . The solenoid 722 is arranged such that the rod 722 a of the solenoid 722 extends in the Y 1 direction, and the rod 722 a is inserted into a channel 5 c (refer to FIG. 3 ) of a rack 5 abutting the contact part 721 a of the moving member 721 . Thus, when the rod 722 a of the solenoid 722 is inserted into the channel 5 c of the rack 5 and the rack transport unit 72 is moved in the X 1 direction, the rack 5 is moved in the X 1 direction by the engagement of the rod 722 a of the solenoid 722 with the channel 5 c of the rack 5 .
[0136] The transmission-type sensors 73 a and 73 b of the input delivery unit 70 are provided to detect the position of the rack transport unit 72 moving the X 1 direction and X 2 direction. That is, the transmission-type sensor 73 a is provided to detect the movement of the rack transport unit 72 to the input starting position. The transmission-type sensor 73 a is disposed such that the light is blocked by a detection piece (not shown in the drawing) of the moving member 721 of the track transport unit 72 when the rack transport unit 72 has been moved to the input starting position 70 a . The transmission-type sensor 73 b is provided to detect the movement of the rack transporting unit 72 to the input ending position 70 b . The transmission-type sensor 73 b is disposed such that the light is blocked by a detection piece (not shown in the drawing) of the moving member 721 of the track transport unit 72 when the rack transport unit 72 has been moved to the input ending position 70 b . When the rack transport unit 72 has been moved to the input starting position 70 a , the moving member 721 of the rack transport unit 72 is positioned in a predetermined region above a retention plate 81 described later. When the rack transport unit 72 has been moved to the input ending position 70 b , the moving member 721 of the rack transport unit 72 is position in a region separated from the retention plate 81 described later.
[0137] The retention unit 80 of the transporting apparatus 100 is provided to retain a rack 5 that has been moved from the entrance opening 100 a to the specimen supplying position 2 a ( 3 a ). In the second embodiment, when a repeat analysis is to be performed, the retention unit 80 has the function of retaining a rack 5 that has been moved from the specimen supplying position 2 a ( 3 a ) in a direction opposite the transport direction. The retention unit 80 includes a retention plate 81 , first rack transport mechanism 82 , and barcode reader 83 .
[0138] The retention plate 81 of the retention unit 80 has three divisions, and the three divisions of the retention plate 81 are arranged at mutually predetermined spacing. The retention plate 81 is arranged so as to have a region through which the rack transport unit 72 (contact part 721 a of the moving member 721 ) of the rack transport unit 72 passes as it moves in the X 1 direction (X 2 direction). The retention plate has a rack contact part 81 a . The rack contact part 81 a is provided on the retention plate 81 on the opposite side from the input delivery unit 70 . The rack contact part 81 a is formed by bending the retention plate 81 in a direction perpendicular to the installation surface 81 b. The region between the rack contact part 81 a and the end of the retention plate 81 on the input delivery unit 70 side is a retention region capable of retaining a rack 5 . In the retention rack 81 , the region through which the rack transport unit 72 of the input delivery unit 70 passes is the rack receiving position for receiving a rack 5 transported by the input delivery unit 70 . A region of the size of a single rack 5 on the rack contact part 81 a side of the retention plate 81 is the horizontal feed starting position for starting the transport of a rack 5 by the horizontal feeding unit 30 .
[0139] In the second embodiment, the retention of a rack 5 to the rack receiving position P 22 is regulated by the moving member 721 when the rack transport unit 72 (moving member 721 ) of the input delivery unit 70 is moved to the input starting position 70 a . That is, when the rack transport unit 72 (moving member 721 ) of the input delivery unit 70 is moved to the input starting position 70 a , the rack transport unit 72 (moving member 721 ) functions as a retention regulating member to regulate the retention of the rack 5 toward the rack receiving position P 22 . When the rack transport unit 72 is moved to the input ending position 70 b , the rack transport unit 72 (moving member 721 ) does not function as a retention regulating member since the rack transport unit 72 (moving member 721 ) is positioned in a region separated from the retention plate 81 . Moreover, the transport of the rack 5 toward the rack receiving position P 22 starts when the rack transport unit 72 is present in a region capable of retaining at least one rack 5 in a region outside the rack receiving position P 22 of the retention unit 80 .
[0140] The first rack transport mechanism 82 of the retention unit 80 has the function of moving a rack 5 in a direction (Y 2 direction) opposite the transport direction from the horizontal feed starting position P 23 side to the rack receiving position P 22 side in addition to the function of moving a rack 5 retained on the retention plate 81 from the rack receiving position P 22 side to the horizontal feed starting position P 23 side (Y 1 direction). The first rack transport mechanism 82 is disposed below the installation surface 81 b of the retention plate 81 . The first rack transport mechanism 82 is configured by a cylinder 82 , direct-acting guide 822 , holder 823 , motor 824 , two drive belts 825 , a pair of pulleys 826 a and a pair of pulleys 826 b , a plurality of tension pulleys 827 , pulley shaft 828 , drive belt 829 , and transmission-type sensor 830 . The cylinder 821 is disposed so as to extend in a direction (Z direction) perpendicular to the installation surface 81 b of the retention plate 81 , and the direct-acting guide 822 is arranged so as to extend in the Z direction. The holder 823 is mounted on a cylinder rod 821 a and the direct-acting guide 822 . Thus, the holder 823 is moved in the direction of extension of the direct-acting guide 823 by the cylinder rod 821 a extending in the Z direction.
[0141] In the first rack transport mechanism 82 , the motor 824 , pulley pair 826 a and pulley pair 826 b , and the plurality of tension springs 827 are mounted on the holder 823 . The pulley pair 826 a are arranged so as to mutually confront one another separated by a predetermined distance, and the pulley pair 826 b are arranged so as to confront one another separated by the same distance as that separating the pulley pair 826 a . The two transport belts 825 are respectively installed on the pulleys 826 a and 826 b on one side, and pulleys 826 a and 826 b on the other side. The transport belts 825 on one side and the other side are arranged so as to project from the installation surface 81 b through the regions corresponding the medial areas between the three divisions of the retention plate 81 when the holder 823 is moved in the Z direction. A tension is applied by the plurality of tension springs 827 to the transport belts 825 installed on the pulleys 826 a and 826 b.
[0142] In the first rack transport mechanism 82 , the pulley shaft 828 is linked to the pair of pulleys 826 a , and the drive belt 829 is installed on the pulley shaft 828 and the rotating shaft of the motor 824 . Thus, the transport belt 825 is driven by the actuation of the motor 824 through the drive belt 829 , pulley shaft 828 , and pulley 826 a . When the transport belt 825 is driven in the Y 1 direction (Y 2 direction) while protruding from the installation surface 81 b , the rack 5 is move din the Y 1 direction (Y 2 direction) by means of the contact of the rack 5 with the driven transport belt 825 .
[0143] The transmission-type sensor 830 of the first rack transport mechanism 82 is provided to detect the transport belt 825 projecting from the installation surface 81 b of the retention plate 81 . The transmission-type sensor 830 is disposed such that the light is blocked by a detection piece 823 a mounted on the holder 823 when the transport belt 825 projects from the installation surface 81 b of the retention plate 81 .
[0144] FIGS. 43 through 47 are schematic views illustrating the transport operation of the transporting apparatus of the second embodiment of the present invention. The rack transport operation of the transporting apparatus 100 of the second embodiment is described below with reference to FIGS. 40 , and 43 through 47 .
[0145] In the retention unit 80 , the first through sixth racks 5 sequentially transported from the input delivery unit 70 are moved in the Y 1 direction by the transport belt 825 of the first rack transport mechanism 82 , as shown in FIG. 43 . Then, the first rack 5 is moved to the specimen supplying position 2 a ( 3 a ) by moving the first rack 5 at the horizontal feed starting position P 23 (refer to FIG. 40 ) approximately 20 mm (one pitch) in the X 1 direction (transport direction). When the first rack 5 is moved completely from the horizontal feed starting position P 23 , the second through sixth racks 5 are moved in the Y 1 direction by the transport belt 825 of the first rack transport mechanism 82 . Then, the second through sixth racks 5 are moved in the Y 1 direction until the second rack 5 reaches the horizontal feed starting position P 23 . Thereafter, the rack transport unit 72 of the input delivery unit 70 is moved to the input starting position 70 a (X 2 direction).
[0146] The operation when it is determined that repeat analysis is required for a specimen sample in a specimen container 4 accommodated in the first rack 5 in the state shown in FIG. 43 is described below.
[0147] When it is determined that repeat analysis is required for a specimen sample in a specimen container 4 accommodated in the first rack 5 , first, in the input delivery unit 70 , the rack transport unit 72 is moved to the input ending position 70 b (X 1 direction), as shown in FIG. 44 . As shown in FIG. 45 , the second through sixth racks 5 are
[0148] moved in the Y 2 direction, that is, a direction opposite the transport direction, by the transport belt 825 of the first rack transport mechanism 82 . Then, the second through sixth racks 5 are moved in the Y 2 direction until the sixth rack 5 reaches the rack receiving position P 22 (refer to FIG. 40 ).
[0149] As shown in FIG. 46 , the first rack 5 is moved to the horizontal feed starting position P 23 by moving the first rack 5 in the X 2 direction, that is, a direction opposite the transport direction by the horizontal feeding unit 30 .
[0150] Thereafter, as shown in FIG. 47 , the first rack 5 is again moved to the specimen supplying position 2 a ( 3 a ) by again moving the first rack 5 at the horizontal feed starting position P 23 approximately 20 mm (one pitch) in the X 1 direction. After the first rack 5 has been completely moved from the horizontal feed starting position P 23 , the second rack 5 is transported to the horizontal feed starting position P 23 by the transport belt 825 of the first rack transport mechanism 82 , so as to be returned to the condition prior to the repeat analysis condition (refer to FIG. 43 ).
[0151] The transport operations in the horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 of the second embodiment are respectively identical to the transport operations of the horizontal feeding unit 30 , discharge unit 40 , and output delivery unit 50 of the first embodiment.
[0152] In the second embodiment, the first rack transport mechanism 82 is configured to include the transport belt 825 to move the rack 5 , and all racks 5 retained in the region outside the rack receiving position P 22 of the retention unit 80 can be moved simultaneously in a direction opposite the transport direction from the horizontal feed starting position P 23 side to the rack receiving position P 22 side by the transport belt 825 of the first rack transport mechanism 82 . In this case, when a specimen in a specimen container 4 accommodated in the first rack 5 is to be reanalyzed by the same analyzer, the second rack 5 , which was previously moved to the horizontal feed starting position P 23 , can be moved together with the third and subsequent racks 5 to a region outside the horizontal feed starting position P 23 of the retention unit 80 by setting the rack receiving position P 22 as a region for regulating the retention of racks 5 , such that a region (horizontal feed starting position P 23 ) for again retaining the first rack 5 in the retention unit 80 can be readily ensured.
[0153] The above disclosed embodiments are to be considered examples in all respects and in now manner limiting of the invention. The scope of the present invention is expressed in the scope of the claims and not in the description of the embodiments, and all modifications within the scope and meaning of equivalences are included within the scope of the claims.
[0154] For example, although the transporting apparatus of the present invention is connected to blood analyzers in the first and second embodiments, the present invention is not limited to this arrangement inasmuch as the transporting apparatus of the present invention may also be connected to specimen processing apparatuses other than blood analyzers.
[0155] Although the first embodiment has been described by way of example in which the transmission state and blocked state of transmission-type sensors 342 a and 342 b of the rack transport unit 33 are changed by providing detection holes (light transmission holes (light transmission part)) in a detection plate 343 , the present invention is not limited to this arrangement inasmuch as the transmission state and blocked state of transmission-type sensors 342 a and 342 b of the rack transport unit 33 may be changed by providing a light blocking part capable of being detected by the sensors 342 a and 342 b.
[0156] Although the example of the first embodiment uses two transmission-type sensors 342 a and 342 b , the present invention is not limited to this arrangement inasmuch as three or more transmission-type sensors may be used. For example, when three transmission-type sensors are used, eight different patterns can be provided, excluding the pattern when all transmission-type sensors are OFF.
[0157] Although rack transport is accomplished by a first moving mechanism having connectors or transport belts in a retention unit in the first and second embodiments, the present invention is not limited to this arrangement inasmuch as the racks may be transported by a first transport mechanism other than a first transport mechanism having connectors or transport belts.
[0158] Although the first embodiment is described by way of an example in which two transmission-type sensors 342 a and 342 b are mounted on a moving member 33 of a rack transport unit and move together with the moving rack while the detection plate 343 is stationary, it is to be noted that the detection plate 343 may be mounted on the moving member 331 of a rack transport unit so as to move together with the moving rack while the two transmission-type sensors 342 a and 342 b are stationary. | A transporting apparatus is described, a representative one of which includes a transporting apparatus which transports at least one specimen container accommodated in a rack to a specimen supplying position for supplying a specimen processing apparatus, comprising: a transport mechanism configured to transport the at least one specimen container to the specimen supplying position by transporting the rack; and a detection unit for obtaining information specifying the position of the rack being transported by the transport mechanism. | 6 |
[0001] This application is a continuation-in-part of U.S. Utility patent application Ser. No. 12/814,868 filed 14 Jun. 2010, which is a divisional of U.S. patent application Ser. No. 11/608,111 filed 7 Dec. 2006, now U.S. Pat. No. 7,758,782, which takes priority from German Patent Application DE 10 2005 059 375.5 filed 9 Dec. 2005, the specifications of which are all hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention relate to a powder mixture for manufacture of a battery electrode, a respective battery electrode, and a method of manufacturing of an active material powder mixture for the production of battery electrodes, particularly for lithium batteries. Embodiments of the invention further relate to the method for manufacturing of a respective battery electrode.
[0004] 2. Description of the Related Art
[0005] Batteries are sources for electrical energy which are commonly used. Important elements of a battery are the negative electrode, typically called the anode, and the positive electrode, typically called the cathode. Usually, the anode comprises active material that can be oxidized and the cathode comprises active material that can be reduced.
[0006] One well-known method for manufacturing of an electrode (anode or cathode) uses powder mixtures. For example, battery electrodes are produced by wet coating methods. In these methods, the powder is dispersed together with a binder in a solvent. The solvent is selected for this purpose so that it wets the components of the powder sufficiently and simultaneously it has a sufficiently high solubility for the binder. Aqueous dispersions or dispersions based on organic solvents (e.g., alcohols, ketones, amines, amides, ethers) are used for this purpose. These dispersions are applied to an electrically conductive carrier (e.g., metals, conductively coated polymers) and the solvent is removed by drying.
[0007] The disadvantages of this method are manifold. The production of the dispersions is time-consuming and costly and the useful lives of the dispersions are frequently limited by coagulation or sedimentation. Furthermore, secondary reactions occur due to the decomposition of the solvent(s), possibly also due to secondary reactions with the dispersed substances or with the dissolved binders. These lower the useful lives of the coating solutions. Disadvantages arise both with aqueous coating solutions and also with organic solvents. Aqueous coating solutions are nontoxic, but may only be dried with difficulty. Long drying times or high drying temperatures are necessary. Moisture-sensitive materials may not be coated by aqueous solvents. Organic solvents typically require a high technical outlay (explosion protection, fire protection, solvent reclamation/solvent combustion). The requirements for labor protection (toxicity, annoyance due to bad smells) are typically high. Quantitative reclamation is typically not possible. The production of homogeneous coatings is technically demanding and costly because of the rheological properties of the dispersions and the drying of such coatings produces high energy costs and is time-consuming.
[0008] Above all in lithium batteries, the selection of the binders stable under the operating conditions of the battery is limited. Often, only fluorinated polymers are usable. These are frequently only soluble in special, expensive organic solvents having high boiling points. The solvents increase the porosity of the coating during the drying process. To increase the energy density of the coating, additional work steps are therefore necessary after the drying to compact the electrodes (pressing, calendering).
[0009] Further methods known from the prior art are pressing methods. In these methods, powder mixtures are compressed to form tablets, rings, or cups (pressed parts). The powder mixtures may also be processed to form strands or films by extrusion. The electrical discharge of the current occurs in this case by laminating on a metallic current collector, possibly with the aid of an electrically conductive adhesive. The contact may also be produced by a simple press contact. The discharge is frequently ensured by a press contact with the housing of the battery or by a nail which is driven into the pressed part.
[0010] These methods also have disadvantages. The contact areas of the pressed parts for the press contacting are typically small, the carrying capacity of the batteries is limited. Furthermore, disadvantages have been established if a homogeneous material bond is not produced between the current collector and the housing (e.g., by welding). The transition resistance of the press contact may then rise in the course of the battery life due to the formation of cover layers, due to gas development, or due to corrosion. A rise of the transition resistance of press contact has also been established when the pressure which acts on the press contact is reduced in the course of the battery life. The causes of this could, for example, be an expansion of the housing due to swelling of the battery materials or due to gas development.
[0011] In hermetically sealed batteries, in which no polymer seals could be used for sealing and insulating housing parts, only one electrode could be electrically connected by a press contact. The other electrode must be electrically connected to the battery housing using a bushing insulated from the battery housing (e.g., a glass-metal bushing). A connection of the electrode to a current collector is required for this purpose.
[0012] A further grave disadvantage is the low mechanical stability of the pressed parts. Because of this disadvantage, there must be a sufficiently high wall thickness according to the prior art. This results in a low electrical carrying capacity of the battery. For mechanical stabilization, the pressing method may be performed directly in the battery housing (e.g., with alkali manganese batteries). This requires sufficient material thicknesses of the housing and is bound to suitable housing geometries (cylindrical housing). It has also been shown that laminating on a current collector represents an additional time-consuming and costly work step.
[0013] In many cases powdered materials and/or mixtures of powdered materials are used to produce battery electrodes. These are coated on an electrically conductive material, which is used as the current collector. The powdered materials are therefore preferred because they form porous structures having a large surface in relation to the ion-conducting electrolytes. A high carrying capacity of the battery electrode per unit area is thus achieved.
[0014] In particular for thin electrodes e.g. for high-power applications in implantable Cardioverter Defibrillators with typically electrode thicknesses below 0.8 mm fine powders of an active material, binder or, if applicable, additive have to be used. Additionally, the powders of the components of the electrode must be dosed exactly, in order to reach an exact composition of the electrode material.
[0015] Fine powders or mixtures of fine powders show a limited flowability, in particular if materials with low density are used (for example carbon black or graphite, which are often used as additives). This limited flowability leads to difficulties in powder dosing, in particular in an automated production process. This property is particularly a disadvantage if the powders or powder mixtures are used to produce low bulk heights with uniform layer thickness.
[0016] Powder is a disperse system which consists of a plurality of single particles. A bulk powder mixture is a homogeneous mixture of powders (primary particle system) without stable interparticular connection.
[0017] Different methods for manufacturing of electrode powder mixture are known. Document DE 10 2007 034 178 A discloses a method for manufacturing of electrodes using suspensions comprising active nano material. The documents U.S. Pat. No. 7,527,895 B2 and U.S. Pat. No. 6,946,220 describe the production of high power electrodes for lithium batteries by wet coating.
[0018] Therein, the additives (for example black carbon or graphite) are pre-mixed with the active material (for example LiNiCoAlO 2 , MnO 2 , FeS 2 , Ag x V 2 O y ) and are then suspended in a binder solution. Within the binder solution a polymer solvent (for example PvdF, PTFE) adsorbs to the surface of the active material particle forming a binder coating. The coating promotes the adhesion of the additive particles.
[0019] Such suspensions are then applied onto current collectors (for example a grid or a foil) using a wet coating apparatus. The coated current collectors are then dried to the necessary residual moisture for lithium batteries on a drying band-conveyer. The electrode packet (anode or cathode) is then produced using a winding or stacking technology.
[0020] From document U.S. Pat. No. 5,571,637 it is known that a wet active material (paste) is compressed in order to get electrode pellets. The pellets are subsequently dried. Additionally, dry-pressing of active material powder is described in order to produce electrodes.
[0021] During wet coating of solvent containing suspensions according to the state of the art methods a drip time of the coating solutions has to be considered. Another disadvantage of these state of the art methods is that solutions sediment or exhibit a limited handling duration. The handling duration is getting the shorter, the more reactive the used active material with the binder, the solvent or the additive is.
BRIEF SUMMARY OF THE INVENTION
[0022] A feature of one or more embodiments of the invention is, to specify a novel method for powder manufacturing and battery electrodes manufacturing from powder mixtures, which overcome the disadvantages known from the prior art. Further, a respective powder mixture and a respective electrode are developed.
[0023] This feature is obtained as claimed herein.
[0024] In particular, the feature is achieved by a powder mixture comprising predominantly agglomerates containing both, particles of an active material and particles of at least one binder. It is also possible to use mixtures of different active materials.
[0025] By agglomeration of powder particles, which are, in particular, spherical, the flowability of the powder is enhanced. The inventive granulate material allows the automatic production of homogeneous powder bulk material with low bulk height. This powder bulk can be compacted in an automatic pressure process in order to produce very thin, mechanically stable battery electrodes.
[0026] Within this invention a granulate material or agglomerate is a particle organization having mechanically stable agminated or linked fine disperse primary particles.
[0027] In a preferred embodiment, the agglomerates further comprise particles of at least one additive.
[0028] The additives improve the properties of the electrode.
[0029] It is further advantageous, if the particles of the at least one binder are fine dispersively distributed between the particles of the active material and, if applicable, the particles of the at least one additive within the agglomerates.
[0030] By granulation of active material particles with binder particles and, optional, with additive particles, the flowability of the powder mixture is substantially enhanced. This is in particular true, if carbon black or graphite is used as an additive for the improvement of the electrical conductivity of the battery electrode.
[0031] The above feature is further obtained by a method for manufacturing of the powder mixture comprising the following steps:
[0032] Suspending of particles of at least one binder within an inert solvent producing a first suspension;
[0033] Preferably slowly suspending of particles of an active material within said first suspension producing a second suspension;
[0034] Drying of said second suspension producing a granulate.
[0035] The inventive method can be used for the production of anodes and cathodes of batteries, in particular lithium batteries. In principle, all powder battery materials are suited for the inventive procedure.
[0036] In an embodiment of the invention, after drying of the second suspension the granulate material is sieved by a sieve with a predefined mesh width in order to get a granulate material with a predefined size of the granules.
[0037] In a preferred embodiment sieve cascades with meshes of 800 μm to 300 μm are used.
[0038] It is further preferred, if between the production of the first suspension and the production of the second suspension particles of at least one additive are suspended within the first suspension. This is the most cost-effective way to add the additives enhancing the properties of the electrode material.
[0039] For the manufacturing of cathodes active material can be used, such as:
[0040] Metal oxides, for example manganese dioxide, lithium cobalt oxide, lithium manganese spinel, lithium nickel cobalt oxide, silver vanadium oxide;
[0041] Metal phosphates, for example copper oxyphosphates, iron phosphates, vanadium oxyphosphates;
[0042] Metal vanadates, for example copper vanadate;
[0043] Metal chromates, for example lead chromate.
[0044] For the production of anodes, active material can be used, such as:
[0045] Carbons, for example graphite, meso-carbon compositions;
[0046] Metal-oxides, for example lithium-titanium-oxide;
[0047] As a binder the material can be used, such as:
[0048] Polyvinylidendifluorid, Polyethylene, Polypropylene.
[0049] As an additive the materials can be used, such as:
[0050] Carbon black, graphite, expanded graphite, carbon fibers, metals and porosity promoters, like ammonium-carbonate.
[0051] For the production of the granulate material a low boiling solvent (Ts<150° C.) is used. It is important that the solvent is chemically inert with regard to the active material, the binder or the additive. Additionally, the binder is not or only very weak soluble within the solvent. As a solvent, for example, alkanes or cycloalkanes can be used.
[0052] From the particulate at least one binder a first suspension is produced using the solvent. Then, a second suspension is produced from the first suspension and the particles of the active material. In particular, a high shear mixing aggregate, for example a toothed ring disperser, can be used. During the production of the first and the second suspensions, the binder is not solved but its particles are finely dispersed. The suspended binder particles are finely dispersive distributed between the components of the active material. The binder is not adsorbed at the whole surface of the active material because of the low solubility of the binder within the solvent. In particular, no coating is formed on the surface of the active material by the binder.
[0053] The solvent is removed after complete homogenization of the suspension by distillation. Then, a granulate material occurs as a result of the inventive procedure which is free flowing and can be used for the manufacturing of thin electrodes.
[0054] By using a chemically inert solvent, for example alkanes or cycloalkanes, no chemical reaction of the solvent with the binder or the active material is observed. Therefore, using the inventive method, very reactive metal oxides can be processed. They do not show undesirable secondary reactions with the solvent or the dissolved binder during the wet chemical coating procedure as in other state of the art techniques.
[0055] Another advantage of the inventive method is that no traces of solvent appear within the electrode. Such solvent traces would impair the properties of the battery, because the solvent of the granulation would react with the components of the battery material.
[0056] Additionally, there is no limit of the handling duration or storage time for suspensions of the granulate material and the granulate material. In contrast to that, the suspensions for wet coating method show very limited handling duration or storage time.
[0057] Often there is an increase in temperature observed during the production of the suspensions caused by shearing. Regarding the inventive method, this does not lead to the intensification of secondary reactions between the solvent and the binder or the active material or the additive because the solvent is inert. Additionally, by using a high shear disperser the chain length of the polymers used within the inventive method is not shortened. The polymers are not physically diluted within the solvent but fine dispersively distributed within the suspension.
[0058] Other granulating or wet drying methods for the production of electrodes require solvents which are able to dilute the binder in order to form a coating. In contrast to that, during the inventive procedure, the solvent is only a tool for processing which distributes the binder particles fine dispersively between the other particulate components of the electrode material. Therefore, it is possible to use a bigger variety of binder-solvent-combinations with the inventive method. For the described process olefines or cyclic olefines are preferably being used e.g. hexane, cyclohexane, heptane, octane. Other solvents without significant solubility for the used binder and—depending on the active materials—without reactivity with the active electrode material can alternatively be used, e.g. ethers, alcohols.
[0059] For example, fluoric polymers, (i.e. Polyvinylidendifluorid) can be solved only in a very small number of solvents. These solvents, for example N-Methylpyrrolidon, show many unwanted secondary reactions with the active material. This is not observed using the inventive method.
[0060] The adhesion of the binder particles to the active material is observed mainly during the application of pressure. Prior the compaction step during the manufacturing of the electrode (see below) the produced granulate material shows only a weak affinity to agglomeration, so that a very precise dosing of the powder is possible.
[0061] It is well-known that coating forming polymers may impair the electrical loading capacity of the electrode active material, because the particle surfaces are changed by the binder coating. By the polymer coating, the ion conductivity between electrolyte and particle surface and the wettability of the particle surfaces by the electrolyte can be impeded. Pore size of the active material may be diminished by the polymer film or the pores may be inaccessible for the electrolyte. As the inventive method does not produce a binder film at the surface of the active material no surface effects diminishing the battery power are observed.
[0062] The person skilled in the art further knows that by using solvents reacting with the binder in an oxidation or reduction secondary compounds may be formed which are soluble within the electrolyte of the battery. Additionally, reactions between the electrolyte and those secondary reaction products are possible. If from these reaction products metal ions dissolve within the electrolyte, these metal ions could be deposited at the anode of the battery. Therefore such battery coating at the electrodes leads to voltage-delay of the batteries. The deposited substances cause an increase of impedance and therefore a decrease of discharging capability of the battery. With regard to re-chargeable batteries, the number of charging and re-charging cycles of the battery may be diminished by this process. In contrast to that the solvent of the inventive procedure does not react with the active material. Therefore, such severe consequences of secondary reactions are obviated using the inventive method.
[0063] As explained above, the manufacturing of the battery electrodes is done without solvent. The solvent is used for granulation, is recovered and can be reduced within a circulate process.
[0064] Therefore, the production process of the electrodes can be done without difficulty. It is not necessary to dispose the solvent.
[0065] The above feature is further achieved by a battery electrode containing a compacted powder mixture and a current collector, wherein the powder mixture and its manufacturing are described above.
[0066] In an embodiment of the inventive electrode the electrically current collector is covered on both sides by said compacted powder mixture. This is a cost effective method for continuous production of electrodes (as well as handling and storage). Dry compaction of granulated materials is advantageous because of the outstanding mechanical stability and handling properties of the electrodes. Additional to that there is a high precision in thickness and weight with small standard deviations and there is no need to measure each electrode before battery mounting.
[0067] Further, it is preferred that the current collector is a metallic grid.
[0068] More specific the metallic grid is etched and/or embossed and/or stamped or a grid made of stretched metal. However, any other suitable shape and/or any other suitable material may also be provided for the current collector.
[0069] The above feature is further solved by a method for manufacturing of a battery electrode comprising the following steps:
[0070] Pouring a first quantity of a powder mixture into a cavity, wherein said powder mixture comprises at least two components;
[0071] Laying a current collector onto said powder mixture;
[0072] Pouring a second quantity of said powder mixture into said cavity;
[0073] Compressing said first powder mixture quantity and said second power mixture quantity onto said current collector to form said battery electrode.
[0074] Preferably, the powder mixture is a powder mixture of an agglomerate material according to the above explanations.
[0075] In a further method variation, a current collector in the form of a metallic grid is first positioned in a filling cavity, for example horizontally, and the powder mixture is then provided. The powder mixture then flows through the grid of the current collector and forms a predefined quantity of the powder mixture above and below the grid, for example substantially 50% above and 50% below the grid or any other ratio so long as each side of the grid may be coated. Finally, the compression under pressure is performed.
[0076] The advantages of this method are, inter alia, that no solvent is necessary in the production of the electrodes. The drying of the electrodes is thus dispensed with, since the powdered starting materials used already have the moisture required for the later application.
[0077] Furthermore, it is now possible to produce very thin electrodes with a low binder content.
[0078] One advantage of one or more embodiments of the invention is the connection of a current collector to the pressed part. A method is described for integrating a current collector directly into a powder mixture, without lamination.
[0079] A further advantage is that no additional work steps are required for compressing the electrode and the electrode is connected to the current collector in one work cycle. This method according to one or more embodiments of the invention also allows the stabilization of the geometry by the current collector.
[0080] Further a device is explained which allows parts of a current collector not to be coated during the compression procedure. The device comprises a filling cavity, into which the powder mixture is poured to produce a positive and/or negative battery electrode. The powder mixture is pressed together with a current collector and shaped into a battery electrode by compression means, which preferably comprise an upper plunger and especially preferably an upper plunger and a lower plunger.
[0081] The current collector comprises parts to be coated and parts not to be coated. The parts to be coated are to be coated by the powder pressing. In order to protect parts of a current collector not to be coated from coating and damage occurring due to the pressing, the current collector is positioned in a support and a counter support. The support and the counter support preferably comprise pins, the support being formed by a spring-mounted pin. The section of the current collector not to be coated is laid on the support and then covered by the further pin. The support is laid out so that it may change position with the height changes occurring during the pressing and the ratio of the heights of the partial quantities of the powder mixtures above and below the current collector thus remains essentially maintained during the compression procedure.
[0082] Further, the device may comprise a two-part filling cavity in the form of two matrices, between which the current collector is positioned. In this embodiment, a symmetrical pressing is performed by two compression means in the form of an upper plunger and a lower plunger. The current collector lying between the two matrices is pressed together from both sides with the powder mixture.
[0083] The advantage of the device is that no waste and no scrap are possible. The production allows complex geometries, outstanding shaping, and high mechanical stability of the battery electrodes. Furthermore, high working speeds are possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0084] In the following, one or more embodiments of the invention is explained in greater detail on the basis of exemplary embodiments and the associated drawings:
[0085] FIG. 1 shows an illustration of a compression press and the methods of asymmetrical and symmetrical pressing from the prior art.
[0086] FIG. 2 shows a schematic illustration of the powder pressing method using prepressed pressed parts and subsequent pressing together with a current collector.
[0087] FIG. 3 shows a preferred method according to an embodiment of the invention for pressing a battery electrode.
[0088] FIG. 4 shows a further preferred method according to an embodiment of the invention for pressing a battery electrode.
[0089] FIG. 5 shows a device for producing battery electrodes comprising a spring-mounted support and a counter support for performing asymmetrical pressing.
[0090] FIG. 6 shows a device for producing battery electrodes comprising a divided filling cavity made of two matrices for performing symmetrical pressing.
[0091] FIG. 7 shows an agglomerate of a cathode material in a side view.
DETAILED DESCRIPTION OF THE INVENTION
[0092] The powder mixture comprises—as known from the prior art—the active material of the particular battery electrode, conductivity additives, a polymer binder and/or mixtures of various binders, and possibly additives. The manufacturing of the powder mixture comprising a granulate material is described below.
[0093] In principle, all electrode materials which may be produced in the form of a powder are suitable as active materials. Both active materials for producing cathodes and also active materials for producing anodes may be used. The active materials may be suitable both for producing primary batteries (i.e., non-rechargeable batteries) and also for producing secondary batteries (i.e., rechargeable batteries).
[0094] Examples of suitable active materials for cathodes are manganese dioxide, doped manganese dioxide, copper oxyphosphate, iron phosphate, lithium-cobalt oxides, lithium-nickel-cobalt oxides, boron-doped or aluminum-doped lithium-cobalt oxides or lithium-nickel-cobalt oxides, silver-vanadium oxide, or fluorinated carbon compounds.
[0095] Examples of suitable active materials for anodes are carbon compounds such as graphite, or mesocarbon compounds, and silicon or lithium-titanates.
[0096] The use of active materials having particle sizes >10 μm and <70 μm is especially preferred.
[0097] For example, spherical, potato-shaped, needle-shaped, or plate-shaped graphites, carbon blacks, expanded graphites, or metal powder are suitable as conductivity additives. Expanded graphites are especially suitable.
[0098] The use of conductivity additives having particle sizes >50 nm and <10 μm is especially preferred.
[0099] Fluorinated polymers are preferably used as binders of powder-based electrode materials in lithium batteries because of their high thermal and chemical resistance. Typical polymers are, for example, polytetrafluorethylene (PTFE) or polyvinylidene fluoride (PVDF). In order to achieve the highest possible energy density of the battery—i.e., the highest possible concentration of active materials—the binder content is selected as low as possible. The binder concentration is selected in such a way that the required mechanical stability of the electrode and the adhesion of the powder mixture to the current collector are ensured. Perfluorinated polymers such as polytetrafluorethylene (PTFE) or partially-fluorinated polyolefins such as polyvinylidene difluoride (PVDF) are preferably suitable.
[0100] The use of binders having particle sizes <10 μm is especially preferred.
[0101] Additives are not required for the method described here. However, they may be added to positively influence the properties of the powder mixture, such as the flow behavior, or the properties of the electrodes, such as the porosity. In principle, for example, nanoscale silicon or titanium dioxides are suitable.
[0102] FIGS. 1A through 1C show the compression possibilities of the powder using a plunger-matrix method. The plunger 1 and the matrix 2 are shaped in the desired electrode geometry. Round, rectangular, polygonal, oval, semi-oval, or any other suitable geometries are possible.
[0103] The matrix 2 is filled with the powder mixture. The filling is performed either volumetrically or gravimetrically. The powder is compressed either solely by exerting pressure on the plunger 1 (asymmetrical compression)—as shown in FIG. 1 B—or by simultaneously pressing together matrix 2 and plunger 1 (symmetrical compression), as shown in FIG. 1C . Symmetrical compression is preferred. Forces between 40 and 200 N/cm 2 are used for the compression.
[0104] FIGS. 2A through 2C show the schematic sequence of the production of a battery electrode according to the method described, by first producing two homogeneous pressed parts 3 . A current collector 4 , preferably an etched, embossed, or stamped metallic grid or a grid made of stretched metal, is laid between the pressed parts 3 . In contrast to the prior art cited, the two pressed parts are not glued to the current collector, but rather the two pressed parts 3 are compressed with the grid to form a unit 5 in a pressing procedure.
[0105] The current collector is shown more precisely in FIGS. 5A and 6A . The current collector 4 is formed by a part 4 A to be coated, which is covered by pressed powder mixture, and one or more parts 4 B not to be coated. The part 4 A to be coated is preferably an etched, embossed, or stamped metallic grid or a grid made of stretched metal. The parts 4 B not to be coated are implemented as “contact tabs” or any other suitable contact capability. Electrically conductive contacts to the battery housing or to a bushing of the battery may be produced using these parts 4 b not to be coated, e.g., by welding.
[0106] FIGS. 3A through 3F show a preferred method sequence for producing a battery electrode. Firstly, only half of the powder quantity 6 a which is required for the battery electrode 5 is dosed into a filling cavity 2 —preferably a matrix ( FIG. 3B ). The current collector 4 , preferably an etched, embossed, or stamped metallic grid or grid made of stretched metal, is laid in the matrix 2 ( FIG. 3C ) and the other half of the powder quantity 6 b which is required for the electrode is then dosed into the matrix 2 ( FIG. 3D ). Subsequently, the powder quantity is compressed with the current collector 4 , which is preferably positioned centrally, with the aid of the compression means 1 FIG. 3E and a battery electrode 5 is thus produced FIG. 3F .
[0107] To prevent “sinking” of the current collector 4 into the loose powder mixture 6 , the powder mixture 6 may be precompressed at low pressure by a pressing procedure after the first dosing procedure.
[0108] FIGS. 4A through 4D show a further pressing method according to an embodiment of the invention. The current collector 4 , preferably an etched, embossed, or stamped metallic grid or a grid made of stretched metal, is positioned in the matrix 2 ( FIG. 4A ). The powder quantity 6 required for the electrode is dosed in its entirety into the matrix 2 , half of the powder flowing through the current collector 2 ( FIG. 4B ). The powder quantity 6 is then compressed asymmetrically with the aid of compression means 1 ( FIG. 4C ). After the demolding, the battery electrode 5 is obtained.
[0109] FIG. 5B shows an embodiment of a device 10 for producing a battery electrode, using the asymmetrical pressing method which is described in FIG. 3 or 4 may be performed. The part 4 b of the current collector 4 not to be coated is laid on the spring-mounted support means 7 . A fixing means 8 is laid on the part 4 b of the current collector 4 not to be coated, which lies on the spring-mounted support means 7 , so that the area of the part 4 b of the current collector 4 not to be coated is covered both from above and also from below. The powder 6 to be compressed may either be poured in halfway before the current collector 4 is inserted or even—if the current collector is a grid—may be poured through the current collector 4 .
[0110] Both the support means 7 and also the fixing means 8 may comprise a pin, the pin of the support means 7 being spring-mounted and mounted so it is vertically displaceable.
[0111] During compression of the powder mixture 6 using a plunger 1 , the spring-mounted support 7 is pressed in far enough to correspond to the compression of the powder mixture 6 . This ensures that the part 4 B of the current collector 4 not to be coated always remains positioned in the plane of the current collector 4 and is not bent during the compression of the powder mixture 6 .
[0112] FIG. 6B shows a further embodiment of the device for producing a battery electrode, using which the symmetrical pressing method shown in FIG. 1 c may preferably be performed. A multipart matrix 2 a and 2 b may be used during the pressing procedure. The compression is performed for this purpose using two compression means. The lower plunger la is inserted into the lower matrix 2 a (a). The current collector 4 , preferably an etched, embossed, or stamped metallic grid or grid made of stretched metal, is laid on the lower matrix 2 a in such a way that the parts 4 b of the current collector 4 not to be coated lie on the upper edge of the lower matrix 2 a (b). The upper matrix 2 b is placed on the lower matrix 2 a. The top of the bottom matrix 2 a and the bottom of the top matrix 2 b of the matrices are shaped so that the “tabs” 4 b are enclosed in the mold (c). The closed multipart matrix 2 is filled with the powder mixture 6 (d). The upper plunger 1 b is subsequently put on and the powder mixture 6 is symmetrically compressed by moving the upper and lower plungers 1 a and 1 b toward one another under force (e). Finally, the plungers 1 a and 1 b are drawn back and the upper part of the matrix 2 b is removed. The pressed battery electrode 5 may be removed. Picture (f) shows the finished battery electrode lying on the lower matrix 2 a of the multipart matrix 2 .
[0113] The above described procedures make the production of electrodes up to a thickness of 500 μm possible.
[0114] The manufacturing of the powder mixture is described below.
[0115] Fine disperse graphite (for example GNP 6 , RMC Remacon GmbH) and acetylene carbon (for example P50uv, SKW Stickstoffwerke Priesterwitz GmbH) in the relation black carbon 69 weight % and graphite 31 weight % are dry homogenized by an inversion mixture apparatus using mixture additives.
[0116] For the manufacturing of the binder suspension (first suspension) the polymer binder (for example PvdF Kynar 741, Atofina Deutschland GmbH) with a relation of 5.5 weight % (this means the fraction of the solid mass of the binder related to the whole electrode mass) is suspended with a high shear gradient (that means high revolution speed) within 400 ml heptan as a inert solvent using a toothed ring disperser.
[0117] For the production of a homogeneous mixture of binder and additive the additive mixture is slowly added to the binder suspension in order to produce a homogenous intermediate suspension. At the end the additive mixture is contained by a fraction of 6.5 weight % within the electrode mass. The viscosity should be low. If necessary, up to 100 ml of solvent has to be added as an additional dose.
[0118] The intermediate suspension is then used in order to slowly suspend 88 weight % (this means the solid mass fraction of the active material related to the whole electrode mass) of active material (this means the solid mass fraction of the active material related to the whole electrode mass). Preferably Manganese Dioxide as active material is used. After that, the solvent is distilled off during rotating. During distilling a granulation occurs. As a result, a coarse granulate material with spherical granulate particles is formed. The coarse granulate material is then dried in vacuum (pressure below 100 mbar) at a temperature of 100° C. for 8 hours.
[0119] The cathode material is then sieved with a sieve having a mesh size of 0.315 mm to a final grain size of about 300 μm maximum. This cathode material may then be further processed by an automatic press.
[0120] The adhesion of the binder particles to the active material particles is shown in FIG. 7 . Two active material particles 100 agglomerate with two binder particles 200 forming a granulate grain. The binder particles 200 are not diluted within a solvent but just adsorbed at the surface of the active material particles 100 .
[0121] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teaching. The disclosed examples and embodiments are presented for purposes of illustration only. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention. | A method for manufacturing of a powder mixture for a battery electrode that includes suspending of particles of at least one binder within an inert solvent producing a first suspension, slowly suspending of particles of an active material within the first suspension producing a second suspension, drying of the second suspension producing a granulate material. Further relates to a respective powder mixture, an electrode and a method of manufacturing the electrode. | 1 |
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates, in general, to sewing machines and, in particular, to a new and useful sewing machine having a lifting and feeding mechanism which includes an arrangement for insuring that the relative velocity of the top feed foot reduces substantially during its movement toward its touch-down on the material which is being sewn.
In a prior art top feeding device of this class (U.S. Pat. No. 3,570,427), a transmitting rocker arm for the lifting drive of the top feed foot is mounted on a support element of the support system in order for the top feed foot to be carried along in the upward direction during the lifting of the support system.
In this device, the lifting drive has an essentially sinusoidal movement pattern. As a result of this, the top feed foot reaches its maximum velocity upon touching down on the fabric to be sewn, so that vibrations may occur at high sewing machine speeds.
The present invention provides a movement pattern of the top feed foot in the top feeding device, so that the relative velocity of the top feed foot will reduce substantially during the touch down phase.
This task is achieved in an top feeding device for sewing machines which includes a sewing machine main drive shaft connected to a connecting rod mechanism for moving a transmitting rocker arm to achieve a lowering and lifting movement of a top feed foot and a material presser foot on a support of the sewing machine wherein a spring is provided biasing the presser foot downwardly. The movement is provided such that the feed foot touches down on the material to be sewn and feeds the material to a reciprocating swinging needle in order to have both the feed drive and the lifting drive moving the top feed foot so that its velocity decreases during is touch-down on the material. A drive mechanism is provided between the transmitting rocker arm and the presser foot. The rocker arm is provided with a common pivot. The drive mechanism includes a pair of first and second connecting rods mounted on the support and connected to the common pivot of the rocker arm.
The vertical component of movement acting on the top feed foot during its touch-down phase is reduced substantially by the device according to the present invention compared with the normally sinusoidal movement pattern, while the vertical movement component is increased outside the touch-down phase. The duration of the touch-down phase of the top feed foot is thus increased and the forces to be absorbed by the compression springs are reduced.
Even though devices for retarding the touch-down and lift-off movements of the top feed foot in top feeding devices of another basic design are known, e.g., from U.S. Pat. No. 3,935,825, these devices are of a very complicated design compared with the invention and they also require the basic design of the top feeding device to be different.
Accordingly, an object of the invention is to provide an improved transmission mechanism for insuring that the top feed foot of the feeding device is moved with a decreasing velocity as it approaches the touch-down on the material.
A further object of the invention is to provide a sewing machine which is simple in design, rugged in construction and economical to manufacture.
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 specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a partially cut-away side view of a sewing machine having a top feed device constructed in accordance with the invention;
FIG. 2 is a schematic perspective representation of the driving part for the top feeding device;
FIG. 3 is a partially cut-away representation of the transmitting elements for the top feed foot shown on a larger scale; and
FIG. 4 shows a partially cut-away side view of the parts shown in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, the invention comprises a sewing machine, whose housing accommodates a presser bar 2 carrying a presser foot 1 and a needle bar 4 mounted in a needle bar holder 3, where the thread-guiding needle 5 of the needle bar cooperates with a shuttle (not shown). To feed the layers of fabric to be joined together, the sewing machine has a top feed foot 6, which cooperates with a lower feed dog (not shown).
The housing of the sewing machine also accommodates a main shaft 7 (FIG. 2) driven in a known manner, which drives the needle bar 4 via a crank 8 and a connecting rod 9. The connecting rod 9 is mounted on a pin 10 fastened in the crank 8.
An intermediate member 11 is also arranged on the pin 10, and the intermediate member is connected to a pin 12, which is mounted rotatably in the housing in parallel to the main shaft 7 and is fastened on an eccentric 13. The eccentric is embraced by an eccentric rod 14, which is connected to an angle lever 15, which consists of two lever arms 15a, 15b which are fastened to a shaft 15c mounted in a projection of the housing. The lever arm 15b of the angle lever 15 (FIG. 1) is connected via a first lift connecting rod 16 to a common connecting point or pin 17, which is carried by a rocker arm 18. The rocker arm 18 is mounted on a pin 19, which is fastened to a support element 20. The support element 20 is fastened to a rod 21, which is part of a support system 23. This system 23 is fastened in the housing of the sewing machine and carries, next to the vertically movable rod 21, the likewise vertically movable presser bar 2. A more detailed description of the function of the support system 23, including its connection to the two rods 2 and 21, is contained in Patent Application PCT EP 88/00414.
A second lift connecting rod 28 (FIG. 1) is mounted rotatably on a pin 17, and the other end of the second lift connecting rod 28 is hinged to a holder 29 for the top feed foot 6. The support element 20 also carries a pin 30, on which a telescopic bar 31, which is also connected to the holder 29 via a pivot pin 32, is mounted (FIGS. 1 and 3).
The top feed foot 6 is driven to perform its feeding movement by a stitch length control mechanism 40 (FIG. 2), which is connected to an eccentric 41 fastened on the main shaft 7. The stitch length control mechanism 40 has a control shaft 42 that is mounted in the housing shaft and is rigidly connected to a bracket 43, between the arms of which another bracket 44 is mounted rotatably via a pin 45. The arms of the bracket 44 are connected by a bolt 46, to which an eccentric rod 47 is hinged. The eccentric 41, which is embraced by the eccentric rod 47, forces the bolt 46 to perform swiveling movements about the pin 45.
One end of a connecting rod 49 acts on the bolt 46, and its other end is hinged to a lever arm 51, which is fastened at one end of a rocking shaft 52 mounted in parallel to the main shaft 7 in the housing. A lever arm 53 is connected to the other end of the rocking shaft 52 and the lever arm 53 acts on a rocking lever 55 via a connecting rod 54. The rocking lever 55 is fastened on a rocking shaft 56 mounted in the projection of the housing (FIG. 1), and the rocking shaft 56 carries another rocking lever 57, which is connected to the pin 32 of the holder 29 via a connecting rod 58.
A lever arm 60, which is connected to a crank 63 fastened to a control shaft 62 via a connecting rod 61, is fastened on the control arm 42 (FIG. 2) of the stitch length control mechanism 40.
A control crank 64 is clamped on the control shaft 62 mounted in the housing and is connected to an intermediate shaft 67 mounted in the housing via an intermediate member 65 and another control crank 66. A lever 68 is fastened to the intermediate shaft 67. The lever 68 is connected via a ball-headed drawbar 69 to one end of a rocking lever 70, which can be pivoted about an axis 71 forming an integral part of the housing. The still free end of the rocking lever 70 has a spherical projection 72 and reaches into a control cam 73 of a setting wheel 74 that can be locked and is arranged on an axis 75 rigidly integrated in the housing. The control cam 73 in the setting wheel 74 extends in a spiral pattern toward the axis 75 of the wheel, so that stitch lengths of, e.g., 1 to 6 mm can be selected on the top feed foot 6. A spring 76 embracing the intermediate shaft 67 and fastened with one of its ends in the housing keeps the projection 72 of the rocking lever 70 steadily in contact with one of the side walls of the control cam 73.
The control shaft 62 is connected to the lower feed dog (not shown) in the known manner, so that when the position of the setting wheel 74 is changed, both the top feed foot 6 and the lower feed dog are adjusted synchronously.
The telescopic bar 31 arranged between the support element 20 (FIGS. 3 and 4) and the holder 29 for the top feed foot 6 is subdivided into an upper fork 80 and a lower fork 81. The lower fork 81 is connected to a bolt section 82 and the upper fork 80 is connected to a sleeve section 83, which are pushed into one another and held together by a screw 84 screwed into the bolt section 82. A plate spring 85 is inserted between the head of the screw 84 and the upper fork 80, and the spring plate assembly 86 is inserted between the sleeve section 83 and the lower fork 81. The pretension of the plate spring assembly 86 can be changed by means of a nut 87 screwed on the threaded sleeve section 83.
The device operates as follows:
The amount of feed of the top feed foot 6 (FIGS. 1 and 2) is set by rotating the setting wheel 74, as a result of which the control cam 73 will rotate the intermediate shaft 67 correspondingly via the rocking lever 70.
The intermediate shaft 67 now adjusts the control shaft 62 via the intermediate member 65 and the control shaft 42 via the connecting rod 61 and the lever arm 60. It is achieved through this arrangement that when the setting wheel 74 is adjusted, the feed setting of the top feed foot 6 is changed synchronously with the feed setting of the lower feed dog via the control shaft 62.
The movement derived from the eccentric 41 is transmitted via the drive mechanism consisting of eccentric rod 47, bolt 46, connecting rod 49, lever arm 51, rocking shaft 52, lever arm 53, connecting rod 54, rocking levers 55 and 57, connecting rod 58, pivot pin 32, and holder 29 to the top feed foot 6, which will therefore perform a corresponding feeding movement.
Synchronously with the feeding movement of the top feed foot 6, the movement, which is derived from the eccentric 13 is transmitted as a lifting movement to the holder 29 and consequently to the top feed foot 6 via the drive mechanism comprising the eccentric rod 14, the angle lever 15, the first lift connecting rod 16, the pin or common pivot 17, and the second lift connecting rod 28. Consequently, the top feed foot moves up and down in the correct cadence of its feeding movement.
When the angle lever 15 and the first lift connecting rod 16 swivel out (see FIG. 3), the rocker arm 18 is moving between the positions (A, B) in a working zone that is selected so that the up and down movement at the bolt 17 is transmitted relatively slowly in the area of position (A), but relatively rapidly in the area of position (B). The lifting movement transmitted by the first lift connecting rod 16 to the holder 29 is decelerated by the rocker arm 18 in the area between the positions (M' and A') and accelerated in the area between the positions (M' and B'). Correspondingly, the top feed foot 6 is moving slowly in the area of touch-down on the fabric to be sewn, but rapidly in the lift-off area, so that chatter effects during the touch-down on the fabric to be sewn are avoided practically completely.
The telescopic bar 31 becomes shorter during the operation while the spring tension of the spring plate assembly 86 increases, and it recovers its original length on release. Thus, after touch-down of the top feed foot 6 on the fabric to be sewn, the spring plate assembly 86 absorbs both the residual lift of the top feed foot 6 and the lifting movement of the lower feed dog via the needle plate.
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 material top feeding device for sewing machines includes an arrangement to reduce the movement component of the top feed foot during its phase of touch-down. For this purpose, the connecting rod drive mechanism includes of a pair of connecting rods, whose connecting joint is fastened rotatably on a rocker arm mounted on the support element. The mounting of the rocker arm is arranged so that in the area of touch-down of the top feed foot, the rocker arm extends essentially in parallel to the connecting rod arranged between it and the top feed foot. | 3 |
FIELD OF THE INVENTION
The invention relates to a wirelessly operated motorized shade. Specifically, the invention relates to a wirelessly operated motorized shade having an improved antenna arrangement and/or antenna cable connection.
BACKGROUND OF THE INVENTION
A roller shade is a rectangular panel of fabric, or other material, that is attached to a cylindrical, rotating tube. The shade tube is mounted near the header of a window such that the shade rolls up upon itself as the shade tube rotates in one direction, and rolls down to cover a desired portion of the window when the shade tube is rotated in the opposite direction.
Rotation of the roller shade is accomplished with an electric motor that is directly coupled to the shade tube. Recently-developed battery-powered roller shades provide installation flexibility by removing the requirement to connect the motor and control electronics to facility power. The batteries for these roller shades are typically mounted within, above, or adjacent to the shade mounting bracket, headrail or fascia. The motor may be located inside or outside the shade tube, is fixed to the roller shade support and is connected to a simple switch, or, in more sophisticated applications, to a radio frequency (RF) based system that controls the activation of the motor and the rotation of the shade tube. These RF based systems typically need an antenna to transmit and receive RF signals and associated cabling to connect the antenna to a controller. Unfortunately, these RF based systems suffer from many drawbacks, including, for example, poor performance, need for a large area for an antenna, increased costs, increased complexity, and/or the like for the antenna and cabling.
SUMMARY OF THE INVENTION
Aspects of the invention advantageously provide a motorized roller shade that includes a shade tube, including an outer surface upon which a shade is attached, an inner surface defining an inner cavity and two end portions, a motor/controller unit, disposed within the shade tube inner cavity and mechanically coupled to the shade tube inner surface, including a support shaft configured to attach to a mounting bracket, a DC motor having an output shaft coupled to the support shaft such that the output shaft and the support shaft do not rotate when the support shaft is attached to the mounting bracket, a power supply unit, electrically coupled to the motor/controller unit, disposed within the shade tube inner cavity and mechanically coupled to the shade tube inner surface, including a support shaft attachable to a mounting bracket, a wireless receiver coupled to the motor/controller unit to receive wireless signals, and an antenna arranged on or in at least one of the two end portions.
Additional aspects of the invention advantageously provide a motorized roller shade that includes a shade tube including an outer surface upon which a shade is attached, an inner surface defining an inner cavity and two end portions, a motor/controller unit including a support shaft configured to attach to a mounting bracket, a DC motor having an output shaft coupled to the support shaft, a power supply unit, electrically coupled to the motor/controller unit, disposed within the shade tube inner cavity and mechanically coupled to the shade tube inner surface, including a support shaft attachable to a mounting bracket, a wireless receiver coupled to the motor/controller unit to receive wireless signals, and an antenna arranged on or in the motorized roller shade and a coupling that couples the antenna to said wireless receiver.
There has thus been outlined, rather broadly, certain aspects of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional aspects of the invention that will be described below 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 aspects in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, 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 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 invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an isometric view of a motorized roller shade assembly, in accordance with aspects of the invention.
FIG. 2 depicts an isometric internal view of the motorized roller shade assembly depicted in FIG. 1 .
FIG. 3 depicts a partial isometric view of the motorized roller shade assembly depicted in FIG. 2 .
FIG. 4 depicts a partial isometric view of the motorized roller shade assembly depicted in FIG. 1 .
FIG. 5 depicts a partial isometric view of another aspect of the motorized roller shade assembly.
FIG. 6 depicts a partial isometric view of yet another aspect of the motorized roller shade assembly.
FIG. 7 depicts a cross section view of endcap and antenna connections of the motorized roller shade assembly depicted in FIG. 1 .
FIG. 8 depicts a partial cross section view of the endcap and antenna connections of the motorized roller shade assembly depicted in FIG. 7 .
DETAILED DESCRIPTION
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. The term “shade” as used herein describes any flexible material, such as a shade, a curtain, a screen, etc., that can be deployed from, and retrieved onto, a storage tube or similar structure.
Aspects of the invention provide a remote controlled motorized roller shade in which the batteries, DC gear motor, control circuitry may be entirely contained within a shade tube that may be supported by bearings. Two support shafts may be attached to respective mounting brackets, and the bearings rotatably couple the shade tube to each support shaft. The output shaft of the DC gear motor may be fixed to one of the support shafts, while the DC gear motor housing is mechanically coupled to the shade tube. Accordingly, operation of the DC gear motor causes the motor housing to rotate about the fixed DC gear motor output shaft, which causes the shade tube to rotate about the fixed DC gear motor output shaft as well. The control circuitry is operated by the user using a radio frequency remote control. Control signals from the remote control are received by the control circuitry through an antenna.
The antenna is arranged on the remote controlled motorized roller shade. In one aspect, the antenna may be arranged on an end of the roller shaft. In a further aspect, the antenna may be a fractal antenna. In another aspect, the antenna may be connected to the control circuitry with a coaxial cable through a connector. The antenna configuration and/or coaxial cable configuration improves performance, reduces the size of the components, reduces costs, reduces complexity, and/or the like.
FIG. 1 depicts an isometric view of a motorized roller shade assembly, in accordance with aspects of the invention. In particular, FIG. 1 shows a motorized roller shade assembly 1 that may be mounted near a top portion of a window, door, or the like. The motorized roller shade assembly 1 may be held using mounting brackets 3 . Generally, the motorized roller shade assembly 1 includes a shade 32 and a motorized tube assembly 8 . In one aspect, the motorized roller shade assembly 1 may also include a bottom bar 2 attached to the bottom of the shade 32 . The bottom bar 2 may provide an end-of-travel stop or other function.
The motorized roller shade assembly 1 may be supported by shafts 6 that may be positioned and retained by openings 5 in the mounting brackets 3 . The upper or first end of the shade material is secured to the storage roll 8 by means known in the art. In some aspects, all of the components necessary to power and control the operation of the motorized roller shade assembly 1 may be advantageously located on or within motorized tube assembly 8 (Shown in FIG. 2 ).
The motorized roller shade assembly 1 also includes an antenna 4 so that control signals may be received in the motorized roller shade assembly 1 and/or transmitted from the motorized roller shade assembly 1 . The antenna 4 may be arranged anywhere on or in the motorized roller shade assembly 1 . In particular, the antenna 4 may be arranged on an outside surface of the motorized roller shade assembly 1 to improve reception and/or transmission performance. Furthermore, the antenna 4 may be arranged on an outside end surface of the motorized roller shade assembly 1 to further improve reception and/or transmission performance. Additionally, the antenna may be arranged on a Printed Circuit Board (PCB) or wafer 14 . Arranging the antenna 4 on a PCB 14 makes manufacturing less complex and less expensive.
FIG. 2 depicts a partial internal isometric view of the motorized roller shade assembly depicted in FIG. 1 . As shown in FIG. 2 , internal to the storage roll 8 is a motor assembly 10 , a motor controller and RF receiver 11 , a power supply 12 , counterbalance springs 13 and end caps 7 which may hold and position the shafts 6 . Note that other arrangements of components may also be used and is within the scope of spirit of the invention.
The end cap 7 closest to the motor may include the PCB 14 or similar mounting structure. The PCB 14 may include a substantially flat surface for the antenna 4 . The antenna 4 may be located a distance from the receiver and motor control 11 . However, the antenna 4 may be arranged on any surface of the motorized roller shade assembly 1 .
FIG. 3 depicts a partial isometric view of the motorized roller shade assembly depicted in FIG. 2 . In particular, FIG. 3 shows details of the antenna 4 . In particular, the antenna 4 may take the form of a fractal antenna or similar antenna structure that uses a fractal and/or self-similar design to maximize the length, or increase the perimeter that may receive or transmit RF signals within a given total surface area or volume. Similarly, the antenna may be a multilevel and space filling curve that includes a repetition of a motif over two or more scale sizes. The use of a fractal antenna allows for a compact multiband or wideband operation with improved performance.
The RF signals received by the antenna 4 from a user transmitter (not shown) or transmitted from the antenna 4 are carried by wiring to the receiver and motor control 11 . The wiring may be a coaxial cable 9 .
FIG. 4 depicts a partial isometric view of the motorized roller shade assembly depicted in FIG. 3 . More specifically, FIG. 4 shows details of a particular aspect of the antenna 4 . In this particular aspect, the antenna 4 may be implemented as a fourth iteration von Koch design fractal antenna. It has been found that the fourth iteration von Koch design fractal antenna has superior qualities. However, other antennas having a smaller size with the receiving capability of larger antennas are also contemplated including without limitation, other fractal antenna configurations, loop antenna configurations, space filling curve shrunken fractal helix antenna configurations, or the like.
FIG. 5 depicts a partial isometric view of another aspect of the motorized roller shade assembly. In particular, FIG. 5 shows an aspect of the antenna 4 arranged in or on PCB 14 that takes the form of a partial circle arranged along an outside edge of the end cap 7 . As shown in FIG. 5 , the coaxial cable 9 conductor 20 terminates with a wiring connection that extends through the PCB 14 and is electrically connected to the antenna 4 .
FIG. 6 depicts a partial isometric view of yet another aspect of the motorized roller shade assembly. In particular, FIG. 6 shows an aspect of the antenna 4 arranged in or on PCB 14 that takes the form of a spiral. As shown in FIG. 6 , the coaxial cable 9 conductor 20 terminates with a wiring connection that extends through the PCB 14 and is electrically connected to the antenna 4 .
FIG. 7 depicts a cross section view of endcap and antenna connections of the motorized roller shade assembly depicted in FIG. 3 ; and FIG. 8 depicts a partial cross section view of the endcap and antenna connections of the motorized roller shade assembly depicted in FIG. 7 . In particular, FIGS. 7 and 8 show the connection of the wiring between the antenna 4 and the motorized roller shade assembly 1 . The wiring may be implemented as a cable; and more specifically may be implemented as a coaxial cable 9 .
Regarding the connection, the coaxial cable 9 may be configured so that an outer insulator 17 is stripped away or removed at an end of the coaxial cable 9 adjacent to the PCB 14 . Further, a braid 18 of the coaxial cable 9 may be trimmed to expose a center insulator 19 at the end of the coaxial cable 9 adjacent to the PCB 14 . The center insulator 19 then may be trimmed to slightly less than the thickness of the PCB 14 .
The coaxial cable 9 with this construction may be inserted into a hole 23 in the PCB 14 that is centered between two pads 15 and 21 (one on the top layer and one on the bottom layer). The two pads 15 and 21 may not be plated through the hole 23 in the PCB 14 . The braid 18 may be soldered to pad 15 so as to form a solder connection 16 between the pad 15 and the braid 18 . The solder 16 may make an electrical connection between the pad 15 and the braid 18 . The solder connection 16 may also serve as a mechanical fastener for fastening the cable 9 to the PCB board 14 .
The construction of the solder connection 16 to the pad 15 relieves strain associated with the fragile center conductor 20 and reduces the chance of damage. The PCB hole 23 may be sized to only allow the center insulator 19 inside the PCB board 14 .
It should be noted that in this aspect, the size of the common hole is critical to the performance of this construction/method. The braid 18 (outer conductor) should not be allowed to enter into the hole 23 . Additionally, the center insulator 19 may be trimmed so as to not protrude beyond the bottom layer 21 . However, other configurations are contemplated.
The center conductor 20 may be soldered to the bottom layer 21 and trimmed. Note the insulator 19 can be trimmed to expose the center conductor 20 below the surface near the bottom layer 21 . In this alternate fashion, the center conductor 20 may be soldered 16 to the bottom layer 21 and then trimmed very flush to the bottom layer 21 .
The connection of the antenna coaxial cable 9 to the PCB 14 can be formed onto or incorporated into a printed circuit board (PCB) 14 placed in the end cap 7 of the storage roll 8 . This configuration eliminates the need for a more costly coaxial connector on the cable and costly coaxial socket on the PCB 14 . Additionally, the invention reduces the size of the attachment to nearly the diameter of the incident coaxial cable. The invention relieves strain associated with the cable directly at the PCB 14 , allowing flexing immediately above the PCB 14 surface. With a connector of the invention, the strain relief occurs at the back of the connector, thus not allowing the cable to flex at the PCB itself.
The motorized roller shade assembly 1 may include other components such as an electrical power connector that includes a terminal that couples to a power supply unit, and power cables that may connect to the circuit board(s) located within the circuit board housing.
Two circuit boards may be mounted within the circuit board housing in an orthogonal relationship. Circuit boards generally include all of the supporting circuitry and electronic components necessary to sense and control the operation of the motor, manage and/or condition the power provided by the power supply unit, etc., including, for example, a controller or microcontroller, memory, a wireless receiver, etc. In one embodiment, the microcontroller is a Microchip 8-bit microcontroller, such as the PIC18F25K20, while the wireless receiver is a Micrel QwikRadio® receiver, such as the MICRF219. The microcontroller may be coupled to the wireless receiver using a local processor bus, a serial bus, a serial peripheral interface, etc. In another embodiment, the wireless receiver and microcontroller may be integrated into a single chip, such as, for example, the Zensys ZW0201 Z-Wave Single Chip, etc.
In another embodiment, a wireless transmitter is also provided, and information relating to the status, performance, etc., of the motorized roller shade may be transmitted periodically to a wireless diagnostic device, or, preferably, in response to a specific query from the wireless diagnostic device. In one embodiment, the wireless transmitter is a Micrel QwikRadio® transmitter, such as the MICRF102. A wireless transceiver, in which the wireless transmitter and receiver are combined into a single component, may also be included, and in one embodiment, the wireless transceiver is a Micrel RadioWire® transceiver, such as the MICRF506. In another embodiment, the wireless transceiver and microcontroller may be integrated into a single module, such as, for example, the Zensys ZM3102 Z-Wave Module, etc. The functionality of the microcontroller, as it relates to the operation of the motorized roller shade 320 , is discussed in more detail below.
The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention. | A motorized roller shade includes a shade tube, including an outer surface upon which a shade is attached, an inner surface defining an inner cavity and two end portions, a motor/controller unit, disposed within the shade tube inner cavity and mechanically coupled to the shade tube inner surface, including a support shaft configured to attach to a mounting bracket, and a DC motor having an output shaft coupled to the support shaft such that the output shaft and the support shaft do not rotate when the support shaft is attached to the mounting bracket. A wireless receiver is coupled to the motor/controller unit to receive wireless signals and an antenna is arranged on or in at least one of the two end portions. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of German Patent Application No. 102011115499.3, filed Aug. 29, 2011, entitled ÜBERGANGSKANAL EINE TURBOAGGREGATS, the specification of which is incorporated herein in its entirety.
TECHNICAL FIELD
[0002] The invention concerns a transition channel between components of a turbine unit, as well as a turbine unit and a jet engine, especially an aircraft engine, with such a transition channel.
BACKGROUND
[0003] A transition channel, such as can be arranged in particular between a high-pressure turbine and a low-pressure turbine or—when the turbine has a three-piece design—between high and medium-pressure turbine and/or medium and low-pressure turbine, determines the flow to the first rotor of the downstream turbine. The transition or diversion channel (“turning mid turbine frame”, TMTF) generally guides the flow in annular or envelope fashion from an upstream flow cross section to a downstream flow cross section that has a rather large radial distance from the turbine axis. Also in multistage compressors, the transition channel directs the flow in similar fashion from an upstream to a downstream flow cross section.
[0004] For greater rigidity, such a transition channel generally has identical support ribs distributed about the periphery, which also bring about a diversion of the flow, especially in the circumferential or peripheral direction, in order to provide a flow to the blades of a first rotor of the downstream turbine or compressor stage.
[0005] These support ribs generally have a large relative thickness, i.e., a ratio of profile thickness to chord length, and/or a small blade height ratio, i.e., a ratio of blade height to chord length. The comparatively large relative thickness or small relative height of the support ribs can be required in particular for static strength.
[0006] Such a geometry of the support ribs, however, leads to intense secondary flows. Marginal areas are formed with an eddy flow, which can dominate the flow pattern. Such strong three-dimensional secondary flows are detrimental to the main flow; in particular, they may limit the maximum possible deflection at hub and housing and lead to energy transfer losses and excitation of the first rotor blade series of the downstream turbine, which can result in particular in higher noise levels for the turbine. Furthermore, the much smaller numbers of blades as compared to conventional stator geometry can result in aerodynamic excitation of the following rotor blades with fundamental modes, so-called “engine orders”, in the working range of the turbine unit.
[0007] A gas turbine with an annular transition channel from a high-pressure turbine section to a low-pressure turbine section is known from US 2010/0040462 A1, wherein the transition channel has guide vanes that extend between an outer envelope surface and an inner envelope surface of the transition channel and are distributed over the circumferential direction. The guide vanes have a wing profile. To minimize a “rolloff” of the flow in the transition from a horizontal to a radially ascending flow, the inner envelope surface has a particular curved shape.
[0008] A need therefore exists, for improved flow in a transition channel of this kind
SUMMARY AND DESCRIPTION
[0009] The problem is solved according to the invention by a transition channel with the features as described and claimed herein, a turbine unit with the features as described and claimed herein and an engine with the features as described and claimed herein. Advantageous configurations and modifications of the invention are indicated in the particular subclaims.
[0010] The invention is based on the knowledge that eddies, flow losses and/or deflection constrictions can be reduced if additional deflection elements are arranged between the support ribs, which are likewise profiled for deflection of the flow, that are configured as narrower and/or shorter flow dividers as compared to the support ribs.
[0011] Accordingly, the present invention proposes a transition channel for a turbine unit, especially a gas turbine unit, with at least two components, wherein the transition channel is designed and oriented as a flow channel, especially a stationary one, from one component of a first pressure to a component of second pressure. The transition channel can have, in particular, an annular cross section and/or one whose axial shape is distant on the whole from one axis of the turbine unit.
[0012] The first pressure can be a higher one and the second pressure a lower one, if the transition channel is arranged between two turbines or turbine stages. Likewise, on the contrary, the first pressure can be a lower one and the second pressure a higher one, if the transition channel is arranged between two compressors or compressor stages, which can be components of a turbine unit in the sense of the present invention, such as turbines or turbine stages.
[0013] Support ribs extending between envelope surfaces of the transition channel have a profile that is designed and oriented for the axial, radial and/or circumferential deflecting of a flow from an inlet cross section to an outlet cross section of the transition channel.
[0014] One or more flow splitter blades are arranged between at least two, and preferably between all support ribs; preferably the same number of flow splitter blades are arranged between all support ribs and/or the flow splitter blades are spaced equidistant from each other and/or the support ribs.
[0015] From a first perspective of the invention, one or more and especially all of these flow splitter blades have a smaller relative profile thickness than the support ribs. By a relative profile thickness is meant, in particular, the quotient of the maximum or average profile thickness to the profile chord length.
[0016] Thanks to the integration of such slimmer flow splitter blades as tandem blades, it is possible to reduce parasite secondary flows, since now the slimmer tandem blades take over part of the deflection work.
[0017] It is proven to be especially advantageous for a relative profile thickness of the flow splitter blades to be at most 15%, preferably at most 10%.
[0018] Moreover, it has proven to be advantageous for the flow splitter blades to be arranged in a rear region of the support ribs, looking in the axial direction. In particular, it has proven to be advantageous for the front edges of some or all of the flow splitter blades, looking in the axial direction, to be distant by at least 25%, preferably at least 30%, of an axial design depth of the support ribs, from the furthermost front edge of the support ribs. According to the experience of the inventor, the flow splitter blades can fulfill their task especially well if an axial design depth of the flow splitter blades is less than an axial design depth of the support ribs; but the axial design depth of the flow splitter blades should be at least 30% of the axial design depth of the support ribs.
[0019] The support ribs can already achieve a substantial deflection of the flow and an increasing of the flow velocity in the region of the front 50% of the axial design depth of the long support ribs, likewise acting as deflection blades. If, now, one integrates a tandem blade in the rear region of the design depth of the support ribs in the design of a slender, preferably short flow splitter blade or vane, even higher velocities or Mach numbers can be handled with no problem upstream from the tandem blades.
[0020] Furthermore, it has proven to be especially advantageous for rear edges of the flow splitter blades to project beyond rear edges of the support ribs, looking in the axial direction, this projection in the axial direction being preferably at most 25% of an axial design depth of the support ribs. Thanks to such a design, the effective length of the flow deflection can be increased. Optionally, the flow deflection zone can also be extended to just prior to the first rotating blade series of the downstream component.
[0021] An advantageous flow deflection can often be accomplished already by arranging precisely one flow splitter blade between two support ribs. However, it is also possible to arrange two or more flow splitter blades between every two support ribs. Thanks to the deflection at the transition channel, the off-design requirements on the flow splitter blades are relatively slight, since the bulk of the unwanted flow is captured already by the long support ribs. The number of flow splitter blades is limited essentially by the maximum allowable partitioning of the transition channel for adequate off-design capability. Thus, the maximum allowable partitioning depends on the boundary conditions.
[0022] Most of the application cases will be covered if one to five flow splitter blades are arranged between the support ribs. Preferably, the total number of support ribs and flow splitter blades taken together is chosen such that excitations of fundamental modes of the rotor blades in the operating range by perturbation harmonics of the transition channel are prevented or reduced.
[0023] The present invention enables an improvement of the flow thanks to a partial division of functions: the number, shape and arrangement of the long and heavy support ribs is dictated by the supporting and the initial upstream flow deflection, as well as any supply lines to be accommodated in the support ribs, while the slender flow splitter blades take over the largest possible portion of the downstream flow deflection. Thus, short, light and highly efficient designs with rather high deflection become possible. The nonuniformity of the flow against the downstream component, the engine noise, and the exciting of the later rotor blades in the critical frequency range are reduced and the lifetime of the blading is increased.
[0024] It should be pointed out that the flow splitter blades, as well as the support ribs, preferably have a two or three-dimensional curved wing profile. Wing profiles have proven themselves in general and especially in the present application as effective profile shapes for deflection of flows.
[0025] From another perspective of the present invention, an axial design depth or a profile chord length of the flow splitter blades is shorter than an axial design depth or profile chord length of the support ribs. Thanks to the integration of the short flow splitter blades, which correspondingly have a larger blade height ratio, it is possible to largely dissipate parasite secondary flows, since now the shorter tandem blades take over some of the deflection task. This perspective can be combined with the above described perspective of the invention and its modifications.
[0026] According to another perspective of the present invention, a turbine unit is proposed, especially a gas turbine unit, with a first component and a second component, wherein the first component is associated with a different, especially a higher pressure than the second component, wherein one exit cross section of the first component has a smaller radial dimension than an entry cross section of the second component, wherein a transition channel is provided as a stationary flow channel between the first and the second component, and wherein the transition channel is configured according to one of the above described embodiments. It is especially advantageous in a two-piece construction of the turbine unit for the first component to be a high-pressure turbine and in a three-piece construction of the turbine unit for the first component to be a high or medium-pressure turbine, and the second component to be a low-pressure turbine, or optionally a medium-pressure turbine in a three-piece construction. Likewise, the first and second component of a turbine unit according to the invention can also be a compressor or a compressor stage, in which case the first component is associated with a lower pressure than the second component, and one exit cross section of the first component can have a larger radial dimension than an entry cross section of the second component.
[0027] According to another perspective of the invention, a jet engine is proposed, especially an aircraft engine, which is outfitted with a turbine unit as described above.
[0028] Embodiments of the present invention can reduce losses of a turbine unit, improve the flow to the second component and/or reduce or prevent critical excitations of a downstream rotor by appropriate choice of the total number of support ribs and flow splitter blades.
[0029] In one preferred embodiment, the transition channel is not annular, but has a radially inner and/or outer nonround envelope surface. This makes provision for the more thickly engineered support ribs in the oncoming flow direction, according to the rule of surfaces, by locally enlarging the envelope surface in the area of their connection to it.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Further advantages, features and details of the invention will emerge from the following description of a sample embodiment and also by means of the drawings, in which the same or functionally identical elements are given the same reference numbers. There are shown, partly schematized:
[0031] FIG. 1 is an axial section view (top) and a partial developed view (bottom) of a transition channel according to one sample embodiment of the present invention; and
[0032] FIG. 2 is a developed view corresponding to the lower region in FIG. 1 of a transition channel in a modification of the present invention.
DETAILED DESCRIPTION
[0033] FIG. 1 shows, as an example, a transition channel between two components of a turbine, hereinafter turbine components, in axial half-section and median section (top part of the drawing) and in a planar developed view or profile section (bottom part of the drawing).
[0034] According to the representation in FIG. 1 , a flow process between a high-pressure turbine 10 and a low-pressure turbine 12 is determined by a transition channel 14 . The flow process is indicated by an arrow 16 .
[0035] The transition channel 14 has an inner wall or envelope surface 18 and an outer wall or envelope surface 20 , which together define an annular cross section. In particular, an entry cross section 22 is defined at the start of the transition channel 14 and an exit cross section 24 at the outlet of the transition channel 14 . It should be noted that the transition channel 14 is configured stationary with respect to the turbine axis A or an otherwise not represented turbine housing, while the high-pressure turbine 10 and the low-pressure turbine 12 have rotors with rotating blades that turn in a direction of rotation R about the turbine axis A. In the figure, one rotating blade 13 of a first stage of the low-pressure turbine 12 is indicated.
[0036] As can be seen from the figure, the entry cross section 22 of the transition channel 14 is situated on the whole at a closer radial position to the turbine axis A than the exit cross section 24 . Thus, the flow 16 is deflected radially outward from the entry cross section 22 to the exit cross section 24 . Although a height (spacing between inner wall 18 and outer wall 20 ) of the transition channel 14 remains at least essentially constant, without limiting the generality, the cross section of the transition channel 14 recedes from the entry cross section 22 to the exit cross section 24 , since a circumferential length of the exit cross section 24 is greater than a circumferential length of the entry cross section 22 .
[0037] Between the inner wall 18 and the outer wall 20 , which form envelope surfaces of the transition channel 14 , several support ribs 26 extend distributed about the circumference of the transition channel 14 . The support ribs 26 have a comparatively large relative thickness in order to fulfill their support effect and to be able to accommodate supply lines 32 . Furthermore, the support ribs 26 have a winglike profile, which deflects the flow 16 in the circumferential direction.
[0038] In a rear downstream region of the transition channel 14 there are arranged flow splitter blades or vanes 28 between the support ribs 26 . The splitter vanes 28 bring about a flow splitting between the support ribs 26 and help to deflect the flow 16 in the circumferential direction. The splitter vanes 28 are shorter than the support ribs 26 and have a wing profile, which is clearly more slender than the profile of the support ribs.
[0039] Referring still to FIG. 1 , as indicated in the upper part of the figure, three-dimensional parasite secondary flows 30 can form in the axially rear (downstream) region of the transition channel. These secondary flows are induced by the twofold deflecting direction, namely, a deflection radially outward on the one hand and a circumferential deflection to achieve an optimal flow against the first rotor blade series 13 of the low-pressure turbine 12 on the other hand, as well as the complex velocity profile of the flow 16 . These secondary flows 30 can lead to an unfavorable flow onto the following rotor blades 13 of the low-pressure turbine, a greater loading of the structural parts, and an excitation of the rotor blades and contribute to turbine noise. Thanks to the arrangement of the slender splitter vanes 28 between the thicker support ribs 26 , the production of the parasite secondary flows 30 can be substantially reduced.
[0040] Referring now to FIG. 2 , a modification of the layout of FIG. 1 is shown schematically in FIG. 2 . According to the representation in FIG. 2 , not one but two splitter vanes 28 a, 28 b are arranged between two support ribs 26 . The aim is to have the splitter vanes 28 ( 28 a, 28 b ) take over as much of the flow deflection as possible. The number of the long and heavy support ribs 26 is essentially determined by the stability requirements and the number or cross section size of the supply lines ( 32 in FIG. 1 ) to be accommodated in the support ribs 26 .
[0041] In other modifications, the number of splitter vanes 28 between two support ribs 26 can be up to five or even more, if so desired.
[0042] Geometrical sizes of the support ribs 26 and the splitter vanes 28 a, 28 b are indicated in FIG. 2 . An axial design depth of the support ribs 26 is indicated by L ax , a profile chord length by L, and a maximum profile thickness by D max . The corresponding nomenclature for the splitter vanes are rendered by the additional subscript “Splitter”. An axial length or design depth of the transition channel 14 itself can be indicated by L ax, TMTF . The axial design depth L ax, TMTF of the transition channel 14 can coincide with or be defined by the axial length or design depth L ax of the support ribs 26 .
[0043] In summary, features of the present invention that can be combined with each other can be indicated as follows:
a) deflecting support ribs 26 and thin splitter vanes 28 are arranged in tandem fashion in the transition channel 14 ; b) the relative thickness d max, Splitter /L of the splitter vanes 28 nowhere exceeds a limit value
[0000] d max, Splitter /L< 15%; in particular, d max, Splitter /L< 10%; c) the axial design depth of the splitter vanes 28 is
[0000] 25%< L ax, Splitter /L ax, TMTF ; in particular, 30%< L ax, Splitter /L ax, TMTF , and/or
[0000] L ax, Splitter /L ax, TMTF <100%; d) the splitter vanes 28 extend in a region which begins the earliest at 30% L ax, TMTF in the axial direction, i.e., it is set back from the front edges of the support ribs 26 in the flow direction, and ends at no more than 125% of L ax, TMTF, i.e., the splitter vanes 28 can project back behind rear edges of the support ribs 26 in the flow direction.
[0048] It has shown itself to be advantageous for the axial surface ratio F 2 /F 1 to be between 2 and 5 (2≦F 2 /F 1 ≦5) and/or for the deflection angle Δα=α 1 −α 2 to be less than 50°. The entry surface F 1 and the exit surface F 2 here stand perpendicular to the turbine axis A. As can be seen from FIG. 1 , the surfaces F 1 and F 2 are shown at one end and at the other end of the transition channel 14 . The entry flow 16 ′ starting at the turbine axis A is tilted by the entry flow angle α 1 and reflects the entry flow into the transition channel 14 . The exit flow 16 ″ starting at the turbine axis A is tilted by the exit flow angle α 2 and reflects the exit flow from the transition channel 14 . The two flow angles α 1 and α 2 result from the mass-averaged axial and circumferential velocities c Axial and c Umfang in the planes F 1 and F 2 , per α=arctan (c Axial /c Umfang ).
[0049] Moreover, it has proven to be advantageous, in the case of a splitter vane 28 , for the partitions T 1 and T 2 to be different, and for several splitter vanes 28 a, etc., for the partitions T 1 to Tn (for n−1 splitter blades) to be different. The splitter chord lengths L splitter can then also be different.
[0050] In the representation of FIG. 1 , a high-pressure turbine 10 and a low-pressure turbine 12 are only indicated quite schematically. This can involve a high-speed low-pressure turbine when a gear fan is present. Of course, the high-pressure turbine 10 and the low-pressure turbine 12 can be constructed from one or more stages of rotor blade and guide vane series.
[0051] The present invention also finds application in a three-piece turbine layout with a high-pressure turbine, a medium-pressure turbine and a low-pressure turbine. The transition channel of the invention is preferably arranged between the medium-pressure turbine and the low-pressure turbine. However, the transition channel of the invention can also be arranged between the high-pressure turbine and the medium-pressure turbine.
[0052] The high-pressure turbine 10 and the low-pressure turbine 12 are examples of turbine components in the sense of the present invention. The splitter vanes 28 are flow partitioning blades in the sense of the present invention. The arrangement shown in FIG. 1 of a high-pressure turbine, the transition channel 14 , and the low-pressure turbine 12 is part of a turbine unit in the sense of the present invention.
[0053] The present invention is especially applicable to turbine units that are part of a jet engine, especially an aircraft engine.
LIST OF REFERENCE NUMBERS
[0000]
10 high-pressure turbine
12 low-pressure turbine
13 rotor (blade)
14 transition channel
16 ′ entry flow
16 ″ exit flow
18 inner wall
20 outer wall
22 entry cross section
24 exit cross section
26 support ribs
28 flow splitter blades (vanes)
30 secondary flow
32 supply line
d max largest profile thickness of the support ribs
d max, Splitter largest profile thickness of the splitter vanes
A turbine axis
F 1 entry surface at start of the transition channel
F 2 exit surface at end of the transition channel
L profile chord length
L Splitter profile chord length of the splitter vanes
L ax axial design depth of the support ribs
L ax, Splitter axial design depth of the splitter vanes
L ax, TMTF axial design depth of the transition channel
R direction of rotation
T 1 to Tn partitioning (distance (running perpendicular to the turbine axis) between the exit edges of the support ribs and the splitter vanes
The above list of reference symbols is an integral part of the specification. | A transition channel for a turbine unit with at least two components is configured as a flow channel from one component of a first pressure to a component of a second pressure. The transition channel has support ribs, extending between envelope surfaces of the transition channel and having a profile that is configured for the deflecting of a flow from an inlet cross section to an outlet cross section of the transition channel. Flow splitter blades are arranged between the support ribs, having a smaller relative profile thickness than the support ribs and/or a shorter axial design depth or profile chord length than the support ribs. Thanks to the integration of the slim and/or short flow splitter blades (tandem blades), it is possible to largely dissipate parasite secondary flows. | 5 |
FIELD OF THE INVENTION
This invention pertains to a fire-fighting monitor for directing water or water-based foam on a fixed hazard in a hazardous location. More particularly the invention is directed to a stand-by water-powered oscillating monitor which is positionable in a pre-aimed mode in aircraft hangers, fueling areas, docks, mills, tankers, drill rigs, or the like for spray flooding an area to be protected.
BACKGROUND OF THE INVENTION
Oscillating turrets or monitors have been developed and sold in the past to automatically distribute foam, water or foam-water over a specific area as determined by an angle of monitor elevation, arc of oscillation, speed of oscillation, and the foam pattern. Both automatic and manual operation has been provided. Such devices are exemplified by the Model OFC of Feecon Corp., Westboro, Mass., incorporating a clutch mechanism and two four-way valves; the Rockwood Monitor of Rockwood Systems, So. Portland, Me., incorporated a rack and pinion and gear drive; the LO-EX monitor of Walter Kidde Inc., Wake Forest, N.C., including a turbine and gear box drive; and the WOT monitor of Santa Rosa Mnfg. Co., San Jose, Calif., including a four-way valve and chain drive.
A feedback actuated four-way valve controlling a cylinder to actuate a second four-way valve is expensive. Four-way valves are invariably used) are the most trouble-prone part of the system, subject to sticking due to corrosion buildup of deposits of waterborne minerals, or waterborne particulate matter. Cylinder-driven rack and pinion gear arrangements are expensive, subject to alignment problems and require periodic lubrication. Cylinder-driven chain and sprocket arrangements are subject to chain stretch and deflection of the cylinder rod due to eccentric loading of the cylinder by the chain. Turbine and gear box drives are susceptible to sticking of the low torque turbine wheel shaft due to various mechanical problems, including corrosion and waterborne mineral deposition.
Most prior art in fluid-driven devices (going back to early steam engines) used feedback from the output of the engine to actuate a four-way valve which reversed flow to a cylinder, which in turn actuated a second four-way valve which reversed flow to the main power cylinder. Such an arrangement is effective but is very expensive.
SUMMARY OF THE INVENTION
The monitor of this invention is intended as a standby device for use with water-based foam systems. It is typically applied to fight fires where the primary hazard has a definite fixed location, allowing pre-aiming of the monitor. The monitor's oscillating motion is powered by a small flow of agent diverted from the main flow.
The invention is directed to a simplified, less expensive, and smaller arrangement to oscillate a water or water/foam discharge tube. A minimum number of mechanical parts is employed. Use of a vertically mounted piston assembly driven by a minor flow of fire-fighting fluid diverted from the main flow and a concentric cam assembly interconnection between a piston assembly fixed base and the discharge tube and the concentricity of the cylinder, piston rod and vertical inlet pipe, allows for oscillation and reciprocation of the discharge tube in a relatively small floor space. This allows the monitor to be positionable close to any wall of a structure being protected and provides a monitor which is less likely to be damaged by movement of equipment in the area being fire protected. The combination of a hollow piston rod with concentric cams achieves a very compact device with very few parts and an extremely short power train.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a vertical side view of the monitor showing a broken away three-port test valve.
FIG. 2 is a partial cut-away vertical cross-sectional view of the fixed base assembly, the oscillating discharge assembly and the cam interconnection of the assemblies.
FIG. 3 is a partial cut-away top plan view of the base assembly, the discharge assembly and the mechanism producing a toggle action shuttle for control of a four-way valve for reversing the direction of discharge tube oscillation.
FIGS. 4A, 4B and 4C are side views of the torsion springs in successive modes of operation showing the toggle action.
DETAILED DESCRIPTION
As seen in FIG. 1 pressurized flow of agent ("water" as used herein means water or water/foam) from inlet 9 and through bypass 19 is alternately directed by a reversing four-way valve 1 to one end and then the other end of a vertical annular cylinder 2. This forces a piston 3 (FIG. 2) in the cylinder to reciprocate up and down. A reciprocating hollow piston rod 4, sealed by O-rings 60, 61 positioned in the inner wall periphery of housing or rod cap 2b extending above and below the cylinder, is directly connected to a barrel cam 5 having three parallel helical cam tracks 33. Cam rollers 6 engage these tracks, and helical cam tracks 34 in a similar surrounding stationary cam 7. The rolling action of these cam rollers forces the piston 3, piston rod 4, and attached discharge assembly 8 to oscillate as well as reciprocate, with the absolute minimum of mechanical parts. Reciprocation of the discharge assembly due to the cam action is negligible and there is no apparent advantage or detriment by the slight elevational change over the oscillation.
Reversal and angular adjustment of the oscillating motion is accomplished by the action of a pair of set collars 10 (FIG. 1) angularly adjustable by set screw on a curved rod 11 about the monitor's center of rotation 9a, actuating a toggle action shuttle 12, which in turn strokes the spool 16 of a four-way valve 1, reversing the direction of water flow to the drive cylinder 2.
The shuttle 12 is entirely mounted, supported, and guided by four identical torsion springs 13. These springs are wound with their coils axially spaced, allowing them to be loaded in compression as well as torsion. Both free tangential wire ends 13a are bent parallel to the centerline of the coil to allow them to be pivotally mounted to mounts 14. The orientation of these springs with respect to the shuttle and to their fixed mountings 14 is such that:
(1) the two springs at each end of the shuttle are loaded in compression, opposing each other to hold the shuttle in a centered stable lateral position at any and all longitudinal positions throughout the travel of the shuttle, i.e., the axial compressing forces are balanced at all times as shown by the double arrows 13b, and
(2) the vertical force components of the torsional loading of the two springs at each end of the shuttle oppose each other, holding the shuttle at a centered, stable vertical height at any and all longitudinal positions throughout the travel.
These same vertical forces from the springs at one end, being laterally spaced, impart a twisting moment about the longitudinal centerline of the shuttle, which is exactly opposed and balanced by a like moment of opposite direction imparted by the springs at the other end. This holds the shuttle in a stable rotational orientation about the longitudinal centerline of the shuttle throughout its travel.
At the center of the travel of shuttle 12, the centerlines of the pivotal mountings 15 of the springs in the shuttle lie in a vertical plane through the fixed pivotal mountings 14 at the ends of the shuttle which will eliminate any horizontal force component (FIG. 4B). This is an unstable position. The springs are at this point at their maximum torsional load. To either side of this position, the horizontal components of the "torsional" loads on the springs are all additive in a direction away from center.
The above is illustrated for three successive modes of spring action in FIG. 4A, 4B and 4C. In FIG. 4A the lefthand springs of FIG. 3 are shown at the left end of the stroke where the vertical force components DB and BE cancel out at all times and the horizontal components DA and EC push the shuttle to the left with the springs as shown. In FIG. 4B an intermediate center position of the shuttle movement is shown with no horizontal forces present and with the vertical forces AB and BC balanced. In FIG. 4C which illustrates the right end of the stroke as on the left side of FIG. 3, the horizontal forces AD' and CE' push the shuttle to the right while the vertical forces D'B and BE' are balanced. This provides a very strong "toggle" action. The torsion springs are shown in phantom lines at 13c whereat they are expanded outwardly when they all move or pivot during the shuttle cycle.
The shuttle is moved horizontally against the spring force by movement of the set collars 10 adjustably mounted on the circularly curved adjustment rod 11. This adjustment rod is mounted concentric with the center of oscillation 9a of the monitor and oscillates with the adjustment plate 37 and the oscillating "upper half" 8 of the monitor. The set collar as it rotates strikes a tab 50 extending from the shuttle and moves the shuttle to the center position, at which point, the spring force now begins to act in the same direction on the shuttle as it is already moving, resulting in an unloading of the energy stored in the springs and a sudden toggle action, moving the shuttle ahead of the driving set collar.
The shuttle 12 contacts the valve spool 16 somewhat past the shuttle's center of travel, by which point a substantial horizontal force component exists. The shuttle has also already been accelerated to an appreciable velocity, allowing it to impact the end of the spool. The resulting movement of the valve spool is rapid and not dependent on movement of the set collar to carry it through its stroke. This arrangement eliminates any tendency for the monitor to "hang up" at the center of valve travel.
The effective areas upon which water pressure acts are:
(1) upper cylinder annular area 17a between tubular piston rod 4 and cylinder wall 2a (18.87 in. 2 on current configuration);
(2) lower cylinder annular area 18a between tubular rod 4 and cylinder wall 2a (equal to 1)); and
(3) lower end a of tubular rod 4 (9.40 in. 2 , equal to approximately one-half of 1)).
Pressure within the flow passage 19 of the monitor provides the diversion of a minor flow of pressurized (by water main pressure) water or water/foam in inlet 9 and always acts on the end 4a of the rod. This is not a controllable force.
The piston 3 is forced downwardly in the drive cylinder 2 by connecting the upper cylinder 17 by passage 42 to the flow passage 19 and venting the lower cylinder 18 to atmosphere through passage 43. Pressure in the upper cylinder, acting on twice the area of the end of the tubular rod 4, forces the piston 3 down. To reverse the stroke, the upper and lower cylinders are both connected by passages 42, 43, respectively to the flow passage 19 allowing water to flow freely from the upper cylinder to the lower cylinder, as the piston and rod assembly is forced up by pressure in the flow passage acting on the end of the rod. Thus, it will be seen that the upper cylinder 17 is always pressurized, and reversing of piston movement is achieved by simply venting or pressurizing the lower cylinder 18 through passage 43.
Physical accomplishment of the above porting sequence is done with a five-port, four-way directional valve 1 connected in FIG. 1 as follows:
(1) connect vent valve port 20 for the upper cylinder 17 to the pressurized flow passage 19 with line 25.
(2) & (3) both valve "cylinder" ports 21 and 22 are connected to their respective upper and lower cylinders 17 and 18 at cylinder ports 42 and 43 with lines 44 and 45.
(4) vent port 23 for lower cylinder extends to atmosphere.
(5) pressure port 24 is connected with line 28 to a tee 31 in the line 25 between the upper cylinder vent port 20 and the pressurized flow passage 19.
To allow for a "test" connection 26, for use when the flow passage is not pressurized, a three-port directional valve 27 is installed in the "pressure line" 28. The middle port 29 of the three-port valve is connected to the pressure port 24 of the five-port valve. One of the other ports 30 is connected by the mentioned tee 31 to both the upper cylinder vent port 20 and the pressurized flow passage 19. The remaining port 32 of the three-port valve is connected to an external pressure source 26, such as a garden hose water supply. In the "run" position (shown), this three-port valve 27 does not alter the plumbing scheme presented. In the "test" position, it allows the upper cylinder 17 to vent to the empty flow passage 19 resulting in a system where motion results only from pressure in the upper and lower cylinders 17 and 18.
As seen in FIG. 2, the reciprocating motion of the piston-rod assembly 3 and 4 is converted to oscillating motion through use of a pair of helical "barrel" cams 5 and 7. These cams each have three equally spaced helical grooves 33 and 34 of the same hand but with a slightly differing helix angle. In a typical application the helix angle of the first set of tracks on inner cam 5 may be about 29° and the helix angle on outer cam 7 may be about 21°43'. Three crowned cam rollers 6 on the respective barrel cams each engage an inner slot 33 and one outer slot 34. All three rollers are held in place by axles 35 protruding inwardly from a surrounding cam ring 36. On the upward stroke, the rollers 6 contact and roll against the lower surface of the grooves 33 on the inner cam 5 and the upper surface of the grooves 34 on the outer cam 7. A pure rolling action results. On the downward stroke, the action reverses. The rollers 6 contact the upper surface of the inner cam groove 33 and the lower surface Of the outer cam groove 34. Differing cam helix angles are used to insure that at any mid-stroke position, the rollers 6 will be properly "timed" with respect to the relative axial position of the cams; that is they will be at the appropriate vertical position to allow pure rolling for the full stroke in both directions. It is to be noted that if the helix angles were identical, the cams 6 and the attendant cam ring 36 could, at mid-stroke for instance, "fall" down to the bottom of both grooves 33 and 34. Subsequent upward motion of the inner cam 5 would result in sliding of the rollers 6 on the cam surfaces, as the rollers would all be pocketed in the lower ends of the outer cam track 34 and could not roll thereon.
The cam action results in a combination of oscillation and vertical reciprocation (or helical motion) imparted to the discharge assembly 8 ("upper half") including a discharge tube 65 and nozzle attach collar 64. Angular direction feedback from the discharge assembly is required to cause the directional valve 1 to reverse when the upper half 8 reaches a predetermined angular position at either end of the desired stroke. For this purpose, an adjustment plate 37 including the curved adjustment rod 11 and set collars 10 is provided, which can oscillate but not translate vertically. The plate 37 is rotationally loose or mounted to stationary cam 7 and is slidably engaged and driven by a latch 38, movable about pivot 38a and insertable in a notch (not shown) in plate 37, driving plate 37 to move with the discharge assembly 8. A tab 50 on the shuttle is contacted by the collars 10 to initiate shuttle reversal. In FIG. 1 the short double arrows represent the linear shuttle movement while the long double arrows 11a (FIG. 3) represent the rotational movement of plate 37, rod 11 and set collars 10.
A rotatable, sealed, ball-bearing joint 39 connects the upper half 8 and lower half 40, allowing manual operation of the upper half (angularly from side to side). Angular drive of the discharge assembly 8 from the lower half 40 is by means of connection engagement of the latch 38 with a slot 63 between a pair of lugs 41 fixedly connected to the top of the inner cam 5 which is part of the assembly lower half 40. The latch can be disengaged and pivoted or vertically slidable from both the adjustment plate 37 and the drive lugs 41 on the lower assembly half to allow free movement of the upper assembly half 8 (as shown in phantom). The discharge tube assembly 8 can then be freely rotated in bearing 39.
Flow pattern (straight stream versus a "fog" pattern of various cone or fan widths) is a function of the setting of any of the many usable existing auxiliary fire-fighting nozzles which are not a part of this invention. Nozzle elevation (or inclination) is changed by rotating bent tube 65 with respect to elbow 8 at joint 101. A clamping sector plate (not shown) attached to elbow 8 is clamped by a caliper and clamp screw attached to bent tube 65. This is a conventional means used in the industry and is not novel.
The above description of the preferred embodiment of this invention is intended to be illustrative and not limiting Other embodiments of this invention will be obvious to those skilled in the art in view of the above disclosure. | A water-driven monitor is provided as a stand-by pre-aimed fire fighting device installed at a fixed location for fire protection of a structure or equipment, such as aircraft, in a hanger structure. The monitor is oscillated by providing a diversion of a minor flow of the water or water/foam to be discharged from the monitor, to reciprocate an annular piston in an annular cylinder in up and down directions. A pair of concentric barrel cams having helical cam tracks therein and a cam ring with attached cam rollers interconnect a fixed base assembly containing the piston and cylinder and a water or water/foam discharge assembly, such that linear piston motion includes oscillatory motion which is transferred to the discharge assembly. A four-way spool valve controls fluid flow to opposite sides of a piston head and a toggle action shuttle actuates the valve spool to reverse the piston movement and the direction of discharge tube oscillation. A series of four torsion springs, two at each end of the shuttle, provide stored spring energy for the toggle action of the shuttle. | 1 |
FIELD
[0001] The present invention relates, generally, to a power source usable to actuate a subsurface tool.
BACKGROUND
[0002] Subsurface tools, placed downhole within a well, are used for a variety of purposes. Such tools can include packers or plugs, cutters, other similar downhole tools, and setting tools used in conjunction with such devices.
[0003] For example, in a typical downhole operation, a packer can be lowered into a well and positioned at a desired depth, and a setting tool can be positioned above the packer in operative association therewith. An explosive power charge is then provided in conjunction with the setting tool. When it is desired to set the packer, the power charge is initiated, which causes gas to be rapidly produced, forcefully driving a movable portion of the setting tool into a position to actuate the packer to seal a desired area of the well. The gas can also provides sufficient force to shear a shear pin or similar frangible member to separate the setting tool from the packer.
[0004] The force applied to a subsurface tool by a power charge and/or a setting tool must be carefully controlled. The force must be sufficient to set a packer or to similarly actuate a downhole tool; however, excessive force can damage portions of the downhole tool, rendering it ineffective. Additionally, the power charge must be configured to provide force for a sufficient period of time. An explosive force provided for an extremely short duration can fail to actuate a tool, and in many cases a “slow set” is preferred due to favorable characteristics provided when actuating a tool in such a manner. For example, when setting a packer, a “slow set” provides the packer with improved holding capacity.
[0005] Conventional power charges are classified as explosive devices. Most power charges include black powder and/or ammonium perchlorate, and are configured to provide a short, forceful pressure to a subsurface tool to actuate the tool. An explosive force can often create shockwaves within a well bore, which can undesirably move and/or damage various tools and other components disposed within.
[0006] Classification of power charges as explosive devices creates numerous difficulties relating to their transport and use. Shipment of explosive devices on commercial carriers, such as passenger and cargo airplanes, is prohibited. Further, shipment of explosive devices via most trucking companies or similar ground transport is also prohibited. Permissible truck, rail, and ship-based modes of transport are burdened by exacting and costly requirements. Shipments of explosives by rail require buffering areas around an explosive device, resulting in inefficient spacing of cargo with increased cost to the shipper. Shipments by truck require use of vehicles specifically equipped and designated to carry explosive devices, which is a costly process due to the hazards involved. Shipment using ships is subject to regulation by port authorities of various nations, grounded in national security concerns, which greatly increases the time and expense required for the shipment.
[0007] The difficulties inherent in the shipment of explosive devices are complicated by the fact that numerous oil and gas wells requiring use of power charges are located in remote locales, which are subject to various national and local regulations regarding explosive devices, and which often require numerous modes of transportation and numerous carriers to reach.
[0008] Operation of explosive power charges is also restricted, depending on the location in which an operation is to be performed. In many locations, the user of a power charge must be specifically licensed to handle and operate explosive devices. Some nations do not allow transport or use of explosive devices within their borders without obtaining a special permit to requisition a desired explosive device from a designated storage area. In others, various governmental agents or other specialists must be present to ensure safe operation of the device.
[0009] In addition to the regulatory difficulties present when using an explosive power charge, the explosive nature of conventional power charges can also inhibit the effectiveness of such devices.
[0010] In some instances, a packer or similar subsurface tool can become misaligned within a wellbore. Use of an explosive power charge to provide a short, powerful burst of pressure to actuate the tool can cause the tool to set, or otherwise become actuated, in a misaligned orientation, hindering its effectiveness. While conventional power charges are configured to provide a sustained pressure over a period of time, this period of time is often insufficient to allow a misaligned tool to become realigned within a wellbore, while a longer, slower application of pressure (a “slow set”) can cause a tool to become aligned as it is actuated. Additionally, a longer, slower application of pressure to a subsurface tool can improve the quality of the actuation of the tool, as described previously.
[0011] A further complication encountered when using explosive power charges relates to the heat transfer created by the device. Conventional power charges can heat a subsurface tool to temperatures in excess of 2,000 degrees Fahrenheit. These extreme temperatures can cause excessive wear to tool components, leading to the degradation of one or more portions of the tool.
[0012] A need exists for a power source, usable as an alternative to conventional power charges, that does not contain explosive substances, thereby avoiding the difficulties inherent in the transport and use of explosive devices.
[0013] A further need exists for a power source that provides a continuous pressure to a subsurface tool over an extended period of time, enabling alignment of misaligned tools and improving the quality of the actuation of the subsurface tool, while providing an aggregate pressure equal to or exceeding that provided by conventional power charges.
[0014] A need also exists for a power source that provides pressure sufficient to actuate a subsurface tool without increasing the temperature of the tool to an extent that can cause significant damage or degradation.
[0015] The present invention meets these needs.
SUMMARY
[0016] The present invention relates, generally, to a power source, usable to actuate a variety of subsurface tools, such as packers, plugs, cutters, and/or a setting tool operably associated therewith. The present power source incorporates use of non-explosive, reactive components that can provide a pressure sufficient to actuate a subsurface tool. The aggregate pressure provided during the reaction of the components can equal or exceed that provided by a conventional explosive power charge. By omitting use of explosive components, the present power source is not subject to the burdensome restrictions relating to use and transport of explosive devices, while providing a more continuous pressure over a greater period of time than a conventional explosive power charge.
[0017] In an embodiment of the invention, the present power source includes thermite, present in a quantity sufficient to generate a thermite reaction. Thermite is a mixture that includes a powdered or finely divided metal, such as aluminum, magnesium, chromium, nickel, and/or similar metals, combined with a metal oxide, such as cupric oxide, iron oxide, and/or similar metal oxides. The ignition point of thermite can vary, depending on the specific composition of the thermite mixture. For example, the ignition point of a mixture of aluminum and cupric oxide is about 1200 degrees Fahrenheit. Other thermite mixtures can have an ignition point as low as 900 degrees Fahrenheit.
[0018] When ignited, the thermite produces a non-explosive, exothermic reaction. The rate of the thermite reaction occurs on the order of milliseconds, while an explosive reaction has a rate occurring on the order of nanoseconds. While explosive reactions can create detrimental explosive shockwaves within a wellbore, use of a thermite-based power charge avoids such shockwaves.
[0019] The power source also includes a polymer disposed in association with the thermite, the polymer being of a type that produces gas responsive to the thermite reaction. Pressure from the gas produced by the polymer is usable to actuate a subsurface tool, such as by causing movement of a movable portion of a tool from a first position to a second position.
[0020] Usable polymers can include, without limitation, polyethylene, polypropylene, polystyrene, polyester, polyurethane, acetal, nylon, polycarbonate, vinyl, acrylin, acrylonitrile butadiene styrene, polyimide, cylic olefin copolymer, polyphenylene sulfide, polytetrafluroethylene, polyketone, polyetheretherketone, polytherlmide, polyethersulfone, polyamide imide, styrene acrylonitrile, cellulose propionate, diallyl phthalate, melamine formaldehyde, other similar polymers, or combinations thereof.
[0021] In a preferred embodiment of the invention, the polymer can take the shape of a container, disposed exterior to and at least partially enclosing the thermite. Other associations between the polymer and thermite are also usable, such as substantially mixing the polymer with the thermite, or otherwise combining the polymer and thermite such that the polymer produces gas responsive to the thermite reaction. For example, a usable polymer can be included within a thermite mixture as a binding agent. In an embodiment of the invention, the polymer can be present in an amount ranging from 110% the quantity of thermite to 250% the quantity of thermite, and in a preferred embodiment, in an amount approximately equal to 125% the quantity of thermite.
[0022] Use of a power source that includes thermite and a polymer that produces gas when the thermite reaction occurs provides increased pressure when compared to reacting thermite without a polymer. Use of thermite alone can frequently fail to produce sufficient pressure to actuate a subsurface tool.
[0023] The gas produced by the polymer can slow the thermite reaction, while being non-extinguishing of the thermite reaction, which enables the power source to provide a continuous pressure over a period of time. In an embodiment of the invention, the thermite reaction, as affected by the gas, can occur over a period of time in excess of one minute. The aggregate pressure produced by the power source over the time within which the thermite reaction occurs can exceed the pressure provided by a conventional explosive power charge. Additionally, use of a continuous pressure, suitable for a “slow set,” can improve the quality of the actuation of certain subsurface tools, such as packers. Further, when a packer or a similar tool has become misaligned in a borehole, application of a continuous, steadily increasing pressure over a period of time can cause the misaligned tool to straighten as it is actuated. Use of an explosive burst of force provided by a conventional power charge would instead cause a misaligned tool to become actuated in an improper orientation.
[0024] In embodiments of the invention where a “slow set” is not desired, such as when actuating a subsurface tool requiring pressure to be exerted for a period of time less than that of the thermite reaction, one or more accelerants can also be included within the power source. For example, inclusion of magnesium or a similar accelerant, in association with the thermite and/or the polymer can cause a reaction that would have occurred over a period of two to three minutes to occur within ten to twenty seconds.
[0025] In a further embodiment of the invention, the polymer and/or the gas can reduce the heat transfer from the thermite reaction to the subsurface tool, or another adjacent object. While typically, the exothermic thermite reaction can increase the temperature of an adjacent subsurface tool by up to 6,000 degrees Fahrenheit, potentially causing wear and/or degradation of the tool, an embodiment of the present power source can include a quantity and configuration of thermite and polymer that controls the heat transfer of the reaction such that the temperature of an adjacent subsurface tool is increased by only 1000 degrees Fahrenheit or less. During typical use, the present power source can increase the temperature of an adjacent tool by only 225 degrees Fahrenheit or less.
[0026] In operation, a power source, as described above, is provided in operative association with a movable member of a subsurface tool. For example, a packer secured to a setting tool, having a piston or mandrel used to actuate the packer, can be lowered into a wellbore, the power source being placed adjacent to, or otherwise in operative association with, the piston or mandrel. A thermal generator, torch, or similar device usable to begin the thermite reaction can be provided in association with the thermite.
[0027] When the tool has been lowered to a selected depth and it is desirable to actuate the tool, the thermal generator can be used to initiate the thermite reaction, such as by providing current to the thermal generator through electrical contacts with a source of power located at the well surface. The power source can also be actuated using a self-contained thermal generator that includes batteries, a mechanical spring, and/or another source of power usable to cause the thermal generator to initiate the thermite reaction. Initiation of the reaction can be manual, or the reaction can be initiated automatically, responsive to a number of conditions including time, pressure, temperature, motion, and/or other factors or conditions, through use of various timers and/or sensors in communication with the thermal generator.
[0028] As the thermite reacts, the polymer produces gas, the gas from the polymer and/or the thermite reaction applying a pressure to the movable member sufficient to actuate the subsurface tool. The gas from the polymer slows the thermite reaction, thereby enabling, in various embodiments of the invention, provision of a continuous pressure to the movable member over a period of time, and/or prevention of excessive heat transfer from the thermite reaction to the subsurface tool. The thermite reaction can provide a continuous, increasing pressure such that if a packer or similar tool has become misaligned, pressure from the power source will push the tool into alignment prior to actuating the tool.
[0029] The force provided by the power source can be controlled by varying the quantity of thermite and/or the quantity of polymer. In an embodiment of the invention, the force provided by the power source can be used to perform actions subsequent to actuating the subsurface tool. For example, after actuating a setting tool to cause setting of a packer, the force from the power source can shear a shear pin or similar item to cause separation of the setting tool from the packer.
[0030] Embodiments of the present power source thereby provide a non-explosive alternative to conventional explosive power charges, that can provide a continuous pressure over a period of time that equals or exceeds that provided by conventional alternatives, and can reduce heat transfer from the power source to a subsurface tool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] In the detailed description of various embodiments of the present invention presented below, reference is made to the accompanying drawings, in which:
[0032] FIG. 1 depicts an embodiment of a subsurface tool within a wellbore, in operative association with an embodiment of the present power source.
[0033] FIG. 2 depicts a cross-sectional view of an embodiment of the present power source.
[0034] Embodiments of the present invention are described below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0035] Before explaining selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein and that the present invention can be practiced or carried out in various ways.
[0036] Referring now to FIG. 1 , an embodiment of the present power source is shown within a wellbore, in operative association with a subsurface tool.
[0037] Specifically, FIG. 1 depicts a wellbore ( 13 ), drilled within the earth ( 14 ), extending from the surface ( 16 ) to a desired depth. The wellbore has a packer ( 11 ) disposed therein. While FIG. 1 depicts a cased wellbore ( 13 ), it should be noted that embodiments of the power source are usable within any type of hole or opening, including cased or uncased wells, open holes, mines, platforms over subsurface openings, or other similar subsurface locations beneath land or water. Additionally, while FIG. 1 depicts the wellbore ( 13 ) containing a packer ( 11 ), embodiments of the present power source are usable to actuate any type of subsurface tool, including without limitation, packers, plugs, cutters, setting tools, and other devices able to be actuated using pressure.
[0038] The packer ( 11 ) is shown in operative association with a setting tool ( 15 ), usable to actuate the packer ( 11 ). Exemplary setting tools can include such tools as Baker No. 10 and No. 20, from Baker Oil Tools. Another exemplary setting tool is described in U.S. Pat. No. 5,396,951, the entirety of which is incorporated herein by reference. Through actuation by the setting tool ( 15 ), the packer ( 11 ) deploys sealing members ( 51 ) against the inner circumference of the wellbore ( 13 ).
[0039] A firing head ( 17 ) is shown coupled to the setting tool ( 15 ), the firing head ( 17 ) containing an embodiment of the present power source (not visible in FIG. 1 ). The power source within the firing head ( 17 ) is operatively coupled with a movable member (not shown) of the setting tool ( 15 ), such that gas produced by the power source applies to the setting tool ( 15 ) a pressure sufficient to cause actuation of the setting tool ( 15 ). An electrical conduit ( 45 ) is shown connecting the firing head ( 17 ) to a source of power (not shown) disposed at the surface ( 16 ), for ignition of the power source. Other sources of power, such as batteries, a downhole source of power, a mechanical source of power, or similar sources of powers, are also usable, such that a electrical connection between the firing head ( 17 ) and the surface ( 16 ) is not required.
[0040] Referring now to FIG. 2 , an embodiment of the present power source ( 21 ) is shown, disposed within the firing head ( 17 ). The power source ( 21 ) is shown including a quantity of thermite ( 23 ), partially encased by a polymer ( 25 ), the polymer ( 25 ) defining a bottom wall ( 31 ) and a side wall ( 33 ). In one or more embodiments of the invention, the bottom wall ( 31 ) and/or the side wall ( 33 ) can be omitted, and the thermite ( 23 ) can be pressed against a stop or wall within the firing head ( 17 ) or against the setting tool ( 15 ).
[0041] The top of the thermite ( 23 ) is shown enclosed by a cap ( 41 ). The firing head ( 17 ) can also include an outer cap ( 42 ), which is shown enclosing the power source ( 21 ) contained within, enabling the entirety of the pressure produced by the power source ( 21 ) to actuate a piston ( 43 ) within the setting tool ( 15 ) by directing the pressure produced by the power source ( 21 ) in a downhole direction. A thermal generator ( 27 ) is shown disposed in contact with the thermite ( 23 ) for initiating the thermite reaction. The electrical conduit (depicted in FIG. 1 ) is usable to activate the thermal generator ( 27 ). A typical thermal generator can produce heat sufficient to ignite the thermite ( 23 ) responsive to electrical current. An exemplary thermal generator is shown and described in U.S. Pat. No. 6,925,937, the entirety of which is incorporated herein by reference. Usable thermal generators can include any source of heat for initiating the thermite reaction, including direct contact between heating elements and the thermite or use of a heat source in communication with a separate controlled quantity of thermite used to initiate the thermite reaction within the power source ( 21 ).
[0042] While the polymer ( 25 ) is shown having the structural form of a container or sleeve for containing or otherwise partially or wholly enclosing the thermite ( 23 ), the polymer ( 25 ) can be combined with the thermite ( 23 ) in any manner that permits the polymer ( 25 ) to produce gas responsive to the thermite reaction.
[0043] Thermite includes as a mixture of powdered or finely divided metals and metal oxides that reacts exothermically when ignited. The resulting thermite reaction is classified as non-explosive, the reaction occurring over a period of milliseconds, rather than nanoseconds. Specifically, thermite can include powdered aluminum, magnesium, chromium, nickel, or other similar metals, mixed with cupric oxide, iron oxide, or other similar metal oxides. In a preferred embodiment of the invention, the thermite ( 23 ) includes a mixture of aluminum and cupric oxide.
[0044] The polymer ( 25 ) can include any polymer or copolymer, including but not limited to polyethylene, polypropylene, polystyrene, polyester, polyurethane, acetal, nylon, polycarbonate, vinyl, acrylin, acrylonitrile butadiene styrene, polyimide, cylic olefin copolymer, polyphenylene sulfide, polytetrafluroethylene, polyketone, polyetheretherketone, polytherlmide, polyethersulfone, polyamide imide, styrene acrylonitrile, cellulose propionate, diallyl phthalate, melamine formaldehyde, or combinations thereof.
[0045] The quantity of polymer ( 25 ) within the power source ( 21 ) in relation to the quantity of thermite ( 23 ) can be varied depending on the subsurface tool to be set. For example, when setting a packer, approximately 25% more polymer than thermite by weight can be used. In other embodiments of the invention, the quantity of polymer can range from 110% the quantity of thermite to 250% the quantity of thermite by weight. It should be understood, however, that any quantity of polymer in relation to the quantity of thermite can be used, depending on the desired characteristics of the power source and the pressure to be produced.
[0046] In an embodiment of the invention, the power source ( 21 ) can also include an accelerant (not shown), such as magnesium, mixed or otherwise associated with the thermite ( 23 ) and/or the polymer ( 25 ).
[0047] In operation, electrical current is provided to the thermal generator ( 27 ), via the electrical conduit (depicted in FIG. 1 ) or using another similar source of power. Once the thermal generator ( 27 ) reaches the ignition temperature of the thermite ( 23 ), the thermite ( 23 ) begins to react. Heat from the thermite reaction heats the polymer ( 25 ), which causes the polymer to produce gas, which is at least partially consumed by the thermite reaction, thereby slowing the reaction. Absent the polymer ( 25 ), the thermite would react rapidly, in a manner of seconds or less. Through use of the polymer ( 25 ) to attenuate the reaction, the thermite reaction can occur over several minutes, generally from one to three minutes. The gas produced by the polymer ( 25 ) further increases the overall gas pressure produced by the thermite reaction.
[0048] The gas from the polymer ( 25 ) and/or the thermite reaction, confined by the outer cap ( 42 ), breaches the bottom wall ( 31 ) to apply pressure to the piston ( 43 ), thereby actuating the subsurface tool ( 15 ). The thermite reaction is not temperature sensitive, thus, the power source ( 21 ) is unaffected by the temperature of the downhole environment, enabling a reliable and controllable pressure to be provided by varying the quantity of thermite ( 23 ) and polymer ( 25 ) within the power source ( 21 ). Through provision of a “slow set” to a packer or similar tool, such as a continuous pressure for a period of one minute or longer, elastomeric sealing elements obtain greater holding capacity than sealing elements that are set more rapidly.
[0049] Subsequent to the thermite reaction, the thermite ( 23 ) and polymer ( 25 ) can be substantially consumed, such that only ash byproducts remain. The quantity of thermite ( 23 ) and/or polymer ( 25 ) can be configured to vary the reaction rate and the pressure provided by the reaction. For example, the length of the firing head ( 17 ) can be extended to accommodate a larger quantity of thermite ( 23 ) and/or polymer ( 25 ) when a longer reaction is desired. Similarly, a longitudinal hole or similar gap can be provided within the thermite ( 23 ) to shorten the reaction time.
[0050] While various embodiments of the present invention have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein. | A power source for actuating a subsurface tool is described herein, the power source comprising thermite in a quantity sufficient to generate a thermite reaction, and a polymer disposed in association with the thermite. The polymer produces a gas when the thermite reaction occurs, the gas slowing the thermite reaction. The slowed thermite reaction enables a continuous pressure to be provided to the subsurface tool over a period of time, providing superior actuation over a conventional explosive power charge, through a non-explosive reaction. | 4 |
This invention relates to a method of securing a load bearing structure to the bed of a sea, river or estuary, and is particularly, although not exclusively, concerned with the installation of anchorages for structures such as power generating equipment using water current energy. The present invention also relates to a load bearing structure in combination with drilling equipment for use in securing the load bearing structure.
BACKGROUND
It is becoming clear that many sites for water current energy systems comprise hard or rocky beds. Existing methods of drilling underwater rock sockets typically require a fixed drilling platform such as a jack-up vessel. This becomes expensive in water depths of more than approximately 30 m because it can no longer be carried out using relatively cheap and available near-shore construction jack-up vessels, but instead requires expensive specialist offshore vessels such as mobile drilling units (MDUs) or dynamically positioned (DP) drilling ships. It is possible that dedicated installation jack-ups could be developed for ocean energy installations; however, these would need to be capable of standing in water up to 70 m deep in order to capture a significant proportion of the UK tidal energy resource. This is a significant extension of current operating envelopes, and there are currently no indications that this could be achieved cost-effectively.
It is known to drill into rock using rotary drilling or percussive drilling.
The problems associated with using a conventional large diameter rotary drill are firstly that there is little if any of such equipment capable of operation underwater, and secondly that the equipment is large and relatively complex, and requires to be mounted on a structure which can react the large torques generated. The drill string is heavy and the vessel required to deploy it is correspondingly large.
Fluid-operated percussive drilling equipment is existing technology and has been used for onshore and offshore drilling. In the offshore environment, however, it has only previously been deployed using surface-breaking rigid drill stringers operated from stable drilling stringers.
There is therefore needed a cost-effective means of securing anchorages, moorings or foundations to the bed of a body of water.
SUMMARY OF INVENTION
In a first aspect of the present invention, there is provided a method of securing a load bearing structure to the bed of a sea, river or estuary, the method comprising the steps of: placing the load bearing structure on the bed; forming a pile-receiving hole in the bed by means of drilling equipment which is connected to a surface vessel by flexible lines only so that the weight of the drilling equipment is supported by the bed, the drilling equipment being guided by the load bearing structure, and the load bearing structure resisting any non-vertical loads imparted to the drilling equipment; and withdrawing the drilling equipment and installing an attachment pile within the formed hole.
In a second aspect of the present invention, there is provided, in combination, a load bearing structure for installation on the bed of a sea, river or estuary, and drilling equipment for use in the installation of the load bearing structure, the drilling equipment being adapted for deployment from a surface vessel by flexible lines only, the load bearing structure being provided with guide means for guiding the drilling equipment during a drilling operation on the bed, the guide means and the drilling equipment cooperating with each other to permit vertical displacement of the drilling equipment relative to the guide means but to resist non-vertical loads imparted to the drilling equipment.
A method in accordance with the present invention provides a cost-effective means of carrying out drilling in cases where beds are hard or rocky. Such a method can be employed to install a wide range of piles, from shallow-embedment “shear keys” to deeper pile embedments capable of carrying uplift forces. The technique is generic and therefore suitable for any type of seabed anchorage or mooring; however, the main applications discussed below are foundations for ocean and water current energy systems, for example wave, tidal stream and offshore wind energy conversion systems.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the following drawings, in which:
FIGS. 1 a and 1 b show a method of deployment of a drilling system and attachment pile to secure a support structure to the seabed;
FIGS. 2 a to 2 c show the support structure at different stages of the securing process; and
FIGS. 3 a to 3 c correspond to FIGS. 2 a to 2 c but show an alternative securing process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a , a support structure is positioned on the bed of a body of water. The support structure comprises a central column 30 stabilized by support feet in the form of hollow members 1 . In an alternative embodiment there may be only one hollow member, which may be positioned substantially centrally within the support structure.
A workboat 8 lowers a drill string down into one of the hollow members 1 . The drill string is an axial assembly comprising all the equipment necessary to operate the drill, such that all equipment may be recovered by the workboat 8 in a single lift after drilling. This may include, but is not restricted to, weights, drive motors for slow indexing of the drill bit, power swivel to receive the power for the drill from an umbilical whilst allowing the drill to index around, and guidance channels to control the exhaust fluid velocity to ensure the removal of drillings.
In the embodiment shown in FIG. 1 a , the drill string is a percussive drilling system. Thus the drill string is made up of a percussion drill 2 , a weight 3 , an air swivel 4 and a motor 5 to rotate the percussion drilling system.
Percussive drilling techniques make use of the inertia of an axially oscillating heavy piston striking the drill bit to provide the crushing forces necessary to chip off and remove rock fragments. The drill strings required are much lighter than rotary drilling equipment of equivalent power, they do not require significant torque reaction, and are designed for operation underwater.
As it is lowered, the full weight of the drill string is supported by a cable 32 from a deck-mounted crane 7 on the workboat 8 . Pneumatic, hydraulic, electric or any other connections necessary for the drill string to operate correctly are made between the drill string and the workboat 8 by flexible umbilicals 6 . The umbilicals 6 are fitted with helical vortex-induced vibration suppressors and/or joined together at intervals in a manner so as to provide damping against loads induced by currents.
As will be described in more detail below, the drill string is lowered through the guide provided by the hollow member 1 and comes to rest on the bed of the body of water. Thus, during drilling, the load of the drill string is supported by the bed of the body of water.
Once a hole of the required depth has been drilled as described above, the drill string is retrieved from the bed. As shown in FIG. 1 b , an attachment pile 9 is lowered from the workboat 8 into the hole through the hollow member 1 .
Referring to FIG. 2 a , the hollow member 1 has been cross-sectioned to show the drill string in position on the bed, ready to drill.
The percussion drill 2 rests on the bed such that the weight of the drill string is taken off the crane hook 10 . Additional weight 3 has been attached on top of the percussion drill 2 to enhance the percussive effect of the drill. The drill string is turned by the motor 5 , and air to power the percussion drill 2 is provided by the air swivel 4 from one of the umbilicals 6 . Another of the umbilicals 6 may comprise an electric cable to supply power to the motor 5 .
The drill string has torque arms 12 that engage with guide vanes 11 on the inside of the hollow member 1 . The guide vanes 11 support the reaction torque of the motor 5 , so that the drill operates correctly.
In the condition shown in FIG. 2 b , the drill 2 has completed a hole in the seabed. As the depth of the hole increases, the motor torque arms 12 slide down the guide vanes 11 . The drillings are ejected out of the top of the hollow member 1 to the environment. Once the required depth of hole has been drilled, the drill string can be lifted out by the deck-mounted crane on the surface (see FIG. 1 a ).
Referring to FIG. 2 c , the drill string has been removed and the attachment pile 9 has been lowered into the hole from the surface (see also FIG. 1 b ). The attachment pile 9 is a steel cylinder fitted with grout tubes 14 which are attached to grout lines running to the surface. Grout is pumped down these tubes to fill the annulus between the attachment pile 9 and the hollow member 1 on the one hand, and the annulus between the attachment pile 9 and the inside of the hole on the other hand. Grout is also supplied to the inside 13 of the attachment pile. The grout lines are then detached and retrieved to the surface vessel 8 .
In an alternative embodiment, the attachment pile 9 is attached to the support structure by mechanical means, for example bolts, welding or expanding mandrels.
FIGS. 3 a to 3 c show an alternative process, although the same reference numbers have been used for similar components as in FIGS. 2 a to 2 c . Referring to FIG. 3 a , the hollow member 1 has been cross-sectioned to show a different drill string arrangement resting on the seabed, ready to drill. The percussion drill 2 rests on the seabed, with the weight taken off the crane hook 10 . In this embodiment, the attachment pile 9 forms part of the drill string, and fits inside the hollow member 1 , aligning the drill string vertically. The attachment pile 9 is attached to the percussion drill 2 , such that as the drilling process takes place, the attachment pile 9 is pulled into the hole at the same time as the hole is created.
The attachment pile 9 is attached to the percussion drill 2 at its base using a remotely detachable fitting 17 . This fitting 17 could be a hydraulically or pneumatically actuated pin which engages with a female fitting fixed to the inside wall of the attachment pile 9 . Those skilled in the art will be able to think of alternative fittings that are to be considered within the scope of the present invention.
The percussion drill 2 incorporates an under-reamer 16 , which can be deployed for drilling, but is radially retractable in order to allow the drill string to be removed. Thus, during drilling the under-reamer 16 extends the diameter of the drilled hole, so that the attachment pile 9 can fit easily inside it. After drilling, the under-reamer 16 retracts radially so the drill string can be removed from inside and underneath the edges of the attachment pile 9 .
As in the process described with reference to FIGS. 2 a to 2 c , additional weight 3 is attached to the percussion drill 2 . Guides 20 keep the drill string aligned vertically within the attachment pile 9 . As in the first embodiment, the drill string is turned by the motor 5 , and air to power the percussion drill 2 is provided via the air swivel 4 from an umbilical 6 . Again, a further umbilical 6 can be used to power the motor 5 as necessary.
In order to prevent the hollow member 1 from being excessively tall, a releasable extension 18 is used to extend the height of the hollow member 1 . The extension 18 is attached to the top of the hollow member 1 using a tapered fitting 21 . The torque arms 12 engage with guide vanes 11 on the inside of the extension 18 . The guide vanes 11 are fitted with stops 15 at the top of the extension 18 , so that when the drill string is removed from the hollow member 1 , the torque arms 12 abut against the stops 15 and the extension 18 is retrieved along with the drill string. This embodiment is especially useful when a deep embedment hole is required.
Referring to FIG. 3 b , the drill string has made a hole in the seabed by turning the motor 5 and powering the percussion drill 2 . As the drill string makes the hole the motor torque arms 12 slide down the guide vanes 11 on the inner wall of the extension 18 . The drillings are ejected out of the top of the attachment pile 9 , from where they are ejected to the environment either out of the top of the hollow member 1 or through holes 19 made in the wall of the extension 18 .
Once the required depth of hole has been drilled, the under-reamer 16 is retracted and the remotely detachable fitting 17 is released. The drill string can then be lifted out vertically by a deck-mounted crane on the surface. As described above, the extension 18 is also lifted out by virtue of the stops 15 .
Referring to FIG. 3 c , the drill string has been removed, leaving the attachment pile 9 in place. Grout is pumped into the annulus between the attachment pile 9 and the inside of the hollow member 1 and the inside of the hole, also flowing inside the attachment pile itself. This could be achieved using a similar grout-tube arrangement as shown in FIG. 2 c . Alternatively grout could be pumped through grout tubes that run inside the tubular framework of the support structure through the wall of the hollow member (not shown). One skilled in the art may be able to think of further alternatives without departing from the scope of the invention.
There is therefore described a method and equipment for installing underwater anchorages to the bed of a body of water. The present invention has several advantages:
1. it can be used to install piles of sufficient embedment to carry significant uplift forces as well as shear and other loads, and is therefore suitable for all types of anchorages and moorings, including foundations for many types of ocean and water current energy converters; 2. it can be deployed in any water depth; 3. the drill string is deployed using flexible umbilicals instead of a rigid drill string, which eliminates the need for an expensive drill ship, DP vessel, or heave-compensated crane. Installation can be achieved using smaller, cheaper, more readily available non-specialist vessels, which makes the process considerably quicker and more flexible; 4. the drill string is relatively light (typically only 10 tonnes or so for holes up to 1.2 m diameter), which makes for ease of handling and rapid deployment. The deployment vessel requires a crane with sufficient capacity only to lower the drill string to the bed; 5. it makes use of the foundation structure as a drilling template, removing the need for separate templates or alignment devices. This is achievable because of the low reaction loads and minimal guidance requirements of the drill; 6. owing to the deployment of the drill string inside the template (for example inside a hollow member or an attachment pile) it is well protected from water currents and, unlike a conventional surface-breaking stringer, is not exposed to drag loads and vortex-induced vibration (VIV). This technique is therefore particularly advantageous for installing foundations for water current energy systems and wave energy systems; 7. if necessary, the drilling operation can quickly be aborted at any stage in the process simply by raising the drill string to the surface. Drilling can subsequently be restarted by lowering the drill string back down into the hole and using the template guides to pick up on the previous drilling. | A method of securing a load bearing structure to the bed of a sea, river or estuary. The method comprises placing the load bearing structure on the bed; forming a pile-receiving hole in the bed by means of drilling equipment which is connected to a surface vessel by flexible lines only so that the weight of the drilling equipment is supported by the bed, the drilling equipment being guided by the load bearing structure, and the load bearing structure resisting any non-vertical loads imparted to the drilling equipment; and withdrawing the drilling equipment and installing an attachment pile within the formed hole. | 4 |
This Application claims benefit to Provisional No. 60/112,548 filed Dec. 10, 1998 which claims benefit to Provisional No. 60/133,798 filed May 11, 1999.
The present invention relates to a method of removing oil from oil contaminated material. This invention also relates to a method of removing chloride from the oil contaminated material after the oil has been removed. The present invention also relates to an apparatus designed for this purpose.
BACKGROUND OF THE INVENTION
The present invention is a treatment method best described as a chemically induced hydrocarbon extraction process for the removal of oil from oil contaminated material. For example, oil contaminated well bore cuttings are created when oil based drilling fluid (mud) is utilized in the drilling process during oil exploration. The drilling fluid (drilling mud) is injected into the bore hole during the drilling process for the purposes of lubrication, cooling, controlling sub-surface pressure to prevent blowouts, stabilization and to assist in the removal of cuttings from the hole. The combination of drilling fluid (mud) and soil is brought to the surface where the oil based drilling mud is separated from the well bore cuttings and the oil based mud reused. During the separation process a considerable amount of fines are introduced into the drilling mud portion. This drilling mud can be reused until the concentration of solids exceeds in most cases 15 to 16 percent, at which time the mud has to be reworked. The resulting well bore cuttings containing unwanted oil are considered hazardous waste and present a large environmental problem during disposal as well as the safety hazards associated with handling combustible material.
Various technologies have been offered in an attempt to safely, efficiently and cost effectively remove the oil from well bore cuttings such as: incineration, thermal desorption (indirect fired), dirt burning (direct fired), screening and centrifugation, deep well injection, water based solvent washing solutions, and land farming. Incineration, thermal desorption, dirt burning are expensive as well as dangerous due to the real potential for explosion. Screening and centrifugation has proved to be ineffective as these methods are only capable of reducing oil concentrations to 10 to 15% by weight and the regulatory agencies, for example in the North Atlantic, are requiring less than 1% by weight remaining in the well bore cuttings before. discharge overboard in offshore oil drilling. Deep well injection is expensive and a questionable environmental solution. Water based solvent washing solutions appear to be effective in treating well bore cuttings where water based drilling fluids are used but not when oil based drilling fluids are used. This process is expensive and creates a need for water treatment. Land farming is expensive and takes a number of years to complete the process.
The trend in the industry is to lower discharge limits for hydrocarbon contaminated well bore cuttings. This has already been realized in the North Sea and in the Gulf Of Mexico. In the North Atlantic for example, the regulations are currently at the 15% hydrocarbon discharge criteria. The level will be reduced to 1% by weight in the near future.
This invention also provides a method for the reduction of chlorides in the well bore cuttings that are generated during land based drilling or exploration which commonly reach concentration in excess of 18000 ppm. The two most important criteria that have to be met when looking at landfill well bore cuttings in, for example, the province of Alberta, are reducing oil concentrations to less than 2.5% by weight and chlorides to less than 2500 ppm. When the oil based drilling fluid is constructed, calcium chloride or potassium chloride is commonly used for structural stabilization of the well bore hole.
There is thus a need in the industry to reduce the level of oil in oil contaminated material in the oil field. There is also a need to reduce the level of chlorides in land based drilling fields.
SUMMARY OF THE INVENTION
Thus, according to the present invention there is provided a method of removing oil from oil contaminated solids-containing material. This invention also relates to a method of removing chloride from the oil-depleted material, the oil contaminated solids-containing material after the oil has been removed. This invention also relates to an apparatus designed to accomplish the methods of the present invention.
In one embodiment of the present invention there is provided a process to extract oil from oil contaminated well bore cuttings so as to produce clean cuttings.
This invention further provides a quality of oil that can be reused in the construction of oil based drilling fluid or recycled for other purposes, such as fuel.
In a further embodiment of the present invention there is also provided a method to reduce chloride concentration to a level for safe land fill disposal during land based drilling operations. This can only be accomplished after the oil has been removed from the soil particles, which will then expose the more difficult to remove chlorides, that are attached to the soil particles that make up the well bore cuttings.
The removal of the contaminating oil in the well bore cuttings is accomplished by contacting the cuttings with a combination of surfactants in an oil carrier.
Thus according to one embodiment of the present invention there is provided a method of extracting oil from oil contaminated solids-containing material comprising:
mixing the oil contaminated solids-containing material with a combination of one or more surfactants in an oil carrier to provide a solids-containing treated material; and
subjecting the solids-containing treated material to one or more separating steps to extract oil therefrom and to provide an oil-depleted solids-containing material.
In a further embodiment of the present invention the method further comprises a step of removing the chloride from land based oil contaminated material.
In this embodiment there is provided a method of extracting oil and chloride from oil contaminated material comprising:
mixing the oil contaminated solids-containing material with a combination of one or more surfactants in an oil carrier to provide a solids-containing treated material;
subjecting the solids-containing treated material to one or more separating steps to extract oil therefrom and to provide an oil-depleted solids-containing material; and
treating the oil-depleted solid-containing material to reduce the concentration of chloride ions in the oil-depleted solid-containing material.
This invention also comprises an apparatus for achieving the methods of the present invention. In the embodiment of the present invention, which comprises the extraction of oil from oil contaminated material the apparatus comprises:
a means for mixing the oil contaminated solids-containing material with a surfactant-containing treating liquid to provide a solids-containing treated material; and
means for subjecting the treated materials to one or more separating steps to extract oil therefrom and provide an oil-depleted solid-containing material.
In the embodiment of the present invention which comprises the further step of separating the chloride from the treated material, the apparatus of the present invention further comprises:
a further mixing means;
a means to transport the oil-depleted material into the further mixing means;
a chemical input means for introducing a composition comprising one or more surfactants in a water carrier into the further mixing means; and
a separation means for separating the water carrier, which now includes chloride ions, from the further treated material.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the material flow diagram for hydrocarbon treatment.
FIG. 2 shows the material flow diagram for chloride treatment.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates to a method of removing oil from oil contaminated material. This invention also relates to a method of removing chloride from the oil contaminated material after the oil has been removed. The present invention also relates to an apparatus designed for this purpose.
According the present invention the apparatus and process can be used to remove contaminated oil from a variety of contaminated materials. For example oil can be removed from well bore cuttings, processed sand, oil tank bottoms, slop oils, and fixated or stabilized drilling muds to name only a few examples. Oil can also be removed from pits that have served as a holding reservoir for oil contaminated materials. The oil contaminated material can also include under flow fines, which are fines removed from a combination of well bore cuttings and drilling mud that is brought up to the surface. The concentration of oil in the solid material to be treated can range from about 5% to about 60%; however, concentrations of from about 12% to about 30% are more typical in the art.
According to the present invention the oil contaminated material is treated with a composition comprising one or more surfactants in an oil carrier.
In one embodiment of the present invention the surfactant or combination of surfactants have a hydrophilic—lipophilic balance (HLB) of less than 10. The HLB is a ratio of the water/oil affinities of an emulsifier. A surfactant with a HLB of 1 to 10 is more soluble in oil than in water. A surfactant with a HLB of 10 to 20 is more soluble in water than in oil. Thus, as the present invention avoids the presence of water, although of course there will always be some water present in the system, it is preferred that the surfactants of the present invention have an HLB of less than 10. In one embodiment of the present invention the surfactants have a HLB value of less than 8. These surfactants are also sometimes know as lipophilic surfactants.
In one embodiment of the present invention the surfactants are a combination of saturated fatty acid alcohols.
In a further embodiment of the present invention the surfactants are a combination of ethoxylated lauryl alcohol, lauryl alcohol and myristic alcohol.
In one embodiment of the present invention the surfactants are a combination of the following:
myristic alcohol 1 to 5% (w/w);
lauryl alcohol 1 to 5% (w/w); and
ethoxylated lauryl alcohol 10 to 30% (w/w).
This combination of surfactants is sold under the name Rhodasurf LA-3 by Rhone Poulenc Canada Inc. Suitable surfactants are also available from other manufactures.
The surfactant combination is dissolved or dispersed in a sufficient quantity of an appropriate oil as a carrier. In one embodiment of the present invention the surfactant combination is dissolved or dispersed in the oil carrier at a concentration range of about 0.25% to about 20% by volume. In another embodiment of the present invention the concentration of surfactant in the oil carrier is from about 0.5% to about 4%.
The oil carrier should be selected from a hydrocarbon within the range of C 12 to C 22, which could include the following:
Synthetic oils—examples are IPAR 3 and LTMO (low tox mineral oil)
Non-synthetic oils—examples are mineral oil, kerosene, diesel and cutter stock.
In one embodiment the carrier oil is identical to the oil present in the well bore cuttings to maintain consistency for reuse as a drilling mud.
The volume of surfactant containing oil required to treat one ton of well bore cuttings would range from about 50 ml to about 1000 ml. In a further embodiment of the present invention the volume of surfactant containing oil required to treat one ton of well bore cuttings would range from about 100 ml to about 200 ml. In some embodiments of the present invention the solid material is pre treated with surfactant in the oil carrier. In this pre treatment step about one ton of material is treated with from about 6 to about 10 liters of chemical composition, containing about 1% surfactant.
The surfactant containing oil would contact the oil contaminated material at a temperature within the range of 10° C. to 70° C.
The contact time should range from 0.5 seconds to one hour or greater.
Following the mixing of the surfactant containing oil with the oil contaminated material, the oil is separated from the treated material.
According to the present invention the separation step is accomplished by mechanical means, such as vacuum filtration, air stripping, centrifugation, and cyclones, or a combination of any of these means.
In one embodiment the invention the material to be treated is first heated to from about 40° C. to about 60° C. Any known method can be used to heat the oil contaminated solids-containing material. The surfactants in the oil carrier can be added during this heating step or following said heating step. In one embodiment the surfactant and oil carrier can be heated before it is mixed with the oil contaminated solids-containing material to provide the required heat. The oil is then separated from the material by vacuum filtration. In this embodiment the material can be placed on a horizontal vacuum belt. In this embodiment of the present invention the vacuum belt can be comprised of at least two sections, a vacuum section and a drying section. The vacuum section, which would be shorter than the drying section, would remove a substantial portion of the oil from the contaminated material at a vacuum of about 5 to about 9 inches of mercury. The remaining material would be exposed to dry heat from above at temperatures ranging from about 100° C. to about 160° C. Additional oil would be removed by vacuum from below at from about 5 to about 9 inches of mercury. It may also be necessary in this embodiment to break up the cake following the first vacuum treatment before exposing the material to the drying step.
In some embodiments it may not be necessary to include the first vacuum step. In this embodiment 4400 cubic feet per minute of warmed air is directed toward the solids-containing treated material. In this embodiment, as depicted in FIG. 1, there are six vacuum exhausters each pulling a volume of air of about 850 cfm, for a total of 5100 cfm, drawing a vacuum that will not exceed 9 inches of mercury.
The amount of oil removed is directly proportional to the time of exposure to the combination of hot air and vacuum. With the addition of the hot air during the extraction process, we were able to achieve less than 0.5% oil remaining in the oil-depleted solids-containing material. In this embodiment of the present invention some form of air filtration, such as a carbon filter, may be required to capture air born oil particles in the vacuum exhaust.
In a further embodiment of the present invention the oil is separated from the solids-containing treated material using centrifugation. In this embodiment the invention the material to be treated can first be heated to from about 40° C. to about 60° C. The surfactants in the oil carrier can be added during this heating step or following said heating step. Although if centrifugation is used as the separation technique, heating may not be necessary. The oil is then separated from the material by centrifugation. In a continuous flow centrifuge about 3 to about 9 tons of material can be treated per hour, at centrifugation speed ranging form about 3200 rpm to about 6000 rpm, depending on the type of centrifuge used. Any suitable centrifuge known in the art can be used to separate the solids-containing treated material from the oil. It is preferred that the centrifuge is a continuous centrifuge, for example a decanter centrifuge. For small samples a Sharples P660 centrifuge can be used and the centrifugation speed can be up to about 6000 rpm. For large samples, as defined in Example 4, an Alfa Laval DMNZ 418 FTVB decanter centrifuge can be used. In this example, the centrifuge is run at about 3200 rpm.
In yet a further embodiment of the present invention the oil is separated from the solids-containing treated material using first a centrifugation step, as described above, followed by a vacuum drying step, also as previously described. This initial centrifugation treatment should remove all but from about 2% to about 3% of the oil from the material. Additional oil can be removed using a vacuum drying step. The oil remaining after this further vacuum drying step can be reduced to at least 1%, or even as low as 0.5%.
The apparatus used to practice the present invention is shown in FIGS. 1 and 2. FIG. 1 shows the apparatus used for the removal of oil from the oil contaminated material. FIG. 2 shows the apparatus used for the removal of chloride from the material after the oil has been removed, the oil-depleted solids-containing material.
As depicted in FIG. 1 the untreated solids ( 10 ) are pumped using a suitable pump means ( 12 ) into a horizontal decanter centrifuge ( 14 ). Prior to entering the centrifuge the untreated solids are mixed with the surfactant and oil carrier by a chemical/carrier oil injection means ( 16 ), from a chemical/carrier oil reservoir ( 17 ). According to the present invention a single or double piston concrete/grout pump can be used as the suitable pump means. In some embodiments of the present invention additional chemical material can be added as a pretreatment or conditioning step, while the solid material to be treated is being pumped. For this purpose a Master Builders Technologies POWERCRETER (TM) PRO pump has been found to be particularly useful as it has mixing capabilities. Once the surfactant has been added to the solid material there is a drop in viscosity of the solid material, which improves its pumping ability.
From the centrifuge the liquid oil is collected for re-use from a valve means ( 18 ) in the centrifuge into a suitable container ( 19 ). The solid material is discharged from the centrifuge onto a horizontal belt filter ( 20 ) of a vacuum extraction means, referred to generally by reference number 21 . The belt filter according to this embodiment of the present invention has a surface area of approximately 23 square feet.
The vacuum extracter comprises an air inlet port ( 22 ) through a blower ( 24 ) that directs the air over heating elements ( 26 ), preferable electric heating elements located in a hood ( 28 ). The volume of the air entering the hood is about 4400 cfm (cubic feet per minute). The heating elements are located directly above the belt filter. Preferable the heating elements are about 10 to about 16 inches above the belt filter. The air is heated to from about 100° C. to about 160° C. as it comes over the heaters. In one embodiment of the present invention the air is heated to about 145° C. The vacuum tray ( 30 ), which initially collects the oil is located beneath and in direct communication with the vacuum belt.
The treated solids ( 31 ) are collected at the end of the vacuum belt and can then be released into the environment. The material after treatment by the present invention meets or exceeds present government standards.
The oil removed from the vacuum filtration step is directed to an impingement tank ( 32 ) by an inlet manifold ( 34 ). The air/oil combination is drawn from the vacuum tray via numerous outlet port ( 36 ) through suitable conduits ( 37 ) into the inlet manifold through corresponding inlet ports ( 38 ). Air is drawn out of the impingement tank through an outlet manifold ( 40 ) comprising numerous outlet ports ( 42 ) through suitable conduits ( 43 ). Numerous vacuum pumps ( 44 ), in direct communication with the outlet manifold, provide the required vacuum. In one embodiment of the present invention as depicted in FIG. 1, there are 6 separate pumps pulling a total vacuum of from about 5 to about 9 inches of mercury. According to the present invention it was found that 6 such vacuum exhausters were needed to create the required vacuum to reduce the contaminating oil in the solid material to about 1%, or less than 1%. More or less vacuum exhausters can be used as needed. Air from the system is exhausted to the atmosphere. In one embodiment of the present invention the system also includes carbon filter in the exhaust (not shown).
The oil and possibly some fine solids collects in the bottom of the impingement tank in a separate but connected filtrate tank ( 45 ), shown in phantom, which contains a drain ( 46 ) to collect the oil for re use.
Depending upon the source of the material to be treated in may be necessary to include in the treatment system pre filters to remove large solids.
The apparatus described above can treat from about 3 to 9 tons per hour. The results will improve, lower residual oil left in the treated solids, if the system is run at from about 3 to 4 tons per hour. The apparatus described above can be scaled up or down to meet a higher of lower load requirement. In the apparatus described above the load can be increase by increasing the size of the belt filter and correspondingly increasing the number of vacuum pumps to provide approximately the same vacuum of from about 5 to about 9 inches of mercury.
In land based oil drilling, calcium chloride or potassium chloride is commonly used for structural stabilization of the well bore hole. Thus the oil contaminated material from a land based oil well will also have a high concentration of chloride ions that must be remove before the treated material can be released into the environment. At present, the province of Alberta requires that the chlorides be reduced to less than 2500 ppm. Thus, a further embodiment of the present invention provides a method and apparatus for removing chlorides from the treated material.
According to this further embodiment well bore cuttings from which the contaminate oil has been extracted is contacted with a solution of about 0.25% to about 15% by volume, of a surfactant in water. In one embodiment of the present invention the surfactant is dioctyl sodium sulfosuccinate.
The preferable temperature range of the water would be 10° C. to 100° C.
The volume of water required would be in the range of 1 to 20 times the volume of oil extracted well bore cuttings to be treated.
The preferable volume of water would be 3 times the volume of the oil extracted well bore cuttings to be treated.
The contact time would range from 1 minute to one hour.
The water is mechanically extracted from the cuttings by vacuum extraction, centrifugation, cyclones, etc.
The preferable mechanical extraction would be accomplished by vacuum extraction.
In one embodiment of the present invention, as shown in FIG. 2, the solids ( 50 ), previously treated to remove residual oil, are pumped by a pumping means ( 52 ) into a mixing tank ( 54 ). Into the mixing tank are pumped by a pumping means ( 56 ) separately, or as a mixture, the dioctyl sodium sulfosuccinate and hot water. The surfactant and water are held in one or more holding tanks ( 58 ), as is required. The treated material is then pumped by a further pumping means ( 60 ) onto a vacuum filter system ( 62 ), similar to that described above. The mud and cuttings ( 64 ), treated to remove both hydrocarbons and chlorides, are collected at the end of the vacuum belt. The waste water is pumped by a further pumping means ( 66 ) to a suitable water treatment system to remove the chlorides from the waste water.
EXAMPLES
Example 1
Removal of Oil and Chloride Ions from Land Based Well Bore Cuttings
Samples were obtained from PanCanadian. The concentration of oil in the samples prior to treatment was about 12.5%. The concentration of chloride in the untreated samples was about 16,900 mg/kg.
In this example the combination of surfactants for the removal of oil is as follows:
myristic alcohol 1 to 5% (w/w)
lauryl alcohol 1 to 5% (w/w)
ethoxylated lauryl alcohol 10 to 30% (w/w) dissolved in a sufficient quantity of the oil in the well bore cutting.
The sample, 100 ml, was treated with 15 ml of the surfactant/carrier oil combination. After mixing the oil was extracted using vacuum filtration generally as described above. The results are shown in Table 1.
TABLE 1
Summary of Test Results for Well
Bore Cutting from PanCanadian
% Oil or Chloride
Sample ID.
Description of Treatment Process
(mg/kg) in Sample
PanCanadian-1
No Treatment-Untreated analysis
12.5
PanCanadian-2
No Treatment-Untreated analysis
12.5
PanCanadian-3
No Treatment-Untreated Chloride
16,900
Analysis (mg/kg)
PanCanadian-2
Hydrocarbon extraction.
2.5
PanCanadian-2
Hydrocarbon extraction.
2.6
PanCanadian-2
Hydrocarbon extraction.
2.9
PanCanadian-2
Hydrocarbon extraction.
2.5
PanCanadian-2
Hydrocarbon extraction.
2.5
PanCanadian-2
Hydrocarbon extraction.
2.5
PanCanadian-2
Hydrocarbon extraction.
2.0
PanCanadian-2
Hydrocarbon extraction.
2.0
PanCanadian-3
Chloride reduction using only the
4,950
hydrocarbon extraction process
(chloride analysis mg/kg).
PanCanadian-3
Chloride reduction using the
2,600
hydrocarbon extraction process
followed by the chloride reduction
process (chloride analysis mg/kg).
Oil concentration was tested in an OFI 50 ml Retort Analyser, using standard procedures. Chloride analysis were done using standard techniques.
Example 2
Comparison of Different Oil Carriers and Addition of Underflow fines
To a 100 ml sample of land based cuttings was added 15 ml of the surfactant/oil carrier, containing 1% surfactant mixture, as in Example 1. The mixture was heated to about 40° C. and the oil removed by vacuum extraction, generally as described above.
Two types of oil carriers were used, either a synthetic oil, sold under the name IPAR3 (TM) and a non-synthetic oil, kerosene. As shown in Table 2 both are effective in reducing the oil concentration in the treated solids to less than 1%.
As previously discussed, as the drilling mud is used it is first cleaned before reuse by passing the mud through a screen to remove fines or cuttings. As the mud is re used the solid concentration increases. When the concentration becomes to high to allow reuse, the mud can be cleaned further by centrifugation to remove additional solids or fines. The solid material collected by centrifugation is know in the art as under flow fines. This example also shows the effectiveness of the present process in adding small amounts of the under flow fines to the cuttings, prior to cleaning by the present process. As seen in Table 2, 10% or 20% of under flow fines can be added to the system without detracting from the efficiency of the system.
TABLE 2
Summary of Results Using Different Oil
Carrier and Adding Underflow Fines
% Oil
Material Tested
water (ml)
Oil (ml)
remaining
(1) Cuttings Untreated
5
15
12.6
(2) Treated cuttings
2
1.5
0.9
(with IPAR3)
(3) Treated cuttings
1
0.5
0.29
(with Kerosene)
(4) Treated cuttings (with IPAR3)
1
2
1.18
(plus 20% underflow-fines)
(5) Treated cuttings (with Kerosene)
2
1.5
1.1
(plus 20% underflow-fines)
(6) Treated cuttings (with IPAR3)
1
1
0.58
(plus 10% underflow-fines)
(7) Treated cuttings (with Kerosene)
1
0.5
0.29
(plus 10% underflow-fines)
Example 3
A Comparison of Synthetic Oil and Non-Synthetic Oil in Off-Shore and On-Shore Samples
In this example three carrier oils were tested, IPAR3 (oil carrier # 1 ), diesel (oil carrier # 2 ) and a basically one to one mixture of diesel and IPAR3 (carrier oil # 3 ).
The testing conditions were as described in Example 2, except that the sample was not heated and the extraction procedure was centrifugation alone. In one of the tests the sample was pre conditioned with the surfactant in a diesel carrier oil, using the preconditioning step previously described (2Plus). The results of these test are shown below in Table 3.
TABLE 3
Summary of Test Results Using Different Carrier Oils
and On- and Off-Shore Samples
% Oil in
Carrier
centrifuge
% Solids in
Sample
Oil
discharge
recovered oil
Onshore
1
2.6
1.8
Onshore
3
2.04
1.7
Onshore
2
1.3
1.4
Onshore
2Plus
1.07
1.6
Offshore B
1
1.7
1.4
Offshore B
2
1.25
1.6
Offshore A
1
1.92
1.5
Offshore B
2
1.15
1.8
These results do not include the vacuum extraction step which could follow the centrifugation step and if included would most certainly remove the remaining oil to essentially a concentration lower than 1%.
Example 4
Pilot Plant Testing
The sample for this pilot plant testing was material from an open storage pit containing: well bore cuttings contaminated with underflow from drill mud centrifugation, some water based well cuttings along with drill mud tanks of low gravity solids as well as natural contamination.
The approximate daily input of the material to be treated is shown below in Table 4. Included in this Table is approximately 20 cubic meters of material that was treated in trial runs, before the equipment was running at capacity.
TABLE 4
Quantity of Material Treated
Date
Cubic Meters Treated
Tonnes Treated (SG 2.00)
Day 1
19
38
Day 2
16
32
Day 3
12.5
25
Day 4
13
26
Day 5
19
38
Day 6
18.5
37
Day 7
19
38
Day 8
15
30
Day 12
27
54
Day 13
23
46
Day 14
33
66
Day 15
15
30
Day 16
21
42
Day 17
29
58
Day 18
36
72
Day 19
37.5
75
Day 20
20
40
Day 21
26.5
53
Day 22
43.5
87
Day 23
20
40
Day 24
44
88
Day 25
47.5
95
Day 26
48
96
Trial Runs
20
40
Total # cubic meters treated =
Total # tonnes Treated =
623
1246
In this example the material to be treated was pre conditioned by adding 6 liters of the surfactant and oil carrier, containing 1% surfactant mixture, per ton of solid material. The pre conditioning step took place in the pump means, identified by reference numeral 12 in FIG. 1 . To the solid material, before entering the centrifuge, was added via a chemical feed, a 1% surfactant mixture in the oil carrier. Approximately 6 liters of surfactant mixture was added per minute. The solid material was added at a rate of about 9 tons per hour. This rate is approximately twice the capacity of the system designed to remove oil to a level of about 1%, or lower. During this test, it was required that the residual oil levels be below 3% by weight. If necessary we had the ability to maintain residual oil levels to less than 0.5%, but for the sake of expediency, and the volume of material to be treated, we elected to raise our residual by increasing our material processed. The test results are shown in Table 5.
Due to the high level of low gravity solids the sample was pre filtered to separate such solids from the other material to be treated. The sample was treated using the apparatus shown in FIG. 1 .
The total material treated was 623 cubic meters. To this material 17,025 liters of diesel carrier oil was used and 4800 liters of the surfactant mixture, as described in previous examples, were consumed. A total of about 208,519 liters of oil was recovered and 20 trucks (approximately 623 cubic meters) of treated solids was taken to land fill.
TABLE 5
Test Results
Date
Residual oil concentration
Pre - trial
0.66%, 0.92%
Pre - trial
2.5%
Pre - trial
2.8%
Day 1
2.5%, 2.5%, 2.7%
Day 2
2.77%, 2.48%, 2.13%
Day 3
2.16%, 2.18%, 2.2%
Day 4
1%, 0.78%, 1.8%, 1.6%, 0.78%, 1.55%, 1.37%
Day 5
1.4%, 1.6%, 2.26%, 1.55%, 1.57%, 2.4%, 1.57%
Day 6
1.6%, 1.55%, 2.5%
Day 7
1.3%, 3.2%, 2.66%, 1.5%, 3%, 2%
Day 8
1.37%, 1.54%
Day 12
1.24%, 0.9%, 2.6%, 2.26%, 2.4%
Day 13
2.24%, 3%, 3%
Day 14
1.55%, 1.9%, 2.66%
Day 15
1.9%
Day 16
1.92%, 2.8%, 1.92%
Day 17
1.9%, 1.2%, 2.24%
Day 18
0.96%, 0.918%, 1.9%, 1.26%, 1.27%
Day 19
1.9%, 1.6%, 1.4%, 1.55%, 0.92%
Day 20
0.9%, 1.85%, 2.3%, 1.55%
Day 21
0.6%, 2.3%
Day 22
1.26%, 1.24%, 2.9%, 1.58%, 1.24%
Day 23
1.4%, 1.57%, 1.92%, 1.57%, 2.25%, 2.6%
Day 24
0.94%, 1.9%, 2.26%, 2.26%
Day 25
1.26%, 1.92%, 1.94%, 1.59%, 1.6%
Day 26
1.22%, 2.76%, 1.41%, 1.4%, 1.4%, 1.4%
In order to access the efficiency of the pilot plant test, the system was slowed down to a feed rate of about 3 to 4 tons per hour, at selected times during the pilot plant test. During these periods the amount of oil remaining in the treated solids was approximately 0.6% (note the first sample on Day 21 for example).
The present invention has been described with regard to preferred embodiments. However, it will be understood to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described in the followings claims. | A method for chemically removing hydrocarbons from oil contaminated material is described. The method comprises contacting the material containing the oil with a combinations of surfactants in an oil carrier similar to or identical to the oil to be removed. This process avoids the use of water. Therefore the process does not compromise the quality of the oil by having water as a contaminant and thus eliminating the possibility of oil contaminated water getting into the environment. In certain examples, when the process is used to remove oil from land based well bore cuttings, the processed well bore cuttings contain high levels of chlorides, which is an environmental problem. In such examples the method also includes contacting the well bore cuttings with a solution of dioctyl sodium sulfosuccinate in water to reduce the chloride concentration. An apparatus designed for this purpose is also described. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on application No. 2003-44403 filed in the Korean Intellectual Property Office on Jul. 1, 2003, the disclosure of which is incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a negative electrode for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery comprising the same, and more particularly, to a negative electrode for a lithium secondary battery having improved cycle-life characteristics, a method of preparing the same, and a lithium secondary battery comprising the same.
[0004] 2. Description of the Related Art
[0005] With an increase in the use of portable electronic equipment, the demand for a battery which is lighter in weight and has a higher capacity has also increased. A lithium metal secondary battery in which lithium metals are used as a negative active material is a strong candidate for satisfying the demand, since it is expected to have a high capacity. Among the candidates, a lithium-sulfur battery in which the sulfur-based material is used as a positive active material is most attractive.
[0006] The lithium-sulfur batteries are secondary batteries composed of a positive active material of a sulfur-based compound having sulfur-sulfur bonds as a positive active material, and a negative active material such as an alkaline metal or lithium metal that reversibly intercalates metal ions. The batteries produce and store electrical energy as a result of a redox reaction in which the oxidation number of sulfur is decreased and sulfur-sulfur bonds are cleaved upon the reduction reaction (discharge), and the oxidation number of sulfur is increased and sulfur-sulfur bonds are regenerated upon the oxidation reaction (charge).
[0007] Lithium metal is widely utilized as a negative active material since it is light in weight and has a high energy density. However, the lithium metal may cause problems in that the cycle life characteristics of the battery are deteriorated due to a high reactivity of the lithium metal. A protective layer has been suggested to protect the surface of the lithium metal.
[0008] The protective layer may be exemplified by an inorganic protective layer and a polymer protective layer. With respect to the protective layers, a lithium ion conductive material of LIPON (Lithium Phosphorus Oxy-Nitride) has been actively researched. The LIPON protective layer is formed by a sputtering process under a nitrogen gas atmosphere. When it is desirable to form a lithium layer directly on the surface of the lithium metal, the lithium metal may react with the nitrogen gas, thus generating an adduct of a black porous lithium composite compound which has a poor binding strength to the surface of the lithium metal.
[0009] Further, when the protective layer is composed of the polymer, the lithium metal may react with the organic solvent used to form the protective layer.
[0010] To avoid the above problems, U.S. Patent Laid-open Publication No. 2002/0012846 A1 (MOLTECH CORPORATION, USA) discloses a temporary protective layer to protect the surface of the lithium metal during preparation of a protective layer on the surface of the lithium metal. The temporary protective layer comprises a material generated from a reaction of the lithium and a gaseous material such as the gas used in a plasma CO 2 treatment, or a material that readily alloys with the lithium, for example, copper. However, the temporary protective layer generated from the reaction with the CO 2 gas is too thin (less than 20 Å) to provide adequate protection to the surface of the lithium. Alternatively, the temporary protective layer formed from the metal that may alloy with the lithium metal causes a huge volume variation, rendering the structure unstable.
SUMMARY OF THE INVENTION
[0011] It is an aspect of the present invention to prevent generation of an adduct of a black porous lithium composite compound which has an ineffective binding strength to the surface of the lithium when a protective layer such as LIPON is formed under a nitrogen gas atmosphere, and to provide a negative electrode of a lithium secondary battery, including a pretreatment layer to prevent a direct contact between the lithium and a solvent used to form a polymer protective layer.
[0012] It is another aspect of the present invention to provide a method of preparing a negative electrode of a lithium secondary battery wherein the negative electrode includes a pretreatment layer prepared by using a simple process.
[0013] It is still another aspect of the present invention to provide a lithium secondary battery including the negative electrode.
[0014] To accomplish the above and/or other aspects, the present invention provides a negative electrode of a lithium secondary battery, including a negative active material layer and a lithium ion conductive layer formed on the negative active material layer, wherein the lithium ion conductive layer includes a compound represented by the following Formula 1:
Li x CO y (1)
wherein 1<x<3, and 2<y<4.
[0016] The present invention further provides a method of preparing a negative electrode of a lithium secondary battery, wherein the method includes depositing a lithium ion conductive material on a negative active material layer under an inert gas atmosphere to provide a lithium ion conductive layer formed on the negative active material layer, and wherein the lithium ion conductive layer includes a compound represented by the Formula 1.
[0017] In addition, the present invention still further provides a lithium secondary battery that utilizes a negative electrode that includes a negative active material layer and a lithium ion conductive material layer formed on the negative active material, wherein the lithium ion conductive layer includes a compound represented by the Formula 1; a positive electrode that includes a positive active material selected from the group consisting of elemental sulfur (S 8 ), a sulfur-based compound, and a mixture thereof; and an electrolyte.
[0018] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0020] FIG. 1 is a schematic view showing an embodiment of a structure of the lithium secondary battery of the present invention;
[0021] FIG. 2 is a graph showing cyclic-life characteristics of lithium-sulfur cells of Examples 1-3, Reference Example 1, and Comparative Example 1;
[0022] FIG. 3 is a SEM micrograph of the electrode of Example 1 after it was immersed in a dimethoxy ethane solution for 5 minutes and then taken therefrom; and
[0023] FIG. 4 is a SEM micrograph of the electrode of Comparative Example 2 after it was immersed in a dimethoxy ethane solution for 5 minutes and then taken therefrom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
[0025] Generally, lithium metal is known to be used to provide a negative active material for a lithium metal battery, and particularly, for a lithium-sulfur battery due to its properties such as its light weight and high energy density. Nonetheless, lithium metal has the disadvantage of having an excessively high reactivity. To solve the problems caused by the high reactivity, studies to provide a protective layer of the lithium metal are being actively pursued. Although a polymer organic protective layer has generally been suggested for such a protective layer, it also causes problems in that the lithium metal may react with the organic solvent used to provide the protection layer.
[0026] During research to find a temporary protection layer to prevent contact between the lithium metal and the organic solvent used to form a protective layer, the present inventors found that contact between the negative active material layer and the organic solvent of the protective layer may be prevented and that the cycle-life may be improved by forming the compound represented by Formula 1 between the negative active material and the organic protective layer by the sputtering technique, as set forth below in the present invention:
Li x CO y (1)
wherein 1<x<3, and 2<y<4.
[0028] The compound of Formula 1 is a lithium ion conductive material. The lithium ion conductive layer obtained from the compound should have an ion conductivity greater than or equal to 1×10 −12 S/cm. A thicker layer may be provided depending upon the higher ion conductivity, and thus, a desirable pretreatment layer is provided. Generally, ion conductivity of 1×10 −12 S/cm has been considered to exert an unfavorable influence on battery performance, but the lithium ion conductive layer formed by depositing, typically sputtering, the compound represented by the Formula 1 according to the present invention may improve the cycle-life characteristics of the battery. However, the improvement of the cycle-life characteristics is not exhibited when the layer is formed by a gas depositing process instead of a sputtering process.
[0029] The effect on the cycle-life characteristics is attributed to uniformly generated cracks on the lithium ion conductive layer during the charge and the discharge intervals, and thus it facilitates uniform movement of the lithium ions on the surface of the lithium and inhibits development of dendrites or generating dead lithium in which the lithium is concentrated on the inside. Further, the layer may directly prevent contact between the negative active layer and the organic solvent so that the lithium loss due to the reaction with the organic solvent is prevented.
[0030] Since the conventional inorganic protective layer of LIPON, which is utilized to prevent contact between the negative active material layer and the organic solvent for forming an organic protective layer, imparts an unfavorable influence on the cycle-life characteristics when it is used alone, the organic protective layer is required for the negative electrode. However, according to the present invention, the lithium ion conductive layer does not require an additional organic protective layer to provide a negative electrode. Nevertheless, where desired, the negative electrode of the present invention may further include the organic protective layer.
[0031] When the ion conductivity of the lithium ion conductive layer is less than 1×10 −12 S/cm, the lithium ions are not readily transmitted.
[0032] The lithium ion conductive layer typically has a thickness of 20 to 300 Å. When the thickness is less than 20 Å, contact between the negative active material layer and the organic solvent is difficult to prevent completely, while when the thickness is more than 300 Å, the ion conductivity of the lithium ion conductive layer is lowered so that an overvoltage is applied to prevent impairment of the battery performance.
[0033] The negative electrode may further include a protective layer on the lithium ion conductive layer. The protective layer may comprise the organic material or the polymer. The organic material may include, but is not limited to, lithium silicate, lithium borate, lithium aluminate, lithium phosphate, lithium phosphorus oxynitrate, lithium silicosulfide, lithium germanous sulfide, lithium lanthanum oxide, lithium tantalum oxide, lithium niobium oxide, lithium titanium oxide, lithium borosulfide, lithium aluminosulfide, lithium phosphorosulfide, and a mixture thereof. The polymer may include, but is not limited to, a polymer polymerized with at least one acrylate monomer selected from the group consisting of alkyl acrylate, glycol acrylate, and polyglycol acrylate.
[0034] According to the present invention, the negative active material layer may comprise a negative active material of a lithium metal or a lithium alloy. The lithium alloy may include, but is not limited to, a lithium tin alloy, and any conventional lithium alloy that may act as a negative active material in the lithium-sulfur battery.
[0035] The negative electrode of the present invention is prepared by depositing the compound represented by the following Formula 1 under an inert atmosphere using the target to provide a lithium ion conductive layer formed on the negative active material layer:
Li x CO y (1)
wherein 1<x<3, and 2<y<4.
[0037] The target may include a lithium ion conductive material which is the same as the compound represented by the Formula 1.
[0038] The inert atmosphere may include, without limitation, any conventional gas atmosphere used for the sputtering process, as long as the gas does not participate in the reaction, for example, an argon gas atmosphere may be utilized.
[0039] The deposition process is typically a sputtering process. The sputtering process may be carried out for a sufficient time to provide a lithium ion conductive layer in a thickness of 20 to 300 Å on the negative active material layer. The sputtering process time depends upon the sputtering system, that is, depending upon the equipment scale, the target size, the power to be applied, and the like, but the sputtering process is generally continued for about 10 minutes to 5 hours, until the desirable thickness of the lithium ion conductive layer is obtained on the negative active material layer.
[0040] One embodiment of the lithium secondary battery, including the negative electrode of the present invention, is shown in FIG. 1 . The battery includes a positive electrode 3 , a negative electrode 2 , a separator 4 interposed between the positive electrode 3 and the negative electrode 2 , and an electrolyte between the positive electrode 3 and the negative electrode 2 . The battery further includes a battery case 5 and a sealing portion 6 sealing the battery case 5 . The configuration of the rechargeable lithium battery is not limited to the structure shown in FIG. 1 , as it can be readily modified into a prismatic, cylindrical, or pouch type battery as is well understood in the related art.
[0041] The positive electrode includes any positive active material of elemental sulfur (S 8 ), a sulfur based compound, or a mixture thereof. The sulfur-based compound includes at least one compound selected from the group consisting of Li 2 S n (n≧1), an organic sulfur compound, and a carbon-sulfur polymer ((C 2 S x ) n : x=2.5˜50, n≧2). However, it may include any conventional positive active materials used for a lithium secondary battery, for example, a lithium transit metal oxide.
[0042] The lithium secondary battery of the present invention includes an electrolyte, and the electrolyte includes an organic solvent and an electrolyte salt.
[0043] The organic solvent may be a single solvent or a mixture of two or more organic solvents. If the organic solvent is a mixture of two or more organic solvents, it is preferable to select at least one solvent from at least two groups of a weak polar solvent group, a strong polar solvent group, and a lithium metal protection solvent group.
[0044] The term “weak polar solvent,” as used herein, refers to a solvent that may dissolve elemental sulfur, and has a dielectric coefficient of less than 15. The weak polar solvent may include aryl compounds, bicyclic ether, and acyclic carbonate compounds. The term “strong polar solvent,” as used herein, refers to a solvent that may dissolve lithium polysulfide, and has a dielectric coefficient of more than 15. The strong polar solvent may include bicyclic carbonate compounds, sulfoxide compounds, lactone compounds, ketone compounds, ester compounds, sulfate compounds, or sulfite compounds.
[0045] The term “lithium protection solvent,” as used herein, refers to a solvent which forms an effective protective layer, i.e., a stable solid-electrolyte interface (SEI) layer on the lithium surface, and shows an effective cyclic efficiency greater than or equal to 50%. The lithium protection solvent is selected from saturated ether compounds, unsaturated ether compounds, or heterocyclic compounds including N, O, and S, and a composite thereof.
[0046] Examples of the weak polar solvents include xylene, dimethoxyethane, 2-methyltetrahydrofurane, diethyl carbonate, dimethyl carbonate, toluene, dimethyl ether, diethyl ether, diglyme, and tetraglyme.
[0047] Examples of the strong polar solvents include hexamethyl phosphoric triamide, γ-butyrolactone, acetonitrile, ethylene carbonate, propylene carbonate, N-methylpyrrolidone, 3-methyl-2-oxazolidone, dimethyl formamide, sulfolane, dimethyl acetamide, dimethyl sulfoxide, dimethyl sulfate, ethylene glycol diacetate, dimethyl sulfite, and ethylene glycol sulfite.
[0048] Examples of the lithium protection solvents include tetrahydrofuran, ethylene oxide, dioxolane, 3,5-dimethylisoxazole, 2,5-dimethyl furan, furan, 2-methyl furan, 1,4-oxane, and 4-methyldioxolane.
[0049] The electrolyte salt may include at least one lithium salt selected from lithium fluoro methane sulfonimide or lithium triplate. The lithium salt may be added in a concentration of between 0.6 and 2.0 M, preferably between 0.7 and 1.6 M. When the concentration of the lithium salt is less than 0.6 M, the conductivity of the electrolyte is too low to maintain the electrolyte performance, while when it is more than 2.0 M, the viscosity of the electrolyte is too high to facilitate moving the lithium ions.
[0050] Hereinafter, the present invention will be explained in detail with reference to examples. These examples, however, should not in any sense be interpreted as limiting the scope of the present invention.
COMPARATIVE EXAMPLE 1
[0051] Cu was thermally deposited on a clear, cleaned glass to about 3000 Å. To the obtained glass/copper substrate, lithium was thermally deposited to 20 μm to provide a negative electrode.
[0052] 75% by weight of an elemental sulfur (S 8 ) active material, 12% by weight of a polyethylene oxide binder, and 13% by weight of a carbon black conductive agent were mixed to provide a positive electrode.
[0053] Using the lithium negative electrode, the positive electrode, an electrolyte, and a separator, the lithium-sulfur cell was fabricated. The separator was prepared as a three-layered film with a thickness of 16 μm from polypropylene/polyethylene/polypropylene. The electrolyte was dimethoxy ethane/diglyme/dioxolane (4:4:2 in volume ratio) in which 1M LiN(SO 2 CF 3 ) 2 was dissolved.
COMPARATIVE EXAMPLE 2
[0054] Cu was thermally deposited to about 3000 Å as in Comparative Example 1, on a clear, cleaned glass. Lithium was thermally deposited to 20 μm on the obtained glass/Cu substrate.
[0055] Subsequently, the glass/Cu substrate was treated with plasma CO 2 to form a 10 Å thick Li 2 CO 3 layer on the lithium-deposited substrate to provide a negative electrode having the glass/Cu/lithium/Li 2 CO 3 layers. The thickness was measured according to AFM (atomic force microscopy).
[0056] A lithium-sulfur cell was fabricated using the negative electrode by the same procedure as in Comparative Example 1.
EXAMPLE 1
[0057] Cu was thermally deposited to about 3000 Å as in Comparative Example 1 on a clear, cleaned glass. Lithium was thermally deposited to 20 μm on the obtained glass/Cu substrate.
[0058] Subsequently, the glass/Cu substrate was subjected to the RF supporting process using a 2 inch, 99.9% purity Li 2 CO 3 target to form a 96 Å thick Li 2 CO 3 layer on the lithium-deposited substrate to provide a negative electrode having the glass/Cu/lithium/Li 2 CO 3 layers. The thickness was measured according to AFM (atomic force microscopy).
[0059] A lithium-sulfur cell was fabricated using the negative electrode by the same procedure as in Comparative Example 1.
EXAMPLE 2
[0060] A lithium-sulfur cell was fabricated by the same procedure as in Example 1, except that a Li 2 CO 3 layer was formed to a thickness of 30 Å.
EXAMPLE 3
[0061] A lithium-sulfur cell was fabricated by the same procedure as in Example 1, except that a Li 2 CO 3 layer was formed to a thickness of 300 Å.
REFERENCE EXAMPLE 1
[0062] A lithium-sulfur cell was fabricated by the same procedure as in Example 1, except that a Li 2 CO 3 layer was formed to a thickness of 400 Å.
[0063] Cells obtained from Examples 1 to 3, Reference Example 1, and Comparative Example 1 were discharged at 0.5 C and 1.5 V and let stand for 5 minutes, then charged at 0.2 C and 2.8 V to determine the cycle-life characteristics, over 60 cycles, and the results are shown in FIG. 2 . As shown in FIG. 2 , it was demonstrated that the cell of Example 1 having the Li 2 CO 3 layer had more improved cycle-life characteristics than those of the cell of Comparative Example 1 having no Li 2 CO 3 . In addition, the cell of Reference Example 1 with a Li 2 CO 3 layer thickness of more than 300 Å was demonstrated to have remarkably deteriorated cycle-life characteristics over the 60 cycles. It was estimated that since the Li 2 CO 3 layer itself has poor ion conductivity of 1×10 −12 , it cannot facilitate moving the lithium ions.
[0064] FIGS. 3 and 4 respectively show SEM (Scanning Electron Microscopy) micrographs in which the electrodes of Example 1 and Comparative Example 2 were immersed in dimethoxy ethane solvent for 5 minutes and then taken out. As shown in FIGS. 3 and 4 , a thick Li 2 CO 3 layer of Example 1 formed by sputtering imparts an effective protective layer to block the solvent, while a thin Li 2 CO 3 layer of Comparative Example 2 formed by the gas reaction does not block the solvent.
[0065] As described in the above, the negative electrode for a lithium secondary battery of the present invention has a lithium ion conductive layer with an optimal thickness, so that it prevents the reaction between the negative active material and the electrolyte, and cycle-life characteristics are improved.
[0066] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | A negative electrode of a lithium secondary battery, a method of fabricating the same, and a lithium secondary battery including the same utilize, in the negative electrode, a negative active material layer and a lithium ion conductive layer formed on the negative active material layer, wherein the lithium ion conductive layer includes a compound represented by the following Formula 1:
Li x CO y (1)
wherein 1<x<3, and 2<y<4. | 7 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to tricyclic compounds. These compounds have selective acid pump inhibitory activity. The present invention also relates to a pharmaceutical composition, method of treatment and use, comprising the above derivatives for the treatment of disease conditions mediated by acid pump modulating activity; in particular acid pump inhibitory activity.
[0002] It has been well established that proton pump inhibitors (PPIs) are prodrugs that undergo an acid-catalyzed chemical rearrangement that permits them to inhibit H + /K + -ATPase by covalently binding to its Cystein residues (Sachs, G. et. al., Digestive Diseases and Sciences, 1995, 40, 3S-23S; Sachs et al., Annu Rev Pharmacol Toxicol, 1995, 35, 277-305.). However, unlike PPIs, acid pump antagonists inhibit acid secretion via reversible potassium-competitive inhibition of H + /K + -ATPase. SCH28080 is one of such reversible inhibitors and has been studied extensively. Other newer agents (revaprazan, soraprazan, AZD-0865 and CS-526) have entered in clinical trials confirming their efficacy in human (Pope, A.; Parsons, M., Trends in Pharmacological Sciences, 1993, 14, 323-5; Vakil, N., Alimentary Pharmacology and Therapeutics, 2004, 19, 1041-1049.). In general, acid pump antagonists are found to be useful for the treatment of a variety of diseases, including gastrointestinal disease, gastroesophageal disease, gastroesophageal reflux disease (GERD), laryngopharyngeal reflux disease, peptic ulcer, gastric ulcer, duodenal ulcer, non-steroidal anti-inflammatory drug (NSAID)-induced ulcers, gastritis, infection of Helicobacter pylori , dyspepsia, functional dyspepsia, Zollinger-Ellison syndrome, non-erosive reflux disease (NERD), visceral pain, cancer, heartburn, nausea, esophagitis, dysphagia, hypersalivation, airway disorders or asthma (hereinafter, referred as “APA Diseases”; Kiljander, Toni O, American Journal of Medicine, 2003, 115 (Suppl. 3A), 65S-71S; Ki-Baik Hahm et al., J. Clin. Biochem. Nutr., 2006, 38, (1), 1-8.).
[0003] WO04/87701 refers to some compounds, such as tricyclic benzimidazole derivatives, as acid pump antagonists.
[0004] There is a need to provide new acid pump antagonists that are good drug candidates and address unmet needs by PPIs for treating diseases. In particular, preferred compounds should bind potently to the acid pump whilst showing little affinity for other receptors and show functional activity as inhibitors of acid-secretion in stomach. They should be well absorbed from the gastrointestinal tract, be metabolically stable and possess favorable pharmacokinetic properties. They should be non-toxic. Furthermore, the ideal drug candidate will exist in a physical form that is stable, non-hygroscopic and easily formulated.
SUMMARY OF THE INVENTION
[0005] In this invention, it has now been found out that the new class of tricyclic compounds having a substituted alkyl group at 1 position show acid pump inhibitory activity and good bioavailability as drug candidates, and thus are useful for the treatment of disease conditions mediated by acid pump inhibitory activity such as APA Diseases.
[0006] The present invention provides a compound of the following formula (I):
[0000]
[0000] or a pharmaceutically acceptable salt thereof, wherein;
R 1 represents a C 1 -C 6 alkyl group being unsubstituted or substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group, a hydroxy-substituted C 3 -C 7 cycloalkyl group, a hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group, an aryl group, a hydroxy-substituted aryl group, a heteroaryl group and a halogen-substituted heteroaryl group; R 2 represents a hydrogen atom or a C 1 -C 6 alkyl group being unsubstituted or substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group and a C 1 -C 6 alkoxy group; R 3 and R 4 independently represent a hydrogen atom, or a C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or heteroaryl group being unsubstituted or substituted with 1 to 3 substituents independently selected from the group consisting of a deuterium, a halogen atom, a hydroxy group, a C 1 -C 6 alkoxy group and a C 3 -C 7 cycloalkyl group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form a 4 to 6 membered heterocyclic group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group, and a hydroxy-C 1 -C 6 alkyl group; A represents an aryl or heteroaryl group being unsubstituted or substituted with 1 to 5 substituents independently selected from the group consisting of a halogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, —NR 5 SO 2 R 6 and —CONR 7 R 8 ; R 5 , R 7 and R 8 independently represent a hydrogen atom or a C 1 -C 6 alkyl group; R 6 represents a C 1 -C 6 alkyl group; and E represents an oxygen atom or NH.
[0014] Also, the present invention provides a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, together with a pharmaceutically acceptable carrier for said compound.
[0015] Also, the present invention provides a pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, further comprising other pharmacologically active agent(s).
[0016] Also, the present invention provides a method for the treatment of a condition mediated by acid pump modulating activity in a mammalian subject including a human, which comprises administering to a mammal in need of such treatment a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein.
[0017] Examples of conditions mediated by acid pump modulating activity include, but are not limited to, APA Diseases.
[0018] Further, the present invention provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, for the manufacture of a medicament for the treatment of a condition mediated by acid pump inhibitory activity.
[0019] Further, the present invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, for use in medicine.
[0020] Preferably, the present invention also provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, for the manufacture of a medicament for the treatment of diseases selected from APA Diseases.
[0021] The compounds of the present invention may show good acid pump inhibitory activity, less toxicity, good absorption, good distribution, good solubility, less protein binding affinity other than acid pump, less drug-drug interaction and good metabolic stability.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In the compounds of the present invention:
[0023] Where R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and the substituents of the 4 to 7 membered heterocyclic group and A are the C 1 -C 6 alkyl group, this C 1 -C 6 alkyl group may be a straight or branched chain group having one to six carbon atoms, and examples include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, 1-ethylpropyl and hexyl. Of these, C 1 -C 2 alkyl is more preferred; methyl is more preferred.
[0024] Where R 3 and R 4 are the C 3 -C 7 cycloalkyl group, this represents cycloalkyl group having three to seven carbon atoms, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl. Of these, C 3 -C 5 cycloalkyl group is preferred; cyclopropyl is more preferred.
[0025] Where the substituents of R 1 , R 3 and R 4 are the C 1 -C 6 alkoxy group, this represents the oxygen atom substituted with the said C 1 -C 6 alkyl group, and examples include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy and hexyloxy. Of these, a C 1 -C 4 alkoxy is preferred; a C 1 -C 2 alkoxy is preferred; methoxy is more preferred.
[0026] Where R 3 and R 4 taken together with the nitrogen atom to which they are attached form a 4 to 7 membered heterocyclic group, this 4 to 7 membered heterocyclic group represents a saturated heterocyclic group having three to six ring atoms selected from carbon atom, nitrogen atom, sulfur atom and oxygen atom other than said nitrogen atom, and examples include, but are not limited to, azetidinyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, piperidyl, piperazinyl, hexahydroazepinyl, hexahydrodiazepinyl, morpholino, thiomorpholino and homomorpholino. Of these, azetidinyl, pyrrolidinyl, morpholino and homomorpholino are preferred; morpholino is more preferred.
[0027] Where the substituent of the 4 to 7 membered heterocyclic group or A is a hydroxy-C 1 -C 6 alkyl group, this represents said C 1 -C 6 alkyl group substituted with a hydroxy group, and examples include, but are not limited to, hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl 3-hydroxypropyl, 2-hydroxypropyl, 2-hydroxy-1-methylethyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl, 3-hydroxy-2-methylpropyl, 3-hydroxy-1-methylpropyl, 5-hydroxypentyl and 6-hydroxyhexyl. Of these, hydroxy-C 1 -C 3 alkyl is preferred; hydroxymethyl is more preferred.
[0028] Where A and the substituents of R 1 are an aryl group, these may be phenyl, naphtyl or anthracenyl. Of these, phenyl is preferred.
[0029] Where the substituents of R 3 , R 4 and A are a halogen atom, they may be a fluorine, chlorine, bromine or iodine atom. Of these, a fluorine atom and a chlorine atom are preferred.
[0030] Where the substituent of R 1 is a hydroxy-substituted aryl group, this hydroxy-substituted aryl group represents an aryl group which is substituted with hydroxy group(s) and the aryl group is aforementioned above. Examples include, but not limited to, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2,3-dihydroxyphenyl, 2,4-dihydroxyphenyl, 3,5-dihydroxyphenyl, 1-hydroxynaphthyl, 2-hydroxynaphthyl, 1-hydroxyanthracenyl. Of these, 3-hydroxyphenyl is preferred.
[0031] Where A, R 3 , R 4 or the substituents of R 1 are a heteroaryl group, this represents 5 to 6-membered ring containing at least one hetero atom selected from N, O and S, and examples include, but not limited to, 2-thienyl, 2-thiazolyl, 4-thiazolyl, 2-furyl, 2-oxazolyl, 1-pyrazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrazinyl and 2-pyrimidinyl. Of these, the heteroaryl group containing at least one nitrogen atom is preferred; 2-thiazolyl, 4-thiazolyl and 1-pyrazolyl are more preferred for the substituent of R 1 ; 2-pyridyl, 3-pyridyl and 4-pyridyl are more preferred for A.
[0032] Where the substituent of R 1 is a hydroxy-substituted C 3 -C 7 cycloalkyl group, this hydroxy-substituted C 3 -C 7 cycloalkyl group represents a C 3 -C 7 cycloalkyl group which is substituted with hydroxy group(s) and the C 3 -C 7 cycloalkyl is aforementioned above. Examples of a hydroxy-substituted C 3 -C 7 cycloalkyl group include, but are not limited to, 1-hydroxycyclopropyl, 2-hydroxycyclopropyl, 1-hydroxycyclobutyl, 2-hydroxycyclobutyl, 2,3-dihydroxycyclobutyl 2-hydroxycyclopentyl, 3-hydroxycyclopentyl, 1-hydroxycyclohexyl, 2-hydroxycyclohexyl, 3-hydroxycyclohexyl, 4-hydroxycyclohexyl, 2,4-dihydroxycyclohexyl, 3,5-dihydroxycyclohexyl, 1-hydroxycycloheptyl, 2-hydroxycycloheptyl, 3-hydroxycycloheptyl and 4-hydroxycycloheptyl. Of these, hydroxy-substituted C 3 -C 5 cycloalkyl is preferred; 1-hydroxycyclopropyl is more preferred.
[0033] Where the substituent of R 1 is a hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group, this hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group represents a C 3 -C 7 cycloalkyl group which is substituted with hydroxy-C 1 -C 6 alkyl group(s), and the hydroxy-C 1 -C 6 alkyl and the C 3 -C 7 cycloalkyl are aforementioned above. Examples of a hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group include, but are not limited to, 1-hydroxymethylcyclopropyl, 1-(2-hydroxyethyl)-cyclopropyl, 2-hydroxymethylcyclopropyl, 1-hydroxymethylcyclobutyl, 2-hydroxymethylcyclobutyl, 2,3-bis(hydroxymethyl)cyclobutyl, 1-hydroxymethylcyclopentyl, 2-hydroxymethylcyclopentyl, 3-hydroxymethylcyclopentyl, 1-hydroxymethylcyclohexyl, 2-hydroxymethylcyclohexyl, 3-hydroxymethylcyclohexyl, 4-hydroxymethylcyclohexyl, 1-hydroxymethylcycloheptyl, 2-hydroxymethylcycloheptyl, 3-hydroxymethylcycloheptyl and 4-hydroxymethylcycloheptyl. Of these, hydroxy-C 1 -C 3 alkyl-substituted C 3 -C 5 cycloalkyl is preferred; 1-hydroxymethylcyclopropyl and 1-(2-hydroxyethyl)-cyclopropyl are more preferred.
[0034] Where the substituent of R 1 is a halogen-substituted heteroaryl group, this halogen-substituted heteroaryl group represents a heteroaryl group which is substituted with halogen atom(s), and the halogen atom and the heteroaryl are aforementioned above. Examples of a halogen-substituted heteroaryl group include, but are not limited to, 4-fluoro-2-thienyl, 4-fluoro-2-thiazolyl, 2-fluoro-4-thiazolyl, 4-fluoro-2-furyl, 4-fluoro-2-oxazolyl, 4-fluoro-1-pyrazolyl, 4-fluoro-2-pyridyl, 5-fluoro-3-pyridyl, 3-fluoro-4-pyridyl, 3,4-difluoro-2-pyridyl, 3,5-difluoro-2-pyridyl, 5-fluoro-2-pyrazyl, 5-fluoro-2-pyrimidinyl, 4-chloro-2-thienyl, 4-chloro-2-thiazolyl, 2-chloro-4-thiazolyl, 4-chloro-2-furyl, 4-chloro-2-oxazolyl, 4-chloro-1-pyrazolyl, 4-chloro-2-pyridyl, 5-chloro-3-pyridyl, 3-chloro-4-pyridyl, 3,4-dichloro-2-pyridyl, 3,5-dichloro-2-pyridyl, 5-chloro-2-pyrazyl and 5-chloro-2-pyrimidinyl. Of these, 3,5-difluoro-2-pyridyl is preferred.
[0035] Where the substituent of A is a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, this C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group represents a C 1 -C 6 alkyl group which is substituted by C 1 -C 6 alkoxy group(s) and the C 1 -C 6 alkoxy and the C 1 -C 6 alkyl are aforementioned above. Examples of a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group include, but are not limited to, methoxymethyl, 2-methoxyethyl, 3-methoxypropyl, 4-methoxybutyl, 5-methoxypentyl, 6-methoxyhexyl, 1-ethoxymethyl, 2-ethoxyethyl, 3-ethoxypropyl, 4-ethoxybutyl, 5-ethoxypentyl. Of these, C 1 -C 3 alkoxy-substituted C 1 -C 3 alkyl is preferred; methoxymethyl is more preferred.
[0036] Where the substituents of the 4 to 6 membered heterocyclic group are a C 1 -C 6 acyl group, this represents a carbonyl group substituted with hydrogen atom or the said C 1 -C 5 alkyl group, and examples include, but are not limited to, a formyl, acetyl, propionyl, butyryl, pentanoyl and hexanoyl. Of these, C 2 -C 6 acyl is preferred and acetyl is more preferred.
[0037] The term “treating” and “treatment”, as used herein, refers to curative, palliative and prophylactic treatment, including reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such disorder or condition.
[0038] Preferred classes of compounds of the present invention are those compounds of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, in which:
(a) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group, a hydroxy-substituted C 3 -C 7 cycloalkyl group, a hydroxy-C 1 -C 6 alkyl-substituted C 3 -C 7 cycloalkyl group, an aryl group, a hydroxy-substituted aryl group, a heteroaryl group and a halogen-substituted heteroaryl group; (b) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; (c) R 1 is a C 1 -C 6 alkyl group being substituted with a hydroxy group, C 1 -C 6 alkoxy group or a heteroaryl group; (d) R 1 is a C 2 -C 3 alkyl group being substituted with a hydroxy group, a C 1 -C 3 alkoxy group, an isoxazole group, a thiazolyl group or a pyrazolyl group; (e) R 1 is a C 2 -C 3 alkyl group being substituted with a hydroxy group, a methoxy group or an isoxazole group; (f) R 2 is a C 1 -C 6 alkyl group being unsubstituted or substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group and a C 1 -C 6 alkoxy group; (g) R 2 is a C 1 -C 6 alkyl group; (h) R 2 is a C 1 -C 3 alkyl group; (i) R 2 is a methyl group; (j) R 3 and R 4 are independently a hydrogen atom, or a C 1 -C 6 alkyl, C 3 -C 7 cycloalkyl or heteroaryl group being unsubstituted or substituted with 1 to 3 substituents independently selected from the group consisting of a deuterium, a halogen atom, a hydroxy group, a C 1 -C 6 alkoxy group and a C 3 -C 7 cycloalkyl group; (k) R 3 and R 4 are independently a C 1 -C 6 alkyl group being unsubstituted or substituted with one substituent selected from the group consisting of a hydroxy group and a C 1 -C 6 alkoxy group or —CD 3 ; (l) R 3 and R 4 are independently a hydrogen atom, a C 1 -C 3 alkyl group being unsubstituted or substituted with a hydroxy group or —CD 3 ; (m) R 3 and R 4 are independently a hydrogen atom, a methyl group, —CD 3 or 2-hydroxyethyl group; (n) R 3 and R 4 are independently a methyl group, —CD 3 or 2-hydroxyethyl group; (o) R 3 and R 4 taken together with the nitrogen atom to which they are attached form a 4 to 6 membered heterocyclic group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group, and a hydroxy-C 1 -C 6 alkyl group; (p) R 3 and R 4 taken together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; (q) R 3 and R 4 taken together with the nitrogen atom to which they are attached form a piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group and a hydroxy-C 1 -C 3 alkyl group; (r) R 3 and R 4 taken together with the nitrogen atom to which they are attached form a morpholino group; (s) A is an aryl group being unsubstituted or substituted with 1 to 5 substituents independently selected from the group consisting of a halogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, —NR 5 SO 2 R 6 and —CONR 7 R 8 ; (t) A is an aryl group being unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group and a hydroxy-C 1 -C 6 alkyl group; (u) A is an aryl group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of hydrogen atom, a fluorine atom, a methyl group and a hydroxymethyl group; (v) A is an aryl group being unsubstituted or substituted with a halogen atom; (w) A is a phenyl I group being unsubstituted or substituted with a fluorine atom; (x) R 5 is a hydrogen atom or a C 1 -C 6 alkyl group; (y) R 5 is a hydrogen atom or a methyl group; (z) R 6 is a C 1 -C 4 alkyl group; (aa) R 6 is a methyl group (bb) R 7 is a hydrogen atom or a C 1 -C 6 alkyl group; (cc) R 7 is a hydrogen atom or a methyl group; (dd) R 8 is a hydrogen atom or a C 1 -C 6 alkyl group; (ee) R 8 is a hydrogen atom or a methyl group; (ff) E is an oxygen atom.
[0071] Of these classes of compounds, any combination among (a) to (ff) is also preferred.
[0072] Preferred compounds of the present invention are those compounds of formula (I) or a pharmaceutically acceptable salt thereof, each as described herein, in which:
(A) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group and a heteroaryl group; R 2 is a C 1 -C 6 alkyl group; R 3 and R 4 are independently a hydrogen atom or a C 1 -C 6 alkyl being unsubstituted or substituted with 1 to 3 substituents independently selected from the group consisting of a deuterium, a hydroxy group and a C 1 -C 6 alkoxy group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form a 4 to 6 membered heterocyclic group being unsubstituted or substituted with 1 to 2 substituent selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; A is an aryl group being unsubstituted or substituted with 1 to 5 substituents independently selected from the group consisting of a halogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, —NR 5 SO 2 R 6 and —CONR 7 R 8 ; R 5 , R 7 and R 8 are independently a hydrogen atom or a C 1 -C 6 alkyl group; and R 6 is a C 1 -C 6 alkyl group; and E is an oxygen atom; (B) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; R 2 is a C 1 -C 6 alkyl group; R 3 and R 4 are independently a hydrogen atom, a C 1 -C 3 alkyl group being unsubstituted or substituted with a hydroxy group or —CD 3 ; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; A is an aryl group being unsubstituted or substituted with 1 to 5 substituents independently selected from the group consisting of a halogen atom, a C 1 -C 6 alkyl group, a hydroxy-C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy-substituted C 1 -C 6 alkyl group, —NR 5 SO 2 R 6 and —CONR 7 R 8 ; R 5 , R 7 and R 8 are independently a hydrogen atom or a C 1 -C 6 alkyl group; and R 6 is a C 1 -C 6 alkyl group; and E is an oxygen atom; (C) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; R 2 is a C 1 -C 6 alkyl group; R 3 and R 4 are independently a hydrogen atom, a C 1 -C 3 alkyl group being unsubstituted or substituted with a hydroxy group or —CD 3 ; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; A is an aryl group being unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group and a hydroxy-C 1 -C 6 alkyl group; (D) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; R 2 is a methyl group; R 3 and R 4 are independently a hydrogen atom, a methyl group, —CD 3 or 2-hydroxyethyl group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group, a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; A is an aryl group being unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group and a hydroxy-C 1 -C 6 alkyl group; (E) R 1 is a C 1 -C 6 alkyl group being substituted with 1 to 2 substituents independently selected from the group consisting of a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; R 2 is a methyl group; R 3 and R 4 are independently a hydrogen atom, a methyl group, —CD 3 or 2-hydroxyethyl group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form a piperazinyl or morpholino group being unsubstituted or substituted with 1 to 2 substituents selected from the group consisting of a hydroxy group, an oxo group and a hydroxy-C 1 -C 3 alkyl group; a C 1 -C 6 alkyl group, a C 1 -C 6 acyl group and a hydroxy-C 1 -C 6 alkyl group; A is an aryl group being unsubstituted or substituted with 1 to 5 substituents selected from the group consisting of hydrogen atom, a halogen atom, a C 1 -C 6 alkyl group and a hydroxy-C 1 -C 6 alkyl group; (F) R 1 is a C 1 -C 6 alkyl group being substituted with a hydroxy group, a C 1 -C 6 alkoxy group or a heteroaryl group; R 2 is a C 1 -C 6 alkyl group; R 3 and R 4 are independently a hydrogen atom, a methyl group, —CD 3 or 2-hydroxyethyl group; or R 3 and R 4 taken together with the nitrogen atom to which they are attached form a morpholino group; A is an aryl group being unsubstituted or substituted with a halogen atom; and E is an oxygen atom.
[0079] The compounds of formula (I) containing one or more asymmetric carbon atoms can exist as two or more stereoisomers.
[0080] Included within the scope of the present invention are all stereoisomers and geometric isomers of the compounds of formula (I), including compounds exhibiting more than one type of isomerism, and mixtures of one or more thereof. Also included are acid addition salts wherein the counterion is optically active, for example, D-lactate or L-lysine, or racemate, DL-tartrate or DL-arginine.
[0081] One embodiment of the invention provides a compound selected from the group consisting of:
(−)-1-(2-methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide; (−)-8-(4-fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide 8-(4-fluorophenyl)-1-(3-hydroxypropyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide; 8-(4-fluorophenyl)-1-(isoxazol-3-ylmethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide; N,N-di[ 2 H 3 ]methyl-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide; 8-(4-fluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[8,7-d]imidazole-5-carboxamide; (8-(4-fluorophenyl)-1-(2-methoxyethyl)-2-methyl-1,6,7,8-tetrahydrochromeno[8,7-d]imidazol-5-yl)(morpholino)methanone
or a pharmaceutically acceptable salt thereof.
[0089] Pharmaceutically acceptable salts of a compound of formula (I) include the acid addition salts (including disalts) thereof.
[0090] Suitable acid addition salts are formed from acids which form non-toxic salts. Examples include the acetate, adipate, aspartate, benzoate, besylate, bicarbonate/carbonate, bisulphate/sulphate, borate, camsylate, citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate, gluconate, glucuronate, hexafluorophosphate, hibenzate, hydrochloride/chloride, hydrobromide/bromide, hydroiodide/iodide, isethionate, lactate, malate, maleate, malonate, mesylate, methylsulphate, naphthylate, 2-napsylate, nicotinate, nitrate, orotate, oxalate, palmitate, pamoate, phosphate/hydrogen phosphate/dihydrogen phosphate, pyroglutamate, saccharate, stearate, succinate, tannate, tartrate, tosylate, trifluoroacetate and xinofoate salts.
[0091] For a review on suitable salts, see “Handbook of Pharmaceutical Salts: Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH, Weinheim, Germany, 2002). A pharmaceutically acceptable salt of a compound of formula (I) may be readily prepared by mixing together solutions of the compound of formula (I) and the desired acid or base, as appropriate. The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent. The degree of ionization in the salt may vary from completely ionized to almost non-ionized.
[0092] Pharmaceutically acceptable salts of the compounds of the invention include both unsolvated and solvated forms. The term “solvate” is used herein to describe a molecular complex comprising a compound of the invention and one or more pharmaceutically acceptable solvent molecules, for example, ethanol. The term ‘hydrate’ is employed when said solvent is water.
[0093] Pharmaceutically acceptable solvates in accordance with the invention include hydrates and solvates wherein the solvent of crystallization may be isotopically substituted, e.g. D 2 O, d 6 -acetone, d 6 -DMSO.
[0094] Included within the scope of the invention are complexes such as clathrates, drug-host inclusion complexes wherein, in contrast to the aforementioned solvates, the drug and host are present in stoichiometric or non-stoichiometric amounts. Also included are complexes of the drug containing two or more organic and/or inorganic components which may be in stoichiometric or non-stoichiometric amounts. The resulting complexes may be ionized, partially ionized, or non-ionized. For a review of such complexes, see J Pharm Sci, 64 (8), 1269-1288 by Haleblian (August 1975).
[0095] The compounds of formula (I) may exist in one or more crystalline forms. These polymorphs, including mixtures thereof are also included within the scope of the present invention.
[0096] The compounds of formula (I) containing one or more asymmetric carbon atoms can exist as two or more stereoisomers.
[0097] Included within the scope of the present invention are all stereoisomers of the compounds of formula (I), including compounds exhibiting more than one type of isomerism, and mixtures of one or more thereof.
[0098] The present invention includes all pharmaceutically acceptable isotopically-labeled compounds of formula (I) wherein one or more atoms are replaced by atoms having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number usually found in nature.
[0099] Examples of isotopes suitable for inclusion in the compounds of the invention include isotopes of hydrogen, such as 2 H and 3 H, carbon, such as 11 C, 13 C and 14 C, chlorine, such as 36 Cl, fluorine, such as 18 F, iodine, such as 123 I and 125 I, nitrogen, such as 13 N and 15 N, oxygen, such as 15 O, 17 O and 18 O, phosphorus, such as 32 P, and sulphur, such as 35 S.
[0100] Certain isotopically-labeled compounds of formula (I), for example, those incorporating a radioactive isotope, are useful in drug and/or substrate tissue distribution studies. The radioactive isotopes tritium, i.e. 3 H, and carbon-14, i.e. 14 C, are particularly useful for this purpose in view of their ease of incorporation and ready means of detection.
[0101] Substitution with heavier isotopes such as deuterium, i.e. 2 H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements, and hence may be preferred in some circumstances.
[0102] Substitution with positron emitting isotopes, such as 11 C, 18 F, 15 O and 13 N, can be useful in Positron Emission Tomography (PET) studies for examining substrate receptor occupancy.
[0103] Isotopically-labeled compounds of formula (I) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described in the accompanying examples and preparations using an appropriate isotopically-labeled reagents in place of the non-labeled reagent previously employed.
[0104] All of the compounds of the formula (I) can be prepared by the procedures described in the general methods presented below or by the specific methods described in the examples section and the preparations section, or by routine modifications thereof. The present invention also encompasses any one or more of these processes for preparing the compounds of formula (I), in addition to any novel intermediates used therein.
General Synthesis
[0105] The compounds of the present invention may be prepared by a variety of processes well known for the preparation of compounds of this type, for example as shown in the following Method A and B.
[0106] Unless otherwise indicated, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , A and E in the following methods are as defined above. All starting materials in the following general syntheses may be commercially available or obtained by conventional methods known to those skilled in the art, such as WO 2004054984 and the disclosures of which are incorporated herein by references.
Method A
[0107] This illustrates the preparation of compounds of formula (Ia) wherein E is an oxygen atom.
[0000]
[0108] In Reaction Scheme A, R 1 , R 2 , R 3 , R 4 and A are each as defined above; Hal is a halogen atom, preferably a bromine atom; Lv is a leaving group; R 1a is R 1 as defined above or R 1 wherein hydroxy group is protected by a hydroxy-protecting group; R 2a is R 2 as defined above or R 2 wherein hydroxy group is protected by a hydroxy-protecting group; R 3a is R 3 as defined above or R 3 wherein hydroxy group is protected by a hydroxy-protecting group; R 4a is R 4 as defined above or R 4 wherein hydroxy group is protected by a hydroxy-protecting group; A a is A as defined above or A wherein hydroxy group is protected by a hydroxy-protecting group, Prot is hydroxy-protecting group; and the same shall apply hereinafter. The term “leaving group”, as used herein, signifies a group capable of being substituted by nucleophilic groups, such as a hydroxy group or amines and examples of such leaving groups include a halogen atom, a alkylsulfonyloxy group, a halogenoalkylsulfonyloxy group and a phenylsulfonyloxy group. Of these, a bromine atom, a chlorine atom, a methylsulfonyloxy group, a trifluoromethylsulfonyloxy group and a 4-methylphenylsulfonyloxy group are preferred.
[0109] The term “hydroxy-protecting groups”, as used herein, signifies a protecting group capable of being cleaved by various means to yield a hydroxy group, such as hydrogenolysis, hydrolysis, electrolysis or photolysis, and such hydroxy-protecting groups are described in Protective Groups in Organic Synthesis edited by T. W. Greene et al. (John Wiley & Sons, 1999). Such as for example, C 1 -C 6 alkoxycarbonyl, C 1 -C 6 alkylcarbonyl, tri-C 1 -C 6 alkylsilyl or tri-C 1 -C 8 alkylarylsilyl groups, and C 1 -C 6 alkoxy-C 1 -C 6 alkyl groups. Suitable hydroxy-protecting groups include acetyl and tert-butyldimethylsilyl.
(Step A1)
[0110] In this step, the compound (IV) is prepared by amide formation of the amino group of the compound of formula (II), which is commercially available or may be prepared by the methods described in WO 2004054984, with acid anhydride (III).
[0111] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; carboxylic acids, such as acetic acid; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; Of these solvents, acetic acid is preferred.
[0112] The reaction may be carried out in the presence of an acid. There is likewise no particular restriction on the nature of the acids used, and any acid commonly used in reactions of this type may equally be used here. Examples of such acids include: acids, such as hydrochloric acid, sulfuric acid or hydrobromic acid; sulfonic acids, such as methanesulfonic acid or toluenesulfonic acid. Of these, sulfuric acid is preferred.
[0113] The reaction may be carried out in the presence or absence of a base. There is likewise no particular restriction on the nature of the bases used, and any base commonly used in reactions of this type may equally be used here. Examples of such bases include: amines, such as N-methylmorpholine, triethylamine, tripropylamine, tributylamine, diisopropylethylamine, N-methylpiperidine, pyridine, 4-pyrrolidinopyridine, picoline, 4-(N,N-dimethylamino)pyridine, 2,6-di(tert-butyl)-4-methylpyridine, quinoline, N,N-dimethylaniline, N,N-diethylaniline, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Of these, the reaction in the absence of base is preferred.
[0114] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 5 minutes to about 24 hours will usually suffice.
(Step A2)
[0115] In this step, the compound of formula (VI) is prepared by the nucleophilic substitution of the compound of formula (IV) with the compound of formula (V).
[0116] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitriles, such as acetonitrile and benzonitrile; and sulfoxides, such as dimethyl sulfoxide and sulfolane. Of these solvents, N,N-dimethylformamide is preferred.
[0117] The reaction is carried out in the presence of a base. There is likewise no particular restriction on the nature of the bases used, and any base commonly used in reactions of this type may equally be used here. Examples of such bases include: alkali metal hydrides, such as lithium hydride, sodium hydride and potassium hydride; and alkali metal amides, such as lithium amide, sodium amide, potassium amide, lithium diisopropyl amide, potassium diisopropyl amide, sodium diisopropyl amide, lithium bis(trimethylsilyl)amide and potassium bis(trimethylsilyl)amide. Of these, sodium hydride is preferred.
[0118] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about −20° C. to about 80° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 30 minutes to about 24 hours, will usually suffice.
(Step A3)
[0119] In this step, the compound of formula (VII) is prepared by reduction and cyclization of the compound of formula (VI).
[0120] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; carboxylic acids, such as acetic acid; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; alcohols, such as methanol, ethanol, propanol, 2-propanol and butanol; nitriles, such as acetonitrile and benzonitrile; Of these solvents, acetic acid is preferred.
[0121] The reaction is carried out in the presence of a reducing agent. There is likewise no particular restriction on the nature of the reducing agents used, and any reducing agent commonly used in reactions of this type may equally be used here. Examples of such reducing agents include: a combination of metals, such as zinc and iron, and acids, such as hydrochloric acid, acetic acid and acetic acid-ammonium chloride complex; a combination of a hydrogen supplier, such as hydrogen gas and ammonium formate, and a catalyst, such as palladium-carbon, platinum and Raney nickel; Of these, the combination of iron and acetic acid or a combination of hydrogen gas and palladium carbon is preferred.
[0122] The reaction may be carried out in the presence of an acid. There is likewise no particular restriction on the nature of the acids used, and any acid commonly used in reactions of this type may equally be used here. Examples of such acids include: acids, such as hydrochloric acid, sulfuric acid or hydrobromic acid; carboxylic acids, such as acetic acid; sulfonic acids, such as methanesulfonic acid or toluenesulfonic acid. Of these, acetic acid is preferred.
[0123] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction temperature of from about 0° C. to about 120° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 30 minutes to about 24 hours will usually suffice.
(Step A4)
[0124] In this step, the compound of formula (VIII) is prepared by substitution of the halogen atom of the compound of formula (VII) with metal cyanide (A4a) followed by hydrolysis (A4b).
(A4a) Substitution of Halogen Atom
[0125] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: aliphatic hydrocarbons, such as halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide, 1-methylpyrrolidin-2-one and hexamethylphosphoric triamide; Of these solvents, N,N-dimethylformamide is preferred.
[0126] The reaction is carried out in the presence of a metal cyanide reagent. There is no particular restriction on the nature of the metal cyanide reagent to be employed, and any metal cyanide reagent commonly used in reactions of this type may equally be used here. Examples of such metal cyanide reagents include: zinc(II) cyanide, copper(I) cyanide, potassium cyanide and sodium cyanide; Of these, zinc(II) cyanide is preferred.
[0127] The reaction is carried out in the presence or absence of a palladium catalyst. There is no particular restriction on the nature of the palladium catalyst to be employed, and any palladium catalyst commonly used in reactions of this type may equally be used here. Examples of such palladium catalysts include: a palladium metal, palladium chloride, palladium (II) acetate, tris(dibenzylideneacetone)dipalladiumchloroform, allyl palladium chloride, [1,2-bis(diphenylphosphino)ethane]palladium dichloride, bis(tri-o-tolylphosphine)palladium dichloride, bis(triphenylphosphine)palladium dichloride, tetrakis(triphenylphosphine)palladium, dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium, or a catalyst produced in solution by adding a ligand into the reaction solution of these. The ligand added into the reaction solution may be a phosphoric ligand such as triphenylphosphine, 1,1′-bis(diphenylphosphino)ferrocene, bis(2-diphenylphosphinophenyl)ether, 2,2′-bis(diphenylphosphino)-1,1′-binaphthol, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, tri-o-tolylphosphine, 2-diphenylphosphino-2′-methoxy-1,1′-binaphthyl or 2,2-bis(diphenylphosphino)-1,1′-binaphthyl. Of these, tetrakis(triphenylphosphine)palladium is preferred.
[0128] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 50° C. to about 150° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 30 minutes to about 24 hours will usually suffice.
[0129] In this reaction, microwave can be employed to accelerate the reaction. In the case of employing microwave in sealed tube, the reaction at a temperature may be from about 50° C. to about 180° C. and the reaction time from about 5 minutes to about 12 hours will usually suffice.
(A4b) Hydrolysis
[0130] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; alcohols, such as methanol, ethanol, propanol, 2-propanol, butanol and ethylene glycol; sulfoxides, such as dimethyl sulfoxide and sulfolane; water; or mixed solvents thereof. Of these solvents, methanol, ethanol, tetrahydrofuran or ethylene glycol is preferred.
[0131] The reaction may be carried out in the presence of a base. There is likewise no particular restriction on the nature of the bases used, and any base commonly used in reactions of this type may equally be used here. Examples of such bases include: alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide and potassium hydroxide; alkali metal carbonates, such as lithium carbonate, sodium carbonate and potassium carbonate. Of these, potassium hydroxide, lithium hydroxide or sodium hydroxide is preferred.
[0132] The reaction may be carried out in the presence of an acid. There is likewise no particular restriction on the nature of the acids used, and any acid commonly used in reactions of this type may equally be used here. Examples of such acids include: carboxylic acids, such as acetic acid or propionic acid; acids, such as hydrochloric acid, sulfuric acid or hydrobromic acid. Of these, hydrochloric acid is preferred.
[0133] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 150° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 60 minutes to about 24 hours, will usually, suffice.
[0134] In this reaction, microwave can be employed to accelerate the reaction. In the case of employing microwave in sealed tube, the reaction at a temperature may be from about 50° C. to about 180° C. and the reaction time from about 5 minutes to about 12 hours will usually suffice.
(Step A5)
[0135] In this step, the compound (X) is prepared by amidation of the compound of formula (VIII) with the compound of formula (IX), which is commercially available or described in J. Org. Chem., 5935 (1990) and Canadian Journal of Chemistry, 2028 (1993).
[0136] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitriles, such as acetonitrile and benzonitrile; sulfoxides, such as dimethyl sulfoxide and sulfolane; or mixed solvents thereof. Of these, N,N-dimethylformamide is preferred.
[0137] The reaction is carried out in the presence of a base. There is likewise no particular restriction on the nature of the bases used, and any base commonly used in reactions of this type may equally be used here. Examples of such bases include: amines, such as N-methylmorpholine, triethylamine, tripropylamine, tributylamine, diisopropylethylamine, dicyclohexylamine, N-methylpiperidine, pyridine, 4-pyrrolidinopyridine, picoline, 4-(N,N-dimethylamino)pyridine, 2,6-di(tert-butyl)-4-methylpyridine, quinoline, N,N-dimethylaniline, N,N-diethylaniline, DBN, DABCO, and DBU. Of these, triethylamine or diisopropylethylamine is preferred.
[0138] The reaction is carried out in the presence of a condensing agent. There is likewise no particular restriction on the nature of the condensing agents used, and any condensing agent commonly used in reactions of this type may equally be used here. Examples of such condensing agents include: 2-halo-1-lower alkyl pyridinium salts, such as 2-chloro-1-methylpyridinium iodide and 2-bromo-1-ethylpyridinium tetrafluoroborate (BEP); diarylphosphoryl azides, such as diphenylphosphoryl azide (DPPA); chloroformates, such as ethyl chloroformate and isobutyl chloroformate; phosphorocyanidates, such as diethyl phosphorocyanidate (DEPC); imidazole derivatives, such as N,N′-carbonyldiimidazole (CDI); carbodiimide derivatives, such as N,N′-dicyclohexylcarbodiimide (DCC) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI); iminium salts, such as 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU) and tetramethyl fluoroformamidinium hexafluorophosphate (TFFH); and phosphonium salts, such as benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP) and bromo-tris-pyrrolidino-phosphonium hexafluorophosphate (PyBrop). Of these, EDCI or HBTU is preferred.
[0139] Reagents, such as 4-(N,N-dimethylamino)pyridine (DMAP), and 1-hydroxybenztriazole (HOBt), may be employed for this step. Of these, HOBt is preferred.
[0140] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 80° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 30 minutes to about 48 hours, will usually suffice.
[0141] Following this reaction, Prot 1 may be deprotected as follows.
(Deprotection of Prot)
[0142] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; alcohols, such as methanol, ethanol, propanol, 2-propanol and butanol; carboxylic acid, such as acetic acid or formic acid; Of these solvents, methanol is preferred.
[0143] The reaction is carried out in the presence of a palladium catalyst under the hydrogen gas. There is no particular restriction on the nature of the palladium catalyst to be employed, and any palladium catalyst commonly used in reactions of this type may equally be used here. Examples of such palladium catalysts include: palladium metal, palladium-carbon, palladium hydroxide, Of these, palladium-carbon or palladium hydroxide is preferred.
[0144] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
(Step A6)
[0145] In this step, the compound (XII) is prepared by Mannich reaction of the compound of formula (X) with Eshenmoser's salt (N,N-dimethylmethyleneiminium iodide) (A6a), followed by the coupling reaction with the compound of formula (XI)(A6b). The compound of formula (XI) is commercially available or may be prepared by the methods described in J. Am. Chem. Soc., 1994, 116, 5985-5986.
(A6a) Mannich Reaction
[0146] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitrites, such as acetonitrile; sulfoxides, such as dimethyl sulfoxide and sulfolane. Of these solvents, N,N-dimethylformamide or dichloromethane is preferred.
[0147] The reaction is carried out in the presence or absence of a base. There is likewise no particular restriction on the nature of the bases used, and any base commonly used in reactions of this type may equally be used here. Examples of such bases include: alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide and potassium hydroxide; alkali metal carbonates, such as lithium carbonate, sodium carbonate and potassium carbonate; alkali metal hydrogencarbonates, such as lithium hydrogencarbonate, sodium hydrogencarbonate and potassium hydrogencarbonate. Of these, potassium carbonate is preferred.
[0148] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about −20° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
[0000] (A6b) The Coupling Reaction with the Compound of Formula (XI)
[0149] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitriles, such as acetonitrile and benzonitrile; sulfoxides, such as dimethyl sulfoxide and sulfolane; ketones, such as acetone and diethylketone. Of these solvents, toluene is preferred.
[0150] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical, to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 150° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
(Step A7)
[0151] In this step, the compound (Ia) is prepared by reduction of the compound of formula (XII) (A7a), followed by the ring formation reaction (A7b).
(A7a) Reduction
[0152] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; sulfoxides, such as dimethyl sulfoxide and sulfolane; alcohols, such as methanol, ethanol, propanol, 2-propanol and butanol; or mixed solvents thereof. Of these, methanol or tetrahydrofuran is preferred.
[0153] The reaction is carried out in the presence of a reducing agent. There is likewise no particular restriction on the nature of the reducing agents used, and any reducing agent commonly used in reactions of this type may equally be used here. Examples of such reducing agents include: metal borohydrides, such as sodium borohydride, lithium borohydride and sodium cyanoborohydride; hydride compounds, such as lithium aluminum hydride and diisobutyl aluminum hydride; and borane reagents, such as boran-tetrahydrofuran complex, boran-dimethyl sulfide complex (BMS) and 9-borabicyclo[3.3.1]nonane (9-BBN). Of these, sodium borohydride is preferred.
[0154] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 80° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 8 hours will usually suffice.
(A7b) Ring Formation Reaction
[0155] The reaction may be effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents: include: aliphatic hydrocarbons, such as hexane, heptane and petroleum ether; halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitrites, such as acetonitrile and benzonitrile. Of these, tetrahydrofuran or toluene is preferred.
[0156] The reaction may be carried out in the presence of a condensing agent. There is likewise no particular restriction on the nature of the condensing agents used, and any condensing agent commonly used in reactions of this type may equally be used here. Examples of such condensing agents include: azodicarboxylic acid di-lower alkyl esters, such as diethyl azodicarboxylate (DEAD), diisopropyl azodicarboxylate (DIAD) and di-tert-butyl azodicarboxylate (DTAD); azodicarboxamides, such as N,N,N′,N′-tetraisopropylazodicarboxamide (TIPA), 1,1′-(azodicarbonyl)dipiperidine (ADDP) and N,N,N′,N′-tetramethylazodicarboxamide (TMAD); phosphoranes, such as (cyanomethylene)tributylphosphorane (CMBP) and (cyanomethylene)trimethylphosphorane (CMMP). Of these, DIAD or ADDP is preferred.
[0157] Phosphine reagents, such as triphenylphosphine, trimethylphosphine and tributylphosphine, may be employed for this step. Of these, triphenylphosphine or tributylphosphine is preferred.
[0158] Alternatively, the inorganic acids, such as sulphonic acid and phosphoric acid, and water may be used as solvent and condensing reagent. Of these, phosphoric acid water solution is preferred.
[0159] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
Introduction of the Hydroxy-Protecting Group
[0160] In the case where R 1 , R 2 , R 3 , R 4 or A has a hydroxy group, if necessary, the reaction may be accomplished by protecting the hydroxy group.
[0161] The introduction of the hydroxy-protecting group can be carried out at an appropriate step before the reaction affected by the hydroxy group.
[0162] This reaction is described in detail by T. W. Greene et al., Protective Groups in Organic Synthesis, 369-453, (1999), the disclosures of which are incorporated herein by reference. The following exemplifies a typical reaction involving the protecting group tert-butyldimethylsilyl.
[0163] For example, when the hydroxy-protecting group is a “tert-butyldimethylsilyl”, this step is conducted by reacting with a desired hydroxy-protecting group halide in an inert solvent in the presence of a base.
[0164] Examples of suitable solvents include: halogenated hydrocarbons, such as dichloromethane, chloroform, carbon tetrachloride and 1,2-dichloroethane; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; or mixed solvents thereof. Of these, tetrahydrofuran or N,N-dimethylformamide is preferred.
[0165] Examples of the hydroxy-protecting group halide usable in the above reaction include trimethylsilyl chloride, triethylsilyl chloride, tert-butyldimethylsilyl chloride, acetyl chloride are preferred.
[0166] Examples of the base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate, and organic amines such as triethylamine, tributylamine, N-methylmorpholine, pyridine, imidazole, 4-dimethylaminopyridine, picoline, lutidine, collidine, DBN and DBU. Out of these, triethylamine, imidazole, or pyridine is preferred. Upon use of an organic amine in the liquid form, it also serves as a solvent when used in large excess.
[0167] The protection reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
Deprotecting Step
[0168] In the case where R 1a , R 2a , R 3a , R 4a or Aa has a protected hydroxy group, the deprotection reaction will follow to yield a hydroxy group. This reaction is described in detail by T. W. Greene et al., Protective Groups in Organic Synthesis, 369-453, (1999), the disclosures of which are incorporated herein by reference. The following exemplifies a typical reaction involving the protecting group tert-butyldimethylsilyl.
[0169] The deprotection of the hydroxyl groups is carried out with an acid, such as acetic acid, hydrogen fluoride, hydrogen fluoride-pyridine complex, or fluoride ion, such as tetrabutylammonium fluoride (TBAF).
[0170] The deprotection reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include, but are not limited to: alcohol, such as methanol, ethanol or mixed solvents thereof.
[0171] The deprotection reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C.: The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
Method B
[0172] This illustrates the preparation of compounds of formula (Ia) wherein E is NH.
[0000]
(Step B1)
[0173] In this step, the compound (XIV) is prepared by nucleophilic substitution of the compound of formula (XIII), which is commercially available or may be prepared by the methods described in WO2004087701, with the compound of formula (V). The reaction may be carried out under the same condition as described in Step A2 of Method A.
(Step B2)
[0174] In this step, the compound (XV) is prepared is prepared by reduction the compound of formula (XIV). The reaction may be carried out under the same condition as described in Step A3 of Method A.
(Step B3)
[0175] In this step, the compound (XVII) is prepared by imine formation of the compound of formula (XV) with the compound of formula (XVI) (B3a) followed by the reaction with vinylmagnesium bromide (B3b).
(B3a) Imine Formation
[0176] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and nitrobenzene; amides, such as formamide, N,N-dimethylformamide, N,N-dimethylacetamide and hexamethylphosphoric triamide; nitriles, such as acetonitrile and benzonitrile; sulfoxides, such as dimethyl sulfoxide and sulfolane; or mixed solvents thereof. Of these, toluene is preferred.
[0177] The reaction may be carried out in the presence of an acid. There is likewise no particular restriction on the nature of the acids used, and any acid commonly used in reactions of this type may equally be used here. Examples of such acids include: acids, such as hydrochloric acid, sulfuric acid or hydrobromic acid; sulfonic acids, such as methanesulfonic acid or toluenesulfonic acid; carboxylic acids, such as acetic acid. Of these, toluenesulfonic acid is preferred.
[0178] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 5 minutes to about 24 hours, will usually suffice.
[0000] (B3b) Reaction with Vinylmagnesium Bromide
[0179] The reaction may be effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: aliphatic hydrocarbons, such as hexane, heptane and petroleum ether; ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene and toluene. Of these, tetrahydrofuran is preferred.
[0180] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about −78° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
(Step B4)
[0181] In this step, the compound (XVIII) is prepared by amino-Claisen rearrangement of the compound of formula (XVII) by heat (B4a), followed by the cyclization (B4b).
(B4a) Amino-Claisen Rearrangement
[0182] The reaction is normally and preferably effected in the presence of solvent. There is no particular restriction on the nature of the solvent to be employed, provided that it has no adverse effect on the reaction or the reagents involved and that it can dissolve reagents, at least to some extent. Examples of suitable solvents include: ethers, such as diethyl ether, diisopropyl ether, tetrahydrofuran and dioxane; aromatic hydrocarbons, such as benzene, toluene and xylene; or mixed solvents thereof. Of these, toluene is preferred.
[0183] The reaction may be carried out in the presence of an acid. There is likewise no particular restriction on the nature of the acids used, and any acid commonly used in reactions of this type may equally be used here. Examples of such acids include: acids, such as hydrochloric acid, sulfuric acid or hydrobromic acid; sulfonic acids, such as methanesulfonic acid or toluenesulfonic acid; Lewis acid, such as boron trifluoride-diethyl etherate or zinc chloride. Of these, toluenesulfonic acid is preferred.
[0184] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 150° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 48 hours, will usually suffice.
(B4b) Cyclization
[0185] The reaction is normally and preferably effected in the presence the inorganic acids, such as sulphonic acid and phosphoric acid, and water. Both may be used as solvent and condensing reagent. Of these, phosphoric acid water solution is preferred.
[0186] The reaction can take place over a wide range of temperatures, and the precise reaction temperature is not critical to the invention. The preferred reaction temperature will depend upon such factors as the nature of the solvent, and the starting materials. However, in general, it is convenient to carry out the reaction at a temperature of from about 0° C. to about 100° C. The time required for the reaction may also vary widely, depending on many factors, notably the reaction temperature and the nature of the starting materials and solvent employed. However, provided that the reaction is effected under the preferred conditions outlined above, a period of from about 10 minutes to about 24 hours, will usually suffice.
(Step B5)
[0187] In this step, the compound of formula (Ib) is prepared by the conversion of the halogen atom into carboxyl group within the compound of formula (XVIII) followed by the amidation with the compound of formula (IX). The reaction may be carried out under the same condition as described in Step A4 and A5 of Method A.
[0188] The preparation/isolation of individual enantiomers can be prepared by conventional techniques, such as chiral synthesis from a suitable optically pure precursor or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high-pressure liquid chromatography (HPLC) and supercritical fluid chromatography (SFC).
[0189] Alternatively, a method of optical resolution of a racemate (or a racemic precursor) can be appropriately selected from conventional procedures, for example, preferential crystallization, or resolution of diastereomeric salts between a basic moiety of the compound of formula (I) and a suitable optically active acid such as tartaric acid.
[0190] The compounds of formula (I), and the intermediates in the above-mentioned preparation methods can be isolated and purified by conventional procedures, such as distillation, recrystallization or chromatographic purification.
[0191] Compounds of the invention intended for pharmaceutical use may be administered as crystalline or amorphous products. They may be obtained, for example, as solid plugs, powders, or films by methods such as precipitation, crystallization, freeze-drying, spray drying, or evaporative drying. Microwave or radio frequency drying may be used for this purpose.
[0192] They may be administered alone or in combination with one or more other compounds of the invention or in combination with one or more other drugs (or as any combination thereof). Generally, they will be administered as a pharmaceutical composition or formulation in association with one or more pharmaceutically acceptable carriers or excipients. The term “carrier” or “excipient” is used herein to describe any ingredient other than the compound(s) of the invention. The choice of carrier or excipient will to a large extent depend on factors such as the particular mode of administration, the effect of the excipient on solubility and stability, and the nature of the dosage form.
[0193] Pharmaceutical compositions suitable for the delivery of compounds of the present invention and methods for their preparation will be readily apparent to those skilled in the art. Such compositions and methods for their preparation may be found, for example, in ‘Remington's Pharmaceutical Sciences’, 19th Edition (Mack Publishing Company, 1995).
Oral Administration
[0194] The compounds of the invention may be administered orally. Oral administration may involve swallowing, so that the compound enters the gastrointestinal tract, or buccal or sublingual administration may be employed by which the compound enters the blood stream directly from the mouth.
[0195] Formulations suitable for oral administration include solid formulations such as, for example, tablets, capsules containing particulates, liquids, or powders, lozenges (including liquid-filled), chews, multi- and nano-particulates, gels, solid solution, liposome, films (including muco-adhesive), ovules, sprays and liquid formulations.
[0196] Liquid formulations include, for example, suspensions, solutions, syrups and elixirs. Such formulations may be employed as fillers in soft or hard capsules and typically comprise a carrier, for example, water, ethanol, polyethylene glycol, propylene glycol, methylcellulose, or a suitable oil, and one or more emulsifying agents and/or suspending agents. Liquid formulations may also be prepared by the reconstitution of a solid, for example, from a sachet.
[0197] The compounds of the invention may also be used in fast-dissolving, fast-disintegrating dosage forms such as those described in Expert Opinion in Therapeutic Patents, 11 (6), 981-986 by Liang and Chen (2001).
[0198] For tablet dosage forms, depending on dose, the drug may make up from about 1 wt % to about 80 wt % of the dosage form, more typically from about 5 wt % to about 60 wt % of the dosage form. In addition to the drug, tablets generally contain a disintegrant. Examples of disintegrants include sodium starch glycolate, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, croscarmellose sodium, crospovidone, polyvinylpyrrolidone, methyl cellulose, microcrystalline cellulose, lower alkyl-substituted hydroxypropyl cellulose, starch, pregelatinised starch and sodium alginate. Generally, the disintegrant will comprise from about 1 wt % to about 25 wt %, preferably from about 5 wt % to about 20 wt % of the dosage form.
[0199] Binders are generally used to impart cohesive qualities to a tablet formulation. Suitable binders include microcrystalline cellulose, gelatin, sugars, polyethylene glycol, natural and synthetic gums, polyvinylpyrrolidone, pregelatinised starch, hydroxypropyl cellulose and hydroxypropyl methylcellulose. Tablets may also contain diluents, such as lactose (monohydrate, spray-dried monohydrate, anhydrous and the like), mannitol, xylitol, dextrose, sucrose, sorbitol, microcrystalline cellulose, starch and dibasic calcium phosphate dihydrate.
[0200] Tablets may also optionally comprise surface-active agents, such as sodium lauryl sulfate and polysorbate 80, and glidants such as silicon dioxide and talc. When present, surface active agents may comprise from about 0.2 wt % to about 5 wt % of the tablet, and glidants may comprise from about 0.2 wt % to about 1 wt % of the tablet.
[0201] Tablets also generally contain lubricants such as magnesium stearate, calcium stearate, zinc stearate, sodium stearyl fumarate, and mixtures of magnesium stearate with sodium lauryl sulphate. Lubricants generally comprise from about 0.25 wt % to about 10 wt %, preferably from about 0.5 wt % to about 3 wt % of the tablet.
[0202] Other possible ingredients include anti-oxidants, colourants, flavouring agents, preservatives and taste-masking agents.
[0203] Exemplary tablets contain up to about 80% drug, from about 10 wt % to about 90 wt % binder, from about 0 wt % to about 85 wt % diluent, from about 2 wt % to about 10 wt % disintegrant, and from about 0.25 wt % to about 10 wt % lubricant.
[0204] Tablet blends may be compressed directly or by roller to form tablets. Tablet blends or portions of blends may alternatively be wet-, dry-, or melt-granulated, melt congealed, or extruded before tabletting. The final formulation may comprise one or more layers and may be coated or uncoated; it may even be encapsulated.
[0205] The formulation of tablets is discussed in “ Pharmaceutical Dosage Forms: Tablets, Vol. 1”, by H. Lieberman and L. Lachman, Marcel Dekker, N.Y., N.Y., 1980 (ISBN 0-8247-6918-X).
[0206] Solid formulations for oral administration may be formulated to be immediate and/or modified release. Modified release formulations include delayed-, sustained-, pulsed-, controlled-, targeted and programmed release.
[0207] Suitable modified release formulations for the purposes of the invention are described in U.S. Pat. No. 6,106,864. Details of other suitable release technologies such as high energy dispersions and osmotic and coated particles are to be found in Verma et al, Pharmaceutical Technology On - line, 25(2), 1-14 (2001). The use of chewing gum to achieve controlled release is described in WO00/35298.
Parenteral Administration
[0208] The compounds of the invention may also be administered directly into the blood stream, into muscle, or into an internal organ. Suitable means for parenteral administration include intravenous, intraarterial, intraperitoneal, intrathecal, intraventricular, intraurethral, intrasternal, intracranial, intramuscular and subcutaneous. Suitable devices for parenteral administration include needle (including microneedle) injectors, needle-free injectors and infusion techniques.
[0209] Parenteral formulations are typically aqueous solutions which may contain excipients such as salts, carbohydrates and buffering agents (preferably to a pH of from about 3 to about 9), but, for some applications, they may be more suitably formulated as a sterile non-aqueous solution or as a dried form to be used in conjunction with a suitable vehicle such as sterile, pyrogen-free water.
[0210] The preparation of parenteral formulations under sterile conditions, for example, by lyophilisation, may readily be accomplished using standard pharmaceutical techniques well known to those skilled in the art.
[0211] The solubility of compounds of formula (I) used in the preparation of parenteral solutions may be increased by the use of appropriate formulation techniques, such as the incorporation of solubility-enhancing agents.
[0212] Formulations for parenteral administration may be formulated to be immediate and/or modified release. Modified release formulations include delayed-, sustained-, pulsed-, controlled-, targeted and programmed release. Thus compounds of the invention may be formulated as a solid, semi-solid, or thixotropic liquid for administration as an implanted depot providing modified release of the active compound. Examples of such formulations include drug-coated stents and PGLA microspheres.
Topical Administration
[0213] The compounds of the invention may also be administered topically to the skin or mucosa, that is, dermally or transdermally. Typical formulations for this purpose include gels, hydrogels, lotions, solutions, creams, ointments, dusting powders, dressings, foams, films, skin patches, wafers, implants, sponges, fibres, bandages and microemulsions. Liposomes may also be used. Typical carriers include alcohol, water, mineral oil, liquid petrolatum, white petrolatum, glycerin, polyethylene glycol and propylene glycol. Penetration enhancers may be incorporated—see, for example, J Pharm Sci, 88 (10), 955-958 by Finnin and Morgan (October 1999).
[0214] Other means of topical administration include delivery by electroporation, iontophoresis, phonophoresis, sonophoresis and microneedle or needle-free (e.g. Powderject™, Bioject™, etc.) injection.
[0215] Formulations for topical administration may be formulated to be immediate and/or modified release. Modified release formulations include delayed-, sustained-, pulsed-, controlled-, targeted and programmed release.
Inhaled/Intranasal Administration
[0216] The compounds of the invention can also be administered intranasally or by inhalation, typically in the form of a dry powder (either alone, as a mixture, for example, in a dry blend with lactose, or as a mixed component particle, for example, mixed with phospholipids, such as phosphatidylcholine) from a dry powder inhaler or as an aerosol spray from a pressurized container, pump, spray, atomiser (preferably an atomiser using electrohydrodynamics to produce a fine mist), or nebuliser, with or without the use of a suitable propellant, such as 1,1,1,2-tetrafluoroethane or 1,1,1,2,3,3,3-heptafluoropropane. For intranasal use, the powder may comprise a bioadhesive agent, for example, chitosan or cyclodextrin.
[0217] The pressurized container, pump, spray, atomizer, or nebuliser contains a solution or suspension of the compound(s) of the invention comprising, for example, ethanol, aqueous ethanol, or a suitable alternative agent for dispersing, solubilising, or extending release of the active, a propellant(s) as solvent and an optional surfactant, such as sorbitan trioleate, oleic acid, or an oligolactic acid.
[0218] Prior to use in a dry powder or suspension formulation, the drug product is micronised to a size suitable for delivery by inhalation (typically less than 5 microns). This may be achieved by any appropriate comminuting method, such as spiral jet milling, fluid bed jet milling, supercritical fluid processing to form nanoparticles, high pressure homogenization, or spray drying.
[0219] Capsules (made, for example, from gelatin or HPMC), blisters and cartridges for use in an inhaler or insufflator may be formulated to contain a powder mix of the compound of the invention, a suitable powder base such as lactose or starch and a performance modifier such as l-leucine, mannitol, or magnesium stearate. The lactose may be anhydrous or in the form of the monohydrate, preferably the latter. Other suitable excipients include dextran, glucose, maltose, sorbitol, xylitol, fructose, sucrose and trehalose.
[0220] A suitable solution formulation for use in an atomiser using electrohydrodynamics to produce a fine mist may contain from about 1 μg to about 20 mg of the compound of the invention per actuation and the actuation volume may vary from about 1 μl to about 100 μl. A typical formulation may comprise a compound of formula (I), propylene glycol, sterile water, ethanol and sodium chloride. Alternative solvents which may be used instead of propylene glycol include glycerol and polyethylene glycol.
[0221] Suitable flavors, such as menthol and levomenthol, or sweeteners, such as saccharin or saccharin sodium, may be added to those formulations of the invention intended for inhaled/intranasal administration. Formulations for inhaled/intranasal administration may be formulated to be immediate and/or modified release using, for example, poly(DL-lactic-coglycolic acid (PGLA). Modified release formulations include delayed-, sustained-, pulsed-, controlled-, targeted and programmed release.
[0222] In the case of dry powder inhalers and aerosols, the dosage unit is determined by means of a valve which delivers a metered amount. Units in accordance with the invention are typically arranged to administer a metered dose or “puff” containing from about 1 to about 100 μg of the compound of formula (I). The overall daily dose will typically be in the range about 50 μg to about 20 mg which may be administered in a single dose or, more usually, as divided doses throughout the day.
Rectal/Intravaginal Administration
[0223] The compounds of the invention may be administered rectally or vaginally, for example, in the form of a suppository, pessary, or enema. Cocoa butter is a traditional suppository base, but various alternatives may be used as appropriate.
[0224] Formulations for rectal/vaginal administration may be formulated to be immediate and/or modified release. Modified release formulations include delayed-, sustained-, pulsed-, controlled-, targeted and programmed release.
Other Technologies
[0225] The compounds of the invention may be combined with soluble macromolecular entities, such as cyclodextrin and suitable derivatives thereof or polyethylene glycol-containing polymers, in order to improve their solubility, dissolution rate, taste-masking, bioavailability and/or stability for use in any of the aforementioned modes of administration.
[0226] Drug-cyclodextrin complexes, for example, are found to be generally useful for most dosage forms and administration routes. Both inclusion and non-inclusion complexes may be used. As an alternative to direct complexation with the drug, the cyclodextrin may be used as an auxiliary additive, i.e. as a carrier, diluent, or solubiliser. Most commonly used for these purposes are alpha-, beta- and gamma-cyclodextrins, examples of which may be found in. WO91/11172, WO94/02518 and WO98/55148.
Kit-of-Parts
[0227] Inasmuch as it may be desirable to administer a combination of active compounds, for example, for the purpose of treating a particular disease or condition, it is within the scope of the present invention that two or more pharmaceutical compositions, at least one of which contains a compound in accordance with the invention, may conveniently be combined in the form of a kit suitable for coadministration of the compositions.
[0228] Thus the kit of the invention comprises two or more separate pharmaceutical compositions, at least one of which contains a compound of formula (I) in accordance with the invention, and means for separately retaining said compositions, such as a container, divided bottle, or divided foil packet. An example of such a kit is the familiar blister pack used for the packaging of tablets, capsules and the like.
[0229] The kit of the invention is particularly suitable for administering different dosage forms, for example, oral and parenteral, for administering the separate compositions at different dosage intervals, or for titrating the separate compositions against one another. To assist compliance, the kit typically comprises directions for administration and may be provided with a so-called memory aid.
Dosage
[0230] For administration to human patients, the total daily dose of the compounds of the invention is typically in the range of about 0.05 mg to about 500 mg depending, of course, on the mode of administration, preferred in the range of about 0.1 mg to about 400 mg and more preferred in the range of about 0.5 mg to about 300 mg. For example, oral administration may require a total daily dose of from about 1 mg to about 300 mg, while an intravenous dose may only require from about 0.5 mg to about 100 mg. The total daily dose may be administered in single or divided doses.
[0231] These dosages are based on an average human subject having a weight of about 65 kg to about 70 kg. The physician will readily be able to determine doses for subjects whose weight falls outside this range, such as infants and the elderly.
Combinations
[0232] As discussed above, a compound of the invention exhibits acid pump inhibitory activity. An acid pump antagonist of the present invention may be usefully combined with another pharmacologically active compound, or with two or more other pharmacologically active compounds, particularly in the treatment of gastroesophageal reflux disease. For example, an acid pump antagonist, particularly a compound of the formula (I), or a pharmaceutically acceptable salt thereof, as defined above, may be administered simultaneously, sequentially or separately in combination with one or more agents selected from:
(i) histamine H 2 receptor antagonists, e.g. ranitidine, lafutidine, nizatidine, cimetidine, famotidine and roxatidine; (ii) proton pump inhibitors, e.g. omeprazole, esomeprazole, pantoprazole, rabeprazole, tenatoprazole, ilaprazole and lansoprazole; (iii) oral antacid mixtures, e.g. Maalox®, Aludrox® and Gaviscon®; (iv) mucosal protective agents, e.g. polaprezinc, ecabet sodium, rebamipide, teprenone, cetraxate, sucralfate, chloropylline-copper and plaunotol; (v) anti-gastric agents, e.g. Anti-gastrin vaccine, itriglumide and Z-360; (vi) 5-HT 3 antagonists, e.g. dolasetron, palonosetron, alosetron, azasetron, ramosetron, mitrazapine, granisetron, tropisetron, E-3620, ondansetron and indisetron; (vii) 5-HT 4 agonists, e.g. tegaserod, mosapride, cinitapride and oxtriptane; (viii) laxatives, e.g. Trifyba®, Fybogel®, Konsyl®, Isogel®, Regulan®, Celevac® and Normacol®; (ix) GABA B agonists, e.g. baclofen and AZD-3355; (x) GABA B antagonists, e.g. GAS-360 and SGS-742; (xi) calcium channel blockers, e.g. aranidipine, lacidipine, falodipine, azelnidipine, clinidipine, lomerizine, diltiazem, gallopamil, efonidipine, nisoldipine, amlodipine, lercanidipine, bevantolol, nicardipine, isradipine, benidipine, verapamil, nitrendipine, barnidipine, propafenone, manidipine, bepridil, nifedipine, nilvadipine, nimodipine and fasudil; (xii) dopamine antagonists, e.g. metoclopramide, domperidone and levosulpiride; (xiii) Tachykinin (NK) antagonists, particularly NK-3, NK-2 and NK-1 antagonists, e.g. nepadutant, saredutant, talnetant, (αR,9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8,9,10,11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2,1-g][1,7]naphthridine-6-13-dione (TAK-637), 5-[[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy-3-(4-fluorophenyl)-4-morpholinyl]methyl]-1,2-dihydro-3H-1,2,4-triazol-3-one (MK-869), lanepitant, dapitant and 3-[[2-methoxy-5-(trifluoromethoxy)phenyl]methylamino]-2-phenyl-piperidine (2S,3S); (xiv) Helicobacter pylori infection agents, e.g. clarithromycin, roxithromycin, rokitamycin, flurithromycin, telithromycin, amoxicillin, ampicillin, temocillin, bacampicillin, aspoxicillin, sultamicillin, piperacillin, lenampicillin, tetracycline, metronidazole, bithmuth citrate and bithmuth subsalicylate; (xv) nitric oxide synthase inhibitors, e.g. GW-274150, tilarginine, P54, guanidioethyldisulfide and nitroflurbiprofen; (xvi) vanilloid receptor 1 antagonists, e.g. AMG-517 and GW-705498; (xvii) muscarinic receptor antagonists, e.g. trospium, solifenacin, tolterodine, tiotropium, cimetropium, oxitropium, ipratropium, tiquizium, dalifenacin and imidafenacin; (xviii) calmodulin antagonists, e.g. squalamine and DY-9760; (xix) potassium channel agonists, e.g. pinacidil, tilisolol, nicorandil, NS-8 and retigabine; (xx) beta-1 agonists, e.g. dobutamine, denopamine, xamoterol, denopamine, docarpamine and xamoterol; (xxi) beta-2 agonists, e.g. salbutamol; terbutaline, arformoterol, meluadrine, mabuterol, ritodrine, fenoterol, clenbuterol, formoterol, procaterol, tulobuterol, pirbuterol, bambuterol, tulobuterol, dopexamine and levosalbutamol; (xxii) beta agonists, e.g. isoproterenol and terbutaline; (xxiii) alpha 2 agonists, e.g. clonidine, medetomidine, lofexidine, moxonidine, tizanidine, guanfacine, guanabenz, talipexole and dexmedetomidine; (xxiv) endthelin A antagonists, e.g. bonsetan, atrasentan, ambrisentan, clazosentan, sitaxsentan, fandosentan and darusentan; (xxv) opioid μ agonists, e.g. morphine, fentanyl and loperamide; (xxvi) opioid μ antagonists, e.g. naloxone, buprenorphine and alvimopan; (xxvii) motilin agonists, e.g. erythromycin, mitemcinal, SLV-305 and atilmotin; (xxviii) ghrelin agonists, e.g. capromorelin and TZP-101; (xxix) AchE release stimulants, e.g. Z-338 and KW-5092; (xxx) CCK-B antagonists, e.g. itriglumide, YF-476 and S-0509; (xxxi) glucagon antagonists, e.g. N,N-2501 and A-770077; (xxxii) piperacillin, lenampicillin, tetracycline, metronidazole, bithmuth citrate and bithmuth subsalicylate; (xxxiii) Glucagon-like peptide-1 (GLP-1) antagonists, e.g. PNU-126814; (xxxiv) small conductance calcium-activated potassium channel 3 (SK-3) antagonists, e.g. apamin, dequalinium, atracurium, pancuronium and tubocurarine. (xxxv) mGluR5 antagonists, e.g. ADX-10059 and AFQ-056; (xxxvi) 5-HT3 agonists, e.g. pumosetrag (DDP733); (xxxvii) mGluR8 agonists, e.g. (S)-3,4-DCPG and mGluR8-A.
Method for Assessing Biological Activities:
[0270] The acid pump inhibitory activity and other biological activities of the compounds of this invention were determined by the following procedures. Symbols have their usual meanings: mL (milliliter(s)), μL (microliter(s)), Kg (kirogram(s)), g (gram(s)), mg (milligram(s)), μg (microgram(s)), pmol (pico molar(s)), mmol (milli molar(s)), M (molar mass (m 3 /mol)), mM (milli molar mass), μM (micro molar mass), quant. (quantitative yield), nm (nanometer(s)), min (minute(s)), Cat# (catalog number), mV (millivolt(s)), ms (millisecond(s)), i.p. (intraperitoneal).
[0000] Preparation of Gastric Vesicles from Fresh Porcine Stomachs
[0271] The porcine gastric vesicles for Porcine gastric H + /K + -ATPase inhibition assays were prepared from mucous membrane in fresh porcine stomachs by homogenization with a tight-fitted polytetrafluoroethylene (Teflone®) homogenizer in 0.25 M sucrose at 4° C. The crude pellet was removed with centrifugation at 20,000 g for 30 min. Then supernatant was centrifuged at 100,000 g for 30 min. The resulting pellet was re-suspended in 0.25 M sucrose, and then subjected to density gradient centrifugation at 132,000 g for 90 min. The gastric vesicles were collected from interface on 0.25 M sucrose layer containing 7% Ficoll™ PM400 (Amersham Biosciences). This procedure was performed in a cold room.
Ion-leaky Porcine Gastric H + /K + -ATPase Inhibition
[0272] Ion-leaky porcine gastric H + /K + -ATPase inhibition was measured according to the modified method described in Biochemical Pharmacology, 1988, 37, 2231-2236.
[0273] The isolated vesicles were lyophilized, and then kept in deep-freezer until use. For enzyme assay, lyophilized vesicles were reconstituted with 3 mM MgSO 4 containing 40 mM Bis-tris (pH 6.4 at 37° C.).
[0274] Enzyme reaction was performed incubating 5 mM KCl, 3 mM Na 2 ATP, 3 mM MgSO 4 and 1.0 μg of reconstituted vesicles for 30 minutes at 37° C. in a final 60 μl of reaction mixture (40 mM Bis-tris, pH 6.4) with or without the test compound. Enzyme reaction was stopped by adding 10% sodium dodecyl sulphate (SDS). Released inorganic phosphate from ATP was detected by incubation with mixture of 1 part of 35 mM ammonium molybdate tetrahydrate in 15 mM Zinc acetate hydrate and 4 parts of 10% ascorbic acid (pH 5.0), resulting in phosphomolybdate, which has optical density at 750 nm. All example compounds showed potent inhibitory activity.
[0275] The results of IC 50 values of the inhibitory activity for the compounds of following examples are shown in Table 1.
[0000]
TABLE 1
Example No.
IC 50 (μM)
1
0.098
2
0.52
3
0.068
4
0.19
5
0.088
6
0.23
7
0.038
8
0.34
9
0.35
10
0.10
11
0.21
12
0.090
13
0.34
14
0.27
15
0.20
16
0.074
17
1.0
All the tested compounds showed acid pump antagonistic activity.
Ion-Tight Porcine Gastric H + /K + -ATPase Inhibition
[0276] Ion-tight porcine gastric H + /K + -ATPase inhibition was measured according to the modified method described in Biochemical Pharmacology, 1988, 37, 2231-2236.
[0277] The isolated vesicles were kept in deep-freezer until use. For enzyme assay, vesicles were diluted with 3 mM MgSO 4 containing 5 mM Tris (pH 7.4 at 37° C.).
[0278] Enzyme reaction was performed incubating 150 mM KCl, 3 mM Na 2 ATP, 3 mM MgSO 4 , 15 μM valinomycin and 3.0 μg of vesicles for 30 minutes at 37° C. in a final 60 μl of reaction mixture (5 mM Tris, pH 7.4) with or without the test compound. Enzyme reaction was stopped by adding 10% SDS. Released inorganic phosphate from ATP was detected by incubating with mixture of 1 part of 35 mM ammonium molybdate tetrahydrate in 15 mM Zinc acetate hydrate and 4 parts of 10% ascorbic acid (pH 5.0), resulting in phosphomolybdate, which has optical density at 750 nm.
Canine Kidney Na + /K + -ATPase Inhibition
[0279] The powdered canine kidney Na + /K + -ATPase (Sigma) was reconstituted with 3 mM MgSO 4 containing 40 mM Tris (pH 7.4 at 37° C.). Enzyme reaction was performed incubating 100 mM NaCl, 2 mM KCl, 3 mM Na 2 ATP, 3 mM MgSO 4 and 12 μg of enzyme for 30 minutes at 37° C. in a final 60 μl of reaction mixture (40 mM Tris, pH 7.4) with or without the test compound. Enzyme reaction was stopped by adding 10% SDS. Released inorganic phosphate from ATP was detected by incubating with mixture of 1 part of 35 mM ammonium molybdate tetrahydrate in 15 mM Zinc acetate hydrate and 4 parts of 10% ascorbic acid (pH 5.0), resulting in phosphomolybdate, which has optical density at 750 nm.
Inhibition of Acid Secretion in the Gastric Lumen-Perfused Rat
[0280] Acid secretion in the gastric lumen-perfused rat was measured according to Watanabe et al. [Watanabe K et al., J. Physiol. (Paris) 2000; 94: 111-116].
[0000] Male Sprague-Dawley rats, 8 weeks old, deprived of food for 18 hours before the experiment with free access to water, were anesthetized with urethane (1.4 g/kg, i.p.) and tracheotomized. After a middle abdominal incision, a dual polyethylene cannula was inserted into the forestomach and the stomach was perfused with saline (37° C., pH 5.0) at a rate of 1 ml/min. The acid output in the perfusate was determined at 5 minutes interval by titration with 0.02 M NaOH to pH 5.0. After the determination of basal acid secretion for 30 min, the acid secretion was stimulated by a continuous intravenous infusion of pentagastrin (16 μg/kg/h). The test compounds were administered by an intravenous bolus injection or intraduodenal administration after the stimulated acid secretion reached a plateau phase. The acid secretion was monitored after the administration.
[0281] The activity was evaluated either inhibition of total acid secretion from 0 hours to 1.5 or 3.5 hours after administration or the maximum inhibition after administration.
Inhibition of Gastric Acid Secretion in the Heidenhain Pouch Dog
[0282] Male Beagle dogs weighing 7-15 kg with Heidenhain pouch [Heidenhain R: Arch Ges Physiol. 1879; 19: 148-167] were used. The animals were allowed to recover from surgery for at least three weeks before the experiments. The animals were kept at a 12 hour light-dark rhythm, housed singly. They received standard food once daily at 11:00 a.m. and tap water ad libitum, and were fasted overnight prior to the experiment, with free access to water. Gastric juice samples were collected throughout the experiment by gravity drainage every 15 min. Acidity in the gastric juice was measured by titration to the end point of pH 7.0. Acid secretion was stimulated by a continuous intravenous infusion of histamine (80 μg/kg/h). Oral or intravenous bolus administration of the test compounds was done 90 minutes after commencement of the histamine infusion. The acid secretion was monitored after the administration. The activity was evaluated by the maximum inhibition relative to the corresponding control value.
Human Dofetilide Binding
[0283] Human ether a-go-go related gene (HERG) transfected HEK293S cells were prepared and grown in-house. Cell paste of HEK-293 cells expressing the HERG product can be suspended in 10-fold volume of 50 mM Tris buffer adjusted at pH 7.5 at 25° C. with 2 M HCl containing 1 mM MgCl 2 , 10 mM KCl. The cells were homogenized using a Polytron homogenizer (at the maximum power for 20 seconds) and centrifuged at 48,000 g for 20 minutes at 4° C. The pellet was resuspended, homogenized and centrifuged once more in the same manner. The resultant supernatant was discarded and the final pellet was resuspended. (10-fold volume of 50 mM Tris buffer) and homogenized at the maximum power for 20 seconds. The membrane homogenate was aliquoted and stored at −80° C. until use. An aliquot was used for protein concentration determination using a Protein Assay Rapid Kit (wako) and Spectra max plate reader (Wallac). All the manipulation, stock solution and equipment were kept on ice at all times. For saturation assays, experiments were conducted in a total volume of 200 μl. Saturation was determined by incubating 36 μl of [ 3 H]-dofetilide, and 160 μl of membrane homogenates (20-30 μg protein per well) for 60 minutes at room temperature in the absence or presence of 10 μM dofetilide at final concentrations (4 μl) for total or nonspecific binding, respectively. All incubations were terminated by rapid vacuum filtration over PEI soaked glass fiber filter papers using Skatron cell harvester followed by two washes with 50 mM Tris buffer (pH 7.4 at 25° C.). Receptor-bound radioactivity was quantified by liquid scintillation counting using Packard LS counter.
[0284] For the competition assay, compounds were diluted in 96 well polypropylene plates as 4-point dilutions in semi-log format. All dilutions were performed in DMSO first and then transferred into 50 mM Tris buffer (pH 7.4 at 25° C.) containing 1 mM MgCl 2 , 10 mM KCl so that the final DMSO concentration became equal to 1%. Compounds were dispensed in triplicate in assay plates (4 μl). Total binding and nonspecific binding wells were set up in 6 wells as vehicle and 10 μM dofetilide at final concentration, respectively. The radioligand was prepared at 5.6× final concentration and this solution was added to each well (36 μl). The assay was initiated by addition of YSi poly-L-lysine SPA beads (50 μl, 1 mg/well) and membranes (110 μl, 20 μg/well). Incubation was continued for 60 minutes at room temperature. Plates were incubated for a further 3 hours at room temperature for beads to settle. Receptor-bound radioactivity was quantified by counting Wallac MicroBeta plate counter.
Half-Life in Human Liver Microsomes (HLM)
[0285] Test compounds (1 μM) were incubated with 1 mM MgCl 2 , 1 mM NADP+, 5 mM isocitric acid, 1 U/mL isocitric dehydrogenase and 0.8 mg/mL HLM in 100 mM potassium phosphate buffer (pH 7.4) at 37° C. on a number of 384-well plates. At several time points, a plate was removed from the incubator and the reaction was terminated with two incubation volumes of acetonitrile. The compound concentration in supernatant was measured by LC/MS/MS system. The intrinsic clearance value was calculated using following equations:
[0000]
Cl
int
(
ul
/
min
/
mg
protein
)
=
k
×
incubation
volume
Protein
concentration
[0000] Where, k=−slope of ln(concentration) vs. time (min-1)
hERG Patch Clamp Assay
[0286] To determine the potential of compounds to inhibit the hERG channel, the cloned counterpart of the rapidly inactivating delayed rectifier potassium current (IKr).
[0287] HEK293 cells stably expressing the hERG channel were used in whole-cell patch clamp electrophysiology studies at ambient temperature (26.5-28.5° C.). The methodology for stable transfection of this channel in HEK293 cells can be found elsewhere (Zhou et al 1998, Biophysical Journal, 74, pp 230-241). The solutions used for experimentation were standard extracellular solution of the following composition (mM); NaCl, 137; KCl, 4; CaCl 2 , 1.8; MgCl 2 , 1; Glucose, 10; HEPES, 10; pH 7.4±0.05 with NaOH/HCl; and standard intracellular solution of the following composition (mM); KCl, 130; MgCl 2 , 1; HEPES, 10; EGTA, 5; MgATP, 5; pH 7.2±0.05 with KOH. The voltage protocol applied was designed to activate the hERG channel and allow the measurement of drug block of the channel and is as follows. First the membrane potential was stepped from a holding potential of −80 mV to +30 mV for 1 s. This was followed by a descending voltage ramp at a rate of 0.5 mV/ms back to holding potential of −80 mV and the peak outward current observed during the repolarizing ramp was measured. This protocol was evoked repeatedly every 4 seconds (0.25 Hz). After establishing a stable baseline period in the presence of vehicle (0.1% v/v DMSO), four increasing concentrations of test compound were then bath-applied sequentially until the response reached steady-state or 10 minutes (whichever occurred first). 10 micromol/L dofetilide was used at the end of each experiment as an internal positive control and to define maximum block.
Bioavailability in Rat
[0288] Adult rats of the Sprague-Dawley strain were used. One to two days prior to the experiments all rats were prepared by cannulation of the right jugular vein under anesthesia. The cannula was exteriorized at the nape of the neck. Blood samples (0.2-0.3 mL) were drawn from the jugular vein at intervals up to 24 hours after intravenous or oral administrations of the test compound. The samples were frozen until analysis. Bioavailability was assessed by calculating the quotient between the area under plasma concentration curve (AUC) following oral administration or intravenous administration.
Bioavailability in Dog
[0289] Adult Beagle dogs were used. Blood samples (0.2-0.5 mL) were drawn from the cephalic vein at intervals up to 24 hours after intravenous or oral administrations of the test compound. The samples were frozen until analysis. Bioavailability was assessed by calculating the quotient between the area under plasma concentration curve (AUC) following oral administration or intravenous administration.
Plasma Protein Binding
[0290] Plasma protein binding of the test compound (1 μM) was measured by the method of equilibrium dialysis using 96-well plate type equipment. Spectra-Por®, regenerated cellulose membranes (molecular weight cut-off 12,000-14,000, 22 mm×120 mm) were soaked for over night in distilled water, then for 20 minutes in 30% ethanol, and finally for 15 minutes in dialysis buffer (Dulbecco's phosphate buffered saline, pH7.4). Frozen plasma of human, Sprague-Dawley rats, and Beagle dogs were used. The dialysis equipment was assembled and added 150 μL of compound-fortified plasma to one side of each well and 150 μL of dialysis buffer to the other side of each well. After 4 hours incubation at 37° C. for 150 r.p.m, aliquots of plasma and buffer were sampled. The compound in plasma and buffer were extracted with 300 μL of acetonitrile containing internal standard compounds for analysis. The concentration of the compound was determined with LC/MS/MS analysis.
[0291] The fraction of the compound unbound was calculated by the following equation:
[0000] fu= 1−{([plasma] eq −[buffer] eq )/([plasma] eq )}
[0000] wherein [plasma] eq and [buffer] eq are the concentrations of the compound in plasma and buffer, respectively.
EXAMPLES
[0292] The following examples are provided for the purpose of further illustration only and are not intended to be limitations on the disclosed invention. Unless stated on otherwise in the following examples, general experimental conditions are as follows: all operations were carried out at room or ambient temperature, that is, in the range of 18-25° C.; evaporation of solvent was carried out using a rotary evaporator under reduced pressure with a bath temperature of up to 60° C.; reactions were monitored by thin layer chromatography (TLC) and reaction times are given for illustration only; melting points (mp) given are uncorrected (polymorphism may result in different melting points); the structure and purity of all isolated compounds were assured by at least one of the following techniques: TLC (Merck silica gel 60 F 254 precoated TLC plates or Merck NH 2 gel (an amine coated silica gel) F 254s precoated TLC plates), mass spectrometry, nuclear magnetic resonance spectra (NMR), infrared absorption spectra (IR) or microanalysis. Yields are given for illustrative purposes only. Flash column chromatography was carried out using Biotage KP-SIL (40-63 μm), Biotage KP-NH (an amine coated silica gel) (40-75 μM), Fuji Silysia amino gel (30-50 μm) or Wako silica gel 300HG (40-60 μM). Microwave reactions were carried out using Personal Chemistry Emrys™ Optimizer or Biotage Initiator™. Preparative TLC was carried out using Merck silica gel 60 F 254 precoated TLC plates (0.5 or 1.0 mm thickness). All Mass data was obtained in Low-resolution mass spectral data (ESI) using ZMD™ or ZQ™ (Waters) and mass spectrometer. NMR data were determined at 270 MHz (JEOL JNM-LA 270 spectrometer) or 300 MHz (JEOL JNM-LA300 spectrometer) using deuterated chloroform (99.8%) or dimethylsulfoxide (99.9%) as solvent unless indicated otherwise, relative to tetramethylsilane (TMS) as internal standard in parts per million (ppm); conventional abbreviations used are: s=singlet, d=doublet, m=multiplet, dd=doublet of doublet, sep=septet, br.s=broad singlet, br.d=broad doublet, etc. IR spectra were measured by a Fourier transform infrared spectrophotometer (Shimazu FTIR-8300). Optical rotations were measured using a P-1020 Digital Polarimeter (JASCO Corporation).
Example 1
1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0293]
STEP 1: N-[2-(Benzyloxy)-4-bromo-6-nitrophenyl]acetamide
[0294] To a solution of 2-(benzyloxy)-4-bromo-6-nitroaniline (33.0 g, 102 mmol, WO 2004054984) and acetic anhydride (14.5 mL, 153 mmol) in acetic acid (90 mL) was added concentrated sulfuric acid (2 drops) at 70° C. The mixture was stirred at 70° C. for 20 minutes. After cooling to room temperature, water (800 mL) was added, and the formed precipitate was collected by filtration and washed with diisopropyl ether to afford the title compound as a brown solid (30.9 g, 83%).
[0295] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.69 (d, J=2.0 Hz, 1H), 7.56 (brs, 1H), 7.47-7.38 (m, 5H), 7.34 (d, J=2.0 Hz, 1H), 5.14 (s, 2H), 2.16 (s, 3H) ppm.
[0296] MS (ESI) m/z: 365 (M+H) + .
STEP 2: N-[2-(Benzyloxy)-4-bromo-6-nitrophenyl]-N-(2-methoxyethyl)acetamide
[0297] To a suspension of sodium hydride (60% dispersion in mineral oil, 1.78 g, 44.5 mmol) in N,N-dimethylformamide (100 mL) was added dropwise a solution of N-[2-(benzyloxy)-4-bromo-6-nitrophenyl]acetamide (13.5 g, 37.1 mmol, Step 1) in N,N-dimethylformamide at 0° C. over 10 minutes. After stirring at 0° C. for 20 minutes, 1-bromo-2-methoxyethane (7.21 g, 51.9 mmol) was added, and the mixture was stirred at 50° C. for 2 hours. After cooling to room temperature, the mixture was poured onto water, and the aqueous layer was extracted with ethyl acetate/toluene (3:1). The combined organic layer was dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (3:1) to afford the title compound as a gray solid (12.1 g, 77%).
[0298] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.70 (d, J=2.6 Hz, 1H), 7.45-7.32 (m, 6H), 5.22-5.10 (m, 2H), 4.23-4.13 (m, 1H), 3.51-3.34 (m, 2H), 3.24-3.13 (m, 1H), 3.09 (s, 3H), 1.89 (s, 3H) ppm. (Signals of other rotamers were also observed)
[0299] MS (ESI) m/z: 423 (M+H) + .
STEP 3: 7-(Benzyloxy)-5-bromo-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole
[0300] A mixture of N-[2-(benzyloxy)-4-bromo-6-nitrophenyl]-N-(2-methoxyethyl)acetamide (11.7 g, 27.7 mmol, Step 2) and iron powder (7.74 g, 139 mmol) in acetic acid (150 mL) was refluxed with stirring for 5 hours. After cooling to room temperature, the mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo. The residue was poured onto water, and the aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with brine, dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (gradient elution from 2:1 to 1:1) to afford the title compound as a pale green solid (9.74 g, 93%).
[0301] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.47-7.37 (m, 6H), 6.89 (d, J=1.3 Hz, 1H), 5.14 (s, 2H), 4.39 (t, J=5.3 Hz, 2H), 3.57 (t, J=5.3 Hz, 2H), 3.16 (s, 3H), 2.57 (s, 3H) ppm.
STEP 4: 7-(Benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carbonitrile
[0302] A mixture of 7-(benzyloxy)-5-bromo-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole (1.00 g, 2.66 mmol, Step 3), zinc cyanide (376 mg, 3.20 mmol), and tetrakis(triphenylphosphine)palladium (154 mg, 0.13 mmol) in N,N-dimethylformamide (15 mL) was stirred at 90° C. for 3 hours under nitrogen gas. After cooling to room temperature, the mixture was poured onto saturated potassium carbonate aqueous solution (100 mL), and the aqueous layer was extracted with ethyl acetate. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residual solid was washed with ethyl acetate/diisopropyl ether (1:2) to afford the title compound as a white solid (648 mg, 76%).
[0303] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.67 (br.s, 1H), 7.45-7.38 (m, 5H), 6.96 (br.s, 1H), 5.19 (s, 2H), 4.45 (t, J=5.3 Hz, 2H), 3.60 (t, J=4.6 Hz, 2H), 3.19 (s, 3H), 2.61 (s, 3H) ppm.
[0304] MS (ESI) m/z: 322 (M+H) + .
STEP 5: 7-(Benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylic acid
[0305] A solution of 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carbonitrile (549 mg, 1.71 mmol, Step 4) and potassium hydroxide (85%, 564 mg, 8.54 mmol) in ethylene glycol (10 mL) was stirred at 135° C. for 5 hours. After cooling to room temperature, 2 mol/L hydrochloric acid was added until pH of the solution became about 3. The formed precipitate was collected by filtration to afford the title compound as a gray solid (530 mg, 91%).
[0306] 1 H NMR (DMSO-d 6 , 270 MHz) δ: 7.77 (br.s, 1H), 7.56-7.49 (m, 2H), 7.47-7.33 (m, 4H), 5.30 (s, 2H), 4.47, (t, J=5.3 Hz, 2H), 3.60 (t, J=5.3 Hz, 2H), 3.17 (s, 3H), 2.52 (s, 3H) ppm. (COOH was not observed)
[0307] MS (ESI) m/z: 341 (M+H) + , 339 (M−H) − .
STEP 6: Methyl 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate
[0308] To a suspension of 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylic acid (10.0 g, 29.4 mmol, Step 5) in methanol was added dropwise thionyl chloride (8.57 mL, 118 mmol) at room temperature, and the mixture was refluxed with stirring for 2 hours. After cooling to room temperature, the solvent was evaporated in vacuo. The residue was poured onto saturated sodium hydrogencarbonate aqueous solution, and the aqueous layer was extracted with dichloromethane. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was suspended in diisopropyl ether (100 mL), and the precipitate was collected by filtration to afford the title compound as a gray solid (9.22 g, 85%).
[0309] 1 H NMR (CDCl 3 , 270 MHz) δ: 8.06 (s, 1H), 7.51 (s, 1H), 7.48-7.35 (m, 5H), 5.23 (s, 2H), 4.45 (t, J=5.3 Hz, 2H), 3.94 (s, 3H), 3.61 (t, J=5.3 Hz, 2H), 3.17 (s, 3H), 2.60 (s, 3H) ppm.
[0310] MS (ESI) m/z: 355 (M+H) + .
STEP 7: Methyl 7-hydroxy-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate
[0311] A mixture of methyl 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (9.21 g, 26.0 mmol, Step 6) and 10% palladium on carbon (500 mg) in methanol (150 mL) was stirred under hydrogen gas (4 atm) for 5 hours. The resulting mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo. The residue was suspended in diisopropyl ether (150 mL), and the precipitate was collected by filtration to afford the title compound as a gray solid (6.35 g, 92%).
[0312] 1 H NMR (CDCl 3 , 270 MHz) δ: 10.31 (br.s, 1H), 7.62 (s, 1H), 7.24 (s, 1H), 4.49 (t, J=4.6 Hz, 2H), 3.83 (s, 3H), 3.68 (t, J=5.3 Hz, 2H), 3.21 (s, 3H) ppm.
[0313] MS (ESI) m/z: 266 (M+H) + , 264 (M−H) − .
STEP 8: Methyl 6-[(dimethylamino)methyl]-7-hydroxy-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate
[0314] The title compound was prepared as a white solid in 42% yield from methyl 7-hydroxy-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (3.00 g, Step 7) by the same manner in Step 3 of Example 5.
[0315] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.72 (s, 1H), 4.54 (t, J=5.3 Hz, 2H), 4.24 (s, 2H), 3.88 (s, 3H), 3.76 (t, J=5.3 Hz, 2H), 3.27 (s, 3H), 2.59 (s, 3H), 2.38 (s, 6H) ppm. (OH was not observed)
[0316] MS (ESI) m/z: 322 (M+H) + , 320 (M−H) − .
STEP 9: Methyl 7-hydroxy-1-(2-methoxyethyl)-2-methyl-6-(3-oxo-3-phenylpropyl)-1H-benzimidazole-5-carboxylate
[0317] A mixture of methyl 6-[(dimethylamino)methyl]-7-hydroxy-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (2.04 g, 6.35 mmol, Step 8) and 1-(1-phenylvinyl)pyrrolidine (1.43 g, 8.25 mmol, J. Am. Chem. Soc., 1994, 116, 5985-5986.) in toluene (80 mL) was stirred at 100° C. for 3 hours. After cooling to room temperature, the solvent was removed in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane/methanol (30:1) to afford the title compound as a brown amorphous (2.08 g, 82%).
[0318] 1 H NMR (CDCl 3 , 270 MHz) δ: 9.72 (s, 1H), 8.03 (d, J=7.2 Hz, 2H), 7.95 (s, 1H), 7.59 (t, J=7.9 Hz, 1H), 7.46 (t, J=7.9 Hz, 2H), 4.61 (t, J=5.3 Hz, 2H), 3.92 (s, 3H), 3.83-3.73 (m, 4H), 3.41 (t, J=5.3 Hz, 2H), 3.29 (s, 3H), 2.60 (s, 3H) ppm.
[0319] MS (ESI) m/z: 397 (M+H) + , 395 (M−H)
STEP 10: Methyl 7-hydroxy-6-(3-hydroxy-3-phenylpropyl)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate
[0320] To a solution of methyl 7-hydroxy-1-(2-methoxyethyl)-2-methyl-6-(3-oxo-3-phenylpropyl)-1H-benzimidazole-5-carboxylate (2.08 g, 5.25 mmol, Step 9) in ethanol (50 mL) was added sodium borohydride (298 mg, 7.87 mmol) at room temperature. After stirring at the same temperature for 4 hours, the solvent was evaporated, and the residue was poured onto saturated sodium hydrogencarbonate aqueous solution, and the aqueous layer was extracted with ethyl acetate. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane/methanol (20:1) to afford the title compound as a brown amorphous (2.08 g, 99%).
[0321] 1 H NMR (CDCl 3 , 270 MHz) δ: 8.56 (br, 1H), 7.88 (br.s, 1H), 7.35-7.25 (m, 5H), 4.66 (dd, J=3.3 and 11.2 Hz, 1H), 4.63-4.45 (m, 2H), 3.85 (s, 3H), 3.80-3.71 (m, 2H), 3.31 (s, 3H), 3.40-3.20 (m, 2H), 2.58 (s, 3H), 2.40-2.24 (m, 1H), 2.17-2.02 (m, 1H) ppm. (OH was not observed)
[0322] MS (ESI) m/z: 399 (M+H) + , 397 (M−H) − .
STEP 11: Methyl 1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylate
[0323] A suspension of methyl 7-hydroxy-6-(3-hydroxy-3-phenylpropyl)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylate (2.00 g, 5.01 mmol, Step 10) in 85% phosphoric acid (40 mL) was stirred at 80° C. for 20 minutes. After cooling to room temperature, the mixture was poured onto ice-water (300 mL), and the solution was neutralized by 10 N sodium hydroxide aqueous solution. The aqueous layer was extracted with dichloromethane. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with ethyl acetate/methanol (gradient elution from ethyl acetate only to 20:1) to afford the title compound as a pale brown solid (1.47 g, 77%).
[0324] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.96 (s, 1H), 7.46-7.35 (m, 5H), 5.14 (dd, J=2.0 and 10.6 Hz, 1H), 4.50-4.39 (m, 2H), 3.90 (s, 3H), 3.65-3.58 (m, 2H), 3.39-3.31 (m, 2H), 3.17 (s, 3H), 2.59 (s, 3H), 2.39-2.28 (m, 1H), 2.20-2.04 (m, 1H) ppm.
[0325] MS (ESI) m/z: 381 (M+H) + .
STEP 12: 1-(2-Methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylic acid
[0326] A mixture of methyl 1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylate (1.37 g, 3.61 mmol, Step 11), 2 mol/L sodium hydroxide aqueous solution (3.60 mL, 7.21 mmol), and ethanol (20 mL) was stirred at 80° C. for 2 hours. After cooling to room temperature, 2 mol/L hydrochloric acid (3.60 mL, 7.21 mmol) was added, and the formed precipitate was collected by filtration to afford the title compound as a white solid (1.28 g, 96%).
[0327] 1 H NMR (DMSO-d 6 , 300 MHz) δ: 12.52 (s, 1H), 7.69 (s, 1H), 7.52-7.32 (m, 5H), 5.24 (d, J=8.8 Hz, 1H), 4.45-4.38 (m, 2H), 3.62-3.55 (m, 2H), 3.26-3.18 (m, 2H), 3.13 (s, 3H), 2.34-2.22 (m, 1H), 2.09-1.92 (m, 1H) ppm.
[0328] MS (ESI) m/z: 367 (M+H) + , 365 (M−H) − .
STEP 13: 1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0329] To a solution of 1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylic acid (200 mg, 0.55 mmol, Step 12), triethylamine (0.30 mL, 2.18 mmol), and O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (228 mg, 0.60 mmol) in N,N-dimethylformamide (5 mL) was added dimethylamine hydrochloride (49 mg, 0.60 mmol) at 0° C. After stirring at room temperature for 12 h, the mixture was poured onto water, and the aqueous layer was extracted with dichloromethane. The combined organic layer was dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane/methanol (20:1) to afford the title compound as a white amorphous (215 mg, quant.).
[0330] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.45-7.35 (m, 5H), 7.14 (s, 1H), 5.16 (dd, J=2.2 and 10.3 Hz, 1H), 4.52-4.35 (m, 2H), 3.69-3.58 (m, 2H), 3.18 (s, 3H), 3.15 (s, 3H), 3.2-2.7 (m, 2H), 2.90 (s, 3H), 2.58 (s, 3H), 2.40-2.10 (m, 2H) ppm.
[0331] MS (ESI) m/z: 394 (M+H) + .
Example 2
(+)-1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide and
Example 3
(−)-1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0332] The fraction-1 (68 mg) and fraction-2 (68 mg) were prepared from racemic 1-(2-methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (200 mg, Step 13 in Example 1) by HPLC as follows.
Isolation Condition
[0333] Column: CHIRALPAK AD-H (20 mm×250 mm, DAICEL)
[0334] Mobile phase: n-Hexane/Ethanol/Diethylamine (90/10/0.1)
[0335] Flow rate: 20 mL/min
(+)-1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-1)
[0336] 1 H NMR: spectrum data were identical with those of the racemate
[0337] optical rotation: [α] D 25 =+54.3° (c=0.31, Methanol)
[0338] retention time: 33 min
(−)-1-(2-Methoxyethyl)-N,N,2-trimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-2)
[0339] 1 H NMR: spectrum data were identical with those of the racemate
[0340] optical rotation: [α] D 25 =−59.1° (c=0.30, Methanol)
[0341] retention time: 39 min
Example 4
N-(2-Hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0342]
[0343] The title compound was prepared as a white solid in quantitative yield from 1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylic acid (200 mg, 0.55 mmol, Step 12 of Example 1) and 2-(methylamino)ethanol (45 mg, 0.60 mmol) by the same manner in Step 13 of Example 1.
[0344] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.48-7.33 (m, 5H), 7.14 (s, 1H), 5.16 (d, J=10.3 Hz, 1H), 4.50-4.40 (m, 2H), 3.98-3.89 (m, 2H), 3.72-3.60 (m, 2H), 3.26-3.15 (m, 2H), 3.2-2.7 (m, 2H), 3.19 (s, 3H), 2.96 (s, 3H), 2.59 (s, 3H), 2.35-1.80 (m, 2H) ppm. (OH was not observed)
[0345] MS (ESI) m/z: 424 (M+H) + .
Example 5
8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0346]
STEP 1: 7-(Benzyloxy)-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide
[0347] A mixture of 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylic acid (520 mg, 1.53 mmol, Step 5 of Example 1), dimethylamine hydrochloride (374 mg, 4.58 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (498 mg, 2.60 mmol), 1-hydroxybenzotriazole hydrate (413 mg, 3.06 mmol), and triethylamine (0.64 mL, 4.58 mmol) in N,N-dimethylformamide (10 mL) was stirred at room temperature for 1 day. The mixture was poured onto water, and the aqueous layer was extracted with ethyl acetate. The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with dichloromethane/methanol (10:1) to afford the title compound as a white solid (524 mg, 93%).
[0348] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.46-7.33 (m, 6H), 6.94 (br.s, 1H), 5.20 (s, 2H), 4.44 (t, J=5.3 Hz, 2H), 3.61 (t, J=5.3 Hz, 2H), 3.17 (s, 3H), 3.09 (br.s, 6H), 2.59 (s, 3H) ppm.
[0349] MS (ESI) m/z: 368 (M+H) + .
Step 2: 7-Hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide
[0350] A mixture of 7-(benzyloxy)-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide (483 mg, 1.31 mmol, Step 1) and 10% palladium-carbon (50 mg) in ethanol (30 mL) was stirred under hydrogen gas for 19 hours. The resulting mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo to afford the title compound as a white solid (347 mg, 95%).
[0351] 1 H NMR (CDCl 3 , 300 MHz) δ: 9.57 (br.s, 1H), 7.14 (d, J=1.5 Hz, 1H), 6.93 (d, J=1.5 Hz, 1H), 4.43 (t, J=5.1 Hz, 2H), 3.64 (t, J=5.1 Hz, 2H), 3.20 (s, 3H), 3.15 (br.s, 3H), 3.05 (br.s, 3H), 2.53 (s, 3H) ppm.
[0352] MS (ESI) m/z: 278 (M+H) + .
STEP 3: 6-[(Dimethylamino)methyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide
[0353] To a stirred solution of 7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide (1.0 g, 3.6 mmol, Step 2) and potassium carbonate (748 mg, 5.4 mmol) in N,N-dimethylformamide (36 mL) at 0° C. was added N,N-dimethylmethyleneiminium iodide (867 mg, 4.7 mmol). After stirring at the same temperature for 4 hours, the reaction mixture was quenched with saturated sodium hydrogencarbonate aqueous solution and extracted with dichloromethane. The combined organic layer was washed with brine, dried over magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on NH-gel eluting with ethyl acetate/methanol (30:1) to afford the title compound (855 mg, 71%) as a white amorphous.
[0354] 1 H NMR (CDCl 3 , 270 MHz) δ: 6.97 (s, 1H), 4.51 (t, J=5.3 Hz, 2H), 3.65-3.82 (br.s, 2H), 3.75 (t, J=5.3 Hz, 2H), 3.27 (s, 3H), 3.14 (s, 3H), 2.88 (s, 3H), 2.58 (s, 3H), 2.36 (s, 6H) ppm. (OH was not observed)
[0355] MS (ESI) m/z: 335 (M+H) + .
STEP 4: 6-[3-(4-Fluorophenyl)-3-oxopropyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide
[0356] The title compound was prepared as a brown amorphous in 86% yield from 6-[(dimethylamino)methyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide (648 mg, 1.94 mmol, Step 3) and 1-[1-(4-fluorophenyl)vinyl]pyrrolidine (556 mg, 2.91 mmol, WO9940091) by the same manner in Step 9 of Example 1.
[0357] 1 H NMR (CDCl 3 , 270 MHz) δ: 9.38 (s, 1H), 8.05 (dd, J=8.6, 5.3 Hz, 2H), 7.10 (t, J=8.6 Hz, 2H), 7.06 (s, 1H), 4.57 (t, J=5.3 Hz, 2H), 3.79 (t, J=5.3 Hz, 2H), 3.30 (s, 3H), 3.18 (s, 3H), 2.87 (s, 3H), 2.58 (s, 3H) ppm. (2×CH 2 were not observed)
[0358] MS (ESI) m/z: 428 (M+H) + , 426 (M−H) − .
STEP 5: 6-[3-(4-Fluorophenyl)-3-hydroxypropyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide
[0359] The title compound was prepared as a brown amorphous in 87% yield from 6-[3-(4-fluorophenyl)-3-oxopropyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide (713 mg, 1.67 mmol, Step 4) by the same manner in Step 10 of Example 1.
[0360] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.26 (m, 2H), 6.94 (t, J=8.8 Hz, 2H), 6.94 (s, 1H), 4.55-4.42 (m, 3H), 3.72 (br.s, 2H), 3.31 (s, 3H), 3.10 (s, 3H), 2.79 (s, 3H), 2.51 (s, 3H) ppm. (2×CH 2 , and 2×OH were not observed)
[0361] MS (ESI) m/z: 430 (M+H) + , 428 (M−H).
STEP 6: 8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0362] The title compound was prepared as a white solid in 93% yield from 6-[3-(4-fluorophenyl)-3-hydroxypropyl]-7-hydroxy-1-(2-methoxyethyl)-N,N,2-trimethyl-1H-benzimidazole-5-carboxamide (273 mg, 0.636 mmol, Step 5) by the same manner in Step 11 of Example 1.
[0363] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.40 (dd, J=8.8, 5.1 Hz, 2H), 7.14 (s, 1H), 7.11 (t, J=8.8 Hz, 2H), 5.12 (dd, J=10.3, 2.2 Hz, 1H), 4.48-4.33 (m, 2H), 3.64-3.57 (m, 2H), 3.2-2.7 (m, 2H), 3.19 (s, 3H), 3.15 (s, 3H), 2.90 (s, 3H), 2.57 (s, 3H), 2.29-2.11 (m, 2H) ppm.
[0364] MS (ESI) m/z: 412 (M+H) + .
Example 6
(+)-8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide and
Example 7
(−)-8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0365] The fraction-1 (73 mg) and fraction-2 (73 mg) were prepared from racemic 8-(4-fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (183 mg, STEP 6 in Example 5) by HPLC as follows.
Isolation Condition
[0366] Column: CHIRALCEL OJ-H (20 mm×250 mm, DAICEL)
[0367] Mobile phase: n-Hexane/2-Propanol/Diethylamine (88/12/0.1)
[0368] Flow rate: 18.9 mL/min
(−)-8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-1)
[0369] 1 H NMR: spectrum data were identical with those of the racemate
[0370] optical rotation: [α] D 24 =−44.7° (c=0.31, Methanol)
[0371] retention time: 11 min
(+)-8-(4-Fluorophenyl)-1-(2-methoxyethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-2)
[0372] 1 H NMR: spectrum data were identical with those of the racemate
[0373] optical rotation: [α] D 24 =+44.0° (c=0.30, Methanol)
[0374] retention time: 18 min
Example 8
8-(4-Fluorophenyl)-1-(3-hydroxypropyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0375]
STEP 1: 4-(Benzyloxy)-6-bromo-2-methyl-1H-benzimidazole
[0376] A mixture of N-[2-(benzyloxy)-4-bromo-6-nitrophenyl]acetamide (120 g, 329 mmol, Step 1 of Example 1) and iron powder (55.1 g, 986 mmol) in acetic acid (500 mL) was refluxed with stirring for 6 hours. After cooling to room temperature, the mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo. The residue was diluted with ethyl acetate (1.5 L). The resulted precipitates were filtered through a pad of Celite, and washed with ethyl acetate (500 mL). The filterate was concentrated in vacuo, and the residue was diluted with ethyl acetate (200 mL). The brine (800 mL) was added to the organic mixture, the resulted white precipitates were collected by filtration, and washed with water (200 mL) and diethyl ether (200 mL). The white solid was dissolved with dichloromethane/methanol (10:1, 1.0 L), dried over magnesium sulfate, and concentrated. The solid was triturated with diethyl ether (300 mL), collected by filtration, and dried in vacuo to afford the title compound as a white solid (54.7 g, 53%).
[0377] 1 H NMR (DMSO-d 6 , 270 MHz) δ: 7.63-7.28 (m, 7H), 5.38 (s, 2H), 2.69 (s, 3H) ppm. (NH was not observed.)
[0378] MS (ESI) m/z: 317 (M+H) + , 315 (M−H) − .
STEP 2: 4-(Benzyloxy)-6-bromo-2-methyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole
[0379] To a suspension of 4-(benzyloxy)-6-bromo-2-methyl-1H-benzimidazole (79.2 g, 250 mmol, Step 1) in N,N-dimethylformamide (500 mL) was added sodium hydride (60% in mineral oil, 12.0 g, 300 mmol) at 0° C. After stirring at room temperature for 20 minutes, the reaction mixture was cooled to 0° C. To the mixture was added 4-methylbenzenesulfonyl chloride (47.6 g, 250 mmol) at 0° C., and the reaction mixture was stirred at room temperature for 30 minutes. The mixture was quenched with water, and the white precipitates were collected by filtration, washed with diisopropyl ether, and dried in vacuo at 70° C. for 7 hours to afford the title compound as a white solid (116 g, 98%).
[0380] 1 H NMR (DMSO-d 6 , 270 MHz) δ: 7.98 (d, J=8.1 Hz, 2H), 7.64 (d, J=1.9 Hz, 1H), 7.53-7.34 (m, 7H), 7.22 (d, J=1.9 Hz, 1H), 5.28 (s, 2H), 2.74 (s, 3H), 2.38 (s, 3H) ppm.
[0381] MS (ESI) m/z: 471 (M+H) + , 469 (M−H) − .
STEP 3: 4-(Benzyloxy)-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide
[0382] A mixture of 4-(benzyloxy)-6-bromo-2-methyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole (53.0 g, 112 mmol, Step 2) and tetrakis(triphenylphosphine)palladium (25.9 g, 22.4 mmol) in 2 mol/L dimethylamine tetrahydrofuran solution (580 mL) was stirred at 65° C. under carbon monoxide gas (1 atm) for 32 hours. The mixture was cooled to room temperature, and diluted with ethyl acetate. The organic mixture was washed with saturated ammonium chloride aqueous solution and brine, dried over magnesium sulfate and concentrated in vacuum. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (gradient elution from 1:2 to 1:3) to afford the title compound as a white solid (21.8 g, 42%).
[0383] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.80 (d, J=8.1 Hz, 2H), 7.70 (s, 1H), 7.45 (d, J=8.1 Hz, 2H), 7.40-7.22 (m, 5H), 6.86 (s, 1H), 5.32 (s, 2H), 3.11 (br.s, 3H), 2.89 (br.s, 3H), 2.81 (s, 3H), 2.40 (s, 3H) ppm.
[0384] MS (ESI) m/z: 464 (M+H) + .
STEP 4: 4-Hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide
[0385] A mixture of 4-(benzyloxy)-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (29.0 g, 62.6 mmol, Step 3) and 10% palladium on carbon (6.0 g) in tetrahydrofuran (200 mL) was stirred under hydrogen gas (1 atm) at room temperature for 24 hours. Another 4.0 g of 10% palladium on carbon was added, and the mixture was stirred under hydrogen gas (1 atm) at room temperature for additional 6 hours. The resulted mixture was filtered through a pad of Celite, and the filtrate was concentrated in vacuo to afford the title compound as a white solid (23.0 g, 98%).
[0386] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.82 (d, J=8.1 Hz, 2H), 7.63 (s, 1H), 7.31 (d, J=8.1 Hz, 2H), 6.92 (s, 1H), 3.14 (br.s, 3H), 3.01 (br.s, 3H), 2.79 (s, 3H), 2.40 (s, 3H) ppm (—OH was not observed).
[0387] MS (ESI) m/z: 374 (M+H) + , 372 (M−H) − .
STEP 5: 5-[(Dimethylamino)methyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide
[0388] To a solution of 4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (1.00 g, 2.68 mmol, Step 4) in dichloromethane (50 mL) was added N,N-dimethylmethyleneiminium iodide (545 mg, 2.95 mmol) at room temperature and the mixture was stirred at 40° C. for 15 hours. The reaction was quenched by saturated sodium hydrogencarbonate aqueous solution. The mixture was extracted with dichloromethane. The organic layer was dried over sodium sulfate and concentrated in vacuo to afford the title compound as a yellow amorphous (1.04 g, 90%).
[0389] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.78 (d, J=8.6 Hz, 2H), 7.35 (s, 1H), 7.32-7.24 (m, 2H), 3.83-3.56 (br, 2H), 3.17 (s, 3H), 2.87 (s, 3H), 2.77 (s, 3H), 2.40 (s, 3H), 2.36 (s, 6H) ppm. (OH was not observed)
[0390] MS (ESI) m/z: 431 (M+H) + , 429 (M−H) − .
STEP 6: 5-[3-(4-Fluorophenyl)-3-oxopropyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide
[0391] The title compound was prepared as a brown solid in 52% yield from 5-[(dimethylamino) methyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (1.15 g, Step 5) and 1-[1-(4-fluorophenyl)vinyl]pyrrolidine (766 mg, WO9940091) by the same manner in Step 9 of Example 1.
[0392] 1 H NMR (CDCl 3 , 270 MHz) δ: 8.02 (dd, J=8.8, 5.1 Hz, 2H), 7.79 (d, J=8.1 Hz, 2H), 7.44 (s, 1H), 7.34-7.24 (m, 2H), 7.08 (dd, J=8.8, 8.8 Hz, 2H), 3.18 (s, 3H), 2.87 (s, 3H), 2.76 (s, 3H), 2.39 (s, 3H) ppm. (OH and 2×CH 2 were not observed)
[0393] MS (ESI) m/z: 524 (M+H) + , 522 (M−H) − .
STEP 7: 5-[3-(4-Fluorophenyl)-3-hydroxypropyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide
[0394] The title compound was prepared as a brown solid in 64% yield from 5-[3-(4-fluorophenyl)-3-oxopropyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (300 mg, Step 6) by the same manner in Step 10 of Example 1.
[0395] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.82 (d, J=8.6 Hz, 2H), 7.43 (s, 1H), 7.35-7.23 (m, 4H), 6.95 (dd, J=8.9, 8.9 Hz, 2H), 3.17 (s, 3H), 2.85 (s, 3H), 2.76 (s, 3H), 2.41 (s, 3H) ppm. (CH, 2×CH 2 , and 2×OH were not observed)
[0396] MS (ESI) m/z: 526 (M+H) + , 524 (M−H) − .
STEP 8: 8-(4-Fluorophenyl)-N,N,2-trimethyl-3,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0397] The title compound was prepared as a brown oil in 43% yield from 5-[3-(4-fluorophenyl)-3-hydroxypropyl]-4-hydroxy-N,N,2-trimethyl-1-[(4-methylphenyl)sulfonyl]-1H-benzimidazole-6-carboxamide (192 mg, Step 7) by the same manner in Step 11 of Example 1.
[0398] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.43 (dd, J=8.6, 5.3 Hz, 2H), 7.40-7.19 (br, 3H), 3.14 (s, 3H), 2.92-2.84 (br, 3H), 2.59 (s, 3H) ppm. (CH, 2×CH 2 , and NH were not observed)
[0399] MS (ESI) m/z: 354 (M+H) + , 352 (M−H).
STEP 9: 1-(3-{[tert-Butyl(dimethyl)silyl]oxy}propyl)-8-(4-fluorophenyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0400] To a solution of 8-(4-fluorophenyl)-N,N,2-trimethyl-3,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (52.0 mg, 0.147 mmol, Step 8) in N,N-dimethylformamide (1.5 mL), was added sodium hydride (7.1 mg, 0.18 mmol) at 0° C. and the mixture was stirred at 0° C. for 30 minutes. Then (3-bromopropoxy)(tert-butyl)dimethylsilane (48.4 mg, 0.191 mmol) was added to the mixture at 0° C. The mixture was allowed to warm to room temperature, stirred for 4 hours and left at the same temperature overnight. The reaction was quenched by saturated ammonium chloride aqueous solution. The mixture was extracted with ethyl acetate. The combined organic layers were washed with water and brine. It was dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC eluting with hexane/ethyl acetate (1:1 and then 1:4) to afford the title compound as a brown oil (35.5 mg, 46%).
[0401] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.41 (dd, J=8.6, 5.3 Hz, 2H), 7.16-7.06 (m, 3H), 5.11 (dd, J=10.2, 2.3 Hz, 1H), 4.31 (t, J=7.3 Hz, 2H), 3.41 (t, J=5.3 Hz, 2H), 3.2-2.7 (m, 2H), 3.15 (s, 3H), 2.90 (s, 3H), 2.57 (s, 3H), 2.37-2.02 (m, 2H), 1.90 (tt, J=6.6, 6.6 Hz, 2H), 0.88 (s, 9H), −0.01 (s, 6H) ppm.
[0402] MS (ESI) m/z: 526 (M+H) + .
STEP 10: 8-(4-Fluorophenyl)-1-(3-hydroxypropyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0403] To the solution of 1-(3-{[tert-butyl(dimethyl)silyl]oxy}propyl)-8-(4-fluorophenyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (35 mg, 0.067 mmol, Step 9) in tetrahydrofuran was added 1M solution of tetrabutylammonium fluoride in tetrahydrofuran (0.1 mL). The mixture was stirred at room temperature for 2.5 hours. The reaction was quenched by saturated ammonium chloride aqueous solution. The mixture was extracted with ethyl acetate. The combined organic layers were washed with water and brine, dried over sodium sulfate, and concentrated in vacuo. The residue was purified by preparative TLC eluting with dichloromethane/methanol (20:1). The obtained product was triturated in hexane to afford the title compound as a pale yellow solid (8.6 mg, 31%)
[0404] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.43 (dd, J=9.2, 5.3 Hz, 2H), 7.16-7.06 (m, 3H), 5.12 (dd, J=10.2, 2.3 Hz, 1H), 4.35 (t, J=6.9 Hz, 2H), 3.46 (t, J=5.6 Hz, 2H), 3.2-2.7 (m, 2H), 3.15 (s, 3H), 2.90 (s, 3H), 2.57 (s, 3H), 2.37-2.06 (m, 2H), 2.02-1.88 (m, 2H) ppm. (OH was not observed)
[0405] MS (ESI) m/z: 412 (M+H) + .
Example 9
8-(4-Fluorophenyl)-1-(isoxazol-3-ylmethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0406]
STEP 1: 3-(Bromomethyl)isoxazole
[0407] To a solution of isoxazol-3-ylmethanol (100 mg, 1.01 mmol, EP87953) in dichloromethane (10 mL) was added phosphorus tribromide (820 mg, 3.03 mmol) at 0° C. The mixture was stirred at room temperature for 3 hours. The reaction was quenched by saturated sodium hydrogencarbonate aqueous solution. The mixture was extracted twice with dichloromethane. The combined organic layer was dried over sodium sulfate and concentrated with N,N-dimethylformamide (1.0 mL) in vacuo to afford the title compound as a N,N-dimethylformamide solution.
STEP 2: 8-(4-Fluorophenyl)-1-(isoxazol-3-ylmethyl)-N,N,2-trimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0408] To a solution of 8-(4-fluorophenyl)-N,N,2-trimethyl-3,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (50.0 mg, 0.141 mmol, Step 8 of Example 8) in N,N-dimethylformamide (1.4 mL), was added sodium hydride (6.7 mg, 0.17 mmol) at 0° C. and the mixture was stirred at 0° C. for 30 minutes. Then a solution of 3-(bromomethyl)isoxazole in N,N-dimethylformamide (1.0 mL, Step 1) was added to the mixture at 0° C. The mixture was allowed to warm to room temperature, stirred for 4 hours and left at the same temperature overnight. The reaction was quenched by saturated ammonium chloride aqueous solution. The mixture was extracted twice with ethyl acetate. The combined organic layer was washed with water and brine, dried over sodium sulfate, and concentrated in vacuo. The residue was purified by preparative TLC eluting with hexane/ethyl acetate (1:1, twice), then dichloromethane/methanol (20:1, twice) to afford the title compound as a pale yellow solid (23.5 mg, 38%).
[0409] 1 H NMR (CDCl 3 , 270 MHz) δ: 8.31 (d, J=1.5 Hz, 2H), 7.31 (dd, J=8.8, 5.1 Hz, 2H), 7.17 (s, 1H), 7.06 (dd, J=8.4, 8.4 Hz, 1H), 6.03 (d, J=1.5 Hz, 1H), 5.66 (d, J=16.1 Hz, 1H), 5.57 (d, J=16.1 Hz, 1H), 5.13 (dd, J=10.3, 2.2 Hz, 1H), 3.2-2.7 (m, 2H), 3.16 (s, 3H), 2.91 (s, 3H), 2.57 (s, 3H), 2.35-2.02 (m, 2H) ppm.
[0410] MS (ESI) m/z: 435 (M+H) + .
Example 10
N,N-Di[ 2 H 3 ]methyl-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0411]
[0412] A mixture of 1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylic acid (200 mg, 0.55 mmol, Step 12 of Example 1), N,N-di[ 2 H 3 ]methylamine hydrochloride (96 mg, 1.09 mmol), N,N-diisopropylethylamine (0.38 mL, 2.18 mmol), 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (157 mg, 0.82 mmol), and 1-hydroxybenzotriazole hydrate (125 mg, 0.82 mmol) in 1-methyl-2-pyrrolidinone (3 mL) was stirred at room temperature for 8 hours. Then, the mixture was poured onto water (30 mL), and the aqueous layer was extracted with ethyl acetate. The combined organic layer was dried over magnesium sulfate and concentrated in vacuo. The residue was purified by column chromatography on NH-gel eluting with dichloromethane/methanol (20:1) to afford the title compound as a white amorphous (175 mg, 80%).
[0413] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.44-7.34 (m, 5H), 7.13 (s, 1H), 5.15 (dd, J=2.6 and 10.6 Hz, 1H), 4.50-4.35 (m, 2H), 3.68-3.56 (m, 2H), 3.2-2.7 (m, 2H), 3.18 (s, 3H), 2.57 (s, 3H), 2.35-2.10 (m, 2H).
[0414] MS (ESI) m/z: 400 (M+H) + .
Example 11
8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0415]
STEP 1: 7-(Benzyloxy)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide
[0416] The title compound was prepared as a white amorphous in 99% yield from 7-(benzyloxy)-1-(2-methoxyethyl)-2-methyl-1H-benzimidazole-5-carboxylic acid (5.00 g, 14.7 mmol, Step 5 of Example 1) and 2-(methylamino)ethanol (1.21 g, 16.2 mmol) by the same manner in Step 13 of Example 1.
[0417] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.43-7.39 (m, 6H), 6.97 (bs, 1H), 5.20 (s, 2H), 4.45 (t, J=5.1 Hz, 2H), 3.98-3.81 (m, 2H), 3.81-3.75 (m, 2H), 3.61 (t, J=5.1 Hz, 2H), 3.18 (s, 3H), 3.12 (s, 3H), 2.60 (s, 3H) ppm. (OH was not observed)
[0418] MS (ESI) m/z: 398 (M+H) + .
STEP 2: 7-Hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide
[0419] The title compound was prepared as a yellow oil in quantitative yield from 7-(benzyloxy)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide (1.15 g, 2.89 mmol, Step 1) by the same manner in Step 7 of Example 1.
[0420] 1 H NMR (DMSO-d 6 , 270 MHz) δ: 7.50-6.99 (m, 1H), 6.81 (s, 1H), 4.61-4.31 (m, 2H), 4.04-3.37 (m, 6H), 3.27 (s, 3H), 3.09 (s, 3H), 2.58 (s, 3H) ppm. (2×OH were not observed)
[0421] MS (ESI) m/z: 308 (M+H) +
STEP 3: 6-[(Dimethylamino)methyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide
[0422] The title compound was prepared as a colorless oil in 45% yield from 7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide (500 mg, 1.63 mmol, Step 2) by the same manner in Step 3 of Example 5.
[0423] 1 H NMR (CDCl 3 , 270 MHz) δ: 6.99 (s, 1H), 4.61-4.43 (m, 2H), 4.43-3.54 (m, 9H), 3.28 (s, 3H), 2.94 (s, 2H), 2.58 (s, 3H), 2.36 (s, 6H) ppm. (2×OH were not observed)
[0424] MS (ESI) m/z: 365 (M+H) + . 363 (M−H) − .
STEP 4: 1-[1-(2,4-Difluorophenyl)vinyl]pyrrolidine
[0425] To a solution of 1-(2,4-difluorophenyl)ethanone (10.0 g, 64.0 mmol) and pyrrolidine (32.1 mL, 384 mmol) in hexane (150 mL) was added titanium tetrachloride (3.86 mL, 35.2 mmol) dropwise at 0° C. over 15 minutes. The reaction mixture was stirred at room temperature for 24 hours and filtered. The filtrate was evaporated in vacuo to give pale yellow oil, which was distilled under reduced pressure (0.3 mmHg, 90-120° C.) to give the title compound as a pale yellow oil (4.90 g, 36%).
[0426] 1 H NMR (CDCl 3 , 300 MHz) δ: 7.33-7.25 (m, 1H), 6.91-6.76 (m, 2H), 3.81 (s, 1H), 3.68 (s, 1H), 3.11-2.98 (m, 4H), 1.92-1.78 (m, 4H) ppm.
STEP 5: 6-[3-(2,4-Difluorophenyl)-3-oxopropyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide
[0427] The title compound was prepared as a white solid in 40% yield from 6-[(dimethylamino)methyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide (1.16 g, 3.19 mmol, Step 3) and 1-[1-(2,4-difluorophenyl)vinyl]pyrrolidine (1.00 g, 4.78 mmol, Step 4) by the same manner in Step 9 of Example 1.
[0428] 1 H NMR (CDCl 3 , 270 MHz) δ: 9.10 (br s, 1H, OH), 7.96 (q, J=8.1 Hz, 1H), 7.07 (s, 1H), 7.02-6.74 (m, 2H), 4.67-4.42 (m, 2H), 4.03-3.80 (m, 8H), 3.31 (s, 3H), 2.92 (s, 3H), 2.59 (s, 3H) ppm. (CH 2 and OH were not observed)
[0429] MS (ESI) m/z: 476 (M+H) + , 474 (M−H) − .
STEP 6: 6-[3-(2,4-Difluorophenyl)-3-hydroxypropyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide
[0430] The title compound was prepared as a white solid in quantitative yield from 6-[3-(2,4-difluorophenyl)-3-oxopropyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide (617 mg, 1.30 mmol, Step 5) by the same manner in Step 10 of Example 1.
[0431] 1 H NMR (CDCl 3 , 270 MHz) δ: 7.67-7.38 (m, 1H), 7.12 (s, 1H), 6.95-6.47 (m, 2H), 4.99-4.70 (m, 1H), 4.70-4.29 (m, 2H), 4.07-3.88 (m, 2H), 4.07-2.80 (m, 8H), 3.42 (s, 3H), 2.92 (s, 3H), 2.57 (s, 3H) ppm. (3×OH were not observed)
[0432] MS (ESI) m/z: 478 (M+H) + , 476 (M−H) − .
STEP 7: 8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0433] The title compound was prepared as a white solid in 64% yield from 6-[3-(2,4-difluorophenyl)-3-hydroxypropyl]-7-hydroxy-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1H-benzimidazole-5-carboxamide (640 mg, 0.21 mmol, Step 6) by the same manner in Step 11 of Example 1.
[0434] 1 H NMR (CDCl 3 , 270 MHz) δ: 9.72 (s, 1H), 8.03 (d, J=7.2 Hz, 2H), 7.95 (s, 1H), 7.59 (t, J=7.9 Hz, 1H), 7.46 (t, J=7.9 Hz, 2H), 4.61 (t, J=5.3 Hz, 2H), 3.92 (s, 3H), 3.83-3.73 (m, 4H), 3.41 (t, J=5.3 Hz, 2H), 3.29 (s, 3H), 2.60 (s, 3H) ppm.
[0435] MS (ESI) m/z: 460 (M+H) + .
Example 12
(−)-8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide and
Example 13
(+)-8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide
[0436] The fraction-1 (158 mg) and fraction-2 (148 mg) were prepared from racemic 8-(2,4-difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (356 mg, STEP 7 in Example 11) by chiral SFC as follows.
Isolation Condition
[0437] Apparatus: Berger MultiGram II™ (Mettler-Toledo)
[0438] Column: DAICEL CHIRALPAK AD-H (20 mm×250 mm, DAICEL)
[0439] Column temperature: 35° C.
[0440] Outlet pressure: 100 bar
[0441] Mobile phase: CO2/0.1% Diethylamine in 2-Propanol (80/20)
[0442] Flow rate: 40 mL/min
(−)-8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-1)
[0443] 1 H NMR: spectrum data were identical with those of the racemate
[0444] optical rotation: [α] D 21 =−22.9° (c=0.21, Methanol)
[0445] retention time: 10 min
(+)-8-(2,4-Difluorophenyl)-N-(2-hydroxyethyl)-1-(2-methoxyethyl)-N,2-dimethyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxamide (fraction-2)
[0446] 1 H NMR: spectrum data were identical with those of the racemate
[0447] optical rotation: [α] D 21 =+24.8° (c=0.23, Methanol)
[0448] retention time: 12 min
[0000] Following Examples 14 and 15 were prepared from
1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole-5-carboxylic acid (Step 12 of Example 1) and corresponding various amines according to the procedure described in Step 13 of Example 1.
[0000]
Example 14
5-[(3-Fluoroazetidin-1-yl)carbonyl]-1-(2-methoxyethyl)-2-methyl-8-
phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole
White solid 1 H NMR (CDCl 3 , 300 MHz) δ : 7.51-7.33 (m, 5H), 7.22 (s, 1H), 5.33 (br d, J = 56.5 Hz, 1H), 5.15 (dd, J = 11.0, 2.2 Hz, 1H), 4.58-4.02 (m, 6H), 3.66-3.57 (m, 2H), 3.22-2.97 (m, 2H), 3.18 (s, 3H), 2.58 (s, 3H), 2.33-2.22 (m, 1H), 2.20-2.04 (m, 1H) ppm. MS (ESI) m/z: 424 (M + H) + .
Example 15
5-(Azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-
tetrahydrochromeno[7,8-d]imidazole
White solid 1 H NMR (CDCl 3 , 300 MHz) δ : 7.50-7.32 (m, 5H), 7.21 (s, 1H), 5.15 (dd, J = 11.0, 2.2 Hz, 1H), 4.49-4.39 (m, 2H), 4.29-3.93 (m, 4H), 3.66-3.58 (m, 2H), 3.26-2.95 (m, 2H), 3.17 (s, 3H), 2.57 (s, 3H), 2.38-2.25 (m, 3H), 2.18-2.04 (m, 1H) ppm. MS (ESI) m/z: 406 (M + H) + .
Example 16
(−)-5-(Azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole and
Example 17
(+)-5-(Azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole
[0449] The fraction-1 (86 mg) and fraction-2 (82 mg) were prepared from racemic 5-(azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole (230 mg, Example 15) by HPLC as follows.
Isolation Condition
[0450] Column: CHIRALCEL OD-H (20 mm×250 mm, DAICEL)
[0451] Mobile phase: n-Hexane/Ethanol/Diethylamine (85/15/0.1)
[0452] Flow rate: 20 mL/min
(−)-5-(Azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole (fraction-1)
[0453] 1 H NMR: spectrum data were identical with those of the racemate
[0454] optical rotation: [α] D 21 =−23.5° (c=0.21, Methanol)
[0455] retention time: 15.7 min
(+)-5-(Azetidin-1-ylcarbonyl)-1-(2-methoxyethyl)-2-methyl-8-phenyl-1,6,7,8-tetrahydrochromeno[7,8-d]imidazole (fraction-2)
[0456] 1 H NMR: spectrum data were identical with those of the racemate
[0457] optical rotation: [α] D 21 =+25.0° (c=0.20, Methanol)
[0458] retention time: 21.7 min
[0459] All publications, including but not limited to, issued patents, patent applications, and journal articles, cited in this application are each herein incorporated by reference in their entirety.
[0460] Although the invention has been described above with reference to the disclosed embodiments, those skilled in the art will readily appreciate that the specific experiments detailed are only illustrative of the invention. It should be understood that various modifications could be made without departing from the spirit of the invention. | This invention relates to compounds of the formula (I): or a pharmaceutically acceptable salt thereof, wherein: R 1 , R 2 , R 3 , R 4 , A and E are each as described herein or a pharmaceutically acceptable salt, and compositions containing such compounds and the method of treatment and the use, comprising such compounds for the treatment of a condition mediated by acid pump antagonistic activity such as, but not limited to, as gastrointestinal disease, gastroesophageal disease, gastroesophageal reflux disease (GERD), laryngopharyngeal reflux disease, peptic ulcer, gastric ulcer, duodenal ulcer, NSAID-induced ulcers, gastritis, infection of Helicobacter pylori , dyspepsia, functional dyspepsia, Zolliπger-Ellison syndrome, non-erosive reflux disease (NERD), visceral pain, cancer, heartburn, nausea, esophagitis, dysphagia, hypersalivation, airway disorders or asthma. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Stage of International Application No. PCT/EP2014/069879 filed Sep. 18, 2014, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP13192141 filed Nov. 8, 2013. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The present invention relates to a module for a thermal power plant for condensing expelled vapors and cooling turbine effluent from the drained turbine.
BACKGROUND OF INVENTION
[0003] Proper function of a steam turbine in a thermal power plant requires a shaft-sealed steam system and a drainage system.
[0004] The shaft-sealed steam system has the object of preventing air ingress into the steam turbine and also steam egress from the steam turbine into a power house. For that reason, air and steam are drawn out of the shaft-sealed steam system in a controlled manner. The air-steam mixture aspirated in that context, termed vapor steam, is conveyed to a vapor steam condenser. There, the steam fraction of the vapor steam condenses. The resulting condensate is conveyed to a main condenser of the thermal power plant. The air is conducted into the atmosphere. Atmosphere primarily refers to the air being discharged into a region in which approximately atmospheric pressure prevails. This can for example be a power house of the thermal power plant. In order to be able to better integrate the vapor steam condenser into a cooling circuit of the thermal power plant, the vapor steam condenser is configured for the available quantity of cooling water.
[0005] The drainage system serves for discharging water that accumulates in the steam turbine. This water still contains steam which must either be removed from the water or condensed. At this point, it should be noted that, in the context of this application and unless otherwise stated, water is to be understood as liquid water and steam as water steam.
SUMMARY OF INVENTION
[0006] An object of the invention is to provide a simplified construction for the above-mentioned requirements, namely turbine drainage and vapor steam condensation.
[0007] This object is achieved with the features of the independent claim. Dependent claims indicate advantageous developments. To achieve the object, there is proposed a module for a thermal power plant for condensing vapor steam and for cooling turbine waste water from turbine drainage. Such a module, which performs both functions, makes it possible to reduce the complexity of construction. As described in the introduction, it is common in the prior art to configure the vapor steam condenser for the available quantity of water in the cooling circuit. This generally results in the vapor steam condenser being oversized. A common module for condensing vapor steam and for cooling the turbine waste water makes it possible to remove this drawback. It is expedient in this context that condensate obtained by condensing vapor steam can be used for cooling the turbine waste water. It is thus possible to provide cooling water only for condensing vapor steam. Additional provision of cooling water for cooling the turbine waste water becomes unnecessary.
[0008] For conversion, a first unit of the module is designed to condense the vapor steam and a second unit is designed to cool the turbine waste water, wherein condensate produced in the first unit can be passed to the second unit. It is expedient in that context that, in the first unit, the condensing of the vapor steam can take place essentially without taking into account the cooling of the turbine waste water. By virtue of the possibility of passing the produced condensate to the second unit, in which the cooling of the turbine waste water takes place, it is possible to realize a synergistic effect between the two units. In particular, for the proper understanding of the following explanations, it should be stated that the second unit generally has an upper and a lower region.
[0009] In one embodiment of the module, a condensate line serves to pass condensate from the first unit to the second unit, wherein in particular a steam trap is present in the condensate line. This permits proper transfer of the condensate.
[0010] In one embodiment of the module, cooling water, in particular cooling water which is provided for standpipes of a main condenser of the thermal power plant, can flow through the first unit. In that context, the main condenser is to be understood as that condenser in which is condensed the steam flowing out of the steam turbine, more precisely out of that part of the steam turbine which is flowed through last. The obtained condensate is used as feed water which is to be heated and evaporated again.
[0011] In one embodiment of the module, cooling water can be used in the second unit after flowing through the first unit, in particular for injection into the second unit. In that context, injection is advantageously carried out in an upper region of the second unit. Insofar as has been stated above that no additional cooling water need be provided for cooling of the turbine waste water, in the case of this embodiment the statement should be clarified to the effect that cooling water which has already been used for condensing vapor steam can be used once again for cooling the turbine waste water.
[0012] In one embodiment of the module, there is present, in the first unit, an outlet through which air, carried with the vapor steam into the first unit, can be discharged, in particular to the atmosphere, after condensation of the vapor steam. The vapor steam contains a considerable quantity of air. While the contained steam can be condensed and the condensate can for example be reused as feed water, the air must be removed. In that context, the air is advantageously discharged into the atmosphere. As stated in the introduction, this means for example venting the air into the power house. The outlet in the first unit is normally installed in an upper region of the first unit.
[0013] In one embodiment of the module, the second unit has an inlet for turbine waste water which is in particular connected in the upper region of the second unit. This allows the turbine waste water which is to be cooled to flow from top to bottom through the second unit, and to be cooled in the process.
[0014] In one embodiment of the module, the second unit has an outlet to the main condenser, wherein the outlet is in particular connected in a lower region of the second unit. This allows the cooled turbine waste water, in which the entrained steam has been condensed by means of the cooling, to pass to the main condenser. In addition to the turbine waste water, it may also be possible for introduced condensate from the first unit and introduced cooling water to be discharged at the same time. The main condenser generally has a collecting box whence condensed steam can be supplied to the boiler feed water by means of main condensate pumps. Consequently, the turbine waste water can advantageously be conveyed into the collecting box and thence supplied to the boiler feed water. In order to convey the turbine waste water to the main condenser, that is to say generally into the collecting box, it is frequently expedient to provide a pump. This makes it possible, where necessary, for the outlet to the main condenser to lie geodetically below the main condenser. A pump can also serve for controlled discharge of the cooled turbine waste water.
[0015] In one embodiment of the module, there is a connection line, serving for pressure equalization, between the second unit and the main condenser, wherein the connection line is in particular connected in the upper region of the second unit. This can make it possible for the same pressure to prevail in the second unit and in the main condenser.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be described in greater detail below with reference to a FIGURE.
[0017] The sole FIGURE shows, schematically, a module according to aspects of the invention.
DETAILED DESCRIPTION OF INVENTION
[0018] The FIGURE shows a first unit 1 which comprises a heat exchanger 2 for condensing vapor steam. Cooling water is conveyed through a cooling water supply line 3 into the first unit 1 , more precisely into the heat exchanger 2 , for condensing vapor steam. The vapor steam is supplied via a vapor steam supply line 4 . The vapor steam is cooled by the exchange of heat in the heat exchanger 2 . This initiates condensation. The heat released during cooling of the vapor steam and above all during condensation is transferred to the cooling water. The cooling water flows through a cooling water discharge line 5 to a standpipe. Air contained in the vapor steam is drawn off through an air discharge line 6 serving as an outlet and is conveyed into a machine space of the thermal power plant. A fan 7 , which is arranged in the air discharge line 6 , serves for drawing-off.
[0019] The condensate produced in the first unit 1 is conveyed, via a condensate line 8 and with the aid of a steam trap 9 installed in the condensate line 8 , into a second unit 10 . The second unit 10 comprises, in essence, a drainage tank 11 . In that context, the condensate line 8 opens into an upper region of the second unit 10 . Opposite this in the second unit, there is arranged a turbine waste water supply line 12 as inlet for the turbine waste water. The turbine waste water supply line 12 conveys, into the drainage tank 11 , turbine waste water which, as indicated by the arrows, originates in turbines of the thermal power plant. In the drainage tank 11 , the turbine waste water flows downward.
[0020] Part of the cooling water flowing out of the first unit 1 through the cooling water discharge line 5 is diverted and flows through a cooling water injection line 13 , whence it is injected into the upper region of the drainage tank 11 . The injected cooling water and the injected condensate cool the introduced turbine waste water in the drainage tank 11 . This condenses the steam which is entrained by the turbine waste water and is at first still contained in the turbine waste water. The turbine waste water which is largely freed from steam, the injected cooling water and the introduced condensate collect in a lower region of the drainage tank 11 . Thence, it is conveyed through a condensate discharge line 14 serving as outlet, with the aid of a pump 15 contained in the condensate discharge line 14 , into a main condenser (not shown) of the thermal power plant. A pressure-equalizing line 16 , arranged at the top of the drainage tank 11 , is also connected to the main condenser and serves for pressure equalization between the drainage tank 11 and the main condenser, such that the drainage tank 11 is at the pressure of the main condenser.
[0021] In a conventional thermal power plant producing several hundred megawatts, a power of at most 600 kW is sufficient for the heat exchanger 2 in the above-described module. A temperature difference of 10 K is sufficient. No more than 15 kg/s of cooling water are required.
[0022] Although the invention has been described and illustrated in more detail by way of the preferred exemplary embodiment, the invention is not restricted by the disclosed examples and other variations can be derived herefrom by a person skilled in the art without departing from the scope of protection of the invention. | A module for a thermal power plant for condensing expelled vapors and cooling turbine effluent from the drained turbine includes a first unit designed to condense expelled vapors as well as a second unit designed to cool the turbine effluent, condensate from the first unit being transferable to the second unit. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is concerned with spinodal alloys.
2. Description of the Prior Art
Spinodal copper-nickel-tin alloys have been developed recently as commercially viable substitutes for copper-beryllium and phosphor-bronze alloys currently prevalent in the manufacture of articles such as electrical wire, springs, connectors, and relay elements. U.S. Pat. No. 3,937,638, issued to J. T. Plewes on Feb. 10, 1976, (Case 2) and assigned to the assignee hereof, discloses copper-nickel-tin alloys which, when cold worked and aged according to a critical schedule, exhibit unexpectedly high levels of yield strength in combination with high levels of ductility. For example, a copper-nickel-tin alloy containing 9% nickel, 6% tin, and remainder copper, when homogenized, cold worked by an amount corresponding to an area reduction of 99%, and aged for 75 minutes at a temperature of 300° C., exhibits a yield strength of 182,000 pounds per square inch and undergoes 52% reduction in cross-sectional area under tension before failure.
The composition of these alloys is characterized in that such alloys are in a single phase state at temperatures near the melting point of the alloy but in a two-phase state at room temperature; the spinodal structure is characterized in that, at room temperature, the second phase is finely dispersed throughout the first phase rather than being situated at the first phase grain boundaries.
The treatment which develops the spinodal grain structure in preference to an undesirable second phase precipitation at the grain boundaries calls for homogenizing, cold working and aging the alloy. Specifically, the aging temperature is required to be in the vicinity of an optimal temperature T d dependent primarily on the amount of cold work performed but must not exceed the so-called reversion temperature T m which is dependent primarily upon the composition of the alloy. Table I taken from U.S. Pat. No. 3,937,638, shows reversion temperatures for a number of copper-nickel-tin alloys which develop a spinodal structure when properly cold worked and aged.
SUMMARY OF THE INVENTION
It has been discovered that the predominantly spinodal two-phase structure obtained in certain copper-nickel-tin alloys by an appropriate cold working and aging treatment is essentially retained in the presence of significant amounts of Fe, Zn, Mn, Zr, Nb, Cr, Al, or Mg. The addition of such fourth elements is of interest for reasons such as cost reduction, facilitating hot working, increasing ductility or strength, and lowering the amount of cold work required for achieving the spinodal structure.
DETAILED DESCRIPTION
Copper-nickel-tin alloys of a composition containing from 2-20% nickel, from 2-8% tin, and remainder copper have been found to develop an essentially spinodal structure even when certain fourth elements are substituted for corresponding amounts of copper.
While a neutral effect on alloy properties might have reasonably been foreseen if amounts of up to 2% by weight of Fe, Zn, or Mn were present in the alloy, it has been ascertained that these elements may actually be present in amounts in excess of 2% and that even amounts significantly in excess of 5% can be tolerated. Specifically, amounts of Fe of up to 15%, of Zn of up to 10%, or of Mn of up to 15% can replace corresponding amounts of copper in the interest of reducing the cost of the alloy. If more than one of the elements Fe, Zn and Mn is present in the alloy, their combined amount should preferably not exceed 15% by weight. While replacing copper with Zn or Mn does not significantly change the mechanical properties of the worked and aged alloy, replacing copper with iron has, aside from cost reduction, the additional beneficial effect of increasing formability. Conversely, in the presence of iron smaller amounts of cold work are sufficient to achieve a desired level of ductility as compared with the amount required for the corresponding basic copper-nickel-tin alloy.
In contrast to the relatively large amounts of iron, zinc or manganese which may beneficially replace copper in spinodal alloys relatively small amounts of the elements Zr, Nb, Cr, Al or Mg are recommended. Specifically, Zr added in an amount of from 0.05 to 0.2% by weight prevents surface cracking and alligatoring during hot working of the cast ingot. The presence of Nb in an amount of from 0.1 to 0.3% or Cr in an amount of from 0.5 to 1.0% by weight, enhances ductility of the worked alloy. The presence of Mg in an amount of from 0.5 to 1.0% or Al in an amount of from 0.5 to 1.5% by weight leads to an alloy whose properties correspond to those of copper-nickel-tin alloys of significantly greater tin content. Since the price of Al or Mg is a fraction of that of tin, considerable savings can be achieved by their use. If present in combination the total amount of the elements Zr, Nb, Cr, Al, and Mg should peferably not exceed 1.5% and, if present in combination with Fe, Zn, or Mn, the total amount of elements other than Cu, Ni, and Sn should preferably not exceed 15% by weight.
The effects of the presence of fourth elements were experimentally investigated at various levels of cold work and corresponding aging temperatures. To exemplify such effects, Table II shows mechanical properties of a reference alloy and of four alloys which differ from the reference alloy in that an amount of a fourth element replaces a corresponding amount of copper. The reference alloy contains 9% nickel, 6% tin and remainder copper; the reference alloy as well as the four quaternary alloys were cold worked by an amount corresponding to a 35% reduction in area and aged for 20 hours at a temperarture of 350° C. Shown are, for each alloy, the elastic limit under tension, the area reduction on fracture under tension and the smallest bend radius achievable without fracture. It can be seen from Table II that the quaternary alloys, when compared to the reference alloy, have superior ductility and formability as measured by area reduction and bend radius, respectively, and that the strength of these alloys is comparable or superior to that of the reference alloy.
A second group of examples is shown in Table III. Here too, the reference alloy contains 9% nickel, 6% tin, and remainder copper; however, the reference alloy of Table III as well as the quaternary alloys of examples 5-9 were cold worked by an amount of 99% reduction in area and aged for 10 minutes at 350° C. It can be seen from Table III that, except for the alloy containing Al, the quaternary alloys have properties comparable to those of the reference alloy. While the aluminum alloy is less ductile that the reference alloy, its high strength combined with adequate ductility is indicative of a spinodal structure.
TABLE I______________________________________Composition Reversion Temp(wt. % Ni, Wt. % Sn, Rom. Cu) (T.sub.m) (±5° C.)______________________________________31/2% Ni 21/2% Sn 401° C. 5% Ni 5% Sn 458° C. 7% Ni 8% Sn 502° C. 9% Ni 6% Sn 508° C.101/2% Ni 41/2% Sn 530° C.12% Ni 8% Sn 555° C.______________________________________
TABLE II______________________________________ Area Reduction4th Element Elastic Limit On Fracture Bend______________________________________Reference -- 131,000 psi 6% 15tEx. 1 9% Fe 131,000 52% 1tEx. 2 0.2% Nb 144,000 41% 2tEx. 3 0.7% Cr 128,000 50% 1tEx. 4 1.5% Mg 151,000 57% 2t______________________________________
TABLE III______________________________________ Area Reduction4th Element Elastic Limit On Fracture Bend______________________________________Reference -- 167,000 psi 50% 2tEx. 5 5% Zn 160,000 55% 1tEx. 6 9% Mn 183,000 42% 1tEx. 7 1% Mg 191,000 57% 2tEx. 8 1% Al 210,000 8% 20tEx. 9 .15% Zr 183,000 40% 4t______________________________________ | Copper alloys are disclosed which contain nickel and tin and Fe, Zn, Mn, Zr, Nb, Cr, Al, or Mg in amounts within specified limits. When cold worked and aged according to a critical schedule these alloys develop a predominantly spinodal structure which renders them strong as well as ductile. The disclosed alloys are useful, for example, in the manufacture of components of electrical apparatus such as springs, connectors and relay elements. | 2 |
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates generally to disk drives comprising thin film magnetic transducers and, in particular to improvements in such transducers and their electrical connection in the drives for preventing capacitive coupling between the magnetic pole tips of the transducers and adjacent disks.
b) Background Art
In current computer technology, the common mass storage device is a hard disk drive wherein data is stored on disks as magnetic patterns on a thin film of magnetic material on the surface of the disk. The data is recorded and read by the thin film magnetic transducer or "head". Within the magnetic thin film transducer is a magnetic circuit comprising a thin film pole structure which is wrapped around or encircles the turns of a flat, spirally wound coil. The thin film pole structure comprises spaced pole tips beyond the outer periphery of the coil, defining a magnetic gap therebetween. The transducer is positioned so that the pole tips scan a disk surface as the disk rotates. The coil is connected in an amplifier circuit which maintains the coil at a potential above the potential of the disks, usually 5 volts. The coil is insulated from the magnetic circuit with a photo-resistive material which is ideally a high resistance insulator, but may have portions with poor insulating qualities due to imperfections, such as tiny holes in the photo-resistive material or extraneous pieces of metal left on the photo-resistive material during processing which capacitively couples the coil to the pole tips. There is therefore, often a charge present on the pole tips of the transducer. A problem occurs when the transducer comes near a peak or other anomaly on the disk and discharges occur from the pole tips to the disk. Electrical discharge from the pole tips of the transducer to the disk can destroy a thin film transducer. Further, the noise created by a less than damaging electrical discharge can cause errors in reading data from the disk. In addition, there are always displacement currents due to variable capacitive coupling between the pole tips and the grounded disk. Electrostatic shielding and elimination of the potential difference between the pole tips and the thin film metallic disk is therefore needed to prevent the introduction of noise into the disk drive electronics.
One method of avoiding this problem has been to apply a bias voltage to the disk which is equal to the amplifier voltage on the transducer, thereby placing the disk and the transducer at the same potential. One advantage to this technique is that any transducer can be used with the disk being charged to meet the potential of the transducer. However, this adds complexity in disk drive manufacturing and the resultant possibility of poor yields and high component costs.
U.S. Pat. No. 4,317,149 to Elser et al discloses a magnetic head assembly having conductive strips that function as bypass paths to discharge static electrical charges at a distance from the effective magnetic pole pieces and transducing gap.
U.S. Pat. No. 4,761,699 to Ainslie et al teaches a method for attaching a slider to a suspension in a data recording disk file using reflowed solder balls instead of epoxy binding to avoid static discharge from the pole tips of the transducer to the disk.
U.S. Pat. No. 4,800,454 to Schwarz et al discloses a method of static charge protection for magnetic thin film transducers which uses a conductor which makes electrical contact with the flyer body and with the magnetic core to prevent electrostatic discharge between the flyer body and the pole tip. An opening is formed in the insulating layer between the thin film transducer and the conducting substrate.
A problem occurs with this technique of static charge protection in that the flyer body is mildly conducting so that a charge can build up and subsequently discharge from the pole tip to the disk. A problem is also presented by the requirement in Schwarz et al of forming an opening in the insulating layer between the flyer body and the magnetic core which requires going through up to 10 microns of Al 2 O 3 which is difficult to penetrate and requires additional processing steps in forming the transducer, which effects the yield.
SUMMARY OF THE INVENTION
In order to overcome problems inherent in the prior art, it is desired to electrically isolate the coils from the pole tips thereby preventing current flow from the coils to the pole tips and subsequent discharges from the pole tips to the disk. A pre-amplifier energizes the coils in the thin film transducer and it is desired to use a non-zero bias pre-amplifier because a zero bias pre-amplifier is more complex and requires both a positive and a negative power supply. A non-zero bias pre-amplifier is therefore simpler and less costly to use. Since it is desirable to use a non-zero bias pre-amplifier, typically at 5 volts above ground, and since the pre-amplifier energizes the coils, the coils will also be at 5 volts above ground. In order to prevent current flow from the pre-amplifier to the coils and from the coils to the magnetic core and pole tips and in turn to the disk, the coil is insulated from the pole tips. It is well known that when two elements of a circuit are at the same potential there is no current flow between them. In the present invention in order to prevent the further possibility of discharge from the pole tips at pre-amplifier potential to the disk at ground potential, grounding the pole tips will prevent discharge and current flow from the pole tips to the disk.
In the present invention, the pole tips are grounded by attaching the magnetic circuit, of which the poles or pole tips are a part, to an electrical connection which is external to the transducer. The coils are spirally wound and disposed one above the other. In previous, two coil, thin film magnetic data transducers, the upper coil and the lower coil were connected at their adjacent inner ends by a coil bond pad and a conductor provided an electrical connection from the coil pad to a center bond pad. The center bond pad was connected to the amplifier or pre-amplifier. This gave a center tap connection required by previous pre-amplifiers and the poles of the magnetic circuit were not connected, that is, they were electrically isolated in the magnetic head structure. On current thin film transducers the coils are still connected together by a coil bond pad to complete the coil circuit. The center bond pad remains as part of the thin film fabrication, although not used since the current pre-amplifiers do not require it. In the preferred embodiment of the present invention, the unused center bond pad connection for the center tap is disconnected from the connection between the coils at the coil bond pad and is connected to the thin film poles of the magnetic circuit and is used to ground the poles.
In addition, there is another type of noise occurring from displacement currents which the present invention eliminates. There is a capacitance between the disk and the pole tips and another unbalanced capacitance due to processing differences between the coil and the pole tips. The pole tip to disk capacitance is variable depending on the separation between the pole tips and the disk as the disk rotates. As the transducer flies over the disk and encounters a small bump or depression on the disk the capacitance changes suddenly, causing displacement current which is a flow of charge in the circuit due to the change in capacitance with a fixed potential applied. At an AC level, the displacement currents adjust rapidly and if the circuit is changing rapidly due to bumps on the disk, noise will be introduced on the line which will be amplified to larger noise causing a problem in reading correct data from the disk due to noise generated by the imbalance between the poles and the coil. By grounding the pole tips, the pole tips and the disk are at the same potential so that there is no displacement current between the pole tips and the disk and an electrostatic shield is thereby provided.
There are, therefore, two types of electrical discharge noise encountered from the thin film magnetic transducer to the disk which are eliminated by the present invention. First, is the noise due to actual current flow between the coil and the disk via the insulator defects and the pole tips and secondly, is the noise from the capacitive coupling of the coil to the disk and the flow of displacement currents.
In the present invention, with the connection of the poles of the magnetic circuit to the center bond pad, there is also provided a test point for measuring pole to coil resistance and/or other electrical parameters, allowing the detection of a defect in the photo resist insulator and allowing the subsequent determination of whether the transducer is functioning as required prior to assembly in the disk drive. This is an important advantage in eliminating unnecessary expenses from the manufacturing process.
It is therefore an object and advantage of the present invention to provide an apparatus and method of preventing electrical discharges from the pole tips to the disk of a disk drive in order to permit the use of a non-zero bias pre-amplifier and to have the pole and disk at the same potential so as to avoid current flow between the two.
It is yet another object and advantage of the present invention to allow the grounding of the pole tips of a magnetic circuit in a thin film magnetic transducer by making only one modification of a photo mask layer and no additional processing steps.
It is another object and advantage of the present invention to avoid capacitive charge caused by displacement current that can build up between the poles and the disk.
It is still yet another object and advantage of the present invention to provide a test point for checking pole to coil resistance and/or other electrical parameters.
These and other objects and advantages of the present invention will become clear upon review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged top plan view, with the upper layer partially removed, of a thin film magnetic transducer.
FIG. 2 is an enlarged cross-sectional view of the thin film data transducer taken on line 2--2 of FIG. 1, showing the two layers of coil ad the pole tips in greater detail.
FIG. 3 is an enlarged view of FIG. 2 showing the pole tip region and coil in greater detail.
FIG. 4 is an enlarged perspective view of a thin film data transducer disposed upon a fragmentary position of a slider.
FIG. 5 is a perspective view of the load beam and flexure of the disk drive which carries the transducer.
FIG. 6 is an exploded isometric view showing major steps completed in forming the various layers that make up the transducer. FIG. 6 shows the shape of the holes in the photo mask (or negatives) used in the photolithography on the insulating layer.
FIG. 7 schematically illustrates a disk drive assembly showing the electrical connections of the magnetic circuit of the magnetic head to the disks.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in general and in particular to FIG. 1 of the drawings there is shown an enlarged plan view, with the upper layer partially removed, of a thin film transducer shown generally by the number 10. Within the transducer 10 is an upper thin film magnetic core or pole 12, having an upper pole tip 14 shown as a projection from the upper pole 12 in the upper pole tip region 16. Positioned beneath the upper magnetic core or pole 12 is a two layer coil structure comprising the coils 18 and 20. In current thin film transducer technology, a two layer coil is used between the upper pole 12 and a lower pole 22. A single layer coil could, however, be used within the spirit and scope of the invention. These coils are spirally wound and are flat. In FIG. 1, there can be seen the upper coil 18 of the two layer coil and a partial view of the lower coil 20. The transducer 10, as shown in FIG. 2, has a lower thin film magnetic core or pole 22 having a lower pole tip 24, also shown as a projection from the lower pole 22 in the lower pole tip region 26, in the same manner as the upper pole 12. In previous thin film magnetic transducers, the upper coil 18 and lower coil 22 were connected at their inner ends by a coil bond pad 19 and a conductor such as a conductor 28, FIG. 1, provided an electrical connection from the bond pad 19. This provided a coil center tap connection, required by previous pre-amplifiers. In the present invention, as seen in FIG. 2, the connection 19 between the inner ends of the upper coil 18 and lower coil 20 is maintained by the coil bond pad 19, but the conductor 28 is disconnected therefrom. The conductor 28 is now connected to either the upper pole 12 or the lower pole 22. The poles 12 and 22 are connected or joined to each other by the via connection 32 between the poles 12 and 22 at the inner ends of the coils 18 and 20. Since it is desirable to use a non-zero bias pre-amplifier, typically at 5 volts above ground to energize the coils 18 and 20, the coils 18 and 20 in the transducer 10 will also be at 5 volts above ground. In order to prevent current flow from the coils 18 and 20 to the magnetic poles 12 and 22 and to the pole tips 14 and 24, the poles 12 and 22 are insulated from the coils 18 and 20 by the insulator 34.
FIG. 2 shows an enlarged cross-sectional view of the thin film data transducer taken on line 2--2 of FIG. 1 showing the upper and lower coils 18 and 20 and the poles and pole tips in greater detail. In FIG. 2, there can be seen the upper coil 18 and the lower coil 20. These are insulated from each other and from the magnetic poles 12 and 22 by the insulating material 34 such as photoresist. The end 36 of the outermost turn of the lower coil 20 (as seen in FIG. 1) is a pad providing a point for connection to one terminal 38 (FIG. 7) of the pre-amplifier 40 and the end 42 of the outermost turn of the upper coil 18 (as seen in FIG. 1) is a pad providing a point for connection to the other terminal 44 of the pre-amplifier 40, also as seen in FIG. 7. The innermost turn 46, FIG. 2, of the lower coil 20 is connected to the innermost turn 48, FIG. 2, of the upper coil 18 at the via 50, FIG. 1, by the pad 19, FIG. 2. In FIG. 2, there is an upper pole 12 and a lower pole 22 with the turns of the upper and lower coils 18 and 20 disposed therebetween. There is, therefore, no current flow from one coil to the other through the insulation 34 except at the pad 19 at the via 50 and the magnetic circuit is closed at region 56 by joining the upper and lower poles 12 and 22 at the via 32.
In FIG. 2 there is shown the lower pole 22 with the lower pole tip region 26 and the upper pole 12 with the upper pole tip region 16. The poles 12 and 22 are typically formed of nickel iron, but may be of other suitable compositions. A gap 54 is defined between the upper pole 12 and the lower pole 22. The connected poles are then attached to one end of the electrical connection 28, FIGS. 1,4 and 7, and the electrical connection 28 is coupled at its opposite end to the disks, that is, to ground (FIG. 7). The electrical connection 28 is external to the transducer.
FIG. 3 is an enlarged view of the pole tip region of the thin film magnetic transducer. It can be seen in FIG. 3 how the coils 18 and 20 can become very close to the poles 12 and 22 in the pole tip regions 16 and 26. The coils 18 and 20 are electrically insulated by the photo-resistive material 34 which has a high electrical resistance but which may have portions with poor electrical insulating qualities because of tiny holes in the photo-resistive material or extraneous pieces of metal left on the photo-resistive material during processing which allow current to flow from the coils 18 and 20 to the poles and thence to the pole tips 14 and 24. The present invention prevents the signal noise due to electrical discharge that occurs in prior art arrangements when the pole tips 14 and 24 of the transducer come very near the surface of an adjacent disk.
FIG. 4 is an enlarged perspective view of a thin film data transducer. In the embodiment shown in FIG. 4, it can be seen that the pole connection 28 is an integral part of the upper magnetic pole 12. In an alternate embodiment, the center tap or pole connection 28 would come into direct contact with the lower magnetic pole 22. The depression 32 in the upper pole 12 engages the lower pole 22 to complete the magnetic circuit around the coils 18 and 20.
In FIG. 5, there is shown a perspective view of the load beam and flexure assembly 58 of the disk drive actuator which carries the transducer 10. The lower end 60 of the load beam and flexure assembly 58 has an attaching pad 62 for attaching the assembly 58 to an armstack of a disk drive, as is well known. Positioned on the end of the load beam and flexure assembly 58 is a slider 64 with the bond pad 30 attached on the rear face of the slider 64. Current pre-amplifiers no longer require the use of a center tap coil connection 28 at the coil bond pad 19 (see FIG. 2) so that the electrical connection, using conductor 28 in the present invention now connects the bond pad 30 to the poles 12 and 20. In FIG. 5, the transducer 10 of the present invention would only be visible microscopically, but is attached to the slider 64 at position 66.
In thin film magnetic transducer technology, the layers of the transducer are formed photolithographically. The layers of the transducer comprise insulators, and magnetic and non-magnetic metal layers. The present invention, in its preferred embodiment, is practiced by changing only two layers of the photo masks used in the photolithography. Fabrication of the transducer according to the present invention requires no photolithographic process steps in addition to those normally performed. The modification of the photo mask layer can be made to either the upper pole layer 12 or the lower pole layer 2 and, one insulator layer, which serves to disconnect the connection 28 from the coils 18 and 20, and to form an electrical connection 32 between the upper and lower poles 12 and 22 and the connection bond pad 30. Current thin film magnetic transducers have a junction such as the coil bond pad 19 connecting the inner ends of the upper coil 18 and the lower coil 20. In the present invention, the junction provided by the coil bond pad 19 of the coil layers remains but the former coil center tap connection of conductor 28 is broken. Conductor 28 is now directly connected. With the modification of the photo mask layer disconnecting the conductor 28 from the coils 18 and 20 at the coil bond pad 19, and using conductor 28 to form an electrical connection between the poles 12 and 22 and the bond pad 30, provision is made for the connection of a controlled voltage potential, such as ground, to the magnetic circuit comprising the poles 12 and 22. With the pole tips then connected to ground as is the disk 21 (FIG. 7), the pole tips 14 and 24 and the disk are at the same ground or zero voltage potential, but since the voltage potential can be controlled, the pole tips 14 and 24 and the disk could be at any chosen voltage. This modification of only two layers of the photo mask requires no additional processing steps in the manufacture of the transducer and thereby the yield of the transducer is not effected and the yield of the disk drives is improved.
FIG. 6 is an exploded isometric view showing the major processing steps for forming the various layers that make up the thin film magnetic transducer 10. FIG. 6 shows the shape of the holes in the photo mask (or negatives) used in the photolithography on the insulating layer. The holes represent the absence of insulator on the metal layers and the presence of metal. There are more layers used in forming the transducer, however, FIG. 6 is illustrative of the major steps as pertinent to the present invention. FIG. 6 will be described with the modification to the photo mask layer being made to the lower pole layer, however, it is to be understood that the modification can be made to either the upper pole layer or the lower pole layer. In making the modification to the lower pole layer 68 as shown in FIG. 6, there is an electrical connection between the lower pole 22 and the bond pad 30 of the center tap connection 28. The lower pole 22 is connected to the upper pole 12 so that both poles are electrically connected to the bond pad 30 for the center tap connection 28. In the second layer shown generally by the number 72, an insulator 74 is provided for the lower coil 20 of the third layer 76 as is currently done in the present technology. In the third layer 76, the lower coil 20 is connected to a bond pad 78 by connecting wire 80. The bond pad 78 in turn is connected to the preamplifier (not shown in FIG. 6). In the fourth layer as shown generally by the number 82, there is shown the insulator 84 to provide an opening from the lower coil 20 to connect it to the upper coil 18 at the pads 19. In the fifth layer 86, the upper coil 18 is connected to the bond pad 88 by connecting wire 90 which is also, in turn connected to the preamplifier. The coils are connected in series. In the sixth layer as shown generally by the number 92, there is shown the insulator 94 for the upper coil 18 of the fifth layer 86. The seventh layer 96 is the upper pole layer and the eighth layer 98 provides a general insulator which keeps air and contaminants away from the transducer. It can be seen therefore, that a modification has been made only to one layer of the transducer. The sequence of the various insulating layers has been changed to disconnect the center tap connection bond pad from the coils, however the design of these layers remains unchanged.
FIG. 7 illustrates the transducer 10 on a slider 64 integrated into a disk drive system. The slider 64 comprises a body having a first rail 100 and a second rail 102. Positioned on the second rail 102 is the transducer 10 shown symbolically in the form of a core or yoke 12 of magnetic material. Conductors 80 and 90 connect the ends 36 and 42 of the coils 18 and 22 to the bond pads 78 and 88, respectively, which in turn are connected to the pre-amplifier 40 by the conductors 38 and 44, respectively. The bond pads 78, 88 and 30 and the connecting wires 28, 80 and 90 appear in FIG. 6. The connecting wire 28 connects the poles 12 and 22 to the previously unused bond pad 30 for the center tap connection 28 (as shown in the first layer of FIG. 6) and then to ground 104 which grounds the pole tips 14 and 24. In the preferred embodiment of the present invention, the pole tips 14 and 24 are connected to ground as are the disks. However, it is to be appreciated that being at the same potential the pole tips and disks may be at a potential other than ground. The slider 64 is part of a disk drive and is disposed by an actuator 6 in proximity to the surface of a disk 7 mounted on a spindle 8 powered by a motor 9. The actuator 6 and the motor 9 are mounted on a disk drive frame 5. The frame 5 is usually at ground potential, but in some instances is electrically isolated from its environment and the frame 5 may be at some potential other than ground. Since the disk and the thin film poles 12 and 20 of the magnetic circuit of the transducer are connected to the frame 5 they are at frame potential, that is, there is no potential difference between them to cause arcing.
It can be seen that by connecting an ohmmeter between the bond pad 30 and either bond pad 78 or 88 in the coil circuit, a low resistance would indicate that a connection is formed, thereby detecting a pole to coil short. This would be of great advantage to a manufacturer of thin film magnetic transducers, much of the labor intensive work is performed after the transducer has been manufactured, for example, in the labor required to glue or attach the slider to the flexure, and, in fact, the assembly of the drive, so that the manufacture of the transducer only represents about twenty percent or less of the total cost of the disk drive. It would therefore be greatly advantageous to identify a defective transducer at the time of manufacture.
From the foregoing, it can be seen that there has been accomplished by the applicant's invention all of the objects and advantages of the invention. Nevertheless, variations in the structure of the invention and the arrangement of the various parts are within the spirit and scope of the applicants' invention. The embodiments given have been given only by way of illustration and the applicants are not to be limited to the embodiments shown and described. | A thin film magnetic data transducer which prevents capacitive coupling between the transducer and the disk of a disk drive system, has a magnetic circuit which is maintained at the same potential as the disk, usually ground potential. With the disk and the magnetic pole tips of the magnetic circuit at the same potential, capacitive charging and consequent current flow or arcing or discharge noise between the two are prevented. Noise from current due to the variable capacitive coupling of the coil to the disk during disk rotation is also eliminated. The thin film magnetic transducer is fabricated by depositing successive layers of an electrical insulating material, a magnetic material, insulating material, electrical conducting material for a planar coil, insulating material and magnetic material, in the order named on a substrate. The planar coil comprises spiral turns and the magnetic material layers are joined with each other within the spiral turns of the coil and encircle the coil, providing a magnetic gap between pole tips outside the of the coil. A thin film extension of the magnetic circuit is part of a circuit which connects the magnetic circuit to the frame of the disk drive as are the disks, which is usually ground potential. | 6 |
BACKGROUND OF THE INVENTION
The increasing use of digital logic in circuit assemblies and the increasing complexity of these digital logic circuits has generated a search for test techniques other than the traditional "functional test" methods that apply digital patterns to the circuit assembly inputs and compare the response from the circuit assembly outputs to expected values. These functional test input signals may be complex and difficult to specify properly since they must cause digital circuit activity to propogate from the circuit assembly inputs through various digital devices to the site of a potential fault and further cause transmission of signals from the fault site to the assembly output. One alternative technique is known as "incircuit" testing. In this technique, one applies a digital pattern directly to the device under test, and detects the output from that device in order to verify proper operation. Early implementation of such a technique using a probe is described in the September 1972 issue of the Hewlett-Packard Journal in an article entitled "Logic Pulser and Probe: a New Digital Troubleshooting Team", By Robin Adler and Jan R. Holland. The implementation of such a technique is the subject of U.S. Pat. Nos. 3,543,154; 3,641,509; 3,670,235; 3,781,689; and 3,965,468.
Further developments have occurred in the class of test equipment using this test technique. These developments include the ability to pulse more than one node or device at one time, the ability to pulse larger numbers of patterns in order to test more complex devices, the ability to handle third state data and others. Such equipment is manufactured by GenRad, Inc., Concord, Mass. The implementation of such techniques are described in U.S. Pat. Nos. 3,870,953; 4,236,246.
The implementation of the "incircuit" test technique requires application of a pattern directly to the device under test and measurement of the response from the device. Since digital logic circuits, except those at the input or output of the circuit assembly, are generally connected to other digital logic circuits, the application of the pattern requires overdriving the pattern which is applied by the "upstream" logic devices during normal device operation. Upstream logic devices are those devices whose outputs drive the inputs of the device under test.
FIG. 1 represents a prior art design. Prior art techniques of pattern application involve taking a file of generic patterns for a specific device, combining it with a topological description of the board, and applying these patterns device by device to the board under test. The design is capable of providing a sequence of patterns to the device under test for suitable periods long enough to test the individual device. Between each test, there is a delay caused by automatic tester overhead and used for the protection of devices. These fixed periods of time permit devices upstream to cool. However, several problems are apparent. First, the fixed time period between tests, unrelated to the actual time necessary for the devices upstream to cool, reduces throughput. Second, in order to test certain complex logic devices, it is necessary to first place these devices into a known state before beginning the test. This process, known as "homing", consists of applying a pattern or a short series of patterns of input signals, until the device responds with a certain predetermined pattern of output signals. When this pattern has been received, the device is in a known state or homed. However, if the device fails to home because of a defect, the homing pattern would be applied continuously until a fail safe timer in the circuit tester shuts down the hardware. The fail safe timer is designed to prevent the tester from applying a set of patterns indefinitely and is usually set for the maximum possible test time for the entire test sequence to be applied. This could be long after upstream devices have been damaged. Third, the drivers used in the prior art have no provision for the control of overshoot which increases the risk of CMOS "latch up". All of these problems and more are resolved by the methods and apparatus to be described below.
SUMMARY OF INVENTION
One of the primary concerns of the incircuit test technique is the possibility of damage to the devices which are "up-stream". Since the patterns are applied directly to the device under test, this necessitates that the outputs of the up-stream device be overdriven (FIG. 2). This may lead to damaging the device through various mechanisms including three specific damage mechanisms: CMOS "latchup", Bond Wire Fusing, and Device damage through die Heating. A discussion of these and other mechanisms appear in the Appendix.
CMOS "latchup" is a self destructive property of CMOS logic. The damage is caused by the formation of a parasitic SCR. Once the parasitic SCR has turned on, it conducts large amounts of current from Vdd to Vss which causes large power dissipation which in turn destroys the device. Vdd and Vss are voltages on the supply rails (i.e., the connections to the power supplies). Once the parasitic SCR has turned on, it will remain on until power is removed from the device or the device fails. Referring to FIG. 3, observe that the SCR is formed by the positive feedback of a NPN-PNP series transistor pair Q1-Q2. FIG. 4 shows that Q1 is the vertical NPN transistor formed by the N+ Source (emitter), the P-Tub (base) and the N-Sub (collector). Q2 is the lateral PNP formed by the P+ Source (emitter), the N-Sub (base) and the P-Tub (collector). R-Sub is the spreading resistance encountered by a current in the N-Sub material from a carrier source to a N+ contact. R-Tub is the spreading resistance encountered by a current in the P-Tub from a carrier source to a P+ contact. With either Q1 or Q2 turned on, the circuit will have positive feedback as long as the beta of the vertical transistor times the beta of the horizontal transistor is greater than unity. Note that a small current through R-Sub or R-Tub can start the positive feedback process.
CMOS "latchup" may be caused during incircuit tests by allowing a voltage, which exceeds either supply rail of the device by one diode junction potential, to be applied to the output of the upstream device or to the input of the device under test. Such voltages are caused by the driver of the test apparatus under certain conditions. FIG. 5 shows a driver which is connected to the device under test through wire of various lengths. This wire has inductance. Capacitance is present between the wires connecting the driver to the device under test. FIG. 6 illustrates that when the driver applies a low or a high signal, this inductance and capacitance can cause overshoot. If this overshoot exceeds the diode junction potential, then current will be injected into the substrate or tub causing current which will lead to CMOS "latchup".
Bond Wire fusing is caused by excessive heating of the bond wires. It can occur on a device upstream from the device under test. FIG. 7 is a schematic of the output stage of a standard TTL device. This device represents an output stage of a device upstream from a device under test. If the device is attempting to apply a "false" or logic level 0 to the device under test, and the driver is attempting to apply a "true" or logic level 1 to the device under test, there will be a large current drawn through the lower transistor of the output driver. This is a highly likely occurrence during portions of an incircuit test sequence. There may be a multiplicity of devices upstream from the device under test. If several of these devices are located in the same package, then the high currents through this package may cause damage. While the currents through the output bond wire will usually be in a safe region because only one overdrive current flows through such wire, currents through the Vcc and Vdd supply lines are additive and if more than one output of the same package is overdriven in the same direction, then the current through these supply lines will add. The large amount of currents flowing through the supply bond wire will cause resistive heating, and if this occurs for long enough, the bond wire will melt similar to a fuse. Once this occurs the device is ruined.
Devices may also be damaged through die heating. Die heating is caused in the upstream device by a process which is similar to wire bond fusing. Refering again to FIG. 7, the lower transistor in the totem pole is turned on attempting to sink current from the output until the output approximately equals the supply voltage. The transistor is normally driven into saturation and the voltage drop across the transistor is small. After the current has been switched, the current through the device is low, so that the power dissipated in the transister is low. However, when the device is being overdriven, the transistor is brought out of saturation and into the active region where the voltage across the transistor instead of being small is approximately equal to the difference between the output and supply rail. As stated above the current through the transistor is also high, thereby resulting in a large power dissipation. The ability to handle this power dissipation depends on several factors. First, how many outputs in the package that are connected to the device under test are being overdriven. Second, what type of package (for example, ceramic or plastic) is the device held in, and third, how the chip is attached to the package. The type of package and the method of attachment are often combined into a factor known as the thermal resistance. These factors are known as safeguard parameters. If the device is permitted to heat up to too high a temperature, then the output transistor will be damaged. This damage may appear immediately as a bad device at the time of test or it may appear later as significantly reduced operational lifetime of that device.
The invention represents an improved method of pattern application which permits increased throughput while decreasing the risk of damage to the device under test and to the devices upstream from the device under test.
Among the features of the invention are:
1. A method of reducing the overshoot or undershoot on inputs or outputs of a CMOS device without reducing driver voltage.
2. A method of identifying which test will potentially damage devices and preventing those tests from being executed.
3. A method of selecting an inter-test delay necessary to protect the device from damage while increasing throughput.
4. A method of preventing damage caused by homing a device which fails to home.
DRAWINGS
The invention will now be described in connection with the accompaning drawings.
FIG. 1 is a general illustration of a prior art technique.
FIG. 2 is an illustration of the effect of overdriving a node.
FIGS. 3, 4, 5 and 6 illustrate the causes of CMOS "latch-up".
FIGS. 7 and 8 illustrate the effect of overdriving an upstream device.
FIG. 9 is a block diagram of a preferred test system apparatus operating in accordance with the method of the invention.
FIG. 10 is a block diagram of a driver module which reduces the overshoot and undershoot in accordance with the apparatus described below.
DESCRIPTION OF THE INVENTION
FIG. 9 shows part of the improved test apparatus. The process of applying the patterns begins with three input files 91-93. File 91 contains a topological description of the board under test, File 92 contains a set of safeguard parameters for each of the devices on the board under test, and File 93 contains a set of pre-generated generic patterns for each of the devices under test. These files are then analyzed by a topological analyzer 94. This analyzer, among other things, sorts through the generic patterns and selects patterns which are suitable for testing the device and selects the driver module to be used with this device. These patterns, along with the topological and safeguard data are passed on to a damage analyzer 95.
Damage analyzer 95 is responsible for, among other things, the calculation of the time interval the test will require, a determination of whether the test may possibly damage upstream components, and calculation of the required variable inter-test delay times. This data, along with the safeguard parameters, is passed to a controller 96.
Controller 96 applies the patterns to a device under test 98 through a driver module 97, receives the response of device under test 98 through a sensor module 99 and compares this response to an expected response. The controller inserts the variable inter-test delays in order to protect devices upstream from damage.
Driver module 97 must be capable of overdriving the output of the upstream device. However, driver 97 must be capable of controlling overshoot in order to prevent CMOS "latchup".
In order to overdrive devices without causing damage through bond wire fusing or die overheating, the application of patterns must be analyzed in two steps. First, the test must not be so long as to cause overheating or damage. Second, the tests of two devices, one after the other, must not be so close in time as to cause the damage. In order to prevent the first type of damage, a maximum allowable test duration is determined. If the length of the test exceeds the maximum allowable test duration, then the test is flagged not to be executed. To determine the maximum allowable test duration, damage analyzer 95 examines the maximum test time for both bond wire fusing and die overheating. In order to prevent the second damage phenomenon, the minimum allowable cooling delay is calculated by damage analyzer 95 and used by test controller 96 between tests to assure that no number of test when combined will exceed the maximum allowable temperatures for the devices. Again the analysis is done for both bond wire fusing and die overheating types of damage.
The maximum overdrive duration due to bond wire overheating constraints is a function primarily of package material and the amount to overdrive current through the supply lines. This duration limit is calculated by damage analyzer 95 for each supply pin of the upstream devices. Then the minimum of these duration times is used by the damage analyzer to determine the maximum test duration. The following formula is used to calculate the delay for each supply pin:
For ceramic packages:
max time=-0.00716* ln (1-0.3865/((Np*I)/Nw)**2)
For plastic packages:
max time=-0.00129* ln (1-2.825/((Np*I)/Nw)**2)
Where:
Np=The number of device outputs being overdriven and causing current to flow through this supply pin.
I=The amount of current caused by each overdriven output.
Nw=The number of bond wires absorbing the overdrive current.
The preferred embodiment of the algorithm uses worst case analysis for Np and it estimates the Np for the upstream device to be the lesser of the number of outputs attached to the device under test inputs or the maximum number of outputs which could be functioning at a state requiring overdriving by the tester. The maximum number of outputs which could be functioning at a state requiring overdriving and the overdrive current per output for each bond wire are device dependent paramenters which are provided by file 92.
The maximum overdrive duration is also constrained by die overheating considerations. This duration is a function of the thermal resistance of the package, the power being dissipated in the output transistor, and the number of overdriven outputs in the device. The maximum duration of such a test is calculated as follows:
max time=(-Rjc/2000)* ln (1-25/(Rjc*Pw*Np))
Where:
Rjc=The junction to case thermal resistance.
Pw=The power dissipated by each overdriven output.
Np=The number of overdriven outputs on the device.
Again the preferred embodiment uses a worst case analysis. Np will be estimated for each upstream device as the number of its outputs attached to the device under test inputs. Rjc and Pw are both device dependent paramenters supplied by file 92. The maximum duration for a test is the minimum duration due to wire bond heating or due to die heating.
The device thermal analysis by damage analyzer 95 keeps track of the effects of a sequence of device tests on each overdriven device's temperature. For each device test, each of the devices it overdrives will be analyzed in turn to calculate the longest cool down delay such that each of those overdriven devices can recover from the effects of the test.
The delay may be placed either before or after the test for which the delay was calculated. However, cooling before the test offers an advantage because only the heating caused by the next test to be performed is important. If cooling is done after performing the test, then either the cooling calculation must cool for the duration required for the worst case heating or else the heating caused by the next test must be known. Use of cooling before, means the device is allowed to cool for only as long as necessary for the next test to be performed and reduces the amount of calculations necessary to keep the temperature from exceeding a certain value selected to protect the circuit. The maximum temperature permitted by the preferred embodiment for any device is 40 degrees Celsius above ambient and this assumption is reflected in the calculations below.
Two different types of cool down delays are used. The first type of cool down delay is calculated on the assumption that a test on this component has not been continuously repeated in a test program loop more than a hundred times. Furthermore, these delays are calculated assuming that die cooling, under either the first or second delay calculation, will exceed the time necessary for bond wire cooling. It is calculated using the following formula:
Temp rise=Pw*Rjc*Np*(1-e**(-2000*Ton/Rjc))
normal delay=-(Rjc/2000)* ln (1-Temp rise/40)
Where:
Pw=The instantaneous power absorbed by one device output pin being overdriven.
Np=The number of pins on the device being overdriven.
Rjc=The case/junction thermal resistance for the package class.
Ton=The time duration of pattern application.
Pw and Rjc are package dependant. Np will be estimated as the number of device outputs connected to inputs on the device under test. The parameter Ton will be calculated for each test as a function of the pattern cycle time.
The second type of cool down delay is used when a test is being continuously looped. This calculation ensures that the duty cycle will not cause the average power fed into the overdriven device to exceed its steady state capacity to dissipate power. In either case minimum delay is the tester overhead and the maximum delay is five times the package time constant. The steady state delay is calculated as follows:
steady state delay=Ton*(Pw*Np*(Rjc+100)/15-1)
Ceramic packages provide less heat dissipation for bond wires, because the bond wires are not encapsulated. For this reason the cooling time constant for ceramic packages is slow enough that bond wire cooling delay will override both the normal and steady state delays, based on die heating, discussed above. The bond wire cooling delay is never allowed to exceed 5 times the cooling time constant for ceramic packages. Again, the analysis assumes the bond wire temperature is the maximum allowed. If the current test will cause a rise in excess of 200 degrees Celcius, the maximum time constant will be used. Otherwise the following formula will be used:
Bond Temp=517.5*(I*Np)**2*(1-e**(-Ton/0.00716))
Bond Cool=-0.00716* ln (1-Bond Temp/200)
The delay calculated is in seconds.
In order to prevent damage during homing of a device having a fault which prevents it from going into a known state, the homing capability in controller 96 includes a maximum loop count. If the device never meets the exit conditions specified in the homing loop, the homing loop will execute once more after the loop count is exhausted. From the exact number of homing loops it is possible to compute the exact time of the homing sequence. Note that this is different than the fail safe timer which shuts down the hardware after a long time has gone by. The fail safe time must be set for the maximum total test time otherwise it might shut a good test off prematurely. The preferred method of homing is superior since the homing time is separate from the fail safe time and need only be as long as necessary to home the device.
In order to use the variable delays which were calculated above, the test controller must be capable of measuring the time since the last pattern is applied. These timers are activated at the end of the last test and the cool down period must pass before the next device test is started.
FIG. 10A shows a driver circuit 110 utilized in driver module 97. Driver module 97 consists of a multiplicity of identical driver circuits 110 which are assigned by topological analyzer 94 to inputs of a device under test 98. These circuits are responsible for converting the internal true, false and third state signals of a test sequence in test controller 96 to the physical voltage signals which are understood by the device under test. Driver circuit 110 also is capable of controlling the slope of the voltage signal through the use of a pair of variable current drive sources 120 and 124 under the control of controller 96 and a slope controller 119.
Drive circuit 110 utilizes a transistor 111 connected in series with a transistor 112. The emitter 113 of transistor 111 is connected at a node 114 to the emitter 115 of transistor 112. Collector 116 of transistor 111 is connected to a source 121 of voltage V pulse high and collector 117 of transistor 112 is connected to a voltage source 124 of voltage V pulse low. Driver output 118 is connected to node 114 to provide the driver output signals.
To prevent CMOS latchup, the slope of the driver output signals is limited by use of a slope controller 119 and a variable current source 120 which are connected to base 122 of transistor 111. Slope control is also effected by use of a slope controller 119 and a variable current source 124 which are connected to gate 126 of transistor 112. When controller 96 changes the current supplied by source 120, the rate of change of the voltage applied to base 122 is limited by slope control 119. In the preferred embodiment, slope control 119 is a capacitor of sufficient size to limit the slope of the driver output signal sufficiently to avoid CMOS latch-up. Similarly, the combination of slope control 119 and variable current source 124 produce a signal to base 126 of limited slope. The output state of each driver is determined by the current from sources 120 and 124. FIG. 10B shows the correspondence between driver output signal states DRIVE HIGH, DRIVE LOW and THIRD STATE and current sources 120 and 124.
When a third state driver output is desired, both current sources are off. When the controller desires to produce a high driver output it activates current source 120 to its selected level. This causes current from the variable current source 120 to flow to transistor 111 and the slope controller 119. As the slope control component begins to charge up, transistor 111 turns on and the driver output 118 follows the voltage on the slope control 119. The driver output voltage is approximately equal to the reference voltage PULSE HIGH. The slope steepness is controlled by the amount of current, and the choice of the slope controller. When controller 96 desires a low driver output, it activates current source 124 to the selected level after turning current source 120 off. This turns off the top transistor 111 and turns on the bottom transistor 112 which connects the DRIVER OUTPUT at the low driver potential thereby applying a low or false state. In the preferred embodiment the variable current sources are controlled to provide either no current or one of two non-zero currents. The larger of these two non-zero currents results in a steeper slope of driver output that can be used in testing TTL and other high current circuits. The smaller of these two non-zero currents results in a slower rate of change in the driver output signal appropriate in avoiding CMOS latch-up when a CMOS circuit is under test. The slope control component in the preferred embodiment is a capacitor.
APPENDIX
An automatic method for determining the potential for damage due to in-circuit testing can be developed using simple thermal models for the IC junction and bondwire. Device data, such as thermal resistance, overdrive current, overdrive voltage and package type are required for the analysis and can be supplied by the test programmer. Test data, such as actual test duration and number of outputs potentially overdriven simultaneously are derived from a library of tests for digital devices.
The actual test duration is calculated knowing the maximum number of test steps which could be executed during the test, and the application rate of those test steps. Then, a constraint is calculated based on the lower time given by constraining the junction to a safe temperature rise (Equation 3), and constraining the bondwire to a safe temperature rise (Equation 8). If the actual test time is greater than this temperature rise constraint, then the potential for damage exists and the test system programmer should be notified.
The actual temperature rise of the junction and bondwire can be calculated by knowing the actual duration of the test using Equations 1 and 10. A cooldown requirement can then be calculated as the longer of the cooldown constraints based on junction cooling (Equation 5) and bondwire cooling (Equation 11). Because of the nature of these equations, they allow pre-cooling the overdriven parts prior to the test. As a result, no calculations are performed at execution time, and the safe execution of the tests remains order independent.
In addition to automatically evaluating each test for potential damage, an in-circuit tester can also minimize the potential for damage by intelligently selecting fixture interface points, optimal overdrive voltages and optimum edge speeds.
If the safe constraints for voltage overshoot and undershoot, junction temperature rise and bondwire temperature rise are met, then a 1 msec in-circuit test will contribute to no more than 2 seconds of normal device lifetime. However, if any of these constraints are violated, the potential for damage and the amount of lifetime degradation increases dramatically.
THE IN-CIRCUIT TEST
Before discussing the potentially harmful effects of in-circuit testing, it will be useful to define the test technique and understand why it is popular. Digital in-circuit testing allows digital devices to be tested as though they are separated from surrounding circuitry. This electrical isolation is obtained by forcing node states required by the test onto the input nodes of the device under test and looking for an expected response at its outputs. When an input node is not in agreement with the forced state, the output of the `upstream` or driving, device must be overdriven. The amount of current required to overdrive this device is usually in excess of normal currents specified by manufacturers.
For most devices, forcing a high output state to a low state is equivalent to short-circuiting the output to ground; current flows out of the device and into the tester. When forcing a low output state to a high state, sufficient current must be supplied by the tester and backdriven into the device. The highest potential for failure as a result of overdrive current or the resulting temperature rise exists at the output stage of the overdriven device and not necessarily at the device under test. These failures will most commonly appear as bondwire failures or junction failures.
Visibility into the circuit being tested is gained through the use of a bed-of-nails fixture. This fixturing technique is a very convenient and effective way of gaining electrical access to each node in the circuit being tested. However, this fixturing interface can also lead to signal degradation. Signal degradation can compromise the quality of the in-circuit test, and potentially damage parts susceptible to voltage overshoot and undershoot. If the voltage at an input or output of a CMOS device is greater than the positive power supply voltage or less than the negative power supply voltage, the device can potentially be destroyed by CMOS latchup.
If an in-circuit test can contribute to damage in a device due to current flow, temperature rise, and voltage over/undershoot, why is it in such popular use today? There are three overriding answers to that question.
First, in-circuit testing is very effective at finding the types of faults that occur most commonly during the assembly of a printed circuit board. It is the lowest cost solution for finding solder shorts, wrongly inserted components, components damaged during the assembly process, and missing or incorrect components. In addition, in-circuit testing can also be effective at finding bad or marginal components, operational faults, and detecting process problems and trends.
The second major reason in-circuit testing is popular is the ease with which in-circuit test programs can be generated. A test program for a digital component is simply selected from a library of tests. The programmer does not have to understand the operation of the board or be able to generate stimulus that is meaningful while testing the board. In-circuit testing is highly compatible with automatic methods for test generation, and vendors of in-circuit test equipment are taking full advantage of that compatibility.
Finally, in-circuit testing is popular because it inherently produces component level diagnostic messages. If a device is isolated from surrounding circuitry through the node forcing technique, and that device fails a test of its operation, then that device is bad. Sophisticated backtracing routines are not needed for high confidence failure messages.
FAILURE MECHANISMS
Table I is a list of the failure mechanisms most likely to cause device failure or significant degradation of device lifetime during in-circuit testing. Each of these failure mechanisms is accelerated by one or more of the three failure accelerators discussed above; current, temperature and voltage.
Device damage can be broken into two categories. Lifetime degradation may occur during a test such that the device passes during testing and works properly in the final product, but fails prematurely in the customer's hands. The second type of damage is catastrophic, such that the device is damaged during testing and it will not operate properly in the product.
Each of the failure mechanisms in Table I were analyzed for their potential for both lifetime degradation and catastrophic failure during testing. The objectives of the research were to derive the worst case overdrive conditions under which the test might be executed, and under those conditions (subject to some imposed test constraints), minimize the potential for damage to devices during in-circuit testing. It was desirable to do this using device parameters readily available in manufacturer's data sheets, and to make the damage analysis automatic and flexible, anticipating its use for custom or proprietary parts.
OVERDRIVE CURRENTS
An emperical method was used to derive the worst case overdrive currents required by various logic families. Schematics of the internal circuitry of devices were analysed for worst case overdrive requirements. The results of the analysis are shown in Table II.
It is important to realize that when several outputs are being overdriven in a similar manner simultaneously, the sum of the individual overdrive currents will flow through a power supply bondwire in the device. For example, if 16 address lines on a MOS microprocessor are simultaneously overdriven from a low to a high state, up to 2.8 amps of current could be required to flow through the Vcc bondwire of the processor.
TEST CONSTRAINTS
Some constraints are imposed on the in-circuit test before the analysis of failure mechanisms is done. The junction temperature of an IC should never be allowed to exceed the manufacturer's specified maximum. Prior to a test, the junction will always be some temperature above ambient. A typical maximum ambient rating is 75° C. If the corresponding maximum junction temperature rating is 125° C., and both specifications are to be met, then the junction must be less than 50° C. above ambient. For a test environment ambient of 25° C., the junction would be less than 75° C., and a 50° C. rise is allowed before exceeding the manufacturer's specification of 125° C. Therefore, the temperature rise of the junction should be restricted to 50° C. or less during an in-circuit test.
Another constraint imposed on the test is the restriction of bondwire temperature rise. The constraint on bondwire rise is to restrict the absolute temperature to less than 40% of the lowest melting point of the various bondwire materials. Bondwires are made from one of two materials; aluminum or gold. Because of material interactions between aluminum wire and plastic encapsulants, gold wire is always used in plastic packages. Aluminum or gold wire may appear in ceramic packages, but aluminum yields the worst case thermal analysis and is always assumed to be in ceramic packages throughout this research. The melting point for gold is 1060° C., and the melting point of aluminum is 660° C. So, the bondwire temperature should be restricted to a maximum of 264° C., or about a 230° to 240° C. rise. By restricting the temperature rise to 200° C., or less, the amount of wire flexure during testing is kept to a minimum, and the wire is never in danger of melting.
LIFETIME DEGRADATION
If the constraints on bondwire and junction temperature rise are met during an in-circuit test, estimates of consumed lifetime can be empirically derived. Increasing the stress on a part as a result of current, temperature or voltage, usually results in exponentially increased degradation. This relationship is expressed for temperature accelerated failure mechanisms by the Arrhenius model, and similar models are available for current and voltage accelerated failures mechanisms.
The lifetime degradation of a part during in-circuit testing is expressed in equivalent normal lifetime consumed by operating the device at stressed levels. For example, a 1 msec in-circuit test (under the above constraints) will contribute to no more than 185 msec of device lifetime consumption as a result of electromigration failure acceleration. Table III shows the result for the other failure mechanisms under consideration. When the effects of all the failure mechanisms are considered together, a 1 msec test will contribute to no more than 750 msec of normal device lifetime for bipolar devices, and no more than 2000 msec of lifetime for MOS devices.
References 1-26 contain data used in the analysis summarized in Table III.
CATASTROPHIC DAMAGE
Bondwire failure or junction failure due to temperature rise, and CMOS device latchup due to degraded test signals are the catastrophic failures most likely to occur during in-circuit testing. The potential for damage from temperature related failures is minimized by adhering to the temperature rise constraints discussed earlier. If these constraints are exceeded by a test then the risk of device damage increases dramatically.
This article will not discuss in detail the variety of ways in which signal quality can be maintained on an in-circuit test system. However, there are three items which must be considered--overdrive levels, signal rise times, and fixturing techniques. Overdrive levels should be high enough to maintain adequate noise margins, yet also maintain a margin between the peak signal voltage and the power supply voltage. By slowing signal rise times somewhat, less overshoot will occur at the device being tested. However, fast rise times must be available when testing logic like Schottky. Finally there is a variety of fixturing techniques which can minimize signal degradation. These include: impedance matching, sufficient ground returns, driver and ground placement, and fixturing materials.
In order to detect when a test might potentially damage overdriven parts as a result of temperature rise, it is necessary to perform a thermal analysis on the device being overdriven. The thermal analysis predicts the temperature rise during the test. If this rise is greater than the constraining safe rise, derived above, then the potential for damage exists and the programmer should be notified.
MODEL DEVELOPMENT
It is convenient to model thermal problems as electrical problems using the following analogies:
Thermal resistance=Electrical resistance
Thermal capacity=Electrical capacitance
Temperature rise=Voltage
Heat flow=Current
The most accurate thermal model of an integrated circuit would be a lumped RC transmission line. A simplification of this complex model can be represented by FIG. 11. This model of FIG. 11 adequately predicts the `three-humped` curve, FIG. 12, often shown in research on thermal response of ICs. However, most of the values required for the model of FIG. 11 are not generally specified by manufacturers.
The model of FIG. 11 can be simplified further. With respect to other values in the thermal model, the junction thermal capacity (Cj) can be neglected. This thermal capacity is device specific, but for a junction 0.003 inches square by 0.00016 inches thick is about 5×10 -3 J/°C., and the thermal time constant is typically about 10×10 -6 seconds [27-28].
The package thermal capacity (Cc) can be modeled as a short circuit for pulses of short duration. Experimental evidence indicates that the thermal time constant for the package is 10 seconds or more. If the pulse duration is significantly less than 10 seconds then Cc is essentially a short circuit.
If package heating is ignored for a single pulse, and the junction thermal capacity is neglected then the thermal model becomes that shown by FIG. 13. Since the values of Rjd and Rdc cannot be determined explicitly, it is desirable to derive a proportional relationship of the two which gives the worst case thermal transfer model. A worst case model would describe the fastest way the junction could heat, and the slowest way it could cool.
Consider the case when the switch in FIG. 13 is closed and the voltage at node 1 (temperature at the junction) begins to rise. The fastest rise occurs when Rjd is small and Rdc is large. When the switch is opened, the slowest discharge also occurs when Rjd is small and Rdc is large. A worst case model exists if all of Rjc (Rjd+Rdc) is lumped into Rdc and Rjd is assumed to be zero. This yields the model shown in FIG. 14.
The model of FIG. 14 can be used to describe the behavior of a single output being overdriven assuming the package acts as a heat sink at a constant temperature during the overdrive period.
FIG. 15 shows a model of multiple output junctions being overdriven simultaneously. If there is no package heating, the model can, again, be simplified to that shown in FIG. 13 where the source is equal to the sum of the power being generated in each junction, and the junction to die* thermal resistance is Rjd/n, where n is the number of outputs being overdriven simultaneously. If this model is simplified to that shown in FIG. 14 it yields a conservative model for heat flow with multiple outputs overdriven. Since Rjd/n+Rdc (which is lumped into Rjc in the model) will always be less than the actual value of Rjc, the model is conservative. Future die shrinkages or technologies which put junctions closer together will be adequately covered by this model.
JUNCTION TEMPERATURE
Classical electrical equations can be used to describe both the heating and cooling of the junction based on the model of FIG. 14. Equation 1 can be used to calculate the junction temperature rise after time t.
Trise=P*Np*Rjc*(1-e.sup.(-t/(Rjc*Cd))) Equation 1
Where:
Trise=temperature rise at time t.
P=overdrive power per output overdriven.
Np=number of outputs overdriven.
Rjc=thermal resistance junction to die.
Cd=thermal capacity of the die.
note:
P*Np*Rjc=steady state temperature (maximum temperature rise).
Rjc*Cd=thermal time constant.
The thermal capacity of the die is not a readily available parameter, but a reasonable value can be calculated from Equation 2 assuming a worst case die size, and knowing the heat capacity and density of silicon.
Cd=Volume*Heat capacity*Density Equation 2
Equation 1 can be solved for time, and can then be used to predict the amount of time a test can last before rising the junction temperature by some given amount, Trise. This relationship is shown in Equation 3.
t=-Rjc*Cd* ln (1-Trise/(P*Np*Rjc)) Equation 3
Equation 3 can be used to predict the maximum test duration allowed to prevent heating a junction more than a predefined temperature rise, for a single test. But if the tester is looping on a test or for some other reason repetitively overdriving a device, heat can build up cumulatively. Even if a single test does not cause a temperature rise sufficient to violate the junction rise constraint, if the junction is not allowed to cool between tests, its temperature will eventually exceed the maximum specified by manufacturers.
The equation for the decay of the simple RC circuit shown in FIG. 14 is:
Tcool=To*e.sup.(-t/(Rjc*Cd)) Equation 4
Where:
Tcool=the temperature after time t.
To=the initial temperature.
The value of To could be obtained by adding the result of Equation 1 (using the actual test time for t) to the pretest temperature of the junction. Equation 4 could then be solved for time and the required time to cool to some acceptable temperature could be calculated. But this temperature must then be stored and used as the pre-test initial temperature in future heat and cool calculations. This requires that a considerable amount of data about the initial conditions of each part being overdriven are calculated and stored in real time.
A better way to calculate cool-down constraints is to assume the device is at its maximum allowed temperature rise before the test. The cool down time is then enforced prior to the test such that the junction is brought down to a temperature where the rise from the test will not allow the junction to exceed the maximum allowed temperature.
This makes the execution of the tests order independent and no initial temperatures need be calculated or stored. Required cool-down times can be precalculated before testing ever begins.
Equation 4 can be solved for time and the maximum allowed temperature substituted for To. Tcool becomes the actual temperature rise from the test calculated from Equation 1 using the catual test time for t. The actual test time is calculated knowing the maximum number of test steps in the test and the test step application rate.
t=-Rjc*Cd* ln ((Tmax-Tactual)/Tmax) Equation 5
The above equations ignore the effects of package heating. If a device is repectively overdriven, package heating can become significant. Experiments have shown that for up to 100 repetitive tests, the package will heat about 15° C. If the maximum allowed temperature rise is decreased by 15° C., then the above equations for junction heating and cooling will adequately predict maximum test durations and required cooling times for up to 100 repetitive tests. If more than 100 repetitions of a test are performed then an extended cool-down should be inserted to keep the package from rising by more than 15° C.
BONDWIRE TEMPERATURE
The two major types of wire-bonding material in use today are aluminum (usually alloyed with about 1% silicon) and gold. There are also two major package types in use--plastic and ceramic. Due to material interactions between aluminum and plastic encapsulants, gold bondwires are always used in plastic packages. Either gold or aluminum are used in ceramic packages but aluminum provides the worst case thermal analysis. Because the two packaging techniques have dramatically different thermal behavior, each type of package must be analyzed separately.
The gold bondwire in a plastic encapsulated package has two modes of heat transfer--radial conduction to the plastic encapsulant and axial conduction along the wire to the die and lead frame. If the die, lead frame and package are modeled as heat sinks at constant temperature, a simple heat transfer model can be constructed. Again, an electrical analogy can be used where heat flow is modeled by current, thermal resistance by a resistor, thermal capacity by a capacitor, and temperature rise by voltage. The heat transfer model is shown in FIG. 16. Radial conduction is modeled with Rr and axial conduction is modeled with Ra. Cw represents the thermal capacity of the wire. The current source represents the internal heat generation in the wire due to Joule heating.
The equation for temperature rise for a gold bondwire in a plastic package is given by:
T=Req*Q*(1-e.sup.(-t/(Req*Cw)) Equation 6
where:
T=temperature rise of wire.
Cw=thermal capacity of wire.
Req=equivalent resistance of Rr in parallel with Ra.
Q=internal heat generation given by:
Q=I 2*Rw Equation 7
where:
I=the current through the wire.
Rw=the resistance of the wire.
Rw will vary with temperature, so Equation 6 must be solved iteratively. Values for Ra and Rr can be derived using the methods of reference [29] pages 31-33, and 63-67 respectively.
Solving Equation 6 for time yields Equation 8. This equation predicts the maximum test duration allowed to restrict the temperature rise in the bondwire to T degrees Celsius. The equation is invalid for overdrive currents which cause the value of [1-T/(Req*Q)] to be less than zero. Such currents are below the steady state current carrying capability of the wire.
t=-Req*Cw* ln (1-T/(Req*Q)) Equation 8
The aluminum bondwire in a ceramic package has three modes of heat transfer. Heat can be transfered by radial free convection to the air in the package, axial conduction along the wire to the die and lead frame, and radial radiation into the package. If the package, lead frame and die are modeled as infinite heat sinks and air as assumed to remain at constant temperature, the heat transfer can be modeled as shown in FIG. 17. Rrh represents the radial convection thermal resistance, Ra is axial conduction thermal resistance, and Rrad is radical radiation thermal resistance.
Equation 8 can also be used to determine the maximum test duration allowed to restrict the temperature rise to T, for aluminum bondwires in a ceramic package. Req is Rrh, Ra and Rrad in parallel, Cw is the thermal capacity of the bondwire. Values for Rrh, Ra, and Rrad can be determined using the methods of reference [29] pages 237-240, 31-33, and 342 respectively.
Equations for bondwire cooling are derived in the same way as Equations 4 and 5. Steady state temperature (Tss) is given by:
Tss=Rw*Req*(I*Np) 2 Equation 9
The actual temperature rise in the wire as a result of the test is:
Tactual=Tss*(1-e.sup.(-ta/(Req*Cw))) Equation 10
And the cool-down time required prior to the test is given by Equation 11:
t=-Req*Cw* ln ((Tmax-Tactual)/Tmax) Equation 11
TABLE I______________________________________Failure Mechanisms Accelerated By______________________________________Bulk FailuresSecond Breakdown TemperatureMetallization FailuresElectromigration Temperature, CurrentCorrosion TemperatureInteraction with Other Materials TemperatureSurface Reconstruction TemperarureSi and Si/SiO.sub.2 Interface FailuresDielectric Breakdown Temperature, VoltageSurface Charge Accumulation TemperatureCharge Injection Temperature, VoltageBonding FailuresIntermetallic Growth TemperatureThermal Fatigue TemperatureChip Mount FailuresThermal Fatigue TemperatureUnique FailuresCMOS Latchup VoltageSource-Drain Punchthrough VoltageSiO.sub.2 Breakdown VoltageBondwire Failure Temperature, Current______________________________________
TABLE II______________________________________Theoretically Derived Worst Case Overdrive CurrentsValues are in mA, per pin overdriven Normal OutputFamily Iod Current Iod/Normal______________________________________TTL 272 16 17LTTL 23 4 6HTTL 529 20 26STTL 273 20 14LSTTL 270 8 34ASTTL 720 48 15ALSTTL 270 8 34CMOS 4 1 4ECL 215 40 5______________________________________ Note: For buffers, line drivers or other high current devices, the overdrive current can be larger than the values shown in this table. MOS data is not given since it varies considerably from device to device and with the value of Vdd. If Vdd is restricted to 5 Volts then no ratios of greater than 34 were observed, so LSTTL and ALSTTL show the greatest current ratios. The worst case o bserved value for MOS is 175 mA.
TABLE III______________________________________Failure Mechanism Comments______________________________________Second Breakdown Triggering temperature is well above maximum temperature experienced during properly designed in-circuit test.Electromigration A 1 ms test will contribute to no more than 185 ms of normal operation.Corrosion A 1 ms test will contribute to no more than 25.8 ms of normal operation.Interaction with Reaction rate is insignificant underOther Materials in-circuit test conditions.Intermetallic A 1 ms test will contribute to noGrowth more than 296 ms of normal operation.Surface An in-circuit test will not causeReconstruction sufficient thermal cycling for the onset of this failure mechanism.Dielectric A 1 ms test, under appropriate voltageBreakdown level constraints, will contribute to no more than 9 ms of device lifetime.Surface Charge A 1 ms in-circuit test will contributeAccumulation to no more than 1500 ms of device lifetime in MOS devices and 226 ms of lifetime in bipolar devices.Charge Injection Not significant during in-circuit test, under normal conditions.Thermal Fatigue Not a problem if temperature rise is restricted. Potential for failure varies with bondwire and package material.CMOS Latchup An appropriately designed in-circuit test will not cause CMOS latchup.Source - Drain In-circuit test voltages are not ofPunchthrough sufficient magnitude to cause this failure.SiO.sub.2 Breakdown In-circuit test voltages are not of sufficient magnitude to cause this failure.______________________________________
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[29] J. P. Holman, Heat Transfer, 4th Edition, 1976, McGraw-Hill, Inc., New York. | A method and apparatus are disclosed for reducing the likelihood of damage to digital logic devices under test or located in close electrical proximity to the device under test while attempting to locate faults in circuit assemblies using digital incircuit test techniques. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of Korean Patent Application No. 2006-0095244, filed Sep. 29, 2006, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
1. Field of the Invention
The present invention relates to an apparatus for compression-encoding a moving picture on the basis of H.264, etc., and more particularly, to an apparatus and method for compression-encoding a moving picture directed to preventing image quality deterioration while minimizing the amount of calculation performed for rate-distortion optimization (RDO).
2. Discussion of Related Art
Digital image data is used in video conferencing, high-definition televisions (HDTVs), video-on-demand (VOD) receivers, moving picture experts group (MPEG) image-supporting personal computers, video game systems, digital ground wave broadcast receivers, digital satellite broadcast receivers, cable TVs (CATVs), and so on. However, characteristics of images and conversion of an analog signal into a digital signal yield a large amount of digital image data. Thus, the digital image data is not used as is but rather is compressed by an efficient compression method.
Three main compression methods are used to compress digital image data. These are a method of reducing temporal redundancy, a method of reducing spatial redundancy, and a compression method using stochastic properties of generation codes. A representative method of reducing temporal redundancy is a motion estimation and compensation method, which is used in most moving picture compression standards such as MPEG, H.263, etc.
The motion estimation and compensation method is used to search for the portion of a previous or next reference screen that is most similar to a particular portion of a current screen, and transmit only difference components between the two portions. In the motion estimation and compensation method, the more precisely motion vectors are searched for, the less difference component data there is to transmit, thus providing a way to efficiently reduce the amount of data. However, searching for the most similar portion of the previous or next screen requires a considerably long estimation time and a large amount of calculation.
An H.264 codec performs the search using a cost function based on RDO instead of using a conventional sum of absolute difference (SAD)-based method. The cost function employed in H.264 uses a rate-distortion (RD) cost calculated by adding the number of encoded coefficients multiplied by a Lagrangian multiplier to a conventional SAD value. Here, the number of encoded coefficients is replaced with a value proportional to a quantized coefficient and then multiplied by a fixed Lagrangian multiplier to determine a compensation cost in order to perform the search.
In order to simultaneously obtain high compression efficiency and high image quality, encoding is performed in 16×16 or 8×8 large block units in conventional moving picture encoding, but a mode having the lowest value among eight different block modes is selected in H.264 moving picture encoding.
However, in order to determine eight different block modes, various encoding operations as well as integer-pixel and sub-pixel searches all must be performed separately for each mode. Consequently, more calculations are required and more time is taken in comparison with a conventional moving picture encoding algorithm. In order to embody a moving picture encoding apparatus for an Internet protocol (IP)-TV, it is necessary to be able to reduce calculation time by minimizing calculations for determining a block mode without deteriorating image quality.
FIG. 1 is a block diagram showing the constitution of a general H.264 moving picture encoder. Among the blocks, a motion estimator comprises an integer-pixel estimator for estimating an integer-pixel-specific motion vector, and a sub-pixel estimator for estimating optimum half-pixel and quarter-pixel-specific motion vectors on the basis of the estimated integer-pixel-specific motion vector.
The illustrated conventional H.264 encoder comprises a motion estimation (ME) module 22 , a motion compensation (MC) module 24 , an intra mode estimation (IME) module 32 , an intra prediction (IP) module 34 , a de-quantization (IQ) module 58 , an inverse discrete cosine transform (IDCT) module 56 , an entropy encoding module 64 , a deblocking filter 92 , frame memories 12 , 14 and 18 , and so on.
The motion estimation module 22 performs a function of detecting a motion vector from several reference images and a macroblock mode determination function of searching for the optimum macroblock type having the minimum bit rate and errors. The motion compensation module 24 functions to obtain a compensation image from a reference image according to the motion vector and macroblock mode type detected by the motion estimation module 22 . In FIG. 1 , the motion compensation module 24 is limited to obtaining differences between two compared images, and the following process for obtaining a compensation image is resumed by a discrete cosine transform (DCT) block 52 and a quantization module 54 .
In intra-coding of a macroblock, the intra mode estimation module 32 functions to select the optimum intra prediction mode by performing prediction on adjacent blocks. The intra prediction module 34 functions to obtain an intra-predicted compensation image from previously coded adjacent blocks using the selected intra prediction mode. The intra mode estimation module 32 performs a similar function to the motion estimation module 22 in inter mode and thus is referred to as a motion estimation module in intra mode. And, the intra prediction module 34 performs a similar function to the motion compensation module 24 in inter mode and thus is referred to as a motion compensation module in intra mode.
The DCT module 52 perfumes 4×4 DCT, the quantization module 54 quantizes coefficients transformed by the DCT 52 , and the IDCT module 56 and the dequantization module 58 respectively perform the reverse of operations performed by the DCT module 52 and the quantization module 54 .
The operation result Dn′ of the IDCT module 56 is restored images that have not passed through the deblocking filter 92 . The entropy encoding module 64 performs entropy coding using bit allocation based on the probability of the occurrence of quantized DCT coefficients. The deblocking filter module 92 functions to improve the quality of the restored images obtained through the IDCT module 56 , and the improved-quality images are stored in the frame memory module 18 to be used as references for subsequently input images.
Unlike conventional MPEG-1, MPEG-2 and MPEG-4 standards, the H.264 standard has several reference images, and a plurality of previously encoded images as well as an immediately previous frame can be used as the reference images. This is called multiple reference frames.
Similar to the conventional MPEG standards, the H.264 standard performs encoding in slices including an I_slice, a P_slice, a B_slice, an SI_slice and an SP slice. For convenience of description, a slice can be regarded as a single frame. That is, the I_slice, the P_slice and the B_slice are almost the same as an I_picture, a P_picture and a B_picture of the conventional MPEG standards.
The H.264 standard defines an inter mode representing each macroblock making up currently input frame data by a moving vector and difference value with respect to previous frame data, and an intra mode representing each macroblock by a moving vector and a difference value with respect to the same frame data. According to macroblock size, P16×16, P16×8, P8×16, P8×8, P8×4, P4×8 and P4×4 modes exist in the inter mode, and I16×16 and I4×4 modes exist in the intra mode. An H.264 encoding apparatus selects a mode providing high compression efficiency due to a low cost.
Here, the method of selecting an optimal block mode is an RDO technique. A motion estimation and mode decision algorithm using RDO can improve a bit rate by 5 to 10% at a cost of 30 to 40% encoding speed.
Therefore, in general, the H.264 standard performs motion estimation and compensation for all the modes in the sequence illustrated in FIG. 2 (alternatively, an I16×16 mode may be processed after B-slice check), calculates compensation costs, and compares the calculated compensation costs to determine an optimum mode for received frame data.
FIG. 3 is a conceptual diagram illustrating an encoding process performed by an H.264 moving picture encoding apparatus using conventional RDO. All the blocks illustrated in FIG. 3 can be embodied as separate pieces of hardware, but this increases hardware load. Generally, at least two of blocks 1200 to 1700 for mode decision are embodied as sequential operations of one piece of hardware. In this sense, FIG. 3 is merely a conceptual diagram. In FIG. 3 , a motion estimation block and a motion compensation block may have structures shown in FIGS. 4 and 5 , and an encoding block 1100 may have the structure of the H.264 encoder shown in FIG. 1 .
In FIG. 3 , a B_slice check block 1200 is directed to calculating an estimation value in a skip mode processing a previous frame and a next frame by division blocks having the zero vector for a moving vector. Three inter mode prediction blocks 1300 , 1400 and 1500 respectively operating according to P16×16, P16×8/P8×16 and P8×8 or less modes are directed to calculating inter mode-specific prediction bit values from the continuous parts of a moving picture. Two intra prediction blocks 1600 and 1700 respectively operating according to I16×16 and I4×4 modes are directed to calculating intra mode-specific prediction bit values from the non-continuous parts of a moving picture. Alternatively, the P8×8 mode may be further classified into P8×8, P8×4, P4×8 and P4×4 modes to be processed.
As illustrated in FIG. 3 , in the moving picture encoding apparatus according to conventional art, with respect to input frame data, the 6 prediction bit calculators 1200 to 1700 calculate prediction bit values for 7 modes, respectively (the 16×8/8×16 mode integer-predictor calculates two prediction bit values for 16×8 and 8×16 modes).
A mode decision block 1900 examines the 7 prediction bit values and selects the most appropriate mode, and the final encoding block 1100 converts input frame data according to the determined mode.
It can be seen in FIGS. 3 to 5 that when the standard H.264 moving picture encoding apparatus shown in FIG. 1 uses RDO, RDO is substantially performed once per block mode. In addition, in motion estimation with respect to 5 reference images, RDO must be performed once per reference image, thus significantly increasing the amount of calculation for moving picture encoding.
When each block is embodied as a separate hardware module, hardware cost goes up. On the other hand, when the blocks are embodied in one hardware module for prediction value calculation, the hardware module performs predicted value calculation 8 times (once for each of the 7 modes and once for a determined mode). Consequently, it can be seen that the amount of calculation for moving picture encoding is considerably large.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method for compression-encoding a moving picture, capable of minimizing the amount of calculation while efficiently performing rate-distortion optimization (RDO) during moving picture compression-encoding operation.
One aspect of the present invention provides an apparatus for compression-encoding a moving picture, comprising: a B-slice checker for performing a B-slice check for current frame data; a maximum inter mode prediction bit calculator for performing motion estimation and motion compensation for an inter mode using the maximum division block and calculating a prediction bit value; a minimum intra mode prediction bit calculator for performing motion estimation and motion compensation for an intra mode using the minimum division block and calculating a prediction bit value; a linear prediction bit estimator for calculating prediction bit values for modes other than the inter mode using the maximum division block and the intra mode using the minimum division block, using linear parameters and stochastic values; a mode determiner for comparing the prediction bit values calculated by the maximum inter mode prediction bit calculator, the minimum intra mode prediction bit calculator and the linear prediction bit estimator, and determining an appropriate encoding mode; and an encoder for encoding the current frame data in the mode determined by the mode determiner.
Another aspect of the present invention provides a method of compression-encoding a moving picture, comprising the steps of: (a) performing a B-slice check for input current frame data; (b) performing motion estimation and motion compensation for an inter mode using the maximum division block, and calculating a prediction bit value; (c) performing motion estimation for inter modes other than the mode using the maximum division block and intra modes other than a mode using the minimum division block; (d) applying linear parameters to the motion estimation result of step (c) and calculating mode-specific prediction bit values; (f) performing motion estimation and motion compensation for the intra mode using the minimum division block and calculating a linear prediction bit value; (g) comparing the linear prediction bit values with each other and determining the optimum mode; and (h) encoding the current frame data in the determined optimum mode.
Thus far, in order to perform RDO, a motion estimation (ME) process and a motion compensation (MC) process have been performed for all the selectable block modes, thus requiring a large amount of calculation and a lengthy calculation time.
In contrast, the present invention includes a separate rate-distortion (RD) estimator capable of easily estimating an RD value by calculation employing a linear parameter which is updated in real time through a feedback process.
When such a method is used, a motion compensation process is unnecessary in a compensation cost calculation process for most block modes other than an inter mode of the maximum division block and an intra mode of the minimum division block. Consequently, it is possible to remarkably reduce the amount of calculation.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 is a block diagram showing the constitution of a general H.264 encoder;
FIG. 2 is a flowchart showing the sequence of determining mode-specific prediction values according to a general H.264 moving picture encoding method;
FIG. 3 is a conceptual diagram illustrating an H.264 moving picture compression-encoding method according to conventional art;
FIG. 4 is a block diagram showing the detailed constitution of a motion estimator among the components of a general H.264 moving picture compression-en-coding apparatus;
FIG. 5 is a block diagram showing the detailed constitution of a motion compensator among the components of a general H.264 moving picture compression-encoding apparatus;
FIG. 6 is a block diagram showing the constitution of an H.264 moving picture compression-encoding apparatus according to an exemplary embodiment of the present invention; and
FIG. 7 is a block diagram showing the constitution of a linear feedback calculator among the components of the H.264 moving picture compression-encoding apparatus of FIG. 6 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Hereinafter, exemplary embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. The following embodiments are described in order for this disclosure to be complete and enabling of practice of the present invention by those of ordinary skill in the art.
In this exemplary embodiment, an H.264 encoding apparatus employing a feedback structure for fast encoding according to the present invention will be described in detail. Therefore, in this exemplary embodiment conforming to the H.264 standard, an inter mode of the maximum division block is a P16×16 mode, an intra mode of the minimum division block is an I4×4 mode, and a compensation cost is a rate-distortion (RD) value.
FIG. 6 illustrates the constitution of an H.264 moving picture compression-encoding apparatus according to an exemplary embodiment of the present invention. The moving picture compression-encoding apparatus of this exemplary embodiment comprises a B-slice checker 200 , a maximum inter mode prediction bit calculator 300 , a minimum intra mode prediction bit calculator 500 , a linear prediction bit estimator 400 , a mode determiner 600 , and an H.264 encoder 100 . The B-slice checker 200 performs a B-slice check for current frame data. The maximum inter mode prediction bit calculator 300 performs motion estimation (ME) and motion compensation (MC) for a P16×16 mode and calculates a prediction bit value. The minimum intra mode prediction bit calculator 500 performs estimation and compensation for pixels in the same frame in an I4×4 mode and calculates a compensation cost. The linear prediction bit estimator 400 calculates prediction bit values with respect to modes other than the P16×16 mode and the I4×4 mode using linear parameters and stochastic values. The mode determiner 600 compares prediction bit values Y 0 to Y 6 calculated by the maximum inter mode prediction bit calculator 300 , the minimum intra mode prediction bit calculator 500 and the linear prediction bit estimator 400 , and determines an appropriate encoding mode. The H.264 encoder 100 encodes the current frame data in the mode determined by the mode determiner 600 .
The B-slice checker 200 may be a conventional kind, but, in order to reduce hardware load, may calculate the prediction bit value Y 0 by performing a B-slice check for only luminance component data.
Likewise, the maximum inter mode prediction bit calculator 300 and the minimum intra mode prediction bit calculator 500 may be the same as in the conventional art, but, in order to reduce the hardware load, may perform motion estimation, motion compensation and compensation cost calculation for only luminance component data. In this case, the maximum inter mode prediction bit calculator 300 and the minimum intra mode prediction bit calculator 500 may comprise luminance motion estimators 310 and 510 , luminance motion compensators 320 and 520 , and writers 350 and 550 , respectively. Here, the writers 350 and 550 output not an encoding sequence but the linear prediction values Y 1 and Y 6 only, unlike a writer 150 of the encoder 100 .
The linear prediction bit estimator 400 comprises a first motion estimator 411 , a first stochastic value calculator 471 , a second motion estimator 412 , a second stochastic value calculator 472 , a third motion estimator 413 , a third stochastic value calculator 473 , and a linear feedback calculator 460 . The first motion estimator 411 performs motion estimation for an inter I6×8 mode. The first stochastic value calculator 471 calculates a stochastic vector (E dY2 , E dUV2 , σ dY2 , σ dUV2 ) required for linear prediction value estimation using values obtained by the first motion estimator 411 . The second motion estimator 412 performs motion estimation for an inter 8×16 mode. The second stochastic value calculator 472 calculates a stochastic vector (E dY3 , E dUV3 , σ dY3 , σ dUV3 ) required for linear prediction value estimation using values obtained by the second motion estimator 412 . The third motion estimator 413 performs motion estimation for inter 8×8 or less modes. The third stochastic value calculator 473 calculates a stochastic vector (E dY4 , E dUV4 , σ dY4 , σ dUV4 ) required for linear prediction value estimation using values obtained by the third motion estimator 413 . The linear feedback calculator 460 respectively applies linear parameters to four stochastic vectors (E dY2 , E dUV2 , σ dY2 , σ dUV2 ), (E dY3 , E dUV3 , σ dY3 , σ dUV3 ), (E dY4 , E dUV4 , σ dY4 , σ dUV4 ) and (E dY5 , E dUV5 , σ dY5 , σ dUV5 ) and calculates linear prediction values according to Formula 1 given below.
As illustrated in FIG. 7 , the linear feedback calculator 460 comprises a linear calculator 462 , a subtracter 466 , a parameter updater 464 , and a parameter storage 468 . The linear calculator 462 calculates a linear prediction bit value Y using a linear parameter P, the average and variance of luminance errors, and the average and variance of chrominance errors (X=(E dY , E dUV , σ dY , σ dUV )). The subtracter 466 calculates an error E ε between the calculated linear prediction bit value Y and an actual linear prediction bit value Y r output from the encoder 100 of FIG. 6 . The parameter updater 464 calculates an update value of the linear parameter using the error E ε between the linear prediction bit values. The parameter storage 468 stores the updated parameter .
Meanwhile, it is illustrated in FIG. 6 that stochastic value calculators 471 to 474 are respectively prepared for the modes. However, since the calculation is rather simple, stochastic vectors with respect to 4 modes may be calculated in sequence by one stochastic value calculator. On the other hand, the linear feedback calculator 460 is illustrated as one module in FIG. 6 but may also be embodied as several modules separately prepared for each mode.
The mode determiner 600 receives the 7 linear prediction values Y 0 to Y 6 , applies each of them to Formula 4 given below to calculate an RD value, and selects a mode having the minimum cost (RD value).
An encoding method performed by the moving picture compression-encoding apparatus constituted as described above according to this embodiment comprises the steps of: (a) performing a B-slice check for input current frame data; (b) performing motion estimation and motion compensation for an inter mode (P16×16 in H.264) using the maximum division block, and calculating a prediction bit value; (c) performing motion estimation for inter modes other than the mode using the maximum division block and intra modes other than a mode using the minimum division block; (d) applying linear parameters to the motion estimation result of step (c) and calculating mode-specific prediction bit values; (f) performing motion estimation and motion compensation for the intra mode (I4×4 in H.264) using the minimum division block and calculating a linear prediction bit value; (g) comparing the linear prediction bit values with each other and determining the optimum mode; and (h) encoding the current frame data in the determined optimum mode.
Step (a) is performed by the B-slice checker 200 of FIG. 6 . Step (a) may be performed according to conventional art, but, in order to further reduce the amount of calculation, may be implemented to perform a B-slice check for only luminance component data among the current frame data.
Step (b) is performed by the maximum inter mode prediction bit calculator 300 of FIG. 6 . In step (b), motion estimation is performed, and the corresponding macroblock data is discrete cosine transform (DCT)-converted and quantized according to a motion estimation value. In order to further reduce the amount of calculation, a compensation cost with respect to the inter mode using the maximum division block may be calculated by performing motion estimation and motion compensation only for a luminance frame formed according to luminance component pixel values and not for a chrominance frame formed according to chrominance component pixel values.
Steps (c) to (g) are main parts of the present invention performed by the linear prediction bit estimator 400 of FIG. 6 . In step (c), motion estimation between a reference frame and a current frame is performed for each inter mode (16×8, 8×16, 8×8, 8×4, 4×8, 4×4 in H.264), and motion estimation between pixel values in the same frame is performed for each intra mode (16×16 in H.264).
Step (d) comprises the sub-steps of (d1) calculating mode-specific averages and variances of luminance errors and mode-specific averages and variances of chrominance errors from mode-specific motion estimation results of step (c), and (d2) calculating mode-specific linear prediction bit values using mode-specific linear parameters, the mode-specific averages and variances of luminance errors, and the mode-specific averages and variances of chrominance errors.
In step (d2), the mode-specific prediction bit values are calculated by Formula 1 given below. In step (g), the mode-specific prediction bit values calculated in step (d2) are applied to Formula 2 given below so that mode-specific prediction bit values of step (c) may be calculated.
Step (f) is performed by the minimum intra mode prediction bit calculator 500 of FIG. 6 . Step (f) may be performed according to conventional art, but, in order to further reduce the amount of calculation, motion estimation and motion compensation between the pixel values of the same frame may be performed only for a luminance frame formed according to luminance component pixel values and not for a chrominance frame formed according to chrominance component pixel values, to calculate a prediction bit value for the intra mode using the minimum division block.
Alternatively, the step of updating the linear parameters may be further included. The update of a linear parameter may be made in macroblock units for which steps (c) to (g) are performed once. However, since it is preferable that the same linear parameter is applied while one frame is being processed, it is better to update the linear parameter after processing one frame.
Lastly, operation of the linear feedback calculator 460 , which is an important part of the present invention, will be described in detail below.
In order to calculate an RD value as described above, the linear, feedback calculator 460 must estimate block-specific prediction bit values very accurately.
The linear feedback calculator 460 uses as an input a DCT value obtained during a motion compensation process, or the average and variance of errors which are information corresponding to the DCT value, and so on. The linear feedback calculator 460 stores parameters corresponding to the input value and calculates a prediction bit value by linearly or non-linearly combining the input value with a stored linear parameter.
When the estimation is continued while a parameter is being corrected by taking an error between the calculated prediction bit value and an actual prediction bit value as a parameter compensation value, it is possible to estimate a prediction bit value having a minimum error. FIG. 7 is a conceptual diagram illustrating such an operation. In FIG. 7 , an input is the averages and variances of block errors in luminance and chrominance components, a parameter is denoted by a value corresponding to the input, an input stochastic vector is denoted by X, and a linear parameter vector is denoted by P.
The principal of operation of the linear feedback calculator 460 will be described in detail with reference to formulas and input examples.
The motion estimators 411 to 414 in the linear prediction bit estimator 400 calculate errors (errors between blocks) between pixels of macroblocks divided from the current frame data and pixels of a window region defined by the moving vector of the current frame.
When a luminance component is denoted by Y and a chrominance component is denoted by UV, the average of inter-block errors of luminance components calculated by the stochastic value calculator 471 to 474 is E dY , and the average of errors of chrominance components is E dUV . In addition, a inter-block variance of luminance components is denoted by σ dY , a variance of chrominance components is denoted by σ dUV , an input vector having them as its components is X=(E dY , E dUV , σ dY , σ dUV ), and a parameter vector corresponding to the input vector is P=(P 1 , P 2 , P 3 , P 4 ).
Here, parameters are classified according to block modes, thereby obtaining 6 parameter sets of P16×16, P16×8, P8×16, P8×8, I16×16 and I4×4. Thus, a parameter is presented in a 6×4 matrix form. When the P16×6 mode is given as the optimum block mode, an input vector with respect to the mode is X=(E dY , E dUV , σ dY , σ dUV ), a parameter is P=(P 1 , P 2 , P 3 , P 4 ), and a fixed value corresponding to the header information of the corresponding block mode is b, the linear prediction bit value Y is defined by Formula 1.
Y=X·P T +b Formula 1
In Formula 1, Y denotes a linear prediction value of a rate value for RD value calculation. When a rate value actually obtained by the motion compensation process is denoted by Y R , an error value E ε is defined by Formula 2.
E ε =Y R −Y Formula 2
It is an object to adjust a parameter to minimize the error value E ε defined by Formula 2. Thus, when a target function is set to E ε 2 , a parameter is updated by calculating the parameter in the steepest descent direction according to Formula 3.
P
^
=
P
-
t
·
∂
E
ɛ
2
∂
P
Formula
3
In Formula 3, t is an adaptive gain calculated according to the stochastic Armijo's rule. The updated parameter {circumflex over (P)} is substituted by P in the next part and used as a parameter for the next input to predict a rate value.
The linear prediction value of the rate value obtained by the process is used to calculate an RD value according to Formula 4.
RD=SAD+λY n Formula 4
An initial linear prediction bit estimation operation for the current frame data is performed by applying an initial value to the linear parameter P. For example, initial values may be the same fixed value of about 20, any values between 10 and 20, or determined by referring to previous encoding results.
As described above, when a Lagrangian Multiplier λ is formed using the linearly estimated rate value Y and a previously calculated sum of absolute difference (SAD) or sum of squared difference (SSD) value, a desired RD value is obtained. Here, the coefficient λ is for translating the bits (or rate R) which is generated from encoding, to the domain of the distortion D. Thus, it is possible to perform RDO without directly performing motion compensation, so that the amount of H.264 encoding calculation can be remarkably reduced.
According to the apparatus and method for compression-encoding a moving picture described above, it is possible to minimize the amount of calculation while efficiently performing RDO in moving picture compression-encoding operation.
While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | Provided are an apparatus and method for compression-encoding a moving picture at high speed while minimizing image quality deterioration. In H.264 moving picture encoding, the apparatus and method perform rate-distortion optimization (RDO) indispensable for high-definition encoding by feedback prediction, and minimize the amount of discrete cosine transform (DCT)-inverse DCT (IDCT) calculation performed for RDO many times, thereby performing H.264 encoding at high speed. | 7 |
This application is a division of application Ser. No. 270,977 filed Nov. 14, 1988, now U.S. Pat. No. 4,916,206.
FIELD OF THE INVENTION
This invention relates generally to energetic binders, and, more specifically, to a class of nitramine-containing homopolymers and co-polymers characterized by favorable viscosity and glass transition temperature.
BACKGROUND OF THE INVENTION
Certain energetic binders which are useful in propellants and explosives formulations are known in the art. By way of illustration, a compound called GAP (glycidyl azide polymer) is known to provide energy and function as a binder when formulated in propellants and explosives used in various applications. However, materials such as GAP are very expensive, costing up to $100 per pound and are known to release gases during storage and/or prior to or during processing. In addition, toxic and explosive ingredients are required to produce this polymer. Therefore, alternate high energy binders that are less expensive and safer to produce and still afford a good combination of desirable characteristics, such as a high impetus, a low glass transition temperature, and a low viscosity, would be highly desired by the propellant and explosives community.
Various nitropolymers have been fabricated in the past for application in solid, smokeless propellants. For example, Aerojet General published a report, Report No. 1162, dated Sept. 28, 1956, entitled "Research in Nitropolymers and Their Application to Solid Smokeless Propellants". This report documents various polymerization reactions useful in making nitropolymers, including various esters of nitramino diacids. These polymers, however, generally have a higher molecular weight than might be desired and do not possess carefully controlled, reactive, functional end groups as would be desirable.
Hercules Incorporated investigated a specific nitramine-containing polymer, poly(diethylene glycol-4,7-nitrazadecanedioate) designated as P-DEND. In a report entitled "High Performance Minimum Smoke Propellants", Technical Report CR-RD-PR-86-4, dated May, 1986. Hercules documents work performed for the U.S. Army Missile Command wherein P-DEND is described as being a feasible ingredient for use in nitrate ester-plasticide propellants. This report states that attempts to fabricate P-DEND by an acid catalyzed esterification reaction of 4,7-dinitrazadecanedioic acid (DNDA) with diethylene glycol in a variety of organic solvents were unsuccessful. This failure is attributed in the report to the fact that a cyclization reaction rather than a polymerization reaction occurred. More recently, the present inventors have found that P-DEND has a viscosity and a glass transition temperature that are higher than might be desired.
New polymer binders exhibiting excellent impetus and characterized by an advantageous viscosity and glass transition temperature would be highly desirable to the propellants and explosives community.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to novel nitramine-containing polymers characterized by an advantageous combination of a low viscosity and a low glass transition temperature. The novel polymers are characterized by the following empirical structural formula:
[(OOCCH.sub.2 CH.sub.2 --R--CH.sub.2 CH.sub.2 CO).sub.x (OOCCH.sub.2 CH.sub.2 --R'--CH.sub.2 CH.sub.2 CO).sub.y (OR")].sub.n
wherein R and R' are the same or different moieties selected from the group consisting of --N(NO 2 )--, --N(NO 2 )CH 2 CH 2 N(NO 2 )--, and --N(NO 2 )ZN(NO 2 )--, wherein Z is a linear or branched-chain hydrocarbon having between 3 and 10 carbon atoms, with the proviso that at least one R or R' moiety on average per molecule of said polymer must be other than --N(NO 2 )CH 2 CH 2 N(NO 2 )--, and wherein x represents a mole fraction having a value between 0 and 1, y represents a mole fraction equal to 1 minus x and having a value between 0 and 1, R" is a linear or branched chain alkylene or alkylene ether radical having between 2 and 12 (preferably between 2 and 6) carbon atoms and having primary or secondary carbon atoms at said radical's points of attachment in said polymer, and n has a value between 2 and 50 (preferably between 2 and 20).
In another aspect, the present invention relates to a process for producing a nitramine-containing polymer which comprises the steps of reacting a nitramine-containing dicarboxylic acid monomer with a diol monomer in the presence of an acid catalyst by a melt polymerization reaction to form said nitramine-containing polymer while removing by-product water during the course of said reaction.
After the reaction has begun and particularly during the later stage of the reaction, it is preferred that water be removed by vacuum distillation or as the azeotropic reaction progress in order to expedite formation of the desired nitramine-containing polymer product. In addition, it is preferred that the polymer product be purified in a purification step, suitably by precipitation in a solvent/non-solvent mixture or by using gel permeation chromatography. If desired, the nitramine-containing polymer is end-capped with a functional moiety to impart a desired terminal functionality to the polymer. In the absence of such end-capping, the polymer is generally carboxyl- or hydroxyl-terminated.
DETAILED DESCRIPTION OF THE INVENTION
The polymers described in this invention are any of a variety described by the general empirical formula given above. The polymers are prepared by reacting a nitramine-containing (i.e. nitraza-containing) dicarboxylic acid with a diol in the presence of an acid catalyst under melt polymerization (esterification) reaction conditions (i.e. In the absence of a solvent).
The monomers useful in the present invention include the following diacid (dicarboxylic) monomers: 4,7-dinitraza-1,10-decanedioic acid (DNDA); 5-methyl-4,7-dinitraza-1,10-decanedioic acid (MDNDA); 4-nitraza-1,7-heptanedioic acid (NHDA); 4,8-dinitraza-1,11-undecanedioic acid (DNUDA), and other diacids of similar structure. Useful diol monomers include a wide variety of diols, such as, for example, ethylene glycol, propylene glycol, 1,4-butane diol, 1,6-hexane diol, diethylene glycol and various other diols of similar structure.
The homopolymers identified in Table 1 below as Polymer 5 and Polymer 8 are preferred due to their relatively low glass transition temperature which provides superior performance in formulated products, such as propellants or explosives. In addition, these two polymers were found to have relatively low viscosities which gives superior performance during processing of the formulated propellant or explosive product. Other preferred polymers are those identified as Polymers 7, 9, 10, and 11 in Table 1 below. These co-polymers also possess relatively low viscosity and glass transition temperatures. It is preferred that the amount of the more rigid diacid monomer 4,7-dinitraza-1,10-decanedioic acid, be kept fairly low relative to the diol monomer used to fabricate these co-polymers, as is illustrated by the fabrication of Polymers 7 and 11.
It has been found, by virtue of the synthesis and characterization of various polymer structures leading up to the present invention, that certain polymer structures provide products having lower glass transition temperatures (See Table 1 below) and lower viscosities than those provided by prior art polymers. Specifically, Polymers 5 and 8 have lower T g 's and lower viscosities than the other homopolymer materials fabricated, including the prior art polymer P-DEND (Polymer 1). It is believed that these results are due to certain structural characteristics of the polymer molecule. Polymer 1 has two methylene groups between the nearest neighboring nitraza groups and exhibits a high glass transition temperature (0° C.) and a high viscosity. Although not wishing to be bound by any particular theory, the present inventors speculate that this result is due to a steric hinderance or polar interaction between the nitraza groups which inhibits rotation within the molecule about the molecular axis. Such interaction leads to higher glass transition temperatures and viscosities. Note that Polymer 2 has a methyl group attached to one of the two methylene groups between the nitraza groups. The fact that Polymer 2 has been found by the present inventors to have a glass transition temperature even higher than that of Polymer 1 supports the above-discussed steric hinderance theory.
The present inventors theorize that the larger spacing between the sterically bulky and polarized nitraza groups, such as the three methylene groups in Polymer 8, provides a resulting polymer having a lower glass transition temperature and lower viscosity. The glass transition temperature as indicated in Table 1 for Polymer 8 is much lower than that for Polymer 1 or Polymer 2.
Although exact viscosity measurements for these polymers has not been made due to sample size limitations, empirical measurements indicate Polymer 8 is less viscous than Polymer 1. This may due in part to the molecular weight differences between the two polymers, but even when a variety of higher molecular weight (as indicated by GPC) samples of Polymer 8 were prepared, the viscosity was found to be significantly lower than that of Polymer 1.
The glass transition temperature (See Table 1 below) and the viscosity of Polymer 5 are also much lower than those of Polymers 1 and 2. As was the case for Polymer 8, it is believed that this, again, is due to a lack of steric or polar interaction along the polymer backbone. Since Polymer 5 has an isolated nitraza group in its structure, the types of interactions along the molecular axis that result in hindered rotation should not occur.
As can be seen from Table 1, various co-polymers can be prepared by using a blend of two or more diacids. Polymers 7 and 11 were prepared using 30 percent 4,7-dinitraza-1,10-decanedioic acid ("DNDA") which has a slightly higher energy content on a weight basis than the diacid monomers used for the preparation of Polymers 5 and 8, but, as mentioned above, provides higher Tg's and viscosities for the resulting co-polymers than were obtained for the homopolymers. Fortunately, the glass transition temperatures for the resulting co-polymers prepared using a 30 percent DNDA level are acceptable. Moreover, the DNDA provides enhanced calculated energy content for the polymer. Polymer 6 which contains 70 percent 4,7-dinitraza-1,10-decanedioic acid, does show a higher Tg than Polymer 5. Thus, if a large amount of 4,7-dinitraza-1,10-decanedioic acid is used as monomer, the properties of the binder tend to have less desirable characteristics analogous to those of homopolymers of 4,7-dinitraza-1,10-decanedioic acid (P-DEND).
The polymers and co-polymers of the present invention combine the advantages cited above with high calculated (by the Naval Weapons Center PEP method) impetus in propellant formulations, a desired fuctionality of very near two, primarily hydroxyl termination (if desired) of the polymer chains, and a molecular weight which can readily be controlled to any desired value. The preferred polymer molecular weight is between about 500 and about 10,000.
Note that the molecular weight of the polymers can be controlled by varying the stoichiometry of the diol and diacid monomers. Typically, the polymers are prepared using an excess of the diol monomer relative to the diacid, thereby providing a hydroxy-terminated polymer. Alternately, the polymer may be terminated by carboxyl groups by the simple technique of adjusting the stoichiometric ratio of monomers such that the diacid (i.e. the dicarboxylic acid monomer) is present in excess relative to the diol monomer. As another alternative, other functional moieties can be used to end-cap the polymer molecules to impart a desired terminal functionality to the polymer. For example, the hydroxy-terminated polymer can be reacted with an excess of diisocyanate to yield an isocyanate-terminated polymer. Alternately, a diacid chloride such as adipoyl chloride, phosgene, or other similar compounds can be reacted with the hydroxy-terminated polymer to give polymers terminated with acid chloride or chloroformate groups. In similar ways, the carboxyl end groups of the carboxy-terminated polymer can be chemically modified to yield any of a variety of functional groups as terminal groups for these polymers. This flexibility in designing the end group or terminal group on the polymer molecule is important because it allows a great range of possibilities in terms of the curing of these materials with other components to fabricate the desired final product, namely the propellant or explosive product.
The reaction time useful for the process of the present invention is not narrowly critical and can vary over a wide range. It is preferred that the reaction time be between about 2 and about 8 hours, more preferably between about 3 and about 5 hours.
Likewise, the reaction temperature is not narrowly critical and can vary over a wide range. Preferably the reaction temperature is between about 60° C. and about 150° C., more preferably between about 95° C. and about 125°, and most preferably between about 105° C. and about 115° C.
The process of the present invention is conducted in the presence of an acid catalyst. Suitable acid catalysts include the following: p-toluene sulfonic acid, sulfuric acid, zinc acetate, cadmium acetate, and any other acid catalyst suitable for esterification reactions. The yield, molecular weight, polymer properties, and process variables will differ depending upon the catalyst employed.
The reaction in accordance with the present invention is preferably suitably conducted, for the most part, at subatmospheric pressure, most preferably at a pressure of between about 0.001 mm of Hg and about 600 mm of Hg. The subatmospheric pressure makes it possible for easy removal of the water by-product from the reaction mixture, thereby driving the polycondensation reaction to completion as desired. Because of the volatility of some of the monomers employed, however, subatmospheric pressure is preferably not applied during the initial stage of the reaction. Alternative or additional methods can be used to remove by-product water from the reaction mixture such as azeotropic distillation, chemical drying, or the like.
The optional polymer purification step, if utilized, is preferably conducted by precipitation in a mixture of a paired solvent/non-solvent. Suitable solvent/non-solvent pairs can be chosen from the following solvents: methylene chloride, chloroform, tetrahydrofuran, or any other organic solvent capable of dissolving the polymers; and the following non-solvents: methanol, ethanol, water, hexane, cyclohexane, benzene or any other organic medium which is not a solvent for polymers. Alternately, other purification methods can be employed such as gel permeation chromatography.
The polymers produced in accordance with the process of the present invention generally have a weight average molecular weight of between about 500 and about 10,000, preferably between about 1000 and about 5000. The glass transition temperature of the polymer (T g ) is generally less than 0° C., preferably less than -10° C., and more preferably less than -15° C. The viscosity of the polymer is generally less than 50,000 centipoise, preferably less than 20,000 centipoise, and more preferably less than 10,000 centipoise.
As used herein, the term "percent" designates weight percent and the term "fraction" designates mole fraction unless otherwise specified.
The aforementioned technical publications are incorporated herein by reference in their entirety.
The following examples are intended to illustrate, but in no way limit the scope of, the present invention.
EXAMPLE 1
Novel Process for Synthesizinq Poly(Diethylene Glycol-4,7-Dinitraza-1,10-Decanedioate) (Also Called "P-DEND") See Polymer 1 of Table 1 Below
A 5 ml one-neck flask equipped with a magnetic stirring bar and a nitrogen adaptor was charged with 1.00 g (4.18 mmol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 0.44 g (4.19 mmol) of diethylene glycol and 3 mg of p-toluene sulfonic acid. The mixture was heated to 100° C. and stirring started when the mixture melted. The mixture was heated for 5 hours and then vacuum was applied for a period of 1.5 hours at 100° C. Then the mixture was cooled to room temperature and dissolved in 3 ml of methylene chloride. The polymer was precipitated by pouring the methylene chloride solution into 40 ml of methanol. The methanol was decanted and the tacky polymer dried in a vacuum oven at 60° C. overnight. The yield of the Polymer 1 product was 0.88 g (69%) based on diacid used. The physical data is given in Table 1. Polymer 1 is a comparison composition (P-DEND) for purposes of the present invention; however, its preparation as described above is believed to be novel.
EXAMPLE 2
Synthesis of Polymer 2 Identified in Table 1
Polymer 2 was prepared by the same method as described for 1 by using 1.54 g (5 mmol) of 5-methyl-4,7-dinitraza-1,10-decanedioic acid (MDNDA), 0.53 g (5 mmol) of diethylene glycol and 3 mg of p-toluene sulfonic acid. The yield 1.45 g (77%) based on diacid used. The physical data is given in Table 1.
EXAMPLE 3
Synthesis of Polymer 3 Identified in Table 1
Polymer 3 was prepared by the same method as described for 1 by using 0.27 g (0.88 mmol) of 5-methyl-4,7-dinitraza-1,10-decanedioic acid (MDNDA), 0.600 g (2.04 mmol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 0.41 g (3.95 mmol) of diethylene glycol and 2 mg of p-toluene sulfonic acid. The yield 0.8 g (69%) based on diacids used. The physical data is given in Table 1.
EXAMPLE 4
Synthesis of Polymer 4 Identified in Table 1
Polymer 4 was prepared by the same method as described for 1 by using 1.08 g (3.5 mmol) of 5-methyl-4,7-dinitraza-1,10-decanedioic acid (MDNDA), 0.44 g (1.5 mol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 0.5311 g (5 mmol) of diethylene glycol and 2 mg of p-toluene sulfonic acid. The yield is 1.46 g (78%) based on diacids used. The physical data is given in Table 1.
EXAMPLE 5
Synthesis of Polymer 5 Identified in Table 1
Polymer 5 was prepared by the same method as described for 1 by using 1.80 g (8.73 mmol) of 4-nitraza-1,7-heptanedioic acid (NHDA), 1.04 g (9.81 mmol) of diethylene glycol and 5 mg of p-toluene sulfonic acid. The yield was 2.44 g (96%) based on diacid used by precipitating the polymer in hexane. The physical data is given in Table 1.
EXAMPLE 6
Synthesis of Polymer 6 Identified in Table 1
Polymer 6 was prepared by the same method as 1 by using 1.47 g (5 mmol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 0.44 g (2.13 mmol) of 4-nitraza-1,7-heptanedioic acid (NHDA), 0.85 g (8.02 mmol) of diethylene glycol and 5 mg of p-toluene sulfonic acid. The yield was 2.08 g (96%) based on diacid used. The physical data is given in Table 1.
EXAMPLE 7
Synthesis of Polymer 7 Identified in Table 1
Polymer 7 was prepared by the same method as 1 by using 0.76 g (2.57 mmol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 1.24 g (6 mmol) of 4-nitraza-1,7-heptanedioic acid (NHDA), 1.02 g (9.63 mmol) of diethylene glycol and 5 mg of p-toluene sulfonic acid. The yield was 2.18 g (95%) based on diacid used. The physical data is given in Table 1.
EXAMPLE 8
Synthesis of Polymer 8 Identified in Table 1
Polymer 8 was prepared by the same method as 1 by using 1.85 g (6 mmol) of 4,8-dinitraza-1,11-undecanedioic acid (DNUDA) 0.72 g (6.74 mmol) of diethylene glycol and 5 mg of p-toluenesulfonic acid. The yield was 1.92 g (93%) based on diacid used. The physical data is given in Table 1.
EXAMPLE 9
Synthesis of Polymer 9 Identified in Table 1
Polymer 9 was prepared by the same method as 1 by using 1.23 g (4 mmol) of 4,8-dinitrazaundecanedioic acid (DNUDA), 0.35 g (1.71 mmol) of 4-nitraza-1,7-heptanedioic acid (NHDA), 0.68 g (6.41 mmol) of diethylene glycol and 4 mg of p-toluene sulfonic acid. The yield was 1.47 g (82%) based on diacids used. The physical data is given in Table 1.
EXAMPLE 10
Synthesis of Polymer 10 Identified in Table 1
Polymer 10 was prepared by the same method as 1 by using 0.62 g (2 mmol) of 4,8-dinitraza-1,11-undecanedioic acid (DNUDA), 0.96 g (4.67 mmol) of 4-nitraza-1,7-heptanedioic acid (NHDA), 0.80 g (7.49 mmol) of diethylene glycol and 5 mg of p-toluene sulfonic acid. The yield was 1.3 g (63%) based on diacids used. The physical data is given in Table 1.
EXAMPLE 11
Synthesis of Polymer 11 Identified in Table 1
Polymer 11 was prepared by the same method as 1 by using 1.08 g (3.5 mmol) of 4,8-dinitraza-1,11-undecanedioic acid (DNUDA), 0.44 g (1.5 mmol) of 4,7-dinitraza-1,10-decanedioic acid (DNDA), 0.60 g (5.62 mmol) of diethylene glycol and 5 mg of p-toluene sulfonic acid. The yield was 1.60 g (95%) based on diacids used. The physical data is given in Table 1.
EXAMPLE 12
Synthesis of Polymer 12 Identified in Table 1
Polymer 12 was prepared by the same method as 1 by using 1.54 g (5 mmol) of 4,8-dinitraza-1,11-undecanedioic acid (DNUDA), 0.36 g (5.88 mmol) of ethylene glycol, and 5 mg of p-toluenesulfonic acid. The yield 1.42 g (85%) based on diacids used. The physical data is given in Table 1.
TABLE I__________________________________________________________________________POLYMER PREPARATION DATA__________________________________________________________________________ PHYSICALMOLAR PERCENTS OF MONOMERS USED PROPERTIES OF THE POLYMERPolymer*DNDA .sup.a○ % MDNDA .sup.b○ % NHDA .sup.c○ % DNUDA .sup.d○ % MW .sup.e○ T.sub.g .sup.f○ (°C. ) Decomposition__________________________________________________________________________ (°C.)1 100 -- -- -- 4253 0 222.02 -- 100 -- -- 1907 0.75 243.23 70 30 -- -- 3664 -6.5 --4 30 70 -- -- 1912 -- --5 -- -- 100 -- 2511 -19.1 228.06 70 -- 30 -- 4775 -9.5 261.47 30 -- 70 -- 2525 -20.5 255.08 -- -- -- 100 2932 -22 256.09 -- -- 30 70 2217 -22 258.210 70 30 2026 -15 261.011 30 70 2880 -20 255.612 -- -- -- 100 2418 -- --__________________________________________________________________________ .sup.a○ 4,7-dinitraza-1,10-decanedioic acid (DNDA). .sup.b○ 5-methyl-4,7-dinitraza-1,10-decanedioic acid (MDNDA). .sup.c○ 4-nitraza-1,7-heptanedioic acid (NHDA). .sup.d○ 4,8-dinitraza-1,11-undecanedioic acid (DNUDA). .sup.e○ Weight average molecular weight. .sup.f○ Glass transition temperature of the polymer.*In Table 1, the various numbered polymers are more specificallyidentified by the empirical structure formulaas follows:[(OOCCH.sub.2 CH.sub.2RCH.sub.2 CH.sub.2 CO).sub.x (OOCCH.sub.2 CH.sub.2R'H.sub.2 CH.sub.2 CO).sub.y (OR")].sub.nwherein -n had a value of between 3 and 10, and wherein: R R' x y R"__________________________________________________________________________ N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) -- 1 0 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 ##STR1## -- 1 0 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) ##STR2## 0.7 0.3 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) ##STR3## 0.3 0.7 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2) -- 1 0 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) N(NO.sub.2) 0.7 0.3 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) N(NO.sub.2) 0.3 0.7 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 CH.sub.2 N(NO.sub.2) -- 1 0 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub. 2)CH.sub.2 CH.sub.2 CH.sub.2 N(NO.sub.2) N(NO.sub.2) 0.3 0.7 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.210. N(NO.sub.2)CH.sub.2 CH.sub.2 CH.sub.2 N(NO.sub.2) N(NO.sub.2) 0.7 0.3 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)CH.sub.2 CH.sub.2 N(NO.sub.2) N(NO.sub.2)CH.sub.2 CH.sub.2 CH.sub.2 N(NO.sub.2) 0.3 0.7 CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 N(NO.sub.2)OH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 N(NO.sub.2) 1 0 CH.sub.2 CH.sub.2__________________________________________________________________________ | Energetic binders, and, more specifically, a class of nitramine-containing homopolymers and co-polymers characterized by favorable viscosity and glass transition temperature are prepared. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a variable phase drive coupling, also herein termed a phaser, for providing drive from an engine crankshaft to two sets of cams, the drive coupling comprising a drive member connectable for rotation with the engine crankshaft and two driven members each connectable with a respective one of the two sets of cams.
SUMMARY OF THE INVENTION
[0002] According to the present invention, there is provided a phaser as set forth above wherein the angular relationship of each of the driven members is independently variable relative to the drive member under the action of camshaft torque reversals.
[0003] Preferably, the driven members are hydraulically coupled for rotation with the drive member and the phase of the driven members is controlled by selectively permitting the flow of hydraulic fluid between the hydraulic chambers.
[0004] Conventionally, hydraulically operated phasers use an engine generated hydraulic oil pressure in order to alter the timing of the camshafts, but the phaser of the preferred embodiments of the present invention relies instead on the pressure generated by the reaction torque reversals of the cams.
[0005] The invention is particularly applicable to engines using an assembled camshaft having two groups of cam lobes mounted on the same shaft, the timing of the two groups of cam lobes being variable in relation to one another. The invention is however alternatively applicable to an engine having one camshaft driven directly from the engine crankshaft and using a secondary drive to operate the second camshaft from the first.
[0006] Preferably, the phaser is a ‘vane-type’ phaser having a number of oil-filled arcuate cavities, each cavity being divided into two parts by a moveable radial vane. Allowing oil to flow from one side of the vane to the other through one-way valves changes the position of the vane in the cavity, thus actuating the phaser.
[0007] Advantageously, the flow of the hydraulic fluid is controlled via two spool valves mounted concentrically.
[0008] It is possible for each of the driven members to be controlled via two oil passages, each of which is fitted with a one-way valve that may be selectively bypassed.
[0009] Alternatively, each of the driven members may be controlled via two oil passages connected to a single one-way valve that controls the direction of flow between the two passages.
[0010] In order to achieve a compact implementation, it is desirable to integrate one or more of the one-way valves into a spool valve.
[0011] As a further possibility, the two driven members may be controlled via three oil passages, the flow through each of which is controlled via the two spool valves.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:
[0013] FIG. 1 is an exploded perspective view of a first embodiment of the invention,
[0014] FIG. 2 is a front view of the phaser of FIG. 1 ,
[0015] FIG. 3 is a longitudinal section through an assembled camshaft fitted with the phaser of FIG. 1 taken in the plane A-A in FIG. 2 ,
[0016] FIG. 4 is a detail of FIG. 3 drawn to an enlarged scale,
[0017] FIG. 5 is an exploded perspective view of the solenoid operated control valve of the phaser in FIG. 1 ,
[0018] FIG. 6 is a plan view of cylinder head using two separate camshafts and a having a phaser of the invention to enable the phase of each of the camshafts to be varied independently relative to the crankshaft, and
[0019] FIGS. 7 to 11 are schematic diagrams showing the design of different hydraulic circuits that may be used for controlling the phaser.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following description will assume a basic understanding of the construction and operation of vane-type phasers which are well documented in the prior art, for example in U.S. Pat. No. 6,725,817.
[0021] A phaser 10 shown in FIGS. 1 to 5 has two pairs of cavities 11 and 13 in its drive sprocket 12 , one diametrically opposed pair of cavities for each of two phased outputs. Vanes 14 and 16 are fixed to front and rear plates 18 and 20 , respectively, of the phaser 10 and are fitted with rubber seals 22 to reduce leakage. The rear plate 20 is integral with the front bearing 32 of an assembled camshaft 30 .
[0022] The camshaft 30 , as shown in FIG. 3 , has an inner shaft 50 rotatable relative to an outer tube 52 . The outer tube is fast in rotation with one set of cams 54 . A second set of cams 56 that are free to rotate about the cuter tube is coupled for rotation with the inner shaft 50 by means of pins 58 that pass through tangentially elongated slots in the outer tube 52 . Such an assembled camshaft is itself well known and is referred to as an SCP (single cam phaser) camshaft.
[0023] The bearing 32 is connected to the inner shaft 50 of the SCP camshaft and drives the cam lobes 56 that can rotate relative to the outer tube of the camshaft. The front plate 18 on the other hand is clamped to the front of the camshaft outer tube 52 via a nut 34 (see FIG. 4 ) and drives all of the cam lobes 54 fixed to the outer tube 52 .
[0024] Two locking pins 40 and 42 are provided to prevent the front and rear plates 18 , 20 from moving under low oil pressure conditions when the engine is starting or stopping. The locking pins 40 and 42 are disengaged by an oil pressure feed from the camshaft front bearing, as shown in FIG. 4 . The oil pressure supply from the front bearing 32 is also used to top-up the oil inside the phaser, to compensate for any leakage, and is connected to the oil circuit inside the phaser by a conventional one-way valve system 60 .
[0025] Each of the phaser outputs is controlled via two one-way valves 70 and 72 , the valves allowing oil to flow into the pair of cavities on opposite sides of their respective vanes, thus allowing the phase of the front/rear plate to be controlled. The flow through the one-way valves 70 and 72 is controlled by a spool valve 80 , shown in exploded view in FIG. 5 .
[0026] The spool valve 80 comprises an inner spool 82 biased by a spring 84 and an outer spool 86 biased by a spring 88 . The two spools 82 and 86 are separated by a stationary separator sleeve 90 and a spool retainer 92 engages both the front end of the outer spool 86 and the front plate 18 of the phaser to ensure that the spool valve 80 does not rotate within the outer tube of the camshaft. A solenoid 93 having two separate coils 91 , 95 operates two concentric actuators each displacing a respective one of the two spools 82 , 86 against the action of its associated spring.
[0027] The operation of the spool valve 80 and the one-way valves 70 and 72 will be better understood by referring to the system diagrams in FIGS. 7 and 8 .
[0028] FIG. 7 , which is in three parts shows the operation of the outer spool 86 of the spool valve that is connected to one set of vanes. The three views in each of FIGS. 7 to 10 show different positions of the valve spools and the way in which they affect the flow in the hydraulic circuit and the effect on the phase of the outputs of the phaser.
[0029] Oil feeds 100 and 102 are provided in FIG. 7 to both sides of the vane 16 , which are each connected via a one-way valve 70 , 72 to a connecting oil gallery 104 . The one-way valves 70 and 72 are arranged such that oil may flow from the oil gallery 104 to either section of the cavity, but oil cannot flow from the cavity into the oil gallery 104 . In its central position, the outer spool 86 blocks the end of both oil feeds 102 and 104 from the cavity 13 and so the vane 16 is unable to move.
[0030] Moving the outer spool 86 to the left (see the second view of FIG. 7 ) will connect the left hand oil feed 100 to the central oil gallery 104 , opening a path for oil to flow out of the working chamber on left side of the vane 16 and back into the chamber on the right side of the vane 16 via the one-way valve 72 in the right hand oil feed 102 . The phaser can therefore only provide torque in an anti-clockwise direction and any torque from the camshaft in the opposite direction will cause the vane to move in an anti-clockwise direction by pushing oil from one side of the cavity to the other.
[0031] Moving the outer spool 86 in the opposite direction as illustrated in the right hand view of FIG. 7 allows the vane 16 to move in a clockwise direction as shown.
[0032] The operation of the inner spool 82 is similar in principle to that of the outer spool 86 , but it controls the other output of the phaser via a second set of vanes 14 . The three views of FIG. 8 illustrate the movement of the inner spool 82 and the associated movement of the vane 14 that will be permitted.
[0033] In order to reach the inner spool 82 , the oil connections need to pass through slots in the outer spool 86 and the stationary spool separator 90 . The slots in the outer spool 86 are designed to ensure that oil flow to the inner spool 82 is not affected by the position of the outer spool.
[0034] Both oil circuits are fed with oil from the engine oil pump in order to replace any leakage, and the feed is connected to the central oil galleries via one-way valves. Two separate valves are required in order to prevent any communication between the two control systems.
[0035] The orientation of the outer spool 86 needs to be controlled in order to ensure that its slots and its drillings for transferring oil to the inner spool are correctly aligned to the holes in the front of the camshaft tube 52 . This is achieved by the spool retainer 92 which both retains the outer spool 86 inside the phaser and prevents it from rotating.
[0036] It would be possible to apply the same type of phasing system to an engine having conventional twin camshafts, using a secondary gear or chain connection to drive the second camshaft from the first. Such an embodiment is illustrated in FIG. 6 in which two solid camshafts 200 and 202 are mounted parallel to one another in the engine cylinder head. The camshaft 200 is connected to the front plate of the phaser 204 and instead of driving the inner shaft of an assembled camshaft, the rear plate of the phaser 204 drives a sprocket 206 connected to drive the second camshaft 202 .
[0037] It will be appreciated that the invention is not restricted to the hydraulic circuit described above and that various alternative designs may be adopted, examples of such alternative hydraulic circuits being shown in FIGS. 9 to 11 . Most of the components of these circuits operate in analogous manner to that already described and the ensuing description will therefore be restricted to the points of difference.
[0038] The embodiment of FIG. 9 uses a single one-way valve 250 to replace the valves 70 and 72 in FIG. 7 . The single one-way valve 250 is positioned at the intersection of the central oil gallery 104 with the two oil feeds from the vane cavity. The valve 250 needs to be designed to isolate the two oil feeds from each other when it is closed, hence it has a long parallel section.
[0039] The top up oil feed from the engine oil pump is fed into the system through the middle of the one-way valve 250 via a simple ball valve. This arrangement causes the one way valve to be forced onto its seat by the engine oil pressure and the valve will only open when the pressure in the central gallery exceeds the engine oil pressure.
[0040] The operation of the system is identical in all other respects as illustrated in FIG. 7 . Moving the spool to the left connects the left hand oil feed to the central gallery 104 , allowing the vane 16 to push oil out of the left hand side of the cavity and move in an anti-clockwise direction. Moving the spool 86 to the right connects the right hand oil feed to the central gallery, allowing the vane 16 to push oil out of the right hand side of the cavity and move in a clockwise direction.
[0041] The embodiments of FIGS. 10 and 11 have one-way valves 170 , 172 positioned within the inner valve spool instead of being mounted in the main body of the phaser.
[0042] These figures also show how the two phaser outputs may be controlled using three oil feeds 300 , 302 , 304 rather than four (two each of oil feeds 100 and 102 ) to control both the outputs of the phaser. The embodiments of FIGS. 10 and 11 operate in essentially the same manner and differ only in that in FIG. 10 the vanes 14 and 16 driving the two outputs share a common cavity whereas in FIG. 11 two separate cavities are used as in the previously described embodiments but two of the chambers of the cavities are directly connected to one another.
[0043] In these embodiments, the outer spool is used to determine which of the three feeds is connected to the inner spool. The inner spool is used to control the direction of oil flow between the two oil feed paths that are connected to it. Moving the inner spool to the left allows oil from the left hand feed to flow into the bore of the spool, pass through to the right hand of the bore via a one way valve 170 , 172 and out into the right hand feed. Moving the inner spool to the right allows oil from the right hand feed to flow into the bore of the spool, pass through to the left hand end of the bore via the one way valve and out into the left hand oil feed.
[0044] Two separate top-up oil feeds 306 , 308 from the engine oil supply are shown in FIG. 11 at the bottom of each view.
[0045] The left hand view of FIG. 10 shows the outer spool in its central position where the two outer oil feeds are connected to the inner spool and the centre oil feed is blocked. This will allow oil to be transferred between the two outer sections of the cavity whilst the middle section remains the same.
[0046] The middle view of FIG. 10 shows the outer spool moved to the left, such that the right hand oil way is blocked and the inner spool is connected to the left hand and central oil ways. This will allow oil to be transferred between the left hand and the central sections of the cavity whilst the right hand section remains the same.
[0047] The right hand view of FIG. 10 shows the outer spool moved to the right, such that the left hand oil way is blocked and the inner spool is connected to the central and right hand oil ways. This will allow oil to be transferred between the central and the right hand sections of the cavity whilst the left hand section remains the same.
[0048] Intermediate positions of the outer spool will allow all three sections of the cavity to be controlled at the same time. However, there is no position of the outer spool that will allow oil to flow out of the central section and into both outer sections, or allow oil to flow out of both outer sections and into the central section.
[0049] The oil feeds can be designed to permit this type of variation if required, but there will be a different flow regime that becomes precluded instead.
[0050] The different embodiments of the invention offer the following advantages when compared to existing vane-type phaser designs:
The phaser requires only a ‘top up’ oil feed, hence reducing oil consumption. The response speed of the phaser is not dependent upon oil supply pressure. No complex oil control drillings are required in the cylinder head or block. No oil drainage problems result from large quantities of ‘waste’ oil. | A variable phase drive coupling is described for providing drive from an engine crankshaft to two sets of cams. The drive coupling comprising a drive member 12 connectable for rotation with the engine crankshaft and two driven members 18, 20 each connectable with a respective one of the two sets of cams. In the invention, the angular relationship of each of the driven members 18, 20 is independently variable relative to the drive member 12 under the action of camshaft torque reversals. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and apparatus for electrically heat welding thermoplastic fittings, and more particularly, to improved methods and apparatus for automatically electrically heat welding thermoplastic fittings to other thermoplastic members such as pipe sections.
2. Description of the Prior Art
Electric heat weldable fittings formed of thermoplastic material have been developed and used heretofore. Such fittings generally include an electric resistance heating coil or element positioned adjacent the inside surfaces of the fitting which are to be welded to one or more other thermoplastic members such as pipe joints. The electric resistance heating element is usually a coil of resistance wire disposed in the thermoplastic material of the fitting. Electric contacts are attached to an outside surface of the fitting so that a source of electric power can be applied to the heating coil. Examples of electric heat weldable thermoplastic fittings are described in U.S. Pat. No. 4,147,926 issued Apr. 3, 1979 and U.S. Pat. No. 4,349,219 issued Sept. 14, 1982.
When electric power is applied to the resistance heating element of a fitting, the heating element heats the fitting and adjacent portions of thermoplastic members to temperatures which cause the thermoplastic materials from which the fitting and adjacent members are formed to melt whereby they become fused or welded together. The quality of the weld which results is primarily dependent upon the correct quantity of electric power being supplied to the heating element of the fitting. If too little electric power is supplied, an inadequate low strength weld results. If too much electric power is supplied, the fitting and adjacent members to which the fitting is welded can be overheated and deformed whereby a good weld does not result.
Various types of control and electric power generating apparatus have been utilized for supplying the electric power to electric heat weldable thermoplastic fittings. Initially, such apparatus were manually controlled by an operator and the quantities of electric power supplied to the heating elements of the fittings were determined by visual observation. More recently, control apparatus have been developed whereby the particular heating element and fitting to be welded are identified and electric power is supplied to the heating element in a preset quantity. For example, U.S. Pat. No. 4,602,148 issued July 22, 1986 and U.S. Pat. No. 4,631,107 issued Dec. 23, 1986, describe methods and apparatus which automatically identify the particular heating element and fitting to be welded, a controlled quantity of electric power is supplied to the heating element of the fitting and the welding process is monitored so that if an abnormality therein is detected, the welding process is terminated.
Improvements have been made to the methods and apparatus for electrically heat welding thermoplastic fittings of the type described above. For example, U.S. Pat. No. 4,642,155 issued Feb. 10, 1987 and U.S. Pat. No. 4,684,789 issued Aug. 4, 1987, disclose methods and apparatus which initially measure the resistance and/or impedance of the heating element using electric power at a minimum voltage level which does not significantly heat the element to more accurately determine the size of the fitting to be welded. In addition, the electric power supplied to the heating element of the fitting during the welding process is alternating current electric power which by adjusting the frequency thereof can be made to cause the vibration of the fitting which improves the quality of the weld obtained.
A problem which has not yet been solved in the electric heat welding of thermoplastic fittings involves the situation where the heating element of the fitting is partially shorted out as a result of improper installation or other reason. When electric power of substantially constant voltage is supplied to such heating elements and when a short circuit develops, the resistance of the heating element decreases which causes the current level to increase, often to a level whereby the ignition point of the thermoplastic material is reached and a fire or other dangerous condition occurs. While an automatic electric power apparatus of the type described above which determines abnormalities in the welding process terminates the welding process when a high current level is experienced, the end result is that the fitting and adjacent portions of pipe joints or the like must be replaced and the welding thereof repeated.
By the present invention improved methods and apparatus for electrically heat welding thermoplastic fittings to adjacent thermoplastic members are provided whereby when a short circuit in the heating element occurs, the current level is prevented from rising appreciably and controlled at a predetermined current level to prevent overheating and, in most cases, to complete the welding process whereby an acceptable weld is made.
SUMMARY OF THE INVENTION
Methods and apparatus for electrically heat welding thermoplastic fittings having electric resistance heating elements disposed therein are provided. The methods each basically comprise the steps of connecting the heating element of a fitting to an electric power source; sensing the initial temperature of the heating element of the fitting; supplying electric power to the heating element at a controlled substantially constant voltage whereby said heating element is heated; sensing the initial magnitude of the current flowing through the heating element and comparing such magnitude and the initial temperature of the element with predetermined current levels for heating elements of various sizes of fittings at various temperatures to thereby determine size of the fitting being welded, the total time the controlled substantially constant voltage should be supplied to the heating element and the current levels for such size of fitting which should result over the time period to ensure the making of a high quality weld; continuing to sense the magnitude of the current flowing through the heating element over the time period the electric power is supplied thereto and comparing such magnitude at predetermined time intervals with the predetermined current levels for the size and fitting being welded to thereby determine if the welding process is proceeding abnormally at such time intervals; terminating the supply of electric power to the heating element at the end of the total time period required to make a high quality weld or when it is determined that the welding process is proceeding abnormally unless the abnormality is that the current level is too high; and when the abnormality is that the current level is too high, reducing the voltage level to that which results in current levels substantially equal to the predetermined current levels for the remaining of the predetermined time and then terminating the supply of electric power to the heating element of the fitting.
In a preferred method, electric power is initially supplied to the heating element of the fitting at a minimum voltage level for measuring the impedance and optionally, the resistance of the heating element without significantly heating the element; the impedance and optionally, the resistance of the heating element are measured; and the size of the heating element and of the fitting are determined by comparing the measured impedance and optionally, the quality factor of the fitting with predetermined impedances and optionally, quality factors for various sizes of heating elements and fittings.
In a most preferred embodiment, the method also includes the steps of determining the deviation between the initial substantially constant voltage supplied to the heating element of the fitting being welded and the reduced voltage supplied thereto after an abnormality whereby the current level is too high has occurred, and providing an indication of a poor quality weld when the voltage deviation is greater than a predetermined voltage deviation for that size of fitting.
It is, therefore, the general object of the present invention to provide improved methods and apparatus for electrically heat welding thermoplastic fittings.
A further object of the present invention is the provision of methods of electrically heat welding thermoplastic fittings wherein abnormalities occurring during the welding process are detected and when a good quality weld cannot be obtained as a result, the welding process is terminated.
Yet another object of the present invention is the provision of methods of electrically heat welding thermoplastic fittings wherein when the welding process is determined to be abnormal but a good weld can still be obtained, the welding process is completed rather than being terminated.
Other and further objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon a reading of the description of preferred embodiments which follows when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an electric heat weldable thermoplastic sleeve having the ends of a pair of pipe sections inserted therein with electric power and control apparatus illustrated schematically in relation thereto.
FIG. 2 is an enlarged cross-sectional view of portions of the fitting, plastic pipe sections and electric power and control apparatus of FIG. 1.
FIG. 3 is a graph showing the current-time relationships of different fittings.
FIG. 4 is a graph showing the current-time relationship of a particular fitting welded in accordance with the present invention wherein an abnormality resulting in the current being too high was detected.
FIG. 5 is a graph showing the voltage-time relationship for the fitting welded in accordance with the present invention which resulted in the current-time relationship shown in FIG. 4.
FIG. 6 is a schematic illustration of electric power and control apparatus for carrying out the method of the present invention connected to a thermoplastic fitting having a resistance heating element disposed therein.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, and particularly to FIGS. 1 and 2, an electric heat weldable thermoplastic sleeve 10 is illustrated with the ends of a pair of thermoplastic pipe sections 12 and 14 inserted therein. The sleeve 10 includes a pair of electric contact connectors 16 and 18 attached thereto for receiving complimentary electric connections 20 and 22 attached to the ends of electric cables 24 and 26, respectively. The cables 24 and 26 are connected to an electric power and control apparatus, generally designated by the numeral 30. As best shown in FIG. 2, the thermoplastic fitting 10 includes an electric resistance heating element 28 disposed therein adjacent portions of the interior surface 32 thereof. The resistance heating element 28 can take various forms, but preferably is a coil formed of electric resistance heating wire disposed in a spiral winding within the thermoplastic material forming the sleeve 10 adjacent the portions of the interior surface 32 which are to be welded to the exterior surfaces of the pipe sections 12 and 14. The opposite ends of the heating wire 28 are connected to upstanding electric contact pins 34 and 36 disposed within the connectors 16 and 18. The complimentary connectors 20 and 22 of the electric power and control apparatus 30 are adapted for removable connection to the connectors 16 and 18 of the sleeve 10.
The connectors 20 and 22 include electric contact sockets 38 and 40, respectively, for engagement with the electric contact pins 34 and 36 of the connectors 16 and 18. The socket contact 38 is connected to a wire 39 extending through the cable 24 and the socket contact 40 is connected to a wire 41 extending through the cable 26. The connector 22 also includes a temperature sensing device 42 such as a thermister, RTD, or thermocouple positioned in heat conducting relationship with the socket contact 40. The temperature sensing device 42 is connected to a multiple lead wire 43 also extending through the cable 26. The device 42 senses the temperature of the contact pin 36 when the socket contact 40 is engaged with the pin 36. That is, when the connector 22 is connected to the connector 18 of the sleeve 10, the temperature sensing device 42 senses an initial temperature which is representative of the temperature of the entire sleeve 10 including the heating element 28.
As will be described further hereinbelow, when the fitting 10 is to be fused or welded to the pipe sections 12 and 14, the connectors 20 and 22 attached to the cables 24 and 26 are removably connected to the connectors 16 and 18 of the sleeve 10 whereby an electric circuit is completed between the heating element 28 of the fitting 10 and the electric power and control apparatus 30. The electric power and control apparatus 30 provides electric power to the heating element 28 which causes the heating element to heat the thermoplastic materials forming the sleeve 10 and the ends of the pipe sections 12 and 14 inserted within the interior of the sleeve 10. The heating causes the thermoplastic materials of the fitting 10 and pipe sections 12 and 14 to melt and fuse together to thereby form welds between the fitting 10 and the pipe sections 12 and 14.
Referring now to FIG. 6, the electric power and control apparatus 30 of the present invention is illustrated connected to the heating element 28 of the sleeve 10 by way of the cables 24 and 26 and the connectors 16, 18, 20 and 22. The apparatus 30 includes a variable voltage electric power source 45 which is connected by the wires 39 and 41 extending through the cables 24 and 26 to the contact sockets 38 and 40 of the connectors 20 and 22. A low voltage electric power source 47 is also included in the apparatus 30 which is connected to the wires 39 and 41 by wires 53 and 55, respectively. The contact sockets 38 and 40 of the connectors 20 and 22 are connected to the contact pins 34 and 36 of the connectors 16 and 18 of the sleeve 10 which are in turn connected to the heating element 28 of the fitting 10.
A current sensor 46 for sensing the current flowing from the power source 45 to the heating element 28 is electrically connected to the power source 45 by a lead 59 with the output signal therefrom connected by a lead 48 to an electronic computer 50. The computer 50 is connected to the variable voltage electric power source 45 by a lead 49 by means of which the computer 50 controls the voltage level of the electric power supplied by the electric power source 45. A voltage sensor 71 for sensing the voltage of the electric power supplied by the electric power source 45 is connected thereto by a lead 73 with the output signal therefrom connected by a lead 75 to the computer 50. An impedance-resistance sensor 57 for sensing the impedance and resistance of the heating element 28 when minimum voltage electric power is applied thereto is electrically connected to the power source 47 by a lead 61 with the output signal therefrom connected to the computer 50 by a lead 63. The previously described temperature sensing device 42 is connected by the wire 43 attached thereto and extending through the cable 26 to the computer 50.
A switch device 52 such as a TRIAC or SCR is provided in the circuit between the heating element 28 and the power source 45 which is operably connected to the computer 50 by a lead 54. A similar switch device 65 is provided in the circuit connecting the power source 47 to the wires 39 and 41 which is connected to the computer 50 by a lead 67. The computer 50 includes a readout module 51 operably connected thereto for visually indicating various modes of operation of the apparatus 30 such as a shut-down due to a defective fitting, etc. Also, the computer 50 is connected to a communication interface 69 by a lead 70 which in turn can optionally be connected to a modem 72, a second computer 74 and a printer 76.
In operation of the apparatus 30 for electrically heat welding the thermoplastic fitting 10 by means of the heating element 28 disposed therein, the connectors 20 and 22 are first connected to the connectors 16 and 18 of the fitting 10. When the apparatus 30 is turned on, the computer 50 first senses the temperature of the heating element 28 and the fitting 10 by way of the temperature sensing device 42 and lead 43. The computer 50 then closes the switch device 65 thereby completing a circuit between the low voltage electric power source 47 and the heating element 28 of the fitting 10 by way of the wires 39, 41, 53 and 55 connected therebetween. The low voltage electric power applied to the heating element 28 is initially alternating current and then direct current at minimum levels sufficient for the sensor 57 to measure the impedance and then the resistance of the element 28 without significantly heating the element 28. The impedance and resistance values so measured are communicated to the computer 50 by the lead 63 and the computer 50 then opens the switch 65.
The impedance of the heating element 28 is measured when alternating current at a preselected frequency is applied thereto. The impedance so measured can be used by itself to determine the size of fitting to be welded without measuring the direct current resistance. That is, the measured impedance of the heating element 28 can be compared by the computer 50 with predetermined heating element impedances for various sizes of elements and fittings to determine the size of the heating element 28 and fitting 10. Preferably, however, after the impedance of the heating element 28 is measured by the sensor 57, the low voltage electric power supplied to the heating element 28 is changed to direct current and the resistance of the heating element is measured. The measured resistance is used by the computer 50 along with the measured impedance to calculate the quality factor of the heating element 28. The quality factor is determined by dividing the impedance by the resistance, and such factor is compared by the computer 50 to predetermined quality factors for various sizes of heating elements and fittings to determine the size of the heating element 28 and fitting 10 to be welded. While as stated above, the impedance alone can be used to determine the size of the heating element and the fitting to be welded, it is preferred that the computer 50 first determine such size using an impedance and then confirm the size using the calculated quality factor for the heating element as described above. The computer 50 can also confirm the initial temperature sensed by the device 42 using the measured resistance by comparing such resistance with predetermined resistances at various temperatures for the size of heating element and fitting to be welded as determined from the measured impedance and/or quality factor.
The computer 50 next closes the switch device 52 thereby completing a circuit between the variable voltage electric power source 45 and the heating element 28 by way of the wires 39 and 41 connected therebetween. The electric power supplied by the electric power source 45 is controlled by the computer 50 at a preselected substantially constant voltage level, e.g., 40 volts. The initial magnitude of the current flowing through the heating element 20 as a result of the substantially constant voltage electric power supplied thereto is sensed by the computer 50 by means of the current sensor 46 and lead 48. The initial temperature of the heating coil 28 and the initial magnitude of the current flowing therethrough are compared by the computer 50 with predetermined current levels for the size of fitting being welded at various temperatures to again determine and confirm the size of the fitting being welded. In the event the determinations and confirmations of the size of fitting being welded cannot be reconciled by the computer 50, the supply of substantially constant voltage electric power to the element 28 is terminated and the reason for the termination is indicated by the readout 51.
As will be understood, the size of the heating element 28 and the fitting 10 being welded can be determined solely as described above after the substantially constant voltage electric power is supplied to the heating element 28 by the electric power source 45. However, it is preferred that the size of the heating element and fitting first be determined from the quality factor thereof as described above, and that such size be confirmed after the substantially constant voltage electric power is supplied to the heating element. Once the size of the electric heating element 28 and fitting 10 has been determined and confirmed, the supply of the substantially constant voltage electric power to the element 28 is continued, and the total time such power should be supplied to the element 28 to insure the making of a high quality weld is determined by the computer 50.
Referring to FIG. 3, the current-time relationship during the making of a high quality weld for two different sizes of fittings using a standard substantially constant voltage electric power is illustrated graphically. The top curve, designated by the numeral 60, represents the welding process for a two-inch sleeve and the bottom curve, designated by the numeral 62, represents the welding process for a one-inch sleeve. As shown, the current levels are different for the different sizes of sleeve, and each size and type of electrically heat weldable thermoplastic fitting has a current-time relationship which is characteristic of that fitting when a high quality weld is formed using a proper quantity of substantially constant voltage electric power at the same voltage level.
The computer 50 includes resistance-temperature, impedance-temperature, time-temperature and current-time relationship information for a variety of electric heat weldable thermoplastic fittings in memory whereby the computer 50 can make the comparisons described above to initially determine the size of fitting being welded or to confirm such size. The computer 50 also determines the total time the controlled substantially constant voltage electric power should be supplied to a particular heating element for the making of a high quality weld from the information in memory and the initial temperature of the fitting. For example, referring to FIG. 3, if the initial magnitude of the current flowing through the heating element of a fitting is that designated by the numeral 64, the computer will confirm that the fitting is a two-inch sleeve represented by the curve 60. The computer will also then determine from the curve 60 that the total time the controlled substantially constant voltage electric power should be supplied to the heating element for the making of a high quality weld is the time designated by the numeral 66.
The computer 50 continues to sense the magnitude of the current flowing through the heating element of the fitting being welded over the time the controlled electric power is supplied thereto and compares such magnitude at predetermined time intervals with predetermined current levels for the size of fitting being welded. For example, in welding the two-inch sleeve represented by the curve 60 in FIG. 3, the computer compares the actual current levels with the current levels of the curve 60 at frequent predetermined time intervals. As long as the sensed current levels are substantially the same as the current levels in memory for the size of fitting being welded at the standard substantially constant voltage electric power, the computer continues the welding process to the time determined to be required for the making of a high quality weld, i.e., the time 66. If the sensed current levels indicate an abnormality in the welding process, i.e., a deviation from the current levels in memory of a magnitude indicating the welding process is proceeding abnormally, e.g., the deviation shown by the dashed line 68 of FIG. 3, the computer 50 terminates the welding process by turning off the electric power supplied to the fitting being welded. The termination and the reasons therefor are indicated by the computer 50 by way of the readout 51.
Heretofore, the welding process was terminated when any abnormality therein was indicated by the current levels experienced during the process. In the situation where the abnormality was that the current levels were too high as a result of the development of one or more shorts in the heating coil, the electric power had to be terminated in order to avoid exceeding the ignition point of the thermoplastic material. Even if the ignition point of the thermoplastic material was not exceeded, the thermoplastic material would be degraded by excess heat to the point where a poor quality weld would result.
In accordance with the method of the present invention, the electric power supplied to the fitting being welded is not terminated in the situation where the current level is too high. Instead, when an abnormally high current level in the welding process is determined by the computer 50, it reduces the voltage level of the electric power supplied to the fitting, and controls the voltage of the electric power at levels such that the current flowing through the heating element is maintained at the proper levels for a normal fitting. If the deviation in voltage required to control the current is less than a predetermined deviation, the computer 50 continues supplying electric power to the fitting while controlling the voltage thereof to maintain the predetermined current levels to the end of the time determined to be required for the making of a high quality weld. The computer 50 indicates by way of the readout 51 that an abnormally high current was detected which was prevented from remaining high by lowering the voltage of the electric power supplied to the fitting. Such high current will normally be the result of a short circuit in the heating element and because the current level was prevented from going too high, a good weld will normally result. Upon being informed by the readout 51 that a high current abnormality was detected, etc., the operator of the apparatus 30 can visually inspect the fitting 10 and the welds produced to insure that the welds are in fact good.
Referring to FIGS. 4 and 5, the current-time relationship (FIG. 4) and the voltage-time relationship (FIG. 5) during the making of a weld where an abnormality comprised of too high a current level was determined are illustrated graphically for the two-inch sleeve represented by the curve 60 of FIG. 3. As illustrated in FIG. 4, the currenttime curve 80 shows that the welding process proceeding normally for an initial time period to a point 82 where an abnormally high current level due to a short circuit in the heating element was determined. At the point 82, the computer 50 lowered the voltage of the electric power supplied to the fitting and controlled the voltage to maintain the current flowing through the heating coil at a constant level over the remaining time in the welding process. As shown in FIG. 5 by the curve 84, the voltage of the electric power supplied to the fitting was maintained at a substantially constant level for the initial normal portion of the welding process. At a point 86 corresponding to the point 82 of FIG. 4, the computer 50 lowered the voltage of the electric power supplied to the fitting to maintain the constant current levels illustrated in FIG. 4. If the deviation of the lowered voltage level from the normal substantially constant voltage level is greater than a predetermined deviation, as for example the deviation shown by dash line 88, the computer 50 would determine that the abnormality which caused the high current level was more than a partial short circuit of the heating element and terminate the welding process by activating the switch device 52.
In order to facilitate the making of a high quality weld, alternating current is preferably supplied to the heating element 28 of the fitting 10 being welded by the variable voltage electric power source 45 of the apparatus 30. The frequency of the alternating current is adjusted to that frequency which best causes the fitting being welded to vibrate as a result of the magnetic fields produced by the alternating current flowing through the heating element of the fitting. Such vibration facilitates and promotes the fusing of the softened thermoplastic materials of the fitting 10 and other thermoplastic members being welded thereto.
During and upon completion of the welding process described above, the computer 50 records in its memory the various temperatures, current magnitudes, corresponding times and other variables sensed and determined during the welding process. For example, the computer 50 can record the initial temperature of the heating element and fitting, the size of the fitting, the total time the substantially constant voltage electric power should be supplied; the magnitudes of current flowing over the time the substantially constant voltage electric power is supplied to the fitting; and when a high current level abnormality is detected, the time when it occurred, the lower levels of voltage required to maintain the current constant, the final temperature of the heating element, and the total time the electric power is supplied to the heating element. Such recorded information can be communicated to a second computer 74 at a remote location by way of the communication interface 69 and a modem 72 connected thereto. The information can be printed by a printer 76 connected to the computer 74 or utilized in any other desired way. If the supply of electric power is terminated as a result of the welding process proceeding abnormally, the nature of the abnormality will be apparent from the recorded information.
Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned as well as those inherent therein. While presently preferred embodiments of the invention have been described for purposes of this disclosure, numerous changes in the arrangement of steps and parts can be made by those skilled in the art, which changes are encompased within the spirit of this invention as defined by the appended claims. | An improved method and apparatus for electrically heat welding a thermoplastic fitting having an electric resistance heating element disposed therein. A controlled quantity of electric power is supplied to the heating element during the welding process to insure the making of a high quality weld. After the size of heating element and fitting are determined, a substantially constant voltage level electric power is supplied to the heating element of the fitting. When it is determined that the welding process is proceeding abnormally, the supply of electric power is terminated unless the abnormality is that the current level is too high. In that case, instead of terminating the welding process, the voltage of the electric power is reduced to that which results in current levels substantially equal to predetermined current levels for the size of heating element and fitting being welded which often results in a good weld being obtained even where the heating element is partially shorted out. Also, fires and other problems which have heretofore resulted due to such short circuits are prevented. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to the field of oil and gas exploitation, more specifically to systems and methods for well control, especially for well pressure control in wells with hydrocarbon fluids, as defined in the enclosed independent claims.
BACKGROUND ART
[0002] Drilling for oil and gas in deep waters or drilling through depleted reservoirs is a challenge due to the narrow margin between the pore pressure and fracture pressure. The narrow margin implies frequent installation of casing, and restricts the mud circulation due to pressure drop in the annulus between the wellbore and drill string or in other words the increase in applied or observed pressure in the borehole due to the drilling activity such as circulation of drilling fluid down the drill pipe up the annulus of the well bore. Reducing this effect by reducing the circulating flow rate, will again reduces drilling speed and causes problems with transport of drill cuttings in the borehole.
[0003] Normally, in conventional floating drilling with a marine drilling riser installed, two independent pressure barriers between a formation possibly containing hydrocarbons and the surroundings are required. In conventional subsea drilling operations, normally, the main (primary) pressure barrier is the hydrostatic pressure created by the drilling fluid (mud) column in the borehole and drilling riser up to the drilling installation. The second barrier comprises the Blow-Out Preventer (BOP) connected to the subsea wellhead on seabed.
[0004] A conventional drilling system is shown in FIG. 1 a.
[0005] If a formation is being drilled where the hydrostatic pressure of the drilling fluid is not sufficient to balance the formation pore pressure, an influx of formation fluids that may contain natural gas could enter the wellbore. The primary barrier is now no longer effective in controlling or containing the formation pore pressure. In order to contain this situation, the subsea Blow Out Preventer (BOP) must be closed. In a conventional drilling system the oil and gas industry has developed certain standard operational well control procedures to contain the situation for such an event. These are well established and known procedures and will here only be described in broad general terms.
[0006] FIG. 1 a illustrates a conventional subsea drilling system. If the pressure in the borehole 1 due to the hydrostatic pressure from the drilling fluid is lower than the pore pressure in the formation being drilled, an influx into the well bore might occur. Since the density of the influx is lower (in most cases) than the density of the drilling fluid and now occupy a certain height of the wellbore, the hydrostatic pressure at the influx depth will continue to decrease if the well can not be shut in using the BOP. By shutting in the well by closing one of several elements 15 a, b, c, d , 16 in the subsea BOP stack 3 and trapping a pressure in the well 14 , the influx from the formation can be stopped (see FIG. 1 b ). The procedures of containing this situation and how the influx is circulated out of the well by pumping drilling fluid down the drillstring 8 out of the drillbit 10 and up the annulus of the wellbore 14 is well established. The valves in the choke line 25 is opened on the subsea BOP to the high pressure (HP) choke line 24 and the bottom hole pressure controlled by the adjustable choke 22 on top of the coke line on the drilling vessel above the body of water. Downstream the adjustable choke valve, the well stream is directed to a mud-gas separator 42 . This is a critical operation, particularly in deep water areas as there are very narrow margins as to how high the surface pressure upstream the surface choke can be before the formation strength is exceeded in the open hole section.
[0007] Floating drilling operations are often more critical compared to drilling from bottom supported platforms, since the vessel is moving due to wind, waves and sea currents. This means that the floating drilling vessel and the riser may be disconnected from the subsea BOP and wellbore below. If heavier than seawater drilling fluid is being used, this will result in a hydrostatic pressure drop in the well. Generally, a riser margin is required. A riser margin is defined as the needed density (specific gravity) of the drilling fluid in the borehole to over-balance any formation pore pressure after the drilling riser is disconnected from the top of the subsea BOP near seabed in addition to the seawater pressure at the disconnect point 20 . When disconnecting the marine drilling riser from the subsea BOP, the hydrostatic head of drilling fluid in the bore hole and the hydrostatic head of sea water should be equal or higher than the formation pore pressure (FPP) to achieve a riser margin. Riser margin is difficult to achieve, particular in deep waters. The reason is that there can be substantial pressure difference between the pressure inside the drilling riser due to the heavy drilling fluids and the pressure of seawater outside the disconnect point on the riser. To compensate for the pressure reduction in the open hole falling below the pore pressure when the riser is disconnected, would require drilling with a very high mud weight in the well bore and riser. So when drilling with this heavy mud weight all the way up to the spill point on the rig 5 , normally being between 10 to 50 m above sea level, the bottom hole pressure would be higher than the formation strength is able to support. Hence the formation strength would be exceeded and mud losses would occur. It would no longer be possible to circulate and transport the drill cuttings out of the borehole and the drilling operation would have to stop.
[0008] Riser Less Drilling, Dual Gradient Drilling and drilling with a Low Riser Return System (LRRS), have been introduced to reduce some of the above mentioned problems. The LRRS is described in, e.g., WO2003/023181, WO2004/085788 and WO2009123476, which all belong to the present applicant.
[0009] In dual gradient (DG) drilling systems a high density drilling fluid is used below a certain depth in the borehole, with a lighter fluid (for example sea water or other lighter fluid) above this point. When drilling with a riser, a dual gradient effect could be achieved by diluting the drilling riser contents with a gaseous fluid for example, or another lighter liquid, U.S. Pat. No. 6,536,540 (de Boer). Another method could be to install a pump on the seabed or subsea and keep the riser content full or partially full of seawater instead of mud while the returns from the well bore annulus is pumped from seabed up to the drilling installation in a return path external from the main drilling riser. Hence there are two different density liquids in addition to the atmospheric pressure creating the hydrostatic pressure on the underground formation. References are made to prior art, U.S. Pat. No. 4,813,495 (Leach) and U.S. Pat. No. 6,415,877 (Fincher et. al.).
[0010] Another technology that could create a riser margin is the single mud gradient, Low Riser Return System (LRRS) belonging to the applicant. Here, a pump is placed somewhere between the sea level and sea bed and connected to the drilling riser. The drilling mud level is lowered to a depth considerable below the sea level. Due to the shorter hydrostatic head (height) of the drilling fluid acting on the open hole formation, the density of the drilling mud could be increased without exerting excess pressure acting on the formation. If this heavy drilling mud was carried all the way back to the drilling rig, as the case would be in a conventional drilling operation, the hydrostatic pressure would exceed the formation strengths, and hence mud losses would occur.
[0011] In riserless drilling, there is simply not a riser installed hydraulically connecting the seabed installed BOP to the drilling rig trough a marine drilling riser. Normally, the top of the wellbore (subsea BOP) is kept open to seawater pressure during drilling; hence the hydrostatic wellbore pressure is made up of the seawater pressure acting on the well at seabed, plus the hydrostatic pressure of the drilling fluid in the well below this point, also described in U.S. Pat. No. 4,149,603 (Arnold).
[0012] Several other concepts have been introduced and are in the public domain.
[0013] Other systems have introduced a closing element on top of the subsea BOP that can isolate the seawater pressure at seabed from acting on the borehole annulus (U.S. Pat. No. 6,415,877). Such closing element could be a so called Rotating Control Device (RCD) or a rotating BOP. These are somewhat different from an annular preventer in that it is possible to rotate the drill string while sealing pressure from below or above (seawater). It is not recommended practice to rotate the drillstring while a conventional annular BOP is closed during drilling due to excess wear on the rubber element. If such a system is used in combination with a subsea mudlift pump at seabed or mid sea, the suction pressure of the mud pump below the RCD in addition to the drilling fluid height and dynamic pressure loss in the annulus, directly control the pressure in the borehole.
[0014] Common for all these drilling systems is that the drilling fluid returning from the well cannot be returned through high pressure choke or kill lines in a conventional manner due to limited formation strength when the BOP is closed after an influx has occurred. Due to the heavy mud weight required or used, this mud will be displaced out of the wellbore annulus ahead of the lighter influx, hence the formation strength cannot support to be hydraulically in contact with the surface installation when the annulus of the wellbore and the conduit (kill or/and choke lines) back to surface are filled with the heavy drilling fluid. This effect will restrict the use of earlier systems or will put severe strain and requirement on the equipment and processes in a well control event.
[0015] In dual Gradient Drilling and riserless drilling, many types of Subsea Lift Pumps (SLP) can normally not handle a significant amount of gas from the well, as the case may be in a well control event for a gas kick. There are several reasons for this. In normal operations these pumps must handle a significant amount of drill cuttings and rocks in addition to the fine solid particles of the weight materials used in the drilling mud. If a gas influx is introduced into the wellbore at a considerable depth and pressure, this gas will expand when circulated up the bore hole to the seabed or mid-ocean where the pump is located. If this return path of fluids from the well has to go directly into the pump, it will put severe strain on the pump system.
[0016] Secondly, the bottom hole pressure will be a direct function of the fluid head in the annulus, the dynamic pressure loss in the annulus and the pump suction pressure. It will be extremely difficult to achieve a stable and controllable suction pressure on the pump when you will have slugs of high concentration hydrocarbon gas flowing directly into the pump system. As a consequence it will be a great advantage if the hydrocarbon gas and drilling fluid could be separated from each other subsea, before liquid drilling fluid and solids being diverted and pumped to surface by the subsea pump. This was also envisioned by Gonzales in U.S. Pat. No. 6,276,455.
[0017] Thirdly as the subsea pump in earlier systems is in direct communication with the annulus, the return lines and the pump system must be of the same high pressure rating as the BOP itself. This put severe requirements on the pump system to handle internal pressures.
[0018] Subsea Choke Systems.
[0019] Prior art exists in an attempt to compensate for the excessive pressure in the borehole acting on the well when circulating out a kick in a conventional manner through high pressure small bore choke line and a surface choke on the upper part of this line. U.S. Pat. No. 4,046,191 (Neath) and U.S. Pat. No. 4,210,208 (Shanks) introduced a surface controlled subsea choke where the flow from below a closed Subsea BOP was directed into the main bore of the drilling riser through a subsea choke.
[0020] Neath envisioned a conventional drilling system where the riser was full of conventional weighted drilling fluid. If such a system was used in a situation where dual gradient drilling technology was used, the pressure on the downstream of the adjustable choke could become too high due to the high mud weight used. Also since the riser was initially full of drilling mud, gas introduced into the base of the riser at great water depth could introduce further problems since the riser have limited collapse and internal pressure ratings.
SUMMARY OF THE INVENTION
[0021] In order to overcome challenges with prior art in conducting well control operations during riserless drilling and other dual gradient drilling technology, a method of controlling wellbore pressure in a controlled fashion will be explained.
[0022] Several alternatives for creating a subsea separation system within a subsea BOP will be explained below. Reference numbers refer to the accompanying drawings, as examples only.
[0023] Subsea BOP Gas Separation System
[0024] A riser joint used may be particularly designed to function as a separator where the separated gas is vented to the surface via the riser and the liquid is pumped to the surface via an exterior return path from the main drilling riser ( FIG. 2 and FIG. 3 ). The main difference here with prior art is that the mud/liquid level in the riser is controlled and located at a considerable level below the sea level. In this fashion it is prevented that drilling fluids or liquids will be unloaded from the top of the riser if gas is being released into the base of the riser.
[0025] In another embodiment, a BOP extension joint (BOP-EJ) located between lower and upper annular preventer is so designed that with 2 different BOP elements closed, a chamber or cavity will be formed where gas can be separated from liquids by gravity and the separated gas vented via a conventional choke line or a separate conduit line, or alternatively via a riser to the surface. The liquid is pumped to the surface by the subsea mud pump controlling the liquid level in the cavity.
[0026] Another alternative would be a separate unit for separation where the separated gas is vented via a conventional choke line and the liquid is pumped to the surface through a separate liquid conduit line (not shown here).
[0027] A representation of a new riserless drilling system is shown in FIG. 4 . In this system a subsea mud pump 11 is installed on seabed or some distance above and hydraulically connected to the well so that the drilling fluid and drill cuttings are pumped up to the drilling installation in a separate return flow path 12 . The interphase between the drilling fluid and the seawater is then somewhere in the vicinity of the Subsea BOP.
[0028] BOP-Extension Joint vs. Riser Joint for Mud/Gas Separation
[0029] A conventional subsea BOP is normally equipped with two annular preventers on modern rigs. The lower annular preventer 16 in FIG. 1 a is normally the uppermost closing element in the lower BOP stack 3 which consists of a series of ram type preventers stacked on top of each other 15 a, b, c, d and the said BOP stack 3 installed with a special connector either to a High Pressure Wellhead (HP WH) 52 or a Horizontal Christmas-Tree (HXT) (not shown here). The total height of the lower subsea BOP is in the vicinity of 7 to 10 meter. The height of the HP WH is approximately 1 meter. The HP WH is normally installed on what is defined as the surface casing which normally sticks 2-3 meter above the seabed. The upper annular preventer 19 is normally installed in what is termed the Lower Marine Riser Package (LMRP). However, some rigs may have both annular preventers above the riser BOP disconnect point 20 , FIG. 1 b , in the LMRP. The interface between the lower BOP stack and the LMRP is normally designed a hydraulic remote operated disconnect point between the lower marine riser package (riser) and the lower subsea BOP. Hence the distance between the lower annular preventer on the BOP and the upper annular preventer in the LMRP is normally approximately 1.5-2.5 meters. In order to create a longer distance between the 2 annular preventers an extension joint could be installed to create more space.
[0030] If the mud and gas could be separated in a BOP cavity and/or BOP Extension Joint thereby creating a gas phase in the upper part of the BOP, this would allow a surface choke to control the gas pressure if connected to the cavity between the two closing elements, hydraulically either by flexible or fixed lines (no gas vent through riser).
[0031] BOP-Extension Joint can then be used for fluid-mud/gas separation in drilling with and without the riser.
[0032] If and when using the Low Riser Return System in another embodiment of this invention, the upper annular preventer can be closed during a drill pipe connection to avoid fluid level adjustment in the riser where in this case, the fluid level in the choke line is used to control and regulate the annulus pressure in order to compensate for the equivalent circulating density (ECD) effect (time saving). This is also explained in WO2009/123476, belonging to the applicant. The downside of having the liquid separated from the gas close to seabed as opposed to higher up in the riser is the longer pump suction line needed in deep water and the higher differential pressure capacity of the subsea pump system.
[0033] Another feature of this arrangement is the possibility to control bottom hole pressure while drilling (lower annular open) and when circulation out a well kick (lower annular closed), by controlling the liquid mud level in the choke line (subsea choke fully open) ( FIG. 6 ). In this case the upper annular could be substituted with a rotating BOP (RBOP or RCD) 19 where the mud pressure in the borehole annulus 1 is regulated by the liquid mud level in the choke line 51 ( FIG. 6 ). The pressure in the BOP and or BOP extension is now a function of the liquid level 51 in the choke line and the gas/air pressure above. This gas can either be ventilated to atmospheric pressure or controlled and regulated by the surface choke 22 . This will create a softer and more dynamic process than having the pump suction pressure (only liquid) directly controlling the wellbore pressure. When low compressibility liquid is contained in a closed loop system, it will create a very stiff system. Small changes will affect well bore pressure immediately, while a level control of drilling fluid, mud and/or seawater in the choke line will be a slower and more controllable process.
[0034] While drilling, this could set up a unique method of pressure control. An influx into the borehole between the open hole and drillstring could have a self regulating effect. An influx into the wellbore has a density higher than air in top of the choke line and for the case of example 8½″ hole and 6″ drill collars would have a capacity of minimum 17.8 litre per meter hole section. The capacity of most choke lines (3″-5) is between 4.56 litre per meter to 12.6 litre per meter. An influx of a certain magnitude would increase the level in the smaller capacity choke line to a higher level than the influx constitute in the openhole—drillstring annulus, hence an influx progressing would be stopped just by the higher hydrostatic pressure created by a higher liquid level 51 in the choke line 17 .
BRIEF DESCRIPTION OF DRAWINGS
[0035] FIG. 1 a illustrates a conventional subsea drilling system in normal drilling operations
[0036] FIG. 1 b illustrates conventional subsea drilling system in well control mode
[0037] FIG. 2 illustrates a first embodiment of the present invention, including a riser, in drilling mode.
[0038] FIG. 3 illustrated the embodiment of FIG. 2 in well control mode.
[0039] FIG. 4 illustrates a second riserless embodiment of the present invention in drilling mode.
[0040] FIG. 5 illustrates the embodiment of FIG. 4 in well control mode.
[0041] FIG. 6 illustrates the system of FIGS. 4 and 5 performing an alternative method for well control.
DETAILED DESCRIPTION OF THE INVENTION
[0042] FIG. 2 illustrates a first embodiment of the subsea drilling system of the invention. It comprises a well having a well bore 1 . The well bore may be partially cased. Above the seabed level 2 is arranged a subsea BOP 3 with a BOP extension joint 3 a which is equipped with several pressure sensors and several inlets and outlets. A riser 4 is connected to the BOP and extends to a vessel 5 above the sea level 6 . The riser 4 has a slip joint 7 to accommodating heave of the vessel 5 and a riser tensioning system 7 a , 7 b . Above the diverter housing and diverter outlet is a low pressure gas stripper installed 53 to prevent low pressure gas escaping to the drill floor of the drilling rig. The diverter line 36 is ventilated to the atmosphere or the mud gas separator (not shown). The flow line valve 35 is closed as the drilling fluid now is returned via the subsea pump 11 and return line 12 .
[0043] Drill string 8 extends from a top drive 9 on the platform 5 and into the well bore 1 . The lower end the drill string 8 is equipped with a drill bit 10 .
[0044] A liquid return line 12 is connected to the BOP extension 3 a at a first side port 13 and extends to the water surface. The liquid return line has a subsea lift pump 11 for aiding mud return to the surface vessel 5 . The liquid return line has a valve 49 in the branch between the first side port 13 and the pump 11 .
[0045] A gas return line 17 is also connected to the BOP 3 or BOP extension 3 a by a second side port 18 . The gas return line 17 extends to the water surface and drilling vessel 5 . The gas return line has a first valve 21 close to the second side port 18 and a choke valve 22 near the water surface 6 or on the drilling unit. Both the liquid return line 12 and the gas return line 17 are at their upper ends connected to a collection tank 23 via a mud gas separator 42 on the drilling rig.
[0046] The BOP has a main bore 14 through witch the drill string 8 extends. A plurality of safety valves 15 , rams 15 a , 15 b , 15 c , are adapted to close the main bore 14 around the drilling tubular or to seal the wellbore completely 15 d , to prevent a blow-out.
[0047] Above the safety valves 15 and below the first side port 13 the BOP 3 has a lower annular valve 16 , which is adapted to close around the drilling tubulars 8 .
[0048] The BOP has an upper annular valve 19 above the second side port 18 . This annular valve may be a so-called rotating BOP, enabling drilling while the valve is closed.
[0049] A by-pass line 24 extends from the lower BOP (here two side ports 25 and 26 are shown) below the lower annular valve 16 to a third side port 27 between the first and the second side ports 13 and 18 . The by-pass also has a branch 29 connecting to the gas return line 17 here defined as the gas line or choke line. The bypass line 24 has lower valves 28 to close off the lower part of the by-pass line 24 , a first upper valve 30 to close off the branch 29 and a second upper valve 31 to close off the connection to the port 27 . In addition, there is a choke valve 32 in this bypass line.
[0050] The system also has a kill line 33 , which is also included in a conventional system.
[0051] At the top of the riser is a mudflow line 34 with a flow line valve 35 and a overboard line (diverter) 36 with a valve 37 , which are also according to a conventional system.
[0052] As also according to a conventional system, there are several mud pumps 38 pumping mud from the collection tank 23 to the top drive 9 through a line 39 . A valve 40 is included in the line 39 close to the top drive.
[0053] In addition, there is a booster line 41 extending from a mud pump 38 to a fourth side port 42 in the Lower Marine Riser Package or a circulating line connected below the first side port 13 . The line 41 is equipped with at least 1 valve 50 close to the side port 42 . This can be a backpressure valve and or a 2 way shut-off valve. This line may also be used to inject low density fluid or gas into the return path downstream the subsea choke valve installed close to the subsea BOP.
[0054] The system as described above in connection with FIG. 2 is basically the same for all the embodiments described hereinafter. In the following only the items deviating from the arrangement in FIG. 2 will be described in detail.
[0055] The system of FIG. 2 can be used for drilling with and without marine drilling riser. FIG. 4 shows a system without a riser. Except for the lack of a riser, the system is identical with the system described in FIG. 2 .
[0056] The operation of the system according to the invention will now be described:
[0057] FIG. 2 illustrates normal drilling mode of the system. During normal drilling with a riser, both the lower and upper annular valves 16 , 19 in the BOP 3 are open. The mud level 45 in the BOP or BOP extension or riser is controlled using the subsea mud lift pump 11 , which is hydraulically connected to the lower part of the BOP extension joint or riser. Any drill gas or background gas is vented off through the marine drilling riser, i.e. through the gas vent line 36 . Suspended and small gas bubbles may for the most case follow the liquid mud phase into the pump system 11 and be pumped to the surface. At surface the returns can be directed to the shale shakers 43 directly or via a valve 47 to the mud gas separator 42 . The system allows the mud level 45 to be adjusted for control of the bottom hole pressure. The fluid above the mud in the riser can be any type of liquid or gas, including air.
[0058] FIG. 3 shows the system in a well control event. The drill string rotation is stopped and the lower and upper annular valves 16 , 19 are closed. This creates a cavity 46 between the lower and upper annular valves 16 , 19 . The well fluid is diverted from below the lower annular valve 16 to below the upper annular valve 19 , i.e. to within the cavity 46 , through the bypass line 24 containing the choke valve 32 . Separation of the fluids in the cavity 46 in the BOP extension joint will take place due to gravity. The outlet 13 to the subsea lift pump 11 is arranged below the inlet level 27 for the well fluid, and the gas is vented off to the surface through the choke or gas return line 17 connected to the outlet 18 located above the fluid inlet 27 from the well. Normally, the gas/liquid interface level 45 will be located below the level for the gas line 17 . A surface choke 22 is used to control the pressure of the gas phase. The level 45 in the BOP cavity can be measured either by pressure transducers, gamma densitometries, sound, or other methods.
[0059] In this circulation and well pressure control method the surface drill pipe pressure can be regulated by regulating the subsea choke 32 , the subsea pump 11 can be used to regulate the liquid level 45 in the BOP cavity and the pressure in the cavity can be regulated by the pressure in the surface choke 22 , pressure in the BOP cavity, or the liquid level 51 in FIG. 6 (or combination of the two).
[0060] FIGS. 4 and 5 show riserless drilling, and well control mode in riserless drilling, respectively.
[0061] During riserless drilling, the annular valves 16 , 19 in the BOP 3 are open as illustrated in FIG. 4 . The mud/sea water level 45 in the BOP 3 is controlled using the subsea mud lift pump 11 and pressure sensors in the extension joint 3 a between the two annulars 16 , 19 . Any small amount of drill gas or background gas may escape to sea from the open top of the BOP extension. However, most of the drill gas will follow the return liquids through the pump system 11 . In a well control event, the drill string 8 rotation is stopped and the lower and upper annular valves 16 , 19 are closed, as illustrated in FIG. 5 . The well fluid is diverted from below the lower annular 16 to below the upper annular valve 19 through the bypass line 24 containing the choke valve 32 . The choke valve 32 will now control the bottom hole pressure and the pressure downstream the choke 32 will be much lower than the upstream pressure. This will improve the separation process.
[0062] Separation of the fluids in the BOP extension joint 3 a will take place due to gravity. An outlet 13 to the subsea lift pump 11 is arranged below the inlet level 27 for well fluid, and any free gas is vented off to surface through the flexible or fixed choke line 17 to above the water surface. Normally, the gas/fluid level 45 will be located below the outlet level 18 for the vent line 17 . A surface choke 22 is used to control the pressure of the gas phase.
[0063] FIG. 6 illustrates the subsea separator in an alternative mode. Here the subsea choke 32 is used to control bottom-hole pressure (BHP). The separator with the vent line 17 is used to remove the gas from the liquid before entering the subsea lift pump. However, the liquid is allowed to enter the vent line 17 and establish a liquid/gas interface 51 in the vent line 17 . The head of this liquid column and any pressure above the liquid/gas interface defines the pressure in the separator cavity 46 . By regulating the pressure above the fluid level and the level of the interface 51 , the pressure in the cavity 46 can be adjusted as illustrated in FIG. 6 .
[0064] The pressure in the cavity 46 can be increased by pumping mud from the surface through the boost line 41 . This will quickly raise the interface 51 and hence increase the pressure in the cavity 46 . The pressure in the cavity 46 can be lowered by increasing the pump rate of the subsea return pump 11 . This will quickly reduce the level of the interface 51 and hence the pressure in the cavity 46 . This provides a means for rapidly adjusting the pressure in the cavity 46 and hence the back pressure against the well fluid entering the cavity 46 from the by-pass line 24 if the choke is fully open.
[0065] In the case of a subsea pump failure or as an option, a low density fluid or gas may be injected into the return lines or choke line, downstream of the subsea choke valve, so as to keep the pressure immediately downstream the subsea choke valve 32 substantially lower than the pressure upstream the subsea choke valve. In this manner the well pressure can be controlled accurately by the subsea choke.
[0066] Means to Reduce Pressure Fluctuations:
[0067] In order to avoid slug flow and large pressure variations, a choke valve 32 can be used to control the flow of fluids into the separator 48 and avoid or reduce the pressure fluctuations. Pressure fluctuation downstream of the subsea choke valve 32 could also affect the upstream pressure of the subsea choke (well pressure). However, keeping the gas/fluid level within the separator allows large gas flow rates to the handled.
[0068] Increasing the diameter of the choke line (6-8 inches) allows the liquid to enter the vent line 17 and separate from the gas without excessive pressure fluctuation in the BOP cavity. Since a subsea choke valve reduces the pressure, a low pressure choke line may be used.
[0069] In an effective riserless subsea separation system, the liquid/gas interface level may be kept within the separator and a surface choke valve to control the separator pressure may be introduced.
[0070] When keeping the pressure in the separator equal to or just below the ambient seawater pressure, the normal drilling operations can be conducted without major adjustments to the separator pressure. With only gas in the choke line, the size can be reduced (2-3 inches). This system will also reduce the gas separated from the liquid before entering the subsea lift pump. The pressure will reduce the subsea pump differential pressure needed to bring the return fluid back to the drilling vessel. Gas bleed off may take place at high rates.
[0071] This means that the remaining gas still contained in the liquids has to be separated at surface. So, the gas from the choke line, and the mud and gas from the subsea lift pump can be diverted through the mud gas separator/Poor Boy degasser 42 and vented off through the vent line in the derrick. | A subsea mud pump can be used to return heavy drilling fluid to the surface. In order to provide a less stringent requirement for such a pump and to better manage the bottom hole pressure in the case of a gas kick or well control event, the gas should be separated from the drilling fluid before the drilling fluid enters the subsea mud pump and the pressure within the separating chamber. The mud pump suction should be controlled and kept equal or lower than the ambient seawater pressure. This can be achieved within the cavities of the subsea BOP by a system arrangement and methods explained. This function can be used with or without a drilling riser connecting the subsea BOP to a drilling unit above the body of water. | 4 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to agricultural machinery and soil drainage. More specifically, the present invention pertains to a new drain tile roll support and loading apparatus for replacing and dispensing drain tile rolls while in the field.
BACKGROUND OF THE INVENTION
[0002] Tile drainage is a subsurface water control means often utilized in agricultural settings for improvement of moisture levels within the soil. Moisture content within the soil is often controlled in order to improve crop growth and for allowing access to the crops by way of heavy farm equipment. Too much moisture in the soil inhibits plant growth, and heavily saturated soil can quickly bog down heavy machinery utilized in crop cultivation, making access difficult.
[0003] Tile drainage has been performed with a buried drain pipe that is either segmented or perforated to accept therein subsurface water, wherein the buried drain is graded such that the water naturally flows in one direction and into a surface water collection area, such as a nearby body of water or a man-made reservoir. The drain tile is an elongated section of pipe that is buried within an excavated trench within the soil, in a similar fashion as a French drain around buildings, wherein the drain tile is then optionally covered with gravel and then a layer of soil thereover. As the water level rises, or as water percolates into the soil from rainfall, the water enters the pipe and flows from the farm fields and away from the crops, which desire a specific range of moisture levels in order to ensure proper root growth for healthy development.
[0004] Deploying drain tile, or “stringing” tile, involves placement of a drain tile piping roll onto a tractor or similar article of farm machinery for support thereof Workmen may draw the tile from a spool supporting the roll as the tractor advances along a desired path for the drain tile trench. The spool rotates and the length of tile is withdrawn from the roll for placement into the trench before backfilling with soil thereover. The roll is therefore rotatably supported by the tractor to facilitate withdrawing therefrom, while periodic replacement of the roll is required after its drain tile length is fully deployed. In the past, when replacing the roll of drainage tile, the operator had to position a new roll onto a spool shaft and secure the roll thereto using an upper and lower spool ring that ensures the roll does not slide from the spool during operation. During the process of stringing tile in the field, operators were often required to exit the vehicle cab in which they are loading a fresh roll of drain tile onto the spool shaft or when unloading a depleted roll therefrom. This process was time-consuming and inefficient to the overall tile stringing process.
[0005] The replacement process further allowed for steps to be skipped that affect safety of the operators and workers in the field. During replacement of the roll, both rings of the spool were often required to be installed to contain the roll thereon. If operators choose not to install the removable top ring, the tile might dislodge from the spool and flip over as it is being unrolled, which could cause defects in the pipe. The tile might also bounce along the spool shaft while in the field, causing damage to the spool, the tile, and the trailer. It has been submitted in the past that an effective solution to these known problems was necessary. A solution was proposed in U.S. patent application Ser. No. 13/866,263, Publication No. 20130277488 (published Oct. 24, 2013) (Paul Hovland, applicant), which patent application is incorporated herein in its entirety by this reference. This system utilizes a pivoting rocker arm 20 for placing the cap, which provides for only a single location of the upper ring 13 when it is oriented to be opposing the ring 12 . Additionally, the system refers to controls in the vehicle and shows multiple sets of hydraulic hoses, which suggest a configuration where there is the capability for independent manual cylinder control for each hydraulically adjusted portion of the implement.
[0006] The present invention pertains to an automatic apparatus for and method of placing and replacing rolls of drainage tile onto a mobile spool of a hydraulic tile stringing implement, and for adjusting the vertical size of the spool during removal of the tile from the spool.
[0007] Consequently, there exists a need for improved methods and apparatuses for efficiently deploying rolls of drainage tiles.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an easily implemented efficient system and method for placing and replacing rolls of drainage tiles.
[0009] It is a feature of the present invention to utilize a fully automated system for control of a tile stringing implement from within the vehicle.
[0010] It is an advantage of the present invention to provide for a reduction in time necessary to load and deploy a roll of drainage tile on a tile stringing implement.
[0011] It is another object of the invention to reduce the potential for unwanted movement of tile within the spool while tile is being removed from the spool.
[0012] It is another feature to provide a vertically adjustable height of the hat of the spool to make the vertical size of the spool variable to reflect variations in coiling of the tile, construction of the tile and even during dispensing of the tile with the declining amount of tile remaining on the spool. Hat travel when capping a coil is often limited by both the surface of the coil end as well as a “core”. The core is a larger diameter plastic tile sleeve the same width as the coil, onto which the tile is wrapped at the manufacturer. Thus, the hat has limited travel even when the amount of tile is declining. However, the fresh coil ends are sometimes uneven (nonplanar) with bulging internal coil loops. The present invention is often capable of compressing this to a planar surface. However, if it cannot, then it has the ability to preload down pressure and urge it to become planar as the tile is unwound.
[0013] It is another advantage of the present invention to reduce the freedom for unwanted motion of the tile while on the spool.
[0014] The present invention is an apparatus and method for efficiently and cost effectively deploying rolls of drainage tiles in the field.
[0015] Accordingly, the present invention is a method of adjusting a spool size for a coil of drainage tile on a drainage tile stringing implement attachment comprising the steps of: providing a coil of an elongated drainage tile, said coil having a first height characteristic; providing a spool shaft oriented in a first direction and said coil being disposed about said spool shaft; providing a first spool end drainage tile retaining member, coupled to said spool shaft; providing a second spool end drainage tile retaining member; providing a spool shaft receiving member coupled to said second spool end drainage tile retaining member; translating said second spool end drainage tile retaining member in a second direction, which is substantially parallel with said first direction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention may be more fully understood by reading the following description of the preferred embodiments of the invention, in conjunction with the appended drawing wherein:
[0017] FIG. 1 is an elevation view of the drainage tile stringing implement attachment 100 of the present invention, shown in an empty and mostly vertical compact configuration.
[0018] FIG. 2 is an elevation view of the drainage tile stringing implement attachment 100 of FIG. 1 in an empty and less vertically compact configuration.
[0019] FIG. 3 is an elevation view of the drainage tile stringing implement attachment 100 of FIGS. 1 and 2 in a coil engaging configuration.
[0020] FIG. 4 is an elevation view of the drainage tile stringing implement attachment 100 of FIGS. 1-3 , in a loaded and upright configuration.
[0021] FIG. 5 is an elevation view of the drainage tile stringing implement attachment 100 of FIGS. 1-4 , in a loaded, upright and capped configuration.
[0022] FIG. 6 is an alternate view of the system shown in FIGS. 1-5 with alternate numbering and additional numbering relating to the hydraulic portions of the present invention which are also shown in FIGS. 7-11 .
[0023] FIG. 7 is a hydraulic circuit diagram of an embodiment of the present invention.
[0024] FIG. 8 is a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 2 , wherein the arrows represent the direction of fluid flow.
[0025] FIG. 9 is a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 3 , wherein the arrows represent the direction of fluid flow.
[0026] FIG. 10 is a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 4 , wherein the arrows represent the direction of fluid flow.
[0027] FIG. 11 is a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 5 , wherein the arrows represent the direction of fluid flow.
DETAILED DESCRIPTION
[0028] Although described with particular reference to three point hitch implement, the system and method for tile stringing can be implemented in with many different types of devices, the particular implement shown here is merely an example of the many other implements that could utilize the present invention. The materials and construction techniques used in the fabrication of the present invention are common and well known in the art of agricultural implements. A person skilled in the art of design and fabrication of agricultural implements would readily understand how to make and use this invention after reading this application and viewing the drawings.
[0029] Now referring to the Figures, wherein like numerals refer to like matters throughout, and more particularly referring to FIG. 1 , there is shown a drainage tile stringing implement attachment 100 of the present invention, it is not shown attached to any type of vehicle but this embodiment may be attached to a three point hitch trailer of the type commonly pulled by tractors. However, drainage tile stringing implement attachment 100 could be attached to a regular automotive trailer, a truck, a UTV, an ATV, a cart, or the like. Drainage tile stringing implement attachment 100 is shown having a spool shaft 111 , a first spool end drainage tile retaining member 112 and a second spool end drainage tile retaining member 113 , where the spool shaft 111 extends between the first spool end drainage tile retaining member 112 and the second spool end drainage tile retaining member 113 . These items may be, but need not be, similar to items 11 , 12 and 13 , respectively, in the above referenced published US Patent Application. Spool shaft 111 is shown in a generally upright position and having a shaft longitudinal axis which is shown as being temporarily substantially vertical. First spool end drainage tile retaining member 112 coupled to and disposed about spool shaft 111 and is preferably capable of being pivoted so that the spool shaft 111 is in a substantially horizontal orientation. ( FIG. 3 ). Second spool end drainage tile retaining member 113 is coupled to spool shaft receiving member 114 , which is coupled to reaching support arm 120 , which is coupled to upstanding frame member top portion 152 , which is coupled to upstanding frame member bottom portion 150 . Upstanding frame member bottom portion 150 having a bottom portion longitudinal axis and upstanding frame member top portion 152 having a top portion longitudinal axis which is substantially parallel with said bottom portion longitudinal axis. Upstanding frame member bottom portion 150 and upstanding frame member top portion 152 are configured in a nested telescoping arrangement, however other non-nested configurations are contemplated as well. Said bottom portion longitudinal axis is shown as being substantially vertical, but variations of this are also contemplated. Upstanding frame member top portion 152 is coupled to a powered telescoping actuator second portion 122 , which is coupled to powered telescoping actuator first portion 121 , which in combination may be a hydraulic cylinder or other powered linear actuator, such as a pneumatic cylinder or an electric or mechanical linear actuator or suitable substitute. When hydraulic pressure is applied to powered telescoping actuator second portion 122 , it moves and forces upstanding frame member top portion 152 to telescope to an expanded configuration, such as is shown in FIG. 2 . Also shown in FIG. 1 is a spool shaft receiving member side portion 1413 with a spool shaft receiving member first interior member 1411 and a spool shaft receiving member second interior member 1415 . Spool shaft 111 is shown having a spool shaft top portion 1111 which is disposed between spool shaft receiving member second interior member 1415 and spool shaft receiving member first interior member 1411 . Said spool shaft 111 having a substantially cylindrical intermediate portion disposed between said spool shaft top portion 1111 and a point of connection between first spool end drainage tile retaining member 112 and spool shaft 111 .
[0030] Now referring to FIG. 2 , there is shown view of the drainage tile stringing implement attachment 100 of the present invention with upstanding frame member top portion 152 being powered into an extended configuration with respect to upstanding frame member bottom portion 150 . This results in the second spool end drainage tile retaining member 113 and spool shaft receiving member 114 being elevated above spool shaft top portion 1111 . This cap raising step is done before the next step which is shown in FIG. 3 .
[0031] Now referring to FIG. 3 , there is shown a coil engaging configuration where the spool shaft 111 is shown in a substantially horizontal configuration for insertion in a central opening of a coil of an agricultural drainage tile. First spool end drainage tile retaining member 112 is shown coupled to shaft supporting pivot arm 140 which is forced into a pivoted position by application of hydraulic pressure to powered pivoting actuator second portion 142 , or the like, which is coupled to powered pivoting actuator first portion 141 , or the like, which is coupled to a structural portion of drainage tile stringing implement attachment 100 . This construction and function of the items described in these paragraphs may be, but need not be, similar to items performing similar functions in the above referenced US published patent application.
[0032] Now referring to FIG. 4 , there is shown a configuration of the drainage tile stringing implement attachment 100 which has been retracted into an uncapped and loaded configuration. Note that the powered pivoting actuator second portion 142 and powered pivoting actuator first portion 141 are omitted from this figure, but it should be understood that they were used in combination with each other to tip the coil of drainage tile into the shown orientation.
[0033] Now referring to FIG. 5 , there is shown a configuration of the drainage tile stringing implement attachment 100 where the second spool end drainage tile retaining member 113 has been lowered by manipulation of powered telescoping actuator second portion 122 and powered telescoping actuator first portion 121 so that second spool end drainage tile retaining member 113 contacts the top portion of a coil of drainage tile disposed about spool shaft 111 . It should be noted that spool shaft top portion 1111 is shown below spool shaft receiving member second interior member 1415 , which is between spool shaft receiving member first interior member 1411 and spool shaft top portion 1111 . This configuration shows that the second spool end drainage tile retaining member 113 is being prohibited from going down to the most compact configuration of FIG. 1 by the presence of the coil of drainage tile. As drainage tile is removed from the coil (depending on how it was wound and how the wound coil was oriented with respect to the spool shaft 111 ), a cap may appear between the second spool end drainage tile retaining member 113 and the top of the coil. In one embodiment of the present invention, the hydraulic pressure on powered telescoping actuator second portion 122 can be changed and upstanding frame member top portion 152 may be retracted into upstanding frame member bottom portion 150 and the gap could be reduced or eliminated. The spool shaft receiving member side portion 1413 in some embodiments might be longer so as to permit an extended range of penetration or variable depth of penetration of the spool shaft 111 into spool shaft receiving member 114 . This ability to change the vertical height of the spool which is formed when second spool end drainage tile retaining member 113 is moved toward first spool end drainage tile retaining member 112 allows for a size characteristic of the spool to be adjustable and to thereby facilitate secure retention and use of partial coils of drainage tile and allows for reducing the space which might permit unwanted movement of the drainage tile within the drainage tile stringing implement attachment 100 . The control of the precise location of the second spool end drainage tile retaining member 113 , with respect to the spool shaft 111 could be left to the judgement of a human operator or vehicle drivers.
[0034] Now referring to FIG. 6 , there is shown an alternate view of the system shown in the position as shown in FIG. 1 with alternate numbering and additional numbering relating to the hydraulic portions of the present invention, which are also shown in FIGS. 7-11 . More specifically, powered telescoping actuator first portion 121 and powered telescoping actuator second portion 122 are collectively labelled as hat lift cylinder 3 in FIG. 6 . Similarly, powered pivoting actuator first portion 141 and powered pivoting actuator second portion 142 are collectively labeled as table lift cylinder 4 in FIG. 6 . Note the table lift cylinder is not shown in FIGS. 1, 2, 4, and 5 , but it should be understood that it would be present in an actual working embodiment of the present invention.
[0035] Now referring to FIG. 7 , there is a close up view of the hydraulic circuit of the present invention which includes a hydraulic pump 1 , which could be powered by an Option A dc power unit, or an Option B tractor hydraulics or suitable substitutes. A hydraulic flow control push button control 2 (which could be disposed within reach of the driver of a vehicle and could be either electrical for Option A or a Tractor Valve if Option B). The Hat Lift Cylinder 3 and the Table Lift Cylinder 4 are also shown. Also shown is Sequencing Valve 5 with associated connections to button 2 and cylinders 3 and 4 .
[0036] Now referring to FIG. 8 , there is shown a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 2 , wherein the arrows represent the direction of fluid flow.
[0037] Now referring to FIG. 9 , there is shown a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 3 , wherein the arrows represent the direction of fluid flow.
[0038] Now referring to FIG. 10 , there is shown a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 4 , wherein the arrows represent the direction of fluid flow.
[0039] Now referring to FIG. 11 , there is shown a hydraulic flow diagram which corresponds to the system configuration shown in FIG. 5 , wherein the arrows represent the direction of fluid flow.
[0040] In operation, and now referring to FIGS. 1-5 and 8-11 , the system of the present invention could function as follows: the system starts from a transport configuration with the spool empty and the second spool end drainage tile retaining member 113 seated as far down as possible ( FIG. 1 ). Next the second spool end drainage tile retaining member 113 is raised up to allow for pivoting of the spool shaft 111 ( FIGS. 2 and 8 ). Next the spool shaft 111 is pivoted to allow mating with a coil of drainage tile ( FIGS. 3 and 9 ). Next the spool shaft 111 is pivoted upright ( FIGS. 4 and 10 ). And lastly, the second spool end drainage tile retaining member 113 is lowered into close proximity of the top portion of the coil of drainage tile ( FIGS. 5 and 11 ). From the tractor or truck seat, the operator while viewing the implement, manipulates the push button or lever to cycle the loading system. The cycle is stopped (at FIG. 3 ) to maneuver the spool shaft into the fresh coil. After the spool shaft and coil are fully engaged, the button or lever is actuated to continue the loading cycle. At the end of the loading cycle, the operator can stop the capping process when 113 contacts the coil or then may continue lowering, thereby adding the desired down pressure or completely seats the cap, whichever comes first.
[0041] It should be understood that while this invention could have benefits of automated operation, many of the benefits of the invention could still be enjoyed with simple separate manual hydraulic controls for each hydraulic cylinder. Our automated sequencing not only simplifies the cycling process, it also protects the implement's components. Our system will not allow the table to pivot while the spool shaft ( 111 ) is engaged with 113 or allow the coil or 111 to contact the 113 while loading.
[0042] In the above description, it should be understood that the claimed means for translating might include only a linear actuator and some simple control mechanism. This could be a single hydraulic cylinder with a manual hydraulic controller, together with the required hoses, fluid, connections, and sources of hydraulic power. Alternatively, this means for translating could be electric and could be many different types of linear actuators, including, but not limited to, an electric motor and a treaded or toothed elongated member together with a simple switch, or suitable substitutes. Of course, the means for translating could include the system as shown in FIGS. 6-11 .
[0043] It should be understood that when the terms vertical and horizontal are used to describe the present invention, it is not intended that these terms be interpreted to make them incorrect if the present invention is on a vehicle which is on uneven ground or inclined. The terms are meant to encompass such variations.
[0044] It is thought that the method and apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form, construct steps and arrangement of the parts and steps thereof without departing from the spirit and scope of the invention or sacrificing all of their material advantages. The form herein described is merely a preferred exemplary embodiment thereof. | A drainage tile stringer system which includes a spool which has an automated hat, which translates along the stinger or shaft of the spool so that the vertical size of the spool is adjustable to accommodate differences in coils of drainage tiles. The system is automated so that a single controller can be utilized to perform all of the hydraulic functions required to load a coil onto the drainage tile stringer system and to adjust the vertical spool dimension. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of International Application No. PCT/JP2014/071652 filed on Aug. 19, 2014, which claims priority to Japanese Application No. 2013-172239 filed on Aug. 22, 2013.
[0002] The Contents of International Application No. PCT/JP2014/071652 and Japanese application No. 2013-172239 are hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0003] The present invention relates to an objective optical system and, more particularly, to an endoscope objective optical system to be applied to a medical endoscope.
BACKGROUND ART
[0004] As a medical endoscope, it is preferable to acquire an image of a high resolution and a wide angle of observation field, while ensuring low invasive to the patient. However, high image quality and less invasive are opposite to each other. Specifically, in order to obtain a high quality image, it is necessary to increase the number of pixels, and it is preferable to use a large imaging element. On the other hand, as the size of the imaging element increases, the imaging lens diameter becomes large, and as a result, the external diameter becomes larger, it makes it difficult to ensure the less invasiveness.
[0005] Therefore, in recent years, the pixel pitch is made smaller, the number of pixels is increased without increasing the size of the imaging element, a method for obtaining high quality images are becoming the mainstream. The pixel pitch has been becoming smaller and smaller as time goes and imaging elements having a pixel pitch of a few microns or less have also been developed.
[0006] For example, Patent Literature 1 and Patent Literature 2 disclose an objective optical system adapted to the miniaturized imaging element with the above-described pixel pitch which is several microns or less.
CITATION LIST
Patent Literature
[0000]
{PTL 1} Japanese Unexamined Patent Application, Publication No. 2007-249189
{PTL 2} Japanese Unexamined Patent Application, Publication No. 2011-247949
SUMMARY OF INVENTION
[0009] One aspect of the present invention is an endoscope objective optical system including at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions,
[0000] 15.0<ν A−ndA< 15.75 (1)
[0000] −0.2> rdyA 1/ ih>− 20 (2)
[0010] wherein νA is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a cross-sectional view of the overall structure of an objective optical system according to a first embodiment of the present invention.
[0012] FIG. 2 is a cross-sectional view of the overall structure of an objective optical system according to a second embodiment of the present invention.
[0013] FIG. 3 is a cross-sectional view of the overall structure of an objective optical system according to a third embodiment of the present invention.
[0014] FIG. 4 is a cross-sectional view of the overall structure of an objective optical system according to Example 1 of the present invention.
[0015] FIG. 5 shows graphs of aberrations of the objective optical system according to Example 1 of the present invention.
[0016] FIG. 6A depicts cross-sectional views of the overall structure of an objective optical system according to Example 2 of the present invention when the optical system is in a normal view state.
[0017] FIG. 6B depicts cross-sectional views of the overall structure of an objective optical system according to Example 2 of the present invention when the optical system is in a magnified view state.
[0018] FIG. 7 shows graphs of aberrations in the normal view state in the objective optical system according to Example 2 of the present invention.
[0019] FIG. 8 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 2 of the present invention.
[0020] FIG. 9A depicts cross-sectional views of the overall structure of an objective optical system according to Example 3 of the present invention when the optical system in a normal view state.
[0021] FIG. 9B depicts cross-sectional views of the overall structure of an objective optical system according to Example 3 of the present invention when the optical system is in a magnified view state.
[0022] FIG. 10 shows graphs of aberrations in the normal view state in the objective optical system according to Example 3 of the present invention.
[0023] FIG. 11 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 3 of the present invention.
[0024] FIG. 12A depicts cross-sectional views of the overall structure of an objective optical system according to Example 4 of the present invention when the optical system is in a normal view state.
[0025] FIG. 12B depicts cross-sectional views of the overall structure of an objective optical system according to Example 4 of the present invention when the optical system is in a magnified view state.
[0026] FIG. 13 shows graphs of aberrations in the normal view state in the objective optical system according to Example 4 of the present invention.
[0027] FIG. 14 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 4 of the present invention.
[0028] FIG. 15 is a cross-sectional view of the overall structure of an objective optical system according to Example 5 of the present invention.
[0029] FIG. 16 shows graphs of aberrations of the objective optical system according to Example 5 of the present invention.
[0030] FIG. 17 is a cross-sectional view of the overall structure of an objective optical system according to Example 6 of the present invention.
[0031] FIG. 18 shows graphs of aberrations of the objective optical system according to Example 6 of the present invention.
[0032] FIG. 19A depicts cross-sectional views of the overall structure of an objective optical system according to Example 7 of the present invention when the optical system is in a normal view state.
[0033] FIG. 19B depicts cross-sectional views of the overall structure of an objective optical system according to Example 7 of the present invention when the optical system is in a magnified view state.
[0034] FIG. 20 shows graphs of aberrations in the normal view state in the objective optical system according to Example 7 of the present invention.
[0035] FIG. 21 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 7 of the present invention.
[0036] FIG. 22 is a cross-sectional view of the overall structure of an objective optical system according to Example 8 of the present invention.
[0037] FIG. 23 shows graphs of aberrations of the objective optical system according to Example 8 of the present invention.
[0038] FIG. 24 is a cross-sectional view of the overall structure of an objective optical system according to Example 9 of the present invention.
[0039] FIG. 25 shows graphs of aberrations of the objective optical system according to Example 9 of the present invention.
[0040] FIG. 26 is a cross-sectional view of the overall structure of an objective optical system according to Example 10 of the present invention.
[0041] FIG. 27 shows graphs of aberrations of the objective optical system according to Example 10 of the present invention.
[0042] FIG. 28 is a cross-sectional view of the overall structure of an objective optical system according to Example 11 of the present invention.
[0043] FIG. 29 shows graphs of aberrations of the objective optical system according to Example 11 of the present invention.
[0044] FIG. 30 is a cross-sectional view of the overall structure of an objective optical system according to Example 12 of the present invention.
[0045] FIG. 31 shows graphs of aberrations of the objective optical system according to Example 12 of the present invention.
[0046] FIG. 32A depicts cross-sectional views of the overall structure of an objective optical system according to Example 13 of the present invention when the optical system is in a normal view state.
[0047] FIG. 32B depicts cross-sectional views of the overall structure of an objective optical system according to Example 13 of the present invention when the optical system is in a magnified view state.
[0048] FIG. 33 shows graphs of aberrations in the normal view state in the objective optical system according to Example 13 of the present invention.
[0049] FIG. 34 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 13 of the present invention.
[0050] FIG. 35A depicts cross-sectional views of the overall structure of an objective optical system according to Example 14 of the present invention when the optical system is in a normal view state.
[0051] FIG. 35B depicts cross-sectional views of the overall structure of an objective optical system according to Example 14 of the present invention when the optical system is in a magnified view state.
[0052] FIG. 36 shows graphs of aberrations in the normal view state in the objective optical system according to Example 14 of the present invention.
[0053] FIG. 37 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 14 of the present invention.
[0054] FIG. 38A depicts cross-sectional views of the overall structure of an objective optical system according to Example 15 of the present invention when the optical system is in a normal view state.
[0055] FIG. 38B depicts cross-sectional views of the overall structure of an objective optical system according to Example 15 of the present invention when the optical system is in a magnified view state.
[0056] FIG. 39 shows graphs of aberrations in the normal view state of the objective optical system according to Example 15 of the present invention.
[0057] FIG. 40 shows graphs of aberrations in the magnified view state in the objective optical system according to Example 15 of the present invention.
DESCRIPTION OF EMBODIMENTS
First Embodiment
[0058] An objective optical system according to a first embodiment of the present invention will be described below with reference to the drawings.
[0059] FIG. 1 is a cross-sectional view of the overall structure of the objective optical system. As shown in FIG. 1 , the objective optical system includes a front lens group GF, an aperture stop S, and a rear lens group GR in this order from an object.
[0060] The front lens group GF includes a negative first lens L 1 and a positive second lens L 2 in this order from the object-side plane, and has positive refracting power. The rear lens group GR includes a parallel flat plate F and a cemented lens CL 1 (first cemented lens) formed by joining a positive third lens L 3 and a negative fourth lens L 4 , and has positive refracting power.
[0061] The cemented lens CL 1 is formed so as to satisfy the following conditional expression (1) and conditional expression (2).
[0000] 15.0<ν A−ndA< 15.75 (1)
[0000] −0.2> rdyA 1/ ih>− 20 (2)
[0062] In the expression, νA is an Abbe number of the negative lens of the cemented lens CL 1 , ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of the joining surface of the negative lens of the cemented lens CL 1 , and ih is an image height.
[0063] When the upper limit of the conditional expression (1) is exceeded, the refractive index of the negative lens is too small to achieve necessary negative refracting power. In order to achieve negative refracting power, the curvatures of the joining surface and the air-contacting surface need to be increased, which undesirably causes, in particular, non-axial aberration. When the lower limit of the conditional expression (1) is exceeded, the Abbe number of the negative lens is too small, which leads to a state in which axial and non-axial chromatic aberration can be easily caused.
[0064] Furthermore, when the upper limit of the conditional expression (2) is exceeded, the curvature of the cemented lens becomes too small and hence the color correction effect of the cemented lens becomes lessened, which leads to a state in which axial and non-axial chromatic aberration can be easily caused. When the lower limit of the conditional expression (2) is exceeded, the curvature of the cemented lens becomes too large, which leads to a state in which axial and non-axial chromatic aberration can be easily caused.
[0065] Therefore, it is more preferable that the conditional expression (1)′ and the conditional expression (2)′ below or the conditional expression (1)″ and the conditional expression (2)″ below are adopted, as substitute for the conditional expression (1) and the conditional expression (2).
[0000] 15.3<ν A−ndA< 15.7 (1)′
[0000] −1.0> rdyA 1/ ih>− 5.0 (2)′
[0000] 15.5<ν A−ndA< 15.6 (1)″
[0000] −1.2> rdyA 1/ ih>− 2.5 (2)″
[0066] The negative fourth lens L 4 of the cemented lens CL 1 is formed so as to satisfy the following conditional expression (3).
[0000] −0.2>( rdyA 1+ rdyA 2)/( rdyA 1− rdyA 2)>−10 (3)
[0067] In the expression, rdyA2 is the curvature radius of the air-contacting surface of the negative lens of the cemented lens CL 1 .
[0068] The conditional expression (3) is a conditional expression regarding the shape factor of the negative fourth lens L 4 of the cemented lens CL 1 . As a result of the negative fourth lens L 4 of the cemented lens CL 1 satisfying the conditional expression (3), axial and non-axial chromatic aberration can be corrected while still achieving necessary negative refracting power. When the upper limit of the conditional expression (3) is exceeded, the curvature radius of the joining surface becomes too small, which may make the processing difficult. In addition, because the curvature of the positive third lens L 3 of the cemented lens CL 1 also becomes large, it becomes difficult to secure a sufficient thickness of the positive third lens L 3 at the periphery thereof. When the lower limit of the conditional expression (3) is exceeded, the curvature radius of the joining surface becomes too large, which makes it difficult to correct axial and non-axial chromatic aberration.
[0069] For this reasons above, it is more preferable that the conditional expression (3)′ or the conditional expression (3)″ below are adopted, as substitute for the conditional expression (3).
[0000] −0.3>( rdyA 1+ rdyA 2)/( rdyA 1− rdyA 2)>−3.0 (3)′
[0000] The following conditional expression is still more preferable.
[0000] −0.4>( rdyA 1+ rdyA 2)/( rdyA 1− rdyA 2)>−2.5 (3)″
[0070] It is preferable that in the objective optical system according to this embodiment, the negative lens is disposed most closely to the object-side plane, like the first lens L 1 of the front lens group GF in FIG. 1 , and the negative lens disposed most closely to the object-side plane is configured so as to satisfy the following conditional expression (4).
[0000] −3.0≦ rdy 12/ rdyA 1<−0.2 (4)
[0071] In the expression, rdy12 is the image-side curvature radius of the negative first lens.
[0072] The conditional expression (4) is a conditional expression for the image-side curvature radius of the negative first lens L 1 and the curvature radius of the cemented lens CL 1 . By satisfying the conditional expression (4), it is possible to favorably maintain the balance between the image-side curvature radius of the negative first lens L 1 and the curvature radius of the cemented lens CL 1 , making it possible to favorably correct comatic aberration, field curvature, axial chromatic aberration, and chromatic aberration of magnification. However, when the upper limit of the conditional expression (4) is exceeded, the curvature radius of the negative first lens L 1 becomes large, which may worsen comatic aberration, field curvature, and distortion. Furthermore, when the lower limit of the conditional expression (4) is exceeded, the curvature radius of the cemented lens CL 1 becomes too large, which makes it difficult to correct axial chromatic aberration and chromatic aberration of magnification.
[0073] Therefore, it is more preferable that the conditional expression (4)′ or the conditional expression (4)″ below are adopted, as substitute for the conditional expression (4).
[0000] −2.5≦ rdy 12/ rdyA 1<−0.3 (4)′
[0000] −2.0≦ rdy 12/ rdyA 1<−0.39 (4)″
[0074] Furthermore, the cemented lens CL 1 is configured to satisfy the following conditional expression (5).
[0000] 1.0< DB/DA< 10 (5)
[0000] 0.1< DA/ih< 2.0 (6)
[0075] In the expression, DA is the thickness at the middle of the negative fourth lens L 4 of the cemented lens CL 1 , and DB is the thickness at the middle of the positive third lens L 3 of the cemented lens CL 1 .
[0076] The conditional expression (5) and the conditional expression (6) are conditional expressions regarding the thickness at the middle of the cemented lens CL 1 . By satisfying the conditional expression (5) and the conditional expression (6), it becomes possible to achieve an objective optical system with an appropriate overall length in which the lenses do not easily exhibit manufacturing defects, such as fracture and cracks.
[0077] When the upper limit of the conditional expression (5) is exceeded, the thickness at the middle of the negative fourth lens L 4 of the cemented lens CL 1 becomes too small, which may easily cause fracture or cracks. When the lower limit of the conditional expression (5) is exceeded, the thickness at the middle of the positive third lens L 3 of the cemented lens becomes too small, which makes it difficult to secure a sufficient thickness at the periphery thereof and hence drastically degrades the ease of processing.
[0078] When the upper limit of the conditional expression (6) is exceeded, the thickness at the middle of the negative fourth lens L 4 becomes too large, causing the overall length to be undesirably large. When the lower limit of the conditional expression (6) is exceeded, the thickness at the middle of the negative fourth lens L 4 becomes too small, which may cause fracture or cracks.
[0079] Therefore, it is more preferable that the conditional expression (5)′ and the conditional expression (6)′ below or the conditional expression (5)″ and the conditional expression (6)″ below are adopted, as substitute for the conditional expression (5) and the conditional expression (6).
[0000] 2.5< DB/DA< 7.5 (5)′
[0000] 0.15< DA/ih< 1.0 (6)′
[0000] The following conditional expression is still more preferable.
[0000] 4.0< DB/DA< 4.5 (5)″
[0000] 0.2< DA/ih< 0.7 (6)″
[0080] Furthermore, the negative first lens L 1 disposed most closely to the object-side plane and the negative lens of the cemented lens CL 1 are configured to satisfy the following conditional expression.
[0000] 0.5< PW 1/ PW 4<10 (7)
[0081] In the expression, PW1 is the refracting power of the negative first lens, and PW4 is the refracting power of the negative lens of the cemented lens.
[0082] The conditional expression (7) is a conditional expression for the refracting power of the negative first lens L 1 and the refracting power of the negative fourth lens L 4 of the cemented lens CL 1 . By satisfying the conditional expression (7), it is possible to favorably maintain the balance between the refracting power of the negative first lens L 1 and the refracting power of the negative third lens L 3 in the cemented lens CL 1 , making it possible to favorably correct comatic aberration, field curvature, axial chromatic aberration, and chromatic aberration of magnification. When the upper limit of the conditional expression (7) is exceeded, the refracting power of the negative first lens L 1 becomes too intense, worsening comatic aberration, field curvature, and distortion. When the lower limit of the conditional expression (7) is exceeded, the refracting power of the negative fourth lens L 4 of the cemented lens CL 1 becomes too intense, making it difficult to correct axial chromatic aberration and chromatic aberration of magnification.
[0083] Therefore, it is more preferable that the conditional expression (7)′ or the conditional expression (7)″ below are adopted, as substitute for the conditional expression (7).
[0000] 1.5< PW 1/ PW 4<5.0 (7)′
[0000] 1.58< PW 1/ PW 4<3.0 (7)″
[0084] The negative first lens disposed most closely to the object-side plane is configured to satisfy the following conditional expression (8).
[0000] 0.5<( rdy 11+ rdy 12)/( rdy 11− rdy 12)<1.7 (8)
[0085] In the expression, rdy11 is the object-side curvature radius of the negative first lens, and rdy12 is the image-side curvature radius of the negative first lens.
[0086] The conditional expression (8) is a conditional expression regarding the shape factor of the negative first lens L 1 . By satisfying the conditional expression (8), the necessary negative refracting power can be achieved. When the lower limit of the conditional expression (8) is exceeded, the refracting power of the negative first lens L 1 decreases. When the upper limit of the conditional expression (8) is exceeded, the lens productivity drastically decreases.
[0087] Therefore, it is more preferable that the conditional expression (8)′ or the conditional expression (8)″ below is adopted, as substitute for the conditional expression (8).
[0000] 0.7<( rdy 11+ rdy 12)/( rdy 11− rdy 12)<1.3 (8)′
[0000] The following conditional expression is still more preferable.
[0000] 0.99<( rdy 11+ rdy 12)/( rdy 11− rdy 12)<1.01 (8)″
[0088] The cemented lens CL 1 is configured to satisfy the following conditional expression (9).
[0000] 0.05<( rdyB 1+ rdyB 2)/( rdyB 1− rdyB 2)<2.0 (9)
[0089] In the expression, rdyB1 is the curvature radius of the air-contacting surface of the positive third lens L 3 in the cemented lens CL 1 , and rdyB2 is the curvature radius of the joining surface of the positive third lens L 3 in the cemented lens CL 1 .
[0090] The conditional expression (9) is a conditional expression regarding the shape factor of the positive third lens L 3 of the cemented lens CL 1 . By satisfying the conditional expression (9), an appropriate curvature radius can be obtained, making it possible to secure a sufficient thickness at the periphery of the lens while still ensuring the necessary positive refracting power. When the upper limit or the lower limit of the conditional expression (9) is exceeded, either one of the curvature radii becomes too small and a sufficient thickness at the periphery thereof cannot be ensured, making manufacturing thereof considerably difficult.
[0091] Therefore, it is more preferable that the conditional expression (9)′ or the conditional expression (9)″ below is adopted, as substitute for the conditional expression (9).
[0000] 0.1<( rdyB 1+ rdyB 2)/( rdyB 1− rdyB 2)<0.5 (9)′
[0000] 0.13<( rdyB 1+ rdyB 2)/( rdyB 1− rdyB 2)<0.45 (9)″
[0092] As described above, according to this embodiment, it is possible to make the objective optical system capable of acquiring an image having high precision and a wide angle of observation field by satisfactorily correcting various aberrations while ensuring low invasiveness.
[0093] Although the above-described embodiment has been described by way of an example where the rear lens group GR is configured to include the one cemented lens CL 1 , the rear lens group GR may be provided with a plurality of cemented lenses. In addition, both of the front lens group GF and the rear lens group GR may be configured to include the cemented lens.
Second Embodiment
[0094] An objective optical system according to a second embodiment of the present invention will be described below with reference to the drawings.
[0095] FIG. 2 is a cross-sectional view of the overall structure of the objective optical system. As shown in FIG. 2 , the objective optical system includes a first lens group G 1 , an aperture stop S, a second lens group, and a third lens group G 3 in this order from an object.
[0096] The first lens group G 1 includes the negative first lens L 1 , the parallel flat plate F, the positive second lens L 2 , and the first cemented lens CL 1 formed by joining the positive third lens L 3 and the negative fourth lens L 4 in this order from the object, and has positive refracting power.
[0097] The second lens group G 2 includes a cemented lens CL 2 formed by joining a negative fifth lens L 5 and a positive sixth lens L 6 , and has negative refracting power. Furthermore, the second lens group G 2 is movable along the optical axis, and it is possible to switch between a normal view and a magnified view by moving the second lens group G 2 .
[0098] The third lens group G 3 includes a positive seventh lens L 7 , a cemented lens CL 3 formed by joining a positive eighth lens L 8 and a negative ninth lens L 9 , and the parallel flat plate F, and has positive refracting power.
[0099] The objective optical system according to this embodiment is also configured to satisfy the conditional expressions (1) through (9) in the above-described first embodiment. In this case, it is sufficient if at least one of the cemented lens CL 1 and the cemented lens CL 2 is configured to satisfy each conditional expression.
[0100] Furthermore, the objective optical system according to this embodiment is configured to satisfy the following conditional expression (10).
[0000] 1< FL 2 G×Δ 2 G/FL 2 <200 (10)
[0101] In the expression, Δ2G is the absolute value of the displacement of the second lens group from a normal view to a close-up magnified view, FL is a focal length of the entire objective optical system in a normal view, and FL2G is a focal length of the second lens group.
[0102] The conditional expression (10) is a conditional expression regarding the displacement of the second lens group G 2 from the normal view to the close-up magnified view. By satisfying the conditional expression (10), an appropriate displacement can be performed and a focus range in accordance with a technician's intuition can be realized. When the upper limit of the conditional expression (10) is exceeded, the displacement is too large, causing the overall length to become undesirably large. When the lower limit of the conditional expression (10) is exceeded, the focus changes with a small displacement, degrading the usability of the system by a technician.
[0103] Because of this, it is more preferable that the conditional expression (10)′ or the conditional expression (10)″ below are adopted, as substitute for the conditional expression (10).
[0000] 3< FL 2 G×Δ 2 G/FL 2 <10 (10)′
[0000] 4.4< FL 2 G×Δ 2 G/FL 2 <6.0 (10)″
Third Embodiment
[0104] An objective optical system according to a third embodiment of the present invention will be described below with reference to the drawings.
[0105] FIG. 3 is a cross-sectional view of the overall structure of the objective optical system. As shown in FIG. 3 , the objective optical system includes a first lens group G 1 , a second lens group, an aperture stop S, and a third lens group G 3 in this order from an object.
[0106] The first lens group G 1 includes the negative first lens L 1 , the parallel flat plate F, and the positive second lens L 2 in this order from the object, and has positive refracting power.
[0107] The second lens group G 2 includes the positive third lens L 3 movable at the time of focusing so that it is possible to switch between a normal view and a magnified view by moving the second lens group G 2 .
[0108] The third lens group G 3 includes the cemented lens CL 1 formed by joining the positive fourth lens L 4 and the negative fifth lens L 5 , the cemented lens CL 2 formed by joining the positive sixth lens L 6 and the negative seventh lens L 7 , and the parallel flat plate F, and has positive refracting power.
[0109] The objective optical system according to this embodiment is also configured to satisfy the conditional expressions (1) through (9) in the above-described first embodiment. In this case, it is sufficient if at least one of the cemented lens CL 1 and the cemented lens CL 2 is configured to satisfy each conditional expression.
EXAMPLES
[0110] Next, Examples 1 to 15 of the objective optical system according to any one of the embodiments described above will be described with reference to FIGS. 4 to 33 . In the lens data described in each of the examples, r is the radius of curvature (mm), d is the axial distance (mm), Nd represents a refractive index at the d-line, and Vd represents the Abbe number at the d-line.
Example 1
[0111] FIG. 4 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 1 of the present invention, FIG. 5 shows aberration charts, and lens data of the objective optical system according Example 1 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.20
1.88300
40.76
2
0.462
0.27
3
∞
0.03
4
3.254
1.05
1.83400
37.16
5
−1.041
0.07
6
aperture stop
0.03
7
∞
0.60
1.52100
65.12
8
∞
0.10
9
2.124
0.85
1.75500
52.32
10
−0.804
0.30
1.95906
17.47
11
−2.068
0.38
12
∞
0.50
1.51633
64.14
13
∞
0.01
1.00000
64.00
14
∞
0.50
1.00000
50.49
15
∞
Various data
Focal length
0.67
FNO.
5.00
Angle of observation field 2ω
133.48
Focal length of each group
Front group
Rear group
2.25
1.93
Example 2
[0112] FIG. 6 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 2 of the present invention, FIGS. 7 and 8 show aberration charts, and lens data of the objective optical system according Example 2 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.158
0.85
3
∞
0.40
1.52100
65.12
4
∞
0.20
5
−3.355
1.70
1.58144
40.75
6
−2.430
0.30
7
5.659
0.80
1.51742
52.43
8
−1.284
0.30
1.92286
18.90
9
−2.002
0.05
10
aperture stop
0.03
11
∞
D11
12
∞
0.30
1.77250
49.60
13
1.216
0.55
1.72825
28.46
14
3.618
0.10
15
∞
D15
16
4.765
1.15
1.81600
46.62
17
−6.127
0.05
18
3.997
1.53
1.61800
63.33
19
−2.843
0.35
1.95906
17.47
20
8.733
0.09
21
∞
0.10
22
∞
0.40
1.52300
58.59
23
∞
0.75
24
∞
0.75
1.51633
64.14
25
∞
0.01
1.51300
64.01
26
∞
0.65
1.50510
63.26
27
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.15
1.40
FNO.
6.06
7.39
Angle of observation
159.91
90.36
field 2ω
Various data
D11
0.31
1.71
D15
1.72
0.32
Focal length of each group
First group
Second group
Third group
1.94
−4.17
3.09
Example 3
[0113] FIG. 9 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 3 of the present invention, FIGS. 10 and 11 show aberration charts, and lens data of the objective optical system according Example 3 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.148
0.85
3
∞
0.40
1.52100
65.12
4
∞
0.20
5
−3.309
1.70
1.58144
40.75
6
−2.474
0.30
7
6.028
0.80
1.51742
52.43
8
−1.255
0.30
1.95906
17.47
9
−1.910
0.05
10
aperture stop
0.03
11
∞
D11
12
∞
0.30
1.77250
49.60
13
1.089
0.55
1.72825
28.46
14
3.739
0.10
15
∞
D15
16
4.574
1.15
1.81600
46.62
17
−6.626
0.05
18
3.758
1.53
1.61800
63.33
19
−2.858
0.35
1.95906
17.47
20
6.853
0.09
21
∞
0.10
22
∞
0.40
1.52300
58.59
23
∞
0.76
24
∞
0.75
1.51633
64.14
25
∞
0.01
1.51300
64.01
26
∞
0.65
1.50510
63.26
27
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.15
1.40
FNO.
6.21
7.49
Angle of observation
160.04
90.53
field 2ω
Various data
D11
0.31
1.71
D15
1.72
0.32
Focal length of each group
First group
Second group
Third group
1.91
−4.20
3.12
Example 4
[0114] FIG. 12 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 4 of the present invention, FIGS. 13 and 14 show aberration charts, and lens data of the objective optical system according Example 4 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.139
0.85
3
∞
0.40
1.52100
65.12
4
∞
0.20
5
−3.688
1.52
1.58144
40.75
6
−2.511
0.30
7
19.344
0.80
1.58144
40.75
8
−1.041
0.30
1.95906
17.47
9
−1.693
0.05
10
aperture stop
0.03
11
∞
D11
12
∞
0.30
1.77250
49.60
13
1.124
0.55
1.72825
28.46
14
3.702
0.10
15
∞
D15
16
4.569
1.15
1.81600
46.62
17
−6.842
0.05
18
3.908
1.53
1.61800
63.33
19
−2.836
0.35
1.95906
17.47
20
8.387
0.09
21
∞
0.10
22
∞
0.40
1.52300
58.59
23
∞
0.81
24
∞
0.75
1.51633
64.14
25
∞
0.01
1.51300
64.01
26
∞
0.65
1.50510
63.26
27
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.15
1.40
FNO.
6.20
7.53
Angle of observation
59.91
90.33
field 2ω
Various data
D11
0.31
1.71
D15
1.72
0.32
Focal length of each group
First group
Second group
Third group
1.92
−4.19
3.14
Example 5
[0115] FIG. 15 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 5 of the present invention, FIG. 16 shows aberration charts, and lens data of the objective optical system according Example 5 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.27
1.88300
40.76
2
0.427
0.36
3
22.369
0.30
1.88300
40.76
4
1.152
0.68
1.69895
30.13
5
−0.908
0.05
6
aperture stop
0.10
7
449.945
0.30
1.88300
40.76
8
1.223
0.82
1.48749
70.23
9
−1.385
0.05
10
1.912
1.06
1.72916
54.68
11
−0.884
0.30
1.95906
17.47
12
−1.771
0.05
13
∞
0.31
1.51400
85.67
14
∞
0.36
15
∞
0.30
1.51633
64.14
16
∞
0.01
1.51300
64.01
17
∞
0.40
1.50510
63.26
18
∞
Various data
Focal length
0.45
FNO.
3.00
Angle of observation field 2ω
159.51
Focal length of each group
Front group
Rear group
−43.52
1.33
Example 6
[0116] FIG. 17 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 6 of the present invention, FIG. 18 shows aberration charts, and lens data of the objective optical system according Example 6 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.25
1.88300
40.76
2
0.442
0.42
3
−5.140
0.70
1.69895
30.13
4
−0.900
0.05
5
∞
0.31
1.51400
85.67
6
∞
0.05
7
aperture stop
0.05
8
∞
0.25
1.88300
40.76
9
1.578
0.67
1.51633
64.14
10
−1.264
0.03
11
∞
0.03
12
∞
0.03
13
1.572
0.78
1.72916
54.68
14
−0.925
0.25
1.95906
17.47
15
−2.261
0.36
16
∞
0.30
1.51633
64.14
17
∞
0.52
1.50510
63.26
18
∞
Various data
Focal length
0.44
FNO.
2.99
Angle of observation field 2ω
162.55
Focal length of each group
Front group
Rear group
−10.3449
1.2124
Example 7
[0117] FIG. 19 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 7 of the present invention, FIGS. 20 and 21 show aberration charts, and lens data of the objective optical system according Example 7 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.30
1.88300
40.76
2
1.044
0.51
3
∞
0.40
1.52100
65.12
4
∞
0.19
5
−1.668
0.41
1.84666
23.78
6
−1.756
0.10
7
∞
0.01
8
∞
0.02
9
2.070
0.35
1.84666
23.78
10
2.000
0.07
11
∞
1.18
12
∞
0.20
13
aperture stop
0.10
14
6.829
0.50
1.88300
40.76
15
−2.715
0.31
1.71999
50.23
16
−5.630
0.31
17
2.888
0.89
1.72916
54.68
18
−1.087
0.30
1.95906
17.47
19
−2.708
0.32
20
∞
0.40
1.52300
58.59
21
∞
0.02
22
∞
1.00
1.51633
64.14
23
∞
0.00
1.51300
64.01
24
∞
0.65
1.50510
63.26
25
∞
Zoom data
Normal View state
Magnified view state
Focal length
0.64
0.62
FNO.
3.00
3.00
Angle of observation field
88.15
89.87
2ω
Various data
D7
0.01
1.41
D11
1.18
0.01
Focal length of each group
First group
Second group
Third group
−1.43
54.09
1.73
Example 8
[0118] FIG. 22 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 8 of the present invention, FIG. 23 shows aberration charts, and lens data of the objective optical system according Example 8 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.30
1.88300
40.76
2
0.427
0.52
3
2.314
0.30
1.88300
40.76
4
0.650
0.60
1.62004
36.26
5
−0.738
0.02
6
aperture stop
0.01
7
∞
0.55
8
1.578
0.60
1.72916
54.68
9
−0.800
0.20
1.95906
17.47
10
−2.029
0.38
11
∞
0.50
1.51633
64.14
12
∞
0.00
1.51300
64.01
13
∞
0.50
1.50510
63.26
14
∞
Various data
Focal length
0.48
FNO.
2.98
Angle of observation field 2ω
132.22
Focal length of each group
Front group
Rear group
2.55
1.65
Example 9
[0119] FIG. 24 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 9 of the present invention, FIG. 25 shows aberration charts, and lens data of the objective optical system according Example 9 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.30
1.88300
40.76
2
0.427
0.54
3
2.638
0.30
1.88300
40.76
4
0.650
0.60
1.62004
36.26
5
−0.729
0.02
6
aperture stop
0.01
7
∞
0.44
8
1.562
0.75
1.72916
54.68
9
−0.800
0.20
1.95906
17.47
10
−2.453
0.02
11
7.876
0.30
1.51633
64.14
12
−5.104
0.06
13
∞
0.50
1.51633
64.14
14
∞
0.00
1.51300
64.01
15
∞
0.50
1.50510
63.26
16
∞
D16
Various data
Focal length
0.44
FNO.
2.99
Angle of observation field 2ω
174.40
Focal length of each group
Front group
Rear group
2.49
1.53
Example 10
[0120] FIG. 26 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 10 of the present invention, FIG. 27 shows aberration charts, and lens data of the objective optical system according Example 10 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.20
1.88300
40.76
2
0.561
0.37
3
∞
0.31
1.51400
85.67
4
∞
0.03
5
∞
0.72
1.95906
17.47
6
−2.598
0.05
7
aperture stop
0.10
8
∞
0.20
1.88300
40.76
9
1.020
0.70
1.69680
55.53
10
−1.169
0.03
11
1.290
0.90
1.72916
54.68
12
−0.949
0.28
1.95906
17.47
13
−7.770
0.21
14
∞
0.30
1.51633
64.14
15
∞
0.42
1.50510
63.26
16
∞
Various data
Focal length
0.44
FNO.
2.98
Angle of observation field 2ω
161.78
Focal length of each group
Front group
Rear group
−1.57
1.02
Example 11
[0121] FIG. 28 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 11 of the present invention, FIG. 29 shows aberration charts, and lens data of the objective optical system according Example 11 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.20
1.88300
40.76
2
0.561
0.76
3
∞
0.40
1.95906
17.47
4
−2.691
0.05
5
aperture stop
0.17
6
∞
0.20
1.88300
40.76
7
1.020
0.70
1.69680
55.53
8
−1.135
0.03
9
1.269
0.90
1.72916
54.68
10
−0.949
0.28
1.95906
17.47
11
−22.869
0.21
12
∞
0.30
1.51633
64.14
13
∞
0.42
1.50510
63.26
14
∞
Various data
Focal length
0.44
FNO.
2.98
Angle of observation field 2ω
161.76
Focal length of each group
Front group
Rear group
−1.47
1.02
Example 12
[0122] FIG. 30 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 12 of the present invention, FIG. 31 shows aberration charts, and lens data of the objective optical system according Example 12 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.20
1.88300
40.76
2
0.558
0.80
3
−21.491
0.40
1.95906
17.47
4
−2.925
0.05
5
aperture stop
0.25
6
4.374
0.20
1.88300
40.76
7
1.019
0.70
1.69680
55.53
8
−1.346
0.03
9
1.331
0.90
1.72916
54.68
10
−0.980
0.28
1.95906
17.47
11
−36.237
0.21
12
∞
0.30
1.51633
64.14
13
∞
0.42
1.50510
63.26
14
∞
Various data
Focal length
0.45
FNO.
2.98
Angle of observation field 2ω
159.66
Focal length of each group
Front group
Rear group
−1.21
1.04
Example 13
[0123] FIG. 32 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 13 of the present invention, FIGS. 33 and 34 show aberration charts, and lens data of the objective optical system according Example 13 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.108
1.18
3
−2.043
1.57
1.72916
54.68
4
−2.391
0.05
5
5.855
1.03
1.77250
49.60
6
−2.460
0.34
1.92286
18.90
7
−4.244
0.20
8
aperture stop
0.03
9
∞
0.30
1.77250
49.60
10
1.358
0.50
1.59270
35.31
11
9.321
1.90
12
4.364
1.40
1.48749
70.23
13
−3.267
0.05
14
5.198
1.70
1.48749
70.23
15
−2.130
0.24
1.95906
17.47
16
−5.691
0.30
17
∞
0.03
18
∞
0.40
1.52300
28.59
19
∞
0.72
20
∞
0.75
1.51633
64.14
21
∞
0.01
1.51300
64.01
22
∞
0.65
1.50510
63.26
23
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.11
1.40
FNO.
7.62
7.37
Angle of observation field
159.99
90.11
2ω
Various data
D7
0.20
1.80
D11
1.90
0.30
Focal length of each group
First group
Second group
Third group
2.06
−5.03
3.37
Example 14
[0124] FIG. 35 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 14 of the present invention, FIGS. 36 and 37 show aberration charts, and lens data of the objective optical system according Example 14 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.108
1.16
3
−2.043
1.60
1.72916
54.68
4
−2.419
0.05
5
5.700
1.03
1.77250
49.60
6
−2.629
0.34
1.95906
17.47
7
−4.273
0.20
8
aperture stop
0.03
9
∞
0.30
1.77250
49.60
10
1.352
0.50
1.59270
35.31
11
9.392
1.90
12
4.363
1.40
1.48749
70.23
13
−3.271
0.05
14
5.197
1.70
1.48749
70.23
15
−2.130
0.24
1.95906
17.47
16
−5.686
0.30
17
∞
0.03
18
∞
0.40
1.52300
58.59
19
∞
0.72
20
∞
0.75
1.51633
64.14
21
∞
0.01
1.51300
64.01
22
∞
0.65
1.50510
63.26
23
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.11
1.40
FNO.
7.62
7.37
Angle of observation field
159.98
90.12
2ω
Various data
D7
0.20
1.80
D11
1.90
0.30
Focal length of each group
First group
Second group
Third group
2.06
−5.03
3.37
Example 15
[0125] FIG. 38 shows a cross-sectional view of the overall configuration of an objective optical system according to Example 15 of the present invention, FIGS. 39 and 40 show aberration charts, and lens data of the objective optical system according Example 15 is shown below.
[0000]
Lens data
Surface Number
r
d
Nd
Vd
1
∞
0.35
1.88300
40.76
2
1.108
1.17
3
−2.100
1.64
1.72916
54.68
4
−2.340
0.05
5
5.895
1.03
1.77250
49.60
6
−2.751
0.34
1.95906
17.47
7
−4.576
0.20
8
aperture stop
0.03
9
−17.951
0.30
1.77250
49.60
10
1.424
0.50
1.59270
35.31
11
22.538
1.90
12
4.648
1.40
1.48749
70.23
13
−3.193
0.05
14
5.299
1.70
1.48749
70.23
15
−2.130
0.24
1.95906
17.47
16
−5.590
1.38
17
∞
0.75
1.51633
64.14
18
∞
0.01
1.51300
64.01
19
∞
0.65
1.50510
63.26
20
∞
Zoom data
Normal View state
Magnified view state
Focal length
1.10
1.40
FNO.
7.55
7.32
Angle of observation field
159.99
90.12
2ω
Various data
D7
0.20
1.80
D11
1.90
0.30
Focal length of each group
First group
Second group
Third group
2.06
−5.05
3.40
[0126] The values according to the aforementioned expressions (1) through (10) are shown in Table 1 and Table 2.
[0000]
TABLE 1
EXAM-
EXAM-
EXAM-
EXAM-
EXAM-
PLE 1
PLE 2
PLE 3
PLE 4
PLE 5
EXAMPLE 6
EXAMPLE 7
EXAMPLE 8
EXAMPLE 9
νA − ndA
15.51
15.51
15.51
15.51
15.51
15.51
15.51
15.51
15.51
rdyA1/ih
−1.24
−2.47
−2.49
−2.47
−1.97
−2.06
−2.42
−1.78
−1.78
(rdyA1 + rdyA2)/
−2.27
−0.51
−0.41
−0.49
−2.99
−2.39
−2.34
−2.30
−1.97
(rdyA1 − rdyA2)
rdy12/rdyA1
−0.57
−0.41
−0.40
−0.40
−0.48
−0.48
−0.96
−0.53
−0.53
FL2G * 2Δ/f1{circumflex over ( )}2
—
4.48
4.52
4.48
—
—
155.21
—
—
DB/DA
2.83
4.37
4.37
4.37
3.53
3.12
2.96
3.00
3.75
DA/ih
0.46
0.30
0.30
0.30
0.67
0.56
0.67
0.45
0.45
PW1/PW4
2.97
1.68
1.59
1.69
4.56
3.59
1.76
3.09
2.72
(rdy11 + rdy12)/
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
(rdy11 − rdy12)
(rdyB1 + rdyB2)/
0.45
0.17
0.14
0.16
0.37
0.26
0.45
0.33
0.32
(rdyB1 − rdyB2)
[0000]
TABLE 2
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
10
11
12
13
14
15
νA − ndA
15.51
15.51
15.51
15.51
15.51
15.51
rdyA1/ih
−2.11
−2.11
−2.18
−1.85
−1.85
−1.85
(rdyA1 + rdyA2)/(rdyA1 − rdyA2)
−1.28
−1.09
−1.06
−2.20
−2.20
−2.23
rdy12/rdyA1
−1.69
−1.69
−1.75
−1.92
−1.92
−1.92
FL2G * 2Δ/f1{circumflex over ( )}2
—
—
—
5.91
5.91
6.03
DB/DA
3.27
3.27
3.27
7.00
7.00
7.00
DA/ih
0.61
0.61
0.61
0.21
0.21
0.21
PW1/PW4
1.81
1.64
1.67
2.93
2.93
2.96
(rdy11 + rdy12)/(rdy11 − rdy12)
1.00
1.00
1.00
1.00
1.00
1.00
(rdyB1 + rdyB2)/(rdyB1 − rdyB2)
0.15
0.14
0.15
0.42
0.42
0.43
[0127] The inventors have arrived at the following aspects of the invention.
[0128] One aspect of the present invention is an endoscope objective optical system including at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions,
[0000] 15.0<ν A−ndA< 15.75 (1)
[0000] −0.2> rdyA 1/ ih>− 20 (2)
[0129] wherein νA is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height.
[0130] According to this aspect, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected using at least the first cemented lens that has the positive lens and the negative lens and that satisfies the conditional expression (1) and the conditional expression (2) simultaneously.
[0131] In the above-described aspect, it is preferable that the negative lens of the first cemented lens satisfies the following conditional expression,
[0000] −0.2>( rdyA 1+ rdyA 2)/( rdyA 1− rdyA 2)>−10 (3)
[0132] wherein rdyA1 is a curvature radius of the joining surface of the negative lens of the first cemented lens, and rdyA2 is a curvature radius of an air-contacting surface of the negative lens of the first cemented lens.
[0133] By doing so, axial and non-axial chromatic aberrations can be corrected while still achieving the necessary negative refracting power.
[0134] It is preferable that the optical system of the above-described aspect has a front lens group, an aperture stop, and a rear lens group arranged in this order from an object, that the rear lens group has a positive refractive index, and that the first cemented lens is disposed in at least one of the front lens group and the rear lens group.
[0135] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced. In addition, a long back focus can be secured while still restraining the size in the lens radial direction. Furthermore, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected by providing the cemented lens in at least one of the front lens group and the rear lens group.
[0136] In the above-described aspect, it is preferable that the front lens group includes a negative lens and a positive lens arranged in this order from the object and that the rear lens group includes the first cemented lens.
[0137] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced. In addition, a long back focus can be secured while still restraining the size in the lens radial direction. In addition, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected by providing the cemented lens in the rear lens group.
[0138] In the above-described aspect, it is preferable that the rear lens group has a plurality of the first cemented lenses.
[0139] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced. In addition, a long back focus can be secured while still restraining the size in the lens radial direction. Furthermore, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected by providing the cemented lens in the rear lens group.
[0140] In the above-described aspect, it is preferable that the front lens group has a negative lens and a cemented lens formed by joining at least one positive lens and at least one negative lens arranged in this order from the object, that the rear lens group has a plurality of the cemented lenses, and that the first cemented lens is provided in at least one of the front lens group and the rear lens group.
[0141] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced. In addition, a long back focus can be secured while still restraining the size in the lens radial direction. Furthermore, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected by providing the cemented lens in the rear lens group.
[0142] In the above-described aspect, it is preferable that the front lens group has a negative lens and a cemented lens formed by joining at least one positive lens and at least one negative lens arranged in this order from the object, that the rear lens group has the cemented lens and a positive lens, and that at least one of the front lens group and the rear lens group has the first cemented lens.
[0143] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced. In addition, a long back focus can be secured while still restraining the size in the lens radial direction. Furthermore, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected by providing the cemented lens in the rear lens group. Furthermore, by providing the positive lens closest to the image side, the exit ray angle can be made gentle, thereby making it possible to correct shading favorably.
[0144] In the above-described aspect, it is preferable that the optical system includes a positive first lens group, a movable negative second lens group, and a positive third lens group arranged in this order from an object, that it is possible to switch between a normal view and a magnified view by moving the second lens group, and that the third lens group includes the at least one first cemented lens.
[0145] By doing so, the number of lenses of each group can be reduced, the overall length of the endoscope objective optical system can be shortened, and the cost can be reduced, while still ensuring a wide angle of observation field and making it possible to achieve a good focus between the range from the normal view to the magnified view.
[0146] In the above-described aspect, it is preferable that the optical system includes a negative first lens group, a second lens group movable at the time of focusing, and a positive third lens group arranged in this order from an object, that it is possible to switch between a normal view and a magnified view by moving the second lens group, and that the third lens group has the at least one first cemented lens.
[0147] By doing so, a variation in aberration at the time of focusing can be reduced while still ensuring a long back focus, making it possible to produce an objective optical system that is tolerant to manufacturing errors. In addition, axial chromatic aberration and chromatic aberration of magnification can be favorably corrected as a result of the at least one cemented lens being disposed in the third lens group. It is preferable that the second lens group has positive refracting power or negative refracting power.
[0148] In the above-described aspect, it is preferable that the negative first lens is disposed closest to the object and satisfies the following conditional expression,
[0000] −3.0< rdy 12/ rdyA 1<−0.2 (4)
[0149] wherein rdy12 is an image-side curvature radius of the negative first lens, and rdyA1 is a curvature radius of a joining surface of the negative lens of the first cemented lens.
[0150] The conditional expression (4) is a conditional expression for the image-side curvature radius of the negative first lens and the curvature radius of the cemented lens. By satisfying the conditional expression (4), it is possible to favorably maintain the balance between the image-side curvature radius of the negative first lens and the curvature radius of the cemented lens, making it possible to favorably correct comatic aberration, field curvature, axial chromatic aberration, and chromatic aberration of magnification.
[0151] In the above-described aspect, it is preferable that the first cemented lens satisfies the following conditional expressions,
[0000] 1.0< DB/DA< 10 (5)
[0000] 0.1< DA/ih< 2.0 (6)
[0152] wherein DA is a thickness at the middle of the negative lens in the first cemented lens, DB is a thickness at the middle of the positive lens in the first cemented lens, and ih is an image height.
[0153] The conditional expression (5) and conditional expression (6) are conditional expressions regarding the thickness at the middle of the cemented lens. By satisfying the conditional expression (5) and conditional expression (6), it is possible to achieve an endoscope objective optical system with an appropriate overall length in which the lenses do not easily exhibit manufacturing defects, such as fracture and cracks.
[0154] In the above-described aspect, it is preferable that the following conditional expression is satisfied,
[0000] 0.5< PW 1/ PW 4<10 (7)
[0155] Wherein, PW1 is a refracting power of the negative first lens, and PW4 is a refracting power of the negative lens in the first cemented lens.
[0156] By satisfying the conditional expression (7), it is possible to favorably maintain the balance between the refracting power of the negative first lens and the refracting power of the negative lens of the first cemented lens, making it possible to favorably correct comatic aberration, field curvature, axial chromatic aberration, and chromatic aberration of magnification.
[0157] In the above-described aspect, it is preferable that the following conditional expression is satisfied,
[0000] 0.5<( rdy 11+ rdy 12)/( rdy 11− rdy 12)<1.7 (8)
[0158] wherein rdy11 is an object-side curvature radius of the negative first lens.
[0159] The necessary negative refracting power can be obtained by satisfying the conditional expression (8).
[0160] In the above-described aspect, it is preferable that the following conditional expression is satisfied,
[0000] 0.05<( rdyB 1+ rdyB 2)/( rdyB 1− rdyB 2)<2.0 (9)
[0161] wherein rdyB1 is a curvature radius of an air-contacting surface of the positive lens in the first cemented lens, and rdyB2 is a curvature radius of a joining surface of the positive lens in the first cemented lens.
[0162] By satisfying the conditional expression (9), an appropriate curvature radius can be derived, and the thickness of the lens at the periphery thereof can be secured while still ensuring the necessary positive refracting power.
[0163] In the above-described aspect, it is preferable that the following conditional expression is satisfied,
[0000] 1< FL 2 G×Δ 2 G/FL 2 <200 (10)
[0164] wherein Δ2G is an absolute value of displacement of the second lens group from a normal view state to a close-up magnified view state, FL is a focal length of the entire objective optical system in the normal view state, and FL2G is a focal length of the second lens group.
[0165] By satisfying the conditional expression (10), an appropriate displacement can be performed and a focus stroke in accordance with technician's feeling can be realized.
ADVANTAGEOUS EFFECTS OF INVENTION
[0166] The aforementioned aspects affords an advantage in that an image having high precision and a wide angle of observation field can be obtained by favorably correcting various aberrations while ensuring low invasiveness.
REFERENCE SIGNS LIST
[0000]
G 1 first group
G 2 second group
L 1 first lens
L 2 second lens
L 3 third lens
L 4 fourth lens
L 5 fifth lens
L 6 sixth lens
L 7 seventh lens
CL 1 cemented lens | This endoscope objective optical system is capable of acquiring images of high resolution and wide angle of observation field, maintaining low invasiveness and appropriately correcting various aberrations. This optical system has at least a first cemented lens which has a positive lens and a negative lens, in which the cemented lens satisfies the following conditional expressions.
15.0<ν A−ndA <15.75 (1)
−0.2> rdyA 1/ ih >−20 (2)
νA is an Abbe number of the negative lens, ndA is a refractive index of the negative lens at the d-line, rdyA1 is a curvature radius of a joining surface of the negative lens, and ih is an image height. | 6 |
RELATED APPLICATIONS
[0001] This application claims priority based upon U.S. Provisional Patent Application Ser. No. 61/510,564 filed Jul. 22, 2011.
FIELD OF THE INVENTION
[0002] This invention relates to a collapsible portable habitable shelter structure. More particularly, the present invention relates to a structure that collapses into a small, compact configuration that is light, easily stored, easily transported, and can be folded out to become a structurally habitable shelter.
BACKGROUND OF THE INVENTION
[0003] Emergency type housing units have been desired for numerous applications. Typically the units are nothing more than steel shipping containers which are modified for the usage desired. They tend to be heavy, difficult to transport, provide very limited functional space, and not desirable as a living area. Increasing of the functional space has been crudely addressed by cutting out portions of the container and affixing multiple containers together. The appearance of the units has remained to be that of a shipping container or trailer, usually with the need to perform extensive work on the interior to make the unit functional. Further, a single unit typically does not supply sufficient space to accomplish the needed function as the containers are so narrow in width that two or more containers must be placed together to get a functional space. When multiple units are assembled, the need to prevent water and wind infiltration causes considerable additional work to be done by skilled craftsmen, with specialty products to seal the units and properly connect them, which materials are not always available.
[0004] Since the steel units are bulky, heavy in weight, difficult to store and transport is typically handling one unit at a time, with a crane needed to move the units. These difficulties restrict the usage and desirability of container type units.
[0005] The challenge and need was for a unit that was light weight and compact when not in use so that it may be efficiently stored and transported, that supplies an attractive, functional space, that is strong, water and wind resistant, as well as adaptable to weather conditions, adaptable easily to special needs, and could be installed without special supplies or skilled labor in minimal time periods.
DISCLOSURE OF THE INVENTION
[0006] The present invention is a transformable collapsible structure or unit with a rigid center core structure with a top portion, a base portion, a first and second end section, affixed to a welded aluminum extrusion frame structure, to which is connected multiple sections, being a first and a second roof section, a first and a second floor section, a first and a second exterior wall section, and multiple side wall sections. The sections fold out to form an enclosed space adjoining the center core structure on side creating a useable and habitable interior space. The structure is unexpectedly strong and resistant to wind and water infiltration by use of metal extrusions caps at all folding joints which are continuous and interlocking, thereby stopping water or wind infiltration. The points of connection between wall sections where a rotating joint is not needed use a metal extrusion with tongue and groove configuration being tight fitting and which provides structural strength and resistance to both water and wind infiltration.
[0007] The structure or unit is stored in a folded configuration and can be put into use by first leveling the closed unit, placing floor support beams, rotating the roof sections upward to allow the floor and wall sections to be rotated downward, resting the floor section on the floor beams, rotating the exterior wall sections vertical and connecting the roof section to the exterior wall section. The side wall sections are then swung out to connect to the roof section and exterior wall sections.
[0008] When the roof section, floor section, exterior wall section and side wall section are rotated into position, the continuous extended metal caps lock the extrusions together providing structural strength and resistance to wind and water infiltration.
[0009] The connections between the wall sections where the sections do not have a rotation joint have a continuous extruded metal cap which is of a tongue and groove type connection, between mating edges providing structural strength and resistance to water and air infiltration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] To further describe and obtain a fuller understanding of the nature and objectives of the invention, the accompanying drawings are provided in which like parts are given reference numerals.
[0011] FIG. 1 is a prespective of the collapsible portable shelter unit in a closed configuration for storage or transport.
[0012] FIG. 2 is a prespective showing the end of a collapsed unit without the end utility sections or cover in place.
[0013] FIG. 3 shows the frame structure of the center core section of the collapsible unit.
[0014] FIG. 4 shows the support and leveling unit at the corners of the center core section.
[0015] FIG. 5 is a prespective of the unit with the floor support beams being put into place.
[0016] FIG. 6 shows the motion of opening of the unit by rotating of the roof section.
[0017] FIG. 7 shows the floor section being rotated into place.
[0018] FIG. 8 shows the exterior wall section being rotated into an upright position.
[0019] FIG. 9 shows the motion of the side walls being rotated outward to interlock with the roof and exterior wall sections.
[0020] FIG. 10 shows a prespective of the unit with one side opened and locked into place.
[0021] FIG. 11 shows a prespective of the unit with both sides opened.
[0022] FIG. 12 a shows a detail of the interconnection for a rotating joint.
[0023] FIG. 12 b shows a detail of the edge interlock.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referencing FIG. 1 is a transformable rectangular collapsible portable unit in the collapsed state being one embodiment of the present invention, which forms a modular unit 10 which is approximately 30 inches in width at edge 16 with a length of approximately 18 feet at edge 19 , with height approximately 8 feet at edge 14 allowing three units to be placed side by side in a typical shipping container or tractor trailer. Different dimensions can be used to meet the intended need for the unit.
[0025] The modular unit 10 has a rigid central core frame 19 , composed of aluminum extrusions. The frame, FIG. 3 , has horizontal 56 and vertical 27 extrusions welded together to form a rectangle and two such rectangles are welded together with cross beam 28 extrusions. The result is a box beam frame that has greater strength than expected. With the attachment of base portion 26 , roof portion 25 , and the end sections 20 , 13 , the core provides support for the roof sections 25 , floor sections 22 , exterior wall sections 21 , and side wall sections 24 ; that are adhered to the core and fold out to form an interior space. At the end of the core, FIG. 1 , attached is an air conditioning unit 17 , which can provide both cooled or heated air to the interior space. An electrical storage cabinet 18 is also provided for any needed electrical equipment for power distribution. At the other end of the core, in other configurations a storage cabinet can be affixed. In this closed configuration, FIG. 1 , the unit 10 can be easily transported by a lift or wheeled with installation of wheels at each corner of the base portion.
[0026] FIG. 2 shows the exposed end of the modular unit. The central core end portion 20 is shown and adjacent to it, on each side, are multiple panels which fold out to transform the modular unit into an expanded useable shelter. The most exterior panel 23 is the extending roof sections, followed by the floor sections 22 , and then the exterior wall sections 21 . The inner most section is the side wall sections 24 . The roof 23 , floor 22 , exterior wall 21 and side wall 24 sections can rotate out to locking positions to create an interior space. The roof, floor, exterior wall and side wall sections are composite panels.
[0027] The preferred center core section FIG. 3 is a rigid frame of extruded aluminum vertical beams 27 welded together with horizontal extruded aluminum beams 28 , to create a box beam structure which provides high strength but is light in weight. However, the rigid frame can be configured in various shapes known in the art to provide rigid structures.
[0028] FIG. 1 shows supports 15 at each of the corners of the modular unit 10 . FIG. 4 shows the configuration of the support 15 , in detail. It consists of a base plate 29 a supporting leg 30 , supporting plates 32 and 31 to hold the core structure with a wrench 34 that can be inserted into the socket 33 to allow ratcheting or cranking of the supporting leg 30 to allow height and leveling adjustment of the modular unit both quickly and easily. Although this is the preferred embodiment numerous other known mechanisms can be used such as a multi-holed support through which a bolt is passed through to set heights at various discrete settings, or plates with threaded rods connected thereto which can be adjusted by rotating the threaded rod to adjust height.
[0029] When it is desired to employ the modular unit, the unit 10 is placed in a cleared area. This can be on stabilized ground, or any reinforced base such as gravel, concrete or asphalt, and the unit 10 is leveled using the supports 15 , to set the correct height and all corners are leveled. Support beams 37 are inserted as shown in FIG. 5 in receptacles 36 located along the base portion of the modular unit. At the other end of the beams 37 are plates with welded threaded rods which thread into the end of the beam 37 . The plate 40 is rotated until all the beams 37 are level and thereby perpendicular with the exterior wall surface 12 of the unit 10 .
[0030] FIG. 6 shows the modular unit 10 being opened. The exterior roof panel section 23 is rotated out approximately 90 degrees, away from the unit body. Two spring-loaded dampers 41 as shown in FIG. 6 assist in providing support to the roof section 23 . The exterior portion of the top of the core section 11 and the exterior surface 12 of the roof section 23 are preferably covered with a roofing material or other material, depending upon the use of the unit.
[0031] FIG. 7 shows the continued opening of the roof section 23 which allows the combined floor 22 and exterior wall 21 sections to be rotated outward to a resting position upon the supporting floor beams 37 . With the floor section 22 put into place the exterior wall section 21 is rotated vertically and the upper edge 61 interlocks with the exterior edge 62 of the roof section 23 . The detail of the interconnection of edges 61 and 62 is seen in FIG. 12 b . Additional interlocking can be accomplished with conventional locking mechanisms located along the exterior wall edge. With the roof edge 62 affixed to the exterior wall edge 61 , the side walls 24 can be folded out as shown in FIG. 9 , the edges 46 and 47 of which connect with the roof edge 48 and exterior wall edge 49 .
[0032] FIG. 10 shows the expanded configuration of one side of the modular unit 10 , and in FIG. 11 the modular unit has been completely opened. The roof, exterior wall and side wall sections are insulated composite panels comprised of an exterior panel, being a lightweight rust free material, a center core of a thermal resistant material, and an interior panel, all adhered together. In the preferred configuration the interior and exterior panels are aluminum with an interior core of expanded polystyrene foam or a polyurethane foam. The use of insulated panels provides temperature stability and the center core section, with the air conditioning/ventilation unit 17 provide both cooling and heating directly into the habitable interior space. The edges of the panels are capped with metal extrusions which provide the connecting functions between panel edges, either a rotating hinged connection as seen at connections 64 between base portion and floor section, or top portion and roof section 63 , or floor and exterior wall section 65 as shown in FIG. 8 , or an interlocking between roof section edge 62 and exterior wall section edge 61 as seen in FIG. 8 .
[0033] FIG. 12 a shows typical rotating connection wherein a top portion cross-section 25 and roof section cross-section 23 connected by an extrusion intersection with cross-section of the components. The two metal extrusion caps interlock by rotating about each other in a circular mating of a portion of the extrusion 71 of the roof top cap with a portion of the extrusion 72 of the roof section cap, locking the extrusions together creating a seal between extrusions. The result is a locking of the extrusions and panels to create a structure stronger than expected. Further, the connection stops water and wind infiltration through the joint.
[0034] In other configurations, at the tongue and groove connection, a sealant may be placed at the exterior of the connection to prevent water or wind infiltration. Preferably if sealant is used it should be placed after the connection between the sections are made to allow easier removal of the sealant when dissembling the unit.
[0035] FIG. 12 b shows the interlock connection used between the roof section 25 outer edge 62 and the upper edge 61 of the exterior wall 21 , which may also be used by the side wall section connecting with the exterior wall section or with the roof section edge. This tongue 74 and groove 73 connection interlock is a substantially continuous contact that provides a structural integrity for the frame of the opened structure that is stronger than expected. Further, the tongue and groove connection prevents water and air infiltration.
[0036] In the configuration shown in FIGS. 8 , 10 and 11 , one or more windows 44 or doors 45 can be provided in the exterior walls section or side walls sections, as well as pre-wiring the walls and interior core for electric, data, and plumbing services. In other configurations, the modular unit may have interior partitions installed at a later time, to be adjusted as the use of the unit requires. Kitchenette modules and bathroom modules can be added to the unit if those functions are desired.
[0037] Since the modular unit contains all needed components pre-installed, a minimally trained crew of two men can level and fully expand a modular unit, having it operational in 15 to 30 minutes, depending on the skill and experience of the crew.
[0038] In other configurations, the modular units have wheels located at each end of the rigid central core section which allows the units to be conveniently wheeled to and from storage to truck loading dock without special equipment or moved at the desired location prior to opening. While various exemplary aspects and embodiments have been shown or discussed herein, other modifications that may be employed are within the scope of the invention. Accordingly, the present invention is not limited to the configuration shown, and is intended to embrace all such attention modifications or variations that fall within the spirit and scope of the appended claims.
[0039] Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a traditional word in a claim. | A collapsible portable shelter unit when in the collapsed mode is light and compact to make transport and storage convenient, but when opened provides an enclosed space that can be used for various purposes, which has an integrated high strength structured frame by the action of the interlocking extrusions which also provide resistance to water and wind infiltration. As needed, exterior windows and doors, air conditioning, electrical supply and other customization as required by the users' needs. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a female fitting and the pipe connection in which a male fitting is engaged in said female fitting, the engagement ensuring the opening of a valve provided on at least one of these elements, the valve being of the rotating ball type.
A valve of this type has a closure element of generally spherical shape, made as a horseshoe and comprising millings or piercings so as to position the closure element. This spherical closure element is mounted in a connecting element or male fitting or female fitting with its center coinciding with the axis of the channel for passage of the fluid to be controlled, this spherical closure element, which bears against a seat at the outlet of the channel in the valve chamber comprising a diametrical bore, which can by suitable means be brought into coincidence with the channel for the fluid to ensure opening of the valve or to be oriented substantially 90° to ensure closing of the valve.
A spherical closure element of this type comprises a rotation means such as two balls or a transverse shaft which is arranged to coact with a sleeve having the shape of a hollow shaft and which directs the fluid stream, the sleeve being prolonged at one end by a member such as an arm or a rod which is articulated on the rotation member. A fitting also comprises a cylindrical ring defining at its external end a bearing seat and the sealing in the cylindrical body and against which comes to bear the spherical closure member drivable in translation in the fitting according to the paths determining the conditions of opening and closing of the closure element, the assembly of these elements being enclosed in a concentric cylindrical body.
Such a connection is known from FR 2.521.685 in which the valve comprises a fixed axial sleeve disposed at the rear of the body of the fitting, directed toward the outlet of the connection and traversed by the passage of the connection, this sleeve comprising at its inner end corresponding to the rear of the body, a support for a return spring and at its external end, on the side of the connection region, a radial flange whose two lateral surfaces are tangent to the external surface of the sleeve, a chamber opening into the sector in the spherical region opposite to the active sector being provided in the spherical closure element, this chamber comprising surfaces cooperating in sliding contact with the side surfaces of the flange of the sleeve and the axle for driving in rotation the closure element being carried by the flange of the sleeve and perpendicular to said surfaces.
This type of pipe connection is used in hydraulic fields, in armament and in the field of space. In particular, it is used as a pipe connection for the fueling of vehicles. In the case of racing vehicles or military vehicles, it is desirable that the refueling take place as rapidly as possible and in a sure manner thereby guaranteeing perfect security of the connection.
Thus, in the case of use in automotive competition for example, the emplacement of the connection for refueling with gasoline must be carried out as rapidly as possible and with all security so as to avoid spilling gasoline on the brakes of the vehicle which would cause the vehicle to catch fire.
Present connections must be positioned correctly which is to say that the male fitting, or fueling fitting, must be presented to the female fitting, generally carried on the vehicle in the gas tank of the latter, perfectly along the axis to permit sure emplacement. This is not always easy to carry out on the one hand because of the weight of the material used, in particular when gravity fuelling is used, and on the other hand because of the conditions of use which can be difficult, as the fueling of a racing vehicle, mid-air fueling of an aircraft, etc.
SUMMARY OF THE INVENTION
The present invention has for its object to overcome this drawback by providing a new type of female fitting and a pipe connection of the type comprising a male fitting engaged in said female fitting, the engagement ensuring the opening of a valve provided on at least one of these fittings being permitted even if the constituent elements of one and the other are not perfectly aligned.
To this end, the invention has as its object a female fitting for a pipe connection adapted to be carried on a receiving structure such as a pipe or a reservoir, of the type comprising a cylindrical body within which is disposed concentrically a sleeve defining the fluid channel and carrying at its external end, articulated in rotation, a spherical closure element having a diametral bore, a cylindrical ring surrounding said sleeve and the spherical closure element being disposed drivably in translation in the cylindrical body against the force of resilient return means, the translatory paths of the ring in the body giving rise to driving in rotation of the spherical closure element between its opening position in which its bore coincides with the fluid channel and its closed position, characterized in that the sleeve and the cylindrical ring of this female fitting are mounted oscillably in the body of said fitting.
Thus, preferably, when the engagement of a male fitting is carried out with this female fitting, the freedom of oscillation of the sleeve and of the cylindrical ring in the body of the female fitting permit the assembly of the elements to assume the same axis to guarantee correct and sure connection, even if this engagement has a defect of alignment.
The internal end of the sleeve of the female fitting, which is to say the end of the sleeve turned toward the pipe or more precisely toward the gas tank in the case of an onboard fitting, has spherical bearing surface that bears against a complementary bearing surface of the internal end of the cylindrical body of the fitting in the manner of a swivel joint whilst the outer end of the cylindrical ring has a peripheral spherical bearing surface that bears against a bearing surface of complementary shape on the external end of the cylindrical body.
In this way, the spherical bearing surfaces of the sleeve and of the external end of the ring permit, by sliding against the complementary bearing surfaces of the cylindrical body, an oscillation of said sleeve and of the ring relative to the principal axis of the female fitting, to permit alignment of these members with those of a male fitting which does not lie on the same axis.
So as to promote sliding of the sleeve relative to the cylindrical body during oscillation, the internal end of the body and the internal end of the sleeve are treated to improve the sliding between said ends, with a treatment such as that known commercial as “Microflon”.
Preferably, at least one of the bearing surfaces of the internal end of the cylindrical body or of the internal end of the sleeve, comprises at least one ball bearing surface. The sliding of said bearing surfaces is thus improved.
As a modification, the bearing surface of the internal end of the cylindrical body comprises wells spaced regularly angularly about said spherical bearing surface and containing each a ball, a well having a central curved surface and a peripheral conical surface. There is thus ensured an automatic re-centering during oscillation.
The cylindrical ring of each fitting defines at its external end, on the side of the connection region, a sealing and bearing seat for the spherical closure element, also called a joint capture cross-piece which serves for the creation of a trapezoidal throat to receive a joint. This sealing and bearing seat provides in the female fitting the peripheral spherical bearing surface.
The resilient return means permitting sliding in translation of the cylindrical ring within the cylindrical body of the female fitting is preferably a spring mounted between the cylindrical ring and the sleeve. Preferably, this resilient return means is disposed between the external end of the cylindrical ring which it maintains in sealed bearing relationship with the cylindrical body and the internal end of the sleeve which it maintains in bearing relation on the cylindrical body. The ring and the sleeve are thus connected and can oscillate together within the cylindrical body.
The sleeve of the female fitting is preferably short, which permits a saving in size and weight of the female fitting. This is particularly advantageous when the female fitting is onboard a race car for example.
According to a preferred embodiment of the invention, the spherical closure element of the fitting is made to horseshoe shape and comprises moreover two diametrically opposed flats provided respectively on an axis and on a cylindrical casing having sectors made in fork shape is disposed concentrically to the interior of the cylindrical ring, the axles of the spherical closure element being disposed in said forks, the fingers of the forks entering into recesses provided in the thickness of the seat for sealing and bearing under the influence of a resilient return means such as a Belleville washer or the like disposed between said cylindrical casing and the internal end of the cylindrical ring.
In this embodiment, the center of the spherical element is strictly invariable no matter what axis is considered, its centering within the fluid stream separates it from any risk of parasitic friction. Thus the strength of the assembly during oscillation is promoted.
So as further to promote the engagement of a male fitting and a female fitting which can be rendered difficult because of the weight and the rigidity of the tubing to which the male fitting is connected, there can be emplaced between the receiving structure of the female fitting and the cylindrical body of said female fitting, a bellows which permits mating with the extreme angular positions.
The present invention also has for its object a pipe connection of the type comprising a female fitting according to the invention and a male fitting comprising a cylindrical body within which is disposed concentrically a sleeve defining the fluid channel and carrying at its outer end, articulated in rotation, a spherical closure element having a diametrical bore, a cylindrical ring, surrounding said sleeve and the spherical closure element, being disposed drivably in translation in the cylindrical body against the force of a resilient return means, the translatory paths of the ring within the body giving rise, during engagement of the male fitting on the female fitting, to the driving in rotation of the spherical closure element between its open position in which its bore is brought into coincidence with the fluid channel, and its closed position, characterized in that the sleeve of the male fitting provided at its external end with the spherical closure element and surrounded by the cylindrical ring, is mounted projecting from the cylindrical body and the male fitting moreover comprises a casing engaged between the cylindrical ring and the cylindrical body, sliding in translation in said cylindrical body, a resilient return means being interposed between the cylindrical body and the front surface of said casing which ensures the engagement against the female fitting.
Thus, the ring and the casing constitute a portion in the form of a piston for engagement on the female fitting.
Preferably, the spherical closure member of the male fitting is made as a horseshoe and comprises moreover two diametrically opposed flats provided respectively with an axle.
In the male fitting, the sleeve has at its end a cylindrical casing having sectors made in horseshoe shape in which are disposed the axles of said spherical closure element so as strictly to control the centering of said spherical closure element, a resilient return means being interposed between the cylindrical casing and the sleeve.
During engagement of the male fitting on the female fitting, sealing is ensured by the emplacement of the casing on the facade of the female fitting. Preferably, the front engagement surface of the casing is made in the form of a trumpet-shaped cone which promotes a blind engagement for bringing together the fronts of the male and female fittings constituting the interface between the fittings.
According to a preferred embodiment, the connection according to the invention comprises a second circulation circuit substantially concentric with the fluid channel, for example for collecting gas.
Thus, the cylindrical ring of the male fitting has at least two peripheral lobes which define passages between said ring and the casing, said passages communicating with an evacuation conduit opening into the cylindrical body of the male fitting whilst the cylindrical body of the female fitting comprises openings which, during connection between the male fitting and the female fitting, are placed in communication with the passages of the male fitting.
During emplacement of the connection according to the invention, a circuit separate from the fluid channel is thus established between a gas tank or conduit in which is mounted the female fitting and an evacuation conduit opening into the male fitting and in which is established a circulation through openings of the cylindrical body of the female fitting and passages defined by the lobes of the cylindrical ring of the male fitting, toward the pipe.
Thus, a connection according to this embodiment of the invention forms, during engagement of the male fitting on the female fitting, a closed passage which can serve for collecting gas and can be preferably used in the case of fueling with evaporable fluids such as compressed gas of which liquefied natural gas (cryogenic), combustibles and generally speaking all liquids which, stored, have both a liquid phase and a vapor phase.
When the interface has been established by engagement of the front engagement surface of the casing of the male fitting on the front surface of the female fitting, the bearing seat and the seal of the male fitting come to bear against the bearing seat and seal of the female fitting and press the latter back into the cylindrical body of the female fitting. The seal within the female fitting is broken and a passage is opened for the gas from the gas tank or pipe through openings of the female fitting. The release of gas from the gas tank thus commences, the gas is then passing into the passages defined by the lobes of the cylindrical ring of the male fitting, toward the conduit opening into the male fitting, such that there can thus be a collection of the gases.
The return of the cylindrical ring of the female fitting also permits progressive opening of its spherical closure member. Once the gas tank is fully open, the ring bears against the rear end of the female fitting, and abuts under the influence of the pressure of the operator, arising during return of the cylindrical ring of the male fitting in the cylindrical body of said male fitting which gives rise to the opening of the spherical closure element of the male fitting.
To avoid small quantities of combustible interfering with the gas flow, torque joints (static sealing) are disposed on the one hand on the conical shoulder of the interface and on the other hand in the rear base of the onboard connection.
Preferably, the casing of the male fitting has openings permitting visualizing, preferably over 360°, of the filling by the operator, by noting the rise of bubbles preceding the filling of the gas tank, and the possible resulting overflow from overfilling.
This device, constructed such that the casings and rings have staged diameters, permits the production of a mechanical assembly in which the risks of wedging are avoided.
Preferably, the translatory paths of the ring and the casing of the male fitting, of the ring of the female fitting relative to their respective cylindrical bodies and the force of the resilient return means determine the kinematics of opening and closing the spherical closure elements as well as that of the second circuit for gathering gas for example.
Thus, as to the transfer of evaporable fluids, whether it is a matter of respecting the environment, or of the safety of people and materials, or whether it is a matter of quick operation or avoiding for military apparatus (armored, helicopters) the radar signature of refueling at night or in fog, the connection according to the invention permits collecting the gas without requiring an implantation of a loop having to be provided for the connection, as was previously the case.
For these applications, the connection according to the invention permits any maneuver of transfer involving collection of gases, this degassing taking place even when filling has not begun and ending only after filling has been completed.
In the case of automotive competition, the connection according to the invention permits gravity refuelling whilst ensuring filling carried out in record time and suitable degassing, whilst protecting the operators, the vehicles as well as the pilots, which permits better controlling the numerous requirements for successive refueling during endurance races of the 24-hour type at Mans, for example.
The connection according to the invention thus has a direct passage velocity, a drastic reduction of weight and size of the onboard portion (female fitting), an operation according to the principle of gravity, the ability to be used under other circumstances under pressure by requiring only slight modifications, a rigorous automation (the connection follows an invariable sequence), maximum performance, and which ensures simultaneously the functions: of transferring combustible in laminar flow, according to φ33 m/m, (855 m/m 2 ) for example, degassing of the gas tank under static conditions by a quasi-rectilinear passage which offers a passage cross-section of about 1700 m/m 2 , for example, the recovery of the gas is in static condition requiring a cross-section 1.5 times that of the supply.
Responding to the dead man principle and to the concept of gravity, the connection according to the invention satisfies all the requirements, whether in terms of effectiveness, reliability, safety or ergonomics.
According to a pre-established automatic and invariable sequence, the connection according to the invention guarantees centering and blind engagement, by peripheral guiding of the trumpet cone provided on the male fitting, a seating (and unseating) without risk of wedging, mechanical alignment of the components because of the oscillation of the sleeve and of the cylindrical ring within the female fitting, the automatic opening of the degassing openings then, consecutively, the opening of the closure of the gas tank, finally, the opening of the closure of the refueling male fitting, and conversely, the refilling having been accomplished and according to said sequence, the readability about 360°, of a possible reflux resulting from an overfill, and by disengagement, the closing of the closure of the refilling fitting (supply), the residual flow of the interface into the reservoir (automobile), the closing of the closure of the female fitting of the gas tank and then the end of degassing, finally the separation of the two fittings, even as a result of an abrupt startup.
It is to be noted that after overfilling, the connection according to the invention permits manual purge of the degassing circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
There will now be described in greater detail a connection according to an embodiment of the invention with reference to the drawings, in which:
FIGS. 1 a and 1 b show respectively a view in longitudinal cross-section of a female fitting of a connection according to the invention, in the closed and in the open position,
FIG. 2 is a longitudinal cross-sectional view of a female fitting according to FIG. 1 a after rotation by 90°;
FIGS. 3 a and 3 b represent respectively a view in longitudinal cross-section of a male fitting of a connection according to the invention, in the closed and in the open position;
FIG. 4 is a longitudinal cross-sectional view of the connection according to the invention, in the front connection position of the two fittings;
FIG. 5 is a view like FIG. 4 in the partially open position of the connection;
FIGS. 6 a and 6 b show respectively a view in side perspective and a view in longitudinal cross-section of the sleeve and of the spherical closure element of the male fitting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A pipe connection according to the invention comprises a female fitting 1 and a male fitting 8 .
The female fitting 1 comprises a cylindrical body 10 or mounting on the gas tank of a vehicle for example.
In this cylindrical body 10 is mounted a sleeve 2 defining the fluid channel C at the external end of which is mounted a spherical closure element 3 , a ring 4 being engaged slidably in the cylindrical body 10 and surrounding the sleeve 2 and the closure element 3 .
The inner end of the sleeve 2 , on the side of the gas tank of a vehicle, opposite its external end in connection with the closure element 3 , has a bearing surface 10 a provided at the inner end of the cylindrical body 10 opposite to its connection face 10 b.
The end of the ring 4 a on the external side of the female fitting 1 defines a sealing and bearing seat 5 against which bears the spherical closure element 3 and is provided with a peripheral bearing surface 6 of spherical shape in sealed bearing against a complementary bearing surface 10 c of the cylindrical body 10 , a resilient return means such as a spring 7 being interposed between the bearing surface 2 a of the sleeve 2 and the peripheral bearing surface 6 of the ring 4 .
Under the influence of the resilient return means 7 , the peripheral bearing surface 6 of the ring 4 is maintained in sealed bearing against the complementary peripheral bearing surface 10 c of the cylindrical body 10 , the closure element 3 being in the closed position.
Preferably, the spherical closure element 3 is held spaced from the bearing and sealing seat 5 by a joint, the seat 5 serving as a cross-member for holding the joint defining a trapezoidal throat G for the joint. There is thus avoided the risk of abrasion and/or clogging of the sphere of the spherical closure element 3 when, for example, the latter is used for high vapor pressure fluids such as combustibles which have a low wetting power. There is thus avoided the risk of incomplete closure or of blockage.
Preferably, the joint is clad with a soft material such as that known by the commercial name “Teflon”. This joint can be an O ring of large cross-section and high “Shore” hardness, of the FEP type, or a U shape joint of Teflon held in shape by a spring of the “Variseal” type, or else a large cross-section O ring capped with a journal bearing of the “double delta or plus seal” type.
As can be seen in FIG. 2 in the upper portion of the figure, at least one of the bearing surfaces 10 a of the inner end of the cylindrical body 10 or 2 a of the inner end of the sleeve 2 , comprises at least one ball bearing surface B. There is thus promoted the sliding of said bearing surfaces 10 a and 2 a against each other.
As a modification, as is shown in the lower portion of FIG. 2, the bearing surface 10 a of the inner end of the cylindrical body 10 comprises wells D distributed angularly regularly over said bearing surface 10 a of spherical shape and each comprising a ball C, a well D having a central spherical surface and a peripheral conical surface. Thus, for example, there are emplaced five balls C of large diameter in five wells D spaced apart by 72°, these balls C being called upon to move over a cylindrical surface of the well D in the central region and conical peripheral region. The cone has a ramp angle, for example 10° of slope, relative to the tangent plane A. There is thus assured an automatic recentering during oscillation.
When it is desired to open the female fitting 1 , there is exerted pressure on the bearing and sealing seat 5 against the force of the resilient return means 7 . This pressure presses the ring back into the cylindrical body 1 and the closure element 3 is then driven by the ring 4 in rotation at the end of the sleeve 2 until its open position (FIG. 1 b ), the articulation of the spherical closure element 3 on the sleeve 2 is the same for the male fitting 8 and will be explained later with reference to FIGS. 6 a and 6 b.
The spherical bearing surfaces 2 a and 6 provided at the inner end of the sleeve 2 and at the outer end of the ring 4 bearing against each other on supplemental bearing surfaces 10 a and 10 c of the cylindrical body 10 , permit an oscillation of the ring assembly 4 , sleeve 2 and the closure element 3 in the cylindrical body 10 by sliding against each other such that, when a male fitting 8 is connected, this oscillation permits the emplacement of the connection even when the male fitting 8 is engaged on the female fitting 1 misaligned, because it permits an alignment of the components of the male fitting 8 and the female fitting 1 , the sleeve 2 and the cylindrical ring 4 pivoting to reach alignment with the male fitting 8 .
The spherical closure element 3 is made as a horseshoe and comprises moreover two diametrically opposed flats 13 and provided respectively with an axle 14 . A cylindrical casing 30 having sectors made in the form of forks 31 in which are disposed the axles 14 of said spherical closure element 3 , is disposed concentrically within the cylindrical ring 4 . The fingers of the forks 31 fit into recesses 33 provided in the thickness of the sealing and bearing seat 5 under the force of a resilient return means such as a Belleville washer 32 or the like, emplaced between said cylindrical casing 30 and the inner end of the cylindrical ring 4 .
The centering of said spherical closure element 3 is strictly controlled and there is ensured a perfect holding of the assembly of the sleeve 2 , ring 4 and spherical closure element 3 during oscillation.
The mail fitting 8 comprises a cylindrical body 8 in which is fixedly mounted a sleeve 9 defining a fluid channel C′ closed by a spherical closure member 3 ′, similar to that of the female fitting 1 , mounted at the outer end of the sleeve 9 .
This sleeve 9 comprises at its outer end a radial flange 11 (see FIG. 6 b ) whose two side surfaces are tangent to the external surface of the sleeve 9 , a chamber opening into the sector of spherical zone opposite the active sector, being provided in the spherical closure element 3 ′, this chamber comprising surfaces in sliding contact with the side surfaces of the flange 11 of the sleeve 9 and the rotary drive axle 12 of the closure element 3 ′ being carried by the flange 11 of the sleeve 9 and perpendicular to said surfaces. The sleeve 2 has a similar structure.
The spherical closure element 3 ′ of the male fitting is also made as a horseshoe and comprises moreover two diametrically opposed flats 13 and provided respectively with an axle 14 . The sleeve 9 has at its end a cylindrical casing having sectors made as forks 15 in which are disposed the axles 14 of said spherical closure element 3 ′ so as strictly to control the centering of said spherical closure element 31 , a resilient return means 40 being disposed between the sleeve 9 and the cylindrical casing.
The sphere of the spherical closure element 3 ′ of the male fitting 8 has a recess 3 ′ a to permit the rotation of the sphere of the closure element 3 of the female fitting 1 .
A cylindrical ring 16 extends about the sleeve 9 and the closure element 3 ′ and defines at its outer end the sealing and bearing seat 17 against which the spherical closure element 3 ′ bears.
This ring 16 is slidably mounted for translation within the cylindrical body 80 against the effect of a resilient return means such as a spring 81 interposed between the base of the cylindrical body 80 at its inner end, on the side of the refueling pipe for example, and the inner end of said ring 16 , the path of said ring 16 within the cylindrical body 80 permitting the opening and closing of the spherical closure element 3 ′.
This path is defined by at least one opening 18 provided radially in the ring 16 and in which is engaged a pin 19 fixed in the cylindrical body 80 .
A cylindrical casing 20 is interposed between the ring 16 and the cylindrical body 80 . This casing 20 has at its outer end a front portion for engagement on the facade 10 b of the female fitting 1 provided in the form of a trumpet cone 21 . The casing 20 projects relative to the sealing and bearing seat 17 . This casing 20 has at least one radial opening 22 in which is also engaged the pin 19 of the cylindrical body 80 , the opening 22 delimiting a sliding path of this casing 20 within the cylindrical body 80 against the resilient return force of a spring 23 emplaced between the outer end of the cylindrical body 80 and the outer end of the casing 20 .
To promote concentricity of the male fitting, three pins are provided.
Preferably, the ring 16 comprises a lobed periphery defining between each lobe 24 a passage 25 between said ring 16 and a casing 20 , the passage 25 being in communication at the rear of the cylindrical body 80 with a pipe 26 opening into said cylindrical body 80 .
The casing 20 comprises openings 27 permitting the readability of filling by the opertor.
Preferably, the male fitting 8 comprises wide and strong handles 28 to permit its gripping and manipulation. Moreover, said handles 28 protect the facade of the male fitting 8 , also called the refueling or coupling fitting, from deterioration or pollution in the case of being dropped.
When the male fitting 8 is engaged on the female fitting 1 , a misalignment of the assembly is corrected by the oscillation of the sleeve 2 and the ring 4 in the female fitting 1 , the spherical bearing surfaces 2 a and 6 sliding against the complementary bearing surfaces 10 a and 10 c of the cylindrical body 10 .
When the interface has been established, the bearing and sealing seat 17 of the male fitting 8 comes to bear against the bearing and sealing seat 5 of the female fitting 1 and the ring 16 pushes the ring 4 back within the cylindrical body 10 of the female fitting 1 . The seal within the interior of the female fitting 1 is broken and a passage is opened for gas through openings 10 d provided in the wall of the cylindrical body 10 of the female fitting 1 . Degassing of the gas tank thus begins, the gases passing through said openings 10 d and then into the passages 25 defined by the lobes 24 of the cylindrical ring 16 of the male fitting 8 , toward the conduit 26 opening into the male fitting 8 , such that there can there be a collection of the gases (arrows in FIG. 5 ).
The return of the cylindrical ring 4 of the female fitting 1 also permits progressively opening its spherical closure element 3 (FIG. 5 ). Once the gas tank is fully open, the casing 20 of the male fitting 8 has completed its translatory movement whilst the cylindrical ring 16 of the male fitting 8 undergoes its return into the cylindrical body 80 , under the pressure of the operator, and will give rise to opening of the spherical closure element 3 ′ of the male fitting 8 .
The translatory paths of the ring 16 and of the casing 20 of the male fitting 8 , of the ring 4 of the female fitting 1 relative to their respective cylindrical bodies 80 and 10 , and the force of the resilient return means 7 , 23 and 81 determine the kinematics of opening and closing of the spherical closure elements 3 and 3 ′, as well as of the second circuit for collecting gases for example. | A faucet for pipe connection designed to be incorporated in a receiving structure such as a pipe or tank, includes a cylindrical body inside which is housed in concentric manner a sleeve defining the fluid communication channel and bearing at its outer end, articulated in rotation, a spherical closure element having a diametrical bore, a cylindrical ring, enclosing the sleeve and the spherical closure element, being housed so as to be capable of being driven in translation in the cylindrical body countering the effect of elastic return elements, the strokes in translation of the ring in the body driving in rotation the spherical closure element between an opening position wherein its bore is brought to coincide with the fluid communication channel and its closing position. The sleeve and the cylindrical ring of the faucet are mounted oscillating in the body of the faucet. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 998,501, filed Dec. 30, 1992, which is a division of application Ser. No. 267,056, filed Nov. 4, 1988, now U.S. Pat. No. 5,177,276, which is a continuation of application Ser. No. 017,496, filed Feb. 24, 1987, now abandoned, which is a continuation-in-part of application Ser. No. 005,994, filed Jan. 21, 1987, now abandoned, which is a continuation of application Ser. No. 744,998, filed Jun. 17, 1985, now abandoned.
FIELD OF THE INVENTION
The present invention relates to viscosity index improvers for lubricating oils and to lubricating oil compositions containing such viscosity index improvers. More particularly, the present invention relates to liquid, alpha-olefin oligomeric shear stable viscosity index improvers for lubricating oils and to lubricating oils having an improved viscosity index containing alpha-olefin oligomeric shear stable viscosity improvers. The shear stable alpha-olefin oligomers of the invention are also useful as viscosity enhancing base oils, either neat or in blends where high viscosity industrial lubricants are desired.
BACKGROUND OF THE INVENTION
Petroleum oils have been conventionally used as lubricating oils in internal combustion engines. In the past, a thinner, lighter weight oil had to be used in colder climates in order to provide sufficient fluidity for initial lubrication at low temperatures. However, as the engine continued to operate and heat up the oil, the oil became thinner and at higher operating temperatures had insufficient viscosity for optimum lubrication. In warm weather operation a heavier weight oil was required, because the thinner, lighter weight oil provided insufficient lubrication at such higher temperatures. The viscosity-temperature relationship of an oil is expressed as its "viscosity index".
In order to improve the viscosity index of lubricating oils, it has been proposed to incorporate various polymeric materials into the base stock in order to improve the inherent viscosity-temperature characteristics of the lubricating oil. One common class of commercial polymeric viscosity index improvers are the methacrylate polymers, such as polymethacrylate esters. High molecular weight viscosity modifiers formed from alpha-olefin polymers have been proposed, such as those having a weight average molecular weight in excess of 50,000, as described in U.S. Pat. No. 3,795,616 to Heilman et al.
Lower molecular weight alpha-olefin oligomers and copolymers have been proposed for use as base fluids, such as those produced, and thereafter hydrogenated, using boron trifluoride and a co-catalyst, such as n-butanol described in U.S. Pat. No. 4,032,591 to Cupples et al. However, such hydrogenated oligomers have had little or no effect when attempts have been made to utilize small amounts of such materials as viscosity index improvers for lubricating oils.
The aforementioned U.S. Pat. No. 3,795,616 to Heilman et al describes polymers of alpha-olefins having from 5 to 12 carbon atoms which are useful as viscosity enhancers for lubricating oils. The alpha-olefin polymers of Heilman et al are high molecular weight materials having a weight average molecular weight between 50,000 and 1,000,000 and a ratio of weight average to number average molecular weight of from 1 to 12. Heilman et al also teach that any Ziegler-Natta type catalyst can be employed to prepare these polymers.
U.S. Pat. No. 3,346,498 to DeVries describes high molecular weight copolymers of alpha-olefins and diolefins having 11 to 15 carbon atoms which lower the pour point of waxy mineral lubricating oils. These polymers are taught as having a molecular weight of 50,000 to 1,000,000 and are prepared using a catalyst containing a titanium halide and an organo aluminum compound.
Canadian Patent No. 734,980 to Sauer et al discloses lower molecular weight polymers of alpha-olefins having 6 to 16 carbon atoms which are useful as synthetic lubricating oils having a high viscosity index. The polymers of Sauer et al are described as having an average molecular weight ranging from about 300 to 2,000. These polymers are prepared using a catalyst of titanium tetrachloride and an organo aluminum compound, wherein the molar ratio of titanium to aluminum is from 2:1 to 20:1. Sauer et al teach that this molar ratio is important to produce normally liquid polymers. If the molar ratio of titanium to aluminum is below 2:1, Sauer et al teach that undesirable solid polymers are produced.
U.S. Pat. No. 3,403,197 to Seelbach et al discloses low molecular weight unsaturated polymers of alpha-olefins having from 3 to 40 carbon atoms. The polymers of Seelbach et al are described as having a cryoscopic molecular weight of from 150 to 1,500 and are prepared using a catalyst consisting of violet titanium trichloride and a monoalkyl aluminum dihalide.
SUMMARY OF THE INVENTION
A liquid alpha-olefin oligomer has been fond which provides exceptional viscosity index improvement when admixed with a lubricating oil base stock comprising either a petroleum or synthetic base oil.
Moreover, the alpha-olefin oligomer itself has been found to be very effective as a viscosity enhancing base oil, which also exhibits unexpectedly good shear stability. Accordingly, the present invention provides a normally liquid alpha-olefin oligomer consisting essentially of repeating units having the structural formula: ##STR2## wherein x represents an integer from 3 to 11, inclusive; and
y represents the number of repeating units in the oligomer such that the weight average molecular weight is from about 5,000 to about 20,000;
said oligomer having from about 70 to 100 percent head-to-tail alignment of the repeating units of the oligomer. Preferably the weight average molecular weight of the oligomer is from 5,000 to about 10,000; and said oligomer is further characterized as having a dispersity of less than about 5.5, and a Z average molecular weight of less than about 24,000.
By the expression "70 to 100 percent head-to-tail alignment" is meant that from 70 to 100 percent of each oligomer molecule is a block of monomer units connected head-to-tail or by 1-2 addition. For example, in the oligomerization of 1-decene, if the first (head) carbon atom in every 1-decene monomer molecule joins with another 1-decene monomer molecule by binding to its second (tail) carbon atom, this would be 100 percent head-to-tail alignment.
According to another aspect of the present invention, a lubricating oil composition is provided comprising a lubricating oil base stock, such as a petroleum or synthetic oil, and an alpha-olefin oligomer of the present invention.
According to a further aspect of the present invention, a one-step process is provided for producing the normally liquid alpha-olefin oligomers of the invention, which process comprises contacting, as the sole polymerizable compound, an alpha-olefin having from 6 to 14 carbon atoms with a catalyst comprising the purple form of titanium trichloride and an alkyl aluminum compound selected from the group consisting of trialkyl aluminum, dialkyl aluminum hydride, alkyl aluminum dihydride, dialkyl aluminum halide and alkyl aluminum sesquihalide, in the presence of free molecular hydrogen. The alpha-olefin oligomers produced by the present process will generally have a bromine index of from about zero to about 2,000.
Moreover, when carrying out the process of the invention, a mixture of alpha-olefins having from 6 to 14 carbon atoms per molecule may be employed to produce oligomers having repeating units derived from two or more different alpha-olefin monomers. Accordingly, the present invention also provides a normally liquid alpha-olefin oligomer consisting essentially of repeating units having the structural formula: ##STR3## wherein x represents an integer from 3 to 11, inclusive, and x can be variable from one repeating unit to another;
y represents the number of repeating units in the oligomer such that the weight average molecular weight is from about 5,000 to about 20,000;
said oligomer having from about 70 to 100 percent head-to-tail alignment of the repeating units of the oligomer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The alpha-olefin oligomers of the present invention are produced by oligomerizing an alpha-olefin monomer having from 6 to about 14 carbon atoms per molecule, or mixtures thereof. The term "oligomerization" is employed herein to describe the conversion of the C 6 to C 14 alpha-olefin monomers to a higher molecular weight normally liquid product having a weight average molecular weight in the range of from about 5,000 to about 20,000, preferably from about 5,000 to about 10,000.
As indicated, suitable monoolefins include alpha-olefin monomers having from about 6 to about 14 carbon atoms, such as 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene and 1-tetradecene, preferably from 1-octene to 1-dodecene, and more preferably from 1-octene to 1-decene. An especially preferred alpha-olefin is 1-decene. Mixtures of these alpha-olefins can also, of course, be employed.
The alpha-olefin monomer is contacted with a catalyst containing the purple form of titanium trichloride and an alkyl aluminum compound selected from the group consisting of trialkyl aluminum, dialkyl aluminum hydride, alkyl aluminum dihydride, dialkyl aluminum halide and alkyl aluminum sesquihalide. In general, the alkyl group can have from about 1 to 8 carbon atoms, preferably from about 2 to 4 carbon atoms.
Suitable alkyl aluminum compounds include, for example, trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tri-normal octyl aluminum, diisobutylaluminum hydride, isobutyl aluminum dihydride, diethylaluminum chloride, diisobutylaluminum chloride and ethylaluminum sesquichloride. Preferred alkyl aluminum compounds are the dialkyl aluminum hydrides, such as diisobutylaluminum hydride, and the alkyl aluminum sesquichlorides, such as ethylaluminum sesquichloride. An especially preferred alkyl aluminum compound is diisobutylaluminum hydride.
The purple form of titanium trichloride can either be used preformed, or generated in situ by reduction of TiCl 4 . The purple TiCl 3 should have a general crystal structure which is hexagonal, or cubic close packed, or a mixture of hexagonal and cubic close packed, with a bulk density of 40 to about 100 pounds per cubic foot, preferably from about 60 to about 90 pounds per cubic foot. Such crystals should have an average particle size distribution of from about 5 microns to about 200 microns, preferably from about 10 to about 100 microns. In general, higher surface areas promote higher activities. Thus, especially preferred surface areas are from about 10 to about 100 square meters per gram, preferable from about 30 to about 70 square meters per gram.
Suitable oligomerization temperatures include, for example, temperatures of from about 0° to about 200° C., preferably from about 25° to about 150° C., with from about 60° to about 120° C. being more preferred.
The oligomerization reaction is conducted in the presence of a suitable molecular weight regulator, such as hydrogen or diethylzinc. Hydrogen is the preferred molecular weight regulator.
Another unexpected benefit for the process of this invention where hydrogen is used, is the production in one step of an alpha-olefin oligomer product having an unexpectedly low bromine index, indicating the oligomer is being saturated during the processing. This oligomer saturation is unexpected due to the use of relatively low total pressures and low hydrogen partial pressures. The prior art, for example, Canadian Patent No. 734,980 to Sauer et al, and U.S. Pat. No. 3,795,616 to Heilman et al, teach the use of hydrogen in the oligomerization step solely as a molecular weight control agent. Sauer et al teach the subsequent hydrogenation of their very low molecular weight oligomers to produce a desired saturated product. It is a distinct benefit to the process of this invention to produce substantially saturated oligomers as a product of the oligomerization step without the need for a second stage or subsequent hydrogenation step.
The oligomerization pressure is suitable from about 1 to about 175 atmospheres, preferably from about 5 to about 25 atmospheres total pressure. If hydrogen is used as the molecular weight regulator, suitable hydrogen partial pressures can be from about 1 to about 158 psig (1 to about 11.75 atmospheres), preferably from about 60 to about 120 psig (4.08 to about 8.13 atmospheres).
As noted above, an added advantage of the process of this invention is that a substantially fully-saturated product can be obtained which does not require post hydrogenation. The obtention of this substantially fully-saturated product is a function of the particular catalyst employed, the catalyst concentration, and other reaction conditions. For example, when the catalyst employed is diisobutyl aluminum hydride, the use of a relatively low partial pressure of hydrogen of 100 psig resulted not only in the use of hydrogen as a molecular weight control agent, but also in the production of a substantially fully-saturated product, that is, one having a bromine index of less than about 500. Higher hydrogen partial pressures within the range noted above may be required with other catalysts to produce a substantially saturated oligomer product in one step.
Additionally, it has been found that there is some saturation of the alpha-olefin feed during the oligomerization process conducted in the presence of hydrogen. The unconverted feed, which usually contains from about 50 to 100, more usually 80 to 100, weight percent saturated alpha-olefin, can be, if desired, recycled to the oligomerization process to serve as the reaction solvent.
The oligomerization reaction can be conducted in either batch, semi-continuous, or continuous reaction.
If desired, a diluent may be employed for the oligomerization reaction. Suitable diluents include hydrocarbon solvents, such as pentane, hexane, heptane, and the like, naphtha, gasoline fractions, kerosene, gas oil fractions, furnace oil fractions, light lubricating oils, heavy lubricating oils, and the like. In one preferred embodiment, the diluent is the saturated form of the alpha-olefin charge stock which, as noted above, can be formed in situ and recycled to the process. Organic hydrocarbon solvents, such as benzene, toluene, the xylenes, and the like, and chlorinated hydrocarbon solvents are less preferred. A solvent is not required, since the oligomeric product is a pourable liquid. However, if desired, the aforesaid diluent can be used in amounts of from about 10 to about 90 weight percent, preferably from about 30 to about 70 weight percent.
The amount of purple titanium trichloride employed in the catalyst is generally from about 0.1 to about 1.5 weight percent of the alpha-olefin feed. The molar ratio of titanium to aluminum in the catalyst will generally range from about 0.2:1 to 4:1, preferably from about 0.3:1 to 1.3:1, and more preferably will be about 1:1.
Suitable oligomerization reaction times include from about 5 minutes to about 20 hours, preferably from about 10 minutes to about 5 hours, with from about 30 minutes to about 3 hours being especially preferred.
In addition to the fact that the oligomers of the invention are saturated during the oligomerization process, thus eliminating the need for an expensive secondary hydrogenation process, the high viscosity oligomers of this invention can be recovered by simple distillation at normal pressures as a total bottoms product. The overhead from the distillation recovers the reaction solvent and, at times, the unconverted feed and the total oligomer product can be directly recovered as a bottoms product. For the higher carbon number olefin feeds, for example, 1-decene, a vacuum distillation is preferred to recover the unconverted feed. The raw oligomer product is preferably washed with dilute hydrochloric acid to remove catalyst residues and then water washed until neutral, prior to recovery by distillation.
Oligomerization catalysts and conditions are selected to provide an oligomeric product having a weight average molecular weight of from about 5,000 to about 20,000, preferably from about 5,000 to about 10,000, and more preferably from about 6,500 to about 8,000. Moreover, the resulting structure of the oligomeric product of the present invention contains from about 70 to about 100 percent head-to-tail alignment of the repeating units in the oligomer, preferably from about 90 to about 100 percent head-to-tail alignment.
The dispersity, or distribution factor, is defined as the ratio of weight average molecular weight to number average molecular weight, that is, Mw/Mn. For the alpha-olefin oligomers of the present invention, the dispersity should generally be less than 5.5, and preferably will be between about 2.5 and 4.5. In order to achieve the desired dispersity, the number average molecular weight for the oligomers of the invention will generally range from about 1,000 to about 4,000, preferably from about 1,000 to about 2,500.
In addition, the Z average molecular weight for the alpha-olefin oligomers of the present invention will normally be less than about 24,000, and usually from about 14,000 to 20,000.
The weight average molecular weight, number average molecular weight and Z average molecular weight for the alpha-olefin oligomers of the invention are determined by gel permeation chromatography. For decene-1 oligomers, the chromatography column was calibrated with polydecene-1 oligomers of known molecular weight. The methods of calculation and definitions of the above molecular weight terms are discussed, for example, in "The Elements of Polymer Science and Engineering--An Introductory Text for Engineers and Chemists", by Alfred Rudin, Chapter Two, Page 53, Academic Press, 1982.
The molecular weight distribution of the alpha-olefin oligomers of the invention, in terms of area percent using gel permeation chromatography, lies within a relatively narrow range. In general, the molecular weight distribution will be such that less than 40 percent, and preferably less than 29 percent, of the oligomer of the invention will have a molecular weight greater than 9,000. Moreover, less than 10 percent, and preferably less than 5 percent, of the oligomer of the invention will have a molecular weight greater than 29,000.
The alpha-olefin oligomers of the invention possess very high viscosities, which makes these oligomers highly suitable as viscosity enhancing base stocks, either neat or in blends where high viscosity industrial lubricants or greases are desired. In general, the oligomers of the invention, having the preferred weight average molecular weight of about 5,000 to about 10,000, will have viscosities in the range of about 150 to 1250 centistokes (cs.), preferably in the range of about 150 to 500 cs., and more preferably, about 250 to 400 cs., at 210° F., as determined by ASTM D445.
The alpha-olefin oligomers of the invention have also been found to exhibit excellent shear stability. In general, the oligomers of the invention will have a shear stability of less than 10 percent, preferably less than 6 percent, and more preferably less than 4 percent, as measured by the average percentage loss in kinematic viscosity at 100° F. and 210° F. of 3 weight percent blends of the alpha-olefin oligomer of the invention in lubricating oil base stocks of C 20 to C 50 carbon number after 30 minutes of sonic shearing at 100° F.
Another important property of the alpha-olefin oligomers of the invention is their low bromine index, which generally ranges from about zero to about 2,000, and preferably will be less than about 750.
The alpha-olefin oligomers of the present invention have additionally been found to possess excellent viscosity index improving characteristics.
Surprisingly, the oligomeric product of the present invention provides exceptional viscosity index improvement to both petroleum base oils and synthetic base oils, while using only minor amounts of the viscosity index improving oligomers of the present invention.
Thus, from about 0.5 to about 40, preferably from about one to about 15, weight percent of the viscosity index improving oligomer of the present invention provide excellent improvement in the viscosity index of petroleum base stocks, such as conventional mineral oil base stocks or base stock blends with or without conventional additives. Additionally, such amounts of the viscosity index improving oligomers of the present invention may be added to synthetic lubricating oils, such as those produced from polymerized alpha-olefins, Fisher-Tropsch produced oil, or the like. In general, the base stocks employed with the present oligomer will have a viscosity at 210° F. of from about 2 to about 100 cs. The amount of base stock present in these lubricating oil compositions will generally range from about 60 to 99.5 weight percent of the total composition. Mixtures of petroleum base oils and synthetic base oils may also be employed.
The viscosity index improving oligomers of the present invention provide not only significant improvement in viscosity index to such base stocks, but, in addition, have improved shear stability as compared with those resulting from the use of higher molecular weight viscosity index improvers.
Accordingly, the preferred lubricating oil compositions comprise a lubricating oil base stock and a minor viscosity index improving amount, that is, about 1.0 to 15 weight percent, of the oligomer of the invention, and said oligomer having a viscosity of about 150° to about 500 cs. at 210° F. will generally exhibit a shear stability of less than about 10%, as measured by the average percentage loss in kinematic viscosity at 100° F. and 210° F. after 30 minutes of sonic shearing at 100° F.
The lubricating oil compositions provided by the viscosity index improving oligomers of the present invention provide a product having a viscosity of from about 2.5 to about 150 cs. at 210° F., as determined by ASTM D445.
The following examples are presented to illustrate the invention. All percentages are by weight except where otherwise indicated. The viscosity measurements that are used herein are the kinematic viscosities in centistokes (cs.) as determined by ASTM D445. The viscosity indexes were determined by ASTM D2270 and the various oligomer analyses were determined by gel permeation chromatography.
EXAMPLES
Examples 1-8
The monomer, 1-octene, was introduced into a one-liter autoclave (Hastalloy B) which had been previously purged with dry nitrogen. In addition, 12 milliliters of a heptane solution containing 24.5 weight percent Al(C 2 H 5 ) 3 and 300 milliliters of dry, oxygen-free n-heptane along with sufficient purple titanium trichloride (obtained from the Stauffer Chemical Company under the designation 2.1AA) is added to provide a weight ratio of 4.5 millimoles of triethyl aluminum per millimole of TiCl 3 . The autoclave was pressured to 280 psig (18.79 atmospheres) with hydrogen and the contents of the autoclave were vigorously stirred while heating to maintain a temperature of 100° C.
After continuing the reaction for 2.5 hours, excess hydrogen was vented and the autoclave contents were drained into 500 milliliters of water. The reactor was then flushed with 700 milliliters of n-heptane, which was then combined with the drained product. Next, 25 milliliters of a 10% hydrogen chloride solution was added to the drained product and the resulting solution stirred vigorously for 2 hours. The resulting organic layer was separated and dried over sodium sulfate. Subsequent filtration yielded a clear, water-white solution, and heptane was removed by means of rotary evaporation.
The weight average molecular weight of the resulting material is estimated to be about 12,000 and contained about 90 percent of a head-to-tail alignment of the repeating units of the molecules forming the oligomer.
The resulting oligomer was blended into a light neutral petroleum oil having a 210° F. viscosity of 4.11 cs., a 100° F. viscosity of 21.62 cs., a viscosity index of 99, and a pour point of -5° F., in amounts sufficient to provide 3.0 weight percent of the oligomer in the neutral oil The foregoing procedure was repeated with varying ratios of purple titanium trichloride to triethyl aluminum. The results are shown in Table I below.
TABLE I__________________________________________________________________________EXAMPLE NO. 1 2 3 4 5 6 7 8__________________________________________________________________________Oligomer Yield 79 84 60 96 97 98 98% of ChargeRatio of triethyl 4.5 3.4 2.7 1.4 0.89 0.45 0.27aluminum/TiCl.sub.3mmole/mmoleOligomer 0 3 3 3 3 3 3 3ConcentrationWt. %Viscosity, cs.0° F. (-17.8° C.) -- -- 2593 2146 2488 2770 3005 3489100° F. (37.8° C.) 21.62 33.09 35.67 33.11 40.35 43.31 50.62 52.67210° F. (98.9° C.) 4.11 6.06 6.60 6.13 7.35 7.94 9.15 9.54Viscosity Index 99 144 154 148 161 169 177 180Pour Point (°F.) -5 0 0 +10 +0 +5 +5 +10__________________________________________________________________________
As seen from Table I, under the heading Example 1, it can be seen that the base oil has a viscosity index of 99. However, with the addition of only 3 weight percent oligomeric viscosity index improver, the viscosity index of the resultant blend was increased to a range of from 144 to 180, which corresponds to an improvement of from 31 to 82 percent in the viscosity index of the blend. Likewise, the addition of the viscosity index improver significantly increased the viscosity of the base oil at each temperature. Thus, for example, the viscosity at 210° F. for the base oil was 4.11, but was increased to from about 6 to 9.54 with the addition of the viscosity index improver Accordingly, Examples 1-8 demonstrate the significant improvement provided by only small amounts of the viscosity index improver of the present invention when utilized with a petroleum oil base stock.
Examples 9-20
A mixture including 1.9 grams of purple TiCl 3 (commercially available from Stauffer Chemical Company as Stauffer 2.1AA), 12 milliliters of a heptane solution containing 24.5% by weight of aluminum triethyl, 250 grams of 1-decene and 250 grams of dry, oxygen-free n-heptane were added to a one-liter stainless steel autoclave that had been previously purged with dry nitrogen. The autoclave was pressured to 200 psig (16.67 atmospheres) with hydrogen, and the contents were vigorously stirred with cooling to maintain the temperature at less than 30° C.
The reaction is exothermic, and when the exotherm had ceased, 100 milliliters of water were added with rapid stirring to decompose the catalyst. Additional n-heptane was then added, the reaction product heated to 60° C., and the solution removed from the autoclave. The resulting material was diluted to a total volume of 3500 milliliters with n-heptane and the organic layer was separated from the aqueous phase. Fifty grams of sodium sulfate were added to the organic solution and the resulting mixture stirred at 80°-90° C. and then filtered to provide a clear, water-white solution. Heptane was removed by means of rotary evaporation and a steam bath.
In order to test the oligomer as a viscosity index improver for synthetic base oils, the liquid oligomer was dissolved in a polyalpha-olefin synthetic fluid that had a viscosity of 8 cs. to provide a 50% by weight concentrate.
Separate portions of the concentrate containing the oligomeric viscosity index improver were blended with a polyalpha-olefin (PAO) synthetic fluid having a viscosity of 4 cs. (commercially available from Chevron Corporation under the trademark "SYNFLUID"). The results are set forth in Table II, below.
TABLE II______________________________________Experimental Blend 1Example No. 9 10 11 12______________________________________1-Decene Oligomer, 0 2 5 10Wt. %PAO Synthetic Base 100 98 95 90StockViscosity, cs., 40° C. 18.431.sup.1/ 26.68 47.61 102.6 100° C. 3.98.sup.2/ 5.99 10.31 21.26Viscosity Index 125 181 213 245Pour Point, °F. -65 -65 -65 -65______________________________________ .sup.1/ 100° F. (37.8° C.) .sup.2/ 210° F. (98.9° C.)
As seen in Table II, the addition of 2, 5 and 10 weight percent of the oligomeric viscosity index improver significantly increased the viscosity index of the synthetic base stock from 125 to from 181 to 245 with no change in the pour point of the resultant lube oil.
For comparative purposes, the foregoing procedure was repeated using a polyalpha-olefin synthetic fluid having a viscosity of 6 cs. The results are shown in Table III below.
TABLE III______________________________________Experimental Blend 2Example No. 13 14 15 16______________________________________1-Decene Oligomer, 0 2 5 10Wt. %PAO Synthetic Base 100 98 95 90StockViscosity, cs.,40° C. 33.82.sup.1/ 50.56 81.85 175100° C. 5.99.sup.2/ 9.51 15.01 31.02Viscosity Index 135 175 194 222Pour Point, °F. -65 -65 -65 -65______________________________________ .sup.1/ 100° F. (37.8° C.) .sup.2/ 210° F. (98.9° C.)
Once again, it is seen that the addition of the viscosity index improver significantly increases the viscosity index of the synthetic base fluid while also building the viscosity of the synthetic base stock.
As a further comparison, the foregoing procedure was repeated with a synthetic fluid having a viscosity of 8 cs., and the test results are shown in Table IV, below.
TABLE IV______________________________________Experimental Blend 3Example No. 17 18 19 20______________________________________1-Decene Oligomer, 0 2 5 10Wt. %PAO Synthetic Base 100 98 95 90StockViscosity, cs., 40° C. 46.46 69.55 114.5 226 100° C. 7.73 11.63 18.77 35.59Viscosity Index 134 163 184 220Pour Point, °F. -65 -65 -65 -65______________________________________
Once again, it is seen that the addition of relatively small amounts of the viscosity index improver of the present invention not only builds the viscosity of the base fluid, but increases the viscosity index to from 134 up to from 163 to 220 depending upon the amount of viscosity index improver. Moreover, it is seen that the addition of only 2 weight percent of the viscosity index improver increases the viscosity index of the base fluid to from 134 to a range of from 163-220.
Examples 21-24
The synthesis procedure of Examples 9-20 was repeated using 222 grams of 1-decene at a reaction temperature of 100° C. for 3.5 hours. The reaction system involved the use of 300 milliliters of n-heptane with a weight ratio of aluminum triethyl to titanium trichloride of 2 to 1.
The hydrogen pressure was 100 psig (6.71 atmospheres). The resulting oligomer was blended with the light neutral mineral oil of Example 1 in a 3% by weight amount.
For comparative purposes, the foregoing procedure was repeated for two additional runs, with the exception that the hydrogen pressure was varied, so that in one run the hydrogen pressure was 150 psig (10 atmospheres), while in the third run, the hydrogen pressure was 400 psig (26.8 atmospheres).
Each of the resulting oligomer fractions was admixed with a sample of the identical light neutral mineral oil of Example 1 using 3% by weight of the oligomer. The resultant blends were tested and the results are set forth below in Table V.
TABLE V______________________________________Oligomer Additives + Light Neutral Mineral Oil BlendsExample No. 21 22 23 24______________________________________Oligomer, Wt. % 0 3 3 3of blendHydrogen Pressure, 100(6.7) 150(10) 400(26.8)psig (atm.)Viscosity, cs.210° F. (98.9° C.) 4.11 6.66 9.44 5.41100° F. (37.8° C.) 21.62 36.73 52.39 29.04Viscosity Index 99 150 178 135Pour Point, °F. -5 -5 -5 -5______________________________________
As seen in Table V, in a comparison of Examples 21 and 22, the use of the addition of 3% by weight of the oligomer of the present invention improves the viscosity index of the base oil from a value of 99 to 150 which constitutes a 51% increase with no detrimental effect on the pour point. As seen in a comparison of Example 21 with Example 23, the oligomer provided using a hydrogen pressure of 150 resulted in an increase in the viscosity index of the base fluid from 99 to 178 which is an 80% increase using only 3 weight percent of the viscosity index improving oligomer of the present invention.
As seen from a comparison of Example 21 with the results in Example 24, where the hydrogen pressure was more than double that of Example 23, the viscosity index of the blend was 135 which constituted a 36% increase in the viscosity index of the base fluid. However, such improvement is below that achieved using a much lower hydrogen pressure for producing the oligomer.
Example 25
The synthesis procedure of Examples 21-24 was repeated using 300 ml n-heptane, 220 g 1-decene, 0.5 g purple TiCl 3 , and 6 ml of a 25 percent by weight solution of triethylaluminum in n-heptane at a reaction temperature of 100° C. and a hydrogen pressure of 380 psig (25.5 atmospheres) for 3.5 hours. The oligomer product had a viscosity of 336 cs. at 210° F. and a sonic shear overall average viscosity loss of 5.2% after 30 minutes of sonic shearing at 100° F., based on 100° F. and 210° F. viscosities of 3 weight percent blends in a light neutral distillate and 4 cs. SYNFLUID® PAO, a synthetic polyalpha-olefin oil.
Example 26
The synthesis procedure of Example 25 was repeated, except that the hydrogen pressure used was 340 psig (22.8 atmospheres). The oligomer product had a viscosity of 406 cs. at 0° C. and a sonic shear overall average viscosity loss of 4.9% after 30 minutes of sonic shearing at 100° F., based on 100° F. and 210° F. viscosities of 3 weight percent blends in a light neutral distillate and 4 cs. SYNFLUID® PAO, a synthetic polyalpha-olefin oil.
Examples 27-37
Examples 27-37 show the oligomerization of 1-decene using a purple TiC13/diisobutyl aluminum hydride catalyst in a molar ratio of 0.94-1.04 moles of diisobutyl aluminum hydride per mole of purple TiC13 The amount of purple TiCl 3 (Stauffer, Grade AA, Type 2.1) employed was equal to 1.0-1.5 weight percent of the 1-decene feed. The oligomerization reactions of Examples 27-37 were carried out according to the following general procedure:
With the exception of Example 35, these reactions were made in a 50-gallon glass-lined Pfaudler stirred tank reactor which had previously been purged with dry nitrogen. The dry, oxygen-free n-heptane solvent was initially added in an amount equal to the decene-1 feed subsequently added. The desired amount of alkyl solution (25 weight percent in n-heptane solvent) was then pressured into the reactor directly from an alkyl cylinder. The TiCl 3 was added into the reactor via a closed addition apparatus that was previously loaded in a controlled nitrogen atmosphere dry box. The slurry of catalyst in solvent was then heated to within a few degrees of the desired reaction temperature in less than an hour's time. At such temperature, dry and oxyen-free hydrogen was injected to pressure the reactor to the desired reaction pressure. Then the dry, oxygen-free decene was metered into the reactor at a constant rate over at least about a forty-minute period, during which time the reaction pressure and temperature were maintained at the desired levels. During the decene feed addition periods of 40 to 55 minutes, for Examples 27-37, temperatures averaged 100° to 115° C. and pressures averaged 77 to 98 psig. The reaction was continued for 90 to 161 minutes after the decene was added. During the post feed addition reaction period, temperatures averaged 100° to 110° C. and pressures averaged 95 to 100 psig. At this point the oligomerization reactions were essentially complete and hydrogen uptake had stopped. The reactants were quickly cooled to about 60° C., depressured, and transferred to a wash tank where the catalyst was removed by repeated washings with dilute aqueous hydrogen chloride solutions. Any residual hydrogen chloride is removed by repeated water washings. The washed product was batch-distilled to a pot temperature of about 175° C. at about 3 mm Hg to remove all the solvent and essentially all the decene not oligomerized. Example 35 was a small scale reaction conducted in a 4-liter stainless steel stirred autoclave. The general procedure used in this small scale reaction was the same as that described below for Examples 38-44. The operating conditions used, however, were in the range noted directly above.
The results of these oligomerizations are set forth in Table VI. As seen in Table VI, the 1-decene oligomers of the present invention exhibit excellent viscosity and shear stability characteristics, as well as a very low bromine index. In addition, the 1-decene oligomers of the invention have very low levels of residual chlorine.
TABLE VI__________________________________________________________________________Oligomerization of 1-Decene Using a PurpleTiCl.sub.3 /Diisobutyl Aluminum Hydride Catalyst__________________________________________________________________________Example No. 27 28 29 30 31 32__________________________________________________________________________Yield, wt. % Decene 71.0 66.3 63.3 75.1 73.5 73.3Viscosity, cs. @ 210° F. 137.6 163 215 331.9 345 369Sonic Shear,30 min at 100° F.Overall Average .sup.(b)Viscosity Loss: % 1.4 1.9 2.8 2.5 3.6 3.6Viscosity Index 1.2 1.3 2.6 0.8 3.8 3.1Loss: %Gel PermeationChromatographyMn 1439 1683 1772 1926 2046 1909Mw 5282 5746 6267 6993 7340 7426Mz 16643 13526 14142 16243 19209 19498Dispersity, Mw/Mn 3.67 3.41 3.54 3.63 3.59 3.89Distribution, Area %28896+ 1.3 1.2 1.5 2.2 2.4 2.422323+ 2.5 2.9 3.7 4.7 5.3 5.48918+ 16.0 19.5 22.4 25.6 27.0 27.41218-8918 59.1 59.1 57.9 57.2 56.7 55.5569-1218 13.6 12.5 11.2 9.8 9.6 9.4<569 11.3 8.9 8.5 7.4 6.7 7.7Bromine Index 232 280 413 306 331 339Chlorine, wt. % <0.01 <0.01 <0.01 <0.01 <0.01 <0.01__________________________________________________________________________Example No. 33 34 35 .sup.(a) 36 37__________________________________________________________________________Yield, wt. % Decene 75.5 74.7 70.3 74.9 73.8Viscosity, cs. @ 210° F. 393.7 420 444 457 459Sonic Shear,30 min at 100° F.Overall Average .sup.(b)Viscosity Loss: % 3.5 3.7 2.6 3.9 4.2Viscosity Index 1.1 -- 2.2 2.5 3.7Loss: %Gel PermeationChromatographyMn 1942 2080 1838 2121 2155Mw 7277 7458 7999 7621 7725Mz 17456 15876 18335 15998 16239Dispersity, Mw/Mn 3.75 3.59 4.35 3.59 3.58Distribution, Area %28896+ 2.3 2.4 3.5 2.5 2.622323+ 5.1 5.4 7.3 5.7 5.98918+ 27.1 28.4 30.2 29.4 29.81218-8918 56.3 56.0 51.8 55.5 55.3569-1218 9.3 9.0 9.4 8.7 8.6<569 7.3 6.6 8.6 6.4 7.3Bromine Index 329 329 216 484 481Chlorine, wt. % <0.01 <0.01 <0.01 <0.01 <0.01__________________________________________________________________________ .sup.(a) 4 l Zipperclave reactor .sup.(b) Based on 100° F. and 210° F. viscosities of 3 wt. blends in a Light Neutral Distillate and 4 centistoke SYNFLUID ® PAO a synthetic polyalphaolefin oil.
Examples 38-44
Examples 38-44 show the oligomerization of 1-decene using a purple TiC13/ethyl aluminum sesquichloride catalyst in a molar ratio of 0.97-1.06 moles of ethyl aluminum sesquichloride per mole of purple TiC13 The amount of purple TiCl 3 (Stauffer, Grade AA, Type 2.1) employed was equal to 0.5-1.5 weight percent of the 1-decene feed. The oligomerization reactions of Examples 38-44 were carried out according to the following general procedure:
With the exception of Examples 39 and 44, these reactions were made in a four-liter stainless steel stirred autoclave which had previously been purged with dry nitrogen. The TiCl 3 was added to the dry reactor via a closed glass ampoule. The reactor was then closed and purged exhaustively with nitrogen before a portion of the dry, oxygen-free n-heptane solvent was added. The desired amount of alkyl solution (25 wt.% in n-heptane solvent) was added to the reactor via a syringe which was inserted through a ball valve on the solvent-decene feed inlet port, while maintaining a nitrogen blanket on the reactor. Another portion of the solvent was then pumped in. Afterward, the ampoule containing the TiCl 3 was broken by turning on the reactor agitator at maximum speed. Then a remaining portion of the solvent was pumped into the reactor. The total amount of solvent was the same as the amount of decene added subsequently. The slurry of catalyst in solvent was then heated to within a few degrees of the desired reaction temperature in less than an hour's time. At such temperature, dry and oxygen-free hydrogen was injected to pressure the reactor to the desired reaction pressure. Then the dry and oxygen-free decene was metered into the reactor at a constant rate over at least about a forty-minute period during which time the reaction pressure and temperature were maintained at the desired levels. During the decene feed addition periods of 37 to 68 minutes for Examples 38-44, temperatures averaged 95° to 100° C. and pressures averaged 88 to 100 psig. The reaction was continued 87 to 90 minutes after the decene was added. During the post feed addition reaction period, temperatures averaged 100° to 105° C. and pressures averaged 94 to 108 spig. At this point, the oligomerization reactions were essentially complete and hydrogen uptake had stopped. The reactants were quickly cooled to about 60° C., depressured, and transferred to a wash tank where the catalyst was removed by repeated washing with dilute aqueous hydrogen chloride solutions. Any residual hydrogen chloride is then removed by repeated water washings. The washed product was batch-distilled to a pot temperature of about 175° C. at about 3 mm Hg to remove all the solvent and essentially all the decene not oligomerized. Examples 39 and 44 were large scale reactions conducted in 50-gallon Pfaudler glass-lined stirred tank reactor. The general procedure used in these two large scale reactions was the same as that described previously for Examples 27-37. The operating conditions used, however, were in the range noted directly above.
These results of these oligomerization reactions are set forth in Table VII. As seen in Table VII, the 1-decene oligomers of the present invention possess excellent viscosity and shear stability characteristics. Moreover, the 1-decene oligomers of the invention have a low bromine index and a low level of residual chlorine.
It has also been found that 3 weight percent of the 1-decene oligomers shown in Tables VI and VII very effectively enhanced the viscosity of the light neutral distillate and the 4 cs. SYNFLUID® synthetic oil in the blends used to measure sonic shear stability. These 1-decene oligomers of the invention blended to a significantly greater viscosity than that predicted, based on the conventional method of calculating the viscosity of a mixture.
Moreover, 3 weight percent of the 1-decene oligomers shown in Tables VI and VII also very effectively improved the viscosity index of the light neutral distillate and the 4 cs. SYNFLUID® synthetic oil in the blends used to measure sonic shear stability.
TABLE VII__________________________________________________________________________Oligomerization of 1-Decene Using a Purple TiCl.sub.3 /EthylAluminum Sesquichloride CatalystExample No. 38 39 .sup.(a) 40 41 42 43 44__________________________________________________________________________ .sup.(a)Yield, wt. % Decene 79.8 76.9 69.5 77.6 70.3 57.5 58.0Viscosity, cs. @ 210° F. 199 337 381 398 482.3 707 825.5Sonic Shear,30 min at 100° F.Overall Average .sup.(b)Viscosity Loss,% 2.31 2.34 2.73 3.87 5.20 3.86 5.53Viscosity Index Loss % 1.97 2.36 2.62 3.37 5.49 3.23 4.75Gel Permeation ChromatographyMn 1250 1724 1574 1615 1547 1978 2053Mw 5988 7488 7890 7193 7800 8967 9547Mz 16273 17785 19573 16159 19543 19938 21094Dispersity, Mw/Mn 4.79 4.34 5.00 4.45 5.04 4.53 4.65Distribution, Area %28896+ 2.2 3.3 3.7 2.5 3.5 4.8 5.722323+ 4.7 6.8 7.4 5.8 7.1 9.4 10.78918+ 21.5 27.3 28.9 27.5 29.6 34.1 36.21218-8918 47.0 52.6 49.4 51.7 49.0 49.4 47.8569-1218 16.5 10.5 10.2 10.2 9.7 8.3 8.1<569 15.0 9.6 11.5 10.6 11.7 8.2 7.0Bromine Index 1723 364 1239 1151 1138 697 410Chlorine, Wt. % 0.12 0.04 0.11 0.10 0.11 0.05 0.03__________________________________________________________________________ .sup.(a) 50Gallon Pfaudler reactor .sup.(b) Based on 100° F. and 210° F. viscosities of 3 wt. blends in a Light Neutral Distillate and 4 centistoke SYNFLUID ® PAO, a synthetic polyalphaolefin oil. | A lubricating oil composition comprising a normally liquid alpha-olefin oligomer consisting essentially of repeating units having the structural formula: ##STR1## wherein x represents an integer from 3 to 11, inclusive; and
y represents the number of repeating units in the oligomer such that the weight average molecular weight is from about 5,000 to about 20,000;
said oligomer having from about 70 to 100 percent head-to-tail alignment of the repeating units of the oligomer. Preferably the weight average molecular weight of the oligomer is from 5,000 to about 10,000; and said oligomer is further characterized as having a dispersity of less than about 5.5, and a Z average molecular weight of less than about 24,000. | 2 |
RELATED APPLICATION
This application is a divisional of U.S. Ser. No. 09/848,626, filed May 3, 2001 entitled “DIFFUSER FOR USE IN A CARBONIC ACID CONTROL SYSTEM” now U.S. Pat. No. 6,568,661 which is incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to pressurized feed systems to treat water and, more particularly, relates to introducing CO 2 into the water to reduce the pH.
BACKGROUND OF THE INVENTION
Raw water may be treated by any number of ways to obtain a final treated water product. However, the final treated water product may have a pH level unsuitable for commercial or consumer requirements. Typically, a final treated water product requires a pH level of less than 9. One method for lowering the pH level in water is to inject CO 2 into the water by a direct gas feed system. The CO 2 is passed through a diffusion system in a recarbonated basin. This diffusion system is commonly referred to as a bubbler. Another method for injecting carbon dioxide into water is to aspirate the carbon dioxide with a venturi. An apparatus using a venturi is sometimes also referred to as a diffuser.
In either method of introducing CO 2 into water, the CO 2 is introduced into a carrier solution to form a carbonic acid solution. To keep the CO 2 in solution and prevent the formation of gas bubbles in the system, the carbonic acid solution is maintained at an elevated pressure. Diffusers are engineered to maintain the system pressure and to distribute the carbonic acid solution into the water being treated. As the pressurized carbonic acid solution is introduced into the water being treated, the CO 2 expands and is released and mixed into the stream of water.
An example of a known diffuser is disclosed in my U.S. Pat. No. 5,487,835, the entire disclosure of which is incorporated herein by reference. In my '835 patent, the diffuser 71 has three rectangular sides defining a triangular prismatic structure. The diffuser 71 is inserted normal to the direction of flow of the water stream. The carbonic acid solution is passed through one end of the diffuser 71 . While the carbonic acid solution is within the diffuser 71 , the diffuser 71 maintains the elevated pressure of the carrier solution forcing the formation of carbonic acid and excess CO 2 , if any, to remain in the carbonic acid solution.
The diffuser 71 has a plurality of outlet holes on two of the rectangular sides. The plurality of holes face upstream while the third rectangular side faces down stream. The passing of the carbonic acid solution through the plurality of holes forces the CO 2 , if any, to be released into the stream of water to reduce the pH. The downstream positioning of the third side without the holes creates a vortex in the stream of water which creates additional mixing.
SUMMARY OF THE INVENTION
The present invention provides an apparatus for adjusting the pH of water using a carbonic acid solution. The diffuser of the present invention maintains the system back pressure when processing the carbonic acid solution and dispenses the CO 2 , if any, to adjust the pH of the water being treated.
In one embodiment of the present invention, the diffuser includes an injector for injecting the carbonic acid solution into a receiver tank. Centrally located within the interior of the receiver tank is a driven impeller. The injector directs the carbonic acid solution towards the impeller. The rotation of the impeller causes the carbonic acid solution and the water within the receiver tank to commingle.
According to another embodiment of the invention, a diffuser of the present invention includes an annular cylinder with a hollow formed therein. A solution inlet permits carbonic acid solution into the annular cylinder. The annular cylinder defines an interior path leading from the inlet, through the hollow, and back to the inlet. A plurality of outlet holes are formed in an upper side of the annular cylinder. The outlet holes permit the carbonic acid solution to flow from the hollow to the exterior of the annular cylinder.
In still another embodiment of the present invention, a diffuser of the present invention includes an elongated body having a hollow therethrough. One end of the elongated body includes an end plate over the hollow. The end plate defines an obround outlet for permitting carbonic acid solution to pass into the water to be treated. The obround outlet is shaped to direct the solution in a particular manner.
In yet another embodiment of the present invention, a diffuser of the present invention includes a pair of laterally displaced nozzles. The pair of nozzles extend into a mixing cylinder and are fixed in a stationary position. The nozzles are oppositely-oriented relative to one another to direct carbonic acid solution passing through each of the nozzles in opposite directions which causes the water and the solution to circulate in the mixing cylinder.
The foregoing has broadly outlined some of the more pertinent aspects and features of the present invention. These should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Other beneficial results can be obtained by applying the disclosed information in a different manner or by modifying the disclosed embodiments. Accordingly, other aspects and a more comprehensive understanding of the invention may be obtained by referring to the detailed description of the exemplary embodiments taken in conjunction with the accompanying drawings, in addition to the scope of the invention defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a front view of one embodiment of a diffuser assembly of the present invention having an injector for directing solution at an impeller.
FIG. 2 is a close-up view of the injector of FIG. 1 .
FIG. 3 illustrates a top view of another embodiment of the present invention having an annular cylinder with a plurality of outlet holes formed in an upper side of the annular cylinder.
FIG. 4 is a side view of the diffuser shown in FIG. 3 .
FIG. 5 is a front view of another embodiment of a diffuser of the present invention having an elongated hollow body, with an obround outlet at one end, positioned within a T-shaped pipe section.
FIG. 6 illustrates a cross-sectional view taken along the line A—A of FIG. 5 .
FIG. 7 illustrates a side view of another embodiment of a diffuser of the present invention having a pair of laterally displaced nozzles adapted to be positioned in a fixed manner in a mixing cylinder.
FIG. 8 illustrates a bottom view of the diffuser of FIG. 7 .
DETAILED DESCRIPTION
Referring now to the drawings in which like numerals indicate like elements throughout the several views, the drawings illustrate exemplary embodiments of the present invention.
In FIG. 1, a diffuser assembly 10 includes an injector 12 for use with a receiver tank 16 . The receiver tank is also commonly referred to as a mixing tank 16 . Within the receiver tank 16 is a motor driven impeller 14 . The injector 12 and impeller 14 are preferably made of type 304 stainless steel. Preferably, a pair of injectors 12 are used with a pair of receiver tanks 16 in a single operation. The injectors 12 in the receiver tanks 16 are assembled alongside one another and operate in a toggling manner. One injector 12 in one receiver tank 16 processes water while the second injector 12 in the second receiver tank 16 is temporarily isolated.
As shown in FIG. 2, the injector 12 includes an elongated member 20 having a solution inlet end 22 and a solution outlet end 24 . The outlet end 24 includes a pair of aligned concentric reducers 26 and 28 . The inner diameter of the narrower reducer 28 is preferably approximately {fraction (33/64)} inches, but may be varied according the specifications of the impeller 14 and the receiver tank 16 . Preferably, the pressure drop through the injector 12 is approximately 44 to 55 psi. An additional reducer, such as concentric reducer 30 may also be used as part of the injector 12 . The bores of each of the reducers 26 , 28 and 30 are aligned with one another to permit each reducer to cooperate with one another to direct the flow of solution through the injector 12 into a stream generally directed at the impeller 14 .
The injector 12 further includes an outwardly extending flange member 32 spaced between the inlet and outlet ends 22 , 24 which is used to connect the injector 12 to the receiver tank 16 as explained below. The diffuser assembly 10 also includes an injector support 34 having an concentric collar 36 configured to surround a mid-portion of the injector 12 and a second outwardly extending flange member 38 mounted to the collar 36 . The injector 12 is adapted to be received in an opening in the side wall of the receiver tank 16 to permit the solution to pass from the exterior to the interior of the receiver tank 16 . The flange member 32 of the injector 12 and the flange member 36 of the injector support 34 abut against one another to retain the injector 12 in the receiver tank 16 . Preferably, the injector 12 is tapped into the side wall of the receiver tank 16 .
The impeller 14 is multi-vaned and is centrally supported within the receiver tank 16 on a distal end 40 of a drive shaft 42 . The drive shaft 42 is coupled to an electric motor which drives the impeller 14 . The vanes of the impeller are oriented to rotate generally about the centerline of the receiver tank 16 . The radial-length of each of the vanes is preferably substantially smaller than the radius of the receiver tank 16 . A proximal end 44 of the drive shaft 42 is supported through the top of the receiver tank 16 by inlet assembly 46 . The injector 12 is positioned in the side wall such that the longitudinal center line of the injector 12 is approximately aligned with the distal end 40 of the drive shaft 42 .
During operation of the diffuser assembly 10 , the water is received into the receiver tank 16 through inlet assembly 46 . Concurrently, the injector 12 injects the carbonic acid solution into the receiver tank 16 . As the water accumulates in the receiver tank 16 , the carbonic acid solution from the injector 12 is aimed at the rotating impeller 14 . The rotation of the impeller 14 causes the solution and the water to be commingled. As the solution and the water is commingled, the carbonic acid with excess CO 2 , if any, mixes with the water, thus reducing the pH of the water in the receiver tank 16 .
As shown in FIGS. 3 and 4, another diffuser 50 of the present invention is shown. The diffuser 50 is for use within a mixing chamber 54 and includes an annular cylinder 52 having a hollow therethrough. A carbonic acid solution inlet 56 is attached to a portion of the exterior circumference of the annular cylinder 52 . The cylinder 52 and solution inlet 56 are preferably made of type 304 stainless steel. The cylinder 52 defines an interior path from the solution inlet 56 , through the hollow, and back to the solution inlet 56 .
The cylinder 52 is oriented in the bottom of the mixing chamber 54 to permit the flow of excess CO 2 upward to the top of the mixing chamber 54 . Preferably, the CO 2 flows upward along substantially the entire height of the mixing chamber 54 . Elongated mounting members 58 act as legs to support the cylinder 52 and extend from an underside 68 of the cylinder 52 . Preferably, the elongated mounting members 58 are spaced equidistant apart from one another as best shown in FIG. 3 . At distal ends 60 of the elongated members 58 are mounting plates 62 for mounting the diffuser 50 with fasteners (not shown) to a surface within the mixing chamber 54 . The mounting plates 62 are also best shown in FIG. 3 . The elongated members 58 and mounting plates 62 are also preferably made of type 304 stainless steel.
An upperside 64 of the cylinder 52 includes a plurality of outlet holes 66 . The outlet holes 66 are preferably spaced equidistant apart and allow the carbonic acid solution to pass from the hollow of the cylinder 52 to the exterior of the cylinder 52 in an even manner.
In operation, the carbonic acid solution is pumped under pressure into the cylinder 52 through the solution inlet 56 . The carbonic acid solution circulates under pressure through the entire length of the path through the hollow. As the carbonic acid solution circulates, portions of the carbonic acid solution pass through the outlet holes 66 in the upperside 64 of the cylinder 52 . As the carbonic acid solution passes through the outlet holes 66 , the pressure of the carbonic acid solution drops causing excess CO 2 , if any, to be forced from the carbonic acid solution. Preferably, the pressure drop is approximately 45 to 55 psi. The carbonic acid solution mixes with the water being treated in the mixing chamber 54 .
FIGS. 5 and 6 illustrate another diffuser 70 of the present invention intended for use with the dirtiest water. The diffuser 70 is preferably used in combination with a T-shaped pipe section 72 . The diffuser 70 also defines a hollow and includes an elongated body 74 having first and second ends 76 and 78 , respectively. An end plate 80 is fastened with fasteners (not shown) or welded to the second end 78 of the elongated body 74 . A front view of the end plate 80 is shown in FIG. 6 and is described in greater detail below. The elongated body 74 and the end plate 80 are preferably made of type 304 stainless steel.
The T-shaped pipe section 72 includes a cross-through portion 82 and a leg portion 84 . The cross-through portion 82 is also typically referred to as the top horizontal portion of a traditionally oriented letter “T”. The leg portion 84 is then the vertically oriented portion of the letter “T”. However, as shown in FIG. 5, the T-shaped pipe section 72 is set on its side and the leg portion 84 is then horizontally oriented.
In FIG. 5, the water being treated is represented by the arrow adjacent the reference letter W. This arrow indicates that the water W is passing through the cross-through portion 82 from a first end 86 to a second end 88 of the T-shaped pipe section 72 . The diffuser 70 is secured at least partially within the hollow portion, on the center line, in the leg portion 84 of the T-shaped pipe section 72 such that the second end 78 of the elongated body 74 of the diffuser 70 is oriented toward the cross-through portion 82 . In FIG. 5, a pair of mounting flanges 90 on the leg portion 84 abut a pair of mounting flanges 92 surrounding the diffuser 70 . Fasteners (not shown) are used to secure the two sets of mounting flanges 90 , 92 together.
As best shown in FIG. 5, the second end 78 of the elongated body 74 of the diffuser 70 is truncated. The second end 78 is truncated to orient the solution passing through the end plate 80 generally counter to the direction of flow through the cross-through portion 82 of the water being treated. However, in some cases, the end plate 80 may be oriented to direct the carbonic acid solution in the same direction as water W. For example, in FIG. 5, there is approximately a 30 degree angle between a vertical line (not shown) passing through the forward tip of the second end 78 and the end plate 80 . This angle may be anywhere in the range of approximately 20 to 45 degrees. The second end 78 should not be parallel to a circle defined by a plane 94 intersecting the hollow in the leg portion 84 of the T-shaped pipe section 72 . Three reference arrows are shown in FIG. 5 to indicate the general direction of the flow of solution from the end plate 80 of the diffuser 70 .
FIG. 6 illustrates a view of the end plate 80 taken along line A—A in FIG. 5 . The outer circumference of the end plate 80 is configured to conform to the second end 78 of the elongated body 74 . The end plate 86 itself defines an obround outlet 98 therethrough. As used herein, the term “obround” means having at least two generally parallel or curved sides 100 and generally semicircular ends 102 , quarter rounded ends, or curved corners. In other words, obround means having periphery segments with rounded intersections. The periphery segments on adjacent sides have unequal lengths, but the periphery segments which oppose one another are generally parallel and are of equal length. The term is thus intended to encompass closed figures having generally opposite sides with rounded corners, generally elliptical closed figures, and generally rectangular closed figures having rounded corners, for example quarter rounded corners. Accordingly, the term obround is meant to be interpreted broadly to cover shapes having cross sections that are generally rectangular, generally elliptical, or generally obround, but have rounded corners to facilitate fluid flow therethrough as described herein.
The obround outlet 98 is larger than the size of an outlet 66 , described above, because the diffuser 70 is intended for use with dirtier water. As explained above, the obround outlet 98 directs the carbonic acid solution passing therethrough into a direction different from the path the solution had taken upon entering the diffuser 70 . In particular, the solution upon passing through the obround outlet 98 is directed counter to the direction of the water W passing through the cross-through portion 82 of the T-shaped pipe section 72 . As before, the carbonic acid solution enters the diffuser 70 under pressure, maintaining the CO 2 in the carbonic acid solution. As the carbonic acid solution emerges from the obround outlet 98 , the resulting pressure differential effectively mixes the carbonic acid solution with the main water stream. Preferably, the pressure drop is approximately 45 to 55 psi. The excess CO 2 is released in generally a direction counter to the direction of the water W. The pH of the water passing through the cross-through portion 82 is reduced as a result of the introduction of the carbonic acid solution.
FIGS. 7 and 8 illustrate yet another diffuser 110 of the present invention. The diffuser 110 includes a pair of nozzles 112 laterally displaced from one another. The pair of nozzles 112 extend into the interior of a mixing cylinder (not shown) which is used for receiving the carbonic acid solution from the diffuser 110 and the water to be treated. An elongated body 114 , having first and second ends 116 and 118 , extends the pair of nozzles 112 into the mixing cylinder. The elongated body 114 includes a hollow therethrough for carrying the carbonic acid solution to the pair of nozzles 112 . The nozzles 112 extend from the second end 118 in substantially a perpendicular manner and remain fixed in a stationary position within the cylinder. The pair of nozzles 112 do not rotate about a central axis of the elongated body 114 . Distal ends 120 of the nozzles are substantially oppositely-oriented relative to one another to direct the solution passing through the nozzles 112 in opposite directions.
As best shown in FIG. 8, each nozzle of the pair of nozzles 112 is defined by elbow portions 122 and concentric reducers 124 . In particular, each nozzle includes a pair of elbow portions 122 defining a semicircular portion. At an end of each semicircular portion is a pair of concentric reducers 124 aligned with one another to direct the solution.
In the preferred embodiment, the diffuser 110 further includes at least one support member 130 for additional structural support within the mixing cylinder and to prevent torque created by the pair of nozzles 112 from twisting the elongated body 114 from the top of the mixing cylinder. In FIG. 7, a pair of support members 130 extend downward from the pair of nozzles 112 and the second end 118 of the elongated body 114 . A mounting flange 132 is then used to secure the support members 130 to the bottom of the mixing cylinder.
In operation, the carbonic acid solution coming from the pair of nozzles 112 causes the water and the carbonic acid solution to circulate in the mixing cylinder. Moreover, the carbonic acid solution enters the diffuser 110 under pressure and, as the solution passes through the pair of nozzles 112 , the pressure differential causes excess CO 2 in the carbonic acid solution to burst forth. Preferably, the pressure drop is approximately 45 to 55 psi. The circulating of the carbonic acid solution with the water caused by the pair of nozzles 112 , as well as the excess bubbles of CO 2 bursting forth, if any, results in the commingling of the carbonic acid solution and the water. The commingling of the carbonic acid solution, excess CO 2 and the water reduces the pH in the mixing cylinder.
In any embodiment of the present invention, the amount of CO 2 which can be mixed with the stream of water or a container of water to be treated at various temperatures and pressures is dependent on the performance characteristics of the CO 2 supply, the carbonic acid solution supply, and in particular, the performance characteristics of each of the diffusion systems as described above.
The present invention has been illustrated in relation to particular embodiments which are intended in all respects to be illustrative rather than restrictive. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. Accordingly, the scope of the present invention is described by the claims appended hereto and supported by the foregoing. | A diffuser for use in a pressurized feed system. The diffuser introduces a carbonic acid solution into water to be treated. The carbonic acid solution within the diffuser is maintained at an elevated pressure. As the carbonic acid solution passes to the exterior of the diffuser, the pressure drop causes an effective mixing of the carbonic acid solution and the water. The carbonic acid solution mixes with the water and the pH of the water is reduced. | 8 |
RELATED APPLICATIONS
This is a continuation-in-part of the inventor's application Ser. No. 98,505, entitled "Apparatus and Method for Under-Water Jacking of Piles", filed on Nov. 29, 1979, and is a continuation-in-part of the inventor's application Ser. No. 3,593, entitled "Apparatus and Method for Driving Members into the Ocean Floor", filed Jan. 15, 1979 now U.S. Pat. No. 4,257,720.
FIELD OF THE INVENTION
The present invention relates to temporary off-shore oil and gas exploration rigs, and, more particularly, to a method and apparatus for anchoring and removing such rigs.
BACKGROUND OF THE INVENTION
When exploring a prospective off-shore oil or gas field, it is customary to use a temporary, portable drilling and production rig of a type commonly known as a jack-up rig. These rigs usually have a floatable deck structure and three or four legs that can be raised and lowered relative to the deck. Thus, the rig can be floated to the drilling site where the legs are lowered to the ocean floor and the deck is raised above the water surface. Ballast tanks carried by the deck are then filled to increase the weight of the rig and thereby set the legs.
Temporary rigs most often rest on spud cans, which are large tank-like structures secured to the bottom ends of the legs. Alternatively, a "mat" may be used, this being a structure that joins the bottom ends of the legs and likewise rests on the ocean floor.
One problem associated with conventional jack-up rigs is that the spud cans tend to sink into the ocean floor, particularly if the rig is left in one position for a long period. It is then extremely difficult to raise the spud cans or mat and float the rig, even after the ballast tanks have been emptied.
Another problem that has potentially more serious consequences arises from the fact that one or more of the spud cans will sometimes break through the strata on which a rig initially rests and sink rapidly to the next high density strata. The rig can then start to lean precipitously, imposing high bending moments on one or more legs. An extremely dangerous condition results. It has also been found that the action of the water sometimes causes scouring in the area around the legs, washing away the surrounding soil and leading to further instability.
Jack-up rigs used for exploration are moved fairly frequently to drill and sample conditions in different areas, usually after one to six months at a single location. It has not been practical in the past to anchor them in the manner of permanent towers that remain in place for periods of several years or longer. These permanent towers are anchored by piles driven along or through the tower legs into the soil below. Usually the piles are driven by an air or hydraulically operated hammer held by a crane on the deck of the tower. More recently, underwater hammers have also been used for this purpose. Anchoring a permanent tower in this way is highly time-consuming and expensive, even in relatively shallow water, and the tower is not usually or readily removed and relocated.
An objective of the present invention is to overcome the above problems by adapting temporary rigs to be anchored by piles. A further objective is to use such piles in a manner that is compatible with the temporary and portable nature of the rigs, thus overcoming the previous objections to the use of piles for this purpose.
SUMMARY OF THE INVENTION
According to the method and apparatus of the invention, a temporary off-shore rig of the jack-up type is towed to an exploration site, the rig having a conventional deck structure attached to three or more legs on which it is to be supported. Preferably, each leg includes a plurality of pile guides, which can also serve as load bearing columns. Within each guide is a pile and a hydraulic jack disposed above the pile.
Once the rig has been positioned so that the foot of each leg rests on the ocean floor, the jacks are extended to push the piles into the soil below. The force required to drive the piles can be monitored and recorded. It is preferable to extend jacks associated with different legs simultaneously to balance the load on the rig.
The most effective technique for achieving penetration by the piles is to use slip mechanisms in conjunction with the jacks, enabling the jacks to be secured to the guides at selected locations. Preferably the guides are tubular to be readily engaged by the slip mechanisms.
After the first extension of the jacks, they are contracted and resecured to the guides. Then the jacks are extended again to push the piles further into the ocean floor. This procedure is repeated until the piles have reached the desired depth.
To retract a pile when it is desired to move the tower, the top end of the jack is secured to the guides while the jack is extended. Then the jack is contracted, pulling the pile behind it. The jack is extended, resecured to the guide and contracted again. This process is repeated until the pile has again assumed its original position fully inside the corresponding guide. As in the case of piles being pushed down into the ocean floor, piles should be withdrawn in sets to balance the load.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a tower of the jack-up rig type constructed in accordance with the present invention, installed at an off-shore location, the deck being positioned near the top of the legs;
FIG. 2 is an enlarged side elevation of the bottom end of one leg of the tower;
FIG. 3 is a cross-sectional view of the leg taken along the line 3--3 of FIG. 2;
FIG. 4 shows a vertical cross section of one cord of the tower, including a pile and a jack mechanism in a contracted position;
FIG. 5 is a cross-sectional view similar to FIG. 4 showing the jack in an extended position;
FIG. 6 is a cross-sectional view of the pile taken along the line 6--6 of FIG. 5;
FIG. 7 is an enlarged cross-sectional view of one of the slip mechanisms indicated by the arrow 6--6 in FIG. 4;
FIG. 8 is a side elevation similar to FIG. 1, but showing the deck near the bottom of the legs to accommodate a low water level;
FIG. 9 is a side elevation of the bottom end of a leg of an alternative embodiment;
FIG. 10 is a horizontal cross-sectional view of a leg (similar to FIG. 3) of an alternative embodiment; and
FIG. 11 is a fragmentary cross-sectional view of a leg of still another alternative embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A temporary rig 10 for off-shore oil and gas well exploration, constructed in accordance with the present invention and shown in FIGS. 1-8, includes a triangular deck structure 12 and three generally vertical legs 14. A three-leg tower 10 is preferred because of its inherent stability and the relative ease of positioning it, but four or more legs can be used, particularly for larger rigs.
The deck 12 supports equipment needed for well drilling and for temporary production while the site is tested and evaluated, as shown in FIGS. 1 and 8. It also supports a control station 16 for the pile jacking operation, which includes the necessary controls and instrumentation in a weather-tight habitat. The rig 10 is suitable for use in 30 to 400 feet of water. The height of the deck 12 above the ocean floor 18 is adjustable in the manner of a conventional jack-up rig, using a rack and pinion mechanism (not shown) in connection with each leg 14. FIG. 1 shows the deck 12 near the top ends of the legs 14 to accommodate a high water level, whereas FIG. 8 shows the deck nearer the bottom ends to accommodate a low water level. Since the legs 14 are adjustable individually, compensation can be made for any variation in the underwater terrain.
Each leg 14 of this exemplary tower 10 is of basically triangular construction, as best shown in FIG. 3. It includes three tubular steel load-bearing columns 20 typically of 1.0 to 2.5 inches in wall thickness, each column being located at one corner of the triangle. Truss members 22 connect the columns 20 for increased rigidity. If desired, each may have more than three columns, some of which are battered.
At the bottom of each leg 12 is a foot 24 adapted to rest on the surface of the ocean floor 18. Each foot 24 is generally similar to a conventional spud can but smaller, not extending substantially beyond the outline of the leg 14 itself, as best shown in FIG. 2.
A tubular steel pile 28 is positioned within each column 20 so that the columns serve as pile guides. Typically, a wall thickness of up to 2.5 inches is suitable for 48-inch diameter piles up to 250 feet in length. The minimum length of the pile 28 should be such that about 50 to 70 feet of pile remain in the column 20 when the pile is extended as fully as anticipated. The bottom end of the pile is equipped with a stab-in cone (not shown) so that the pile will not carry a plug of soil internally when withdrawn.
Each pile 28 is provided with two circular arrays of water jet apertures 29 (see FIG. 6). A lower array of apertures 29 is located about 6 feet from the bottom of the leg 12 and the upper array (not shown) is about 21 feet from the bottom. Each aperture 29 is drilled at such an angle that it forms a tangential extension of the cylindrical inner surface of the pile 28. Thus, water that emerges from the apertures 29 under pressure tends to circulate around the pile 28. The pressurized water is supplied by hoses from a high pressure pump on the corresponding jack 30.
A hydraulic jack 30 is also positioned within each column 20 just above the corresponding pile 28 (see FIGS. 4 and 5). Each jack 30 includes a cylinder 32 within which a piston (not shown) is reciprocable along the generally vertical axis of the corresponding column 20. A rod 36 that extends from the bottom end of the piston engages the top of the pile 28 to exert downward pressure. The rod 36 fits into the top end of the pile 28 and hydraulically retractable dogs 38 on the bottom of the rod engage the underside of a radially inwardly extending flange 40 on the top of the pile 28 so that the piston can exert an upward force on the pile. Thus, exemplary jacks 30 might have an adjustable jacking speed of up to three feet per minute, with a force of up to 1700 tons over an eight foot stroke, while being extended or contracted.
At the top end of each jack 30 are two sets of top slip mechanisms 42 and 44. The upper top set 42 releaseably secures the top (cylinder end) of the jack 30 to the inside surface of the corresponding column 20 to prevent downward movement of the jack 30. The lower top set 44 prevents upward movement.
Each slip mechanism 42 or 44 consists of a ramp 46 immovably secured to the outside of the cylinder 32 and a wedge 48 that fits between the ramp and the inside of the column 20. A small hydraulic cylinder 50 forces the wedge 48 between the ramp 46 and the surface of the column 20 when actuated to cause frictional engagement, thereby immobilizing the cylinder 32 at any desired location.
At the bottom of the rod 36 is a similar set of slip mechanisms 52. These slip mechanisms 52 are oriented to prevent downward movement of the rod 36. They include basically the same arrangement of ramps 46, wedges 48 and hydraulic cylinders 50, as shown in FIG. 7.
An alternative leg construction 54, shown in cross-section in FIGS. 9 and 10, is characteristic of a previously existing jack-up rig that has been modified to incorporate the present invention. Accordingly, spud cans 55 are attached to the bottom ends of the legs 54. These spud cans 55 are larger than the feet 24 described above, and extend well beyond the width of the leg 54 itself, although the spud cans 55 are generally not necessary to the practice of this invention, the smaller feet 24 being adequate.
As in the case of the first leg construction 14, the legs 54 each include three load-bearing columns 56 connected by truss members 58. The leg 54 also includes three separate pile guides 62 each extending along one of the columns 56 inside the truss members 58. An arrangement of piles 66 and hydraulic jacks and slip mechanisms (not shown) is disposed within the guides 62, as in case of the first leg 14. The spud cans 55 can be adapted for use with the invention by providing them with vertical openings 74 aligned with the guides 62 so that the piles 66 can pass through the spud cans into the ocean floor.
It is necessary to position the pile guides 62 outside the columns 56 because of obstructions (not shown) that would prevent the cylinders from moving vertically within the columns. In some pre-existing rigs, however, it may be possible to use a leg construction 69 in which the load bearing columns act as pile guides, as in the leg construction 14. In other rigs, tubular pile guides 70 piles 72 can be positioned within pre-existing columns 74 as shown in FIG. 11.
The method of using the rig 10 is basically the same regardless of which exemplary leg construction 14, 54 or 69 is chosen and will be explained with reference to the construction 12 of FIGS. 1-8. The rig 10 is towed to a preselected well site, where the legs are lowered until the feet 24 come to rest on the ocean floor 16. While the rig 10 is underway, the piles 28 are held in the columns 20 by the bottom slips 52, it being preferable not to hang the piles from the cylinders 32 and rely on the top slips 42 for this purpose.
Once the rig 10 arrives at the site, the deck 12 is jacked out of the water in the conventional manner, as is well known to those skilled in the art and need not be described here. The deck 12 may be positioned near the bottom of the legs 14 for shallow water, as in FIG. 8, or near the top of the legs, as in FIG. 1, for deep water. Whether the water is deep or shallow, it is not necessary to provide a ballast tank to be filled once the rig 10 has been positioned.
Since the columns 20 are pre-loaded with the piles 28 and each column has its own permanently installed jack 30, the rig 10 is ready to be anchored as soon as the legs 14 are lowered to the ocean floor. Thus, the weather window required for installation of the rig 10 is reduced to a minimum and the safety factor of the entire installation process is increased accordingly.
The piles 28 are pushed into the ocean floor 16 by extending the hydraulic jacks 30 from the position of FIG. 4 to the position of FIG. 5. As the jacks 30 are extended, they are held against upward movement within the columns 20 by the lower set of top slips 44 and against downward motion by the upper set of top slips 42. Next the slips 42 and 44 are released and the jacks 30 are contracted, while the rods 36 and the piles 28 are held against downward movement by the bottom slips 52. It is necessary to guard against uncontrollable downward movement since the piles 28 could sink rapidly under their own weight in soft soil.
The jacks 30 then are resecured to the columns 20 by reactivating the top slips 42 and 44, and the jacks are extended again to push the piles 28 further into the ocean floor 16. This procedure of expanding and contracting the jacks 30 is repeated until the desired pile penetration has been reached to provide the necessary bearing capacity. If a storm should arise when the jacking of the piles 28 has not been completed, the tower 10 can be secured to the piles and prevented from being lifted by wave motion by actuating the bottom slips 52.
Jacking the piles 28 into the ocean floor 16 has a number of advantages when compared to the conventional use of a hammer to drive the piles by impact. The piles 28 are not subjected to lateral movement due to bending or outward radial expansion. Therefore, the surrounding soil 16 maintains a tighter grip on the piles 28, producing greater holding power for each foot of penetration. In addition, the energy input is more effectively employed when the piles 28 are jacked hydraulically because the piles do not dissipate the energy by flexing. Moreover, the hydraulic jacks 30 operate effectively under water, whereas a conventional air or hydraulic hammer could not.
It will be noted that the force required to drive each pile 28 can be readily monitored and recorded, with precision, and compared to the penetration of the pile. This information gives an accurate indication of the bearing capacity of the pile 28, which can be computed continuously as the pile is driven. Pile penetration can be determined from the flow of hydraulic fluid in the jacks 30. One important advantage of these calculations is that they permit an on-site determination of the depth to which each pile 28 must be driven to obtain the bearing capacity required. The waste inherent in driving the piles 28 to predetermined depths, rather than until a desired bearing capacity has been attained, is thus eliminated.
It is also possible to periodically verify the bearing capacity of the piles 28. This is accomplished by slowly increasing the pressure of the jacks 30 on the piles 28 until small incremental movement of the piles is observed. If insufficient resistance is encountered, the pile 28 is then known to be inadequately supported by the soil below. Further required penetration can be calculated and subsequently obtained.
Although the rig 10 is intended for temporary installation, it can, unlike conventional jack-up rigs, be converted to permanent installation once the exploration of the area is completed. For permanent installation, the piles 28 should be grouted to the columns 20 or other pile guides.
A particularly important advantage of jacking the piles 28 into the ocean floor 16 is that the same jacking mechanisms 30 are used to withdraw the piles into the columns 20 or other pile guides when it is desired to remove the rig 10. First, however, water is forced out through the apertures 29, shown in FIG. 6, to loosen the piles 28. This jetting operation, which continues during the first stroke of the jacks 30 is desirable because a pile 28 that has been in place for a significant time may otherwise require an initial pull-out force of two to three times the push-in force.
The jacks 30 are positioned near the bottom ends of the columns 20 and are extended upwardly. The upper set 42 of top slip mechanisms is activated to secure the jacks 30 to the columns 20 and then the jacks are contracted to raise the piles 28. Since the piles 28 typically offer little resistance to being pushed back down, the jacks 30 should be secured to the columns 20 by the bottom slip mechanisms 52 before they are expanded to raise the piles by another stroke. After the jacks 30 have been extended again, and resecured to the columns 20 at their top ends to prevent upward movement, the piles 28 are raised another stroke, and this process is repeated until the piles have been fully withdrawn into columns 20.
It is preferable that the jacks 30 always be actuated in sets that apply a balanced load to the rig 10. If an unbalanced load were applied, the piles 28 would tend to bend and bind against the soil, making penetation or withdrawal more difficult. In the case of the three-legged rig 10, one pile at each leg 12 should be part of each set. The tower described here would thus have three sets of piles 28, each set including one pile at each leg 14. Of course, the number of sets would vary with the number of piles 28 at each leg 14.
In the case of a four-legged rig (not shown), it is not necessary to move piles at all four legs simultaneously. Instead, balanced loads can be produced by moving piles at diagonally opposite legs.
It will be appreciated that the invention permits temporary rigs to be held by piles, giving them stability and safety previously possible only with permanent towers. At the same time, the rig of the invention is easily and quickly anchored and removed in a manner not previously possible in the case of towers anchored by piles.
While a particular embodiment of the invention has been illustrated and described, it will be apparent that various modifications and changes can be made without departing from the spirit and scope of the invention. | A temporary rig of the jack-up type for oil and gas exploration. The rig is towed to a selected site where the legs are lowered to the ocean floor and the deck is raised out of the water. Piles are then pushed into the ocean floor by a series of extensions of hydraulic jacks to anchor the legs. The piles can be pulled up by contracting the jacks in a similar manner so that the rig can be moved to a new location. The jacking mechanisms move within pile guides that form parts of the legs. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for plating minute parts whereby a plated layer of a precise and uniform thickness can be formed even in a minute area part of a specific part of a member to be plated.
Nowadays, a partial plating of only a specific part of a member to be plated is considered to be important in respect of its function and resource saving and is indispensable particularly to the electronic industrial field.
As well known, in integrated circuit elements, various semiconductor elements, printed base plate fitting minute electronic parts, displaying elements and highly integrated printed base plates, it is important to inhibit as much as possible resistances and reactances at the respective terminals, contacts and electrode points and to control unnecessary voltage drops, electric power losses, noise generations, circuit time constant variations and influences on other circuits.
Therefore, in the above mentioned respective electronic parts and printed base plates, it is necessary to use such metal high in the conductivity and anticorrosion as such precious metal as, for example, gold Au, platinum Pt, silver Ag or rhodium Rh. However, these metals are materials so costly as to be applied by a jetting type partial plating means which can plate only really necessary parts and uses a slight amount of the plating mother material. In the partial plating means in the prior art example, a plating liquid jetting nozzle and a mask enclosing a specific part of a member to be plated are provided and the plating liquid jetting nozzle and the member to be plated are made electrodes.
The flow of the metal ions in the plating liquid is a sum of a migration by the electric field, a diffusion by the concentration variation near the electrode and a convection movement proportional to the flow velocity of the plating liquid but the concentration variation particularly near the electrode will inhibit the reaction velocity and reduce the current efficiency.
Therefore, the above mentioned prior art example has such defects as are described below:
(1) After the plating liquid collides with the surface to be plated, it is so difficult to control the flow velocity that the area wet with the plating liquid will expand to be larger than the opening area of the mask and it will be difficult to accurately plate only the really required minute area part.
(2) The feed of the metal ions in the plating liquid is so low as to be of a low current density of about 20 to 30 A./dm 2 . that the plating time will be long and the current fluctuation during the plating will be so large that the plated thickness will be likely to become nonuniform.
(3) Even if the member to be plated is plated while masked correspondingly to its form, the flow volume of the plating liquid will be difficult to control, the adjustment of the distance between the nozzle and the member to be plated will be limited, therefore an inaccurate definition will be likely to occur, the plating specks will be produced, the plating boundary will become unclear and the plating mother material will be consumed more than is necessary.
(4) In the case of changing the mask in response to the kind of the member to be plated, not only the mask exchanging work but also the adjustment of setting the nozzle and mask will be difficult, a so-called preparation time will be taken, the workability will be low and therefore it will not be adapted to a small production of many kinds.
(5) In the case of continuously partly plating such long members to be plated as hoop members, the nozzle masking system as well as the plating liquid feed controlling system will be made a multi-system. However, in the multi-system, the distance between the member to be plated and the nozzle, the flow volume and velocity of the plating liquid and the volumes of the sucked and exhausted gases will be likely to fluctuate and they will be so difficult to adjust that the quality of the plating of the plated products will be so difficult to control as to be a great obstacle to the mass production.
(6) As mentioned above, the plating time is so long that the entire plating apparatus will become large, the control system will be complicated, therefore the equipment cost will be high, the occupied setting area will become large, the maintenance will be difficult and, in the case of newly providing, increasing, improving or moving the equipment, a great problem will come out.
(7) As the rate of yield will reduce due to the fluctuation of the quality of the plating and, as the step and quality controlling workers, many steps, excess jigs and examining equipments are required, the running cost as well as the equipment cost will be high.
On the other hand, as the current passing capacity in the above mentioned electronic part is usually about several μA. to several +mA., for example, the precious metal plating of the contact part will be enough with a diameter of less than 1 mm. and a thickness of several μ. Also, as in the lead frame of the integrated circuit (IC) element, when many conducting parts of a minute width are arranged very adjacently, it will be enough to plate the terminal with gold of a diameter of about 0.2 mm. and a thickness of about 1μ.
Thus, the plating of a minute amount will do but, in the partial plating means of the prior art example, as there are such problems as are mentioned above, the consumption of the costly precious metal will be more than is necessary, the plating quality and precision will be low and, as the mass productivity is none, the mass production of cheap products will be greatly obstructed.
In view of such problems as in the above, "A method and apparatus for plating minute areas" are suggested in Japanese Patent Application No. 100772/1979. "A plating process" by U.S. Pat. No. 4,287,029 and "A plating means" by U.S. Pat. No. 4,348,267 are suggested.
That is to say, in plating a part to be plated by jetting a plating liquid onto the part through a tapered through hole formed in a mask opposed to a nozzle, outside air or a compressed gas is made to flow in through an air passage formed in the mask so as to communicate with the above mentioned through hole in the direction substantially at right angles with the direction of the nozzle so that the jetted plating liquid will be quickly prevented by the gas flowing in from staying in the through hole part, the current density will be elevated and the used plating liquid jetted onto the part to be plated will be sucked by a sucking device through a discharging pipe in the rear of the nozzle, the chamber including the nozzle will be under a negative pressure and thereby the used plating liquid discharging velocity will be increased. Thus, the minute part can be plated to be high in the precision and quality.
However, in case the object to be plated is such as each lead tip of an integrated circuit lead frame, if the nozzle is made in a multi-system as described above, the entire structure will be so minute and the distance between the electrodes will be so close that there will be such problems as in the following.
There has been a problem that, in the case of forming the air passage in the mask, a high working precision will be required and the mask making and plating costs will be high.
Also, as the air passage communicating with the outside is formed in the mask so that outside air or a compressed gas may be introduced to the through hole side, the absolute value of the negative pressure within the chamber under the negative pressure in advance will become small and the distance between the nozzle and the object to be plated will be so small that, in case the above mentioned gas flows in or the plating liquid is jetted onto the part to be plated from the nozzle, it will be subjected to a resistance, the plating liquid jetting velocity will reduce and it will be necessary to pressurize the plating liquid tank or to elevate the static position potential.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus for plating minute parts wherein a plating liquid after being jetted onto a part to be plated is quickly discharged to elevate the plating velocity.
Another object of the present invention is to provide a minute part plating apparatus whereby a minute part can be precisely plated by preventing an inaccurate definition.
A further object of the present invention is to provide a minute part plating apparatus wherein a plating liquid can be continuously re-used.
Further, other objects, features and advantages of the present invention will become apparent enough with the following explanation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectioned view showing the peripheral part of a mask and nozzle system in a prior art example.
FIGS. 2 and 3 relate to the first embodiment of the present invention.
FIG. 2 is a sectioned view showing the peripheral part of a mask and nozzle system in the first embodiment.
FIG. 3 is a sectioned view showing a mask part as magnified.
FIG. 4 is a sectioned view showing the peripheral part of a mask and nozzle system in the second embodiment of the present invention.
DETAILED DESCRIPTION
Prior to explaining the embodiments of the present invention, the conventional example of a minute part plating apparatus shall be explained with reference to FIG. 1.
In this minute part plating apparatus, a nozzle 2 for jetting a pressurized plating liquid is removably secured to a jacket tube 5 provided with a chamber 3 of a predetermined capacity and a discharging pipe 4 communicating with it.
Also, a mask 8 in which a through hole 7 facing the tip of the above mentioned nozzle 2 is formed is removably secured to the top of the above mentioned jacket tube 5 so that, in the case of a plating treatment, a member 9 to be plated will be arranged in contact with this mask 8 and, in the case of plating, the nozzle 2 will be connected to a + pole of a direct current source and the member 9 to be plated will be connected to a - pole of the same. Further, in the case of melting a metal or the like on the surface of the plated member 9, that is, in the case of reverse plating, the polarities of the direct current source may be reversed with each other. By the way, an air passage 10 communicating with outside air is formed in the mask 8 as to be connected with an outside piping (not illustrated) in case a compressed gas (air or an inert gas) is made to flow in.
Further, a discharging pipe 4 is connected with an exhaust pump (not illustrated). In the above described plating apparatus 1, in the case of the plating treatment, the exhaust pump will be driven to hold the chamber 3 and discharging pipe 4 under a negative pressure so that, when the direct current source is impressed, outside air or the compressed gas will be made to flow in through the air passage 10 and a plating liquid will be jetted from the nozzle 2. This plating liquid will collide with the member 9 to be plated through the mask 8 while in the form of a pillar of a thickness approximate to the inside diameter of the nozzle. At this time, a metal will be deposited on the member 9 to be plated and the part corresponding to the through hole 7 will be plated.
Also, the outside air or compressed gas flowing in through the air passage 10 will concentrate near the through hole 7 and will flow into the chamber 3, therefore the plating liquid will be prevented from being diffused, the concentration on the member to be plated will become high, the current density will also rise and therefore the plating quality will be improved and stabilized.
Further, as the discharging pipe 4 and chamber 3 are under the negative pressure and the outside air or compressed gas flows in through the air passage 10, the plating liquid jetted from the nozzle 2 will be quickly forcibly discharged after being used.
Therefore, the bonded surfaced of the mask 8 and the member 9 to be plated will be wet and will prevent the plating liquid from penetrating out and therefore an inaccurate definition will be able to be prevented.
Further, as a fresh liquid phase is always on the boundary of the member to be plated (a solid phase) and the plating liquid (a liquid phase), a diffused layer likely to be produced on this boundary will become so thin that the ion concentration will become uniform and, the same as forming an electrolyte pillar formed of only a specific electric resistance inherent to the plating liquid, the current value will become constant and stable, therefore the depositing velocity of the metal will be also stabilized and a high quality plating will be obtained.
However, in case the object to be plated is such as each lead tip of an integrated circuit lead frame, there will be the above described problems.
The present invention is to solve the above mentioned problems to make it possible to plate even minute parts to be high in the precision and quality.
In the following, the embodiments of the method and apparatus for plating minute parts according to the present invention shall be explained with reference to FIG. 2 and others following it.
As shown in FIGS. 2 and 3, a through hole 13 tapered in the form corresponding to an object to be plated is made in a mask 12 closely fittable to an object 11 to be plated. This mask 12 is secured on the stem side to a jacket tube 14.
A chamber 15 of a predetermined capacity is formed in the jacket tube 14. A nozzle 16 opposed to the above mentioned through hole 13 and a nozzle holder 17 are arranged in the bottom of the chamber 15. The nozzle holder 17 is made free to rise and fall while holding the nozzle 16 so that the distance between the object 11 to be plated and the nozzle 16 (which distance shall be called an inter-electrode distance hereinafter) can be adjusted.
Any number of discharging pipes 18 for discharging the plating liquid as described later are passed through the side wall of the bottom of the jacket tube 14. This discharging pipe 18 is connected at the end to a sucking device (not illustrated) through a plating liquid separator (not illustrated) so that the discharging pipe 18 and chamber 15 may be set under a negative pressure of a predetermined value.
By the way, the above mentioned nozzle 16 is connected at the rear end to a plating liquid tank connected to the plating liquid separator so that a reproduced plating liquid may be added. Further, as required, for example, in case a back pressure is produced by the plating liquid near the nozzle 16 and the subsequent plating liquid pressure can not resist it, the position of setting this plating liquid tank will be elevated so that a pressure may be given to the plating liquid by the potential energy or a pump will be provided between the nozzle 16 and the plating liquid tank to pressurize the plating liquid or to set the plating liquid tank under a high pressure.
Also, the nozzle 16 is connected to the + pole of the direct current source so as to be on the anode side and the object 11 to be plated is connected to the - side so as to be on the cathode side.
There shall be explained in the following the operation of the method and apparatus of the first embodiment of the present invention wherein thus a specific part of the object 11 to be plated is enclosed with the mask 12 to form a plating treating part by the masking means, the mask 12 is brought into close contact with the object 11 to be plated to hold the chamber 15 within the jacket tube 14 in a sealed space, the plating liquid is jetted under a predetermined pressure from the nozzle 16 forming a plating liquid jetting means within the sealed space, the nozzle 16 is made an anode, the object 11 to be plated is made a cathode to plate the specific part of the object 11 to be plated and the sealed space is held under a negative pressure by the discharging means through the discharging pipes connected to the above mentioned sealed space so as to discharge the used plating liquid.
When the mask 12 is brought into close contact with a predetermined part of the object 11 to be plated, the interior of the mask 12 and jacket tube 14 will be a sealed space.
Under this state, the plating liquid is jetted onto the object 11 to be plated through the through hole 13 of the mask 12 from the nozzle 16 so as to deposit a metal. This used plating liquid is forcibly and quickly discharged through the discharging pipes 18 through the chamber 15 by the negative pressure. At this time, the metal will be deposited on the object 11 to be plated but the plating liquid will penetrate also to the contact surface of the mask 12 and the object 11 to be plated.
However, as well known, the flow velocity of the plating liquid jetted from the nozzle 16 will be fastest in the center part but will be slow in the peripheral part. However, if 0.5<B/b≦3 where B represents the area of the hole of the nozzle and b represents the area of the through hole of the mask, a fresh plating liquid will be always fed through the through hole 13 of the mask 12 and the thickness of the diffused layer will reduce and the metal will be effectively deposited, whereas, on the outer periphery of the through hole 13, the penetrating plating liquid will be a back pressure, no subsequent plating liquid will be fed and no optimum plating condition will be established.
As shown in FIG. 3, if the inside radius of the nozzle 16 is represented by R, the radius of the through hole 13 of the mask 12 is represented by r and the distance of the nozzle from the mask 12 is represented by L, the distance l 1 from the periphery of the nozzle 16 to the center of the object 11 to be plated will be l 1 =√L 2 +R 2 .
On the other hand, the distance l 2 from the periphery of the nozzle 16 to the inside edge of the through hole 13 of the mask 12 will be l 2 =√L 2 +(R-r) 2 and, if the inter-electrode distance between the nozzle 16 and the object 11 to be plated is short, l 1 ≈l 2 .
Therefore, within the range regulated by the through hole 13, the difference between the specific resistance values will be so small that the plating current density will be uniform but, on the contact surface of the mask 12 and the object 11 to be plated, the edge surface distance from the inside edge of the through hole 13 will increase, therefore the specific resistance will become larger than that of the center part and the plating current density will remarkably reduce. As a result, the metal will be deposited only on the part opposed to the through hole and a mesa-shaped plating having an accurate definition will be obtained.
On the other hand, if the inter-electrode distance is extremely contracted, the electric field intensity between both electrodes will become large. When a voltage of 1 V. is applied to a tank of an inter-electrode distance of 1 cm., the average velocity of ions moving toward the electrodes will be v/V.
A formula v/V=λ/F (where λ represents a value of an equivalent ionic conductance divided by 1 Faraday) well known as of an ionic mobility will be established. If a voltage of 100 V. is applied to an inter-electrode distance of 1 cm. by using the above formula, with silver ions, the mobility will be about 0.08 cm 2 ./sec. V. at the maximum (at a temperature of 75° C.). Usually the offshore ionic mobility can be neglected. However, as the value of the diffusing velocity D cm 2 ./sec. (varying with the temperature and concentration) produced from the concentration gradient is about 1 to 5×10 -5 cm 2 ./sec., even if the inter-electrode distance is about 0.1 to 2 mm. and the plating voltage is about 1.5 V., the electric field intensity will be 150 to 8 V./cm., the ionic mobility will be about 0.12 to 0.0064 cm 2 ./sec. and this value in the diffused layer near the cathode will be over the diffusing velocity.
As a result, the limiting current density in the diffusion rate determining process will be given by i lim =[(n F D C b )/δ] (where n represents an ionic value, F represents a Faraday constant, D represents a diffusion coefficient, δ represents a thickness of a diffused layer and C b represents an offshore concentration). However, D in the present invention will be the ionic mobility+diffusing velocity and a very large current density will be obtained.
In the case of the present invention, the velocity of the plating liquid on the cathode surface will be higher than in the case by the outside air introducing system shown in FIG. 1 and, even if the thickness of the diffused layer somewhat increases, D in the above mentioned formula will be able to be taken to be large enough to obtain a high current density.
On the other hand, in the part penetrated from the through hole of the mask, the distance along the surface from the anode will be large, the IR loss will increase, the plating potential will reduce to be a voltage extremely high in the depositing velocity or below the metal decomposing voltage and the metal will not be substantially deposited. Therefore, a plating having an accurate definition will be obtained.
As described above, in the present invention, the inter-electrode distance between the nozzle 16 and the object to be plated is so short and has such large relation with the current density distribution of the object to be plated as to be important to set. Therefore, in either a single plating device or a series of many plating devices, the inter-electrode distance may be finely adjusted with the nozzle holder 17.
Further, in case the object to be plated has a curved surface, for example, in the case of such electric contacting piece (the object to be plated) 20 as is illustrated in FIG. 4, a curved mask body 21 to be in close contact with the curved surface as in the second embodiment shown in FIG. 4 is secured to a mask supporting member 22 and a communicating through hole 24 opposed to a nozzle 23 and having a diameter substantially equal to the inside diameter of the nozzle is made through the mask body 21 and mask supporting member 22.
The tip of the nozzle 23 is formed to be of a curved surface similar to the surface to be plated of the object 20 to be plated and the distance between each point of the opening edge of the nozzle and the surface to be plated is made constant.
Now, the plating liquid jetted from the nozzle 23 will contact the object 20 to be plated through the communicating through hole 24 of the mask body 21 and mask supporting member 22, will deposit a metal and then will be quickly discharged through the discharging pipes 18. Therefore, the same as in the first embodiment, a plating layer having a curved surface corresponding to the curvature and a uniform thickness will be produced on the object 20 to be plated.
In both of the above mentioned first and second embodiments, when sealed spaces are formed by bringing the mask 12 and mask body 21 into close contact respectively with the objects 11 and 20 bo be plated and are held under a negative pressure, a mesa-type minute part plating having an accurate definition will be obtained. What are important in the present invention are to make the respective inter-electrode distances respectively between the nozzles 16 and 23 and the objects 11 and 20 to be plated very short, to positively utilize the migration by the electric field and to elevate the flow velocity of the plating liquid.
Therefore, as mentioned above, it is very important to set the inter-electrode distance. If the inter-electrode distance is short, the used plating liquid discharging velocity will be necessarily a problem. In the present invention, the value of the negative pressure within the chamber can be properly set in response to the kind or form of the plating liquid, dimension, single plating treatment or series of many simultaneous plating treatments.
Needless to say, the minute part plating apparatus according to the present invention can be utilized for the minute area plating apparatus according to the above mentioned prior art example (Japanese Patent Application No. 100772/1979) and concretely, when it is to replace the mask-nozzle system, it will be very useful.
As described above, according to the present invention, the mask is brought into close contact with the object to be plated to form a sealed space and the inter-electrode distance between the nozzle and the object to be plated is made short to positively accelerate the electric field migration and to forcebly discharge under a negative pressure the used plating liquid after being jetted from the nozzle to plate the object so that there may be remarkable effects that the (absolute value of the) negative pressure value can be made large by the discharging means utilizing outside air, the velocity of the plating liquid can be made high, the plating efficiency by the increase of the current density can be made very high by the effect of the ionic mobility by the above described electric field intensity, it may not be necessary to provide an air passage which must be worked at a high precision in the mask and not only the mask manufacturing cost but also the plating cost will be low.
Also, in the method formed in the apparatus of each of the above described embodiments wherein the inter-electrode distance between the nozzle 16 or 23 and the object 11 or 20 to be plated is made short enough to be adjustable and is therefore set and adjusted as required, the plating liquid is jetted, the used plating liquid is forcibly discharged by holding the rear of the nozzle under a negative pressure and therefore the plating velocity can be made high.
By the way, it is apparent that working modes different in a wide range can be formed without deviating from the spirit and scope of the present invention. The present invention is not restricted by its specific working mode except being limited in the appended claims. | Here are disclosed a method and apparatus for making it possible to plate specific parts of members to be plated to be high in the precision and quality even in minute area parts.
In highly integrated printed base plates and integrated circuit elements, it has been difficult to plate precious metals high in the specific conductivity precisely and uniformly in the required minute parts with a plating apparatus in order to control as much as possible the resistances and impedances in the respective terminals and contacts. Therefore, according to the present invention, in a jetting type plating apparatus jetting a plating liquid through a nozzle onto a specific part required to be plated of an object to be plated, a mask is brought into close contact with the periphery of the specific part opposed to the nozzle to form a sealed space around the nozzle by a closely enclosing means, the object to be plated is set at a distance adjacent to the nozzle tip, a voltage of a predetermined polarity is impressed to make the migration of metal ions by an electric field conspicuous, to make a plating treatment possible and the sealed space is held under a negative pressure to quickly suck and discharge the used plating liquid. | 8 |
CONTINUITY
[0001] This application is a continuation application of Utility patent application Ser. No. 14/474,833, filed on 09/02/2014, which is a non-provisional application of provisional patent application No. 61/962,092, filed on Oct. 31, 2013, and priority is claimed thereto.
FIELD OF THE PRESENT INVENTION
[0002] The present invention relates to maintenance and cleaning products, and more specifically, those products designed to facilitate the cleaning and removal of animal fecal matter from an unwanted location on land or flooring.
BACKGROUND OF THE PRESENT INVENTION
[0003] Pet owners are well aware that pet ownership comes with certain responsibilities. Standard care practices of feeding, providing water, nurturing, and veterinary services are well known. Additionally, disposal of the pet's waste, especially the waste of dogs, is a chore of most pet owners. If the pet owner lives in a city or similar urban or suburban environment where large amounts of private land are uncommon, it is frequently required by law for pet owners to manually dispose of his or her pet's waste, especially if the pet defecates on public or government land.
[0004] Manually disposing of the pet's waste is unfortunate for the pet owner, as it requires additional labor to clean up, and the pet owner is potentially subject to contaminated fecal matter. Currently, there are two primary means of collecting pet waste for disposal—namely, a scoop, such as a conventional “PooperScooper,” or simply a plastic bag in the hand of the pet owner.
[0005] Frequently, bag dispensers are sold to facilitate the release of a bag and to minimize the space occupied by the bags during the walk. Unfortunately, nearly all of the bag dispensers or bag set-ups still require the pet owner to physically pick up the pet's waste with his or her hand, the only protection on the hand being the bag. Many pet owners find the warmth of pet waste one of the larger drawbacks to collecting pet waste in this fashion. A claw or “PooperScooper” type of product can help to eliminate this, however it would require frequent cleaning, and the user is still required to remove the excrement from the claw, and place it into a bag. This process may cause the user to spill the bag, exacerbating the process, and potentially soiling the hands of the user.
[0006] Thus, there is a need for a device which can automatically pick up pet waste into a sealed bag without the pet owner coming into remote contact with the pet waste. Such a device preferably employs a bag cartridge system, enabling the user to install a bag cartridge to a rim of the device. The bag is preferably air-permeable, such that the suction of the vacuum employed is not diminished during use.
SUMMARY OF THE PRESENT INVENTION
[0007] The present invention is an animal waste vacuum disposal and bagging device. The present invention is configured to provide the user, preferably a pet owner or pet care provider, a practical, convenient, and sanitary means of collecting pet waste such as feces, without the need to ever come into contact with the waste. Via the present invention, it is envisioned that the user need not ever come into contact with pet waste. The present invention is configured to be convenient to carry along during a walk, and is preferably recharged between walks in order to keep the battery at full capacity.
[0008] The preferred embodiment of the present invention is equipped with a vacuum motor, bag (in communication with a bag cartridge), and a canister. The vacuum motor of the present invention is preferably activated via a power button which is pressed by the user at his or her will. The vacuum motor of the present invention is preferably housed within the canister, and provides suction to the bag. A suction exhaust vent is preferably present on the exterior of the canister. Upon activation of the vacuum motor of the present invention, the pet waste is suctioned into the canister, and is caught within the bag.
[0009] When the pet waste arrives within the bag, preferably of a proprietary design integrated into a bag cartridge, it is then promptly sealed via adhesive to eliminate the potential for odor or leakage from the bag. As such, the design of the bag cartridge is unique, and may not be replaced with a conventional plastic bag. After collection of the pet waste is completed, the user deactivates the present invention with the power button, and a door preferably seals over the rim of the collection chute of the canister, maintaining the bag and waste within the device. The user is now free to continue the walk with his or her pet. Upon arrival at a garbage can, the user presses a dispose button. The dispose button is preferably located next to the power button. Upon activation of the dispose button, the collection chute releases the full, sealed bag containing the pet waste into the garbage can.
[0010] A pet owner using the present invention would never be required to come into contact with fecal matter, and the pet owner could simultaneously rest assured that the pet waste had been properly disposed of, preventing health threats to members of the community, as well as other animals. The present invention is designed to be ideal for use by pet owners who reside in cities where city statures and laws require pet owners to remove of all pet waste created by pets. Use of the present invention by pet owners makes the process of pet waste disposal less embarrassing, safer, and easier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows the present invention as viewed from the side.
[0012] FIG. 2 exhibits a top view of the bag cartridge of the present invention.
[0013] FIG. 3 displays a view of the bag cartridge of the present invention as seen from the side when flattened for storage.
[0014] FIG. 4 shows a view of the bag cartridge of the present invention as seen from the bottom when flattened for storage.
[0015] FIG. 5 depicts a view of an alternate embodiment of the present invention, showing a mechanical switch to facilitate separation of the bag cartridge from the rim of the collection chute.
[0016] FIG. 6 shows a view of an alternate embodiment of the present invention, showing the internal clamp used to seal the bag within the collection chute after waste collection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The present invention is an adjustable and adaptive vacuum and bagging device that facilitates the secure collection and transport of pet waste. The present invention facilitates the process of collecting and disposing of pet waste varying in size without the user ever having to touch the waste, nor the bag containing the waste, during neither the collection nor the disposal process. The present invention is preferably equipped with a canister ( 10 ), a bag ( 170 ) housed within a bag cartridge ( 220 ), a battery ( 30 ), a battery compartment ( 40 ), a handle ( 50 ), a power button ( 60 ), a dispose button ( 70 ), and a vacuum motor ( 80 ). The battery ( 30 ) of the present invention is preferably rechargeable, and is preferably recharged within the battery compartment ( 40 ) via an external, conventional AC/DC adapter. The handle ( 50 ) of the present invention is preferably equipped with a contoured grip. Some embodiments of the present invention may be equipped with a soft grip material or padding on the handle ( 50 ). The power button ( 60 ) is preferably disposed within reach of the handle ( 50 ), and is preferably configured to slide to be activated/deactivated, and may be integrated with the dispose button ( 70 ).
[0018] The vacuum motor ( 80 ) of the present invention is housed within the canister ( 10 ), near the battery compartment ( 40 ) as shown in FIG. 1 . Power is supplied to the vacuum motor ( 80 ) via at least one wire ( 90 ) from the battery ( 30 ) when the power button ( 60 ) is activated by a user.
[0019] The vacuum motor ( 80 ) is ideally rated to provide enough suction to lift several kilograms from a variety of surfaces, including but not limited to lawns, pavement, wood flooring, carpeting, soil, and other similar environments. The canister ( 10 ), as well as the bag cartridge ( 220 ), are preferably equipped with at least one small vent ( 160 ) to provide an avenue for the suction intake of the vacuum motor ( 80 ) to prevent any loss of suction. The vent ( 160 ) may have a triangular shape. It should be noted that the vent ( 160 ) amounts to a gap, and may also be present on the bag cartridge ( 220 ). The canister ( 10 ) of the present invention is preferably water-proof, in order to ensure lasting durability of the present invention. The canister ( 10 ) is preferably rectangular or cylindrical in shape. It is envisioned that the present invention may come in a variety of sizes, however it is hoped that one size of canister ( 10 ) is sized appropriately to handle most jobs.
[0020] Additionally, the canister ( 10 ) of the present invention is equipped with a handle ( 50 ) to facilitate use and transport of the present invention. The handle ( 50 ) preferably includes a flash light ( 110 ) integrated into the body of the handle ( 50 ). Some embodiments of the present invention may position the flash light ( 110 ) as integrated into the canister ( 10 ) itself, in order to emit light from within the collection chute ( 100 ). Additionally, the canister ( 10 ) is preferably equipped with at least one exhaust port ( 105 ) in order to provide a route for the vacuumed air to escape when it is pumped through the present invention via the vacuum motor ( 80 ). The front of the canister ( 10 ) is preferably equipped with a collection chute ( 100 ) which is capable of swiveling, and is potentially flexible. The collection chute ( 100 ) has a rim ( 130 ) that is rough or equipped with at least one triangle-shaped gap, shown as vent ( 160 ), configured to provide an avenue through which air can travel. The vents ( 160 ) are preferably present on the bag cartridge ( 220 ) as well. The collection chute ( 100 ) and the rim ( 130 ) are configured to interface with a bag ( 170 ) of a bag cartridge ( 220 ), which preferably attaches to the rim ( 130 ).
[0021] It should be understood that, upon activation of the suction, air is pulled into the body of the present invention, causing the bag ( 170 ) of the bag cartridge ( 220 ) to expand into the collection chute ( 100 ), lining the interior of the collection chute ( 100 ). The force of suction is not diminished greatly by the bag ( 170 ), as the bag ( 170 ) is composed of a loose fibrous material which is partially porous, similar to a conventional internal vacuum cleaner bag. As such, the bag ( 170 ) is air-permeable. This allows air to escape while maintaining the debris within the bag. Therefore, the bag ( 170 ) is preferably equipped with a very fine, mesh-like fabric, making it permeable to air. Preferably only one bag ( 170 ) is present within each bag cartridge ( 220 ). A conventional air outlet preferably exists as an exhaust for the vacuum motor ( 80 ), and is preferably disposed on the body of the canister ( 10 ).
[0022] In the preferred embodiment of the present invention, prior to use of the present invention, the bag cartridge ( 220 ) is affixed to the rim ( 130 ) of the canister ( 10 ) near the tip of the collection chute ( 100 ). The bag ( 170 ) of the bag cartridge ( 220 ) that is deployed within the collection chute ( 100 ) is preferably equipped with a cardboard border ( 230 ) which is equipped with adhesive ( 180 ). Adhesive ( 180 ) is preferably present on the exterior of the cardboard boarder ( 230 ) in order to facilitate the sealing of the bag ( 170 ) after the waste is contained, and the boarder is mechanically turned up, similar to a shirt collar, orienting the elements of adhesive ( 180 ) such that they are opposite one another. After the application of suction to the solid pet waste, and the waste is brought into the bag ( 170 ), the cardboard border ( 230 ) is mechanically turned up, similar to a collar, such that the adhesive ( 180 ) is turned to face inwards. The border ( 230 ) is then compressed via an internal clamp ( 65 ) as shown in FIG. 6 , such that the adhesive effectively seals the bag ( 170 ) prior to disposal, preventing the escape of odor and waste. A mechanical release and seal button ( 95 ) is preferably present to facilitate the pushing of the border ( 230 ) off of the rim, allowing the entirety of the bag ( 170 ) and bag cartridge ( 230 ) to be drawn into the collection chute ( 100 ) via suction, at which point it is sealed via the internal clamp ( 65 ) shown in FIG. 6 . The internal clamp ( 65 ) is preferably composed of two separate clamp arms, which are each driven by a separate motor or an internal spring mechanism (shown as clamp mechanism ( 55 )).
[0023] During use of the present invention, the user, namely a pet owner or pet care provider, locates the pet waste, potentially with the use of the flashlight ( 90 ). Then, the user affixes a bag cartridge ( 220 ) to the rim ( 130 ) of the collection chute ( 100 ) of the canister ( 10 ) by opening the bag cartridge ( 220 ) such that the border ( 230 ) is in the form of a circle (namely, the shape of the rim ( 130 )), and slides the border ( 230 ) onto the rim ( 130 ), peels off the peel-away paper ( 190 ), and positions the collection chute ( 100 ) above the pet waste. Next, the user activates the device with the power button ( 60 ), activating the vacuum motor ( 80 ) of the present invention, which unfolds and draws in the bag ( 170 ) of the bag cartridge ( 220 ) into the interior of the collection chute ( 100 ) as shown in FIG. 1 . Alternate embodiments of the present invention may be automatically activated when the canister ( 10 ) is pressed against the floor or a surface containing the waste to be picked up. In such embodiments, automatic activation is preferably facilitated via a contact button integrated into the rim ( 130 ), which causes activation of the vacuum motor upon contact with the ground or floor.
[0024] The vacuum motor ( 80 ) creates suction which is directed to the pet waste via the collection chute ( 100 ), causing the pet waste to be suctioned into the bag ( 170 ). The bag ( 170 ) is preferably equipped with a paper-board or cardboard-based rim (referenced as border ( 230 )) equipped with the adhesive ( 180 ), which helps to ensure that bag ( 170 ) of the bag cartridge ( 220 ) may be easily sealed after use. Additionally, the border ( 230 ) serves to effectively mount the entirety of the bag cartridge ( 220 ) to the rim ( 130 ) of the present invention, as it is configured to slide over the rim ( 130 ) as shown in FIG. 1 . Peel-away paper ( 190 ) is preferably disposed atop the adhesive, which is preferably peeled off of the bag cartridge ( 230 ) after the bag cartridge ( 220 ) is installed on the rim ( 130 ) of the collection chute ( 100 ) by the user. Instantiations of the peel-away paper ( 190 ) covering the adhesive ( 180 ) of the present invention are preferably delineated with perforations ( 200 ) to facilitate removal of the peel-away paper ( 190 ), as shown in FIG. 2 .
[0025] The bag ( 170 ) contained within each bag cartridge ( 220 ) is preferably uni-directionally porous, similar to conventional vacuum bags. The user then preferably locates a garbage receptacle, such as a public trash can, or a trash can at the home of the user. With the collection chute ( 100 ) of the device placed over the garbage receptacle, the user activates the dispose button ( 70 ), releasing the sealed (via adhesive ( 180 )) bag ( 170 ) containing the pet waste from the collection chute ( 100 ) and into the garbage receptacle. In some embodiments of the present invention, a door ( 150 ) is present across the rim ( 130 ) of the collection chute ( 100 ). The door ( 150 ) is preferably segmented into triangular segments, which form the shape of the collection chute ( 100 ) when closed. The door ( 150 ) preferably opens inwards as shown in FIG. 5 , into the collection chute, and remains open until the bag ( 170 ) containing the pet waste has been drawn into the collection chute ( 100 ) for disposal.
[0026] Some embodiments of the present invention depict a door ( 150 ) of the canister ( 10 ) that pops closed, then open during the disposal process, after activation of the dispose button ( 70 ) by the user, facilitating an automatic sealing of the bag ( 170 ) via the adhesive ( 180 ) after the border ( 230 ) is flipped up, away from the collection chute ( 100 ), or is otherwise detached from the rim ( 130 ). In some of such embodiments, the adhesive ( 180 ) may be disposed on the interior of the cardboard border ( 230 ), rather than as shown in FIG. 2 , which removes the need for the cardboard border ( 230 ) to be flipped in order for the bag ( 170 ) to seal via the adhesive ( 180 ). It is envisioned that, in no embodiment of the present invention is the user required to touch any portion of the invention other than the dispose button ( 70 ) and power button ( 60 ), ensuring that the user remains free of waste contaminants during and after use of the present invention.
[0027] In other embodiments of the present invention, the rim ( 130 ) itself is configured to twist about the collection chute ( 100 ), helping to free the border ( 230 ) from the rim ( 130 ) during disposal, and facilitate the sealing of the bag ( 170 ) via the adhesive ( 180 ) on the border ( 230 ).
[0028] The canister ( 10 ) may be equipped with a door disposed at or near the rim ( 130 ) of the collection chute ( 100 ) in some embodiments of the present invention, wherein the door ( 150 ) automatically opens when the power button ( 60 ) is activated, and seals shut when the power button ( 60 ) is deactivated. Such a door ( 150 ) would preferably also open upon activation of the dispose button ( 70 ), and seal again after the bag ( 170 ) has been sealed, ejected, and disposed of within a garbage receptacle.
[0029] Some embodiments of the present invention are configured with an external charging cradle to facilitate the charging of the battery ( 30 ) when the present invention is not in use. An external charging cradle is envisioned to be affixed to a wall or placed on a table near a door, potentially with the leash of the pet, in order to facilitate the process of ‘walking the dog.’ Additionally, some embodiments may include variations on the type of switch employed as a power button ( 60 ) and dispose button ( 70 ). For example, a neutral, off position of a slider-type switch may be employed as seen in FIG. 1 , displaying an off switch ( 120 ). Additionally, in some embodiments of the present invention, a button may be present that reverses the flow of the suction to further facilitate ejection of the bag ( 170 ) during disposal. Similarly, the vacuum motor ( 80 ) may be configured to reverse upon activation of the dispose button ( 70 ).
[0030] Other alternate embodiments of the present invention are envisioned to have a narrow canister ( 10 ) and rim ( 130 ), while having a wider collection chute ( 100 ) in order to facilitate a more direct placement via suction of the waste into the bag ( 170 ). Such embodiments are preferably equipped with a door. Additionally, all embodiments of the present invention are preferably equipped with at least one pocket or compartment ( 300 ) disposed on the outside of the collection chute ( 100 ) in order to facilitate the storage of additional bag cartridges ( 220 ) in their folded state, as shown in FIG. 3 and FIG. 4 . Each compartment ( 300 ) is preferably configured to hold at least one bag cartridge ( 220 ) for later use.
[0031] One alternate embodiment of the present invention employs industrial-strength suction, which facilitates the automatic flipping of the cardboard border ( 230 ) off of the rim ( 130 ) via suction alone. In such embodiments, the suction first draws the bag ( 170 ) into the collection chute ( 100 ), then draws the waste into the bag ( 170 ). With the suction still activated, the user releases a cartridge release button ( 75 ), which releases tension (which is provided via tensioners ( 85 ) that apply a spring-like outward force to the border ( 230 ) of the bag cartridge ( 220 ) to hold it in position, shown in FIG. 5 ) from the cardboard border ( 230 ), allowing the suction to draw the entirety of the border ( 230 ), bag ( 170 ) and waste into the collection chute ( 100 ) without the need for human contact. The force of this movement causes the adhesive ( 180 ) to adhere to the cardboard border ( 230 ), sealing the bag ( 170 ) closed. The door ( 150 ) then closes over the collection chute ( 100 ) (as the bag ( 170 ) is no longer affixed to the rim ( 130 )), and the suction may be deactivated. This allows for the user to locate a trash can with the sealed bag ( 170 ) encased within the collection chute ( 100 ) behind the door ( 150 ). Upon locating a trash can, the user activates the dispose button ( 70 ), which opens the door ( 150 ), and allows the exit of the bag ( 170 ) containing the waste into the trash can without the user touching the bag ( 170 ) or trash can. Some embodiments may activate a reverse suction (blower) upon activation of the dispose button ( 70 ) to facilitate removal of the bag ( 170 ) from the collection chute ( 100 ) into the trash can without the need for human touch or intervention. It such embodiments, it is envisioned that the battery ( 30 ) may require recharging between uses.
[0032] Another alternate embodiment facilitates sealing of the bag ( 170 ) via a rotating mechanism disposed at or within the rim ( 130 ), which facilitates a twisting of the bag within the collection chute ( 100 ) shortly after the application of suction to the waste. Such embodiments employing this rotating mechanism preferably employ the cardboard border ( 230 ), which serves as a mount against which the rotation of the device may relatively rotate. The application of suction causes the rear or bottom of the bag ( 170 ) to remain in a relatively fixed position within the collection chute ( 100 ), and facilitates the sealing of the bag ( 170 ) via twisting the cardboard border ( 230 ) affixed to the bag ( 170 ) of the bag cartridge ( 220 ). Such embodiments preferably also employ a reverse suction (blower) to facilitate the easy removal of the sealed bag ( 170 ) from within the collection chute ( 100 upon location of a trash can.
[0033] Having illustrated the present invention, it should be understood that various adjustments and versions might be implemented without venturing away from the essence of the present invention. Further, it should be understood that the present invention is not solely limited to the invention as described in the embodiments above, but further comprises any and all embodiments within the scope of this application. Similarly, it should be understood that the depiction of the present invention in FIG. 1 embodies an example of a configuration of the essential elements of the present invention.
[0034] 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 present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiment was chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. | A solid pet waste vacuum and bagging device is described. The device is equipped with a canister, collection chute, vacuum motor, and a bag cartridge. The device eliminates the need for an individual to come into any contact with pet waste, including the temperature and the smell conventionally known to emanate from pet waste. The device employs the vacuum motor to collect pet waste within the bag via the collection chute. The collection chute is lined with a plastic bag, which is sealed and released from the collection chute within the canister upon activation of a dispose button by the user. The device is powered by rechargeable batteries, and may be equipped with a charging cradle to maintain a fully charged battery. | 4 |
This is a Divisional of application Ser. No. 08/235,849, filed Apr. 29, 1994.
TECHNICAL FIELD OF THE INVENTION
This invention relates in general to integrated circuit devices and more particularly to an assembly process and a structure for packaging an integrated circuit.
BACKGROUND OF THE INVENTION
Following the fabrication of a semiconductor integrated circuit, the completed device is be attached to a lead frame so as to provide connections to external components through, for example, a printed circuit board (PCB). Moreover, the integrated circuit device is encapsulated in order to protect it from environmental factors as well as to standardize its physical dimensions for the purpose of interfacing with other devices at the component level.
As is well known in the art, increasing circuit complexities, device miniaturization and additional circuit board space limitations have called for smaller and smaller package volumes. It is, therefore, easily understood why it is desirable for the package volume to be as close in size to the encapsulated circuit die as possible.
One of the major problems resulting from conventional packaging processes is the occurrence of voids in the encapsulating material itself. Voids can refer both to holes in the hardened plastic package or to an incomplete package. These voids are believed to occur as a result of a lack of fluidization of the encapsulating material, or by a chase or runner jamming mechanism which may occur when the encapsulating material starts to solidify before it reaches the mold cavity. As additional encapsulating material is forced down the runners, the partially solidified material enters the cavity but fails to completely fill it in. This results in what is sometimes referred to in the industry as the “incomplete fill” problem. As is known in the art, the incomplete fill problem is exacerbated as package thickness is decreased.
Another disadvantage of conventional packaging technologies occurs when constructing multi-chip modules (MCMs). In this case there is often an inability to test each individual component for electrical function prior to the time that the component is encapsulated in the MCM.
SUMMARY OF THE INVENTION
From the foregoing, it may be appreciated that a need has arisen for a semiconductor packaging assembly and method whereby a very thin form factor can be achieved. A need has also arisen for a method and assembly which eliminate the above-described incomplete fill problem. Additionally, a need has arisen for a packaging method providing the ability to test circuit functionality prior to incorporation into a multichip module (MCM) so as to eliminate the possibility of including a faulty chip in an MCM.
In accordance with the present invention, a method and apparatus is provided for fabricating small form factor semiconductor chips having high temperature resistance, good humidity and chemical resistance and good dielectric properties. The semiconductor chip of the present invention includes a lead frame attached to an integrated circuit die by a lead-on-chip (LOC) method. Wire bonds are employed to connect the integrated circuit to conduction leads on the lead frame. After the wire bonding process, the surface of the wire bonded integrated circuit is encapsulated with a layer of resin using either a direct dispensing method or by a screen printing method. The encapsulated integrated circuit is then cured and functionally tested.
The present invention provides various technical advantages over conventional semiconductor chips. For example, one technical advantage is the ability to encapsulate integrated circuits within very thin packages. Another technical advantage is the chip's ability to resist high temperatures, humid environments and contact with various chemicals. Other technical advantages will be readily apparent to one skilled in the art from the following figures, descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, in which:
FIG. 1 illustrates an overview of the encapsulate resin LOC process according to one embodiment of the invention;
FIG. 2 is an exploded view of the resin LOC package according to one embodiment of the invention;
FIG. 3 is an isometric view of the resin LOC package according to one embodiment of the invention;
FIG. 4 is a side view of the resin LOC package according to one embodiment of the invention;
FIG. 5 illustrates one possible embodiment of an encapsulation method according to the invention;
FIG. 6 illustrates a second possible embodiment of an encapsulation method according to the invention;
FIGS. 7A-C illustrate side views of the resin LOC package in three possible configurations.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagrammatic illustration of the manufacturing processing steps for constructing the resin LOC package in accordance with one embodiment of this invention. For purposes of this discussion, a broad overview of this process will be given in connection with FIG. 1. A discussion of the detail of each broad step and the material involved will follow in conjunction with subsequent figures. In one embodiment of this invention, multiple integrated circuits are packaged concurrently and later separated or singulated. It will be understood by one skilled in the art that the below-described process could similarly be performed on individual integrated circuits without deviating from the invention herein.
Initially, lead frame 10 is combined with adhesive tape 20 . Adhesive tape 20 may be a double-sided tape which is placed in contact with the bottom of lead frame 10 on one side and in contact with the integrated circuit die 30 on the other side. The integrated circuit die 30 may thus be fastened to the lead frame 10 using a lead-on-chip (LOC) mounting method.
The combination of the lead frame 10 , adhesive tape 20 and integrated circuit die 30 is next processed so as to form wire bonds 40 connecting the integrated circuit to conduction leads on the lead frame 10 . After the wire bonding step is completed, the surface of the wire bonded lead frame and integrated circuit combination is encapsulated with a resin compound 50 . Resin compound 50 may be any resin known in the art which provides environmental and mechanical protection for the chip. The encapsulated device may then be cured in an oven at a specified temperature profile. Each of the cured chips are then singulated and the leads are trimmed and formed. Electrical testing may occur after encapsulation subsequent to singulation.
FIG. 2 illustrates an exploded view of the structure of the encapsulate resin LOC package. It can be seen that integrated circuit die 30 may be designed such that some or all of the contact pads 35 lie in linear fashion in the center of integrated circuit die 30 . Adhesive tape 20 may then consist of two thin rectangular strips each placed on alternate sides of contact pads 35 . As will be apparent to one of ordinary skill in the art, contact pads 35 could, for example, alternately be placed on the perimeter of integrated circuit die 30 . In this case adhesive tape 20 could be arranged in any manner so long as it does not interfere with the access to contact pads 35 . In the event that contact pads 35 lie in the center of integrated circuit die 30 , as described above, lead frame 10 may be designed so as to consist of two separate groupings of leads which are connected during the packaging process but disengaged at the time of singulation.
FIG. 3 is an isometric view of the resin LOC package according to one embodiment of the invention. In this embodiment, contact pads 35 run linearly down the center of integrated circuit die 30 . Wire bonds 40 attach contact pads 35 to one or more selected leads 75 located on lead frame 10 . The wire bonds 40 may be any thin, durable, conductive metal, such as gold wires having a diameter of 1.2 Mil, for example. Lead frame 10 may include an elongated strip 55 of metal connecting one or more leads 75 . Such a strip 55 may be employed as a ground or supply voltage conductor which is connected, via wire bond 40 , to the proper contact pad(s) 35 located on integrated circuit die 30 .
Adhesive tape 20 is located directly on the surface of integrated circuit die 30 on one side. The other side of adhesive tape 20 may be attached to lead frame 10 in a variety of ways. For example, adhesive tape 20 may contact lead frame 10 along the length of elongated strip 55 as shown in FIG. 3 . Adhesive tape 20 may further contact the interior end of leads 75 as also illustrated in FIG. 3 . The adhesive tape 20 is attached on both sides during the LOC mounting process at elevated temperature and pressure.
The metal lead frame 10 may be Alloy 42 pre-plated with silver although a variety of other configurations are possible as is known in the art. The resin 50 which is applied subsequent to the wire bonding step may be comprised of any of a variety of materials such as epoxy, silicone and polyimide.
FIG. 4 is a side view of the resin LOC package. The underlying integrated circuit die 30 can be seen to be covered at two locations with adhesive tape 20 . It is also possible to employ, for example, a single strip of adhesive tape 20 to attach an integral lead frame 10 at a single point. Also shown are wire bonds 40 connecting contact pads 35 to leads 75 . Elongated strips 55 which may or may not be present in a device according to this invention are also shown in FIG. 4 .
FIG. 5 illustrates one possible embodiment of an encapsulation method according to this invention. In this resin dispensing method, a syringe-type liquid dispensing system 95 is loaded with resin material 50 which may be selectively dispensed either by an operator or through automated controls. This system provides the ability to accurately position the dispensing nozzle as well as the ability to control the volume of resin material 50 dispensed at any one time. The dispensed resin pattern can be programmed to be centered at a particular location, to be a certain depth and to extend laterally to particular dimensions depending upon chip size, lead frame configuration and the length and curvature of the wire bond 40 . The viscosity of the encapsulant will affect the extent to which the die surface is wetted. The surface to be coated consists of leadframe 10 , wire bonds 40 and die 30 , and is thus very irregular. In the case of FIG. 5, a lower viscosity encapsulant would be used to achieve proper rheology due to the irregularity of the surface shape.
Resin material 50 may, for example, be deposited at room temperature (25 degrees centigrade) and curing may be accomplished in a range from 100 degrees centigrade to 200 degrees centigrade.
FIG. 6 illustrates another possible method of encapsulation according to this invention. In this screen printing method, after the die 30 is attached to the lead frame 10 and wire bonding is completed, a stencil or metal printing mask 15 with the desired top package shape is placed on top of the lead frame 10 . Resin material 50 is then placed so it generally blankets the non-void area of metal printing mask 15 . Following this step, one or more wipers 25 are placed in contact with the resin material 50 so that the wipers can relocate the resin material 50 into the void areas of the printing mask 15 . In this method, a very high viscosity resin material 50 is used because the thickness of the resin 50 is controlled by the thickness of the stencil and thus the depth of the voids positioned for encapsulant deposition.
As will be apparent to one of ordinary skill in the art, the methods according to this invention eliminate the incomplete fill problem caused by prior art methods. Because a conventional mold is unnecessary, very thin packages may be fabricated which do not suffer from cracking and other problems associated with a situation where small voids remain in the encapsulant material.
FIGS. 7 a - 7 c illustrate some possible applications for semiconductor chips packaged according to the current invention. In FIG. 7 a , a stack chip 37 (MCM) is shown wherein two encapsulated chips are placed back to back. The encapsulated chips are commonly further encapsulated in mold 97 using a transfer molding process as is common in the industry. Each one of the leads 75 on the semiconductor chips 47 are joined at a common lead 35 thus resulting in a common lead 35 for each lead 75 present on each of the semiconductor chips 47 . It is also possible to employ two functionally different semiconductor chips in the same mold. Particular leads 75 may then be selected to be joined with a common lead 35 to achieve a desired functional result.
It is to be understood that by using this method of constructing the MCM, it is possible to ensure proper chip functionality prior to encapsulation in the MCM. This is especially true for memory chips which typically undergo a series of functional electrical tests.
In either MCM embodiment, common leads 35 of stack chip 37 may be directly interfaced with a printed circuit board 67 . This is illustrated in FIG. 7 c . FIG. 7 b illustrates a single semiconductor chip 47 according to one embodiment of this invention located on printed circuit board 67 .
Thus, it is apparent that there has been provided, in accordance with the present invention, a method and apparatus for packaging an integrated circuit that satisfies the advantages set forth above. Although particular embodiments have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope or spirit of this invention. | A method and apparatus for fabricating small form factor semiconductor chips having high temperature resistance, good humidity and chemical resistance and good dielectric properties. The semiconductor chip includes a lead frame ( 10 ) attached to an integrated circuit die ( 30 ) by a lead-on-chip (LOC) method. Wire bonds ( 40 ) are employed to connect the integrated circuit die ( 30 ) to conduction leads ( 75 ) on the lead frame ( 10 ). After the wire bonding process, the surface of the wire bonded integrated circuit is encapsulated with a layer of resin ( 50 ) using either a direct dispensing method or by a screen printing method. The encapsulated integrated circuit may then be cured and functionally tested. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to containers with non-detach tab and more particularly pertains to a new container end closure for facilitating the opening of a pressurized container.
2. Description of the Prior Art
The use of container end closures is known in the prior art. More specifically, container end closures heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art includes U.S. Pat. No. 4,276,993; U.S. Pat. No. 4,266,688; U.S. Pat. No. 5,749,488; U.S. Pat. No. 4,015,744; U.S. Pat. No. 3,301,434; and U.S. Pat. No. Des. 263,803.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new container end closure. The inventive device includes a non-detachable tab having a bulbous end proximate a frangible section of the end closure and a recess in the end closure proximate an opposite end of the tab.
In these respects, the container end closure according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of facilitating the opening of a pressurized container.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of container end closures now present in the prior art, the present invention provides a new container end closure construction wherein the same can be utilized for facilitating the opening of a pressurized container.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new container end closure apparatus and method which has many of the advantages of the container end closures mentioned heretofore and many novel features that result in a new container end closure which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art container end closures, either alone or in any combination thereof.
To attain this, the present invention generally comprises a non-detachable tab having a bulbous end proximate a frangible section of the end closure and a recess in the end closure proximate an opposite end of the tab.
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.
It is therefore an object of the present invention to provide a new container end closure apparatus and method which has many of the advantages of the container end closures mentioned heretofore and many novel features that result in a new container end closure which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art container end closures, either alone or in any combination thereof.
It is another object of the present invention to provide a new container end closure that may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new container end closure that is of a durable and reliable construction.
An even further object of the present invention is to provide a new container end closure which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such container end closure economically available to the buying public.
Still yet another object of the present invention is to provide a new container end closure which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new container end closure for facilitating the opening of a pressurized container.
Yet another object of the present invention is to provide a new container end closure which includes a non-detachable tab having a bulbous end proximate a frangible section of the end closure and a recess in the end closure proximate an opposite end of the tab.
Still yet another object of the present invention is to provide a new container end closure that is easily opened by insertion of a finger into the recessed portion of the end closure.
Even still another object of the present invention is to provide a new container end closure that permits increased leverage by a pivoting tab on a frangible section of the end closure by permitting insertion of a finger beneath one end of the tab.
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 made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a perspective view of a new container end closure according to the present invention.
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a perspective view of an alternate embodiment of the present invention.
FIG. 4 is a cross-sectional view taken along line 2--2 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 through 4 thereof, a new container end closure embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
As best illustrated in FIGS. 1 through 4, the container end closure 10 generally comprises an end wall 12 of sheet material including an outer perimeter 14 and a center portion 20. In a first embodiment, the outer perimeter 14 is designed for engagement to side walls 18 of the can 11.
To facilitate attachment of the end closure 10 to the side walls 18, an inner channel 19 is positioned between the outer perimeter 14 and the center portion 20.
The center portion 20 includes a substantially planar upper surface 22, an opening panel 24 at least partially circumscribed by a scoreline 25, and a generally rounded recess 30 positioned opposite the opening panel 24.
A tab 40 is coupled to the center portion 20 of the end wall 12 at a medial portion 42 of the tab 40. The tab 40 defines a longitudinally rigid lever with a bulbous first end 44 positioned proximate and extending over the opening panel 24 and a second end 46 positioned proximate and extending over the recess 30.
The recess is designed to permit comfortable insertion of a finger into the recess to lift the second end 46 of the tab 40. The bulbous end 44 of the tab 40 is designed for bearing against the opening panel 25 when the second end 46 is lifted. The breakage of the scoreline 25 is initiated by sufficient lifting of the second end 46 whereby the opening panel 24 is urged away from the planar surface 22 to provide an opening 27 in the can 11.
The recess 30 has a substantially vertical portion 32 proximate the inner channel 19 and opposite the opening panel 24. The recess 30 also has a curved bottom portion 34 such that the recess 30 tapers upwardly as it approaches a center of the center portion 20.
The tab 40 is most preferably hour-glass shaped to distribute a substantial portion of a mass of the tab 40 towards the first and second ends 44 and 46 for facilitating opening of the can 11 by breaking the scoreline 25. The bulbous end 44 of the tab 40 also preferably includes a solid construction for increasing a portion of the mass of the tab 40 positioned over the opening panel 24.
The tab 40 has a generally C-shaped slit 48 therein to form a tongue 50 in the medial portion 42 of the tab 40. An open end 49 of the C-shaped slit is oriented to face away from the bulbous end 44 such that the tongue 50 points generally towards the bulbous end 44. A rivet 52 is inserted through the tongue 50 and the center portion 20 of the end wall 12 such that the tongue 50 is coupled to the end wall 12. The rivet 52 includes a flattened upper portion 54 abutting the tongue 50 such that the tongue 50 is prevented from decoupling from the end wall 12 when the second end 46 of the tab 40 is lifted.
In an alternate embodiment, the outer perimeter 14A of the end wall 12A is of solid construction extending substantially orthogonally from the planar upper surface 22A of the center portion 20A to integrally form side walls 18A of the can 11A.
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. | A container end closure for facilitating the opening of a pressurized container. The container end closure includes a non-detachable tab having a bulbous end proximate a frangible section of the end closure and a recess in the end closure proximate an opposite end of the tab. | 1 |
This application claims the benefit of U.S. Provisional Application No. 60/099,317, filed Sep. 4, 1998.
BACKGROUND OF THE INVENTION
The present invention relates generally to a collet chuck assembly for holding a tool or workpiece on a spindle of a turning machine and particularly to a collet chuck that can be changed quickly and easily.
Collets are sleeves or collars used in various machine tools such as lathes for clamping or gripping workpieces or tools. Collets include a plurality of circumferentially-spaced, workpiece-gripping segments and conical surfaces or cams, which, when the collet is moved axially, interact with corresponding, opposing surfaces or cams on a mounting fixture or on the spindle. This interaction causes the workpiece-gripping segments of the collet to contract or expand to grasp or release a workpiece or tool, depending on the direction of movement. Collet chucks have commonly been used in machine tools in place of other types of chucks. Collet chucks are typically more accurate and have a greater gripping characteristic than a typical jaw chuck, for example. An advantage of collets is that they continue to grasp the workpiece or tool even at high rotational speeds when jaw chucks would have a tendency to loosen their grip due to centrifugal force.
One problem encountered with collet chucks is that slight variations in the diameter of the workpiece or stock could cause the collet to position the workpiece differently. When and where a collet will grasp a work piece depends on the difference in diameter between the open collet and the diameter of the workpiece. Precise workpiece diameter is therefore required if the workpiece is to be positioned precisely and consistently in machining operations such as facing, side finishing or cutting to precise lengths.
Another problem encountered with conventional collet assemblies is that collet cannot be easily and quickly removed from the spindle. Accordingly, changing collets can be time consuming.
For example U.S. Pat. Nos. 5,096,213 and 5,330,224, the respective disclosures of which are hereby incorporated by reference, disclose collet chucks in which a collet body includes an annular groove and hook portion on a rear end of the body which engages an annular flange portion of a spindle of the turning machine or a drawbar adapter of the collet assembly. A collet is installed by engaging the hook portion of the collet to the flange portion of the spindle or adapter, a special tool, such as those disclosed in U.S. Pat. Nos. 4,589,938 or 5,087,059, the respective disclosures of which are hereby incorporated by reference, is needed to compress the rear portions of the collet segments a sufficient distance radially inwardly so that the hook portion of the collet clears the annular flange portion. Similarly, to remove the collet from the turning machine, the tool must again be used to compress the rear portions of the segments so that the hook portions clear the flange portions so that the collet can be disengaged.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the forgoing disadvantages which accompany prior art collets. This object is achieved by a collet chuck assembly for holding a tool or workpiece on a spindle of a turning machine constructed in accordance with principles of the present invention. The collet chuck assembly comprises a mount, a collet assembly, and a cap.
The mount has a rear end adapted to be connected to the spindle and cap engaging structure. The collet assembly includes a collet structure for holding a tool or workpiece and operatively interacting cam surfaces. The collet assembly permits relative movement between the cam surfaces, whereby relative movement between the cam surfaces in one direction closes the collet structure to hold the tool or workpiece and relative movement between the cam surfaces in another direction opens the collet structure to release the tool or workpiece. The cap is secured to the mount and engages a front end of the collet structure to maintain the front end at a fixed axial position with respect to the cap and the mount during the relative movement between the cam surfaces of the collet assembly. The cap includes mount engaging structure adapted to coact with the cap engaging structure of the mount to prevent relative axial displacement between the cap and the mount when the cap is in a cap-locked position with respect to the mount. The cap is placed in the cap-locked position by coupling the cap to the mount with the cap-engaging structure of the mount and the mount-engaging structure of the cap disengaged from one another and then rotating the cap less than one revolution with respect to the mount to interengage the cap-engaging structure of the mount with the mount-engaging structure of the cap.
Accordingly, the collet structure does not move axially with respect to the assembly so that tools and workpieces can be gripped and positioned consistently. Furthermore, installing a collet is easily accomplished by merely inserting a collet structure into the collet assembly, engaging a cap over the collet structure onto the mount, and rotating the cap into the cap-locked position.
Other objects, features, and characteristics of the present invention, as well as the methods of operation of the invention and the function and interrelation of the elements of structure, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this disclosure, wherein like reference numerals designate corresponding parts in the various figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the collet chuck assembly according to the present invention;
FIG. 2 is an exploded cross-sectional view of the collet chuck assembly;
FIGS. 3A, 3 B, and 3 C are a side elevation, bottom plan view, and top plan view, respectively, of a mount of the collet chuck a assembly;
FIG. 3D is a side elevation of the mount rotated 90 degrees with respect to the side elevation of FIG. 3A;
FIG. 4 is a side elevation of a rotation tool used in conjunction with the collet chuck assembly;
FIGS. 5A, 5 B, and 5 C are a side cross-sectional view, a bottom plan view, and a top plan view, respectively, of a quick-change cap of the collet chuck assembly;
FIG. 5D is an enlarged view of the quick-change cap within the circle “D” in FIG. 5A;
FIG. 5E is an enlarged view of the portion of the quick-change cap within the circle “E” in FIG. 5B;
FIGS. 6A, 6 B, and 6 C are a top plan view, right side elevation, and left side elevation, respectively, of a pin-actuating cam of the collet chuck assembly;
FIG. 7 is a cross-sectional view of an alternative collet used in conjunction with the collet chuck assembly;
FIG. 8 is a side elevation of a solid stop assembly optionally used in conjunction with the collet chuck assembly; and
FIG. 9 is a cross-sectional view of a rear guide bushing optionally used in conjunction with the collet chuck assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For convenience in the following description, various directional or other spatial references are made with regard to references to the drawings. It is understood, however, that such references, including without limitation, front, back, forward, rearward, upper, lower, top, bottom, left, right, lateral, or longitudinal, are made for convenience only and should not be construed to be limiting on the invention described herein.
A collet chuck assembly according to the present invention for holding a tool or workpiece is indicated generally by reference number 30 in FIGS. 1 and 2. The collet chuck assembly 30 is attached to a spindle 10 and draw bar 12 of a machine, for example a lathe. The collet chuck assembly 30 generally comprises a mount 60 , a collet assembly which includes a collet sleeve 100 , a collet 80 , and a collet spring 36 , and a quick-change cap 40 .
An O-ring 16 may be disposed between the draw bar 12 and spindle 10 to prevent lubricants from escaping between the draw bar 12 and spindle 10 and to prevent debris from entering the draw bar 12 and spindle 10 .
As shown in FIGS. 1 and 2 and FIGS. 3A-3D, the mount 60 includes equally spaced, counterboard axial through-holes 62 formed about the outer periphery of the mount 60 . Mount 60 also includes an inner tapered surface 64 shown at the left side thereof in the figures, which, for convenience, will be referred to as the rear side. Surface 64 cooperates with outer tapered surface 20 of the machine spindle 10 to appropriately position the mount 60 with respect to the spindle 10 , as described, for example, in U.S. Pat. No. 5,096,213, the disclosure of which is hereby incorporated by reference. Mount 60 also includes a pair of diametrically opposed blind holes 76 formed in the rear end face 77 which cooperate with a pair of mating projections (not shown) extending from the end of the spindle 10 as disclosed in the previously mentioned U.S. Pat. 5,096,213. Fasteners 63 (e.g., socket head cap screws) extend through the counterboard through-holes 62 into threaded blind apertures 18 formed in the spindle 10 to secure the mount 60 to the spindle 10 .
As best shown in FIG. 2, mount 60 further includes a cam aperture 65 extending radially to an outer surface of the mount 60 . An axial aperture 66 extends from rear end-face 77 of the mount 60 to the cam aperture 65 . A second axial aperture 67 extends from a front annular shoulder 73 of the mount 60 opposite rear end-face 77 to a position beyond the cam aperture 65 . Axial apertures 66 and 67 are radially offset and radially aligned with one another in a parallel relation. A tangential aperture 68 (see FIG. 3C) extends from a side surface of the mount 60 to the axial aperture 67 . As shown in FIG. 3D, a slot 71 extends radially from the cam aperture 65 and communicates with an arcuate slot 69 formed below the outer surface of the mount 60 .
To compensate for the radial imbalance caused by the removal of material for apertures 65 , 66 , 67 , and 68 on one side of the mount 60 , balance holes 61 are formed on a diametrically opposite side of the mount 60 . In the illustrated embodiment, two balance holes 61 are formed, one on either side of one of the through-holes 62 .
A cylindrical extension 70 extends from one end of the mount 60 . Extension 70 has a diameter generally less than the remainder of the mount 60 and therefore defines the annular shoulder 73 at the base of the cylindrical extension 70 . Cap-engaging structure, such as radial flanges 72 , extend from the axial end of the cylindrical extension 70 . In the illustrated embodiment, three such flanges 72 extend from the extension 70 . In the preferred embodiment, flanges 72 are not equally spaced about the perimeter of the cylindrical extension 70 . The radial flanges 72 define a peripheral channel 81 (see FIG. 3A) extending about the base of the cylindrical extension 70 . A dowel pin 74 extends radially from the outer surface of the cylindrical extension 70 at a generally central portion of the peripheral channel 81 adjacent to an edge of one of the radial flanges 72 .
Mount 60 is preferably machined from 8620-C steel and is hardened to Rockwell C hardness of about 61 .
As shown in FIGS. 1 and 2, collet sleeve 100 is disposed radially inwardly of the mount 60 within the assembly 30 . Collet sleeve 100 includes an enlarged portion 110 (at the right hand side thereof in the figure), intermediate portion 112 , and narrow end portion 114 . An interior annular shoulder 116 is defined between the intermediate portion 112 and narrow end portion 114 . External threads 106 are formed on the narrow end portion 114 , and threads 106 engage with internal threads 14 formed in the draw bar 12 (see FIG. 1) to secure the sleeve 100 to the draw bar 12 , thereby coupling the assembly 30 to the draw bar 12 .
Collet sleeve 100 includes an inner tapered, frusto-conical cam surface 102 formed on the interior of the enlarged head portion 110 . Axially extending slots 108 are formed about the outer peripheral surface of the enlarged head portion 110 . Although only one such slot 108 is shown in FIGS. 1 and 2, in the preferred embodiment, three equally spaced slots are provided. One of the slots 108 is engaged by a key screw 79 extending through a radial key hole 75 formed in the mount 60 (see FIG. 3 C). The key screw 79 engaging one of the slots 108 prevents relative rotation between the collet sleeve 100 and the mount 60 .
Sleeve 100 is preferably machined from 8620-C steel, and the entire sleeve is initially hardened to a Rockwell “a” hardness of about 81.8-82.8 (approximately 61-63 on the Rockwell C scale). Subsequently, a rear portion of the sleeve 100 extending from end portion 114 to a location just forward (i.e., to the right in the drawings) of annular shoulder 116 is drawn down to a Rockwell “a” hardness of about 70.4-73.1 (approximately 42-45 on the Rockwell C scale).
As shown in FIGS. 1 and 2, the collet 80 is disposed inside the collet sleeve 100 . A collet spring 36 is disposed between an annular end-face 96 of the collet 80 and the interior annular shoulder 116 of the collet sleeve 100 . Collet spring 36 is preferably a rectangular wire spring. Collet 80 includes an outer tapered cam surface 82 and a plurality of collet segments 89 separated by slots 90 . In the preferred embodiment, three equally spaced collet segments 89 are provided, although one skilled in the art will readily appreciate that more than three segments can be employed. Holes 84 extending radially inwardly from the outwardly tapered surface 82 are drilled into each of the slots 90 . The holes 84 receive an elastomeric sealing member (not shown) inserted therein to prevent debris from entering into the machine spindle 10 through the collet slots 90 .
The segments 89 contract radially when the collet 80 is closed and expand radially when the collet 80 is opened in response to the camming interaction of the tapered cam surface 82 of the collet 80 and the tapered cam surface 102 of the collet sleeve 100 during relative axial movement of the cam surfaces 82 , 102 with respect to each other. A slot relief opening 92 is preferably provided at the axial end of each of the slots 90 to facilitate the radial expansion and contraction of the segments 89 .
Collet 80 is preferably machined from 2317 steel, and the entire collet is hardened to a Rockwell C hardness of 61-63. Subsequently, a portion of the collet 80 generally rearwardly (i.e. to the left in the drawings) of the cam surface 82 is drawn down to a Rockwell C hardness of 42-45. The generally softer rear end of the collet 80 facilitates radial contraction of the collet segments 89 during gripping.
An axially extending key-way slot 85 is formed in the outer surface of the collet 80 adjacent the annular rear end-face 96 . Key way slot 85 receives a dowel pin 105 extending through a radial opening 104 formed in the collet sleeve 100 to prevent relative rotation between the collet 80 and the collet sleeve 100 . Pin 105 is preferably formed from 8620-C steel hardened to a Rockwell C hardness of about 35. The collet 80 may include drilled holes 86 formed in the annular front end-face 94 . Although only a single hole 86 is shown in FIGS. 1 and 2, the preferred embodiment includes three equally-spaced holes formed in the annular front end-face 94 . Holes 86 accommodate a collet pad clamp (not shown) for a master collet, such as collet 80 shown in FIGS. 1 and 2.
An annular shoulder 98 extends about the periphery of the collet 80 . Shoulder 98 is axially displaced from the annular front end face 94 and defines an axial boundary of the outer tapered cam surface 82 . Shoulder 98 is preferably beveled at a slight angle of approximately 10 degrees.
As shown in FIGS. 1, 2 , and 5 A- 5 D, the quick-change cap 40 includes a radially extending portion 42 and an axially extending portion 44 . The outer surface of the axially extending portion 44 may be knurled so as to facilitate the gripping thereof. A circular opening S 0 is centrally formed in the radial portion 42 of the quick-change cap 40 .
As shown in FIG. 5B, the quick-change cap 40 includes mount-engaging structure, such as lugs 46 , extending radially inwardly from the axial end of the axially extending portion 44 of the quick-change cap 40 . In the preferred embodiment, three unequally-spaced lugs 46 are provided. The lugs 46 define cut-out areas 47 between adjacent lugs 46 . As shown in FIGS. 5A and 5D, the radially extending portion 42 of the cap 40 defines an annular inner face 54 extending about the periphery of the opening 50 . Annular inner face 54 includes a beveled surface 52 extending about the edge of the opening 50 . Beveled surface 52 is preferably formed at an angle δ, which is approximately 10 degrees.
Cap 40 is preferably machined from 8620-C steel and then hardened to a Rockwell C hardness of about 61.
The assembly 30 is assembled by first threading the collet sleeve 100 to the draw bar 12 and then securing the mount 60 to the spindle 10 with screws 63 . The collet sleeve 100 is rotated until one of the slots 108 is aligned with the radial keyhole 75 formed in the mount 60 , and key screw 79 is then turned into the keyhole 75 to engage the aligned slot 108 . The collet 80 includes a cylindrical extension 99 having an outside diameter slightly smaller than the diameter of the opening 50 of the quick-change cap 40 . The collet 80 is coupled to the cap by inserting the cylindrical extension 99 into the opening 50 . The quick-change cap 40 is secured to the mount 60 by engagement of the cap-engaging structure of the mount 60 with the mount-engaging structure of the cap 40 when the cap 40 is in a cap-locked position with respect to the mount 60 . More particularly, the collet 80 and quick-change cap 40 are coupled to the mount 60 by securing the lugs 46 of the quick-change cap 40 behind the radial flanges 72 of the mount 60 (as will be described in more detail below) while compressing the collet spring 36 . The beveled annular shoulder 98 of the collet 80 bears against the beveled surface 52 of the quick-change cap 40 , both surfaces having approximately the same beveled angle.
Collet spring 36 urges the collet 80 against the quick-change cap 40 which is held axially immovable by the engagement thereof with the mount 60 , thus maintaining the annular front end face 94 in a fixed position with respect to the mount 60 . Expansion and contraction of the segments 89 of the collet 80 during opening and closing thereof is effected by relative axial movement of the collet sleeve 100 , as actuated by the draw bar 12 , with respect to the collet 80 , thereby causing relative movement between the tapered cam surfaces 82 , 102 . Because the collet 80 is held axially fixed while the collet sleeve 100 moves axially with respect to the collet 80 , the axial position of the collet 80 does not change regardless of the diameter of the workpiece secured within the collet 80 .
The manner in which the quick-change cap 40 is operatively secured to the mount 60 will now be described in detail.
An anti-rotation pin 130 is disposed within the axial aperture 67 formed in the mount 60 . Anti-rotation pin 130 generally includes an enlarged portion 132 with a slot 134 formed therein, and an extension portion 136 extending from an end of the enlarged portion 132 . Anti-rotation pin 130 is preferably formed from 8620-C steel and is hardened to a Rockwell C hardness of about 61. The anti-rotation pin 130 is inserted into the axial opening 67 with a coil spring 128 disposed at the blind end of the opening 67 and with the extension portion 136 of the anti-rotation pin 130 extended into the spring 128 .
A pin-actuating cam 140 is disposed within the cam aperture 65 formed in the mount 60 . As shown in FIGS. 6A-6C, the pin-actuating cam 140 includes a cylindrical main body 142 having a central blind aperture 144 formed therein and a radial slot 146 extending from the aperture 144 . An arcuate peripheral slot 148 is formed in an outer surface of the main body 142 , and an eccentric protrusion 150 extends from a bottom surface of the cylindrical main body 142 .
Pin-actuating cam 140 is preferably formed from 8620-C steel and is hardened to a Rockwell C hardness of about 61.
The pin-actuating cam 140 is placed in the cam aperture 65 of the mount 60 with the eccentric protrusion 150 engaging the slot 134 of the anti-rotation pin 130 . A retaining screw 37 , having a threaded portion 38 and a non-threaded lead portion 39 , is turned into the axial aperture 66 having like threads until the lead portion 39 of retaining screw 37 extends into the arcuate slot 148 formed in the cam 140 . Cam 140 is thereby held in the cam aperture 65 by the retaining screw 37 and is permitted to rotate within the cam aperture 65 over the angular extent of the slot 148 , which is preferably 90 degrees.
A rotation tool 120 , shown in FIG. 4, is provided for use with the collet chuck assembly 30 . Rotation tool 120 includes a T-handle 122 , a shaft 124 , and a radial dowel 126 extending from the end of the shaft 124 . Tool 120 is preferably formed from 8620-C steel and is hardened to a Rockwell C hardness of about 35.
The end of the tool 120 is inserted into the cam 140 disposed in the cam opening 65 . The diameter of the shaft 124 fits inside the diameter of the central blind aperture 144 formed in the cam 140 , and the radial extent of the dowel 126 conforms to the radial extent of the slot 71 . Spring 128 urges the anti-rotation pin 130 forwardly in an extended position so as to project past the annular shoulder 73 of the mount 60 . The engagement of the slot 134 with the eccentric protrusion 150 of the cam 140 rotates the cam so that, in this biased position, the slot 146 of the cam 140 is aligned with the radial slot 71 of the mount 60 . Accordingly, when the tool 120 is inserted into the cam 140 , dowel 126 engages the slot 146 of the cam. Tool 120 can then be turned (counter-clockwise in the illustrated embodiment) to rotate the cam 140 , thereby retracting the anti-rotation pin 130 into the aperture 68 by the camming action of the eccentric protrusion 150 in the slot 134 .
To install the quick-change cap 40 onto the mount 60 , the anti-rotation pin 130 is first retracted using the rotation tool 120 . Quick-change cap 40 is oriented with respect to mount 60 so that the cutouts 47 between the lugs 46 of the quick-change cap 40 are aligned with the radial flanges 72 of the mount 60 . Because the flanges 72 and lugs 46 are asymmetrically arranged about the mount 60 and quick-change cap 40 , respectively, the cutouts 47 are aligned with the flanges 72 in only one orientation of the quick-change cap 40 with respect to the mount 60 . Quick-change cap 40 is then pressed onto the mount 60 so that the annular end face 43 contacts the annular shoulder 73 of the mount 70 , thereby coupling the cap 40 to the mount 60 . Dowel 74 protruding into the channel 81 of the mount 60 contacts one of the lugs 46 of the quick-change cap 40 , thereby providing a hard stop which permits rotation of the quick-change cap 40 with respect to the mount 60 in only one direction, thereby ensuring that pin 130 and hole 48 are oriented in mating positions.
Cap 40 is rotated a portion of a single revolution with respect to the mount 60 until an anti-rotation hole 48 is aligned with the anti-rotation pin 130 . In this cap-locked position, the lugs 46 of the cap 40 are behind the flanges 72 of the mount 60 , thereby preventing axial displacement of the cap 40 with respect to the mount 60 . As shown in FIG. 5E, anti-rotation hole 48 is preferably slightly elongated in the radial direction so as to compensate for slight misalignments between the hole 48 and the anti-rotation pin 130 . As shown in FIG. 3C, spring biased plungers 83 are preferably installed in drilled and tapped holes formed in the annular shoulder 73 of the mount 60 . In the preferred embodiment, three equally spaced plungers 83 are provided. Plungers 83 engage mating detents 56 formed in the annular end face 43 of the quick-change cap 40 (see FIG. 5B) to assist in aligning the anti-rotation hole 48 with the anti-rotation pin 130 .
The tool 120 is then rotated (clockwise in the illustrated embodiment) to permit the spring 128 to urge the anti-rotation pin 130 into engagement with the anti-rotation hole 148 to link the cap 40 to the mount 60 , thereby preventing rotation of the cap 40 with respect to the mount 60 . A spring plunger 78 inserted into the tangential aperture 68 of the mount 60 engages a detent 138 formed in the side of the anti-rotation pin 130 to assist in holding the anti-rotation pin 130 in the extended position. With the tool 120 thus rotated, dowel 126 is again aligned with slot 71 formed in the mount 60 so that the tool may be removed from the cam 140 . Note that because of the arrangement of the radial slot 71 and the arcuate slot 69 of the mount 60 , the tool 120 cannot be retracted from the pin-actuating cam 140 until the cam rotates to a position in which the anti-rotation pin 130 is extended to engage the anti-rotation hole 48 of the quick-change cap 40 .
While the anti-rotation cam 140 operated by the tool 120 constitutes a preferred pin-actuating mechanism for moving the anti-rotation pin 130 between extended and retracted positions, other mechanisms for effecting movement of the pin 130 may be used as well. For example a linearly sliding pin-actuating mechanism can be installed in an outer wall of the mount and coupled to the anti-rotation pin 130 so that sliding movement of the mechanism will cause corresponding movement of the pin 130 . It is especially preferred, however, that the pin actuating mechanism be constructed and arranged so that a tool for moving the mechanism and causing corresponding movement of the pin 130 can only be disengaged from the mechanism when the pin is in the extended position. This provides a safety check to the user so that the tool is not disengaged from the pin-actuating mechanism before the pin 130 has extended into the aperture 48 of the cap 40 and thereby locked the cap 40 with respect to the mount 60 .
Thus, it can be appreciated that the collet 80 can be installed by simply inserting it into the sleeve 100 and installing the cap 40 in the simple manner described above. Removing the collet 80 is equally simplified. The sleeve 100 is engaged with the draw bar 12 and need not be disengaged every time the collet 80 is removed. Accordingly, the collet 80 need not be disengaged from the draw bar when removed or engaged with the draw bar when installed.
An alternate collet 180 for use with the assembly of the present invention is shown in FIG. 7 in which features that are common to the collet 80 shown in FIGS. 1 and 2 have corresponding reference numbers. Collet 180 is a solid collet having segments 189 with solid portions 182 defining an axial opening 185 therethrough. Solid portions 182 define aback annular edge 184 . Solid collet 180 can be custom bored by the end user to accommodate a particular size of tool or workpiece. Accordingly, collet 180 does not require collet pads and therefore a collet pad clamp and the corresponding openings 86 shown on the master collet 80 are not necessary for the solid collet 180 .
Solid collet 180 is preferably machined from the same material and given the same heat treatment as collet 80 described above.
An optional feature which may be advantageously employed with the collet assembly 30 of the present invention is a rear guide bushing 160 shown in FIG. 8 . Bushing 160 includes a body 162 with a first end face 164 and a second end face 166 . A first conical section 168 and a second conical section 172 , separated by a cylindrical section 170 , are formed so as to extend from the second end face 166 . First and second conical sections 168 , 172 are preferably formed at an angle γ of approximately 132 degrees. A through hole 173 is formed centrally through the second conical section 172 to the first end face 164 . The rear guide bushing 160 can be installed into a rear end of a collet 80 ( 180 ) by turning external threads 174 formed in the outer surface of the body 162 into internal threads 88 formed on the interior of the collet 80 ( 180 ). A custom-sized through hole, indicated by phantom lines 176 , can be formed centrally through the rear guide bushing 160 by an end user. The rear guide bushing 160 facilitates alignment of elongated bar stock inserted from the rear of a machine, such as a lathe, with the collet 80 ( 180 ). With a solid collet 180 or with collet pads installed in a master collet 80 , alignment of the bar stock with the collet opening, such as collet opening 185 formed in solid collet 180 , can be difficult without the benefit of the rear guide bushing 160 .
Bushing 160 is preferably formed from 8620-C steel and is hardened to a Rockwell C hardness of about 35.
Another optional feature that can be advantageously used in conjunction with the collet assembly of the present invention is a solid stop assembly 190 , as shown in FIG. 9 . The solid stop assembly 190 includes a solid stop body 196 having external threads 198 formed on the outer periphery thereof and a centrally formed threaded aperture that is engaged by a threaded stop rod 194 . Solid stop body 196 is preferably formed from steel and is hardened to a Rockwell C hardness of about 35. A nut 192 secures the stop rod 194 with respect to the body 196 . A slot 200 may be formed in one end of the stop rod 194 to facilitate adjustment of the rod 194 with a tool such as a screwdriver. Solid stop assembly 190 can be secured to a collet 80 ( 180 ) by turning the external threads 198 of the body 196 into the internal threads 88 of the collet 80 ( 180 ). With the solid stop assembly installed in a collet 80 ( 180 ), the stop rod 194 limits the extent to which a workpiece can be inserted into the collet 80 ( 180 ), thereby permitting repeatable positioning of the workpiece in the collet. The construction, function, and operation of the solid stop assembly is similar to a solid stop assembly disclosed in U.S. Pat. No. 5,330,224, the disclosure of which is hereby incorporated by reference.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Furthermore, it should be noted that where the appended claims do not include language in the ‘means for performing a specified function’ format permitted under 35 U.S.C. §112(¶6), it is intended that the appended claims not be interpreted under 35 U.S.C. §112(¶6) as being limited to the structure, material, or acts described in the present specification and their equivalents. | A collet chuck assembly includes an annular mount adapted to be attached to a spindle of a turning machine, a tubular collet sleeve disposed internally to the mount including an inner tapered cam surface and adapted to be coupled to an axial moving mechanism of the turning machine, and a tubular collet structure dispose interiorly of the collet sleeve and having a cooperating tapered, outer cam surface. An annular retaining cap has retaining lugs adapted to be engaged with locking flanges of the mount upon engagement of the cap with the mount and rotation of the cap with respect to the mount. The installed cap engages a front end of the collet structure to retain the collet structure within the collet sleeve. A cap anti-rotation mechanism includes an anti-rotation pin carried within the mount for reciprocating axial movement with respect to the mount between extended and retracted positions and a pin actuating mechanism for selectively effecting the reciprocating axial movement. When in the extended position, the anti-rotation pin engages the cap to prevent rotation of the installed cap with respect to the mount. The cap can be rotated with respect to the mount and removed therefrom be moving the anti-rotation pin to the retracted position. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to Korean Patent Application No. 10-2010-0083881 filed on Aug. 30, 2010, the entire contents of which is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to airbag apparatuses for vehicles and, more particularly, to an airbag apparatus which is installed in a roof of a vehicle so that when a vehicle collision occurs, an airbag is deployed to protect a passenger.
[0004] 2. Description of Related Art
[0005] Hitherto, development of airbag apparatuses for vehicles has been focused on protecting front seat passengers.
[0006] However, when a vehicle is involved in a frontal collision, a rear seat passenger that is not wearing a safety belt may injure his/her head as a result of colliding with the head of a passenger in the front seat or with the back of the front seat. Taking into account the fact that the percentage of rear seat passengers who wear safety belts is much lower than that of front seat passengers, the development of airbag apparatuses that protect rear seat passengers is more aggressively required.
[0007] As shown in FIG. 5 , in consideration of the above facts, an airbag apparatus of a vehicle for protecting a rear seat passenger was proposed. This conventional airbag apparatus is installed in space between a roof panel 10 and a headliner 20 of the vehicle. When a vehicle collision occurs, a cushion 30 tears the headliner 20 , protrudes outs of the headliner 20 , and then is deployed into the space between the front seat and the rear seat passenger.
[0008] However, in the conventional airbag apparatus, the cushion 30 is instantaneously inflated just in front of the face of a passenger 40 . As a result, the head or neck of the passenger 40 may be injured by the cushion 30 that is inflated at high pressure.
[0009] 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
[0010] Various aspects of the present invention are directed to provide an airbag apparatus for a vehicle which is configured such that gas smoothly flows in an airbag cushion so that when a vehicle collision occurs, the airbag cushion can effectively protect a passenger.
[0011] In an aspect of the present invention, the airbag apparatus for a vehicle may include an inflator, and an airbag cushion having a depressed head support portion formed in a rear portion of the airbag cushion so that when the airbag cushion may be deployed by gas supplied from the inflator, the head support portion receives a head of a passenger, and shoulder support portions protruding from lateral sides of the head support portion in a rearward direction and forming a space between the shoulder support portions to may have the head support portion therebetween when the airbag cushion may be deployed, and a support tether provided in the airbag cushion and extending in a transverse direction across the shoulder support portions such that a gas path may be defined in a front portion of the airbag cushion below the support tether, the gas path guiding the gas downwards.
[0012] An airbag screen may be attached to the shoulder support portions, the airbag screen covering the head support portion.
[0013] The support tether connects the head support portion and inner surface of the airbag cushion, wherein the support tether may include an upper support tether and a lower support tether spaced apart from each other by a predetermined distance in a vertical direction of the airbag cushion.
[0014] Rear and side edges of the support tether may be respectively connected to a rear surface of the head support portion and sidewalls of the airbag cushion by sewing so that the support tether encloses the head support portion, wherein a front edge of the support tether may be not connected to the inner surface of the airbag cushion and may have a round shape.
[0015] The front edge of the support tether may have a convex shape protruding along gas passage of the inflator.
[0016] The airbag apparatus may further may include a housing provided in a space between a roof panel and a headliner of the vehicle, the housing containing the airbag cushion, wherein the airbag cushion may include a roof support panel supported by the headliner and receiving the gas through a gas inlet formed thereon, a vertical support panel perpendicularly connected at an upper end line thereof to a rear end line of the roof support panel, a ramp support panel connecting a front end line of the roof support panel to a lower end line of the vertical support panel at an inclined angle, and side support panels connecting side edge lines of the roof support panel, the vertical support panel, the ramp support panel, and the support tether.
[0017] The present invention has the following effects.
[0018] First, gas can smoothly flow in the front portion of an airbag cushion. Therefore, the time it takes the airbag cushion to be completely deployed is shortened, which makes the deployment of the airbag smooth and reliable.
[0019] Second, the airbag cushion is supported by a headliner in a reverse right-triangular shape. Therefore, the cushion can effectively absorb impact applied to the passenger and thus maintain the passenger in a stable position.
[0020] Third, when the airbag cushion is deployed, a depressed head support portion of the airbag cushion can maintain the head of the passenger in a stable position. Hence, the cushion can more effectively absorb the impact applied to the passenger when the cushion is deploying.
[0021] Fourth, the present invention can reduce impact applied to the head of the passenger when the airbag cushion is supporting the position of the passenger, thus minimizing injury to the passenger, and fundamentally preventing the neck of the passenger from being bent by the inflation pressure of the airbag cushion.
[0022] 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
[0023] FIG. 1 is a view showing the structure of an airbag apparatus for vehicles, according to an exemplary embodiment of the present invention.
[0024] FIG. 2 is a view showing the structure of an airbag cushion of the airbag apparatus, according to an exemplary embodiment of the present invention.
[0025] FIG. 3 is a longitudinal sectional view taken along the line A-A of FIG. 2 .
[0026] FIG. 4 is a cross-sectional view taken along the line B-B of FIG. 2 .
[0027] FIG. 5 is a view showing an airbag apparatus for vehicles, according to a conventional technique.
[0028] It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.
[0029] In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.
DETAILED DESCRIPTION OF THE INVENTION
[0030] 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.
[0031] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the attached drawings.
[0032] As shown in FIGS. 1 and 2 , in an airbag apparatus according to an exemplary embodiment of the present invention, a gas path 230 is formed in a front portion of an airbag cushion 200 such that the flow of gas is smooth. A depressed head support portion 210 is formed in a rear portion of the airbag cushion 200 to effectively absorb impact applied to the head of a passenger 630 .
[0033] To achieve these purposes, the airbag apparatus includes an inflator 100 , the airbag cushion 200 and a support tether 300 .
[0034] The inflator 100 supplies gas into the airbag cushion 200 when a vehicle collision occurs. Preferably, the inflator 100 is installed in a housing 500 provided in space between a roof panel 610 and a headliner 620 .
[0035] The housing 500 is a casing which contains the airbag cushion 200 therein. The inflator 100 is installed in a predetermined portion of the housing 500 to supply gas into the airbag cushion 200 . Particularly, a lower surface of the housing 500 may be covered with the headliner 620 or, alternatively, it may be exposed out of the headliner 620 to the passenger compartment. In the case where the housing 500 is covered with the headliner 620 , a tear line is provided on the headliner 620 to ensure deployment of the airbag cushion 200 . In the case where the housing 500 is exposed to the passenger compartment through the headliner 620 , an airbag door is provided in the lower surface of the housing 500 to ensure deployment of the airbag cushion 200 .
[0036] In this embodiment, although the inflator 100 and the airbag cushion 200 have been illustrated as being installed in the housing 500 provided in the space between the roof panel 610 and the headliner 620 , the inflator 100 and the airbag cushion 200 may be directly installed in the space between the roof panel 610 and the headliner 620 without a separate housing being used.
[0037] As shown in FIGS. 3 and 4 , when a vehicle collision occurs, the airbag cushion 200 is deployed downwards by gas supplied from the inflator 100 so as to protect the passenger 630 . The airbag cushion 200 includes a roof support panel 201 , a vertical support panel 202 , a ramp support panel and side support panels 204 such that a gas inlet 250 , the head support portion 210 , the gas path 230 and shoulder support portions 220 are formed. Thereby, the airbag cushion 200 can minimize the impact applied to the head of the passenger 630 when it is deployed.
[0038] In detail, the roof support panel 201 is a support panel which is in contact with the headliner 620 . The gas inlet 250 is formed in a predetermined portion of the roof support panel 201 . When a vehicle collision occurs, gas is supplied from the inflator 100 into the entire space of the airbag cushion 200 through the gas inlet 250 .
[0039] Furthermore, front and rear end lines of the roof support panel 201 are respectively connected to an upper end line 216 of the vertical support panel 202 and an upper end line 214 of the ramp support panel 203 . Both side lines of the roof support panel 201 are connected to respective upper end lines of the side support panels 204 .
[0040] The vertical support panel 202 forms the rear surface of the airbag cushion 200 . The upper end line 216 of the vertical support panel 202 is connected to the rear end line of the roof support panel 201 such that the vertical support panel 202 is perpendicular to the roof support panel 201 .
[0041] The ramp support panel 203 connects a front end line of the roof support panel to a lower end line 218 of the vertical support panel 201 .
[0042] The vertical support panel 202 forms the head support portions 210 and the shoulder support portions 220 are provided between the head support portions 210
[0043] The depressed head support portion 210 holds the head of the passenger 630 when a vehicle collision occurs. The head support portion 210 is formed in the rear portion of the airbag cushion 200 and has a depressed shape corresponding to the head of the passenger 630 . Thus, when the airbag cushion 200 is deployed, the head of the passenger 630 is inserted into the head support portion 210 , so that impact force applied to the head of the passenger 630 can be effectively absorbed by inflation force of the airbag cushion 200 .
[0044] Particularly, the head support portion 210 is inclined downwards and rearwards such that the depth thereof is reduced from the top towards the bottom of the airbag cushion. The reason for this is to make the shape of the head support portion 210 correspond to the outline of the head and the neck of the passenger 630 .
[0045] Thereby, the head support portion 210 can reliably protect the head and the neck of the passenger 630 . The shoulder support portions 220 are disposed on opposite sides of the head support portion 210 and configured such that when the airbag cushion 200 is deployed, they protrude from the head support portion 210 towards the shoulders of the passenger 630 . Thus, when the head of the passenger 630 is supported by the head support portion 210 , the shoulders of the passenger 630 can be stably supported by the shoulder support portions 220 .
[0046] The ramp support panel 203 forms the front surface of the airbag cushion 200 . The upper end line of the ramp support panel 203 is connected to the front end line of the roof support panel 201 such that the ramp support panel 203 forms a predetermined angle with the roof support panel 201 . The gas path 230 is defined in the airbag cushion 200 at a position adjacent to the ramp support panel 203 . The gas path 230 forms a path between the ramp support panel 203 and the support tether 300 along which gas flows. Thereby, the flow of gas becomes smooth, and the time it takes for the airbag cushion 200 to be completely deployed is reduced, thus making it possible to deploy the airbag cushion 200 reliably and smoothly.
[0047] The side support panels 204 form the opposite sidewalls of the airbag cushion 200 and connect side edge lines of the roof support panel 201 , the vertical support panel 202 and the ramp support panel 203 to each other.
[0048] The support tether 300 is provided in the airbag cushion 200 to maintain the entire shape of the airbag cushion 200 .
[0049] The support tether 300 has a “U” shape. Rear and side edges of the support tether 300 are respectively connected to the rear surface and the sidewalls of the airbag cushion 200 , in other words, the vertical support panel 202 and the side support panels 204 , by sewing.
[0050] The support tether 300 includes an upper support tether 300 a and a lower support tether 300 b which are spaced apart from each other by a predetermined distance with respect to the vertical direction of the airbag cushion 200 . Front edges of the upper and lower support tethers 300 a and 300 b have a round shape (R) to form the gas path 230 along which gas flows.
[0051] The airbag cushion 200 having the above-mentioned structure generally has a reverse right-triangular shape. The airbag cushion 200 having this shape can effectively absorb impact applied to the passenger 630 when a vehicle collision occurs.
[0052] Particularly, the front surface of the airbag cushion 200 is inclined and curved downwards and rearwards to prevent it from being impeded by the front seat when the airbag cushion 200 is being deployed. In detail, the front surface of the airbag cushion 200 has a shape corresponding to a track along which a head rest of the front seat moves when the front seat back is tilted forwards or rearwards. Thus, the airbag cushion 200 can be smoothly deployed without interruption.
[0053] Meanwhile, an airbag screen 400 is attached to the shoulder support portions 220 of the airbag cushion 200 . The airbag screen 400 covers the head support portion 210 . For example, for the case where the airbag screen 400 is attached to the shoulder support portions 220 , the shoulder support portions 220 are supported relative to each other by the airbag screen 400 . Thereby, the space between the shoulder support portions 220 can be prevented from widening to the left and the right. On the other hand, if no airbag screen is attached to the shoulder support portions 220 , when the airbag cushion 200 is deployed, the space between the shoulder support portions 220 widens to the left and the right based on the head support portion 210 , because the shoulder support portions 220 cannot be supported relative to each other.
[0054] Therefore, in an exemplary embodiment of the present invention, when the airbag cushion 200 is deployed by a vehicle collision, the face of the passenger 630 is covered by the airbag screen 400 and stably supported by the head support portion 210 . Thereby, impact applied to the head of the passenger 630 can be effectively absorbed by the airbag cushion 200 while it is deploying.
[0055] As described above, in an exemplary embodiment of the present invention, when the airbag cushion 200 is deployed in the case of a vehicle collision, gas can smoothly flow in the front portion of the airbag cushion 200 . Therefore, the time it takes the airbag cushion 200 to be completely deployed is reduced, thus making the deployment of the airbag smooth and reliable. Furthermore, the depressed head support portion 210 of the airbag cushion 200 holds the head of the passenger 630 at the initial stage of the deployment of the airbag cushion 200 . Hence, the airbag cushion 200 can effectively absorb impact applied to the passenger 630 .
[0056] For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0057] 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 apparatus for a vehicle may include an inflator, and an airbag cushion having a depressed head support portion formed in a rear portion of the airbag cushion so that when the airbag cushion may be deployed by gas supplied from the inflator, the head support portion receives a head of a passenger, and shoulder support portions protruding from lateral sides of the head support portion in a rearward direction and forming a space between the shoulder support portions to have the head support portion therebetween when the airbag cushion may be deployed, and a support tether provided in the airbag cushion and extending in a transverse direction across the shoulder support portions such that a gas path may be defined in a front portion of the airbag cushion below the support tether, the gas path guiding the gas downwards. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to improved clips for releasably retaining a sheet of abrading material, such as sandpaper, on an abrading tool.
One structurally very simple type of clip which is currently in use for releasably retaining a sheet of sandpaper or the like on an abrading tool includes a clamping element made of sheet form spring material which is bent to have an edge which engages an end of the sandpaper sheet and clamps it against a backing surface. The clamping element is movably mounted by a link member which is pivoted to a support structure for swinging movement about an axis located behind the backing surface, and which is connected to the clamping element for relative pivotal movement about a second axis. In actuating the clamping element to a sandpaper retaining condition, the link swings about the first axis in a relation moving the second mentioned axis to an overcenter position in which the discussed edge of the clamping element is urged tightly against the sandpaper sheet. The retention of the sandpaper by this type of device is in some respects very effective, but is of a nature requiring the exercise of considerable care in pulling the sandpaper tight on the tool during actuation of the clip to clamping condition.
SUMMARY OF THE INVENTION
A major purpose of the present invention is to provide a clip which is of the above discussed general type, but which is specially constructed to have an automatic take-up action, functioning to inherently exert a pulling force on the ends of the abrasive sheet, in a manner effectively maintaining the sheet in taut condition on the shoe of a sander or the like, and continually taking up any looseness in the sandpaper sheet which may initially be present or develop in use of the tool. This take-up action is achieved with no increase in complexity of the clip structure, and is attained without adverse effect on the positive clamping action of the device.
To provide for the take-up action, the backing surface against which the sandpaper sheet is clamped by the spring clamping element is in the present device disposed at a slight camming angle with respect to the remainder of the mechanism, so that the yielding force exerted by the spring element has a tendency to cam or urge the clamping element and engaged abrading sheet in a takeup direction. More particularly, a camming portion of this backing surface is disposed at an angle such that, as that surface advances in the direction in which the abrading sheet must be pulled to take up looseness therein, the surface simultaneously also advances slightly closer to the position which the pivotal axis between the mounting link and clamping element assumes when the device is in its locking condition. When the clamping element is initially actuated to its active clamping condition, it is positioned to contact the abrading sheet material at a location opposite a portion of the angular backing surface which is farther from the mentioned pivotal connection than are other portions of the camming surface which are offset in the take-up direction. The yielding force exerted by the clamping element then tends to force the engaged portion of the abrading sheet toward that axis, and in doing so cams the sheet in take-up direction.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing in which:
FIG. 1 is a side view of a portable power driven sander tool having sandpaper retaining clips constructed in accordance with the invention;
FIG. 2 is an enlarged fragmentary side view showing one of the clips of the FIG. 1 tool, with the clip illustrated in its active clamping condition;
FIG. 3 is a view similar to FIG. 2, but showing the clip in released condition;
FIG. 4 is a fragmentary plan view taken on line 4--4 of FIG. 2;
FIG. 5 is a vertical section taken on line 5--5 of FIG. 3; and
FIG. 6 is an end view taken on line 6--6 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The powered sander 10 of FIG. 1 includes a portable body 11 having a handle portion 12 and which movably carries at its underside an abrading unit 13 to which a sheet of sandpaper or other abrading material 14 is connected by a pair of spring clips 15. The shoe 13 and carried sandpaper are driven relative to body 11 by a motor 16 carried by the body, in any desired type of sanding movement, such as orbitally about a vertical axis 17, or in a straight line reciprocating motion along a front to rear axis 18 of the tool.
The shoe 13 extends essentially horizontally in the FIG. 1 position of the tool, and is illustrated as positioned for sanding the upper horizontal surface 19 of the workpiece 20. As seen best in FIGS. 2 and 3, the shoe 13 may include an upper rigid horizontal plate 21, which is preferably formed of sheet aluminum and is driven by motor 16, and which may have parallel upwardly turned vertical flanges 22 extending along its opposite side edges. At the underside of plate 21, the shoe includes a layer of cushioning material 23, which may be formed of rubber whose upper surface is bonded continuously to plate 21 and whose undersurface 24 extends horizontally in the illustrated position of the tool and may be irregularized. At their opposite ends, the parts 21 and 23 of shoe 13 are cut off in vertical parallel planes 25 and 26 disposed transversely of the front to rear axis 18 of the tool to provide end edges 28 of parts 21 and 23 lying in those planes.
The sandpaper sheet 14 extends horizontally along the undersurface 24 of shoe 13, and at its opposite ends is turned upwardly at 29 to have an essentially vertical portion 30 at each end retained by the corresponding clip 15 to hold the sandpaper on the shoe.
The two clip assemblies 15 may be identical, and consequently only one of these assemblies has been illustrated in detail in FIGS. 2 to 6. With reference to those figures, each of these clips may include a base or mounting part 31, a clamping element 32, and a connecting link 33. The part 31 may be stamped from sheet metal, preferably steel, of a composition and thickness sufficient to render the part 34 essentially rigid, though it is contemplated that if desired the part may have some very slight resilient deformability under the forces exerted by clamping element 32 in use. Part 31 may be shaped to have a main horizontal mounting portion 34 secured to the upper surface of part 21 by screws 35 extending through registering apertures in parts 21 and 34 and carrying nuts 36 at their upper ends. At the locations of the end edges 28 of parts 21 and 23 of the shoe, base element 31 is bent upwardly at 37 to form an upwardly extending flange 38 having a backing surface 39 against which the back side of sander sheet 14 is engageable. At a location behind flange 38 (leftwardly in FIGS. 2 and 3), there are stamped out of portion 34 of part 31 a pair of upstanding parallel mounting lugs 40, lying in a pair of vertical planes 41 which are parallel to and symmetrical with respect to the front to rear axis 18 of the tool. These lugs 40 mount link 33 for pivotal movement relative to part 31 about a horizontal axis 42 which extends transversely of the tool (i.e. parallel to the end planes 25 and 26 of the shoe). For this purpose, link 33 may have end portions 43 which are turned inwardly toward one another along axis 42 and through aligned apertures 44 in parts 40 to mount the link for the desired pivotal swinging movement between the active clamping position of FIG. 2 and the retracted or open position of FIG. 3.
Link 33 may be formed of a single length of rigid externally cylindrical wire or rod material, bent to have the generally U-shaped configuration illustrated in FIG. 5. More particularly, the link may have a main cross piece portion 45 extending along an axis 46 which is parallel to axis 42, with a pair of parallel arms 47 of the link projecting from portion 45 and carrying at their extremities the previously mentiond inwardly turned terminal portions 43 of the link.
Clamping part 32 is stamped from sheet form spring material, desirably spring steel, which normally returns by its resilience to the condition or shape illustrated in FIGS. 3, 5 and 6, but which is slightly deformed in the FIG. 2 condition to exert a strong yielding spring force against the sandpaper for tightly clamping it against flange 38. At its right end as viewed in FIGS. 2 and 3, the clamping spring 32 has a portion 48 which can extend downwardly in front of or opposite flange 38, and which has a portion 49 turned inwardly toward the flange to present an edge 50 adapted to engage the abrasive side of sandpaper sheet 14 and press it against the flange. Edge 50 is narrow vertically to engage the sandpaper opposite only a localized portion of the backing surface 39 of flange 38, and may follow essentially a straight line extending transversely of the shoe and parallel to surface 39. Portions 48 and 49 and edge 50 of the clamping spring are desirably of a width w transversely of the shoe corresponding essentially to the width of the shoe itself and part 31 and its flange 38.
In extending upwardly from its portions 48 and 49, the clamping spring 32 curves gradually rearwardly at 51, and then has a portion 52 of a reduced width x (FIG. 4) which curves downwardly and rearwardly to a location at which return bend portion 53 is looped essentially circularly about portion 45 of link 33 to form a pivotal connection therewith, connecting the clamping spring 32 to the link for relative pivotal movement about the previously mentioned axis 46. After being doubled back about portion 45 of the link, the material of clamping spring 51 is shaped to form a resricted gap 54 of a width less than the diameter of portion 45 of the link to effectively lock the link in its pivotally connected position with respect to the spring, while at the same time allowing initial connection of the parts by forcing portion 45 of the link past a camming surface 55 of the spring to temporarily spread the spring to increase the width of gap 54 as the parts are moved together. After such connection, the strength of the material of clamping spring 32 is sufficient to prevent detachment of parts 32 and 33 from their pivotally interconnected condition under the influence of forces encountered in use. At the upper side of part 32, the material of this part is cut and shaped to form a pair of upwardly turned handle or actuating tabs 56, located at opposite sides of the portion 52 of part 32, and adapted to be utilized for manually actuating the clamping part between its FIG. 2 and FIG. 3 positions.
In the FIG. 2 active clamping condition of the device, the counterclockwise swinging movement of the pivotal connection 57 between parts 32 and 33 is limited by engagement of the return bend hinge portion 53 of part 32 with the upper surface of horizontal portion 34 of the base part 31 of the clip assembly. In that clamping condition of FIG. 2, the axis 46 of pivotal connection 57 is slightly overcenter with respect to axis 42 of the other pivotal connection 58 and clamping edge 50 of part 32. That is, in this clamping condition of FIG. 2 a line or plane 59 extending between axis 46 and edge 50 is located downwardly beyond or overcenter with respect to axis 42, to thereby positively retain the clip in this FIG. 2 condition. Under the automatic take-up action which will be discussed in greater detail hereinbelow, edge 50 may move upwardly relative to flange 38 from a location such as that shown in full lines in FIG. 2 to a predetermined uppermost clamping position represented in broken lines at 32' in FIG 2. In that uppermost position, the line or plane extending between axis 46 and edge 50 is positioned as illustrated at 59'. It is noted particularly that the discussed overcenter relationship between the parts remains even in this uppermost position 59' of the clamping element, and of course in all intermediate positions between those represented at 59 and 59', and any settings to which the clamping part may be moved lower than the one represented in full lines in FIG. 2.
To attain the automatic take-up action, flange 38 is so shaped that its backing or clamping surface 39 has a main camming portion 60, extending upwardly from the location 37 to a location 61. At each point along the entire vertical extent of this camming portion 60, surface 39 is disposed at a camming non-perpendicular angle with respect to a line (such as 59 or 59') extending from the FIG. 2 active position of axis 46 to that particular portion of the camming surface. This camming angularity is represented in FIG. 2 by illustration at 62 of a plane disposed perpendicular to the line 59' which extends from axis 46 to the uppermost portion 61 of the camming surface, and by representation at 63 of the plane of the camming portion 60 of surface 39, with the angle a between these planes representing the deviation of the camming surface from a precisely perpendicular condition with respct to line 59'. At the location of the line 59 of FIG. 2, this deviation from perpendicularity is slightly greater than the illustrated angle a. However, at all locations along the vertical extent of camming portion 60 of backing surface 39, the angle of deviation from perpendicularity is rather small, and is preferably not greater than about 20° (optimally between about 5° and 15°). It is noted that this angularity is in a direction such that, as the camming portion 60 of surface 39 advances upwardly from its lowermost portion 37, that camming surface gradually advances closer to the axis 46, so that a yielded force exerted leftwardly by the resilience of spring 32 against the sandpaper at the location of edge 50 will, by tending to urge the sandpaper toward axis 46, exert an upward camming force against the sandpaper causing it to be automatically tightened on the shoe, and will do so at all positions of the clamping edge 50 between a lowermost position opposite the bottom portion of flange 38 and the uppermost position represented in broken lines at 32' in FIG. 2.
Upwardly beyond the upper edge 61 of camming portion 60 of surface 39, the surface 39 has a portion 64 which reverses its direction of advancement, in that as portion 64 continues upwardly it commences to advance farther away from rather than closer to axis 46, so that the discussed camming action must terminate at the broken line position 32' of FIG. 2, and the discussed portion 64 of surface 39 acts as a stop limiting upward movement of edge 50 relative to the flange. This reverse angularity of portion 64 with respect to the perpendicular plane 62 is represented by the angle b of FIG. 2. At the juncture of the portions 60 and 64 of surface 39, there is then formed a horizontal valley at the previously mentioned location 61, toward which valley the camming action urges edge 50.
In attaching the sandpaper sheet 14 to shoe 13, the sandpaper is first positioned adjacent the undersurface of the shoe with the abrasive particles of sheet 14 facing downwardly, following which the opposite ends of the sheet are turned upwardly for reception between the two clamping springs 32 and their corresponding flanges 38. During initial insertion of the ends of the sandpaper sheet between these parts, clamping spring 32 is of course in a released position similar to that shown in FIG. 3. After an end of the sandpaper sheet has been positioned between the corresponding flange 38 and element 32, a user exerts force against the handle lugs 56 (leftwardly in FIG. 3), to swing link 33 and the carried part 32 to the FIG. 2 active positions. During such swinging movement, the user exerts downward force on part 32 to cause its edge 50 to be received opposite a lower portion of flange 38, as far beneath the location 61 as possible. The final swinging movement of parts 32 and 33 to the overcenter position of FIG. 2 causes edge 50 to be pulled tightly against the sandpaper sheet, at a location opposite a lower portion of flange 38 as illustrated in FIG. 2. Engagement of edge 50 with the irregularities formed by the sanding particles 70 on the surface of sandpaper sheet 14 prevents movement of edge 50 upwardly relative to the sandpaper sheet, so that any upward movement of edge 50 will cause corresponding upward movement of the engaged portion of the sheet by virtue of this interfitting relation between edge 50 and the projections on the sandpaper. Spring 32 is in the FIG. 2 condition distorted slightly so that its resilience tends to urge edge 50 leftwardly toward axis 46, to attain the previously described automatic take-up action causing edge 50 and the engaged portion of the sandpaper sheet to shift upwardly as close to the broken line position 32' of FIG. 2 as is possible. This camming movement is halted when the sandpaper sheet reaches a very taut condition on shoe 13, and the continuing tendency for further camming action acts at all times to maintain that taut condition and take up any slack which may develop in the sandpaper sheet. Preferably, the clip is applied in a manner such that edge 50 never actually reaches the extreme position represented at 32' in FIG. 2, but always has a capability for further take-up action. By virtue of the very small camming angularity a of camming surface 60, the take-up action may not occur until the sander is actually placed in operation, at which time the vibrational movements of the sanding shoe under the influence of motor 16 will immediately cause the take-up action even at that slight camming angle and produce the desired taut effect of the sandpaper on the shoe.
While a certain specific embodiment of the present invention has been disclosed as typical, the invention is of course not limited to this particular form, but rather is applicable broadly to all such variations as fall within the scope of the appended claims. | A clip for holding an abrading sheet on an abrading tool, and including a clamping element of sheet form spring material which is received opposite and clamps an end of the sheet against a backing surface of a coacting structure, with the clamping element being mounted to that structure by a connecting link which swings to an overcenter position in the clamping condition of the device, and with the backing surface being disposed at a camming angle producing an automatic take-up action for tightening the sheet on the tool as necessary to maintain it in a properly taut condition. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to douche and bidet devices, and more particularly to a shower mounted douche/bidet apparatus and method.
[0002] Douche or bidet devices for use in the shower for personal cleaning, such as the device shown in U.S. Pat. No. 4,642,100, employ an elongate douche applicator spray device. However, the configuration of such an elongate device makes it difficult to hold and use. For example, insertion of the applicator into or positioning of the applicator near certain parts of the body, such as genital or rectal areas, is awkward and requires an uncomfortable positioning of the user's hands, wrist, and arms. Also, the known devices typically have 5 or 6 spray holes, oriented in different directions, which result in multiple sprays in multiple directions, which may not be desirable for a user.
SUMMARY OF THE INVENTION
[0003] In accordance with the invention, an improved shower mounted douche/bidet apparatus employs a shower ball mount arm as an applicator head.
[0004] Accordingly, it is an object of the present invention to provide an improved shower mounted douche apparatus.
[0005] It is a further object of the present invention to provide an improved shower mounted bidet apparatus.
[0006] Still a further object of the present invention is to provide an improved shower mounted douche/bidet apparatus.
[0007] It is yet another object of the present invention to provide an improved shower mounted douche/bidet apparatus not requiring a backflow prevention valve.
[0008] The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawing wherein like reference characters refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a photograph of the douche/bidet apparatus and its components, in accordance with a preferred embodiment;
[0010] [0010]FIG. 2 is a schematic side view of a shower prior to installation of the device;
[0011] [0011]FIG. 3 is a schematic side view of a shower after installation of the device;
[0012] [0012]FIG. 4 is a partial view of a handle illustrating a single stream aspect;
[0013] [0013]FIG. 5 is a perspective view of a shower head with the diverter installed;
[0014] [0014]FIG. 6 is a side view illustrating a user holding the handle, showing an exemplary flow of water; and
[0015] [0015]FIG. 7 is a view of a shower wall with the device hung thereon by use of the hook and hanger, when in a not-in-use mode.
DETAILED DESCRIPTION
[0016] The system according to a preferred embodiment of the present invention comprises a valve that selectively controls the amount of water diverted from a shower head supply to a douche/bidet head, via a flexible hose.
[0017] Referring to FIG. 1, a photograph of the douche/bidet apparatus and its components, in accordance with a preferred embodiment, the device comprises a handle “A”, suitably having an elongate portion 10 which is straight from a connection 12 at one end thereof and angles at an angle α, continuing on for a somewhat shorter portion, ending with a ball shaped head 14 . The angle α is approximately 70 degrees or so in the illustrated embodiment.
[0018] The connection 12 of the handle receives a hose “C” therein, suitably comprising a flexible type hose which extends to a side connection 16 of a diverter “B”. A sleeve 13 may be provided, in the form of a tape or such, to cover the threaded portion of the handle where it engages the hose, if desired, and to provide an aesthetic appearance. Different models employ different color sleeves 13 , which may comprise a gold metallic or silver metallic color band, with metal flake appearance, for example.
[0019] The diverter is adapted to be received by threaded portion 18 at a shower head attachment point of a typical bathroom shower. An opposite end 20 of the diverter is adapted to threadably receive a shower head thereon.
[0020] The diverter carries first and second buttons 22 , 24 thereon, which control valves therein so as to adjust the flow volume through each arm of the diverter.
[0021] In the illustrated embodiment, the diverter “B” is suitably a chrome plated, solid brass diverter which is manufactured by RESOURCES CONSERVATION INCORPORATED (“Deluxe DUAL Shower Arm Diverter #YA903). The hose “C” suitably comprises a chrome plated or stainless steel shower hose. However, an alternate hose may take the form of a vinyl tubing, for example. Handle “A” is preferably a ball type shower arm manufactured by Price Pfister and distributed for example by LASCO (Santa Fe Springs, Calif. 90670) (part #08-2463). The handle in the illustrated embodiment is chrome plated, solid brass, and is approximately six inches long, although other lengths may be desirable for different models, adapted for different users. For example, a women's model employs a longer handle portion than a men's model. In the illustrated embodiment, the length from the tip of the ball portion of the handle to the bend in the handle is approximately 2.5 inches, while the length from the bend to the handle/connection 12 interaction point is 3.5 inches. The connection 12 is about 1 inch in length in the illustrated form, and an exemplary hose length, from the junction with connection 12 to the end of the side connector 16 of the diverter is 5 feet. Of course, other lengths are possible, depending on the size and configuration of the individual shower. It should be noted that the use for which the handle was originally created and manufactured was to receive a shower head on the ball end thereof, and it is applicant who has found the new use therefor as a douche/bidet apparatus.
[0022] In use, the purpose of this product is for personal hygiene, as a handheld shower douche for men or women. The unique shape of the handle results in an ergonomic design that does not require full insertion into the body, is thus it is easier to use.
[0023] To install the device in a shower, with reference to FIG. 2 and FIG. 3, schematic view of before and after the mounting of the device, an existing showerhead is removed from the shower, and the diverter is mounted in place thereof via threaded receiving portion 18 . Then, the showerhead that was just removed is attached to the portion 20 of the diverter. Thus, the shower may continue to be used. To employ the douche/bidet, the shower is turned on as would have been done before installation. Then, by operation of the flow control buttons 22 , 24 , water is at least partially diverted from the showerhead end of the diverter to the hose. This diverted water flow then exits from the ball end of the handle as shown at 30 in FIG. 1. The handle may then be moved about as desired by the user for application of the flow to the body. In the preferred embodiment, the exiting stream of water from the head is substantially a single stream 32 , as shown in FIG. 4, a partial view of an end of the handle.
[0024] The diverter unit is advantageously usable throughout the U.S. while complying with plumbing code requirements, because it continues to drip (slightly) whenever the shower is in use. Because of this feature, a backflow prevention device is not required for the attachment of this unit to the shower. Additionally, since the unit continually drips while the shower is being used, it is self cleaning. The continuous trickle assists in the continuous cleaning of the unit. The diverter is designed such that when water is diverted to the handle the water continues to flow to the showerhead.
[0025] Also show in FIG. 1 is a hook member 26 which is attachable to the wall of the shower, so that the hose may be advantageously hung therefrom when the unit is not in use. Further, a handle receiving hanger 28 may be provided, wherein the handle may be placed in the hanger for storage when not in use. The hanger 28 suitably has a U-shape and forms an open trough which the handle fits into. A wall mounted soap holder may be employed for this purpose. In the illustrated embodiment, the hanger 28 attaches to the shower wall via suction cups.
[0026] The device may be sold as a kit, including substantially all the components shown in FIG. 1, plus an amount of PTFE thread sealing tape, also known as “plumbers tape”. In more detailed steps of how to install the device, when sold in a kit form, the existing shower head is removed, and the threads on the shower are then cleaned to remove any dirt or debris. Then, the threads are wrapped with several revolutions of the PTFE thread sealing tape in a clockwise direction. Portion 18 is then threaded onto the shower head arm. The suction cups of the hanger 28 and hook member 26 are then wetted and those two items may be attached to the wall of the shower on a flat area, by firmly pressing them against the shower wall. Next, the threads 20 of the diverter are wrapped with several revolutions of the PTFE thread sealing tape, and the shower head is attached thereto.
[0027] [0027]FIG. 5 is a perspective view of a shower head 34 with the diverter 36 installed, illustrating hose 38 . FIG. 6 is a side view illustrating a user holding the handle 10 , showing an exemplary flow 32 of water. FIG. 7 is a view of a shower wall with the device hung thereon by use of the hook 26 and hanger 28 , when in a not-in-use mode. A suitable position relative to the hot/cold water faucets 40 is as shown in FIG. 7, with the device hanging above the faucets. However, this is not a requirement, and different mounting locations are possible, and may be desirable, especially in the case where the faucets are mounted higher on the wall, for example, or in the case of a single centrally mounted hot/cold water control.
[0028] Accordingly, an improved shower bidet/douche is provided which enables easy use thereof, while not requiring installation of backflow prevention valves.
[0029] While a preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. | A shower mounted douche/bidet apparatus employs a diverter and an angled handle member with a dispenser head thereon. The handle is a ball headed arm member which provided an ergonomic spray dispensing. | 4 |
TECHNICAL FIELD
This invention relates to imaging devices, and more specifically, to an optimized illumination system having particular application in 2-D imaging systems.
BACKGROUND OF THE INVENTION
2-D imaging systems typically involve an illumination means and an imaging array, such as Complimentary Metal on Silicon (“CMOS”) or a Charge Coupled Device (“CCD”). Such systems use LEDs or other means to illuminate the object to be captured, and the light reflected from such object is then incident upon the imaging matrix. One problem associated with such devices is that the depth of field over which the illumination of the object can be kept constant is relatively narrow. For example, FIG. 1 shows how the intensity of illumination falls off drastically as a function of distance from the source.
In the prior art, solutions to this problem typically involve installing an additional one or more LEDs or other illumination means, which is directed to the area close to the device. One such arrangement is disclosed in U.S. Published Application No. 2006-0219792. In the '792 publication, two modes of operation are used, each of which has its own associated set of LEDs. Depending upon whether it is desired to capture images in the near field or far field, a different mode of operation is selected, which results in a different set of LEDs being illuminated. However, the position of the various LEDs, renders this arrangement somewhat less than optimal.
Another prior art arrangement with a separate set of LEDs to illuminate an area close to the imaging array is disclosed in U.S. Published Application No. 2006-0118627. As depicted in FIGS. 2A and 2B of the present application, which are taken from the referenced publication, showing a device having a housing 20 , folding mirror 44 , two illumination systems 42 A and 42 B, and imager 40 . Illumination system 42 A includes a plurality of LEDs exteriorly arranged on housing 20 around window 18 . Each exterior LED projects light over a conical volume, shown as region 56 A and 56 B. The second illumination system 42 B includes one or more LEDs disposed in housing 20 remote from window 18 . The LEDs of system 42 B project light over conical volume 58 . In this fashion, system 42 A illuminates a near range field-of-view and system 42 B illuminates a far-range field-of-view, a separate set of LEDs is disposed vertically to the remaining circuit board in the device, and light is directed from these LEDs to illuminate the close in field of view.
These and other prior art arrangements are all suboptimal in that they require arrangements that are either too large in size, too expensive to manufacture, or which are cumbersome to use. Many involve positioning the source of secondary illumination in a manner that increases the manufacturing cost of the device.
Some such prior art arrangements are also less than optimal because the illumination means are positioned in a manner that may shine into a user's eyes. Thus, there exists a need in the art for an improved device that can provide for uniform illumination over a wide range of distances from the imaging array.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the intensity of light over field of view as distance from the imaging array varies, using a prior art system;
FIGS. 2A and 2B show one exemplary prior art arrangement for attempting to uniformly illuminate objects at a close field of view;
FIG. 3 shows a side view from an exemplary embodiment of the present invention;
FIG. 4A is a front view of an exemplary embodiment of the present invention and FIG. 4B depicts the manner in which the location of an LED is referenced with respect to the mask opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The above and other problems with the prior art are overcome in accordance with the present invention which relates to the technique of providing both near field and far field illumination while at the same time avoiding many of the drawbacks of the prior art. Specifically, a plurality of illumination sources such as LEDs are utilized, where each is positioned behind a lens in an offset manner. Because the LED is offset with respect to the lens in front thereof, the illumination can be directed to the far or near fields of view.
FIG. 3 depicts a conceptual side view of an imaging device utilizing the illumination technique of the present invention. The arrangement includes a masking device 306 which partially shields the illumination means 301 and 304 as shown, thereby avoiding the illumination being projected into a user's eyes. An inner portion of the mask is designated 307 . The mask is preferably continuous, as shown in FIG. 4A , and includes an opening surrounding the LED to provide an output path for the light.
As shown best in FIG. 3 , an illumination means 304 is placed behind a lens 305 in an offset manner so that the lens 305 acts to direct the illumination to a far field of view. A similar arrangement is employed and depicted as illumination means 301 with lens 310 . The illumination means 301 and 304 act in concert to provide illumination for the far field of view, also as depicted in FIG. 3 . Further, the illumination means 302 acts to provide illumination for the near field of view.
Although the arrangement provides for a substantially uniform illumination from a near field of view to a far field of view, it is nonetheless still contemplated that a user can select between the near and far field of view, and activate the appropriate illumination means (e.g., LEDs). Or, both can simply be activated when the device is activated for capturing an image.
For example, and with reference to FIG. 4A , a user may select, via a user selectable switch for example, LEDs 301 and 304 to be illuminated, which would illuminate a far field of view, or a user may select LEDs 302 to illuminate when an object is within the near field of view. It is also possible that such selection can occur automatically, and to illuminate the appropriate LEDs, such as by a laser based distance measuring apparatus known in the art.
The LEDs 301 and 304 may be mounted on a circuit board 340 , and other electronics may be on circuit board 350 as well.
Note exemplary LED 304 is aligned with a side of a lens 305 that itself is aligned with an outer mask portion 306 . By placing the LED 304 near to the outer side mask, the beam is directed correctly as shown, and the outer side mask shields the user from having to view the light being emitted by the illumination means 301 and 304 .
FIG. 4A depicts a front view of the imaging device, showing the mask, having inner portion 307 and outer portion 306 (see FIG. 3 ) as well as camera lens 6 and CCD or CMOS sensor 7 and indicating the field-of-view (FOV) of the imaging device. Within the mask are openings 407 through 410 that enable light from the upper LEDs 301 and lower LEDs 304 to properly illuminate the target. Note that each opening 407 - 410 is actually plural openings; that is, in the illustrative embodiment, there are paired openings 407 (i.e., the two upper-right openings in FIG. 4A ), paired openings 408 (i.e., the two upper-left openings), etc. The LED within each opening is closest to a different portion thereof for each of the four sets 407 , 408 , 409 , and 410 of two openings. Specifically, the LED within each opening 409 is closest to a part of the opening that would form an angle of 315 degrees with respect to the horizontal, if the opening represented a Cartesian plane. This measurement scheme is illustrated in FIG. 4B . Within opening 410 , that angle would be 215 degrees. Within opening 407 , that angle would be 135 degrees. And within opening 408 , that angle would be 45 degrees.
The foregoing positioning of the LEDs within the openings results in the illumination of the proper field of view for objects located relatively far from the device. For near field objects, the illuminations means 302 is used, as shown in FIGS. 3 and 4A . These LEDs 302 are optionally not surrounded by mask portions 306 and 307 , but their light is nonetheless advantageously blocked from the user's view by mask portions 306 and 307 . Of course, the entire device may be disposed within a suitable housing, shown only conceptually as 380 for purposes of explanation.
While the foregoing describes the preferred embodiments of the present invention, other variations are possible as well. The imaging array may be comprised of any suitable technology other than CMOS or CCD. The lenses shown may be LED mask lenses, or other types of lenses, and the illumination may be derived from sources other than LEDs. These and other embodiments are intended to be within the scope of the appended claims. | An imaging device preferably for use in a 2-D CCD or CMOS sensor is disclosed. The illumination means uses a plurality of illumination sources, some of which are coupled to lenses in an offset manner to promote far field illumination, and some of which are not so coupled and are arranged to provide near field illumination. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to carburetors for two cycle engines, and more particularly to a carburetor and air-valve assembly and linkage.
Two-cycle engines are desirable for handheld tools where weight is critical because of their high power to weight ratio as compared to four-cycle engines. However, trapping efficiency of conventional two-cycle engines will not meet the low emissions requirements set forth by government regulations in the future because the fundamental design of the two-cycle engine results in too much unburned fuel being discharged into the atmosphere.
The discharge of raw, unburned fuel into the atmosphere is substantially caused by the exhaust and transfer ports being opened and closed by the piston, and for a small period both are open simultaneously during the piston travel. During that small duration of time, when both the intake and exhaust ports are open, the unburned fuel can exit the engine, which increases the measured emissions output of the engine while decreasing the engine's efficiency.
SUMMARY OF THE INVENTION
The present invention provides a carburetor and air valve assembly for a two-cycle internal combustion engine with stratified air scavenging, the assembly comprising: a housing assembly; an intake channel in the housing assembly for delivering fuel and air mixture to an intake port of the engine; a throttle valve disposed within the intake channel and fixed to a pivotable throttle valve shaft; a throttle lever fixed to the throttle valve shaft; an air channel in the housing assembly for delivering fuel-free air to an airport of the engine; an air valve disposed within the air channel and fixed to a pivotable air valve shaft; an air valve lever fixed to the air valve shaft, and an activating lever moveably mounted to the housing assembly and adapted to transmit movement of the throttle lever to the air valve lever.
According to another aspect, the present invention provides a two-cycle internal combustion engine system comprising: a carburetor comprising an intake channel, a choke valve in the intake channel fixed to a pivotable choke valve shaft and a throttle valve in the intake channel fixed to a pivotable throttle valve shaft; an air channel in communication with fresh air and comprising an air valve fixed to a pivotable air valve shaft; a cylinder; a combustion chamber within the cylinder; a fuel port communicating the intake channel with the cylinder; an air port communicating the air channel with the cylinder; a piston arranged for reciprocating movement within the cylinder and comprising a transfer port for intermittently connecting the fuel port and air port with the combustion chamber; a throttle lever fixed to the throttle valve shaft; an air valve lever fixed to the air valve shaft; an activating lever pivotably mounted to the air valve shaft and adapted to transmit movement of the throttle lever to the air valve lever after a predetermined angle of rotation of the throttle lever; a choke valve lever fixed to the choke valve shaft; and a fast idle latch engagable by the choke valve lever to hold the throttle lever in a fast idle position until the throttle lever is separately moved.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a front view of a carburetor and air-valve assembly according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view of the carburetor and air-valve assembly of FIG. 1 in which the valve positions are shown in an idle mode of operation;
FIG. 3 is a cross-sectional view of a second embodiment of a carburetor and air-valve assembly according to the present invention;
FIG. 4 is a cross-sectional view of a third embodiment of a carburetor and air-valve assembly according to the present invention,
FIG. 5 is a cross-sectional view of a fourth embodiment of a carburetor and air-valve assembly according to the present invention;
FIG. 6 is a left side view of the carburetor and air-valve assembly of FIG. 1;
FIG. 7 is a rear view of the carburetor and air-valve assembly of FIG. 1 showing a throttle trigger attached thereto;
FIG. 8 is a right side view of the carburetor and air-valve assembly of FIG. 1;
FIG. 9 is a cross-sectional view of the carburetor and air-valve assembly of FIG. 1 taken along section line 9 — 9 ;
FIG. 10 is a view of the carburetor and air-valve assembly of FIG. 1 taken in the direction of line B—B in FIG. 6, including a choke knob attached thereto;
FIG. 11 is the same view as FIG. 10 but showing the throttle lever rotated until it first starts to open the air valve;
FIG. 12 is the same view as FIG. 10 but showing the throttle lever at full open position and the air valve also is rotated to its full open position;
FIG. 13 is the same view as FIG. 10 but showing the throttle lever in a fast idle position, and the choke knob pulled out to a full choke position;
FIG. 14 is the same view as FIG. 13 but showing the choke pushed in to it's normally open position, and the fast idle still activated;
FIG. 15 is a view of the carburetor and air-valve assembly according to a third embodiment of the invention, corresponding to the view of FIG. 10, including an adjustment screw;
FIG. 16 is a view of the carburetor and air-valve assembly according to a fourth embodiment of the invention, corresponding to the view of FIG. 10;
FIG. 17 is a view of the embodiment of FIG. 17 with the levers rotated to a full throttle position;
FIG. 18 is a chart depicting the relationship between the air and throttle valve progression from fully closed through fully open according to the present invention;
FIG. 19 is a cross sectional view of the carburetor and air valve assembly of FIG. 1 taken along section line 19 — 19 , including an engine cylinder; and
FIG. 20 is a cross sectional of a carburetor and air valve assembly, corresponding to FIG. 1, according to a sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a first embodiment of a carburetor and air valve assembly 10 is shown in FIGS. 1, 2 , 6 - 15 , 18 and 19 . Referring to FIG. 2, a carburetor 12 serves for supplying fuel and air mixture to an internal combustion engine 14 . The carburetor 12 is a diaphragm-type carburetor 12 for an internal combustion engine 14 that operates with stratified air scavenging, specifically but not limited to hand held power equipment, such as chain saws, string trimmers, brush cutters, pole saws, or the like. The carburetor 12 comprises a carburetor housing 16 in which is formed a continuous intake channel portion 18 having a venturi section 20 . The carburetor has two independent butterfly valves within the intake channel 18 . The first valve is called the choke valve 22 , and when closed it restricts the air opening to enrich the fuel-air ratio for improved cold starting performance. The second valve inside the carburetor 12 is the throttle valve 24 , which varies the amount and flow of the fuel-air mixture, which in turn controls the engine speed.
The throttle valve 24 is located down stream from the venturi section 20 . The throttle valve 24 is pivotally held via a shaft 26 that is mounted in the carburetor housing 16 . A main fuel-delivery duct 28 opens into the venturi section 20 . Fuel-delivery idle ducts (not shown) open into the intake channel portion 18 in the vicinity of the throttle valve 24 . The channels and ducts are supplied fuel from the fuel-filled control chamber (not shown) from within the carburetor housing 16 , which are in turn supplied via fuel line from a fuel tank (not shown). The fuel is pumped to the carburetor 12 via a fuel pump powered by fluctuating crankcase pressure from the two-cycle engine 14 .
In addition to the intake channel portion 18 , by means of which a fuel/air mixture is supplied to the internal combustion engine 14 , an air channel 30 is provided and has an air butterfly valve 32 mounted on a pivotable shaft 34 . The air channel 30 acts as a bypass to the intake channel portion 18 and connects a clean air side of an air filter housing 36 with an air port 38 in the cylinder 40 . By way of the linkage described below, the two separate valves 24 , 32 are timed and orientated specifically to obtain peak performance of the engine in the forms of horsepower and emissions.
As best seem from FIG. 9, the shaft 26 of the throttle valve 24 and the shaft 34 of the air valve 32 are disposed approximately parallel to one another. Alternatively, the throttle valve shaft 26 may be disposed at an angle relative to the air valve shaft 34 according to the present invention.
The carburetor 12 is responsible for delivering a blend of fuel and air to the engine 14 , which is drawn into the crankcase through a fuel port 42 on the side of the cylinder 40 . This cylinder fuel port 42 is opened and closed by the piston 44 pivotally connected to the crankshaft that rotates horizontally in the crankcase and is supported by bearings. The carburetor 12 is constructed similarly to that of a conventional two-cycle engine, but with a slightly smaller venturi 20 size to compensate for the air channel 30 . The combined cross-sectional areas of the air channel 30 and intake channel 18 of the carburetor 12 are similar to that of a standard two-cycle engine. Once the fuel/air enters the crankcase it is fed to the combustion chamber by transfer ports 46 , 48 , which are also opened and closed by the piston's 44 travel up and down the cylinder bore. These ports 46 , 48 opening and closing are timed to achieve maximum performance.
The air channel 30 and air valve 32 are responsible for delivering fresh air to the top of the transfer ports 46 , 48 in order to help improve the emissions characteristic of the two-cycle engine 14 . This stratified air scavenging engine concept is designed to reduce the amount of unburned fuel that leaves the combustion chamber when the exhaust port is open. This is achieved by dispersing the fresh air from the air channel 30 into the combustion chamber first when the exhaust port is open, and scavenging the exhausted fuel with the fresh air. Immediately following the fresh air charge is the fuel-air mixture that is delivered from the crankcase through the transfer ports 46 , 48 into the combustion chamber. By separating the fresh air and the fuel-air mixture in such a stratified fashion to reduce the unburnt fuel discharged from the exhaust port, engine emissions are reduced and engine efficiency is increased.
In the first embodiment, shown in FIG. 2, the air channel 30 is formed by a separate air valve housing 50 , which is trapped between the carburetor housing 16 and the air filter housing 36 . Carburetor mounting screws 52 are used to secure the air valve housing 32 and the air filter housing 36 to an intake adaptor 54 . The air channel 30 is transversely connected to the intake adaptor 54 by a flexible rubber tube 56 . The rubber tube 56 forms an airtight seal at its ends 58 , 60 on each of the air valve housing 32 and intake adaptor 54 , respectively. Alternately the air channel 30 could be formed by a rigid material instead of the rubber tube 56 described.
The intake adaptor 54 provides heat insulation between the engine 14 and the carburetor 12 and the air inlet 30 . Excessive heat on the carburetor 12 from the engine 14 will vaporize the gasoline prematurely and cause what is commonly known as “vapor lock.” If this occurs, not enough fuel enters the engine 14 and the engine 14 will not function.
Both the air channel 30 and the intake channel 18 are connected to the air filter housing 36 which contains a filter element. The filter element traps and prevents dirt, dust and other particles from entering the engine 14 , which would cause internal damage to the engine components. The air channel 30 is connected to a clean air chamber 62 of the air filter housing 36 to the intake adaptor 54 , which feeds the cylinder air port 38 . The clean air chamber 62 inside the air filter housing 36 may be a single chamber or may alternately be separated into individual and separate areas by a divider wall 64 formed in the air filter housing 36 .
According to a second embodiment, as shown in FIG. 3, the air valve 32 and a pivotable air valve shaft 34 are secured within an alternative air filter housing 36 ′ which would eliminate the air valve housing 50 of the first embodiment.
According to a third embodiment, as shown in FIG. 4, similar to that in FIG. 3, a straight tube 56 ′ could be used by extending a second alternative filter housing 36 ′ out and downward.
According to a fourth embodiment, as shown in FIG. 5, the intake adapter 54 ′ is formed of two pieces, a first intake adapter portion 54 a ′ and a second intake adapter portion 54 b ′. The second intake adapter portion 54 b ′ has an angular offset which allows the use of a straight tube 56 ″ to connect to the filter housing 36 ′, rather than the curved tube 56 of the first and second embodiments. Further, the two piece intake adapter 54 ′ may be formed through conventional casting methods since each portion 54 a ′, 54 b ′ does not contain any compound curves.
Referring again to the first embodiment shown in FIGS. 1, 2 , 6 - 15 , 18 and 19 , a linkage mechanism described hereinafter functionally connects the throttle valve 24 and air valve 32 . Additional linkage also allows for a choke operation during cold starting, and a fast idle setting for starting. This is achieved with several levers that all work together to rotate the butterfly valves into ideal positions for different modes of operation.
The air valve 32 must cooperate with the throttle valve 24 in the carburetor 12 since both valve 24 , 32 are responsible for governing the amount of fuel-air mixture that is delivered to the engine 14 . The air valve 32 must also remain closed during slow engine speeds, like starting and idling, or the engine 14 will stall because the mixture goes too lean (not enough fuel to produce combustion). The linkage mechanism describe hereinafter is designed to not open the air valve until the throttle valve 24 has rotated approximately 30 degrees from its normally closed position. This angle can be adjusted as appropriate for a particular application. Referring to FIG. 18, once the air valve 32 starts to open, its progression to a fully open position is non-linear, and does not have the same opening rate as the throttle valve 24 . The different slopes between the throttle valve 24 and air valve 32 allow for optimization of performance for mid-range power and acceleration. Thus progression can be modified by use of cam shapes on the lever or lobe-shaped slider pin. The opening of the air valve 32 is opened slowly, so to not drown the engine with too much fresh air. Once the throttle valve 24 has achieved approximately 86% full open, the air valve 32 has less affect, and therefore can complete it's progression to full open at an accelerated rate.
As best shown in FIGS. 7 and 9, a first end 66 of the throttle valve shaft 26 carries a throttle valve actuating lever 68 that is connected with a throttle trigger 70 by means of a wire or cable 72 for adjusting the throttle valve 24 . In particular, the actuating lever 68 is fixedly disposed at the first end 66 of the butterfly valve shaft 26 and is spring loaded in the closing direction of the throttle valve 24 by means of a return spring 74 .
A second end 76 of the throttle valve shaft 26 projects out of the carburetor housing 16 and fixedly carries a throttle lever 78 . On opposite ends of the throttle valve shaft 26 , the actuating lever 68 and the throttle lever 78 both being fixedly fastened to the throttle valve shaft 26 rotate together. The air valve shaft 34 carries an air valve lever 80 , which is fixedly disposed at an end 82 of the air valve shaft 34 , and is spring loaded in the closing direction of the air valve 32 by means of an air valve return spring 84 . An activating lever 86 is pivotally mounted on the air valve shaft 34 , but is not fixed to the air valve shaft 34 , and therefore is free to rotate about the air valve shaft 34 . The activating lever 86 is spring loaded in the closing direction of the air valve 32 by means of a return spring 88 . The activating lever 86 has a protruding member 90 that will contact the air valve lever 80 on the air valve shaft 34 at a specific point during it's rotation, at an angle of engagement 92 as shown in FIG. 12 . This angle of engagement 92 corresponds to the angle that the throttle valve 24 must rotate before the air valve 32 starts to move and is a functional aspect of the two-stroke engine's acceleration performance. The nominal measure of the angle of engagement 92 is approximately 30 degrees, but can be varied to obtain different acceleration properties.
An alternative design according to a third embodiment of the present invention is shown in FIG. 15 which includes an adjustment screw 94 is shown fastened into the activating lever 86 and the end of the adjustment screw 94 contacts the air valve lever 80 . By turning the adjustment screw 94 in and out it will effectively change the angle of engagement 92 from the nominal 30-degree angle. This adjustment will allow for manufacturing to accommodate for variances that occur because of normal manufacturing tolerances.
As shown in FIG. 10, the activating lever 86 has a protruding boss 96 , which intersects the path of the throttle lever 78 and forms a transmission connection between the throttle valve 24 and air valve 32 (see FIG. 9) The boss 96 slides along the throttle lever 78 for the entire range of angular rotation 98 of the throttle valve shaft 26 to fully open the throttle valve 24 as shown in FIG. 12 . During the angle of rotation 98 of the throttle valve 24 the activating lever 86 will progress through its angular range of rotation 100 until the air valve shaft 34 has also achieve full open position for the air valve 32 . The progression of the throttle valve 24 opening in respect to the air valve 32 will have an affect on the acceleration of the two-stroke engine's performance. Both the throttle valve 24 and the air valve 32 by design will open fully at the end of the rotational travel 98 and 100 , but the rate of opening maybe different. FIG. 18 shows an example of the rate of opening of the throttle valve 24 and the air valve 32 .
An alternate design according to a fourth embodiment of the present invention is shown in FIG. 16 & FIG. 17 . The pivotally mounted activating lever 86 is replaced with a fixed activating lever 102 . The fixed activating lever 102 is positively connected to the end of the air valve shaft 34 and the air valve lever 80 so that they rotate together. There is an intentional clearance 104 between the throttle lever 78 and a protruding boss 106 on the activating lever 102 . The clearance 104 allows for the throttle valve 24 to open 30 degrees of rotation while the air valve 32 remains closed. After the initial 30 degrees of travel of the throttle lever 86 , the throttle lever 86 will contact the protruding boss 106 on the activating lever 102 and start rotating the air valve 32 in the opening direction. Both the throttle valve 24 and the air valve 32 will reach full open position at the same time, but not at the same rate, similar to FIG. 18 . The throttle valve 24 and, air valve 32 are shown in FIG. 17 at their respective full open positions with the levers 78 , 80 at their full limits of travel 108 and 110 .
As shown in FIG. 18 the slope and intersection points of the curves can be arranged and changed with change in pivot positions of the two butterfly valve shafts 34 , 26 in respect to each other, and in respect to the contact point of the protruding boss 96 or 106 , along with the angle of engagement 92 of first contact between the activating lever 86 and air valve lever 80 . Even the physical shape of the contact boss 96 can be changed from a true circle cross section to one of an elliptical shape, cam profile, or other shape. A contact surface 112 of the throttle lever 78 can also be formed with a curved profile to achieve a similar change in the curves shown in FIG. 18 .
Starting from idle position shown in FIG. 10 and FIG. 2, the throttle valve 24 is opened by pivoting the throttle valve shaft 26 in an opening direction 114 , so that greater quantity of fuel-air mixture is conveyed to the internal combustion engine 14 so that the speed of the internal combustion engine increases. As soon as the throttle valve 24 , i.e. the throttle valve shaft 26 , in the opening direction 114 has transmittally rotated the activating lever 86 through a free play extent to the angle of engagement 92 that is determined by the spacing between the protruding member 90 on the activating lever 86 and the air valve lever 80 , then by means of rotational force i.e. torque, the air valve lever 80 is also pivoted in an opening direction 116 , as a result of which by means of the shaft 34 the air valve 32 in the air channel 30 is carried along in the opening direction 116 . In addition to the fuel-air mixture, air for combustion by itself, which is expediently collected previously in the transfer ports 46 , 48 from the crankcase to the combustion chamber, is conveyed to the internal combustion engine via the air channel 30 . For this purpose, as shown in FIG. 19, a branch element 118 is formed by the piston casting 44 ; the branching air supply channels 120 and 122 formed in the piston casting 44 open into the corresponding transfer ports 46 and 48 .
An alternate design according to a sixth embodiment of the present invention is shown in FIG. 20, where an alternative air channel 30 ′ branch element 142 is located upstream from the piston 44 , which has separate air channels 120 and 122 formed in an alternative piston casting 44 ′. The branch element can be formed within the casting of the cylinder 40 , or within the intake adaptor 54 , or within the air tube 56 , or any combination thereof.
Along with the mechanical transmission between the air valve and the throttle valve there is another mechanism that allows for easier starting of the two-cycle engine. A “fast idle” portion of the linkage mechanism mounted on the carburetor 12 is designed to manually advance the throttle valve 24 position approximately 20 degrees for starting of the engine 14 . Of course, this angle can be adjusted as appropriate for a particular application. This throttle advance allows for easier starting of the engine 14 since there will be more fuel allowed to enter the engine than would be allowed at the normally closed or idle position. A fast idle lever 124 is rotated when a choke knob 126 is pulled by the operator, which in turn rotates the choke valve 22 . The fast idle lever 124 is pivoted to a choke valve shaft 128 such that it is free to rotate about the choke valve shaft 128 . When the choke knob 126 is pulled, a choke valve lever 130 catches the fast idle lever 124 and rotates it which in turn lifts the throttle valve lever 78 into the “fast idle position.” The two levers 78 , 124 are held in place by a small catch or notch 138 formed into the throttle lever 78 . The choke knob 126 can be pushed back in to open the choke valve 22 without affecting the fast idle advance because the fast idle lever 124 turns freely on the choke valve shaft 128 . Small torsion springs are located on both valve shafts 26 , choke valve shaft 128 to provide positive return force to their normal positions.
As shown in FIG. 13 pulling the choke knob 126 out to a limit of linear travel 134 , which is nominally 10 mm, will transversely rotate the choke valve shaft 128 for an angle of rotation 132 . The end of the choke knob 126 is pivotally connected to the choke lever 130 . The choke lever 130 is fixed to the end of the choke valve shaft 128 and has a butterfly valve 22 affixed to the choke valve shaft 128 . The choke valve shaft 128 is pivotally mounted in the carburetor housing 16 and when closed will enrich the fuel to air ratio for easier cold starting of the two-cycle engine 14 . The choke lever 130 when rotated will contact a fast idle latch or lever 124 . The fast idle lever 124 is pivotally mounted on the choke valve shaft 128 and is free to rotate about that axis. When the fast idle lever 124 is rotated by the choke lever 130 through it angle of rotation 132 it contacts the throttle lever 78 and rotates the throttle lever 78 for an angle of rotation 136 to a fast idle position. In this embodiment, the angle of rotation 136 is approximately 20 degrees open from its at rest, closed position and allows the throttle valve 24 to be positioned for optimum starting of the two-cycle engine. The throttle lever 78 is held in the starting position by a small notch 138 (FIG. 12) formed in the throttle lever 78 which the fast idle lever 124 engages.
Often when starting a two-cycle engine it is necessary to repeatedly open and close the choke valve. During this process, the throttle lever 78 it is kept in the fast idle position by the fast idle lever 124 as shown in FIG. 14 . The choke knob 126 can be pushed back-in the limit of travel 134 to open the choke butterfly valve 22 by means of the transmission connection. The fast idle lever 124 will remain engaged in the notch 138 in the throttle lever 78 , and the throttle lever 78 will stay at the rotated angle 136 or the fast idle position. This is achieved because the fast idle lever 124 is freely pivot about the choke valve shaft 128 . A return spring 140 as shown in FIG. 6 is connected to the fast idle lever 124 and the carburetor housing 16 . The return spring 140 acts upon the fast idle lever 124 in a counterclockwise direction (opposite direction 114 ), which will disengage the first idle lever 124 from the throttle lever 78 . Thus, the fast idle lever 124 can be returned to the normal at-rest position by activating the throttle trigger 70 which is connected to the throttle lever 78 . When the throttle lever 78 is rotated open, the fast idle lever 124 is released by the notch 138 in the throttle lever 78 allowing the return spring 140 to rotate the fast idle lever 124 back to the normal at-rest position.
Although the described embodiments related to a piston ported two-cycle engine with stratified air scavenging, meaning the piston 44 opened and closed the air port 38 during the normal piston stroke in the cylinder 40 , the present invention can be equally utilized on a two-cycle engine with stratified air scavenging with a reed style check valve mounted in the transfer ports 46 , 48 .
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A carbureted two-cycle engine including an intake channel, a choke valve in the intake channel fixed to a pivotable choke valve shaft and lever, and a throttle valve in the intake channel fixed to a pivotable throttle valve shaft and lever. The engine includes an air channel in communication with fresh air, and an air valve fixed to a pivotable air valve shaft and lever. A piston within a cylinder of the engine includes a transfer port for intermittently connecting the intake channel and the air channel with a combustion chamber. An activating lever pivotably mounted to the air valve shaft transmits movement of the throttle lever to the air valve lever after a predetermined angle of rotation of the throttle lever. A fast idle latch is engagable by the choke lever to hold the throttle lever in a fast idle position until the throttle lever is separately moved. | 8 |
FIELD OF THE INVENTION
This invention relates generally to detection of organisms by gene sequence polymorphisms. More specifically, this invention relates to the detection of drug resistance, and differentiation of very closely related microorganisms by detection of novel polymorphisms in topoisomerase gene loci.
BACKGROUND OF THE INVENTION
Pathogenic strains of E. coli are a common target for identification in clinical settings. For example, E. coli O157:H7 is a pathogenic bacterium that causes severe diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (Nataro and Kaper 1988, Whittam 1993). Rapid identification of E. coli O157:H7, other shiga toxin producing E. coli (“STEC”), other entero-pathogenic E. coli (e.g., O26:H11) and nonpathogenic E. coli is critical for proper treatment and control of epidemics (McDonald and Osterholm, 1993, Majkowski, 1997).
Additionally, in connection with identifying such bacteria, there is also interest in discovering which drugs are effective against such microorganisms so that a treatment regimen can be initiated. Many of the current methods that are used to diagnose pathogenic and drug resistant strains of bacteria require the isolation of the suspect sample from bacterial monocultures that must be incubated over a number of days only after which the pathogenic strain can be identified by performance of biochemical tests. (see review in Swaminathan 1994). Such tests include phage typing, sorbitol fermentation, beta-glucuronidase production, protein identification by immunological means, colony hybridization with DNA probes, and restriction fragment length polymorphism (“RFLP”) analysis.
Assays incorporating nucleic acid amplification have the potential to lower the costs and shorten considerably the assay time due to the increased organism-specific sensitivity and the ability to identify particular organisms (genera and strains) directly from mixed culture samples. Such shortening of time and lowering of costs will allow patient samples to be tested for the identification of specific pathogenic strains on a routine basis in contrast to the current practice of testing for such organisms on an “as needed” basis.
Numerous nucleic acid based methodologies have been devised for microorganism identification including the use of DNA amplification (see Arbeit 1995, Whelen and Pershing 1996). One method, the random amplification of polymorphic DNA, (“RAPD”), uses a single random primer in a polymerase chain reaction (“PCR”) to obtain a fingerprint of random amplification products. The RAPD technique suffers from the need to establish monocultures prior to strain detection and identification. Moreover, the RAPD technique requires the skill of a technician trained to interpret a complex pattern of bands generated by the technique.
Another method targets regions of nucleotide sequence that encode, or are related to the production of, a pathogen's toxin. For example, specific gene loci for shiga toxins, such as slt-I, and slt-II afford the ability to distinguish E. coli O157:H7 from strains of non-toxin producing pathogens. However, the use of toxin specific loci are limited because testing is only applicable to a narrow range of microbial species that encode the specific toxin being tested.
Another bacterial identification system uses 16S-ribosomal RNA (Weisberg et al. 1991, Neefs et al. 1993). The 16S system is less than desirable because multiple copies of the rRNA gene may contain multiple polymorphisms (a situation known as heteroplasmy) making identification of a specific bacterial strain difficult. Additionally, while the system is able to separate unknown bacteria to the species level, it is not possible to differentiate subspecies strains.
Still other methods which use genetic sequences in hybridization oriented identification are documented. In particular, a method of identifying microorganisms using polymorphisms within the type II DNA topoisomerase genes has been disclosed ( Annu. Rev. Genet., 1996, Vol. 30, pp 79–107, by W. M. Huang, Antimicrobial Agents and Chemotherapy , September 1995, Vol. 39, No. 9, pp 2145–2149, by I. Guillemin et al., U.S. Pat. No. 5,645,994, by W. M. Huang, all of which are herein incorporated by reference).
Prokaryotic and eukaryotic type II topoisomerases are related in their structure and function. These molecules are essential for maintenance of DNA superhelicity for DNA replication. One type II topoisomerase from bacteria is DNA gyrase. Bacterial DNA Gyrase is composed of two subunits, GyrA and GyrB. The amino acid sequence of the GyrA subunit is highly conserved between prokaryotic and eukaryotic organisms. However, at the DNA level codon usage and G-C content are markedly divergent. The divergence in the nucleic acid sequences has provided the basis for the development of rapid methodology to identify new bacterial topoisomerase genes (see W. M. Huang 1996).
Comparison of a variety of prokaryotic Gyrase A genes shows that the length of the protein encoded by such genes is in the range of 850 amino acids. The overall identity among GyrA proteins from these different organisms is only about 40% with the greatest variability occurring in the C-terminal third of the sequences. However, the N-terminal portion of the genes are highly conserved, which conservation allows the grouping of the various species in a manner consistent with the grouping elucidated using rRNA sequence analysis. (see Neef, 1993, and Olsen, 1994).
The known GyrB subunit gene sequences encode proteins of between 650 and 800 amino acids in length. In general, the GyrB proteins from various organisms tested share approximately 60% overall amino acid sequence identity.
A second type II topoisomerase gene known in E. coli has sequence identity with the GryA. Specifically, the parC gene has 36% identity with and is generally shorter than the GryA gene encoding a protein of about 750 amino acids.
Alignment of type II topoisomerase genes from a variety of organisms has revealed that the N-terminal region is highly conserved at the amino acid level such that there are at least nine regions having at least five invariant amino acids interspersed with more variable regions. The consensus regions provide DNA sequences that are useful for designing “universal” primers for the amplification of intervening variable regions. The availability of nucleic acid sequences of the intervening variable regions has allowed identification of new topoisomerase genes in such organisms and consequently the ability to study biodiversity at the species level.
For example, U.S. Pat. No. 5,645,994 by W. M. Huang discloses a method of identifying species of bacteria by amplifying variable or “signature” sequences that are interspersed between the conserved sequences. The flanking conserved sequences are used to design universal primers for amplification of the signature sequences. Following amplification, the signature sequences are cloned and sequenced and the sequence is compared against a database of signature sequences from multiple species. Likewise, Huang discloses that alignment of the DNA sequences from isolates of one genus can be used to examine micro-diversity among species of a genus.
The current invention provides numerous polymorphisms recently discovered in the GyrA, GyrB, and parC subunits of topoisomerase type II genes that have application in the detection and identification of subspecies of pathogenic and nonpathogenic bacteria. The current invention also provides polymorphisms identified in the type II isomerases that are associated with drug resistance wherein the proteins and regulation of the genes in which the polymorphisms are found are not affected by or biochemically associated with the function of the drug.
For example, with regard to drug resistance, outbreaks of drug resistant strains of Staphylococcus aureus occur periodically in clinical environments such as in hospitals where there may be concentrations of patients suffering from compromised immune systems (Herwaldt and Wenzel 1995). Rapid identification of such resistant strains is recognized as being crucial for the adoption of appropriate treatment regimens (Morita 1993). Most important in such resistance outbreaks has been resistance to methicillin. With respect to methicillin resistance, a gene locus frequently responsible for such resistance is the mecA locus (see Archer and Neimeyer 1994) which has been, along with surrounding noncoding regions, the target of amplification-based assays (e.g., Murakami et al. 1991). While the mecA gene provides a direct link to methicillin resistance, the locus is specific to the genus Staphylococcus and thus is of limited utility as a general diagnostic because only drug resistant Staphylococcus aureus should be identified. Moreover, because mecA DNA is susceptible to horizontal transfer between bacteria, (Archer and Niemeyer 1994, Wu et al. 1996), the potential for misidentification exists causing serious drawbacks to the use of mecA as an identification marker for pathogenic S. aureus.
In contrast, topoisomerase type II polymorphisms have been used to identify drug resistance in microorganisms. Specifically, the Gryase A gene has been used to study resistance of certain bacterial strains to fluoroquinolone (“FQ”) antibiotics. (e.g., Mycobacterium sp. Guillemin 1995, Campylobacter sp. and Helicobacter sp. Husmann 1997, and Staphylococcus aureus Wang 1998). Biochemically, FQ resistance functions because the mutation in the GyrA protein sequence interferes with the ability of the antibiotic to interact with GyrA/DNA complexes resulting in continued growth and division of the replicating organism. It has been observed that the mutations responsible for FQ resistance are clustered within a small pocket of amino acids in the N-terminal portion of the protein. Since the biochemistry and the genetics of the GyrA gene suggest the involvement of a small number of amino acids, the amino acids at these positions can be correlated with the general antibiotic susceptibility of these bacteria. Thus, as suggested by Guillemin, a screening method may be developed to identify species having resistance to FQ antibiotics based on the mutations in the Gyrase A gene.
Of greater significance, we have discovered polymorphisms in the Gyrase A gene that are associated with non-FQ antibiotics drug resistance that is not involved in or associated with the functionality of topoisomerase:DNA complexes. This discovery is very important because it indicates that polymorphisms in the GyrA subunit are indicative of subtle but distinct differences between organisms where there is no known evolutionary pressure that would assist an organism in developing such genetic divergence.
Although the prior disclosures are directed to the use of Gyrase A gene polymorphisms in the identification of species of organisms and at least one class of antibiotic resistance, such prior disclosures have failed to recognize or disclose a recognizable association between topoisomerase type II sequence polymorphisms and significant divergence between very closely related organisms. For example, pathogenic strains of E. coli that have been isolated and classified as strain 0157:H7 have been found to include numerous polymorphisms. Thus, it is questionable whether classifying such isolates as only one strain (i.e. 0157:H7) is satisfactory. Likewise, it has been found that E. coli strain K12, which has traditionally been attributed to be the same strain as wild type E. coli ATCC 11775, is divergent from the wild type strain and is actually a separate “laboratory” strain as indicated by divergence in the Gyrase A gene. (see below)
The current invention recognizes the importance of these subtle divergences within the GyrA, GyrB, and parC proteins of the topoisomerase family and provides numerous polymorphisms useful for the identification of closely related organisms that may be heretofore unrecognized subspecies variations within populations of organisms that have traditionally been classified together as a single species.
SUMMARY OF THE INVENTION
The current invention provides numerous polymorphisms in the topoisomerase type II loci gyrA, gyrB, and parC, that have been identified in a variety of microorganisms and that are useful as identification markers for distinguishing pathogenic from non-pathogenic as well as drug resistant from non-drug resistant organisms. In one embodiment of the invention, point mutations are disclosed within a 100 base-pair N-terminal fragment of the Gyrase A gene.
In a preferred embodiment one point mutation for a set of organisms (e.g., E. coli strains 0157:H7, 055:K59(B5):H—) may be found within a 91 base-pair fragment of the GyrA gene which begins at codon 69 and ends at codon 99. More specifically, this point mutation is a guanine to adenine (G to A) substitution in the third position of codon 84.
In another preferred embodiment one point mutation for a set of organisms (e.g., E. coli strains 0157:H7, 055:K59(B5):H—) may be found within a 102 base-pair fragment of the GyrB gene which begins at codon 236 and ends at codon 270. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the third position of codon 251.
In another preferred embodiment one point mutation for a set of organisms (e.g., Shigella boydii ) may be found within a 96 base-pair fragment of the GyrB gene which begins at codon 149 and ends at codon 181. More specifically, this point mutation is a thymine to cytosine (T to C) substitution in the third position of codon 166.
In another preferred embodiment one point mutation for a set of organisms (e.g., Shigella sonnei ) may be found within a 96 base-pair fragment of the GyrB gene which begins at codon 149 and ends at codon 181. More specifically, this point mutation is a guanine to adenine (G to A) substitution in the third position of codon 164.
In another preferred embodiment one point mutation for a set of organisms (e.g., Shigella flexneri ) may be found within a 91 base-pair fragment of the GyrB gene which begins at codon 167 and ends at codon 197. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the third position of codon 181.
In another preferred embodiment one point mutation for a set of organisms (e.g., E. coli strains 0157:H7, 055:K59(B5):H—) may be found within a 91 base-pair fragment of the parC gene which begins at codon 121 and ends at codon 151. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the first position of codon 136.
In another preferred embodiment one point mutation for a set of organisms (e.g., Shigella boydii isolate ATCC 35964) may be found within a 91 base-pair fragment of the parC gene which begins at codon 134 and ends at codon 164. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the third position of codon 149.
In another preferred embodiment one point mutation for a set of organisms (e.g., Shigella flexneri isolate 29903) may be found within a 95 base-pair fragment of the parC gene which begins at codon 185 and ends at codon 216. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the third position of codon 201.
In yet another preferred embodiment one point mutation for a set of organisms having resistance to methicillin, (e.g., Sharp Memorial Hospital Staphylococcus aureus isolates C83, C84, and C87) may be found within a 98 base-pair fragment of the GyrA gene which begins at codon 69 and ends at codon 101. More specifically, this point mutation is a cytosine to thymine (C to T) substitution in the second position of codon 84.
In yet another preferred embodiment one point mutation for a set of organisms having resistance to methicillin, (e.g., Sharp Memorial Hospital Staphylococcus aureus isolates C300, and ATCC 33591) may be found within a 98 base-pair fragment of the GyrA gene which begins at codon 69 and ends at codon 101. More specifically, this point mutation is a thymine to cytosine (T to C) substitution in the third position of codon 86.
In yet another preferred embodiment one point mutation for a set of organisms having resistance to methicillin, (e.g., Sharp Memorial Hospital Staphylococcus aureus isolates C300, and ATCC 33591) may be found within a 91 base-pair fragment of the GyrA gene which begins at codon 112 and ends at codon 142. More specifically, this point mutation is a guanine to adenine (G to A) substitution in the third position of codon 127.
In still another preferred embodiment one point mutation for a set of organisms having resistance to methicillin, (e.g., Sharp Memorial Hospital Staphylococcus aureus isolates C83, C84, and C87) may be found within a 88 base-pair fragment of the GyrA gene which begins at codon 157 and ends at codon 186. More specifically, this point mutation is a thymine to adenine (T to A) substitution in the third position of codon 172.
In still another preferred embodiment one point mutation for a set of organisms having resistance to methicillin, (e.g., Sharp Memorial Hospital Staphylococcus aureus isolates C83, C84, and C87) may be found within a 88 base-pair fragment of the GyrA gene which begins at codon 157 and ends at codon 186. More specifically, this point mutation is a cytosine to adenine (C to A) substitution in the third position of codon 176.
Other preferred embodiments relate to the manner in which the point mutations may be used to identify organisms.
In one embodiment, the mutant sequence may be incorporated into oligonucleotide probes for use in restriction fragment length polymorphism (“RFLP”) analysis.
In another embodiment, probes may be designed which incorporate the mutations for use in strain-specific DNA amplification. In this embodiment, oligomers are designed such that the nucleotide of the point mutation is placed at the 3′ terminal portion of the oligomer. This allows the use of techniques in which amplification will occur only if the point mutation is present in the organism being tested.
In another embodiment, probes incorporating the point mutations are provided for use either as labeled signal probes or as capture probes in conjunction with microelectronic assay formats.
In still another embodiment the identified gene fragments containing the polymorphisms provide nucleic acid sequences for designing oligonucleotide primers for nucleic acid amplification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the relative position (i.e., I) of the 30 nucleic acid fragment containing the polymorphism in the GyrA gene related to identification of pathogenic E. coli strain O157:H7
FIG. 2 is a schematic diagram showing the relative positions of the nucleic acid fragments containing the polymorphisms in the parC gene related to identification of pathogenic E. coli strain O157:H7 (i.e., II); identification of pathogenic Shigella boydii (i.e., III), and identification of pathogenic Shigella flexneri (i.e., IV).
FIG. 3 is a schematic diagram showing the relative positions of the nucleic acid fragments containing the polymorphisms in the GyrA gene related to identification of methicillin resistance in Staphylococcus aureus (i.e., Gyr A sections MRSA I, MRSA II, and MRSA III).
FIG. 4 is an evolutionary lineage diagram indicating that, as indicated by the polymorphisms associated with the pathogenic E. coli strain O157:H7, the O157:H7 strain is an independent evolutionary lineage from Shigella sp. and other E. coli.
FIG. 5 is an evolutionary lineage diagram indicating that, as indicated by the two sets of polymorphisms for S. aureus isolates C83, C84, and C87 versus wild type isolates of S. aureus ATCC 33591 and C300, the polymorphisms may represent speciation events.
FIG. 6 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrA gene showing the location and sequence of each of the polymorphisms in GyrA disclosed herein in for E. coli strains O157H:7, and O55:K59(B5):H— corresponding to I of FIG. 1 . The polymorphism of import is a G to A transition (Seq. Id. No. 1). The figure also denotes two other polymorphisms of a C to T transition which are not associated with pathogenicity. The mutant sequence is compared to wild type E. coli strain K-12 (Seq. Id. No. 27).
FIG. 7 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the parC gene showing the location and sequence of each of the polymorphisms (Seq. Id. No. 2) in parC disclosed herein for E. coli strains O157H:7, and 055:K59(B5):H— corresponding to II of FIG. 2 . The mutant sequence is compared to wild type strain K-12 (Seq. Id. No. 28).
FIG. 8 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the parC gene showing the location and sequence of each of the polymorphisms (Seq. Id. No. 3) in parC disclosed herein for Shigella boydii isolates CDC 2710-54 (ATCC 35964) corresponding to III of FIG. 2 . The mutant sequence is compared to wild type E. coli strain K-12 (Seq. Id. No. 29).
FIG. 9 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the parC gene showing the location and sequence of the polymorphisms (Seq. Id. No. 4) in parC disclosed herein for Shigella flexneri isolate ATCC 29903 corresponding to UV in FIG. 2 . The mutant sequence is compared to wild type E. coli strain K-12 (Seq. Id. No. 30).
FIG. 10 a is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrA gene showing the location and sequence of each of the polymorphisms in the MRSA I section of GyrA disclosed herein for Staphylococcus aureus isolates C83, C84, and C87 (Seq. Id. No. 5); and ATCC 33591 and C300 (Seq. Id. No. 6) which are associated with drug resistance. This sequence corresponds to MSRA I of FIG. 3 . The polymorphic sequence is compared against non-methicillin resistant S. aureus Genebank sequence M86227 (Seq. Id. No. 31).
FIG. 10 b is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrA gene showing the location and sequence of each of the polymorphisms (Seq. Id. No. 7) in the MRSA II section of GyrA disclosed herein for Staphylococcus aureus isolates ATCC 33591, and C300 which are associated with drug resistance. This sequence corresponds to MSRA II of FIG. 3 . The polymorphic sequence is compared against non-methicillin resistant S. aureus Genebank sequence M86227 (Seq. Id. No. 32).
FIG. 10 c is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrA gene showing the location and sequence of each of the polymorphisms (Seq. Id. No. 8) in the MRSA III section of GyrA disclosed herein for Staphylococcus aureus isolates C83, C84, C87 which are associated with drug resistance. This sequence corresponds to MSRA III of FIG. 3 . The polymorphic sequence is compared against non-methicillin resistant S. aureus Genebank sequence M86227 (Seq. Id. No. 33).
FIG. 11 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrB gene showing the location and sequence of each of the polymorphisms (Seq. Id. Nos. 9 and 37) in GyrB disclosed herein for E. coli strains 0157:H7 and 055:K59(B5):H—. The polymorphic sequence is compared against E. coli strain K-12 M61655 (Seq. Id. No. 34).
FIG. 12 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrB gene showing the location and sequence of each of the polymorphisms in GyrB disclosed herein for Shigella boydii isolate ATCC 35964 (Seq. Id. No. 10) and Shigella sonnei isolate 29930 (Seq. Id. No. 11). The polymorphic sequence is compared against E. coli strain K-12 (Seq. Id. No. 35).
FIG. 13 is a DNA sequence identity chart showing a lineup of the nucleic acid sequence in the GyrB gene showing the location and sequence of each of the polymorphisms (Seq. Id. No. 12) in GyrB disclosed herein for Shigella flexneri . The polymorphic sequence is compared against E. coli strain K-12 (Seq. Id. No. 36).
FIG. 14 is a schematic of one embodiment of how the polymorphisms disclosed herein can be used in nucleic acid amplification techniques to identify the presence of the polymophism.
FIG. 15 depicts the results of amplification following the scheme represented in FIG. 14 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides sets of point mutations or polymorphisms within the topoisomerase II subunit-encoding genes of the GyrA, GyrB, and parC loci. These polymorphisms allow the identification of E. coli O157:H7, Shigella flexneri, S. sonnei, S. boydii , and methicillin resistant Staphylococcus aureus.
The present invention further provides regions of nucleic acid sequences within the topoisomerase II subunit-encoding genes (i.e. GyrA, GyrB, and parC) that flank the identified polymorphisms and are useful for designing amplification-primers that can be used in the identification of pathogenic and drug resistant strains of microorganisms. These primer sequences are in some cases contiguous with (i.e. adjacent to) the identified polymorphisms and may, in some instances, include within the primer sequence the identified polymorphisms.
The present invention further provides amplification-primer sequences within the topoisomerase II subunit-encoding genes for GyrA that flank the identified polymorphisms associated with methicillin resistance in strains of Staphylococcus aureus.
The location of specific polymorphisms associated with particular organisms and which comprise embodiments of the invention are as follows:
(1) In E. coli strain O157:H7 and 055:K59(B5):H—, as compared to nonpathogenic E. coli strain K12, a polymorphism is located within a 91 base-pair region of the GyrA gene starting from position 3 of codon 69 to position 3 of codon 99. The relevant polymorphism is a guanine (G) to adenine (A) substitution in the third position of codon 84. (Seq. Id. No. 1) FIG. 6 . (2) In E. coli strains O157:H7 and 055:K59(B5)H— as compared to nonpathogenic E. coli strain K-12, a polymorphism is located within a 102 base-pair region of the GyrB gene starting from position 3 of codon 236 to position 2 of codon 270. The relevant polymorphism is a cytosine (C) to a thymine (T) substitution in the third position of codon 251 (Seq. ID. Nos. 9 and 37) FIG. 11 . (3) In Shigella boydii , isolate ATCC 35964, as compared to nonpathogenic E. coli strain K-12, a polymorphism is located within a 96 base-pair region of the GyrB gene starting from position 3 of codon 149 to position 2 of codon 181. The relevant polymorphism is a thymine (T) to a cytosine (C) substitution in the third position of codon 166. (Seq. Id. No. 10) FIG. 12 . (4) In Shigella sonnei , isolate ATCC 29930, as compared to nonpathogenic E. coli strain K-12, a polymorphism is located within a 96 base-pair region of the GyrB gene starting from position 3 of codon 149 to position 2 of codon 181. The relevant polymorphism is a guanine (G) to adenine (A) substitution in the third position of codon 164. (Seq. Id. No. 11) FIG. 12 . (5) In Shigella flexneri , as compared to nonpathogenic E. coli strain K-12, a polymorphism is located within a 91 base-pair region of the GyrB gene starting from position 1 of codon 167 to position 3 of codon 197. The relevant polymorphism is a cytosine (C) to a thymine (T) substitution in the third position of codon 181. (Seq. Id. No. 12) FIG. 13 . (6) In E. coli strain O157:H7 and 055:K59(B5):H—, as compared to nonpathogenic E. coli strain K12, a polymorphism is located within a 91 base-pair region of the parC gene starting from position 1 of codon 121 to position 1 of codon 151. The relevant polymorphism is a cytosine (C) to a thymine (T) substitution in the first position of codon 136. (Seq. Id. No. 2) FIG. 7 . (7) In Shigella boydii , isolate ATCC 35964, as compared to nonpathogenic E. coli strain K12, a polymorphism is located within a 91 base-pair region of the parC gene starting from position 3 of codon 134 to position 3 of codon 164. The relevant polymorphism is a cytosine (C) to a thymine (T) substitution in the third position of codon 149. (Seq. Id. No. 3) FIG. 8 . (8) In Shigella flexneri , isolate ATCC 29903, as compared to nonpathogenic E. coli strain K12, a polymorphism is located within 95 base-pair region of the parC gene starting from position 2 of codon 185 to position 3 of codon 216. The relevant polymorphism is a cytosine (C) to a thymine (T) substitution in the third position of codon 201. (Seq. Id. No. 4) FIG. 9 . (9) In Staphylococcus aureus , isolates C83, C84, and C87, as compared to non-methicillin resistant S. aureus Genebank sequence M86227, a polymorphism is located within a 98 base-pair regions of the GyrA gene starting from position 2 of codon 69 to position 3 of codon 101. The relevant polymorphism is a cytosine (C) to thymine (T) substitution in the second position of codon 84. (Seq. Id. No. 5) FIG. 10 a. (10) In Staphylococcus aureus , isolates C300 and ATCC 33591, as compared to non-methicillin resistant S. aureus Genebank sequence M86227, a polymorphism is located within a 98 base-pair regions of the GyrA gene starting from position 2 of codon 69 to position 3 of codon 101. The relevant polymorphism is a thymine (T) to cytosine (C) substitution in the third position of codon 86. (Seq. Id. No. 6) FIG. 10 a. (11) In Staphylococcus aureus , isolates C300 and ATCC 33591, as compared to non-methicillin resistant S. aureus Genebank sequence M86227, a polymorphism is located within a 91 base-pair regions of the GyrA gene starting from position 3 of codon 112 to position 3 of codon 142. The relevant polymorphism is a guanine (G) to adenine (A) substitution in the third position of codon 127. (Seq. Id. No. 7) FIG. 10 b. (12) In Staphylococcus aureus , isolates C83, C84, and C89, as compared to non-methicillin resistant S. aureus Genebank sequence M86227, a polymorphism is located within a 88 base-pair regions of the GyrA gene starting from position 3 of codon 157 to position 3 of codon 186. The relevant polymorphism is a thymine (T) to adenine (A) substitution in the third position of codon 172. (Seq. Id. No. 8) FIG. 10 c. (13) In Staphylococcus aureus , isolates C83, C84, and C89, as compared to non-methicillin resistant S. aureus Genebank sequence M86227, a polymorphism is located within a 88 base-pair regions of the GyrA gene starting from position 3 of codon 157 to position 3 of codon 186. The relevant polymorphism is a cytosine (C) to adenine (A) substitution in the third position of codon 176. (Seq. Id. No. 8) FIG. 10 c.
The invention contemplates that the identified polymorphisms can be used in a variety of ways. In one embodiment, they are incorporated into oligonucleotide probes for use in RFLP analysis or hybridization experiments. In a second embodiment, the polymorphisms are used in identifying strains by nucleic acid amplification techniques. Techniques for amplification of nucleic acid sequences are well known in the art and include such procedures as polymerase chain reaction (PCR), reverse transcription PCR, and strand displacement amplification (SDA). In a third embodiment, the polymorphisms may be incorporated in capture and capture mediator probes for use in conjunction with electronic microchip hybridization platforms. The uses as disclosed are not meant to be exclusive and, as one skilled in the art will recognize, the disclosed uses are only meant to represent characteristic examples of how the point mutations can be used in diagnostic assays.
Example I
In one embodiment, amplification of nucleic acids containing a polymorphism can be carried out. For example, some polymorphisms comprise multiples of point mutations in the topoisomerase genes. As schematically diagramed in FIG. 14 , oligonucleotide primers to be used in such an amplification reaction are designed so that at least one primer has at the respective 3′ terminal base a nucleotide that is complementary to a single polymorphism (i.e. mutation) base of one strand of the gene. Designing the primer to have the 3′ base complement a specific polymorphism will allow detection of the polymorphism by the amplification of the sequence bounded by the primers (if complementation occurs), or the detection of the absence of the polymorphism by the non-amplification of the sequence bounded by the primers (if complementation does not occur). The possibility for such detection is due to the well known phenomenon that extension and amplification is unfavored where the 3′ base of the amplification primer is mismatched to the template sought to be amplified. Thus, if the mutation is present in the sample, the primers will be extended to produce amplified sequence bracketed by the primers. Conversely, if the mutation in the test sample is not present, the primers will be ineffective as amplification primers. The technique is equally applicable in reverse in that at least one of the 3′ bases may be complimentary to the wild type sequence wherein amplification will occur only if the wild type sequence is present whereas if the polymorphism is present, no amplification will be observed.
For example, Seq. Id. No. 13 incorporating the polymorphism base on the 3′ end can be used with Seq. Id. No. 14 (designed from the 3′end of the 98 base fragment containing the polymorphism) ( FIG. 10 a ) to amplify a short fragment within the 98 base fragment which will contain the polymorphism associated with methicillin resistant S. aureus isolates C83, C84, and C87. No amplification will occur unless the polymorphism is present.
Seq. Id. No. 13 5′ CACCCTCATGGTGACTT3′
Seq. Id. No. 14 5′ ATAACGATAACTGAAATC 3′
The 3′ base of Seq. Id. No. 13 is complementary to the mutant polymorphism at codon 84, while the 3′ base of Seq. Id. No. 14 is complementary to the wild type sequence at codon 96.
Alternatively, instead of Seq. Id. No. 14, Seq. Id. No. 15 may be used with Seq. Id. No. 13.
Seq. Id. No. 15 5′CGTTGCCATACCTACCGCT 3′
In this instance, Seq. Id. No. 15 has a 3′ base that is complementary to the mutant polymorphism at position 176. ( FIG. 10 c ) Amplification of the sequence intervening that flanked by sequences 13 and 15 will allow additional observation of the polymorphism at codon position 172 by either sequencing the amplified segment or performing an additional amplification reaction using Seq. Id. Nos. 13 with 16 on the segment that was amplified using Seq. Id. Nos. 13 and 15. Seq. Id. No. 16 contains a base complementary to a polymorphism specific for methicillin drug resistance at the 3′ terminus of this primer. for the polymorphism at codon 172. ( FIG. 10 c )
Seq. Id. No. 16 5′ CCGCTATACCTGATGCT 3′
Specific reaction conditions and related amplification methodology is routine and well understood in the art whether using polymerase chain reaction (“PCR”) amplification or another amplification technique.
Example II
Methicillin resistant S. aureus isolates C300 and ATCC 33591 can be detected using oligonucleotid primers Id. Seq. Nos. 17 and 18.
Seq. Id. No. 17 5′GGTGACTCATCTATC3′
Seq. Id. No. 18 5′ATTTTAGTCATACGT3′
Primer 17 has a 3′ base that is the polymorphism at position 3 of codon 86 of GyrA ( FIG. 10 a ) while primer 18 is an oligonucleotide having its 3′ base complementary to the polymorphism at position 3 of codon 127 of GyrA ( FIG. 10 b ).
Example III
Pathogenic strains of E. coli O157:H7 and 055:K59(B5):H— having polymorphisms in the parC gene may be identified using hybridization techniques and the oligonucleotide sequence Id. No. 19. ( FIG. 7 )
Seq. Id. No. 19 5′GCGAGTTGGGGCA3′
Pathogenic strains of Shigella boydii isolate 35964 having polymorphisms in the parC gene may be identified using hybridization techniques and the oligonucleotide sequence Id. No. 20. ( FIG. 8 )
Seq. Id. No. 20 5′CGACGGTACTTTGC3′
Pathogenic strains of Shigella flexneri isolate 29903 having polymorphisms in the parC gene may be identified using hybridization techniques and the oligonucleotide sequence Id. No. 21. ( FIG. 9 )
Seq. Id. No. 21 5′CCGAAAACTACGCTC3′
Example IV
Pathogenic strains of E. coli O157:H7 and 055:K59(B5):H—, Shigella boydii isolate 35964, Shigella sonnei isolate 29930, and Shigella flexneri having polymorphisms in the GyrB gene may be identified using hybridization techniques and the oligonucleotide sequences Id. Nos. 22 through 25 respectively. ( FIGS. 11 , 12 , 25 and 13 )
Seq. Id. No. 22 5′CCGGAAATTGTTGAAC3′
Seq. Id. No. 23 5′GGCGCAACCGCAA3′
Seq. Id. No. 24 5′GCGAAGCAAGGGC3′
Seq. Id. No. 25 5′AAAATCCTTAACGTCG3′
Example V
Pathogenic strains of E. coli O157:H7 and 055:K59(B5):H— having polymorphisms in the GyrA gene may be identified using hybridization techniques and the oligonucleotide sequence Id. No. 26. ( FIG. 6 )
Seq. Id. No. 2 5′ACTCGGCAGTTTATG3′
BRIEF DESCRIPTION OF THE SEQUENCE LISTING
SEQ. ID. No. 1 is a region of the GyrA gene from E. coli strains O157:H7 and 055:K59(B5):H— containing a novel polymorphism of an adenine at position 46 of the sequence listed.
SEQ. ID. No. 2 is a region of the parC gene from E. coli strains O157:H7 and 055:K59(B5):H— containing a novel polymorphism of a thymine at position 46 of the sequence listed.
SEQ. ID. No. 3 is a region of the parC gene from Shigella boydii isolate 35964 containing a novel polymorphism of a thymine at position 45 of the sequence listed.
SEQ. ID. No. 4 is a region of the parC gene from Shigella flexneri isolate 29903 containing a novel polymorphism of a thymine at position 45 of the sequence listed.
SEQ. ID. No. 5 is a region of the GyrA gene from Staphylococcus aureus isolates C83, C84, and C87 containing a novel polymorphism of a thymine at position 46 of the sequence listed.
SEQ. ID. No. 6 is a region of the GyrA gene from Staphylococcus aureus isolates C300, and ATCC 33591 containing a novel polymorphism of a cytosine at position 53 of the sequence listed.
SEQ. ID. No. 7 is a region of the GyrA gene from Staphylococcus aureus isolates C300, and ATCC 33591 containing a novel polymorphism of an adenine at position 45 of the sequence listed.
SEQ. ID. No. 8 is a region of the GyrA gene from Staphylococcus aureus isolates C83, C84, and C87 containing novel polymorphisms of an adenine at positions 45 and 58 of the sequence listed.
SEQ. ID. No. 9 is a region of the GyrB gene from E. coli strains O157:H7 containing a novel polymorphism of a thymine at position 46 of the sequence listed.
SEQ. ID. No. 10 is a region of the GyrB gene from Shigella boydii isolate number 35964 containing a novel polymorphism of a cytosine at position 52 of the sequence listed.
SEQ. ID. No. 11 is a region of the GyrB gene from Shigella sonnei isolate number 29930 containing a novel polymorphism of an adenine at position 45 of the sequence listed.
SEQ. ID. No. 12 a region of the GyrB gene from Shigella flexneri isolate number 29903 containing a novel polymorphism of a thymine at position 45 of the sequence listed.
SEQ. ID. Nos. 13 to 26 are oligonucleotide primers containing a base that is complementary to a polymorphism as disclosed herein or that is within the disclosed region of the gene containing the polymorphism.
SEQ. ID. Nos. 27 to 36 are oligonucleotide sequences of E. coli strain K-12.
SEQ. ID. No. 37 is a region of the GyrB gene from E. coli strain 055:K59(b5):H— containing a novel polymorphism of a thymine.
The present invention has been described above with reference to preferred embodiments. It would be obvious to one of ordinary skill in the art that many additions, deletions and changes can be made without departing from the spirit and the scope of the invention as claimed below. | Novel polymorphisms of prokaryotic topoisomerase type II Gyr A, Gyr B and parC gene loci are provided. These polymorphisms differentiate very closely related organisms and provide a means to identify pathogenicity and drug resistance. For example, drug resistance such as resistance to methicillin, a drug which is not metabolically tied to topoisomerase function, may be determined by polymorphisms in the Gyrase A locus. Identification of such drug resistance by such unrelated loci is indicative of heretofore unrecognized [sub]species of Staphylococcus aureus. | 2 |
STATEMENT OF GOVERNMENT INTEREST
The invention described and claimed herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of royalties thereon or therefor.
BACKGROUND AND FIELD OF THE INVENTION
The present invention relates to an ice auger extractor for retrieving augers or similar devices which have become accidently disconnected, fallen, or lodged in a bore hole.
Conventionally, a lost auger is extracted from a bore hole by fishing the auger with a line and a field fabricated hook. However, this method is time consuming and not always successful in that it often results in the loss of the auger, the core sample, and valuable field time. Various devices for retrieving an auger or similar devices from a bore hole have been proposed, as described below.
U.S. Pat. No. 2,067,009 (Hinderliter) discloses a fishing socket for retrieving pipes and sucker rods, wherein two spring-biased wedging devices 12 and 13 are slidably carried on a strip 24. The strip is detachably secured to the interior of cylindrical member 10, the interior passage of which is tapered. The wedging devices 12 and 13 are used to accommodate different-sized objects to be retrieved.
U.S. Pat. No. 1,634,935 (Donnelly) discloses a lift for sucker rods, pipes and the like. The lift includes a spring-biased body having two arms 6, which engage a collar or large portion of the pipe or rod to be lifted.
U.S. Pat. No. 2,410,262 (Breaux) discloses a device similar to the retrieval lift of Donnelly with the exception that dogs 19 are biased by a helical spring 15 extending along the longitudinal axis of the device. As shown in FIGS. 3 and 8, projections 22 of dogs engage under the coupling 23 of a stuck pipe 24.
U.S. Pat. No. 2,076,837 (Grimmelsman) discloses a core catcher for use in a core barrel or well core drill. As shown in FIG. 6, the catcher includes spring-biased dog assemblies 31 and serrated gripping elements 32, which are adjustable along the longitudinal axis of the catcher.
U.S. Pat. No. 2,103,611 (Catland et al) discloses a core catcher which includes spring-biased dog assemblies 33 and wedge-like gripping parts 35 which are adjustable along the longitudinal catcher structure.
U.S. Pat. No. 2,595,008 (Still) discloses a tool for use in gripping and pulling broken pipes from oil or like deep wells. The extractor includes a cylindrical roller or shaft 16 with a knurled surface for engaging the surface of the broken pipes.
U.S. Pat. No. 1,754,816 (Canniff) discloses a sucker rod socket for retrieving broken sucker rods or like objects from a well. The device includes a gripping ring 15 loosely mounted in the bore of the device. Gripping ring 15 includes an inner concave wall 22 which has bevelled edges or annular teeth 25 for gripping a sucker rod.
U.S. Pat. No. 1,487,440 (Butts) discloses a fishing pole which includes gripping dogs 16 disposed about the internal periphery of the tool. The lower edges of the dogs, when arranged in the canted position shown in FIG. 1, provide biting teeth 19 for engaging the outer surface of the device being recovered.
U.S. Pat. No. 1,352,172 (Brandon) discloses a drill retriever which includes a plurality of ring receiving sockets 13 adapted to receive a plurality or rings of washer members 16. The rings or washer members assume angular position shown in FIG. 6, thereby causing the bore opening walls to frictionally engage the sides of the drill to be retrieved.
U.S. Pat. No. 3,326,566 (Boyd) discloses a fishing tool which includes a plurality of pawls or dogs 17. As shown in FIGS. 1-3, the dogs include serrated edges for gripping the external surface of the sucker rod to be retrieved.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an ice auger extractor which can be used to retrieve augers or similar devices which have accidently become disconnected, fallen or lightly lodged in the walls of a bore hole.
It is another object of the present invention to provide an ice auger extractor which is easily adaptable to different bore holes of different sizes.
It is yet another object of the present invention to provide an ice auger extractor which does not require the use of a line and/or a field fabricated hook and can be easily utilized in the field.
It is a further object of the present invention to provide an ice auger extractor which is adaptable to different rod sizes, different bore hole sizes and different gripping ranges.
Another object of the present invention is to provide an ice auger extractor which is adapted to grip the smooth surfaces of cylindrical rods formed of various materials.
It is another object of the present invention to provide an ice auger extractor which is adapted to extricate and center a rod which has an end embedded in the wall of the bore hole.
It is yet another object of the present invention to provide an ice auger extractor which requires a small number of parts and is easy to assemble and use.
It is another object of the present invention to provide an ice auger extractor which is adaptable and is easily modified with interchangeable parts from a kit to operate in various situations.
It is yet another object of the present invention to provide an ice auger extractor in which the material of various parts can be varied without any or negligible effect on the operation of the device.
It summary, the disclosed invention provides an ice auger extractor for retrieving augers or similar devices from a bore hole, and which has the ability to extricate and center a rod having a free end embedded in the wall of a bore hole.
DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages and novel features of the present invention will become apparent from the following detailed description of the preferred embodiment of the invention illustrated in the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of a first embodiment of an ice auger extractor according to the present invention;
FIG. 2 is a longitudinal cross-sectional view of the ice auger extractor of FIG. 1;
FIG. 3 is a longitudinal cross-sectional view of a second embodiment of the ice auger extractor as it is being lowered into a bore hole;
FIG. 4 is a longitudinal cross-sectional view of the ice auger extractor of FIG. 3 showing an auger rod being extracted; and
FIGS. 5-7 illustrate use of the ice auger extractor of FIG. 1 in extracting an auger embedded in the wall of the bore hole.
DETAILED DESCRIPTION OF THE INVENTION
As best shown in FIG. 1, ice auger extractor A includes a lower main body portion B and an upper rod adapter C for accommodating various types of drive assemblies which may be used in the field. In an alternative embodiment, bore adapter D may be connected with the auger extractor A for centering an auger rod, as shown in FIGS. 5-7.
The main body portion B is a longitudinal housing 2 having an upper section 4 and a lower section 6. The housing 2 includes a bore 8 which extends along the longitudinal axis of the housing and has an opening 10 in lower section 6 thereof. As shown in FIGS. 1 and 2, the external diameter of the lower section 6 of the housing 2 is greater than the external diameter of the upper section 4. However, the diameter of bore 8, which extends from upper section 4 through lower section 6, remains constant throughout the length thereof.
The lower section 6 includes a recess 12 which extends longitudinally parallel to the axis or bore 8 in a peripheral portion thereof. As best seen in FIG. 2, recess 12 includes a vertical portion 13 and a horizontal base portion 15 and is substantially L-shaped and receives a detent or latching mechanism 14 for catching or gripping an auger rod E. The detent or latching mechanism 14 includes a cam 22 and an extension spring 16 having end hooks 18 and 20 biased thereto. The latching mechanism 14 is positioned in the recess 12 such that the spring 16 extends in vertical portion 13 of recess 12, and cam 22 is pivotable about dowel pin 24 in the base portion 15 of recess 12. The vertical portion 13 of the recess 12 includes a number of vertically spaced holes 26 located on either side thereof for receiving a securing rod 28 therein. Holes 26 open to the exterior surface of the housing 2, so that securing rod 28 can be easily inserted or taken out by using an elongated pin or the like (not shown). The end-hook 18 of extension spring 16 is secured to the securing rod 28 and the end-hook 20 is secured in hole 30 of cam 22. Therefore, cam 22 pivots either clockwise or counterclockwise about pin 24, thereby compressing or extending the spring 16. As one of ordinary skill in the art will appreciate, positioning securing rod 28 into a different set of holes 26 varies the force exerted by the spring 16 on cam 22.
The cam 22 includes cam edges 32 and 34. As shown in FIG. 4, cam edge 34 is serrated for engaging the surface of auger rod E. As shown in FIG. 3, counterclockwise movement of cam 22 causes the cam edge 32 to come to rest on surface 36 of recess 12, thereby forcing rod 40 to farside of bore 8. Recess surface 36, therefore, functions as a stop for cam 22 during counterclockwise movement thereof.
A ring 38, made from a resilient material, is positioned within the bore 8 in the upper section 4 of housing 2 as best shown in FIG. 2. The ring 38 functions as a cushion for the broken end 40 of auger rod E and further acts as a spring to facilitate easy removal of the auger rod E from the device A. The hole 39 of the resilient ring 38 communicates with neck opening 41 of upper section 4 of housing 2. The neck opening 41 is open to the exterior and is provided for ease of cleaning the bore 8 which may become clogged with snow or other field-material.
As shown in FIGS. 3 and 4, opening 10 of housing 2 includes a frusto-conical surface 42 for guiding the auger rod E towards the center of extractor A. As shown in FIGS. 3 and 4, lower section 6 of housing 2 includes a transversely extending screw-threaded hole 44 for receiving screw 46 when bore adapter D is connected with main body portion B of the extractor A. (See FIG. 2). Although screw-threaded hole 44 is shown to be located radially opposite to recess 12, one of ordinary skill will appreciate that the positioning of recess 12 and screw-threaded hole 44 can be varied.
BORE ADAPTER
As shown in FIGS. 1 and 2, bore adapter D includes sleeve 48 having an upper portion 50 and a lower portion 52. The diameter of the upper portion 50 is less than the diameter of the lower portion 52. Sleeve 48 is open at both ends and includes a bore 54 extending therethrough. Upper opening 56 of bore 54 is adapted to receive the lower section 6 of housing 2 therein. As shown in FIG. 2, lower opening 58 of the bore 54 includes a frusto-conical surface 60 for guiding the auger rod E toward the center thereof. Sleeve 48 further includes a vertically extending recess 62 which is formed in a peripheral portion thereof. Recess 62 of sleeve 48 is aligned with recess 12 of housing 2 such that when the lower section 6 of the housing 2 is received in bore 54 of bore adapter D, a portion of the detent or latching mechanism 14 extends into recess 62. An L-shaped snagging hook 64 extends downwardly from hole 66 formed in a peripheral portion of the sleeve 48.
The upper portion 50 of sleeve 48 includes a transversely extending orifice 57 which is aligned with screw-threaded hole 44 so that screw 46 may be positioned therein for holding main body portion B in tight non-rotatable engagement with bore adapter D.
As shown in FIG. 2, an adapter sleeve F having an external diameter corresponding to the diameter of bore 8 may be inserted into lower section 6 of housing 2 for decreasing the internal diameter of the bore 8. Adapter sleeve F is attached to main body portion B via screw 46. This adapter may be used with or without bore adapter D. This construction allows the ice auger extractor A to retrieve a very thin auger rod. By inserting various adapter sleeves having varying internal diameter, the effective diameter of bore 8 can be varied to thereby allow the retrieval of auger rod of varying diameters.
As shown in FIG. 2, the adapter sleeve F has a bore 68, the upper opening 70 of which communicates with the interior of housing 2 and the lower opening 72 of which is aligned with opening 10 of housing 2. The lower opening 72 of adapter sleeve F includes a frusto-conical surface 74 which is aligned with the frusto-conical surface 42 of housing 2 and the frusto-conical surface 60 of bore adapter D. In this way, a continuous frusto-conical surface is formed which guides the ice auger toward the center of the extractor A.
Adapter sleeve F includes a vertically extending opening 76 which is aligned with the lower base portion opening 15 of housing 2. Therefore, when cam 22 pivots, a portion of cam 22 extends through recess 76 and into bore 68. The upper edge 78 of adapter sleeve F is tapered to facilitate insertion into the bore 8 of the housing 2.
The bore adapter D further includes a platform 55 for resting the lower end 3 of housing 2 thereon.
The lower end 3 of housing 2 includes inwardly inclined surface 7 for the easy insertion of the housing into bore 54 of the sleeve 48.
Various rod adapters H can be connected to the main body portion B of the extractor A through the use of a set screw 80 which locks on the shank 81 of the adapter H in bore 41 of upper section 4 through screw thread 82.
OPERATION
In operation, the ice auger extractor A is lowered into a bore hole G to retrieve the auger rod E which has become accidently disconnected, fallen or lodged therein. As best seen in FIG. 3, as the auger rod E makes its way into bore 8 of housing 2, the cam 22 rotates counterclockwise (shown by arrow in FIG. 3) from its initial position shown in FIG. 2. As the cam 22 rotates counterclockwise, the extension spring 16 is pulled downwardly and due to the exerted compression force, applies an upwardly and radially extending force for causing the cam 22 to engage the outer surface of the auger rod E. This furthermore causes the rod E to shift radially relative to adapter A so that the rod E engages the wall provided by bore 8 or bore 68. Once the auger rod E has travelled a sufficient distance into the bore 8 of housing 2, the extractor A may then be gently lifted as shown in FIG. 4. Preferably, the end 40 engages ring 38 before lifting is begun. During lifting of the extractor A, the auger rod E tends to slide downwardly due to the gravitational force, however, cam 22 rotates clockwise (shown by arrow in FIG. 4) due to the compression force exerted by the spring 16 and the cam edge 34 grips and frictionally holds the auger rod E within the bore 8 and against the wall thereof. Auger rod E may therefore be retreived by lifting the extractor A without fear the rod E will slip therefrom.
In the instances where the free end of rod E is embedded into the wall of the bore G, or is positioned non-concentric with the bore hole due to angular inclination or otherwise, then the L-shaped hook 64 or bore adapter D may be used to center the auger rod E relative to the coaxial bores 8, 10 and 68. As shown in FIGS. 5-7, the auger extractor A along with the bore adapter D is lowered into the bore hole G until the extension of snagging hook 64 is below end 40. Then the entire device is rotated until the auger rod E is centered. Once the auger rod E is centered and extends substantially vertically in the bore hole G, then the extractor A may be further be lowered because the frusto-conical surface 60 guides the auger rod E towards the center of the extractor A. The rod E is then locked in the bores by the spring-operated action of the detent mechanism 14 as before. Various drill rod adapters H shown in FIG. 2 can be easily installed by loosening set screw 80, removing adapter H, replacing with another adapter, and tightening set screw 80. | An ice auger extractor for retrieving augers or similar devices from a boreole includes a cylindrical housing and a spring-biased locking cam positioned in a vertically extending recess. The recess is substantially L-shaped and extends in a portion of periphery of the housing. The cam includes a serrated edge which secures the auger rod within the bore of the housing before its retrieval. A bore adapter may be connected with the housing and includes a substantially L-shaped snagging hook for centering the auger rod in the situation where the free end of the auger rod is embedded in the wall of bore hole. The housing and the bore adapter both include frusto-conical surfaces for guiding the auger rod into the housing. | 4 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is related to nitrogen mustard analogs with arms of unequal reactivity on different nitrogen atoms. More particularly, the present invention is related to 1-(2-chloroethyl)-4-(3-chloropropyl)-piperazine, dihydrochloride or similar halo-derivatives and method of preparing the same. The new analogs are less toxic, potent, cancer chemotherapeutic agents.
2. State of the Art
Tertiary amine alkylating agents with one or two beta-haloethyl groups attached to nitrogen have been used in a variety of pharmacologic regimens. The former are employed principally as alpha adrenergic blockers and the latter, frequently described as nitrogen mustards, are cytotoxic agents. Analogs of nitrogen mustards containing a beta-haloethyl group and a gamm-halopropyl group attached to the same nitrogen have been known and reported to be effected cancer chemotherapeutic agents. Piperazine mustard, 1,4-bis(2-chloroethyl)piperazine, has also been prepared and found to be active against murine leukemia (Burchenal et al., Cancer, 4: 353, 1951), but its analog containing a beta-chloroethyl group and a gamma-chloropropyl group on different nitrogens has not been produced.
SUMMARY OF INVENTION
It is, therefore, an object of the present invention to provide new analogs of nitrogen mustard with arms of unequal reactivity on different nitrogen atoms.
It is a further object of the present invention to provide new analogs of nitrogen mustard with decreased host toxicity (LD50) but with equal or greater chemotherapeutic activity compared to mechlorethamine.
Other objects and advantages will become evident as the detailed description of the present invention proceeds.
DETAILED DESCRIPTION OF INVENTION
The above and various other objects and advantages of the present invention are achieved by new analogs of nitrogen mustard with arms of unequal reactivity on different nitrogen atoms, a preferred analog being 1-(2-chloroethyl)-4-(3-chloropropyl)-piperazine, dihydrochloride.
Unless defined otherwise, all technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned hereunder are incorporated herein by reference.
EXAMPLE 1
Preparation of 1-(2-chloroethyl)-4-(3-chloropropyl)piperazine, dihydrochloride
Preparation of 1-(2-hydroxyethyl)-4-(3-hydroxypropy)piperazine [I]:
1-(2-hydroxyethyl)-piperazine, 26 grams, freshly distilled allyl alcohol, 36 g and sodium hydroxide, 8 g are heated to 118°-120° C. for 36 hours. The viscous reaction mixture is taken up into 250 ml water, and solid potassium carbonate is added to saturate the warmed solution. A yellow oil, the product, rises to the top. It is extracted with tetrahydrofuran, the solvent evaporated, the residue dissolved in ethanol, the solution filtered, and the ethanol evaporated under vacuum to a thick oil, which solidifies on standing to give the isolated product, [I], above.
EXAMPLE 2
Preparation of 1-(2-chloroethyl)-4-(3-chloropropyl)piperazine, dihydrochloride [II]:
The dihydroxy compound, [I], 10 g, described above, is dissolved in 100 ml dimethylformamide and the solution is cooled in an ice-bath. To the solution is added carbon tetrachloride (25 ml) and triphenylphosphine (28 g) and the mixture stirred for four hours at room temperature (22°-25° C.). The solution is evaporated under vacuum and the residue taken up in 2N hydrochloric acid. The precipitate, triphenylphosphine oxide, is removed by filtration and the clear solution brought to pH 8 with 2N sodium hydroxide. It is extracted 3 times with ethyl acetate, dried with anhydrous sodium sulfate and the solvent removed by evaporation in vacuo. The oil obtained is dissolved in a minimal volume of ethyl acetate and the solution mixed with hydrochloric acid in dioxane to precipitate a white solid, the product, (II).
Of course, the amounts shown in the above examples are only illustrative. Upgrading and adjustment of various parameters described in the above methods for large scale production can be easily achieved by one of ordinary skill in the art to which the present invention belongs.
Animal studies
Male CDF 1 mice (Balb/c×DBA/2), 8-12 weeks old and weighing 22-31 grams, were placed in groups of equivalent weight, 5 or 6 animals per plastic cage with wood chip bedding and were given laboratory chow ad libitum. L1210 cells of the NCI strain were maintained in female DBA/2 mice and transplanted intraperitoneally (i.p.) into male CDF mice for experiments. They were harvested on day seven following the inoculation of 1×10 5 cells.
Chemotherapy of L1210 leukemia bearing mice
The most effective treatment schedule for mice with 1-(2-chloroethyl)-4-(3-chloropropyl)piperazine was obtained by daily intraperitoneal injections, which resulted in an increase in survival of 67% over controls (Table 1). Increased survival with the standard nitrogen mustard, mechlorethamine, was only 61%.
TABLE 1______________________________________Treatment of Mice Bearing L1210 Leukemia with1-(2-Chloroethyl)-4-(3-Chloropropyl)piperazine 2HClL1210 cells, 1 × 10.sup.5, were injected i.p. on day 0and treatment was begun i.p. on day 1.There were 6 mice per group.T/C is survival in days of treated animalsdivided by survival of controls. Mean Survival Time T/CTreatment (mg/kg) (days) (%)______________________________________0 8.2 100100 (day 1) 7.0 85*50 (day 1) 11.4 13925 (day 1) 10.0 12210 (days 1-5) 11.5 1405 (days 1-5) 9.8 1202.5 (days 1-5) 9.2 1121.25 (days 1-5) 8.8 1070 8.2 10030 (days 1-5) 8.0 98*20 (days 1-6) 12.0 14610 (days 1-7, 10) 13.7 1670 8.0 10010 (days 1-5) 12.6 158______________________________________ *T/C less than 100% is due to toxicity.
Chemotherapy against a spectrum of tumors:
Tables 2 and 3 show a drug screening summary of NSC 344007 (the compound of the present invention). It can be seen that the compound is surprisingly effective in the human tumor colony forming assay, against a number of murine tumors and in a human tumor xenograft test.
TABLE 2__________________________________________________________________________HUMAN TUMOR COLONY FORMING ASSAY **CONFIRMATION TESTING** (DOSE RESPONSE) EVALUABLE/TOTAL ASSAYS RESPONSES__________________________________________________________________________TUMOR TUMOR MGROUP GROUP O DMELANOMA 5/5 4 (80%) MEL ROVARIAN CARCINOMA 4/4 1 (25%) OVATOTAL 9/9 5 (55%) ALL GROUPSOVERALL RESPONSE 5/9 (55%)RATE AT 10OR LESS MCG/MLAN OVERALL RESPONSE RATE OF 20% OR GREATER IS THE CURRENTACCEPTABLE GUIDELINE.__________________________________________________________________________
TABLE 3__________________________________________________________________________ RATING OD CURES/SYSTEM NAME OF TUMOR ++/+/- RT SCHEDULE T/C MG/KG TOT__________________________________________________________________________3B131 B16 MELANOMA ++ IP QD1-9 260 10 3/10 3LE31 L1210 LEUKEMIA ++ IP Q D1-9 209 10 0/10 HUMAN MAMMARY TUMOR IN 3MBG5 ++ SC Q4DX3 -6 1 15 2/6 SUBRENAL CAPSULE 3M531 M5076 SARCOMA ++ IP Q4 DX4 240 20 5/10 3PS31 P388 LEUKEMIA ++ IP Q D1-5 238 10 0/5 3PO31 CYTOXAN RESISTANT P388 LEUKEMIA ++ IP Q D1-5 197 9 0/10 3C872 COLON 38 CARCINOMA + IP Q7DX2 16 20 0/10 3CDJ2 CD8F.sub.1 MAMMARY TUMOR ++ IP Q1DX 1 -43 40 0/10 3LE32 L1210 LEUKEMIA + IP QD1-9 138 10 0/10 3CP31 CIS PLATIN RESISTANT P388 LEUKEMIA + IP QD1-5 170 13 0/10__________________________________________________________________________
In summary, the compound of the present invention when tested according to the protocols of the Development Therapeutics Program, Division of Cancer Treatment, National Cancer Institute, is found to be highly active (++) against the following mouse tumors: the B16 melanoma, the CD8F1 mammary adenocarcinoma, the P388 and L1210 leukemias, the M5076 sarcoma, the cytoxan resistant P388 leukemia and active (+) in the colon 38 carcinoma, the cis-platin and L-PAM resistant P388 leukemias. It gave reproducible cures for the B16 melanoma and the M5076 sarcoma and was highly active (++) in the human mammary subrenal capsule xenograft (MX-1) and scored positive in 4 of 5 tests in the human melanoma colony forming assay (Tables 2 and 3). The results indicate that the compound of the present invention has both carcinocidal as well as carcinostatic properties.
Of course, the compounds of the present invention can be used in a pharmaceutical composition comprising a chemotherapeutically effective amount of the compound in a pharmaceutically acceptable carrier such as sterile water, physiological saline, non-toxic physiological fillers and/or buffers and the like well known in the art. The composition can be in any suitable form such as a liquid, a solid, a capsule, a tablet, a paste or creamy mixture and the like.
It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims. | New nitrogen mustard analogs with arms of unequal reactivity on different nitrogen atoms have been made. The new analogs are less toxic, potent, cancer chemotherapentic agents. | 2 |
FIELD OF INVENTION
[0001] The present inventions relate to a cleaning apparatus and a method for cleaning debris from a wellbore.
BACKGROUND
[0002] Formation damage is defined as a reduction in permeability around a wellbore, which is the consequence of drilling, completion, injection, attempted stimulation or production of the well. The mechanism of formation damage varies from well to well; however the transport of solids into and out of the wellbore is consistently an important factor. Drilling mud, drilling fluids drill-in fluids, fluid loss inhibitors, and other similar fluids can invade permeable formations, replacing native fluids adjacent to the wellbore. During replacement, solid particles invade the formation and reduce its permability by blocking flow channels. This blockage in the flow channels causes formation damage, which can result insignificant decreases in well productivity and resulting economic loss.
[0003] A variety of techniques have been developed to remove formation damage. Acidization is probably the most commonly applied technique; however this solution may often result in corrosion of the wellbore equipment and chemical incompatibilities. Additionally large volumes of acid are very expensive and can be problematic in horizontal completions. Formation damage may also be limited somewhat by pretreating the fluids used in drilling, fracturing, and perforation; however this is not an option for correcting post-completion damage.
[0004] A recent development in the area of hole cleaning is the use of the principle of cavitation for removing debris such as cuttings, pieces of rock chips, gravel, fines, asphaltenes, solids deposited to reduce fluid loss, and other particles that may interfere with the production or operation of a well. Cavitation generally refers to the formation and instantaneous collapse of innumerable tiny vapor bubbles within a fluid subjected to rapid and intense pressure changes. A liquid subjected to a low pressure (tensile stress) above a threshold ruptures and forms vaporous cavities. When the local ambient pressure at a point in the liquid falls below the liquid's vapor pressure at the local ambient temperature, the liquid can undergo a phase change, creating largely empty voids termed cavitation bubbles.
[0005] Downhole cleaning via cavitation involves attaching a cavitation tool to the end of the coiled tubing, drill pipe or work string. To do so, the production or drilling must be stopped while the cleaning apparatus is run into the hole. Fluid pumped through the tool drives a mechanical process that induces cavitation, and a flare of bubbles is released. The combined effects of the flow impact, the suction effects of the decaying bubble flare, and the implosion shock waves of the cavitation are effective to mobilize and remove debris that may be trapped in the wellbore.
SUMMARY OF THE INVENTION
[0006] The present inventions include a method for cleaning debris from a wellbore having a top and a bottom comprising inserting cleaning tool comprising a coaxial pipe in the wellbore, pumping fluid through the cleaning tool to create a fluid flow in a direction towards the bottom of the wellbore, converting the fluid flow into rotary mechanical power, agitating the debris by cavitation with at least one vortex spinner having a plurality of spinner blades, and allowing the debris to flow towards the top of the wellbore thereby cleaning the wellbore.
[0007] The present inventions include an apparatus for cleaning a wellbore comprising a coaxial pipe with a first end and a second end, at least one vortex spinner operatively connectable to the coaxial pipe between the first end and the second end, and a fluid divider arranged inside the coaxial pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention is better understood by reading the following description of non-limitative embodiments with reference to the attached drawings, wherein like parts of each of the figures are identified by the same reference characters, and which are briefly described as follows:
[0009] FIG. 1 illustrates a side view of one embodiment of a cleaning tool during production.
[0010] FIG. 2 illustrates a close-up side view of the one embodiment of the downhole cleaning tool.
[0011] FIG. 3 illustrates a side view of another embodiment of the cleaning tool.
[0012] FIG. 4 illustrates a top view of the cleaning tool.
[0013] FIG. 5 illustrates a top view of the cleaning tool with a ball dropped to deactivate one of the nozzles.
[0014] FIG. 6 illustrates a side view of the cleaning tool with a ball dropped to deactivate one of the nozzles.
[0015] FIG. 7 illustrates a side view of another embodiment of the cleaning tool during production.
DETAILED DESCRIPTION
[0016] For the purpose of this application, the terms used shall be understood as follows. The term “horizontal” or “deviated” well is used to describe an oil or gas well drilled at an angle at least 30 degrees from vertical. The term “debris” is used to mean cuttings, pieces of rock chips, gravel, fines, asphaltenes, solids deposited to reduce fluid loss, and other particles that may interfere with the production or operation of a well.
[0017] Referring to FIG. 1 , one embodiment of downhole cleaning tool 100 is shown installed in wellbore 101 during production. Cleaning tool 100 is attached to a portion of tubing 102 and lowered into the well. In this embodiment, the cleaning tool is shown integrated with the production tubing. Alternatively the cleaning tool may be inserted into the well with a wireline, stinger, or another joint of tubing. In the embodiment shown, only one cleaning tool is depicted; however, multiple tools may be installed at various intervals along the tubing to increase cleaning efficiency.
[0018] Cleaning tool 100 may be made up of coaxial pipe 103 , fluid divider 104 , and vortex spinner 105 connectable around the circumference of the coaxial pipe. Connectors 106 hold the spinner in place, decrease friction of vortex spinner 105 while rotating, and seal the fluid flow from interior pipe to outside. FIG. 2 shows a close-up view of a portion of the downhole cleaning tool from FIG. 1 in which connectors 106 are roller bearings, or any similar connection apparatus. Vortex spinner 105 comprises spinner housing 107 , interior spinner blades 108 , and exterior spinner blades 109 .
[0019] During operation, fluid is pumped down production tubing 102 through cleaning tool 100 towards the bottom of the wellbore as represented by arrow 110 . When the fluid moves through fluid divider 104 , the pressure decrease causes the velocity of the fluid to increase. Alternatively fluid divider 104 may be removed from the design. The fluid hits interior spinner blades 108 and rotates vortex spinner 105 at a speed sufficient to induce cavitation. The interior and exterior spinner blades and may be connected to the vortex spinner in any arrangement; however, a spiral, helical, or slanted configuration is preferred. Vortex spinner 105 and exterior spinner blades 109 agitates the fluid in annulus 112 and releases debris attached to the wall of the wellbore. The fluid then may pass through the rest of the assembly. Mobilized debris may be circulated along annulus 112 (according to arrow 111 ) to the surface.
[0020] FIG. 3 shows an alternative embodiment of the downhole cleaning tool. In this embodiment, nozzles 301 may be attached to vortex spinner 105 to enhance the cleaning process. The number of nozzles and angles at which the nozzles are positioned may be adjusted based on well conditions. Optionally the nozzles may be equipped with nozzles heads (not shown) to direct fluid as it exists the nozzle. Optionally the nozzles may be threaded or otherwise manufactured to direct fluid flow. When fluid is pumped down along arrow 110 , a portion may pass through nozzle 301 to agitate debris 302 and loosen it from the wellbore. The rest of the fluid continues through the tool to activate rotate the components to induce cavitation.
[0021] FIG. 4 shows a top view of the embodiment of the downhole cleaning tool from FIG. 3 in wellbore 101 . Coaxial pipe 103 is shown encircled by vortex spinner 105 . A plurality of nozzles 301 extend through vortex spinner 105 . In this embodiment, four nozzles are shown; however more could be included in a variety of arrangements. Each nozzle may be equipped with a nozzle head 402 at its end, which can be adjusted to set the angle at which fluid exists the tool. Each nozzle may be connected to a hole in the inner wall of vortex spinner 105 . Fluid breaker 403 encircles the inner wall of vortex spinner 105 beneath the holes leading to the nozzles.
[0022] During operation, fluid flows across fluid divider 104 and experiences an increase in velocity. Alternatively, the fluid divider could be omitted and the vortex spinner driven with the natural velocity of the fluid. A portion of the fluid hits interior spinner blades 108 and causes coaxial pipe 103 (or is it vortex spinner 105 ?) to rotate at a specified speed. A different portion of the fluid may enter nozzles 301 and is shot against the formation to loosen debris. The rest of the fluid may continue through the tool to activate the cavitation process via vortex spinners 105 . One possible path of the fluid is shown by arrows 404 ; however, others paths are possible.
[0023] When the operator no longer requires the use of one of the nozzles, controllable passageways capable of stopping fluid communication in one or all of the nozzles may be used. In one embodiment, a ball 501 may be dropped to deactivate the nozzle. FIG. 5 shows a top view of the tool with ball 501 resting on fluid breaker 403 and blocking the hole, which leads the leftmost nozzle. FIG. 6 shows a side view of the same scenario. Alternatively another mechanism known in the industry to block flow such as a flapper valve. Alternatively, as shown in FIG. 7 , the vortex spinners may be removed and replaced with pipe 301 so that the tool is simplified to only include the nozzle cleaning mechanism. Any other method that achieves the effect of the controllable passageways may be used.
[0024] Advantages of some embodiments of the invention may include one or more of the following:
Allows the assembly of one or multiple fluid-driven rotary cleaning subs as needed anywhere in the completion eliminating the limitations of tools that may only be installed at the end of the tubing Eliminates additional trips required to disassemble and insert a cleaning assembly Reduces or eliminates backreaming Prevents settling of drill cuttings Increases lifetime of completion equipment and other downhole tools
[0030] Those of skill in the art will appreciate that many modifications and variations are possible in terms of the disclosed embodiments, configurations, materials, and methods without departing from their spirit and scope. Accordingly, the scope of the claims appended hereafter and their functional equivalents should not be limited by particular embodiments described and illustrated herein, as these are merely exemplary in nature. | A method for cleaning debris from a wellbore having a top and a bottom comprising inserting cleaning tool comprising a coaxial pipe in the wellbore, pumping fluid through the cleaning tool to create a fluid flow in a direction towards the bottom of the wellbore, converting the fluid flow into rotary mechanical power, agitating the debris by cavitation with at least one vortex spinner having a plurality of spinner blades, and allowing the debris to flow towards the top of the wellbore thereby cleaning the wellbore. | 4 |
This invention relates to a boar cart for use in transporting a boar adjacent to a series of pens containing sows during insemination of the sows.
BACKGROUND OF THE INVENTION
In high intensity rearing of pigs, sows after farrowing are moved to an area where they are maintained in separate pens awaiting insemination at the suitable time of estrous. The sows are maintained in separate pens in rows on one or both sides of dividing alleyways so that the farm hand can move along the row of sows both at the front and rear to access the sows for insemination and for various other purposes.
The alleyways between the rows can range in width from 24 inches up to 36 inches in most cases and in some cases the alleyways are wider still. The alleyways are defined between rows of pens and of course at the end of the rows the alley turns through a right angle so that passage can be obtained along one end of the rows and then back between the next set of rows where another right angle turn is required.
It is well known in artificial insemination that it is desirable to bring a boar to the sows both for the purposes of stimulating the sows by close physical contact with the boar and for determining whether a particular sow is in estrous. The presence of the boar is known to improve the effectiveness of the artificial insemination both by allowing the farm hand to more accurately determine the presence of estrous and in addition to place the sow in a more accepting condition for the insemination.
Conventionally a boar is led along the front of the stalls so as to physically contact or approach each sow in turn while the farm hand takes the necessary actions for carrying out insemination of those sows found to be in estrous. This requires the manual handling of a very large powerful animal by one or more additional farm hands.
Attention has therefore been given to design a device which allows the boar to be moved or transported along the alleyway in front of the row of sows in their pens while the farm hand carries out the necessary actions for insemination. It is clearly desirable if such a device is remotely controllable so that the farm hand at the rear of the animal can operate the device to move the boar to the required position adjacent the sow involved.
Previous carts have been manufactured for this purpose which are rigid and relatively long thus preventing their movement around corners from one alleyway to another. Because of this difficulty such carts have little commercial applicability and thus have achieved little success, although some limited use in specific barns has been obtained.
In U.S. Pat. No. 6,196,975 (Labrecque) of the present assignees and issued March 2001 is shown a cart for transporting a boar for use in insemination of sows. The cart is formed in two separate pieces which allow the cart to be separated at a corner into the two pieces so that the cart can be manoeuvred around the corner. However this arrangement had the disadvantage that the animal may have to be removed from the cart at the corner and returned to the cart after the corner.
In U.S. Pat. No. 6,336,426 now assigned to the present assignees is disclosed a modified cart of the type shown in the above patent in which the cart is formed in two sections which are pivotal about a vertical pivot axis on the center line so that the cart can be articulated with the animal still contained around a corner. The cart disclosed also is arranged to reduce the overall effective length of the cart at the corners by providing a bowed front and rear panel.
In a brochure published by Jerome Mack is disclosed a simple cart without a floor which guides the animal in a required direction along an alleyway.
However the articulated carts still have difficulty in negotiating the narrowest alleys at the corners. In addition, the articulation is a relatively expensive construction so that an alternative arrangement for allowing cornering even at wider alleyways is desirable.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide an improved cart for transporting an animal which is shaped an arranged to allow an improved cornering action of the cart at corners between alleyways.
According to the invention therefore there is provided a cart for carrying an animal through alleyways and around corners in the alleyways comprising:
a cage assembly for containing the animal including a cage floor on which the animal stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the animal so that the animal is maintained extending longitudinally of the cage assembly, a cage front assembly and a cage rear assembly for confining the animal against forward and rearward movement;
the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the animal within the cage assembly;
at least one of the cage front assembly and the cage rear assembly comprising two upright side panels and a coupling member therebetween;
each of the side panels having a first upright edge connected to a respective one of the cage sides for pivotal movement about an upright axis at the cage side;
each of the side panels having a second edge generally parallel to the first upright edge and spaced away from the cage side such that pivotal movement of the side panel about the upright axis causes the side panel to swing side to side relative to the cage side;
the coupling member being connected between the side panels at the second edges thereof and being arranged to allow relative pivotal movement between each side panel and the coupling member;
the side panels and the coupling member being free to pivot such that contact between the side panel of one cage side and a wall of an alleyway will cause the side panels and the coupling member to pivot away from the contact toward the other cage side.
Preferably the coupling member has a width between the side panels which is less than the spacing between the cage sides such that the side panels extend generally outwardly from the cage assembly and toward a center line of the cage assembly.
While it is preferred that both the front and rear cage assemblies are formed from the panels and the coupling member, an advantage may in some cases be obtained merely by forming one of these constructions in this manner while the other is merely a fixed panel of the type described in one or other of the above patents.
Preferably the side panels at the front are generally planar.
Preferably the side panels at the rear each include a first generally planar portion at a first angle relative to the respective cage side and a second generally planar portion at a second greater angle to the cage side.
Preferably the coupling member at the front comprises a panel closing the space between the second edges, thus preventing the animal from viewing directly ahead and from inserting its snout into the pivot area.
Preferably the coupling member at the rear comprises a merely link connecting the second edges of the side panels but leaving the space therebetween open, since the rear assembly needs only to confine the rear end of the animal.
Preferably the link at the rear end of the cart located between side panels at the rear end is removable to allow the side panels at the rear end to pivot apart for loading and unloading of the animal.
Preferably the coupling member or link at the rear is arranged to allow movement of the side panels from a position in which the second edges are spaced apart to a position in which the second edges overlap.
In one arrangement the cage assembly has a front portion including parts of the cage sides and the front cage assembly for receiving the front feet and forward portion of the animal and a rear portion including parts of the cage sides and the rear cage assembly for receiving the rear feet and rearward portion of the animal and wherein the front portion is connected to the rear portion for pivotal movement about at least one vertical pivot axis to allow the cage assembly to navigate around a corner from one alleyway to another.
In another construction the cage assembly has a rigid structure with the cage sides parallel and both the cage front assembly and the cage rear assembly each comprise two upright side panels and a coupling member therebetween.
It is a further object of the present invention to provide an improved cart for transporting an animal which is arranged to allow an improved cornering action of the cart at corners between alleyways.
According to a second aspect of the invention there is provided a cart for carrying an animal through alleyways and around corners in the alleyways comprising:
a cage assembly for containing the animal including a cage floor on which the animal stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the animal so that the animal is maintained extending longitudinally of the cage assembly, a cage front assembly and a cage rear assembly for confining the animal against forward and rearward movement;
the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the animal within the cage assembly;
the ground wheels including two drive wheels each adjacent a respective side of the cart;
a motor for driving the ground wheels for propelling the cart in an alleyway and around corners;
and a drive coupling operable such that in a first position the drive coupling communicates drive to both wheels for propelling the cart in a straight line along an alleyway and such that in a second position the drive coupling communicates drive to only one of the wheels for propelling the cart around a corner.
Preferably the cage assembly is operable to change from a first mode for moving in a straight line along an alleyway to a second mode for negotiating around a corner.
Preferably an operating mechanism operable to change the cage assembly from the first mode to the second mode is arranged to operate the drive coupling from the first position to the second position.
Preferably the cage assembly has a front portion including parts of the cage sides and the front cage assembly for receiving the front feet and forward portion of the animal and a rear portion including parts of the cage sides and the rear cage assembly for receiving the rear feet and rearward portion of the animal and wherein the front portion is connected to the rear portion for pivotal movement about at least one vertical pivot axis to allow the cage assembly to navigate around a corner from one alleyway to another.
Preferably the drive coupling includes a first coupling element for communicating drive from the motor to one of the wheels and a releasable second coupling element operable in a first position to communicate drive to the other of the wheels and in a second position to disconnect drive to the other of the wheels.
Preferably said one of said wheels is connected to a drive axle to which said motor is connected and wherein the releasable second coupling element comprises a disk lying in a radial plane of the axle and connected to said axle and movable axially into and out of connection with an axle portion connected to said other of said wheels.
It is a yet further object of the present invention to provide an improved cart for transporting an animal which is shaped and arranged to allow an improved guiding action of the cart at along alleyways.
According to a third aspect of the invention there is provided a cart for carrying an animal through alleyways comprising:
a cage assembly for containing the animal including: a cage floor on which the animal stands, two cage sides each on a respective side of a longitudinal center line of the cage assembly for confining the animal so that the animal is maintained extending longitudinally of the cage assembly, a cage front assembly, and a cage rear assembly for confining the animal against forward and rearward movement; the cage assembly being mounted on ground wheels for movement generally longitudinally along an alleyway carrying the animal within the cage assembly; and two guide rollers for engaging respective sides of the alleyway; each guide roller being mounted on a respective cage side at a height above the cage floor so as to project outwardly from the cage side; each guide roller being rotatable about a generally upright axis so as to provide a peripheral surface which is arranged to rolls along an abutment along the side of the alleyway; each guide roller being mounted for adjustment of the height thereof from the cage floor; and each guide roller being mounted for adjustment of a distance of the peripheral surface thereof from the cage side.
Preferably each cage side includes a plurality of vertical bars and wherein each guide roller includes a bracket which clamps to two parallel bars so that height adjustment is obtained by moving the bracket along the bars.
Preferably the two parallel bars are mounted on the cage side for pivotal movement about a vertical axis so as to pivot the bracket inwardly and outwardly relative to the cage side.
Preferably the vertical axis is longitudinal of one of the bars so as to pivot the bracket and the other bar inwardly and outwardly relative to the cage side.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described in conjunction with the accompanying drawings in which:
FIG. 1 is an isometric view of a cart according to the present invention showing the cart in the straight ahead position.
FIG. 2 is a top plan view of the cart of FIG. 1 with the cart in its straight ahead position.
FIG. 3 is a top plan view of the cart of FIG. 1 with the cart in its opened position.
FIG. 4 is a top plan view of the cart of FIG. 1 with the cart in its cornering position.
FIGS. 5 and 6 are isometric views of the cage side elements mounting the guide rollers.
FIG. 7 is a bottom plan view of the cart of FIG. 1 in the straight ahead position and showing the drive system including the drive couplings which allow two wheel and one wheel drive.
FIG. 8 is a bottom plan view similar to that of FIG. 7 of the cart of FIG. 1 on an enlarged scale showing only the drive couplings.
DETAILED DESCRIPTION
The embodiment shown in FIGS. 1 through 4 forms a cart 10 for transporting an animal, particularly a boar, through an alleyway.
Many of the features of the cart are shown in the above U.S. Pat. No. 6,196,975 assigned to the present assignee including the general structure of the cage assembly, the ground wheels, the drive system, the guide rollers and the panels which are movable to prevent vision in one or other direction by the animal. As all of these features are clearly described in the above patent, the description is not repeated here for brevity and reference to that prior patent should be made for any details that are omitted herein. The description of the present arrangement hereinafter will therefore concentrate upon the important features of difference from the above patent.
In addition, the above U.S. Pat. No. 6,336,426 shows the construction of a center pivot and an overlying floor arrangement by which the cart is formed in front and rear sections which can pivot relative to one another about a vertical axis for assisting in negotiating corners. The location and arrangement of the pivot axis and the construction by which the pivoting movement is obtained shown in more detail in this patent to which reference can be made for any further details required.
In general, therefore, the cart 10 forms a cage with a floor 11 , a top 12 and upstanding side walls 13 and 14 . The floor 11 is formed in two pieces including a front piece 11 A and a rear piece 11 B and similarly the top is formed in a front piece 12 A and a rear piece 12 B. The top and the floor pieces are interconnected by pivot pins 15 which allow the cart to pivot about a common vertical axis passing through the floor and the top.
The sides of the cage are formed by bars 16 which interconnect the floor and the top. The bars of the rear section are separated from the bars of the front section allowing the cart to pivot about the vertical axis with the side walls expanding or contracting as required depending upon the direction of the pivotal action.
The cart is mounted on ground wheels including drive wheels 17 A and caster wheels 17 B for movement over the ground. Guide rollers 18 at the bottom of the cart at floor level are arranged to contact elements at the alleyway side when necessary to prevent hanging up of the cart. The electrical control system is indicated schematically at 19 and communicates power and control a motor 19 A on the bottom of the floor which drives the ground wheels for forwarding the cart along an alleyway, as described in more detail hereinafter. Remote control to the electrical control system 19 is provided but not shown. The cage includes a cage front assembly 20 attached to a forward end of the side walls 13 and 14 so as to project forwardly therefrom and to bridge thereacross to retain the animal within the cage. In addition the cage assembly includes a rear cage assembly 30 which again extends rearwardly from the side walls and bridges across therebetween to retain the rear of the animal within the cage.
In an alternative arrangement (not shown) the cart including the floor, top and side walls can be formed as a rigid structure substantially of the construction shown in the above patent while utilising the same arrangement of front and rear cage assembly as described herein after.
The front frame assembly 20 comprises two side panels 21 and 22 and a center panel 23 . Each of the side panels includes an open window 24 which can be closed by the application of a cover panel to inhibit the vision of the animal to that one side as described in the above patent.
Each of the side panels 21 and 22 includes a vertical rear edge 25 and a vertical front edge 25 A which are formed by posts. The rear post is mounted on a collar 25 B at a front post 13 A of the side wall 13 . Thus the side panel 22 can pivot side to side by the vertical axis defined by the collar 25 B at the respective cage side. The side panels 21 and 22 are substantially symmetrical except that the side panel 22 carries a guide arm 26 which extends across from the side panel toward the top 12 A where it can be locked by a spring pin 27 to hold the arm 26 in place and therefore to locate the side panel 22 at a predetermined angle relative to the cage side 13 .
The center panel 23 has a width less than the spacing between the cage sides so that in the symmetrical position of the front gate assembly as shown in FIG. 1 and , the side panels 21 and 22 converge forwardly and inwardly in a tapering action.
Each of the side panels includes a bottom rail 28 interconnecting the posts 25 and 25 A. On the bottom of the post 25 A beneath the rail 28 is provided a roller 29 which acts to engage elements in the alleyway at to provide a pushing force on the side panel in a direction away from the engaged elements.
The center panel 23 is formed from a sheet of metal which carries at its vertical side edges a post 23 A on one side and a post 23 B on the opposed side. The post 23 A is pivotally mounted in collars 23 C attached to the post 25 A of the side panel 21 . Thus the center panel 23 is carried on the side panel 21 and can pivot about a vertical axis defined by the collar 23 C at the post 25 A of the side panel 21 . The post 23 B of the center panel 23 can be received within a receptacle 23 D of the post 25 A of the side panel 22 so that it can be latched in place within the receptacle or can be released from the receptacle to allow the front gate assembly to be opened. The receptacle provides a channel which allows the post 23 B to rotate relative to the channel and thus relative to the post 25 A of the side panel 22 .
Thus the front gate assembly can take up a fixed central position located by the pin 27 and the arm 26 in which the side panels are symmetrical and the center panel is at right angles to the normal direction of movement as shown in FIGS. 1 and 2 . The front assembly can also pivot to either side as shown in FIG. 4 . Thus in FIG. 4 the side panel 22 has been pushed across toward the opposite gate side 14 . The side panel 21 is of course also moved across to take up a position in which it is generally aligned with the forward part of the gate side as indicated at 14 A. This movement of the side panels is caused by the pushing action on the roller 29 which causes the side panel 22 to move across the front face of the cage assembly with the side panel 21 being pushed by the center panel 23 . This movement occurs only when the latch pin 27 is released when it is intended that the cage be moved around a narrow corner.
In addition to the side pivoting action of the front gate assembly, the main structure of the cage also pivots about the pivot axis 15 and this pivoting action can be locked by a lever 15 A which holds the cage structure in the straight ahead position until required for cornering.
The rear gate assembly 30 comprises a pair of side panels 31 and 32 which are connected by a link 35 .
Each of the side panels 31 and 32 comprises a first straight section 33 and a second straight section 34 arranged at an angle to the first. Thus as shown in the symmetrical position of FIG. 2 , the first portion 33 extends rearwardly and inwardly at a shallow angle to the cage side and the second portion 34 extends rearwardly and inwardly at a sharper angle to cage side. The side panels 31 and 32 are formed of a post 36 which is attached to the end post 16 of the cage side on collars 36 A. The side panel further includes a rear end post 37 at the end of the second straight section 34 . The posts 36 and 37 are interconnected by a plurality of horizontal rails which define the two straight sections 33 and 34 to the rear post 37 . The link 35 is not a closed sheet or panel in the form of the center panel 23 but is nearly a connecting piece which bridges the upper open ends of the posts 37 . Thus the link forms a U-shaped member with a horizontal cross piece and a pair of vertical legs where each leg extends into an open upper mouth of the respective post 37 .
There is no locking mechanism for the rear gate assembly so that it can pivot side to side but generally remains in the symmetrical position shown in FIGS. 1 and 2 due to the position of the rear end of the boar within the cart.
The three positions of the system are best shown in FIGS. 2 , 3 and 4 . In FIG. 2 , the arrangement is shown in the symmetrical straight ahead position for movement along an alleyway in the manner described in the previous patents. The boar can stand on the floor 11 between a front floor edge 11 C which is located in front of the cage sides and converges forwardly and inwardly to generally an apex 11 D. The apex 11 D is rearward of the front center panel 23 so that the front center panel defines the front of the structure without interference from the floor.
The rear edge of the floor is indicated at 11 E which is again located in front of the rear end of the rear cage assembly and in front of the link 35 so the rear feet of the animal can stand on the floor while the rear end of the animal projects rearwardly into the area in front of the rear gate assembly.
In FIG. 4 is shown the cornering arrangement for cornering around a corner in the narrowest accessible alleyway which is generally 24 inches in width where the cornering action is obtained by the pivot about the center pivot 15 and by sideways movement both of the front cage assembly and the rear cage assembly. In the case of the rear cage assembly, it will be noted that the link 35 allows the rear posts 37 of the side panels 31 and 32 to overlap so that the structure at the rear takes up a very narrow and retracted position pushing against the rear end of the animal.
In FIG. 3 is shown the same construction in the opened condition for loading or unloading of an animal. In this condition the link 35 is separated from one of the posts 37 allowing the rear panels 31 and 32 to pivot apart to open the rear end for entry of the animal into the rear of the cage assembly. Also shown is the opening of the front section in which the post 23 B of the center panel 23 is released from the receptacle 23 D allowing the side panel 21 to be pivoted outwardly to one side for unloading of the animal. Normally of course only one of the front and rear will be opened for loading or unloading as required.
Turning now to FIGS. 5 and 6 , the construction of the forward part of each of the cage sides is shown in more detail. Each of the cage sides includes the front post 16 and a plurality of further vertical bars or posts indicated at 16 A, 16 B and 16 C. In addition a shorter post 16 D is connected to the end post 16 C by horizontal connection pieces 16 E. The short post 16 D bridges the gap between the front section and the rear section to inhibit the animal from escaping between the front and rear sections when turned in a direction to increase the spacing therebetween.
The post 16 A is connected to the post 16 B at the bottom by a horizontal connection piece 16 F and the top by an adjustment plate 16 G. Thus the post 16 B is carried on the post 16 A rather than on the bottom frame 16 H which interconnects the posts 16 and 16 C. At the top the plate 16 G lies underneath a horizontal connection piece 16 J connecting the post 16 and 16 C. A horizontal flange 16 K is connected to the inside surface of the cross member connector piece 16 J. The post 16 A is mounted on a pivot pin carried on the bottom frame 16 H and a similar pivot pin on the cross member 16 J. Thus the post 16 A can rotate about a vertical axis along its length thus moving the post 16 B inwardly and outwardly relative to the cage side. The angular position of the post 16 B relative to the cage side is defined by selecting one of a plurality of holes 16 L in the plate 16 G and locating that hole at the required position by a spring pin 16 M.
On the subassembly defined by the posts 16 A and 16 B is mounted a guide roller 80 which defines a vertical pivot pin 81 allowing rotation of the roller about a vertical axis. This defines therefore a peripheral surface which can roll along a suitable element of the alleyway as the cart moves along the alleyway. The roller 80 and the pin 81 are carried on a bracket 82 which includes a back plate 83 and a pair of horizontal supports plates 84 and 85 which are attached to the back plate 83 . The back plate 83 is attached to the posts 16 A and 16 B by a clamping plate 86 which defines a pair of channels 87 on either side of a plate portion 88 which is fastened to the back plate 83 by bolts 89 . Thus the posts 16 A and 16 B are clamped into the channels 86 and 87 by clamping together the plates 83 and 88 . The height of the roller on the posts can be adjusted simply by releasing the fasteners 89 and sliding the clamping plates upwardly and downwardly along the posts to the height required where the periphery of the roller is located adjacent a suitable element of the alleyway.
The spacing of the outermost point of the peripheral surface of the roller welded to the cage side can be adjusted by rotating the subassembly defined by the posts 16 A and 16 B and the bracket 82 about the longitudinal axis of the posts 16 A.
In operation where the alleyway is wider than the cart, the rollers are adjusted to the required location so that the spacing of the rollers is equal to substantially the width of the alleyway at the suitable abutment to which the height of the roller is adjusted. This adjustment can be effected simply by pulling the spring pin 16 M and rotating the plate 16 G to the required angle.
The cart can be set so that it runs along one side of the alleyway rather than the other by adjusting one of the rollers to a greater distance of spacing from the cage side than the other of the rollers.
Turning now to FIGS. 7 and 8 , the bottom of the cart is shown including the drive wheel 17 A mounted on a hub 17 E and the castor wheel 17 B mounted on the underside of the floor 11 . The drive motor 90 is located on the underside of the floor receiving power from the electrical control system 19 mounted on the top of the cart. The motor 90 drives a sprocket 91 which communicates drive through a chain 92 to a sprocket 93 on an axle 94 carried in bearings 95 and driving one of the wheels 17 A. The other of the wheels indicated at 17 C is mounted on a hub 17 D a stub axle portion 96 carried on the axle 94 and rotatable relative thereto. The stub axle portion 96 carries a disc 97 parallel to a similar disc 98 carried on the axle 94 . A moveable engagement plate 99 is carried between the discs 97 and 98 and is movable side to side by an operating device 100 and caliper 101 . When moved to one side, the disc 99 communicates drive from the disc 98 on the axle 94 to the stub axle 96 thus driving the wheel 17 C. When moved to the other side, the disc 99 is separated from the disc 97 so that the wheel 17 C is free from the axle 94 and thus is not driven by the motor 90 .
The operating device 100 is connected to the lever 15 A on the top of the cart so that when the lever 15 A is operated to release the lock which holds the cart in the straight ahead condition, the lever also operates the device 100 to release the drive coupling to a stub axle 96 . In this way the operator needs to operate only the lever 15 A to release the cart for cornering which also acts simultaneously to release the two-wheel drive driving the wheels 17 A and 17 C so that only the wheel 17 A is driven during the cornering action. The single-wheel drive during cornering prevents the tendency of the two-wheel drive to forward the cart in a straight line direction from interfering with the cornering action.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. | A boar cart for carrying a boar through alleyways of a sow insemination area for interaction with the sows during insemination is formed by a cage for containing the boar which includes a cage floor on which the boar stands, two sides each defined by vertical bars on a respective side of a longitudinal center line of the cage assembly for confining the boar so that the boar is maintained extending longitudinally of the cage, a cage front and a cage rear. The cage may be rigid or may be defined by a front portion and a rear portion connected together for pivotal articulated movement about a pivot coupling defining a vertical pivot axis arranged substantially at the center line such that the cage can articulate to the left and to the right for navigating left and right corners in the alleyways while the boar is retained in the cage. The cage front and cage rear are each defined by two panels pivotally mounted at on end to the cage side and pivotally connected at the other end to a link holds the other ends spaced but which allows the panels to pivot side to side in the corner of a narrow alleyway. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Applicant states that this utility patent application claims priority from U.S. patent application Ser. No. 12/156,476 filed on May 30, 2008 and is a continuation of said utility patent application, which claimed priority from U.S. patent application Ser. No. 11/405,207 filed on Apr. 17, 2006, which claimed priority from both U.S. patent application Ser. No. 10/177,067 filed on Jun. 21, 2002 and Provisional Pat. App. No. 60/697,434 filed on Jul. 9, 2005, all of which are incorporated by reference herein in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to a shaft seal assembly with multiple embodiments. A labyrinth seal for retaining lubrication solution within the bearing cavity of a hub assembly, such as a bearing housing, for application to a rotatable shaft to keep contaminants out of the bearing cavity is disclosed and claimed. In another embodiment, the shaft seal assembly may be used as a product seal between a product vessel and a shaft therein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] No federal funds were used to create or develop the invention herein.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0004] N/A
BACKGROUND OF THE INVENTION
[0005] For years there have been a multitude of attempts and ideas for providing a satisfactory seal when a rotatable shaft is angularly misaligned resulting in run out of the shaft. Typically the solutions presented have failed to provide an adequate seal while allowing for an acceptable amount of shaft misalignment during operation. The problem is especially acute in product seals where the potential for shaft to bore misalignment may be maximized. A typical solution in the prior art is to increase the operating clearance between the rotating shaft and sealing members to create a “loose” clearance or operating condition. “Loose” running for adjustment or response to operational conditions, especially misalignment of the shaft with respect to the stator or stationary member, however, typically reduces or lowers the efficiency and efficacy of sealing members.
[0006] Labyrinth seals, for example, have been in common use for many years for application to sealing rotatable shafts. A few of the advantages of labyrinth seals over contact seals are increased wear resistance, extended operating life and reduced power consumption during use. Labyrinth seals, however, also depend on a close and defined clearance with the rotatable shaft for proper function. Shaft misalignment is also a problem with “contact” seals because the contact between the seal and misaligned shaft typically results in greater wear. Abrasiveness of the product also affects the wear pattern and the useful life of the contact seals.
[0007] Prior attempts to use fluid pressure (either vapor or liquid) to seal both liquid and solid materials in combination with sealing members such as labyrinth seals or contact seals have not been entirely satisfactory because of the “tight” or low clearance necessary to create the required pressure differential between the seal and the product on the other side of the seal (i.e., the tighter the seal, the lower the volume of fluid required to maintain the seal against the external pressure of material.) Another weakness in the prior art is that many product seals expose the movable intermeshed sealing faces or surfaces of the product seal to the product resulting in aggressive wear and poor reliability. Furthermore, for certain applications, the product seal may need to be removed entirely from the shaft seal assembly for cleaning, because of product exposure to the sealing faces or surfaces.
[0008] The prior art then has failed to provide a solution that allows both a “tight” running clearance between the seal members and the stationary member for efficacious sealing and a “loose” running clearance for adjustment or response to operational conditions especially misalignment of the rotatable shaft with respect to the stator or stationary member.
SUMMARY OF THE INVENTION
[0009] The present art offers improved shaft sealing and product seal performance over the prior art. The shaft seal assembly solution disclosed and claimed herein allows both tight or low running clearance between seal members and the stationary member and a loose running clearance for adjustment or response to operational conditions especially misalignment of a rotatable shaft with respect to the stator or stationary member.
[0010] As disclosed herein, the present art describes and provides for improved function by allowing a labyrinth seal to adjust to radial, axial and angular movements of the shaft while maintaining a desired shaft-to-labyrinth clearance. The present art also permits equalization of pressure across the labyrinth pattern by permitting venting and thus improved function over currently available designs. Additionally, sealing fluid (air, steam, gas or liquid) pressure may be applied through the vent or port locations to establish an internal seal pressure greater than inboard or outboard pressure (over-pressurization). This enables the labyrinth to seal pressure differentials that may exist between the inboard and outboard sides of the seal. Pressurization of the internal portion of the shaft seal assembly effectively isolates the moving or engaging faces of the shaft seal assembly from contact with product by design and in combination with a pressurized fluid barrier.
[0011] It is therefore an object of the present invention to provide a shaft seal assembly for engagement with a housing which maintains its sealing integrity with a shaft upon application of axial, angular or radial force upon said shaft.
[0012] It is another object of the present invention to provide a shaft seal assembly, which may be mounted to a vessel wall for engagement with a shaft which maintains its sealing integrity with a shaft during or in response to axial, angular or radial force movement of said shaft.
[0013] Other objects and features of the invention will become apparent from the following detailed description when read with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective exterior view of the shaft seal assembly.
[0015] FIG. 2 is an exterior end view of the shaft seal assembly with the shaft element aligned.
[0016] FIG. 3 is a sectional view of a first embodiment of the shaft seal assembly, as shown in FIG. 2 and mounted to a housing.
[0017] FIG. 3A illustrates the first surface seal-shaft integrity during angular and radial shaft alignment.
[0018] FIG. 3B illustrates second surface seal-shaft integrity during angular and radial shaft alignment.
[0019] FIG. 4 is an exterior end view with the shaft misaligned.
[0020] FIG. 5 is a sectional view of the first embodiment as shown in FIG. 3 with both angular and radial misalignment of the shaft applied.
[0021] FIG. 5A illustrates first seal-shaft integrity allowed by articulation during angular and radial shaft misalignment.
[0022] FIG. 5B illustrates second seal-shaft integrity allowed by articulation during angular and radial shaft misalignment.
[0023] FIG. 6 is a sectional view of a second embodiment of the shaft seal assembly as shown in FIG. 2 .
[0024] FIG. 7 is a sectional view of a third embodiment as shown in FIG. 2 .
[0025] FIG. 8 is a perspective view of a fourth embodiment as mounted to a vessel wall.
DETAILED DESCRIPTION—ELEMENT LISTING
[0026]
[0000]
Description
Element No.
Shaft
1
Fixed stator
2
Fixed stator (part-line)
2a
Labyrinth seal
3
Radiused face
3a
Floating stator
4
Fluid return pathway
5
Shaft seal clearance
6
First o-ring
7
Anti-rotation pin
8
Vent
9
Anti-rotation groove (floating stator)
10
Spherical interface
11
Anti-rotation pin
12
Second o-ring
13
Labyrinth seal pattern grooves
14
First o-ring channel
15
Cavity for anti-rotation device (fixed stator)
16
Axial face of labyrinth seal
17
Axial face of floating stator
18
Second o-ring channel
19
First clearance between floating stator/fixed stator
20
Second clearance between floating stator/fixed stator
21
Throttle groove
22
Labyrinth pattern annular groove
23
Sleeve
24
Shaft seal assembly
25
Throttle (alignment skate)
26
Floating stator annular groove
27
Labyrinth seal passage
28
Floating stator passage
29
Housing
30
Angle of misalignment
31
Bearings and bearing cavity
32
Mounting bolts
33
Vessel wall
34
DETAILED DESCRIPTION
[0027] FIGS. 1-5 provide a view of a first embodiment of the shaft seal assembly 25 that allows for sealing various lubricating solutions within bearing housing 30 . FIGS. 6 and 7 provide alternative embodiments of the shaft seal assembly 25 wherein sealing fluids are used. Applicant herein defines sealing fluids to include both liquids and vapors. Applicant considers air, nitrogen, water and steam as well as any other fluid which may work with the proposed shaft seal assembly to provide a pressurized fluid barrier for any and all embodiments disclosed herein to be within the purview of the present disclosure. The gas or fluid chosen is based on process suitability with the product to be sealed.
[0028] FIG. 1 is a perspective exterior view of the shaft seal assembly 25 arranged and engaged with a shaft 1 inserted through the fixed stator 2 of shaft seal assembly 25 . FIG. 2 is an exterior end view of the shaft seal assembly with shaft 1 aligned within the shaft seal assembly 25 .
[0029] FIG. 3 is a sectional view of a first embodiment of the shaft seal assembly 25 shown in FIG. 2 illustrating the shaft seal assembly 25 as a labyrinth seal for retaining lubrication solution within the bearing cavity 32 of housing 30 . The shaft 1 shown in FIG. 3 is the type which may experience radial, angular or axial movement relative to the fixed stator element or portion of the fixed stator 2 during rotation. The fixed stator portion of the shaft seal assembly 25 may be flange-mounted or press-fit or attached by other means to a housing 30 . The invention will also function with a rotating housing and stationary shaft. (Not shown) As required by the particular application, the shaft 1 is allowed to move freely in the axial direction in relation to the shaft seal assembly 25 .
[0030] A labyrinth seal 3 having an interior surface is engaged with shaft 1 . A defined clearance 6 exists between the interior surface of said labyrinth seal 3 and the shaft 1 . Opposite the interior surface of said labyrinth seal 3 is the radiused surface 3 a of said labyrinth seal 3 . The radiused surface 3 a of the labyrinth seal 3 and the interior of the floating stator 4 forms a spherical interface 11 . O-ring channels 15 and o-rings 7 are disposed to cooperate with said radiused surface 3 a of said labyrinth seal 3 to seal (or trap) fluid migration through, between and along engaged labyrinth seal 3 and floating stator 4 while maintaining spherical interface 11 which allows limited relative rotational movement (articulation) between labyrinth seal 3 and floating stator 4 . O-ring channels 15 , as shown, are machined into the floating stator 4 and positioned at the spherical interface 11 with labyrinth seal 3 . O-ring channels 15 are annular and continuous in relation to labyrinth seal 3 . The o-ring channel 15 and o-ring 7 may also be placed in the labyrinth seal 3 adjacent the spherical interface 11 . O-rings 7 should be made of materials that are compatible with both the product to be sealed and the preferred sealing fluid chosen. O-ring channels 15 and o-rings 7 are one possible combination of sealing means that may be used within the shaft seal assembly 25 as recited in the claims. Strategically placed anti-rotation pin(s) 12 inserted into anti-rotation grooves 10 limit relative rotational movement between labyrinth seal 3 and floating stator 4 . A plurality of anti-rotation grooves 10 and pins 12 may be placed around the radius of the shaft 1 . If the shaft seal assembly 25 is used in combination with a sealing fluid, strategic anti-rotation pins 12 may be removed allowing corresponding anti-rotation grooves 10 to serve as a fluid passage through vent 9 and lubricant return 5 . (See FIG. 7 ) Additionally, the relationship of the diameters of anti-rotation pins 12 and anti-rotation grooves 10 may be selected to allow more or less angular misalignment of the shaft 1 . A small diameter anti-rotation pin 12 used with a large diameter anti-rotation groove 10 would allow for greater relative movement of the labyrinth seal 3 in relation to the floating stator 4 in response to angular misalignment of shaft 1 . Labyrinth seal 3 is one possible embodiment of a sealing means that may be used adjacent to the shaft 1 within the shaft seal assembly 25 as recited in the claims.
[0031] A continuous annular channel is formed within fixed stator 2 and defined by clearance 20 and 21 as allowed between the exterior of said floating stator 4 and said interior of said fixed stator 2 of shaft seal assembly 25 . The annular channel of fixed stator 2 is highlighted as A-A′ in FIG. 2 . The annular channel of the fixed stator has interior surfaces which are substantially perpendicular to said shaft 1 . The exterior surfaces of the floating stator 4 , which is substantially encompassed within the annular channel of the fixed stator 2 , cooperatively engage with the first and second interior perpendicular faces of the fixed stator 2 . An inner annular interface is formed by the first (shaft seal assembly inboard side) perpendicular annular channel surface of the fixed stator 2 engaging with the first (inboard side) perpendicular face of the floating stator 4 . An outer annular interface is formed by the second (shaft seal assembly outboard side) perpendicular annular interior channel surface of the fixed stator 2 engaging with the second (outboard side) perpendicular face of the floating stator 4 . O-ring channels 19 and o-rings 13 disposed therein cooperate with the surfaces of floating stator 4 which are in perpendicular to relation to shaft 1 to seal (or trap) fluid migration between and along engaged floating stator 4 while allowing limited relative rotational movement between floating stator 4 and fixed stator 2 . Floating stator 4 and fixed stator 2 are one possible embodiment of cooperatively engaged sealing means that may be used in combination with labyrinth seal 3 within the shaft seal assembly 25 as recited in the claims.
[0032] O-ring channels 19 are annular and continuous in relation to shaft 1 . The o-ring channels 19 and o-rings 13 may be placed in the body of the floating stator 4 instead of the fixed stator 2 (not shown) but must be placed in similar proximal relation. O-rings 13 should be made of materials that are compatible with both the product to be sealed and the preferred sealing fluid chosen. O-ring channels 19 and o-rings 13 are one possible combination of sealing means that may be used within the shaft seal assembly 25 as recited in the claims.
[0033] Strategically placed anti-rotation pin(s) 8 inserted into anti-rotation groove(s) 16 limit both relative radial and rotational movement between floating stator 4 and interior side of fixed stator 2 . A plurality of anti-rotation grooves 16 and pins 8 may be placed around the radius of the shaft 1 . The relationship of the diameters of anti-rotation pins 8 and anti-rotation grooves 16 may also be selected to allow more or less angular misalignment of the shaft. A small diameter anti-rotation pin 8 and large diameter fixed stator anti-rotation groove allow for greater relative movement of the labyrinth seal 3 in response to angular misalignment of shaft 1 .
[0034] The labyrinth pattern seal grooves 14 may be pressure equalized by venting through one or more vents 9 . If so desired, the vents may be supplied with a pressurized sealing fluid to over-pressurize the labyrinth area 14 and shaft seal clearance 6 to increase the efficacy of shaft seal assembly 25 . A spherical interface 11 between the labyrinth seal 3 and the floating stator 4 allow for angular misalignment between the shaft 1 and fixed stator 2 . O-ring channels 19 are annular with the shaft 1 and, as shown, are machined into the fixed stator 2 and positioned at the interface between the fixed stator 2 and floating stator 4 . O-ring channel 19 may also be placed in the floating stator 4 for sealing contact with the fixed stator 2 .
[0035] FIG. 3A illustrates seal-shaft integrity during angular and radial shaft alignment. This view highlights the alignment of the axial face 17 of the labyrinth seal 3 and the axial face 18 of the floating stator 4 . Particular focus is drawn to the alignment of the axial faces 17 and 18 at the spherical interface 11 between the floating stator 4 and labyrinth 3 . FIG. 3B illustrates the shaft-seal integrity during angular and radial shaft alignment at the surface opposite that shown in FIG. 3A . This view highlights the alignment of the axial faces 17 and 18 of labyrinth seal 3 and floating stator 4 , respectively, for the opposite portion of the shaft seal assembly 25 as shown in FIG. 3A . Those practiced in the arts will appreciate that because the shaft 1 and shaft seal assembly 25 are of a circular shape and nature, the surfaces are shown 360 degrees around shaft 1 . Again, particular focus is drawn to the alignment of the axial faces 17 and 18 at the spherical interface 11 between the labyrinth seal 3 and floating stator 4 . FIGS. 3A and 3B also illustrate the first defined clearance 20 between the floating stator 4 and the fixed stator 2 and the second defined clearance 21 between the floating stator 4 and fixed stator 2 and opposite the first defined clearance 20 .
[0036] In FIGS. 2 , 3 , 3 A and 3 B, the shaft 1 is not experiencing radial, angular or axial movement and the width of the defined clearances 20 and 21 , which are substantially equal, indicate little movement or misalignment upon the floating stator 4 .
[0037] FIG. 4 is an exterior end view of the shaft seal assembly 25 with the rotatable shaft 1 misaligned therein. FIG. 5 is a sectional view of the first embodiment of the shaft seal assembly 25 as shown in FIG. 3 with both angular and radial misalignment of the shaft 1 applied. The shaft 1 as shown in FIG. 5 is also of the type which may experience radial, angular or axial movement relative to the fixed stator 2 portion of the shaft seal assembly 25 .
[0038] As shown at FIG. 5 , the defined radial clearance 6 of labyrinth seal 3 with shaft 1 has been maintained even though the angle of shaft misalignment 31 has changed. The shaft 1 is still allowed to move freely in the axial direction even though the angle of shaft misalignment 31 has changed. The arrangement of the shaft seal assembly 25 allows the labyrinth seal 3 to move with the floating stator 4 upon introduction of radial movement of said shaft 1 . The labyrinth seal 3 and floating stator 4 are secured together by one or more compressed o-rings 7 . Rotation of the labyrinth seal 3 within the floating stator 4 is prevented by anti-rotation means which may include a screws, pins or similar devices 12 to inhibit rotation. Rotation of the labyrinth seal 3 and floating stator 4 assembly within the fixed stator 2 is prevented by anti-rotation pins 8 . The pins as shown in FIGS. 3 , 3 A, 3 B, 5 , 6 and 7 are one means of preventing rotation of the labyrinth seal 3 and floating stator 4 , as recited in the claims. Lubricant or other media to be sealed by the labyrinth seal 3 may be collected and drained through a series of one or more optional drains or lubricant return pathways 5 . The labyrinth seal 3 may be pressure equalized by venting through one or more vents 9 . If so desired, the vents 9 may be supplied with pressurized air or other gas or fluid media to over-pressurize the labyrinth seal 3 to increase seal efficacy. The combination of close tolerances between the cooperatively engaged mechanical portions of the shaft seal assembly 25 and pressurized sealing fluid inhibit product and contaminate contact with the internals of the shaft seal assembly 25 . The spherical interface 11 between the labyrinth seal 3 and the floating stator 4 allow for angular misalignment between the shaft 1 and fixed stator 2 . O-ring channel 19 and o-ring 13 disposed therein cooperate with the opposing faces of the floating stator 4 , which are substantially in perpendicular relation to shaft 1 , to seal (or trap) fluid migration between and along engaged floating stator 4 while allowing limited relative radial (vertical) movement between stator 4 and fixed stator 2 .
[0039] FIG. 5A illustrates seal-shaft integrity allowed by the shaft seal assembly 25 during angular and radial shaft misalignment. This view highlights the offset or articulation of the axial faces 17 of the labyrinth seal in relation the axial faces 18 of the floating stator 4 for a first portion of the shaft seal assembly 25 . Particular focus is drawn to the offset of the axial faces 17 and 18 at the spherical interface 11 between labyrinth seal 3 and floating stator 4 .
[0040] FIG. 5B illustrates seal-shaft integrity for a second surface, opposite the first surface shown in FIG. 5A , during angular and radial shaft misalignment. This view highlights that during misalignment of shaft 1 , axial faces 17 and 18 , of the labyrinth seal 3 and floating stator 4 , respectively, are not aligned but instead move (articulate) in relation to each other. The shaft to seal clearance 6 is maintained in response to the shaft misalignment and the overall seal integrity is not compromised because the seal integrity of the floating stator 4 to fixed stator 2 and the floating stator 4 to labyrinth seal 3 are maintained during shaft misalignment. Those practiced in the arts will appreciate that because the shaft 1 and shaft seal assembly 25 are of a circular shape and nature, the surfaces are shown 360 degrees around shaft 1 .
[0041] FIGS. 5A and 5B also illustrate the first clearance or gap 20 between the floating stator 4 and the fixed stator 2 and the second clearance or gap 21 between the floating stator 4 and fixed stator 2 and opposite the first clearance or gap 20 .
[0042] In FIGS. 4 , 5 , 5 A and 5 B, the shaft 1 is experiencing radial, angular or axial movement during rotation of the shaft 1 and the width of the gaps or clearances 20 and 21 , have changed in response to said radial, angular or axial movement. (Compare to FIGS. 3 , 3 A and 3 B.) The change in width of clearance 20 and 21 indicate the floating stator 4 has moved in response to the movement or angular misalignment of shaft 1 . The shaft seal assembly 25 allows articulation between axial faces 17 and 18 , maintenance of spherical interface 11 and radial movement at first and second clearance, 20 and 21 , respectively, while maintaining shaft seal clearance 6 .
[0043] FIG. 6 is a sectional view of a second embodiment of the shaft seal assembly 25 as shown in FIG. 2 for over-pressurization with alternative labyrinth seal pattern grooves 14 . In this figure the labyrinth seal pattern grooves 14 are composed of a friction reducing substance such as polytetrafluoroethylene (PTFE) that forms a close clearance to the shaft 1 . PTFE is also sometimes referred to as Teflon® which is manufactured and marketed by Dupont. PTFE is a plastic with high chemical resistance, low and high temperature capability, resistance to weathering, low friction, electrical and thermal insulation, and “slipperiness.” The “slipperiness” of the material may also be defined as lubricous or adding a lubricous type quality to the material. Carbon or other materials may be substituted for PTFE to provide the necessary sealing qualities and lubricous qualities for labyrinth seal pattern grooves 14 .
[0044] Pressurized sealing fluids are supplied to over-pressurize the lubricious labyrinth pattern 26 as shown in FIG. 6 . The pressurized sealing fluids make their way into the annular groove 23 of the throttle 26 through one or more inlets. Throttle 26 is also referred to as “an alignment skate” by those practiced in the arts. Throttle 26 allows the labyrinth seal 3 to respond to movement of the shaft caused by the misalignment of the shaft 1 . The pressurized sealing fluid escapes past the close clearance formed between the shaft 1 and labyrinth seal 3 having throttle 26 . The close proximity of the throttle 26 to the shaft 1 also creates resistance to the sealing fluid flow over the shaft 1 and causes pressure to build-up inside the annular groove 23 . Floating annular groove 27 in cooperation and connection with annular groove 23 also provides an outlet for excess sealing fluid to be “bled” out of shaft seal assembly 25 for pressure equalization or to maintain a continuous fluid purge on the shaft sealing assembly 25 during operation. An advantage afforded by this aspect of the shaft sealing assembly 25 is its application wherein “clean-in place” product seal decontamination procedures are preferred or required. Examples would include food grade applications.
[0045] FIG. 7 illustrates shaft seal assembly 25 with the anti-rotation pin 12 removed to improve visualization of the inlets. These would typically exist, but are not limited to, a series of ports, inlets or passages about the circumference of the shaft seal assembly 25 . FIG. 7 also shows the shape and pattern of the labyrinth seal 3 may be varied. The shape of throttles 26 may also be varied as shown by the square profile shown at throttle groove 22 in addition to the circular-type 26 . Also note that where direct contact with the shaft 1 is not desired, the shaft seal assembly 25 be used in combination with a separate sleeve 24 that would be attached by varied means to the shaft 1 .
[0046] FIG. 8 shows that another embodiment of the present disclosure wherein the shaft seal assembly 25 has been affixed to a vessel wall 34 . The shaft seal assembly 25 may be affixed to vessel wall 34 through securement means such as mounting bolts 33 to ensure improved sealing wherein shaft 1 is subjected to angular misalignment. The mounting bolts 33 and slots (not numbered) through the shaft seal assembly 25 exterior are one means of mounting the shaft seal assembly 25 , as recited in the claims.
[0047] Having described the preferred embodiment, other features of the present invention will undoubtedly occur to those versed in the art, as will numerous modifications and alterations in the embodiments of the invention illustrated, all of which may be achieved without departing from the spirit and scope of the invention. | A shaft seal assembly for maintaining a seal during shaft misalignment comprising a first sealing means adjacent said shaft with a defined clearance between said shaft and said sealing means, said shaft moveable axially in relation to said first sealing means; a second sealing means, said first sealing means partially encompassed within second sealing means and in cooperative communication with said second sealing means; a third sealing means, said second sealing means partially encompassed within third sealing means and in cooperative communication with said third sealing means, said third sealing means attached to said housing or vessel and allowing said first sealing means and second sealing means to cooperatively respond to said forces produced by angular misalignment of said shaft during rotation of said shaft while maintaining defined clearance between said shaft and said sealing means. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A “SEQUENCE LISTING”
[0003] Not applicable.
BACKGROUND OF THE INVENTION
Field of the Invention
[0004] This invention relates generally to image acquisition for automated systems and more particularly to an image acquisition camera system that uses a range sensor to maintain focus, which range sensor operates at a wavelength to which the image acquisition camera is sensitive.
[0005] The automated inspection of moving parts such as printed circuit boards relies heavily on the computer analysis of images created by digital or analog cameras that photograph the parts. In order to accurately analyze moving parts, the motion of the parts must be frozen to reduce blurring and to make accurate measurements. Stroboscopic light sources are known to be useful for this purpose as are fast shutters, either mechanical or electronic. A number of types of stroboscopic light sources are known for use in machine vision applications including coaxial illumination sources that direct the stroboscopic illumination through the same lens as is used by the camera, diffuse illumination that may be provided by a ring shaped light source surrounding the objective lens or the object being viewed, and back illumination that is generated from behind the object.
[0006] While it is possible to dynamically determine the distance from a camera to an object in a number of ways, it is desirable to do so using light that passes through the objective lens that the camera used to acquire the images. Furthermore, there are advantages to using a range sensor, such as a laser range sensor that uses light having a wavelength to which the camera used in the inspection system is sensitive. This approach permits the camera to be used for aligning the range sensor and makes it possible to ensure that the range sensor is properly aligned at the same location on the object being viewed as the camera. Similarly, coaxial illumination is widely preferred and through-the-lens coaxial illumination is most desirable.
[0007] The combination of all of these desirable features creates conflicts. The range sensor ideally will operate continuously, since in many applications the object being viewed is moving continuously rather than in a step-wise fashion. While the instantaneous variation of the distance between the camera and the object being viewed may be relatively small, the long term variation may be large, and consequently it is necessary to adjust the camera-to-object distance to maintain adequate focus. Preferably, the adjustment is made more or less continuously so that it may be made smoothly.
[0008] A problem arises from these competing requirements in that if the range sensor, which relies on light that is visible to the camera, operates at the same time that the camera is acquiring an image, the light from the range sensor will obscure part of the image. Heretofore, one approach to this problem has been to use off-axis, range-sensing lasers, and triangulation to monitor the distance from the camera to the object and thereby avoid having the light enter the camera. Another approach has been to use a laser-range-finding device mounted perpendicular to the measurement surface and a plurality of cameras mounted at angles to the surface.
BRIEF SUMMARY OF THE INVENTION
[0009] Briefly stated and in accordance with a presently preferred embodiment of the invention, apparatus for sequentially imaging an object while maintaining focus includes a camera having a selectable image capture mode, an objective lens optically coupled to the camera, an optical range sensor operating through the objective lens, a strobe illuminator, and a controller coupled to the camera, the illuminator and the range sensor sequentially activating and deactivating the range sensor, selecting and deselecting the image capture mode only when the range sensor is deactivated, and activating and deactivating the strobe illuminator only when the image capture mode is active.
[0010] In accordance with another aspect of the invention the apparatus includes a focus controller coupled to the range sensor for maintaining the object in focus.
[0011] In accordance with still further aspects of the invention the illuminator comprises a coaxial illuminator, a diffuse illuminator, or a back illuminator.
[0012] In accordance with yet another aspect of the invention the coaxial illuminator illuminates the object through the objective lens.
[0013] In accordance with a still further aspect of the invention the camera is either an analog or digital camera and includes a shutter which may be a mechanical shutter.
[0014] In accordance with a still further aspect of the invention the camera has a sensor such as a CCD sensor that is characterized by an integration period and that has a reset function.
[0015] In accordance with one aspect of the invention the shutter is opened for a period less than the integration period and the optical range sensor is activated while the shutter is closed.
[0016] The novel aspects of the invention are set forth with particularity in the appended claims. The invention itself together with further objects and advantages thereof may be more readily understood by reference to the following detailed description of the invention taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0017] FIG. 1 is a schematic drawing of the apparatus in accordance with the invention; and
[0018] FIG. 2 is a timing diagram showing the sequence of operation of the elements of the invention shown in FIG. 1 ; and
[0019] FIG. 3 is a graphical representation showing the object contour, the range sensor output, and the focus position superimposed over the object contour.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring now to FIG. 1 , apparatus for sequentially imaging an object while maintaining focus is shown in diagramatic form. The apparatus indicated generally at 10 includes a camera platform 12 , a sequencing controller 14 , and a focus controller 16 .
[0021] A camera 20 which is preferably a high resolution camera having a solid-state image sensor producing either an analog or digital output signal is mounted on camera platform 12 . Preferably, camera 20 acquires an image of an object 22 being viewed through an objective lens 24 . The object being viewed is shown mounted on a movable stage 26 oriented perpendicular to the optical axis of the camera 20 and the objective lens 24 . While it is preferred that the stage 26 move relative to the camera platform, it should be understood that the camera platform could move relative to the stage or both could move.
[0022] As can be seen, the object 22 being viewed has an irregular surface such that the distance between the camera and the surface varies as the object 22 is moved by the stage 26 . The extent of the irregularities is exaggerated somewhat in FIG. 1 . A typical application for apparatus in accordance with this invention is the inspection of printed circuit boards. Printed circuit boards may be warped or have irregularities on the surface caused by the formation of metal traces, the weight of the components mounted to the board, or the board's own weight. Moreover, the differences in the coefficients of thermal expansion of the various layers of the board and the like may cause potato-chip-like warping. The printed circuit board may also be mounted on stage 26 in a tilted way that causes the distance from the camera to the surface of the printed circuit board to vary as the stage moves. This invention compensates for all of these effects.
[0023] An illuminator 32 , preferably a coaxial illuminator, is mounted on the camera platform and directs an illumination beam 34 towards the surface of the object 22 being viewed by way of a first beam splitter 30 . Beam splitter 30 allows the image being acquired to pass through the beam splitter 30 while at the same time reflecting illumination from the coaxial illuminator to the surface of the object 22 being viewed. This arrangement ensures that the light beam from the illuminator impinges on the surface of the object being viewed at the location being imaged by the camera 20 .
[0024] While a coaxial illuminator arranged as described is presently preferred, other types of illuminators may be employed, either alone or in combination with one another. For example, a diffuse illuminator in the form of a ring light 13 , either surrounding the object being viewed or mounted on the camera platform and surrounding the objective lens, may be employed either alone, or together with the coaxial illuminator. Various types of ring lights may be employed such as lights having white light sources or lights having red, green, and blue light sources that are combined to produce a substantially white light. In specialized applications colors other than white may be used where desired.
[0025] Alternatively, depending upon the nature of the object being viewed, a back illuminator 15 providing light from behind the object being viewed may be employed.
[0026] As the object being viewed is translated with respect to the camera platform, and the surface irregularities or warping move the surface of the object being viewed closer to or farther from the camera, and as any tilt or slope in the object being viewed changes the distance from the camera, it is desirable to adjust the distance from the camera to the surface of the object being viewed to maintain optimum focus.
[0027] In accordance with one aspect of this invention the device is maintained in focus by moving the camera platform 12 with respect to the object being viewed. This adjustment may be made by moving the entire platform, or by other methods of maintaining focus. It will be understood that the distance from the camera to the surface of the object may be adjusted by moving either the camera or the object or both.
[0028] Preferably the distance between the camera and the surface of the object being viewed is measured substantially continuously by a range sensor 36 . Range sensor 36 , which is preferably a laser range sensor, emits a beam of light 17 that is reflected through the objective lens 24 by a second beam splitter 38 . The range sensor beam is reflected from the surface of the object being viewed back through the objective lens, off the surface of the beam splitter 38 , and back to the range sensor 36 , which measures the distance in a manner well known to those skilled in the art. While a laser range sensor is presently preferred, as used in connection with this invention range sensor is intended to be interpreted more broadly to include any sensor that permits a focused position to be acquired and maintained. For example, linear and nonlinear sensors are intended to be included along with sensors that provide a signal that indicates either the magnitude, or the magnitude and direction of the deviation from the sharply focused position.
[0029] In accordance with a presently preferred embodiment of the invention, a beam splitter 38 is provided that reflects virtually all red light back to the range sensor but transmits the rest of the light through the optics to the camera. Using a light source having a non red component, such as an orange light emitting diode, permits gathering a much higher percentage of the light back to the optics than if a neutral density beam splitter and a white light were used. It also allows for the elimination of the use of infrared filters at or near the camera since the beam splitter already blocks the infrared light. Infrared filters have been used in machine vision cameras to block stray infrared light entering the system from uncontrolled sources which degrade imaging performance.
[0030] Preferably, the range sensor produces a signal 21 that is a measure of the deviation of the actual distance from the optimum focus distance and provides that error signal 21 to a focus controller 16 , which adjusts the position of the camera platform 12 to maintain optimum focus. The range sensor signal 21 can also be used for measuring the height variation of the object while gathering images.
[0031] It is preferred that the light beam produced by the range sensor 36 have a wavelength that permits it to be detected by the camera 20 so that the camera can be used to ensure that the range sensor beam is within the area being imaged so as to maintain the best possible focus. By using a range sensor beam that can be imaged by the camera the range sensor can be adjusted by viewing the image produced by the camera and setting the range sensor beam so that it impinges upon the surface of the object being viewed at or near the center of the image being acquired. While laser range sensors are preferred, nonlaser range sensors utilizing white light or lights of other colors may also be employed.
[0032] Each of camera 20 , illuminators 32 , 13 , 15 and range sensor 36 is provided with a control input 40 , 42 , 46 , 48 and 44 respectively. Input 40 controls the operation of camera 20 by switching the camera between a first mode for capturing an image and the second mode for which image capture is inhibited. The manner of switching the camera depends upon the nature of the sensor provided in the camera, but where a CCD sensor is provided the camera may be switched between an image capture mode and a standby mode by adjusting the bias to the CCD sensor.
[0033] This paragraph seems redundant to the next paragraph; the following paragraph seems clearer.]The control inputs 40 , 42 , 44 , 46 , and 48 are connected to controller 14 . Controller 14 selects and deselects the camera image capture mode, turns the illuminators, 13 , 15 , and 32 on and off, and activates and deactivates the range sensor 36 . FIG. 2 is a timing diagram showing the operation of controller 14 .
[0034] While as described, various types of range sensors may be employed in the practice of this invention, visible light range sensors, either white light emitting sources, or colored sources that produce visible light, are presently preferred. Visible light range finders are visible to the camera and allow the rangefinder beam to be easily centered in the camera's field of view. Visible light range sensors such as white light or even visible red light are also preferred over wavelengths outside the visible region so that users are aware of the presence of the range sensor light, which might otherwise be damaging to the eye of the user and not visible.
[0035] Cameras responsive to visible light are presently preferred because they produce an image, which, if viewed directly, looks like what the user would expect to see.
[0036] Referring to FIG. 2 , which is not drawn to scale, the range sensor 36 is activated substantially continuously, except when image capture is actually taking place. The period of time during which the range sensor is activated may be substantially greater than appears from the drawing because of the scale. It is desirable in accordance with this invention that the range sensor be activated for as much of the time as possible. However, the range sensor is deactivated periodically to allow an image to be captured. Alternatively, the range sensor may be activated intermittently as the stage 26 positions the object 22 at locations where image capture is desired.
[0037] Camera 20 is placed in the image capture mode shortly after range sensor 36 is deactivated. Preferably, sufficient time is allowed to elapse between the time the range sensor 36 is deactivated and the time that the camera 20 is placed into the image acquisition mode so that substantially no light from the range sensor will be detected by the camera.
[0038] A short time after the camera is placed in the image capture mode by the application of an appropriate signal to input 40 , strobed illuminator 32 is activated by a signal 42 and the strobed illuminator flashes. The ring light 13 may also be strobed by signal 46 at the same time as strobe iluminator 32 . The camera 20 acquires an image during the period that the strobed illuminator 32 is on and integrates that image during a period commencing when the strobed illuminator turns on, and ending when the camera is deactivated. Following deactivation of the camera the range sensor 36 is again activated and remains on until the next image is acquired.
[0039] Motion controller 14 controls the position of a stage 26 by supplying an actuator signal 50 to the actuator 56 and receiving a position signal 52 from the actuator. Preferably, controller 14 initiates image capture at specific predetermined positions along the path of stage 26 . The predetermined positions may be equally spaced or spaced in accordance with predetermined criteria to capture images at desired locations. As already discussed, it is preferred that the range sensor operate substantially continuously, but if the range sensor is set to operate intermittently then the range sensor is activated as the stage approaches each of the predetermined positions. Once the range sensor is activated controller 14 activates the stroboscopic illuminator and the camera in the manner and sequence described above.
[0040] FIG. 3 is a graphical representation showing the object contour, the range sensor output, and the focus position superimposed over the object contour. As can be seen, the range sensor output is periodically interrupted during image acquisition. By integrating the range sensor output as described above the focus position can be maintained relatively accurately with respect to the actual object contour as shown in the graph.
[0041] While it is preferred to utilize cameras that have reset capability in accordance with this invention, the invention also permits the use of cameras without reset capability. Such cameras are preferably configured to capture a continuous sequence of images in a plurality of camera frames separated by vertical refresh intervals. Controller 14 receives a signal 54 from the camera indicating the state of the camera, that is whether the camera is in an image capture frame or a vertical refresh interval. The stroboscopic illuminator is sequenced by controller 14 to operate during every frame or during preselected camera frames and is inhibited from operating during vertical refresh intervals when no image can be acquired by the camera.
[0042] While the invention has been described in accordance with a presently preferred embodiment thereof, those skilled in the art will recognize that various modifications and changes may be made in the invention without departing from the true spirit and scope thereof, which accordingly is intended to be defined solely by the appended claims. | Apparatus for sequentially imaging an object while maintaining focus includes a camera having a selectable image capture mode, an objective lens optically coupled to the camera, an optical range sensor operating through the objective lens, a strobe illuminator, and a controller coupled to the camera, the illuminator and the range sensor sequentially activating and deactivating the range sensor, selecting and deselecting the image capture mode only when the range sensor is deactivated, and activating and deactivating the strobe illuminator only when the image capture mode is active. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of U.S. application Ser. No. 706,204, filed July 19, 1976, now abandoned.
BACKGROUND OF THE INVENTION
This invention concerns mechanical devices for transferring mechanical power from components with reciprocating motion to components with rotary motion.
In U.S. Pat. No. 3,955,432, issued May 11, 1976, there is disclosed a transmission having a first element defining a pair of rolling surfaces of revolution about a first axis, a second element having a pair of rolling surfaces of revolution on a second axis intersecting the first axis and including a system for urging the rolling surfaces of the second element against those of the first element, which system is gyroscopic in origin. Specifically, inertial means associated with the second element are deployed to develop a gyroscopic couple which acts to retain the rolling surfaces of the second element against the rolling surfaces of the first element at two points of contact located one on each side of a plane perpendicular to the first axis at the point of intersection thereof with the second axis. The gyroscopic couple thus developed is a combined function of the moment of inertia of the second element with respect to the second axis, the angle at which the first and second axes intersect, the rotational velocities of the second element around the first axis. In this transmission, the gyroscopic couple operates to both rock the second element around the point of axes intersection and maintain both rolling surfaces of the second element against both such surfaces of the first element in rolling friction contact.
To vary the ratio of input and output speeds of the transmission disclosed in this patent, provision is made to modify the angle of inclination of the second axis with respect to the first axis. As a result, the ratio of the radii of circles described by the points of rolling surface contact between the first and second elements, respectively, will be modified. Such a transmission is particularly well suited for the transmission of large forces due to the development of normal contact pressure by the gyroscopic couple while avoiding excessive axial forces on the transmission gear shafts as well as radial forces on the bearing supporting the second element.
Also in a corresponding U.S. application for patent Ser. No. 706,291, filed July 19, 1976 and owned in common with the present invention, the basic principles underlying the transmission disclosed in the afore-mentioned U.S. patent are again used but in an arrangement having an increased range of speed ratio variation without the requirement for variation in the angle of intersection between the axes of the respective first and second elements. This characteristic of operation is achieved by providing on one of the elements a pair of oppositely convergent cone-like rolling surfaces in which the apical half-angle of surface convergence (or divergence) is approximately equal to the angle at which the axes of the two elements intersect one another. The other of the two elements is provided with ring-like tracks providing the rolling surfaces so that the speed ratio of the transmission may be variable with the ratio of the rolling surface radii on the ring-like tracks to the radii of the cone-like members at the two points of rolling contact between the two elements.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, the desirable characteristics of the variable speed friction or traction drive transmissions of these prior disclosures, particularly the latter, are advantageously deployed in a piston machine such as a reciprocating engine, to convert the power developed by synchronously reciprocating pistons to a rotary output shaft capable of operating at variable angular velocities independent of the frequency of piston reciprocation. The invention is particularly suitable for use with engines of the type which operate in accordance with the known Stirling cycle as well as those adaptable to other forms of reciprocating energy such as Otto and Diesel cycle engines and steam engines.
The transmission of piston thrust to the variable speed traction drive or transmission is effected preferably by a gimble supported bed plate capable of movement in a manner of a swashplate and operably connected to one of the two transmission elements in a manner to develop a nutational type movement in that element. Such movement is converted to a rotary output in a manner similar to the transmissions disclosed in the aforementioned said prior application.
A primary objective of the present invention, therefore, is the provision of an energy conversion machine such as an engine in which power developed in synchronously reciprocating piston is converted variable speed to a rotary power output in a manner such that output speed may be varied independently of the frequency of piston reciprocation. Other objects and further scope of applicability of the present invention will be apparent from the detailed description to follow taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-section (line a--a of FIG. 3) illustrating an engine incorporating the present invention;
FIG. 2 is a transverse cross-section on line b--b of FIG. 1;
FIG. 3 is a transverse section on line c--c of FIG. 1;
FIG. 4 is a transverse section along line d--d of FIG. 1; and
FIG. 5 is a perspective view, partially cut away to illustrate the principal components of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 of the drawings, a heat engine is shown to include an enclosure 1 of high heat-resistant material, such as ceramic, for example. The approximately circular enclosure delimits a chamber 16, closed at one end by a ceramic wall 2 and communicating with the exterior by two apertures 3 and 4 in a well 6 which closes the other end of the chamber. The center of the enclosure is in longitudinal axis of the heat engine.
The apertures 3 and 4 are designed so as to permit the entry of air needed for combustion of fuel and for evacuation of the exhaust gases in the direction indicated by the arrows 7 and 8. The fuel is supplied by tubing 9 in the longitudinal axis of the engine and injected into the chamber through the port 10. A sparkplug 11 connected to an electric source (not shown) by the wire 12 initiates combustion. Air enters the chamber by a number of ports 13 in well 14 so as to intermix air and fuel homogenously.
In order to recover a part of the heat in the exhaust gases, a rotating heat exchanger 15 is provided so that cold air is heated in passing through the exchanger 15 while the exhaust gases impart their heat to exchanger 15. Within chamber 16 are four finned reheaters of which two, 17 and 18, are visible in FIG. 1. A good heat-conducting gas with low viscosity such as hydrogen or helium circulates within the reheaters. Although the connection of the reheaters to the chambers of the heat engine will be described below, they function to facilitate the transfer of heat from the fluid in them to the combustion gases.
The heat engine has a system of enclosures mounted on the body 19 in a circle around longitudinal axis 5 of the engine. Specifically, there are four variable-volume enclosures at high mean temperature (only 20 and 21 are shown in FIG. 1) and four variable-volume enclosures at lower mean temperature (only 22 and 23 are shown in FIG. 1).
The chambers at high mean temperature are housed in the ceramic wall 2 terminating the combustion chamber 16. Tubing 24 and 25 connect chambers at high mean temperature 20 and 21 to chambers at low mean temperature 22 and 23 which are shifted by 90° around engine axis 5 in relation to the hot chamber. The tubing also connects the reheaters 17 and 18, regenerators 26 and 27 and radiators 28 and 29.
The regenerators are of ceramic material and intended to withdraw a part of the heat energy of an active fluid when it is hot and restitute it after cooling. The radiators 28 and 29 have a flow of water and cool the hot fluid which flows through them.
The active fluid (hydrogen or helium) circulates alternately from the hot chamber to the cool chamber and traverses, first in one and then the other direction. The reheater, regenerator and radiator conform with a Stirling cycle.
The enclosures are delimited by cylindrical walls 80 and 81 in which the pistons move back and forth. The latter are mounted in a circle around the longitudinal engine axis. The hot variable-volume space 20 is closed by the face 30a of piston 30; the cool variable-volume 30b of the same piston by the other face 30b. The piston cylinders are mounted integral with the body 19 and the ceramic wall 2 of the combustion chamber 16. They are distributed uniformly offset by 90° around axis 5.
The engine thus shown operates in accordance with the well-known Stirling cycle which need not be described further herein. It will be recalled that it has four phases (compression, heating, expansion, cooling) and that the pistons travel parallel to axis 5. It will be recalled also that the alternate motion of the pistons is out-of-phase by an angle of about 90°.
The alternate motion of the pistons is transmitted by a system of connecting rods 32 and 33 to a transmission mechanism described further below. The connecting rods 32, 33 are joined to a system of deformable skirts 75, 76 to the walls of the low temperature space to prevent leakage. In order to balance the pressure within the chamber, a counterpressure is provided downstream of the skirt by a pressurized fluid injected through the channel 77.
The mechanism shown on the right side of FIG. 1 has a rotating component 34 of biconical form and rotates integrally with the take-off or power shaft 35. It is supported by two bearings 36, 37 centered on the axis 5 so that the component 34 has two conical rolling tracks 34a, 34b, arranged symmetrically on either side of the point S of axis 5. These revolve around this axis and their transverse decreases progressively starting from the perpendicular plane of the point S of axis 5.
The mechanism also has a mobile bed plate 38 which is prolonged by a nearly cylindrical body 39 in which are mounted two rolling tracks 40, 41 movable axially. The axis 120 of the cylindrical body passes through the point S of axis 5 and is inclined from the latter by an angle a. The angle a is nearly equal to the half-angle at the apex of the conical rolling tracks. The rolling tracks 40, 41 revolve around axis 120 and are movable axially in relation to each other along that axis. The rolling tracks 40, 41 are formed on two annular rings and permanently disposed symmetrically in relation to the perpendicular plane of S to axis 120 of the cylindrical body. They are operated by two threaded rods 43, 44 and each has a right-hand nut and a left-hand nut. The nuts are activated by a double hydraulic device 45 mounted at the end of the cylindrical body 39. The hydraulic fluid supply tubes of the device are shown at 46. The rolling tracks 40, 41 are kept in contact with the conical tracks 34a, 34b of the rotating component at the two points P1 and P2 by mechanisms to be described below.
The bed plate 38 is supported by the body by a system of cardans shown in FIG. 2. The cardans support the bed plate on the body so that the plate can veer or swash around the point S. The axis 120 therefore describes a cone of apex S and of half-angle a around axis 5 and the rotating component is centered at the point S.
At the periphery of the bed plate are provided four bosses 47, 48 shown in FIG. 1. They are designed to receive ball-and-socket joints 49-50 whose centers lie in the plane perpendicular to the axis 120 at S, and are integral with links 51, 52. These links are also integral with the other end of ball-and-socket joints 53, 54 and these joints themselves are lodged in the semicircular recesses 55, 56 at the ends of the connecting rods 32, 33. Lubricating circuits 57 keep the bearings of the rotating component oiled, together with the ball-and-socket joints and the cardan articulations.
The linkages described between the pistons and the bed plate induce the latter in a swashing movement with angle a and speed α around the point S.
The mechanical system for forcing the rolling tracks 40, 41 of the bed plate against the rolling tracks 34a, 34b of the rotating element is of gyroscopic origin and described in the aforementioned issued patent. A complete description of the system is believed unnecessary herein except to note that the whole of the forces of elementary inertia originating in the mass of the bed plate and the cylindrical body prolonging it, reduces itself, due to the fact that the center of gravity of the bed plate lies on the point S, to a couple whose intensity is a function of:
(a) the principal moments of inertia of the bed plate and of the cylindrical body in relation to the axis 120 and in relation to an axis passing through S perpendicular to this axis;
(b) of the angle a of inclination of the axis 120 in relation to longitudinal axis 5;
(c) of the speed α of axis 120 in relation to axis 5;
(d) of the speed β* of the bed plate and of the body around the axis 120 (the speed β* having been measured in a frame of reference rotating at the speed α with axis 120); the speed β* of the bed plate and body around axis 120 is zero in an absolute frame of reference linked to the body; consequently, the absolute value β* is equal to the speed α of axis 120 around axis 5.
This couple causes the tilt of bed plate and cylindrical body so as to force the tracks 40, 41 in contact at P1 and P2, with the rolling tracks of the rotating component. The pressure of contact at P1 and P2 produced by the gyroscopic couple is adequate in normal operation to prevent slippage of tracks 40 and 41 on the tracks 34a and 34b.
It will be noted that the own inertial forces of the alternate motion of the pistons are added to those of the gyroscopic couple. These inertial forces reach their maximum at the end of their stroke and appreciably contribute to force the tracks of the rotating component.
The bed plate entrained into a swashing motion around the point S by the pistons entrains in its turn, by the intermediary of the tracks in rolling friction contact, the rotation of the rotating component and, consequently, the rotation of take-off shaft 35.
In the preceding U.S. Pat. No. 3,955,432, there was described the kinematic relation linking the speed of rotation ω of the rotating component to the speed α of the axis 120 around axis 5. This relation is a function of the ratio of the gyratory radii of the points P1 and P2 in relation to axis 5 and in relation to axis 120. A modification of this ratio involves a modification of the ratio of speeds α and ω of the bed plate and of the rotating component. Since the speed α of the bed plate itself is a function of the frequency of the alternate motion of the pistons, it is possible to vary the speed ω of the take-off shaft without modifying the frequency of piston action by changing the valve of the ratio of the gyratory radii. We have previously described the mechanism permitting axial displacement of tracks 40, 41. Taking into account the angular equality between the half-angle at the summit of the rolling tracks 34a and 34b and the angle of inclination a of the axis 120 from axis 5, it will be seen that the axial displacement of tracks 40 and 41 does not produce any changes in the angle of inclination a or any change of the gyratory radius of the point of contact around axis 120. On the other hand, this axial displacement modifies the value of the gyratory radius of the contact points P1 and P2 in relation to axis 5. Due to this fact, the mechanism of axial displacement of the pistons allows change in the speed ω of the take-off shaft in relation to the frequency of piston action.
The ends of the cylindrical body 39 of the mobile end plate are linked for rotation, by ball-and-socket joints like 91, with two auxiliary components 90, 92. The latter are themselves mobile in rotation in relation to the body around axis 5. They rotate around this axis at the same speed α as axis 120. The masses of the two components 90, 92 are so distributed as to balance out the rotating couple of reaction on the body which is caused by the mechanical system forcing the tracks of the bed plate against the tracks of the rotating component. In addition, one of the auxiliary components 92 has a toothed rim meshing with both a crown wheel 93 of take-off shaft 94 and with crown wheel 95 activated by a starting mechanism 96. The latter is provided to initiate the veering motion of the bed plate during the starting of the transmission and the heat engine. The take-off shaft 94 is used to activate the mechanisms of the heat engine which must be set in motion at a speed proportional or equal to the speed α of axis 120 around axis 5.
In FIG. 2 of the drawings, is a transverse cross-section along b--b of FIG. 1, certain components will be recognized from FIG. 1. The system of cardans supporting the veering or swashing bed plate is shown clearly to include a square cage 58 which turns freely on pivots 59 and 60 integral with the body and their axis passes through the point S. This cage itself has two pivots 62, 63 whose axes also pass through the point S and move freely in the two bosses 64, 65 of the bed plate 38.
A network of lubricating circuits is also shown in FIG. 2 in which oil is passed to the bearings of the pivoting parts, specifically the four lodgings 47 seen from the back, in which are articulated the ball-and-socket joints of the connecting-rod head and the four pivots 59, 60, 62, 63 for articulation of cage 58.
Also in this figure, the ends of the threaded rods 43, 44 which activate the rolling tracks like 41 along the longitudinal direction to axis 120 are shown. It will be noted that the rolling tracks like 41 have shoulders such as 41a sliding within grooves such as 66 in the cylindrical body integral with the bed plate. Due to the grooves and shoulders, the rolling tracks mobile axially are integral in rotation with the veering motion of the bed plate.
FIG. 3 represents a transverse cross section along c--c of the bed plate in FIG. 1 and specifically the cylindrical body prolonging the bed plate. The threaded rods 43, 44 are shown for activating the annular ring on which are formed the tracks like 41. It shows also the four cutouts 67, 68, 69, 70 which allow passage of articulated links along cylindrical body 39.
FIG. 4 represents a transverse cross section along d--d of the cylindrical body of the bed plate on which the hydraulic device is mounted. The threaded rods 43, 44 are caused to rotate by the gears 72, 73 lodged in recesses of the cylindrical body. These gears mesh with crown wheel 74 rotating freely in a groove of the cylindrical body whose axis is axis 120 of the cylindrical body.
In a known manner, the hydraulic fluid activates the displacement of the crown wheel thus rotating the threaded rods back and forth and consequently inducing the axial displacement of the rolling tracks 40, 41.
This invention has been illustrated by a single example of design of a thermal cycle and of a mechanism of transmission by friction. However, it is evident that, conforming with the invention, different thermal cycles may be employed.
The invention now having been explained and its advantages set forth by a detailed example, the petitioner for a patent thereon reserves his exclusive rights for the entire duration of the patent limited only to the terms of the following claims. | A power transmitting mechanism for converting the thrust of reciprocating pistons to a rotary output shaft at speeds independent of the frequency of piston reciprocation. Power developed by expanding gases in accordance with well-known thermal cycles, such as the Stirling cycle, is transmitted by pistons to a bed plate capable of swashing motion about a point on the axis of the output shaft. The shaft is provided with a pair of oppositely convergent or biconical friction surfaces engageable by annular tracks carried with the bed plate in orbit which may be characterized as nutational. Axial adjustment of the annular tracks toward and away from the point on the output shaft varies the output shaft speed independently of input speed or piston frequency. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 62/040,182, filed Aug. 21, 2014. This application is a continuation-in-part of U.S. application Ser. No. 14/292,881, filed May 31, 2014, which claims priority to U.S. Provisional Application No. 61/830,257, filed Jun. 3, 2013. Each of the above patent applications is incorporated herein by reference in its entirety to provide continuity of disclosure.
TECHNICAL FIELD
[0002] The present invention relates generally to a corner bead for cementitious fireproofing of structural steel members and, more particularly, to a device that is self-aligning in installation and allows the accurate gauging of the thickness of the fireproofing material along three surfaces.
BACKGROUND OF THE INVENTION
[0003] In the art of a corner bead for fireproofing structural steel, prior approaches conventionally include a v-bend corner bead having adjustable legs (flanges). This type of corner bead is mostly used in the plastering and stucco trades. The previously utilized corner bead is constructed of wires welded into a lattice that is v-shaped in section as shown in FIG. 1 .
[0004] In installation, the longitudinal base wires of the v-shaped corner bead are attached with a tie wire either onto a metal lath or onto a wire mesh, and further attached to the steel member to be fireproofed as shown in FIG. 2 . At best, this allows for distribution of the fireproofing material along two surfaces after a complex negotiation of the correct height of the two flanges; to wit, to establish the correct fireproofing thickness, one must establish the correct height of the vertex by shrinking or expanding the distance between the legs (flanges) of the corner bead defined by the vertex. Using this technique, the alignment of the corner bead with the adjacent surface is difficult and great skill is required to install the corner bead for fireproofing structural steel.
[0005] The prior art includes many problems, including the difficulty of properly adjusting the traditional corner bead to the adjacent surface, the uneven application of fireproofing material, and the lack of a dam for the wet cement material. Despite these well-known and long-existing problems, and a readily apparent market for a solution, the prior art does not disclose or suggest a viable, cost-effective solution to the aforementioned problems of the prior art.
[0006] Accordingly, a need exists for an improved corner bead to avoid inaccuracy in gauging the thickness of the fireproofing material and to allow easy installation along three surfaces. An improved self-aligning double wire corner bead is inexpensive to manufacture and easy to install.
SUMMARY
[0007] The present invention provides a self-aligning, double wire corner bead that allows to make, in an accurate and quick manner, corners of a fireproofing material around structural steel members, said fireproofing material having uniform thickness around the structural steel member. This is accomplished by bending a single strip of welded wire fabric of pre-determined width along a plurality of longitudinally extending lines (axes) to provide a profile of a metal sheet having a plurality of dihedral angles, two wings of the desired width, a single wire membrane and a double wire membrane, said double wire membrane comprising a first leg and a second leg as substantially shown in FIGS. 4 and 5 .
[0008] The angle at which each wing meets the single wire membrane and a second leg of the double wire membrane of the device, respectively, determines the thickness of the fireproofing material distributed around the structural steel member along three surfaces. Further, said thickness may be modified by changing the width of each respective wing. The uniformity in thickness of the fireproofing material distributed around three surfaces of the structural steel member is achieved by bending the first wing and the second wing at approximately the same angle in relation to the single wire membrane and the second leg of the double wire membrane, respectively. The uniformity in thickness of the fireproofing material distributed around all surfaces of the structural steel member in a contour type application is achieved by using the same width of the single metal strip bent to create an identical single metal sheet profile for all corners of the structural steel member.
[0009] It is further an object of the present invention to provide an improved corner bead for fireproofing structural steel without the need of adjusting the legs.
[0010] Another object of the present invention is to provide novel means of installing the corner bead by easier attachment to the structural steel.
[0011] Another object of the present invention is to provide an improved technique for application of accurate thickness of fireproofing material along three surfaces under any construction condition for making said fireproofing of structural steel members.
[0012] A further object of the present invention is to provide a dam to form a roughened surface on the first application of fireproofing material until it hardens along three surfaces.
[0013] While satisfying these and other related objectives, the present invention provides an improved, self-aligning, double wire corner bead for fireproofing structural steel which is very competitive from a mere economic standpoint. The corner bead of the present invention consists of a single strip of welded wire fabric cut to a desired width for the fireproofing thickness and bent along a plurality of longitudinal axes to form a set of wings, a single wire membrane, and a double wire membrane, said double wire membrane having a first leg and a second leg, said first leg seamlessly becoming said second leg through a process of bending of said double wire membrane such that said first leg is substantially parallel to said second leg, and wherein said single wire membrane and said double wire membrane are attached by the attachment means to the lath distributed around the structural steel member.
[0014] In accordance with the present invention, the corner bead includes a single elongated strip of welded wire fabric of pre-determined width, said single strip of welded wire fabric comprising a set of flexible mesh strips as shown in FIG. 3 .
[0015] According to one embodiment of the present invention, the improved double wire corner bead allows each element of the bent wire mesh of the corner bead to perform different functions that are essential for the successful completion of the fireproofing process along three surfaces.
[0016] The single wire membrane and the double wire membrane provide a flat portion of a grid (mesh) through which pneumatic or screw type fasteners attach the mesh to the structural steel at the appropriate location. In addition, the double-wire membrane provides additional support for two wings positioned at the opposite corners of the steel structure member, hence facilitating one piece of wire mesh to cover two corners and three surfaces of the structure. This easy application establishes automatic alignment of the corner bead along three surfaces, eliminates the cumbersome process of shrinking or expanding the distance between the legs of the traditional bead, as well as provides only one strip of metal of the desired width to allow fireproofing of two corners of the steel structure member along three surfaces at the same time in a contour-method application of the fireproofing material.
[0017] The width of the set of wings and/or the angle at which the first and the second wing meet the single wire membrane and the second leg of the double wire membrane, respectively, determines the thickness of the fireproofing material distributed along three surfaces by providing a rigid screed edge along a nose. Therefore, the correct amount of fireproofing material is distributed adjacent to the corner bead creating a leveled application throughout the surface.
[0018] The width of the set of wings also provides a dam to form a roughened surface on the first application of the fireproofing material until the fireproofing material hardens. This forming action allows successive application of the cement material to the adjacent surface.
[0019] In another aspect, the present invention includes a method of manufacturing an improved self-aligning, double wire corner bead for fireproofing structural steel comprising a single strip of welded wire fabric cut to the desired width for the fireproofing thickness and bent along a plurality of longitudinally extending lines (axes) to form a profile of a metal sheet, a first longitudinal line to define a first wing and a single wire membrane extending laterally therefrom at a first angle of approximately greater than 90 degrees but less than approximately 180 degrees relative to each other and wherein said single wire membrane is secured to a structural steel member and said first wing is configured to establish a desired thickness of the fireproofing material along two surfaces by providing a rigid screed edge along the nose, a second longitudinal line to define said single wire membrane and a first leg of a double wire membrane extending from said single wire membrane in a continuous manner and at a second angle of approximately 90 degrees relative to each other, a third longitudinal line to define said first leg of said double wire membrane and a second leg of said double wire membrane such that said first leg is positioned substantially parallel to said second leg (the second leg substantially overlaps the first leg), and wherein said double wire membrane is secured to said structural steel member, and a fourth longitudinal line to define a second wing and said second leg of said double wire membrane, said second leg extending downwardly from said second wing at a third angle of approximately greater than 90 degrees but less than approximately 180 degrees relative to each other, and wherein said third angle is substantially equal to said first angle.
[0020] In a further aspect, the present invention includes a method of finishing a set of corners for cementitious fireproofing in a contour application of a set of structural steel members, the method comprising the steps of: selecting a corner bead comprising a single strip of welded wire fabric cut to the appropriate width for the fireproofing thickness and bent along a plurality of longitudinally extending lines, to provide a profile having a plurality of dihedral angles, wherein a first longitudinal line to define a first wing and a single wire membrane extending laterally therefrom at a first angle of approximately greater than 90 degrees but less than approximately 180 degrees relative to each other and wherein, said single wire membrane is secured to a structural steel member and a first wing is configured to establish a desired thickness of the fireproofing material along two surfaces by providing a rigid screed edge along the nose, a second longitudinal line to define said single wire membrane and a first leg of a double wire membrane extending from said single wire membrane in a continuous manner and at a second angle of approximately 90 degrees relative to each other, a third longitudinal line to define said first leg of said double wire membrane and a second leg of said double wire membrane such that said second leg is extending from said first leg of said double wire membrane in a continuous manner in such a way that said first leg is positioned substantially parallel to the second leg (the second leg substantially overlaps the first leg), and wherein said double wire membrane is secured to said structural steel member, and a fourth longitudinal line to define a second wing and said second leg of said double wire membrane, said second leg extending downwardly from said second wing at a third angle of approximately greater than 90 degrees but less than approximately 180 degrees relative to each other, and wherein said third angle is substantially equal to said first angle.
[0021] A dihedral angle (also called a face angle) is the internal angle at which two adjacent faces of each section member of the double wire corner bead is delimited by the two inner faces, e.g., angle α 1 formed between adjacent faces of the first wing and the single wire membrane, angle α 2 formed between adjacent faces of the second wing and the second leg of the double wire membrane and angle β formed between adjacent faces of the single wire membrane and the first leg of the double wire membrane. The fourth angle created along the third longitudinal line between the first and the second leg of the double wire membrane is substantially zero (0) degrees so that the first leg and the second leg substantially overlap each other, and are approximately parallel, with respect to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view of a small section of a corner bead according to the prior art.
[0023] FIG. 2 is a cross-sectional schematic view of a fireproofing structure utilizing a prior art corner bead installed according to a contour method.
[0024] FIG. 3 is a perspective view of an exemplary small section of the corner bead of the present invention bent along a longitudinal axis and manufactured according to an embodiment of the present invention.
[0025] FIG. 4 is an enlarged cross-sectional schematic view of the self-aligning, double wire corner bead of the present invention.
[0026] FIG. 5 is a cross-sectional schematic view of a fireproofing structure utilizing a self-aligning, double wire corner bead of the present invention according to the contour method.
DETAILED DESCRIPTION
[0027] Referring to FIG. 3 , corner bead 10 includes a plurality of longitudinal ribs 16 arranged substantially parallel with respect to a plurality of longitudinal axes, including longitudinal axis A and to each other, and a plurality of transverse ribs 18 distributed between and extending substantially perpendicular to the plurality of longitudinal axes and the plurality of longitudinal ribs 16 . A set of void areas 20 is defined by the plurality of longitudinal ribs 16 and the plurality of transverse ribs 18 , such that each void area 20 is bounded by at least two longitudinal ribs 16 and at least two transverse ribs 18 . A section of corner bead 10 includes a single strip of welded wire fabric cut to a predetermined length L and a predetermined width W. The predetermined length L and the predetermined width W correspond to a predetermined fireproofing thickness.
[0028] In a preferred embodiment, corner bead 10 is made of a suitable metal, such as 16 gauge wire. Other suitable materials known in the art may be employed, including suitable plastics. In a preferred embodiment, corner bead 10 is a double welded wire fabric.
[0029] In a preferred embodiment, corner bead 10 has a set of bends integrally formed in corner bead 10 along the plurality of longitudinal axes. Any number of bends may be employed. Longitudinal axis A defines first wing 12 and single wire membrane 11 . First wing 12 and single wire membrane 11 form angle α 1 of approximately greater than 90 degrees, but less than approximately 180 degrees as further illustrated in FIGS. 4 and 5 . A set of edges of first wing 12 defines a substrate to which nose 14 is attached. Nose 14 , first wing 12 , and second wing 12 ′ (shown in FIG. 5 ) provide a rigid edge having a dam-like function, as will be further described below.
[0030] In a preferred embodiment, nose 14 is made of a suitable plastic, such as polyvinyl chloride. Other suitable materials known in the art may be employed.
[0031] Referring to FIG. 4 , corner bead 10 is bent along a plurality of longitudinal lines 41 , 42 , 43 , and 44 , to provide a substantially continuous profile having a plurality of dihedral angles. Longitudinal line 44 defines first wing 12 and single wire membrane 11 extending laterally therefrom at angle α 1 . Angle α 1 is approximately greater than 90 degrees, but less than approximately 180 degrees. Each of noses 14 is attached to first wing 12 and second wing 12 ′. Longitudinal line 42 defines single wire membrane 11 and leg 31 of double wire membrane 30 extending from single wire membrane 11 in a continuous manner. Single wire membrane 11 and leg 31 are separated by angle β. Angle β is approximately 90 degrees. Longitudinal line 43 defines leg 31 of double wire membrane 30 and leg 31 ′ of double wire membrane 30 . Leg 31 ′ is positioned substantially parallel to leg 31 . Leg 31 ′ substantially overlaps leg 31 . Longitudinal line 41 defines second wing 12 ′ and leg 31 ′ of double wire membrane 30 . Leg 31 ′ extends away from second wing 12 ′ at angle α 2 . Angle α 2 is approximately greater than 90 degrees, but less than approximately 180 degrees.
[0032] In use, the improved, self-aligning, double wire corner bead 10 of the present disclosure is utilized in a contour-like manner, surrounding a structural steel member with fireproofing material. Referring to FIG. 5 , single wire membrane 11 is secured to structural steel member 24 . First wing 12 is configured to establish a desired thickness of fireproofing material 22 along two surfaces of the structural steel member by providing a rigid screed edge to which nose 14 is attached. Double wire membrane 30 is secured to structural steel member 24 , as will be further described below. Fireproofing material 22 surrounds the dimensions of the structural steel member 24 in a contour-like manner, tracing structural steel member 24 in all dimensions. The single strip of corner bead 10 allows uniform distribution of fireproofing material 22 along three surfaces, surfaces S 1 , S 2 , and S 3 .
[0033] Referring to FIGS. 4 and 5 , the width of the wings 12 and 12 ′ determines distances D 1 , D 2 , and D 3 , and defines generally planar surfaces S 1 , S 2 , and S 3 forming a set of corners of fireproofing material 22 distributed around structural steel member 24 . Similarly, any of distances D 1 , D 2 , and D 3 are optionally altered by changing angles α 1 and α 2 . Angles α 1 and α 2 are substantially equal and measure approximately greater than 90 degrees, but less than 180 degrees. Angle β measures approximately 90 degrees. For example, the smaller (less obtuse) angle α 1 is between first wing 12 and the single wire membrane 11 the longer distance D 1 is between lath 26 and surface S 1 , and the shorter distance D 3 is between lath 26 and surface S 2 . Similarly, the less obtuse angle α 2 is between second wing 12 ′ and leg 31 ′ of double wire membrane 30 , the longer distance D 2 is and the shorter distance D 1 is making distributed fireproofing material 22 thicker along surface S 3 in relation to a thinner strip of fireproofing material 22 along surface S 1 .
[0034] In a preferred embodiment, the determination of angles α 1 and α 2 should be such that a uniform thickness of fireproofing material 22 along surface S 1 is achieved.
[0035] In one embodiment, lath 26 is distributed around structural steel member 24 . Single wire membrane 11 is attached through lath 26 into structural steel member 24 by pneumatic fastener 28 at a single fastening position on single wire membrane 11 . Other joining or attaching means known in the art, such as welded pins or screws, may be employed.
[0036] In another embodiment, each of single wire membrane 11 and double wire membrane 30 is attached to structural steel member 24 by pneumatic fastener 28 at a single fastening position on double wire membrane 30 .
[0037] In another embodiment, leg 31 and leg 31 ′ of double wire membrane 30 are attached through lath 26 into structural steel member 24 by pneumatic fastener 28 at a single fastening position on double wire membrane 30 . Other joining or attaching means known in the art, such as welded pins or screws, may be employed. According to one embodiment of the present invention, lath 26 is optionally distributed along the entire perimeter of structural steel member 24 to be fireproofed (not shown). In another embodiment, lath 26 is distributed along a portion of the perimeter of structural steel member 24 .
[0038] In other embodiments, any number of fastening positions and locations may be employed.
[0039] The width of first wing 12 and second wing 12 ′ along with nose 14 attached to the outer edges of both wings serves as a dam during the process of fireproofing. Fireproofing material 22 is then sprayed onto lath 26 and screened off using the location of nose 14 to determine the finished thickness of fireproofing material 22 .
[0040] Referring to FIG. 5 , in a shop application, i.e., fireproofing material 22 is applied to structural steel member 24 in a pre-fabrication facility, the cementitious composition is sprayed or poured one layer at a time on a surface of lath 26 positioned horizontally. Structural steel member 24 is then rotated 90 degrees and the adjacent surfaces are positioned horizontally to allow easy application of fireproofing material 22 . With this process in place, each successive spraying is performed which allows hardening of fireproofing material 22 before the next rotation of structural steel member 24 . As can be seen, the dam-like functionality of corner bead 10 according to one embodiment of the present invention is critical as it provides an appropriate keying surface to bond the subsequent layers of fireproofing material 22 . Each structural steel member 24 is turned to uniformly apply the cementitious material to all surfaces.
[0041] It will be appreciated by those skilled in the art that any type of member may be employed.
[0042] In a field application on a job site, structural steel members 24 are erected into a structure prior to fireproofing, and all surfaces of structural steel member 24 may be sprayed or troweled onto the surface of lath 26 at the same time (not shown).
[0043] It will be appreciated that the invention is not restricted to the particular embodiment that has been described, and that variations may be made therein without departing from the scope of the invention as defined in the appended claims, as interpreted in accordance with principles of prevailing law, including the doctrine of equivalents or any other principle that enlarges the enforceable scope of a claim beyond its literal scope. Unless the context indicates otherwise, a reference in a claim to the number of instances of an element, be it a reference to one instance or greater than one instance, requires at least the stated number of instances of the element, but is not intended to exclude from the scope of the claim a structure or method having more instances of that element than stated. The word “comprise” or a derivative thereof, when used in a claim, is used in a nonexclusive sense that is not intended to exclude the presence of other elements or steps in acclaimed structure or method. | A self-aligning, double wire corner bead for fireproofing structural steel along a plurality of surfaces, the corner bead having a single strip of welded wire fabric cut to a predetermined width for the fireproofing thickness and bent along a plurality of longitudinally extending lines, to provide a profile having a plurality of dihedral angles is disclosed. A nose is installed along two edges. A method of finishing the corners for fireproofing of structural steel member using an improved corner bead includes the step of attaching the corner bead through a lath to the structural steel member utilizing fasteners. The mesh of the corner bead provides a dam to form a roughened surface on the first application of fireproofing material until it hardens. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. provisional applications 60/741,686 and 60/741,687, both filed Dec. 2, 2005, which are incorporated by reference along with any other references cited in this application.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the field of electronic design automation and, in particular, to improved techniques for performing optical proximity correction.
[0003] The manufacture of integrated circuits strives to place ever smaller features onto a given area of the integrated circuit chip. One challenge encountered in this effort to fabricate smaller features is the diffraction of the light used in photolithography. That is, the quality and fidelity of the microlithography stage of very large scale integrated (VLSI) circuit chip production depends on the wavelength of the light source and the size of the features to be printed.
[0004] Recent sub-wavelength lithography approaches aim to use wavelengths that are larger than the minimum feature size to generate the images, (e.g., light with a wavelength of 193 nanometers is being used to generate features with dimensions of 90, 65, or 45 nanometers). This approach, however, requires methods for the correction of degradations and distortions in the final pattern caused by light diffraction. That is, the photolithography mask used to generate the desired circuit pattern includes structures that anticipate and, at least partially correct for, the imperfections arising from striving to fabricate small features.
[0005] A computational simulation of the exposure and lithographic is run and the degradations or distortions are computed with various additions, inclusions and adjustments to the mask design. A mask design is selected that improves the final structure. These methods, commonly known as optical proximity correction (OPC), are mainly dependent on the optical system and mask features and may be computationally intensive. While regions having densely packed features tend to be more prone to distortions (the “proximity” effect), OPC calculations are not limited to such regions and can be advantageously applied to less-dense regions of the circuit.
[0006] OPC typically numerous features in a pattern layout to be computationally processed one or more times. Recent advances in semiconductor manufacturing allow billions of transistors (i.e., multibillion features) to be placed on a single chip. The well-known “Moore's law” postulates that the number of transistors that can be placed on a single chip doubles about every 12-24 months. Unfortunately, despite the advances in the central processing unit (CPU) clock speed and computing power, the gap between the computational power required for OPC calculations and the available CPU processing power keeps increasing. That is, the computing power required to efficiently execute the OPC calculations in a timely manner is growing at a faster rate than the available CPU power in a reasonably priced engineering workstation.
[0007] To further complicate the issue, the number of masks or layers to which OPC should be applied increases at each new semiconductor device manufacturing node. Since the features are getting smaller with every manufacturing node while the illumination wavelengths remain the same or decrease at a slower rate, the number of neighboring features effecting the fidelity of each feature increases. Therefore, the computational processing power required to perform OPC operations on new chip designs has been increasing at a rate of approximately factors of three or four or more for each successive manufacturing node.
[0008] Presently, the generation of optically corrected masks takes from many hours to several days per mask and the complexity of this process continues to grow. Because the features printed after the OPC process may still be different from the desired features, the impact of each feature on the functionality and performance of the chip needs to be readdressed in an iterative manner. A typical VLSI design process consists of several iterations of mask generation, OPC process, and interpretation of the results. These iterations may contribute several months of delay in the chip qualification and manufacturing process.
[0009] The persistent time-to-market pressures on new chip designs mandate improved methods to estimate and shorten the impact of the OPC process in the early stages of the design. Since it is computationally prohibitive to perform many iterations of OPC on a full-chip scale, partial or simple model-based OPC approaches are being applied in limited fashion, still necessitating full-chip OPC once the design is completed.
[0010] Therefore, a need exists in the art for improved systems and methods that shorten the time required to perform OPC, improve the accuracy of OPC methods, and are scalable to address larger chip designs.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention relates generally to the field of manufacturing integrated circuits and, more particularly, to using optical proximity correction (OPC) to improve the masks used for the printing of microelectronic circuit designs. Specifically, the present invention relates to the execution of OPC techniques on hardware or software platforms, or a combination of these, utilizing specialized processing units.
[0012] Accordingly and advantageously the present invention relates to systems and methods for the execution of OPC algorithms on hardware or software platforms, or combination, with specialized processing units.
[0013] In some embodiments of the present invention, spatial domain OPC computations are executed on a hardware or software system, or combination, comprising one or more specialized processing units. Examples of the specialized processing units include central processing units (CPUs), graphical processing units (GPUs), physics processors, cell processors, digital signal processors (DSPs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and the like. Portions of the OPC computational task may be transformed into the form of mathematical manipulations on matrices and vectors. GPUs may be particularly well suited to performing such operations on matrix and vector data.
[0014] The GPU or GPUs may operate on the data until the result converges on the target model within a predetermined error limit. The operations may include changing the shapes of mask features and may include a detailed model of the illumination and optics systems used for exposing the pattern in the photoresist layer. The final data may be transformed back to the original data format and exported for generation of the mask used to print the pattern on the semiconductor device. GPUs will be used as an example of a specialized processor, but this is not intended to limit the scope of the teaching of the present invention to GPUs. The present invention may utilize any of the specialized processors mentioned previously, and other substantially similar processors as understood by those having ordinary skills in the art and as similar or related processors may be developed later.
[0015] In an embodiment, the invention is includes: a computing system having at least one central processing unit and at least one graphics processing unit; a user interface for interacting with the computer system; a computer readable medium including data describing the size and placement of features to be formed on a photolithography exposure mask used to manufacture semiconductor devices; a computer readable medium including optical proximity correction calculation procedures for acting upon the data, where at least a portion of the optical proximity correction calculation procedures are executed using the graphics processing unit; and output devices for displaying the results of applying the optical proximity correction calculation procedures executed using the graphics processing unit upon the data.
[0016] In an embodiment, the invention is a method including: providing a system having at least one central processing unit and at least one graphics processing unit; separating an optical proximity correction process into tasks depending on a type of computation required; allocating the tasks of the optical proximity correction process to the central processing unit or the graphics processing unit; and delivering output of the central processing unit and the graphics processing unit as a result of the optical proximity corrections process.
[0017] In an embodiment, the invention is includes: a computing system including a number of nodes, where each node includes at least one of at least one central processing unit or at least one graphics processing unit; an interface to couple the nodes together; a user interface for interacting with the computer system; a computer readable medium including data describing the size and placement of features to be formed on a photolithography exposure mask used to manufacture semiconductor devices; and a computer readable medium including optical proximity correction calculation procedures for acting upon the data, where at least a portion of the optical proximity correction calculation procedures are executed using the graphics processing unit in one of the nodes.
[0018] The interface may be at least on of a PCI Express bus, AGP bus, front side bus, Ethernet, the Internet, or other interface that facilitates the transfer of data in any form including serial or parallel. The computer readable medium having data describing the size and placement of features to be formed on a photolithography exposure mask used to manufacture semiconductor devices may be directly connected to one of the nodes and a portion of the data are passed through the interface to at least one other node. The direct connection may be by way of a different interface than how the nodes are connected. For example, the direct connection may be by an IDE, SATA, or USB interface.
[0019] The computer readable medium having optical proximity correction calculation procedures for acting upon the data is directly connected to one of the plurality of nodes, and at least a portion of the optical proximity correction calculation procedures are executed using the graphics processing unit on a different node from which the optical proximity correction calculation procedures are directly connected. The computer readable medium having optical proximity correction calculation procedures for acting upon the data is directly connected to one of the nodes, and at least a portion of the optical proximity correction calculation procedures are executed using the graphics processing unit of the node to which the optical proximity correction calculation procedures are directly connected.
[0020] The system may include a computer readable medium having optical proximity correction calculation procedures to split given layout information into two-dimensional subregions, where these subregion overlap with each other. There may be a computer readable medium having optical proximity correction calculation procedures to transfer the given layout information split-up into two-dimensional subregions to two or more nodes of the system. A computer readable medium having optical proximity correction calculation procedures executing on the two or more nodes may operate on the given layout information split-up into two- dimensional subregions.
[0021] A computer readable medium having optical proximity correction calculation procedures to combine results from a first node and a second node on the given layout information split-up into two-dimensional subregions. The optical proximity correction calculation procedures may combine results by stitching together the results by removing the overlapping regions.
[0022] Other objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description and the accompanying drawings, in which like reference designations represent like features throughout the figures.
Brief Description of the Drawings
[0023] FIG. 1A is a schematic representation of a typical pattern printed on a typical mask.
[0024] FIG. 1B shows the resulting pattern developed in the photoresist without OPC.
[0025] FIG. 2A is a schematic representation of a typical OPC-corrected pattern printed on a typical mask.
[0026] FIG. 2B shows the resulting pattern developed in the photoresist.
[0027] FIG. 3 is a schematic representation of a typical implementation for some OPC procedures on a typical commercial GPU.
[0028] FIG. 4 depicts an illustrative computer system pertaining to various embodiments of the present invention.
[0029] FIG. 5 shows partitioning of layout data and where each partition has overlapping regions from adjacent partitions.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The invention can be readily utilized in the improvement of OPC methods used in the manufacture of semiconductor devices.
[0031] Structures arising in the manufacture of microelectronic devices are typically formed by creating a pattern of the desired structure in a layer of photoresist deposited over the material in which the desired structure is to be formed. The pattern in the photoresist is created by exposing the photoresist to light through a patterned exposure mask. The exposed photoresist serves as a physical mask during subsequent etch step or steps where the pattern in the photoresist is transferred to the underlying material.
[0032] Distortions and degradations in the final structure arise from a combination of factors including light source variations, optical proximity effects, development process nonuniformities, and etch process nonuniformities, among others. The total amount of energy deposited in a given volume of photoresist during the exposure or printing step will determine if that volume remains or is removed during the subsequent development process. The image features being printed on current microelectronic devices may be much smaller than the wavelengths of light being used to print the features, (e.g., light with a wavelength of 193 nanometers is being used to generate features with dimensions of 90, 65, or 45 nanometers and below). The distortions may cause errors such as line thinning, end shortening, line thickening, clipping, and the like.
[0033] FIGS. 1A and 1B illustrate a typical example where the feature on the exposure mask is formed with the same size and shape as the desired structure on the chip ( FIG. 1A ). Due to the distortions described previously, the resulting pattern may not faithfully reproduce the pattern in the exposure mask as illustrated in FIG. 1 B . The distortions in this particular example have caused the final pattern to be shorter, thinner, and poorly controlled.
[0034] Various methods of OPC may be used to improve the fidelity of the final pattern transferred to the target material. The pattern that is formed on the exposure mask may be altered to compensate for various systematic distortions. One such method involves the use of serifs to augment the pattern in areas where the distortions cause feature shortening, thinning, and the like. A serif is understood to be a small feature that may be placed at a corner or vertex of a main feature. The serif may be “positive” in that it adds area to the main feature or it may be “negative” in that it subtracts area from the main feature.
[0035] FIGS. 2A and 2B illustrate a typical example of the use of both positive and negative serifs ( FIG. 2A ) on the exposure mask to alter the feature. FIG. 2B illustrates the resulting structure realized on the chip as a result of the successful use of this OPC technique. The goal of the OPC process is to calculate, improve, and ideally to optimize every feature on the exposure mask so that the resulting structure realized on the chip meets the design and performance requirements of the circuit. Clearly, when the chip has billions of transistors, each with many fine structures, the computational requirements for OPC can be very large.
[0036] Popular OPC methods in current use include two main classes, frequency domain OPC computations and spatial domain OPC calculations.
[0037] The frequency domain (FD) OPC computations use Fourier transform techniques to calculate the deformation of the features on the exposure mask to realize the desired structure on the chip. There are typically several steps to this method:
[0038] FD-1. The layout is pixilated (e.g., digitized as a pattern of pixels) and transformed into the 2-dimensional frequency domain.
[0039] FD-2. The low-pass filtering effects of the process, such as the lens system, etching characteristics, and so forth, are introduced.
[0040] FD-3. An inverse filtering process is applied to compensate for the low-pass filtering effects introduced in the previous step.
[0041] FD-4. A 2- dimensional inverse filtering is applied to transform the results of these calculations back from the frequency domain into the spatial domain.
[0042] The accuracy of the frequency domain OPC calculations increases as the number of points used increases. Many points must be used to include all of the local structures that may impact the distortion of the feature being optimized. However, each of these neighboring local structures must also be optimized. The ideal situation is to consider the entire chip within a single calculation. However, this also dramatically increases the computational requirement. Therefore, this FD method has limited use.
[0043] The spatial domain (SD) OPC calculations are based on the spatial properties of the features. The edges and vertices of the features on the exposure mask, such as polygons or rectangles, are modified in an effort to minimize the difference between the actual structure realized using the corrected exposure mask and the desired structure. There are several steps to this method.
[0044] The candidate control points, or evaluation points, on the edges and vertices are determined based on current design rules. An example of a flow is:
[0045] SD-1. For every edge, or fragment of an edge, an edge placement error (EPE) is determined by a model of the optical system. Calculations are performed using system kernels and their convolution with the exposure mask region around each edge.
[0046] SD-2. Upon determining an edge placement error, an edge fragment may be “pushed” or “pulled” in an attempt to reduce the error.
[0047] SD-3. The simulations and adjustments are repeated several times for each edge fragment until the edge placement error is within the acceptable range for all features on the chip.
[0048] The spatial domain OPC methods enjoy several benefits over the frequency domain methods. The light effects are generally localized to the features in the immediate vicinity of the feature under consideration. Therefore, the size of a specific calculation may be smaller. However, the same calculation must be made for all of the feature groups on the chip.
[0049] Currently, typical solutions to the OPC computational problem include the use of large systems of multi-CPU computers. This increases the cost of the system and contributes to the cost of the chip. CPUs are typically designed for minimal latency and to address general purpose programs. This hardware configuration will be defined here as a “homogeneous configuration” meaning that the various computational tasks are executed by equivalent processors.
[0050] An alternative hardware configuration includes a cooperative collection of specialized processing units where each processing unit may be well suited for a specific type of computation. This hardware configuration will be defined here as a“heterogeneous configuration” meaning that the various computational tasks are executed by different, typically specialized, processors. As an example, GPUs are designed specifically for high throughput on specialized types of problems found in graphics processing that require a large number of arithmetic calculations with a relatively small number of memory access steps. Other specialized processors may be designed to handle other types of data or computational problems. Allocating the various portions of the OPC computations to specialized processors may improve the throughput, increase the efficiency, lower the cost, and improve the results of the computation.
[0051] GPUs may be designed for fast graphics processing. The data may be organized into a stream where a stream is an ordered set of data of the same data type. Operations, procedures, methods, algorithms, and the like that may be applied to entire streams of data are typically called kernels. Kernels are very efficient because they depend only on their input. Internal computations within the kernel are independent of other elements of the stream. Therefore, GPUs may be designed for parallel processing, memory efficiency, and high throughput for specific problems.
[0052] GPUs typically have hardware blocks that may be specifically designed for certain types of problems (e.g., specific kernels may be implemented in hardware). As an example, hardware blocks may be designed to implement various types of vector or matrix computations, or both. As an example, graphics data is typically four-dimensional referring to the channel value of the red, green, and blue pixels (referred to as RGB) and the opacity value (typically referred as alpha or A). Therefore, GPUs have been designed to process four-dimensional (RGBA) data very quickly and very efficiently.
[0053] CPU-based approaches to improve the OPC procedures typically employ multi-CPU systems as mentioned previously. Such approaches typically have attempted to increase the computational efficiency by dividing the computation into parallel parts at the task level. However, they are not able to exploit additional parallelism at the instruction level due to their general purpose design.
[0054] OPC calculations are inherently graphics problems. In one embodiment of the present invention, graphics data in the form of rectangles or polygons may be sent by one or more CPUs to one or more GPUs. The GPUs may be designed to efficiently implement one or more kernels for the efficient execution of the steps of the OPC method described previously.
[0055] Typically, the following functions may be implemented with task level parallelism:
[0056] (i) Allocation of vertex shaders or vertex processors for evaluation point selection (step SD-1).
[0057] (ii) Allocation of vertex shaders for modification of evaluation points and their location (step SD-3).
[0058] (iii) Allocation of rasterization for determining the evaluation points based on 1-D and 2-D cost functions (step SD-1).
[0059] (iv) Allocation of pixel shaders or fragment processors, or both, for intensity calculations using fast kernel lookups or fast kernel calculations (step SD-2).
[0060] (v) Allocation of fragment tests such as depth tests for area query and tagging of edges and edge fragments (step SD-2). Other common fragment tests that may be used include scissor tests, alpha tests, stencil tests, blending tests, dithering tests, logical operations, and the like.
[0061] In a GPU, vertex shaders or vertex processors are a programmable unit that operates on incoming vertex values and their associated data. Rasterization is the conversion of both geometric and pixel data into fragments. Pixel shaders or fragment processors are programmable units that operate on fragment values and their associated data. Depth tests are, for each pixel, the depth buffer keeps track of the distance from the viewpoint and the object occupying that pixel. Then, if the specified depth test passes, the incoming depth value replaces the value already in the depth buffer.
[0062] Typically, the following functions may be implemented with evaluation point parallelism:
[0063] (i) Each pixel shader computes one evaluation point in parallel (step SD-2).
[0064] (ii) Efficient use of four-dimensional pixel values and pixel operations for fast kernel computation (step SD-2).
[0065] Typically, the following functions may be implemented with instruction level parallelism:
[0066] (i) Mapping of convolution tables as texture maps/image maps (step SD-2).
[0067] (ii) Use of texture interpolation for optimizing texture cache use (step SD-2).
[0068] Texture maps or image maps are rectangular arrays of data (e.g., color data, luminance data, color and alpha data, and the like). Texture interpolation is mathematical interpolation between texture map or image map data.
[0069] Typically, the following special hardware functions may be implemented for searching and region query:
[0070] (i) Depth processor for selection of evaluation points (step SD-1).
[0071] (ii) Single-input multiple-data (SIMD) video processor for computing error terms (step SD-3).
[0072] (iii) Multiple-input multiple-data (MIMD) video processor for computing error terms (step SD-3).
[0073] A depth processor is a programmable unit that operates on incoming fragment or pixel values and their associated data. Video processor is a processor that performs video decoding or encoding operations on video data. The processor may be of a single-instruction multiple-data (SIMD) or multiple-instruction multiple-data (MIMD) type.
[0074] Thus, a subset of OPC calculations will map very efficiently onto typical GPU hardware and typical GPU programming features. Therefore, GPUs may share computations with CPUs to more efficiently manage OPC problems leading to higher throughput, lower cost, improved efficiency, and the like.
[0075] FIG. 3 is a schematic representation of typical procedures for performing a typical OPC method on commercial GPU. The specific case illustrated uses an Nvidia GeForce® GPU processor, but the present invention may generally apply to any commercial GPU or similar device.
[0076] Various operations of an OPC flow are executed using a graphics processor 300 . Some steps of an OPC flow include a geometric operation 309 , rectangle fragmentation 310 , intensity calculation 311 , area search 312 , and placement error or edge placement error (EPE) calculation 313 . Geometric operations are. Rectangle fragmentation operations are. Intensity calculations are. Area search are. Placement error or EPE calculations are.
[0077] The graphics processor may be a single integrated circuit or multiple integrated circuits. For example, all the GPU components shown in the figure (e.g., blocks 301 , 302 , 303 , 304 , 305 , 306 , 307 , and 308 ) may reside on a single integrated circuit. Or any combination of components may reside on one integrated circuit and other components reside on one or more other integrated circuits. Also a single integrated circuit may include one or more graphics processor cores.
[0078] In a graphics processor 300 , there are one or more vertex processors 301 , which are connected to a triangle setup block 302 . A vertex processor is responsible for running the vertex shaders. The input for a vertex shader is the vertex data, namely its position, color, normals, an so forth. In a vertex shader, one can write code for tasks such as: vertex position transformation using the model view and projection matrices; normal transformation, and if required its normalization; texture coordinate generation and transformation; lighting per vertex or computing values for lighting per pixel; and color computation.
[0079] The triangle set up block does. The triangle set-up block is connected to a shader instruction dispatch 303 . The shader instruction dispatch does. The shader instruction dispatch is connected to one or more fragment processors 304 .
[0080] The fragment processor is where the fragment shaders run. This unit is responsible for operations like: computing colors, and texture coordinates per pixel; texture application; fog computation; and computing normals if one wants lighting per pixel. The inputs for a fragment processor this unit are typically the interpolated values computed in the previous stage of the pipeline such as vertex positions, colors, normals, and so forth.
[0081] The fragment processor is connected to a fragment crossbar 305 . The fragment crossbar does. The fragment crossbar is connected to a stencil buffer 306 . The stencil does. The stencil is connected to one or more memory partitions 307 .
[0082] The graphics processor may have one or more video processors 308 . The video processor does. The video processor is connected to. Any combination of the components shown in graphics processor 300 may included one integrated circuit. For example, a graphics processing unit integrated circuit may include a vertex processor unit and a fragment processor unit. The graphics processing unit integrated circuit may include a vertex shader unit and a stencil buffer unit.
[0083] In FIG. 3 , the geometric operations and rectangle fragmentation (step SD-1) may map to the vertex processor hardware blocks of the GPU. The intensity calculation, area search, and edge placement error (EPE) calculation steps (step SD-2 through SD-4) may map to the fragment processor and depth filter hardware blocks of the GPU. EPE calculation may simply be referred to as placement error calculations, especially in embodiments of the invention where edges are not used.
[0084] Geometric operations may be performed in the CPU (outside the GPU), vertex processor, or fragment processor. Fragmentation operations may be performed in the CPU, vertex processor, or fragment processor. Intensity calculations may be performed in the fragment processor. Area search may be performed in the fragment processor or stencil. EPE calculations may be performed in the fragment processor or video processor. In OPC procedure, any combination of these operations may be performed with each other.
[0085] For example, the fragment processor may perform the geometric operations, fragmentation operations, intensity calculations, area search, and EPE calculations. In a further embodiment, the geometric operations and fragmentation operations may be performed by the CPU and the intensity calculations, area search, and EPE calculations may be performed in the GPU. In a further embodiment, the geometric operations and fragmentation operations may be performed by the vertex processor of the GPU and the intensity calculations, area search, and EPE calculations may be performed by the fragment processor of the GPU. In an embodiment, the area search may be performed in the stencil buffer of the GPU. In an embodiment, the EPE calculation may be performed using the video processor.
[0086] Positions of geometries of the layout may be represented in the four-dimensional space (RGBA) format provided in the GPU. In other words, a two-dimensional trapezoidal shape of the data is represented as four-channel data in the graphics processing unit. In specific implementations, the trapezoid may be a rectangle or square. In an embodiment, two opposite corners of a two-dimensional trapezoidal shape of the data is represented in a RGBA color space format in the graphics processing unit. For example, X 1 will be R, Y 1 will be G, X 2 will be B, and Y 2 will be A. The GPU will operate on the data stored in such a four-dimensional format.
[0087] In another embodiment, X and Y coordinates for a corner, a width, and a height of a two-dimensional trapezoidal shape of the data is represented in a RGBA color space format in the graphics processing unit. For example, X 1 will be R, Y 1 will be G, W will be B, and H will be A. The GPU will operate on the data stored in such a four-dimensional format.
[0088] In another embodiment, X and Y coordinates for a corner, a change in X, and a change in Y of a two-dimensional trapezoidal shape of the data is represented in a RGBA color space format in the graphics processing unit. For example, X 1 will be R, Y 1 will be G, delta X will be B, and delta Y will be A. The GPU will operate on the data stored in such a four-dimensional format.
[0089] In another embodiment, X and Y coordinates for a corner, an angle, and a scalar of a two-dimensional trapezoidal shape of the data is represented in a RGBA color space format in the graphics processing unit. For example, X 1 will be R, Y 1 will be G, theta will be B, and r will be A. The GPU will operate on the data stored in such a four-dimensional format.
[0090] There representations of OPC data in a GPU are merely examples of some representations that may be used. In other embodiments of the invention, other representation schemes may be used.
[0091] In an embodiment, a system of the invention includes: a computing system having at least one central processing unit and at least one graphics processing unit; a user interface for interacting with the computer system; a computer readable medium including data describing the size and placement of features to be formed on a photolithography exposure mask used to manufacture semiconductor devices; a computer readable medium including optical proximity correction calculation procedures for acting upon the data, where at least a portion of the optical proximity correction calculation procedures are executed using the graphics processing unit; and output devices for displaying the results of applying the optical proximity correction calculation procedures executed using the graphics processing unit upon the data. The graphics processing unit may include a vertex processor unit and a fragment processor unit. The graphics processing unit may include a vertex shader unit and a stencil buffer unit.
[0092] In an embodiment, there may be multiple CPUs and GPUs that perform the OPC calculations. A system of the invention may include multiple nodes which are connected with high speed interface or connections between them. This interface may include, for example, a PCI Express bus, AGP bus, front side bus, Ethernet, or the Internet, or a combination of these. Each node has one or multiple CPUs or one or more GPUs, or any combination of CPU and GPUs. Each node may or may not be equipped with a secondary storage area such as hard disk floppy, CD writer, or other. OPC software of the invention may be run on any of the machines.
[0093] For example, there may be a master program that runs on any subset of the nodes of the system. The master program may be executed on only one of the nodes. Data which OPC procedures of the invention will act upon may be associated with any node of the system. The master program may direct other nodes of the system to perform OPC calculations. The master program may coordinate operations of the computing system. The OPC procedures or data, or both, may be transferred from one node to any other node of the system. Results may then be passed back to the master program, where individual results are combined.
[0094] The graphics processing units and the optical proximity correction calculation procedures may include at least one of:
[0095] Procedures for allocation of vertex shaders for evaluation point selection.
[0096] Procedures for allocation of vertex shaders for modification of evaluation points and their location.
[0097] Procedures for allocation of rasterization for determining the evaluation points based on one-dimensional and two-dimensional cost functions.
[0098] Procedures for allocation of pixel and vertex shaders for intensity calculations including spatial or frequency-domain approaches to calculate intensity or electromagnetic fields, or a combination, in air or in the other media including resist materials and on a chip surface.
[0099] Procedures for allocation of pixel shaders for intensity and electromagnetic field calculations in air and in the resist material as well as other related locations on the chip surface including memory lookups or fast kernel calculations.
[0100] Procedures for allocation of pixel shaders for intensity calculations using other methods of calculating intensity or electromagnetic fields, or a combination, such as convolution in frequency domain using fast fourier transforms and inverse fourier transforms or any other transforms to the same effect in air or in the resist material as well as other related locations on the chip surface.
[0101] Procedures for allocation of pixel shaders for intensity calculations using fast kernel lookups or fast kernel calculations.
[0102] Procedure for allocation of g pixel shaders for intensity calculations using light lookups or light calculations.
[0103] Procedures for allocation of depth filters for area query and tagging of edges and edge fragments.
[0104] Procedures for pixel shader computation of evaluation points.
[0105] Procedures for mapping of convolution tables as texture maps.
[0106] Procedures for the use of texture interpolation for optimizing texture cache use.
[0107] Procedures for the use of a depth processor for the selection of evaluation points.
[0108] Procedures for the use of a single input multiple data (SIMD) video processor for computing error terms.
[0109] In a specific embodiment of the invention, a procedure splits the given layout information into two-dimensional subregions, where these regions overlaps with each other. There may be multiple such procedures running on separate nodes of a system. This information, as well as whole or partial layout information, is sent to each node where the nodes perform OPC-related calculation. The results of the calculations are collected (such as at a single node) where the information is stitched together by removing the overlapping regions. Stitching may be performed using a single node or multiple nodes in parallel.
[0110] In a specific embodiment, a procedure includes splitting a layout into a number of nonrectangular two-dimensional overlapping regions. The method splits the layout into overlapping two-dimensional rectilinear or polygonal spaces, sending whole or portions of the region or regions to each node. The method may perform OPC corrections (or reticle corrections) without sending or sharing any information between nodes. Portions or complete regional information may be provided to each node for parallel computation.
[0111] FIG. 5 shows partitioning of layout data and where each partition has overlapping regions from adjacent partitions. In a technique of the invention, instead of performing calculations on an entire layout, the layout is divided or partitioned into a number of subregions. In this case, each subregion is two dimensional. In particular, a technique partitions a layout 503 into a number of regions or subregions. Although each region is shown as been rectangular in this figure, each partition may have any shape such as square, trapezoid, any polygonal, or other.
[0112] According to a specific approach, the data in each two-dimensional subregion is operated on by one or more computing nodes of the system. As discussed above, each node may include CPUs or GPUs, or both. In a specific implementation, each node has a GPU which performs OPC calculations on a specific subregion of the layout. Calculations may be performed on a number of subregions in parallel, which will speed up the calculations. Generally, the greater the number of nodes, the faster the calculations may be performed since more calculations will be performed in parallel. After a node has completed its calculations, the output results are transferred back to a calling node (such as the node where a master program is running) or to another specific location. Then, one or more computing nodes will assembly the output results for the individual partitions together to provide the OPC calculation output for the complete layout data.
[0113] In a specific implementation ofthe invention, each subregion is sent to a node including some overlapping region data from adjacent partitions. For example, for a corner partition, a subregion (see subregions 505 and 509 ) sent to a node will include overlap information from two adjacent sides. For an edge partition (not corner), subregion 507 sent to a node will include overlap information from three adjacent regions. For a middle partition, the subregion 511 will include overlap information from four adjacent regions. When performing the OPC calculations, the nodes will use these subregions including overlap data.
[0114] In a specific implementation, after the OPC calculations, the output from each node will be simply the output data for the subregion itself, without any overlap regions. Therefore, in this case, each node with have the overlap region as the input data, but not in the output data. This approach leads to more accurate results in the OPC calculations.
[0115] In a specific embodiment, the computation of the lithography process simulation for OPC and RET purposes which includes the mask preparation related calculations, EAPSM and AAPSM related calculations such as electromagnetic field computation to take into account the thick mask effects, the chemical processes happening during lithography processes including the exposure process, the postbake process, the chemical amplification process, the development process all or partially computed in pixel shaders or in combination of pixel and vertex shaders.
[0116] FIG. 4 depicts an illustrative computer system pertaining to various embodiments of the present invention. In some embodiments, the computer system includes a server 401 , display 402 , one or more input interfaces 403 , and one or more output interfaces 404 , all conventionally coupled by one or more buses 405 . Examples of suitable buses include PCI-Express®, AGP, PCI, ISA, and the like.
[0117] The computer system may include any number of graphics processors. The graphics processor may reside on the motherboard such as being integrated with the motherboard chipset. One or more graphics processors may reside on external boards connected to the system through a bus such as an ISA bus, PCI bus, AGP port, PCI Express, or other system buses. Graphics processors may on separate boards, each connected to a bus such as the PCI Express bus to each other and to the rest of the system. Further, there may be a separate bus or connection (e.g., Nvidia SLI or ATI CrossFire connection) by which the graphics processors may communicate with each other. This separate bus or connection may be used in addition to or in substitution for system bus.
[0118] The server 401 includes one or more CPUs 406 , one or more GPUs 407 , and one or more memory modules 412 . Each CPU and GPU may be a single core or multiple core unit. Examples of suitable CPUs include Intel Pentium®, Intel Core™ 2 Duo, AMD Athlon 64, AMD Opteron®, and the like. Examples of suitable GPUs include Nvidia GeForce®, ATI Radeon®, and the like. The input interfaces 403 may include a keyboard 408 and a mouse 409 . The output interface 404 may include a printer 410 .
[0119] The communications interface 411 is a network interface that allows the computer system to communicate via a wireless or hardwired network. The communications interface 411 , may be coupled to a transmission medium (not shown), such as a network transmission line, for example, twisted pair, coaxial cable, fiber optic cable, and the like. In another embodiment, the communications interface 411 , provides a wireless interface, that is, the communication interface 411 uses a wireless transmission medium. Examples of other devices that may be used to access the computer system via communications interface 411 include cell phones, PDAs, personal computers, and the like (not shown).
[0120] The memory modules 412 generally include different modalities, illustratively semiconductor memory, such as random access memory (RAM), and disk drives as well as others. In various embodiments, the memory modules 412 , store an operating system 413 , data structures 414 , instructions 415 , applications 416 , and procedures 417 .
[0121] Storage devices may include mass disk drives, floppy disks, magnetic disks, optical disks, magneto-optical disks, fixed disks, hard disks, CD-ROMs, recordable CDs, DVDs, recordable DVDs (e.g., DVD-R, DVD+R, DVD-RW, DVD+RW, HD-DVD, or Blu-ray Disc), flash and other nonvolatile solid-state storage (e.g., USB flash drive), battery-backed-up volatile memory, tape storage, reader, and other similar media, and combinations of these.
[0122] In various embodiments, the specific software instructions, data structures, and data that implement various embodiments of the present invention are typically incorporated in the server, 401 . Generally, an embodiment of the present invention is tangibly embodied using a computer readable medium, for example, the memory, and includes of instructions, applications, and procedures which, when executed by the processor, causes the computer system to utilize the present invention, for example, the collection and analysis of data, pixelating structures, determining edge placement errors, moving edge fragments, optimizing edge fragment placements, and the like. The memory may store the software instructions, data structures, and data for any of the operating system, the data collection application, the data aggregation application, the data analysis procedures, and the like in semiconductor memory, in disk memory, or a combination of these.
[0123] A computer-implemented or computer-executable version of the invention may be embodied using, stored on, or associated with computer-readable medium. A computer-readable medium may include any medium that participates in providing instructions to one or more processors for execution. Such a medium may take many forms including, but not limited to, nonvolatile, volatile, and transmission media. Nonvolatile media includes, for example, flash memory, or optical or magnetic disks. Volatile media includes static or dynamic memory, such as cache memory or RAM. Transmission media includes coaxial cables, copper wire, fiber optic lines, and wires arranged in a bus. Transmission media can also take the form of electromagnetic, radio frequency, acoustic, or light waves, such as those generated during radio wave and infrared data communications.
[0124] For example, a binary, machine-executable version, of the software of the present invention may be stored or reside in RAM or cache memory, or on a mass storage device. The source code of the software of the present invention may also be stored or reside on mass storage device (e.g., hard disk, magnetic disk, tape, or CD-ROM). As a further example, code of the invention may be transmitted via wires, radio waves, or through a network such as the Internet.
[0125] The operating system may be implemented by any conventional operating system comprising Windows® (registered trademark of Microsoft Corporation), Unix® (registered trademark of the Open Group in the United States and other countries), Mac OS® (registered trademark of Apple Computer, Inc.), Linux® (registered trademark of Linus Torvalds), as well as others not explicitly listed here.
[0126] In various embodiments, the present invention may be implemented as a method, system, or article of manufacture using standard programming or engineering techniques, or both, to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” (or alternatively, “computer program product”) as used in this application is intended to encompass a computer program accessible from any computer readable device, carrier or media. In addition, the software in which various embodiments are implemented may be accessible through the transmission medium, for example, from a server over the network. The article of manufacture in which the code is implemented also encompasses transmission media, such as the network transmission line and wireless transmission media. Thus the article of manufacture also includes the medium in which the code is embedded. Those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention.
[0127] The computer system illustrated in FIG. 4 is not intended to limit the present invention. Other alternative hardware environments may be used without departing from the scope of the present invention.
[0128] This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and many modifications and variations are possible in light of the teaching above. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims. | Optical proximity correction techniques performed on one or more graphics processors improve the masks used for the printing of microelectronic circuit designs. Execution of OPC techniques on hardware or software platforms utilizing graphics processing units. GPUs may share the computation load with the system CPUs to efficiently and effectively execute the OPC method steps. | 6 |
[0001] The invention relates to a transmitter for a synchronising assembly of a manual transmission, having a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The invention also relates to a method for producing a transmitter for a synchronising assembly of a manual transmission.
BACKGROUND OF THE INVENTION
[0002] A synchronising assembly of a manual transmission, as used in particular in motor vehicles, is used, in general terms, to establish a rotationally-fixed connection between a transmission shaft and a gear wheel or toothed wheel arranged on the transmission shaft as an idler wheel. In a first step of the gear-shifting process, the synchronising assembly ensures that the rotational speed of the gear wheel to be shifted matches the rotational speed of the transmission shaft. In a second step, a rotationally-fixed connection is established between the transmission shaft and the gear wheel. The corresponding gear is then shifted.
[0003] A widely used type of synchronising assembly is known under the name “BorgWarner synchronisation”. This synchronising assembly uses a shift collar which is arranged on a synchronising body in a rotationally-fixed but axially displaceable manner, said body being connected to the transmission shaft for conjoint rotation therewith. The shift collar can be displaced from an initial position in the axial direction to a gear wheel. A synchronising ring is initially activated hereby which synchronises the rotational speed of the gear wheel with the rotational speed of the transmission shaft. As soon as this process is complete, the shift collar can be further displaced in the axial direction until it establishes a rotationally-fixed connection with the corresponding gear wheel.
[0004] As an alternative to this type of synchronising assembly, a type which uses the transmitter mentioned in the introduction is known. An example of this can be seen in DE 10 2010 036 278 A1. In general terms, the transmitter combines the synchronising body and the shift collar in one component which is mounted so as not to rotate relative to the transmission shaft and can be displaced in the axial direction. If the transmitter is displaced in the axial direction from a neutral position, a synchronising ring (or even an assembly consisting of a plurality of synchronising rings) is initially activated, whereby the rotational speed of the corresponding gear wheel is synchronised with the rotational speed of the transmission shaft. In a second step, the transmitter can then be interconnected, whereby a rotationally-fixed connection is established between the transmission shaft and the corresponding gear wheel.
[0005] The object of the invention is to provide a transmitter which can be produced at low cost.
BRIEF DESCRIPTION OF THE INVENTION
[0006] In order to achieve this object, a transmitter is provided which has a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The clutch disk and the transmitter disk are fixedly connected together by local welding points. These can be produced quickly, reliably and at low cost, for example by resistance welding. Since the torque is transmitted from the transmission toothed wheels to the transmission shaft substantially directly via the clutch disks and not via the transmitter disk, the welding points are also not subjected to any particularly high loads.
[0007] Projections are preferably provided which form the welding points. This ensures that the welding points are produced precisely at the desired positions.
[0008] In accordance with a preferred embodiment, spacers are provided, on which the projections are formed, in particular on the transmitter disk. The spacers allow a pressure piece to be arranged in the transmitter disk, the dimensions of which pressure piece are larger in the axial direction than the thickness of the transmitter disk. This allows in particular a comparatively robust compression spring to be arranged in the transmitter disk.
[0009] In order to achieve the above-mentioned object, a method for producing a transmitter for a synchronising assembly of a manual transmission is also provided in accordance with the invention, said method comprising the following steps: initially, a clutch disk and a transmitter disk are provided. Then, the clutch disk and the transmitter disk are fastened together by means of projection welding. Then, the thus formed assembly is hardened. This sequence of welding and hardening ensures that the material has, during welding, the optimum properties therefor.
[0010] The assembly can either be freely hardened, i.e. hardened and quenched or it is also possible for the assembly to be hardened on a mandrel which, for example, engages into an internal toothed arrangement of the clutch disk and thus limits the distortion due to hardening at that location.
[0011] In accordance with a preferred embodiment, provision is made that the transmitter disk is provided with at least one recess, and that after the assembly is hardened a pressure piece is mounted in the recess. The pressure piece can be inserted into the recess allocated thereto in an extremely simple manner in mechanical terms, wherein it is optionally guided between the clutch disks.
[0012] In accordance with a preferred embodiment of the invention, provision is made that the pressure piece is clipped into the recess. This ensures that the pressure piece remains in the recess allocated thereto after being assembled without any further aids.
[0013] In accordance with a preferred embodiment of the invention, provision is made that the pressure piece is provided with a base part and a guide part, wherein the base part is located between two clutch disks which are arranged on sides of the transmitter disk facing away from each other, and that the guide part is guided in the axial direction between edges of the recess which are opposite one another in the circumferential direction. This design produces a particularly precise guidance of the pressure piece in the recess, whereby the shifting behaviour is optimised.
[0014] Advantageous embodiments of the invention are apparent from the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will be described hereinafter with the aid of an embodiment which is illustrated in the attached drawings. In the drawings:
[0016] FIG. 1 shows a schematic longitudinal sectional view of a synchronising assembly having a transmitter in accordance with the invention;
[0017] FIG. 2 shows an exploded view of the synchronising assembly of FIG. 1 ;
[0018] FIG. 3 shows a sectional view along plane of FIG. 1 ;
[0019] FIG. 4 shows a sectional view along plane IV-IV of FIG. 3 ;
[0020] FIG. 5 shows a sectional view along plane V-V of FIG. 3 ;
[0021] FIG. 6 shows an enlarged view of the section VI of FIG. 3 ;
[0022] FIG. 7 a shows a sectional view along plane VII-VII of FIG. 3 ;
[0023] FIGS. 7 b to 7 e show different embodiment variants of the region marked with VII in FIG. 7 a;
[0024] FIG. 8 shows a perspective view of the transmitter disk of the transmitter in accordance with the invention having pressure pieces mounted therein;
[0025] FIG. 9 shows a perspective view of a pressure piece which is used in the transmitter in accordance with the invention;
[0026] FIG. 10 shows a perspective view of the guide part of the pressure piece of FIG. 9 ;
[0027] FIG. 11 shows a bottom view of the guide part of FIG. 10 ;
[0028] FIG. 12 shows a side view of the guide part of FIG. 10 ;
[0029] FIG. 13 shows a plan view of the guide part of FIG. 10 ;
[0030] FIG. 14 shows a perspective view of the base part of the pressure piece of FIG. 9 ;
[0031] FIG. 15 shows a bottom view of the base part of FIG. 9 ;
[0032] FIG. 16 shows a side view of the base part of FIG. 9 ;
[0033] FIG. 17 shows a plan view of the base part of FIG. 9 ;
[0034] FIG. 18 shows a side view of the transmitter disk;
[0035] FIG. 19 shows a sectional view along line XIX-XIX of FIG. 18 ;
[0036] FIG. 20 shows a sectional view along plane XX-XX of FIG. 18 ;
[0037] FIG. 21 shows a sectional view along plane XXI-XXI of FIG. 18 ; and
[0038] FIG. 22 shows a sectional view along plane XXII-XXII of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1 schematically shows a synchronising assembly which comprises two transmission toothed wheels 1 , 2 which can each be connected to a transmission shaft 3 for conjoint rotation therewith depending upon the shifted gear. For this purpose, a transmitter 10 is provided which can be adjusted in the axial direction relative to the transmission shaft 3 .
[0040] Where the terms “axial” or “radial” are used hereinafter, they refer to the rotational axis of the transmission shaft 3 and of the transmitter 10 .
[0041] The basic design of the synchronising assembly is explained hereinafter with reference to FIGS. 1 to 5 , whilst details will be explained further hereinafter with reference to FIGS. 6 to 22 .
[0042] The transmitter 10 comprises a transmitter disk 12 which is provided with a clutch disk 14 on each of its two side surfaces. Each clutch disk 14 comprises, on its radially inner circumference, a transmission shaft toothed arrangement 16 and, on its radially outer circumference, a clutch toothed arrangement 18 (see in particular FIG. 2 ).
[0043] The transmission shaft toothed arrangements 16 of the clutch disks 14 are accommodated on an external toothed arrangement 20 of a transmitter sleeve 22 in a rotationally-fixed but axially displaceable manner. In turn, the transmitter sleeve 22 is arranged on the transmission shaft 3 in a rotationally-fixed manner. For this purpose, the transmitter sleeve 22 can be provided with an internal toothed arrangement 24 (see in particular FIGS. 3 to 5 ).
[0044] The clutch toothed arrangement 18 of each clutch disk 14 is provided so as to co-operate with a gear wheel clutch toothed arrangement 26 allocated thereto and provided on the transmission toothed wheels 1 , 2 . In the illustrated exemplified embodiment, each gear wheel clutch toothed arrangement 26 is provided on the inner surface of a friction ring 28 which is provided on its outer side with a slightly conical friction surface 30 . Each friction ring 28 is connected, e.g. welded or soldered, to the transmission toothed wheel 1 , 2 allocated thereto for conjoint rotation therewith.
[0045] Arranged on the transmitter disk 12 are two synchronising rings 32 which lie one on either side of the transmitter disk 12 and are provided so as to co-operate with the friction surfaces 30 of the friction rings 28 . For this purpose, the synchronising rings 32 are provided with a friction lining 34 on their inner surface.
[0046] The synchronising rings 32 are basically connected to the transmitter disk 12 for conjoint rotation therewith but they can also rotate relative thereto about a small angular range. Furthermore, the synchronising rings 32 are attached in the axial direction to the transmitter disk 12 but they can also be adjusted to a certain extent in the axial direction starting from a centre or initial position.
[0047] Each synchronising ring 32 is provided with three different types of lugs which extend through allocated openings, recesses or apertures in the transmitter disk, or at least extend into same: connecting lugs 36 , 37 , stop lugs 38 and locking lugs 40 .
[0048] The connecting lugs 36 , 37 are used to mechanically connect the two synchronising rings 32 to each other in the axial direction. For this purpose, each synchronising ring 32 has a connecting lug 36 which has a wide head at its free end and transitions into the synchronising ring-side section of the connecting lug 36 via a narrower neck.
[0049] Each connecting lug 37 has an aperture which has a larger section adapted to the dimensions of the head of the connecting lug 36 and a narrower section adapted to the dimensions of the neck of the connecting tug 36 .
[0050] The connecting lugs 36 , 37 extend, when engaged with each other, through two openings 42 , allocated thereto, in the transmitter disk. The width of the openings 42 in the circumferential direction is greater than the width of the connecting lugs 36 , 37 in the circumferential direction.
[0051] The stop lugs 38 have a constant width and extend into apertures 44 which are likewise provided in the transmitter disk 12 . The width of the apertures 44 in the circumferential direction is slightly greater than the width of the stop lugs 38 in the circumferential direction.
[0052] The locking lugs 40 each extend into a recess 46 in the transmitter disk 12 . The mutually facing ends of the locking lugs 40 in the initial position are located opposite each other and centrally within the recess 46 (see in particular FIG. 4 ).
[0053] Each locking lug 40 comprises, in proximity to its free end, two locking surfaces 48 which face away from each other and extend in an inclined manner relative to the extension direction of the locking lugs 40 . In this case, the locking surfaces 48 form, with an extension of the outer edges of the locking lugs 40 , an angle in the order of magnitude of 60°.
[0054] The locking surfaces 48 co-operate with the edges 50 of the corresponding recess 46 , which edges are opposite each other and extend in parallel with each other, and, more specifically, the locking surfaces each co-operate with a bevel 52 which is provided on the corresponding edge. The orientation of the bevels 52 corresponds to the orientation of the locking surfaces 48 so that these can lie flat against each other.
[0055] The locking lugs 40 comprise, on the radially inner side of each of their free ends, a centring bevel 54 (see in particular FIG. 4 ), on which an outwardly directed pressure surface 56 of a pressure piece 58 engages.
[0056] Each pressure piece 58 comprises a guide part 60 which is held between the edges 50 of the corresponding recess 46 in the axial direction, a base part 62 which is arranged on the radially inner end of the recess 46 , and a compression spring 64 which exerts a force upon the guide part 60 and the base part 62 , said force intending to move the guide part 60 away from the base part 62 .
[0057] As can be seen in particular in FIG. 2 , the transmitter comprises four locking lugs 40 per synchronising ring 32 , which lugs are evenly spaced apart from each other in the circumferential direction, and two connecting lugs 36 , 37 which lie diametrically opposite one another, and two stop lugs 38 which lie diametrically opposite one another. The diameter defined by the two connecting lugs 36 , 37 is perpendicular to the diameter defined by the two stop lugs 38 . In other words: the connecting lugs and the stop lugs are arranged so as to be staggered with respect to one another by an angle of 90°.
[0058] The process of shifting a gear and synchronising the rotational speeds of the transmission shaft and of the transmission toothed wheel to be shifted is basically performed in the same manner as described in DE 10 2010 036 278 A1: if a gear is to be shifted, the transmitter disk 12 is displaced in the axial direction by means of an actuating device (not shown herein). The two synchronising rings 32 connected together are entrained in the axial direction because the pressure surfaces 56 of the pressure pieces 58 mounted on the transmitter disk 12 lie between the two V-shaped centring bevels 54 and the spring force provided by the compression springs 64 produces sufficient friction.
[0059] As soon as the synchronising ring 32 comes into engagement with the friction surface 30 , allocated to the transmission toothed wheel to be shifted, the synchronising ring (assuming a difference in rotational speed between the transmission toothed wheel and the transmission shaft) is entrained in the circumferential direction until one of the outer edges of each of the two stop lugs 38 comes to lie against the edge of the corresponding aperture 44 in each case. The position of the synchronising rings is hereby defined in the circumferential direction.
[0060] If, in this state, the transmitter disk 12 is further displaced in the axial direction, it is displaced axially relative to the synchronising rings 32 because the active synchronising ring 32 is supported in the axial direction on the friction surface 30 of the transmission toothed wheel to be shifted. By way of this axial displacement of the transmitter disk 12 relative to the synchronising ring 32 , one of the bevels 52 at the edge of each recess 46 comes to lie against one of the locking surfaces 48 on each of the locking lugs 40 , and in particular the ones which have been moved towards each other owing to the relative movement between the synchronising rings 32 and the transmitter disk 12 .
[0061] The transmitter disk 12 can only then be further adjusted in the axial direction if the synchronising rings 32 can, via the mutually co-operating locking surfaces 48 of the synchronising rings and bevels 52 of the transmitter disk, be rotated back in the circumferential direction to the extent that the locking surfaces 48 no longer lie against the bevels 52 but rather the outer edges of the locking lugs 40 extending in the axial direction slide along the edges 50 of the recesses 46 . However, it is only possible to re-adjust the synchronising ring 32 in the circumferential direction (expressed simply) when the rotational speeds of the transmission toothed wheel to be shifted and the transmission shaft match one another. Specifically: the synchronising ring 32 can then be unlocked if the unlocking moment (reverse torque), resulting from the shifting force and the locking geometry (bevel angle and coefficient of friction) is greater than the synchronising moment on the friction surface of the synchronising ring.
[0062] If the rotational speeds of the transmission toothed wheel and the transmission shaft match one another, the synchronising rings 32 are rotated slightly in the circumferential direction (owing to the effect of the bevels 52 on the locking surfaces 48 ), and therefore the transmitter disk 12 can be further shifted in the axial direction. The guide parts 60 of the pressure pieces 58 yield radially inwards because they are adjusted inwardly by the centring bevels 54 .
[0063] The transmitter disk 12 is adjusted in the axial direction to the extent that the clutch toothed arrangement 18 of the clutch disk 14 located at the front in the adjusting direction engages into the corresponding gear wheel clutch toothed arrangement 26 . As a result, a rotationally-fixed connection is established from the transmission shaft 3 , via the transmitter sleeve 22 , the transmission shaft toothed arrangement 16 , the clutch disk 14 , the clutch toothed arrangements 18 and the gear wheel clutch toothed arrangement 26 , to the corresponding transmission toothed wheel.
[0064] The design of the pressure pieces 58 and their attachment in the recesses 46 of the transmitter disk 12 will be explained hereinafter with reference to FIGS. 6 to 17 .
[0065] The guide part 60 of each pressure piece 58 consists of synthetic material and is formed in particular as an injection moulded part. It comprises a cross-bar 70 (see in particular FIGS. 9, 10 and 12 ), wherein two latching arms 72 extend in parallel with each other in the same direction from the ends of the cross-bar which face away from each other. The cross-bar 70 is provided with the pressure surface 56 on the side opposite the latching arms 72 . This pressure surface is slightly curved, wherein the radius of curvature which determines the curvature in the circumferential direction is on a central plane M on the side towards which the two latching arms 72 also extend (see the indicated radius r in FIG. 12 ). The radius r approximately corresponds to the radius on which the locking lugs 40 lie.
[0066] The outer edges of the latching arms 72 facing away from each other are each provided with a guide contour 74 which is formed by guide surfaces 76 arranged in a V-shape (see FIG. 7 a ). The apexes of the two V-shaped guide contours 74 are rounded and the two apexes face each other. In other words: the guide contours 74 are formed as grooves along the outer edges of the latching arms 72 .
[0067] Designs other than the V-shape can also be used in the region of the contact between the latching arms 72 and the transmitter disk. Examples are shown in FIGS. 7 b to 7 e.
[0068] In FIG. 7 b , the edge of the transmitter disk 12 is concave on the side thereof facing the corresponding latching arm 72 , and specifically has a rectangular groove (as seen in cross-section). A complementarily convex outer edge of the corresponding latching arm 72 engages into said groove.
[0069] In FIG. 7 c , the edge of the transmitter disk 12 is likewise concave on the side thereof facing the corresponding latching arm 72 , and specifically is formed as a depression with a curved bottom (as seen in cross-section). A complementarily convex outer edge of the corresponding latching arm 72 engages into said depression.
[0070] In FIG. 7 d , the edge of the transmitter disk 12 is convex on the side thereof facing the corresponding latching arm 72 , and specifically has a rectangular protrusion (as seen in cross-section). Said protrusion is accommodated in a complementary groove having a rectangular cross-section in the outer edge of the corresponding latching arm 72 .
[0071] In FIG. 7 e , the edge of the transmitter disk 12 is likewise convex on the side thereof facing the corresponding latching arm 72 , and specifically is formed as a protrusion with a curved end face (as seen in cross-section). Said protrusion is accommodated in a complementary convex depression in the outer edge of the corresponding latching arm 72 .
[0072] Formed on each of the mutually facing inner edges of the latching arms 72 are two V-shaped sliding guide surfaces 78 (see in particular FIG. 11 ). The apex of the V-shaped contour is also rounded in this case and the apexes fie opposite one another. The two V-shaped contours on the inner side and outer side of the latching arms 72 are thus oriented in the same direction. However, the angles are different. Whilst the guide surfaces 76 together form an angle of less than 90°, the sliding guide surfaces 78 together form an angle of greater than 90° (likewise as measured on the “inner side” of the V-shaped contour). The crown angle for the guide contour 74 is in the order of magnitude of 60° whilst the crown angle for the sliding guide contour formed by the sliding guide surfaces 78 is in the order of magnitude of 120°.
[0073] The two latching arms 72 are each provided with a latching configuration 80 on their inner side on the free end, said configuration being in the form of a bead or protrusion (see in particular FIG. 12 ).
[0074] The base part 62 (see in particular FIGS. 9 and 14 to 17 ) comprises a planar bottom part 82 , from which two post-like protrusions 84 extend, which protrusions together form a spring bearing for the compression spring 64 . A circular depression 86 is provided in this case between the two protrusions 84 and is used to receive an and of the compression spring 64 . However, the depression is not absolutely necessary.
[0075] The two protrusions 84 are curved on their mutually facing inner sides, wherein the radius of curvature is adapted to the outer diameter of the compression spring 64 . The outer surfaces, facing away from each other, of the protrusions 84 are provided with sliding guide surfaces 88 which are inclined in the same manner as the sliding guide surfaces 78 on the guide part 60 . The sliding guide surfaces 78 of the guide part 60 form, together with the sliding guide surfaces 88 of the base part 62 , a sliding guide, along which the guide part 60 is guided and received thereon so as to be displaceable relative to the base part 62 .
[0076] Each of the sliding guide surfaces 88 of the protrusions 84 of the base part 62 is provided with a latching configuration 90 which likewise is in the form of a bead or protrusion. The latching configuration 90 is arranged, as seen starting from the bottom part 82 , in the order of magnitude of a third of the height of the protrusions 84 .
[0077] The smaller end faces, facing away from each other, of the bottom part 82 of the base part 62 are each formed as clip-in ends 92 . For this purpose, small, bead-like protrusions are provided on the end faces.
[0078] Each pressure piece 58 forms a pre-assembled unit (see FIG. 9 ). This unit consists of the base part 62 , the guide part 60 and the compression spring 64 .
[0079] In order to assemble a pressure piece, the compression spring 64 is inserted between the two protrusions 84 . Then, the guide part 60 is placed on the base part 62 such that the latching configurations 80 of the latching arms 72 latch behind the latching configurations 90 of the protrusions 84 (see the state in FIG. 9 ). In this state, the compression spring 64 is slightly biassed. However, it is not able to separate the guide part 60 from the base part 62 because its spring force is lower than the holding force of the form-fitting coupling of the latching configurations 80 and 90 .
[0080] The pressure pieces 58 are inserted into the recesses 46 of the transmitter disk 12 such that the guide surfaces 76 co-operate with the bevels 52 on the edges 50 of the recesses 46 (see in particular FIG. 7 ). The guide parts 60 are hereby accommodated in the recesses 46 so as to be displaceable in the radial direction, but are reliably held therein in the axial direction.
[0081] Insertion of the pressure pieces 58 into the recesses 46 is facilitated by insertion contours 53 which are attached to the edges 50 on the radially inner side (see in particular FIG. 6 ).
[0082] Upon assembly of the pressure pieces 58 in the recesses 46 of the transmitter disk 12 , the clip-in ends 92 of the base parts 62 engage into a suitably formed holding section 47 on the radially inner end of each recess 46 (see in particular FIG. 6 ). As a result, the pressure pieces 58 are pre-assembled in the transmitter disk 12 (see also FIG. 8 ).
[0083] If the synchronising rings 32 are mounted on the transmitter disk 12 , the pressure surfaces 56 of the pressure pieces 58 adjoin the two mutually facing centring bevels 54 of the locking lugs 40 (see FIGS. 4 and 6 ). Since the pressure surfaces 56 are curved in the circumferential direction, a line contact is produced.
[0084] When the transmitter disk 12 is mounted on the transmitter sleeve 22 , the base part 62 lies on the outer toothed arrangement 20 of the transmitter sleeve 22 (see FIG. 6 ) and therefore the base part 62 is supported in the radial direction. Therefore, if the guide part 60 is adjusted inwardly in the radial direction (in an interconnected position of the transmitter disk 12 ) and thus the compression spring 64 is biassed to a greater extent than in the initial state, the base part 62 also cannot be pushed inwards out of the holding section 47 .
[0085] The manner in which the clutch disks 14 are fastened to the side surfaces of the transmitter disk 12 will be described hereinafter with reference to FIGS. 18 to 22 .
[0086] The two clutch disks 14 are welded to the transmitter disk 12 , and in particular by projection welding (i.e. resistance welding at predetermined points).
[0087] Each clutch disk 14 is fastened to the transmitter disk 12 at four welding points 100 evenly spaced apart from each other in the circumferential direction. These are defined by material protrusions 102 which are produced alternately in opposite directions by plastic deformation of the material of the transmitter disk 12 , and in particular in a direction perpendicular to the plane which is defined by the transmitter disk (perpendicular to the plane of the drawing of FIG. 18 and in the direction of the arrow P in FIG. 19 ). A depression 104 is thereby formed on the side opposite the material protrusion 102 .
[0088] The material protrusions 102 which subsequently form the welding points 100 are formed on spacers 106 which are likewise formed by plastic deformation of the material of the transmitter disk 12 . The spacers 106 are produced in that the transmitter disk 12 is provided with an embossed portion 108 (see in particular FIG. 19 ) on the opposite side.
[0089] As can be seen in FIG. 18 , the spacers 106 and the embossed portions 108 are each arranged in pairs in the same sequence between adjacent recesses 46 for the pressure pieces 58 .
[0090] The spacer 106 ensures that a distance a is provided in each case between the transmitter disk 12 and the clutch disks 14 (see for example FIG. 22 ). The distance a allows a compression spring 64 to be used which has a diameter greater than the thickness of the transmitter disk 12 . A spring having a higher spring constant can hereby be used.
[0091] FIG. 19 illustrates the spacers 106 in a state in which the transmitter disk 12 is produced as a blank. The material protrusions 102 are provided in this state.
[0092] In order to connect the transmitter disk 12 to the two clutch disks 14 , these are arranged and oriented on the two side surfaces of the transmitter disk 12 . Then, they are fastened to one another by projection welding or resistance welding, wherein the material protrusions 102 melt on the spacers 106 so that the clutch disks 14 lie flat on the spacers 106 . This can be seen on the one hand in FIG. 22 and on the other hand in FIG. 20 in which the spacers 106 are shown without the material protrusions 102 . Welding points 100 remain in place of the material protrusions 102 , wherein the clutch disks 14 are materially bonded to the transmitter disk 12 at said welding points.
[0093] After the clutch disks 14 have been welded to the transmitter disk 12 , the thus formed assembly is hardened. This can occur in that the assembly is heated and then quickly cooled.
[0094] Depending upon the distortion due to hardening which is to be expected and can be tolerated, the assembly can either be freely hardened or even hardened on a mandrel, the outer contour of which corresponds precisely to the transmission shaft toothed arrangement 16 of the clutch disks 14 ; it is hereby ensured that the transmission shaft toothed arrangements 16 have a desired contour even after hardening.
[0095] After hardening, the pressure pieces 58 can be mounted in the recesses 46 where the base parts 62 latch into the holding sections 47 . | A transmitter for a synchronising assembly of a manual transmission has a transmitter disk and at least one clutch disk which is arranged on a side surface of the transmitter disk. The clutch disk and the transmitter disk are fixedly connected together by local welding points. A method for producing a transmitter for a synchronising assembly of a manual transmission consists of providing a clutch disk and a transmitter disk. Then, the clutch disk and the transmitter disk are fastened together by means of projection welding. Finally, the thus formed assembly is hardened. | 5 |
[0001] This invention relates to a sensor used to determine the relative position of two elements such as the stroke position of a hydraulic cylinder and to transmit the information to a control unit.
BACKGROUND OF THE INVENTION
[0002] The present invention is primarily concerned with detection of the relative positions of a piston and cylinder of a hydraulic or similar cylinder so that a value can be provided to a control system using the cylinder of the current location of the piston in the cylinder and thus the current location of an object controlled by that cylinder. However many of the principles disclosed herein can be used in detection of the distance between any two elements and the present application is therefore not limited to hydraulic cylinders.
[0003] The provision of a value representing displacement of a cylinder can be used in a system controlling the cylinder for many different end uses and purposes. One such purpose is for safety to ensure that the cylinder and theus the object is not moved to a specific location in dangerous circumstances such as when a door is open. Another such purpose is to provide interaction between different functions so that another element is controlled in dependence upon the specific location of a cylinder and thus the object, such as to maintain a bucket level as an arm is raised, for which function the location of the arm must be known.
[0004] The current technology used to measure hydraulic cylinder stroke position requires a hole be drilled the length of the cylinder shaft or the piston rod (gun drilling) and the sensor installed within. Repair, replacement or retrofit with this type of sensor is not practical as a serviced part. This arrangement is expensive and ineffective so that it has not yet met significant commercial success.
[0005] Some attempts have been made to use techniques using reflected sound waves and resonant frequencies but this technique is temperature dependent thus requiring temperature detection and compensation calculations so that the technique has not lead to any success.
[0006] In Published US Application 2002-0064300 of the present Assignees published May 30, 2002 there is described a method for detecting relative displacement between an object such as a slow moving vehicle and an illuminated surface which is normally the ground surface illuminated by an infrared light source so as to provide an output indicating the displacement or a velocity calculated from the displacement. The method includes providing an array of CCD or similar elements each arranged to receive light from a portion of a field of view and to provide an output responsive thereto. The method involves selection of a reference image and repeatedly comparing the reference image of the surface with each successive image by calculating the convolution integral of the signals using a fast Fourier transform to obtain a probable displacement value. The reference image is maintained as long as possible until a “Q” factor falls below an acceptable minimum, or until a predetermined time elapses or until a predetermined displacement is measured. The displacement values obtained from the comparisons can be filtered by discarding some values if they are outside an expected range of probable values.
SUMMARY OF THE INVENTION
[0007] It is one object of the invention to provide a sensor used to determine the relative position of two elements.
[0008] According to one aspect of the invention there is provided an apparatus for providing a signal indicative of a distance from a first element to a second element comprising:
[0009] a housing for attachment to the second element;
[0010] an optical imager carried on the housing that is fixed on the second element with the optical imager pointed to the first element;
[0011] an image processor for receiving an image signal of acquired images from the optical imager;
[0012] the image processor being arranged to identify image components on the first element from the acquired images of the first element, to determine the image dimensions of the image components and to calculate from the image dimensions the distance between the elements; and
[0013] a communication element that reports the calculated distance to a system controller.
[0014] According to a second aspect of the invention there is provided a combination comprising:
[0015] a cylinder having an end wall;
[0016] a piston mounted within the cylinder for longitudinal movement therealong so as to change the distance of an end face of the piston from the end wall of the cylinder;
[0017] and an apparatus for providing a signal indicative of a distance from the end face of the cylinder to the end face of the piston comprising:
[0018] a housing arranged to be mounted at the cylinder;
[0019] an optical imager fixed on the end wall of the cylinder with the optical imager pointed to the end face of the piston;
[0020] an image processor for receiving an image signal of acquired images from the optical imager;
[0021] the image processor being arranged to identify image components on the end face of the piston from the acquired images of the end face of the piston, to determine the image dimensions of the image components and to calculate from the image dimensions the distance between the end face of the piston and the end wall of the cylinder; and
[0022] a communication element that reports the calculated distance to a system controller.
[0023] The following optional features are particularly applicable to the arrangement where the device is used for a cylinder and piston combination but can be used in other situations as required.
[0024] Preferably the apparatus includes a light source arranged to be mounted on the end wall of the cylinder that is aligned with the imager and illuminates the end face of the piston. The light source is required in situations where the first element is insufficiently illuminated such as in the interior of the cylinder but also in many other enclosed situations where the natural illumination is obscured or absent.
[0025] Preferably all components are assembled into a single structure at the housing so that a single housing can be mounted on the second element. However the individual components may be separately housed. Parts of the system may be located on the second element or remote from the second element.
[0026] In a particularly convenient arrangement for use particularly with the cylinder and piston, but also usable in any situation where the housing is to be mounted on an end plate, there is provided a light pipe arranged to extend through a hole in the end wall to deliver images of the end face to the imager.
[0027] Where it is not suitable for illumination and the image to pass through a single light pipe common to both there can be provided a first light pipe arranged to extend through a first hole in the end wall to deliver illumination from a light source outside the hole to the end face and a second light pipe arranged to extend through a second hole in the end wall to deliver images of the end face to the imager outside the hole.
[0028] Preferably the image processor is arranged to analyze the acquired image and determine therefrom at least one visible component on the end face that is suitable for distance calculation.
[0029] Preferably the light source is arranged to increase light intensity as the distance of the end face from the end wall increases to maintain at least a minimum acceptable illumination.
[0030] Preferably the light source communicates the light therefrom through a light pipe and wherein the light pipe is arranged with an end surface defining an area which is generally illuminated to avoid point source illumination, thus reducing reflections and bright spots on the image.
[0031] Preferably there is provided an input for calibration data wherein the calibration data relates either to actual measurements of distances of the piston relative to the cylinder or to parameters such as diameter or length or manufacturers identifying information of the piston and cylinder.
[0032] Preferably the image processor is arranged in a first process to cancel bright spots on the image.
[0033] Preferably the image processor is arranged to select from the image a characteristic part of the image of the end face, that is a component on the end face which has a characteristic shape which can be readily distinguished from other shapes. This may be in the example of the piston head, the end nut which has the characteristic hexagon shape allowing its location to be accurately determined from at least a side and two angles.
[0034] Preferably the image processor is arranged to use the selected characteristic part to locate a specific component, such as the circular end face of the piston, having a predetermined characteristic dimension of the second element. That is the dimension of the characteristic part has a predetermined well known and fixed dimension which can be compared on the image to determine its distance.
[0035] Preferably, having determined the location on the image of the characteristic part, the image processor is arranged to determine the image dimensions of the image components by determining the area of the characteristic part, that is in the example concerned the end face of the piston, on the image.
[0036] Preferably the image processor is arranged to determine the image dimensions of the image components by determining the number of pixels of the image thereof within a boundary thereof, that is a sum which is directly proportional to the area. This counting of pixels in an area reduces the errors possible if only a single dimension were calculated.
[0037] In some cases where the whole of the area of interest is not on the image, the image processor is arranged to determine the number of pixels by extrapolating to include areas of the components which are outside the field of view.
[0038] Preferably the apparatus is arranged such that the end face of the piston is a matt surface to reduce bright spots from reflections.
[0039] In some cases it is desirable to provide additional markings on the end face to provide characteristics which are readily discernible on the image. This may be necessary where the element concerned has no distinguishing features which allow the area of interest to be readily determined or if the piston is too close to the end wall for the imager to discern visible components of the end face
[0040] Conveniently the markings may be concentric circles with a characteristic spacing which allows them to be readily distinguished and their area to be determined by the above technique.
[0041] Preferably the image processor is arranged to select different components on the end face as the areas of interest depending upon the distance of the end face from the end wall.
[0042] The arrangement described herein thus provides an optical sensor array will be used to capture an image of the piston features (piston face) (blank end), (rod nut and rod end). Using image-processing techniques, the image size of the piston features can be determined and compared with their physical dimensions. The piston distance from the optical sensor will be calculated from the comparison and transmitted to the control unit.
[0043] The sensor is installed from the outside of the cylinder, through a threaded hole in the blank end of the cylinder. The sensor installation will not require extensive cylinder modifications. The sensor will be field replaceable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
[0045] FIG. 1 is an exploded view showing an end cap of a cylinder including a distance measurement sensor according to the present invention mounted thereon.
[0046] FIG. 2 is a cross sectional view of the cylinder head of FIG. 1 .
[0047] FIG. 3 is a schematic cross sectional view showing the mode of operation of the sensor of FIG. 1 .
[0048] FIG. 4 is an end elevational view of an end face of the piston rod showing a series of images of the end face for analysis.
[0049] FIG. 5 is a schematic illustration of the combination according to the present invention.
[0050] In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
[0051] The distance measuring device disclosed herein is primarily intended for measuring in real time the relative locations of a cylinder head 10 of a cylinder 11 and a piston 12 within the cylinder 11 . This measurement provides a specific distance between the cylinder head and the piston so as to be able to provide to control equipment a specific location of the piston within the cylinder allowing accurate control of the cylinder.
[0052] The distance measuring device comprises a measuring apparatus 13 mounted on the cylinder head for detecting the distance from a front face 14 of the piston 12 . Thus the cylinder head 10 forms one element and the front face 14 forms a second element so that the distance therebetween is measured. It will be appreciated that, while the arrangement disclosed herein is primarily concerned with cylinders and the piston mounted therein, it can be used in any other field where two elements move relative to one another along a predetermined axis so as to increase and decrease the spacing therebetween.
[0053] The apparatus is shown in more detail in FIGS. 1 and 2 where the cylinder head 10 is shown in more detail and includes an end face 15 outside the cylinder and an end face 16 within the cylinder and closing the end of the cylinder. Through the end cap 10 is provided a bore 17 which defines a mounting for the end of the cylinder for attachment to a pivot pin in conventional manner.
[0054] A bore 18 is formed through the end cap 10 at a position offset from a center of the end cap so as to pass through the end cap to one side of the bore 17 . And end face 19 of the bore 18 breaks out on the surface 16 . A counter bore 20 of larger diameter is formed co-axial with the bore 18 at the surface 15 . A bore 21 is formed at the center of the end cap and breaks out on the surface 15 and at the bore 17 . The end cap 10 thus forms a modified end cap which is manufactured with the above elements and is used in replacement for a conventional end cap on a conventional cylinder and fastened to the end of the cylinder in a conventional manner.
[0055] The distance measuring device comprises a mounting body 25 which is arranged to be clamped onto the end face 15 of the end cap. The body includes a threaded opening 26 by which it can be fastened to the bore 21 by a threaded fastener which passes through the opening 26 and into the bore 21 to provide a threaded coupling holding the housing on the end cap. The housing has a flat bottom surface which sits against the end face 15 and is shaped so that it provides a thin body covering a part of the surface 15 and particularly over the bore 20 . The enclosure receives a printed circuit board 27 which is shaped so as to match into the interior of the housing and sit within the interior contained within side walls of the housing and enclosed by suitable enclosure of the housing as is well known to one skilled in the art.
[0056] The measuring device further includes a light pipe 28 which is formed of a suitable transparent plastics material which extends into and fills the bores 18 and 20 . Thus the light pipe includes a cylindrical portion 29 and a cap portion 30 generally matching the dimensions of the bores 18 and 20 . Thus particularly the cylindrical portion 29 has the same diameter as the bore 18 so it is a sliding fit within the bore 18 and has an end face 31 which is circular and located at the bottom surface 16 of the end cap. The cap 30 is slightly shallower than the bore 20 but has an outside diameter matching the bore 20 . The end cap thus defines a shoulder 32 for engaging against a shoulder 20 A at the end of the bore 20 . A sealing ring 33 is provided which is located between the shoulder 32 and the shoulder 20 A so as to seal the light pipe in place within the bore and prevent the escape of fluid from within the interior of the cylinder through the bore 18 .
[0057] The light pipe is held in place by a retaining washer 34 and a threaded retaining ring 35 which threads into a female threaded surface on the bore 20 and clamps the cap 30 of the light pipe down into the bore 20 so as to squeeze the sealing ring 33 .
[0058] The PCB 27 carries the components as described in more detail herein after including particularly an optical imager 36 and one or more light emitting diodes (LED) 37 which are carried on the underside of the PCB and communicate with a clear window 38 on the upper side of the light pipe 28 thus allowing communication of light from the LED downwardly through the light pipe into the cylinder and reflected light upwardly through the light pipe to the image receiver 36 .
[0059] Thus in the embodiment shown a single light pipe provides communication of light in both directions including illuminating light from the LEDs and reflected light to the imager. However in some embodiments two separate light pipes can be provided each extending through its own individual bore, depending upon geometry and illumination levels.
[0060] In the embodiment with two separate light pipes the illuminating pipe is made of translucent material so that it forms at its end face not a point image of the LED but instead a generalized circular illumination covering the end face of the light pipe. This reduces bright spots in reflected light within the cylinder.
[0061] Turning now to FIG. 5 , the above components are shown schematically together with a processor 40 which controls the operation of the LED and the optical imager in response to program 41 contained within a memory module of the processor. The processor communicates through a communication interface 42 with exterior components as indicated at 43 so that the data obtained in the processor from the operation of the program can be communicated to external components for operating control of the cylinder. The device operates by the use of the optical imager and the program to analyze the reflected light from the first element which is the end face 14 of the piston to provide an acquired image of the end face 14 and from that image to determine certain image dimensions of the components of that image and to calculate from the image dimensions the distance between the optical imager and the end face 13 and therefore between the end cap 10 and the piston 12 .
[0062] It will be appreciated in general that the distance between the optical imager and the end face 14 is inversely proportional to the dimensions of components of the image on the optical imager. Thus it is necessary to analyze the image of the end face 14 forming the first element and to acquire a numerical value indicative of the dimensions of those image components to provide a numerical value which is inversely proportional to the distance as shown in FIG. 4 there is illustrated an end face of the piston which includes a peripheral edge 12 A, a central circular end face 12 B of the piston rod, a hexagonal nut 12 C holding the piston onto the end of the rod 12 B and markings 12 D provided on the end face of the piston. The physical dimensions of all of these components and the dimensions of images of these components acquired by image processing can be used to calculate the distance of the end face 14 of the piston relative to the optical image.
[0063] Depending upon the distance of the piston from the optical imager, the whole end face 14 or different amounts of it are visible within the view of the optical imager. Thus in FIG. 4 , 3 views are illustrated in dash line at 50 , 51 and 52 depending upon the distance of the piston from the optical imager. It will of course be appreciated that when the piston is very close, only a small part such as indicated at 52 of the end face is visible within the range of the optical imager, bearing in mind the dimensions of the light pipe. This view increases as the piston moves away so that when it is a significant distance away, enough of the piston is visible so that the outside edge 12 A can be readily determined within the image. Thus as shown for example in the image 50 , a portion of the peripheral surface 12 A between points 12 E and 12 F can be determined which is readily determinable from the image in view of the fact that it forms a smooth circular shape. The whole of the end face is not within the image since the image is offset relative to the circular peripheral edge 12 A. It will be appreciated that the diameter of the image of the peripheral edge 12 A is inversely proportional to the distance from the optical imager.
[0064] This diameter is determined by firstly analyzing the area of the end face within the peripheral edge 12 A which lies within the image 50 . This is determined by counting the number of pixels on the image which are within the circular edge 12 A between the points 12 E and 12 F. The program then carries out an extrapolation from the points 12 E and 12 F to determine the full area of the end face as it would appear if it were wholly within the image. This area is proportional to the diameter which can thus be readily calculated and thus proportional to the distance of the end face from the imager.
[0065] Thus when the piston is sufficiently distanced from the end cap of the cylinder, the analysis is carried out by determining the position of the peripheral edge which can be readily viewed since it is sufficiently clear as a circular image or its part to determine the exact location of the peripheral edge.
[0066] However as the piston moves closer to the end cap, the amount of the peripheral edge 12 A which is visible becomes decreased so it becomes more difficult to determine from the image exactly which line forms the peripheral edge 12 A and what are the exact bounds of this edge. It is necessary therefore to utilize similar technique in order to identify other components of the image. This analysis therefore is carried out using the peripheral edge 12 G of the nut 12 C and particular the apexes 12 H and 12 J which are particularly distinct within the image 51 . Each apex has a particular angle and is defined by two lines at that angle so that the nut image area can be specifically and accurately determined.
[0067] From this area and the physical nut area the distance of the end face from the optical imager can be calculated.
[0068] In the event that the piston has moved to a position so that the nut also no longer falls within the image as indicated at 52 , a further technique is used to determine dimensions of components on the end face 14 . In this technique, additional markings 12 D are provided on the end face in the form of two or more concentric circles indicated at 12 D. These concentric circles are therefore readily visible within the image and can readily determined from other extraneous elements or components within the image. Having determined the location of the markings 12 D, area between the circles on the image can be determined by counting the number of pixels that fall between them. A ratio of areas between the circles in the image can be compared with the physical dimensions of the circles and used to calculate to the distance of the end face from the optical imager. Thus when none of the elements of the end face are visible within the image, additional markings are provided so as to provide visible elements on the end face which can be analysed on the image and their dimensions or area determined.
[0069] The program is thus arranged to analyze the image looking for each of the elements of the image in turn to determine which of those elements should be used for the analysis of the diameter or dimension of the particular component concerned.
[0070] The end face 14 is preferably rendered matt by sanding or other surface characteristics so as to reduce direct reflections thus reducing bright spots on the image. However reflections occur on the inside surface of the cylinder and on various surfaces at an angle to the end face so that the image viewed contains many bright spots and many reflected shapes thus requiring careful analysis of the image to determine the component which is to be used. Reflections are minimized as much as possible by the use of matt surfaces. Bright spots are cancelled in the processing of the image from the program by initially analyzing the image for those bright spots and using known program characteristics to eliminate initially the bright spots before analysing the image for the components to be determined.
[0071] In order to ensure sufficient intensity of the image, the program is arranged to control the current supply to the LED so as to increase or decrease the amount of illumination sufficiently to observe the components of the image. Thus the LED initially is excited to a predetermined value and the intensity of illumination is increased in the event that the program fails to determine any image components for analysis. In the event that, after increase of the illumination to the maximum value, no image components can still be determined, the program is arranged to communicate from the processor through the communication interface a fault signal.
[0072] In the analysis of the distance of the piston from the cylinder head, the circular shape of the piston is particularly characteristic and readily visible when the piston is within a certain range. Only when the piston approaches too close to the end cap it is necessary for additional processing arrangements to be utilized. However in other distance measuring devices which are not used with a cylinder, other components may be used on the first element as the element to be analysed. Such elements may not include such a readily visually distinct component such as the circular peripheral face or the nut and thus markings such as the markings 12 D may be used as the primary analysis tool.
[0073] Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the Claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense. | A signal indicative of a distance from a first element to a second element, such as the end face of a piston from the end wall of its cylinder, is generated by providing an optical imager carried on a housing that is fixed on the end wall with the optical imager pointed to the end face. An image processor is arranged to identify image components, such as the end nut on the piston, from the acquired images of the first element. From the location of the nut the processor can identify the location of the outer edge of the circular end face and can determine the area of the end face in the image by counting pixels within the area. From the measured area as it appears in the image the distance can be calculated. The end face is illuminated by a light source shining through a light pipe passing through a drilled hole in the end wall. Characteristic markings can be applied on the end face for measuring distance when the nut is too close to be visible. | 6 |
This is a continuation of application Ser. No. 7,211 filed Jan. 29, 1979, now abandoned, which is a continuation of application Ser. No. 810,267, filed June 27, 1977, now abandoned.
FIELD OF THE INVENTION
The present invention relates to an elongated form box or mold which has at least two parts which can be released from one another and which are separated by longitudinal joints and in which mounting means for the reinforcing preform are arranged.
BACKGROUND OF THE INVENTION
The manufacture of polyurethane profiles in pregiven usable lengths as they are needed for the articles, for example windows, which are to be manufactured individually, is known.
The manufacture of profiles with pregiven usable lengths and which contain a perforated steel pipe so that the polyurethane mass which surrounds the steel pipe fills out also the inside of the pipe is known. The steel pipe lies back on the two front sides of the profile. The profiles are connected at the ends, which ends have a beveled construction, by means of metal corner angles which are pressed with a large force into preformed recesses within the plastic.
In addition, the manufacture of profiles with pregiven usable lengths is known, the core of which consists of wood or an aluminum profile and the outside of which consists also of a polyurethane mass. Both reinforcing profiles spring back at the ends. The corner connection is done by threading a screw into a nut which is cast into the counter profile or by the corner angle connections.
In addition, it is known to produce a window in one piece. For this a separate form is needed for each window size and frame type and still not all areas of dimension can be included. The manufacture is very expensive, the system has little capability for adjustment.
The manufacture of individual usable lengths of profiles in contrast to long profiles, which can be separated as needed and can then be connected, is proven to be of a great disadvantage. Because of the many window sizes the manufacture of individual usable lengths means a great number of different profile lengths, which results in a large expense in the preparation for manufacture, to carry same out and to deliver the product. Up to now it was not possible to manufacture profiles of the abovementioned type in large lengths.
The basic purpose of the present invention is to develop a profile and a mold for forming the profile by coating a preform with plastic. Thus the purpose consists in the development of long plastic profiles, in particular window profiles, made preferably of polyurethane and having an integrated reinforcing preform which permit through severing at any desired location a variable window design with a high quality corner connection.
The invention includes the provision of a mold in which the reinforcing preforms are precisely aligned on the form wall with lengths of approximately 5,000-6,000 mm.
Problems can arise in the manufacture of profiles in forms or molds without taking any special measures especially in situations where the profiles have a greater length than approximately the provided usable length, because in the case of longer profiles the reinforcing preform does not extend exactly straight between its support points at the form ends but is, instead, bent more or less in a vertical and/or a horizontal plane. In particular, the weight of the reinforcing preform causes a downward sag. In the case of the existing manufacture of common usable lengths, deviations from the straight form were not annoying in each case because these deviations were not excessively great due to the relatively small distance between the end supports and due to a precise positioning in the end areas. As a result, the connection of the profiles to, for example, window frames by means of corner angles did not bring with it any special difficulties.
If, however, longer profile rods are manufactured, which by a cutting of suitable pieces to a usable length, it is necessary that the reinforcing preforms have over their entire length exactly the same position relative to the outer shape of the profile. Only then will the correct alignment of the reinforcing preform with respect to the outer shape exist. This alignment is a condition for a good corner connection by means of corner angles. Also one would risk, by a fixing of a very long reinforcing preform only at its ends such great deviations from the correct position, that the spacing of the reinforcing preform walls from the outer wall of the profile becomes too small and it may even happen that the reinforcing preform becomes visible. However, in the situation of small shiftings of the reinforcing preform considerable disadvantages will occur, like streak formations and color differences on the plastic surface and an influence on the heat insulation characteristic.
The inventive form of the abovementioned type is characterized by arranging pins which are rigidly connected to the form box or mold between the ends of the form box at at least one point (fixing point), preferably at several fixing points and engage the reinforcing preform and hold same over its entire length at an even distance from the inside walls of the form box.
Such a form permits also to fix exactly very long reinforcing preforms relative to the inside wall of the form, so that it is assured that at each later cutting or severing location, the reinforcing preform lies exactly correctly relative to the outer wall of the form. Thus it is possible to manufacture the profiles in lengths of approximately 5,000 to 6,000 mm. Experience has shown, that an arrangement of fixing points at intervals of approximately 800 mm. is sufficient.
If the pins are moved not before the plastic is hardened, holes will remain in the profile and are formed from the pins. It is therefore of an advantage to permit the pins to project from such walls of the form box and form surfaces on the profile, which surfaces will not be visible after installation.
Various pin arrangements are possible. Particularly important are pins provided for the purpose of supporting the reinforcing preform against a downward sag. The preform can, however, also experience a considerable hydrostatic lift or pressure through an expanding foam mass which would effect an upward bending. Action can be taken against this with an arrangement wherein an upper set of pins engage and maintain the upper surface of the preform fixed relative to the lower part of the form box. A pin arrangement wherein the upper pin is equidistantly spaced from a pair of laterally spaced lower pins brings about in the simplest manner a securing of the preform against lateral tilting or warping.
Particular advantages are obtained if according to a further development of the invention the reinforcing preform receives a special construction. In particular the fitting edges are of an advantage, because they cause for example the pins to engage only the bottom of the reinforcing preform while at the same time effecting a lateral fixing of the same. The arrangement of more than two fitting edges (i.e. shoulders) has the advantage that the same reinforcing preforms can be used for different profile forms, because a lateral fixing with the aid of the fitting edges makes it possible for different preform to be fixed in position by fixing pins arranged at such points on the form which do not form later visible sides of the profile.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the invention are illustrated in the drawings, in which:
FIG. 1 is a longitudinal cross-sectional view of an inventive form or mold:
FIG. 2 is a cross-sectional view taken along the line II--II of FIG. 1 or a scale which is enlarged with respect to FIG. 1;
FIG. 3 is a cross-sectional view of a reinforcing preform according to a different embodiment of the invention;
FIG. 4 is an enlarged section of the area in FIG. 3 that is encircled by the dash-dotted circle IV;
FIG. 5 is a modification of the reinforcing preform; and
FIG. 6 is a perspective illustration of a profile.
DETAILED DESCRIPTION
FIG. 1 illustrates a form or mold which as a whole is identified by the reference numeral 1 and is shown in its natural position, as it is chosen for forms, which are foamed with plastic, namely the form extends slightly inclined wherein the angle of slope α, for example, is in the range of approximately 6° to 15°. The form is substantially an elongated box or mold, the cross section of which is enlarged in FIG. 2. The form box or mold 1 has a lower part which as a whole is identified by the reference numeral 2 and an upper part which as a whole is identified by the reference numeral 3. The upper part 3 can be released from engagement with the lower part 2 along joints 4 and 5 which extend along the length of the entire form. End walls 6 and 7 are mounted on the ends of the form box 1. Tongues 8 and 9 project from the end walls 6 and 7, respectively, to which tongues a reinforcing preform 10 can be fixed at its ends.
The form box or mold has a cavity 11, the walls 12 of which form the sidewalls of a profile. A mold for the manufacture of a window profile is illustrated.
The reinforcing preform 10 which is illustrated in FIG. 2 is box-shaped in construction. The preform 10 has a cavity 13, which is defined by walls 10a to 10d. The walls 10a, 10b and 10d are planar in construction, while the wall 10c has a notch 14 therein defined laterally by fitting edges or shoulders 15 and 16. The wall 10d has extensions 17 and 18 which project outwardly beyond the walls 10a and 10c, the edges of which extensions have notches therein. The tabs 17a, 17b and 18a, 18b are alternately bent out from the plane of the wall extensions 17,18 and form anchorage projections.
So-called fixing points are inventively arranged along the form or mold at several points, which fixing points have been identified in FIG. 1 together by the reference numeral 19. The fixing points are distributed evenly over the length of the form and are spaced from one another at a distance "a", which can be for example 800 mm. The distance "a" depends also on the respective form or mold of the reinforcing profile which is to be fixed. In the case of a particularly unstable reinforcing preform, the distance "a" must be smaller than is necessary in the case of a particularly stiff preform. The fixing points are constructed in the illustrated embodiment in the manner as is shown in FIG. 2.
Pins 20 and 21 are provided at each fixing point in the bottom 2a of the form box part 2, which pins 20 and 21 are spaced from one another in a direction transversely to the longitudinal direction of the form box or mold. A further fixing pin 22 is provided in the bottom 3a of the upper form box part 3, which fixing pin 22 lies between the pins 20 and 21. The pins 20,21 are conically constructed adjacent their upper end 20a or 21a (FIG. 3) and are tapered upwardly. The upper fixing pin 22 is also tapered. Each fixing pin has an approximately planar or flat end surface.
In the illustrated embodiment, the fixing pins are pressed into blind holes in the form wall or are secured by a thread.
During the manufacture of a profile, the reinforcing preform 10 is inserted into the form box 1 when the upper form box part 3a is still lifted off and the tongues 8,9 are moved into the cavity 13. The conical ends 20a,21a of the fixing pins 20,21 will rest with their conical side surfaces against the fitting edges or shoulders 15,16. The base 14a of the recess 14 rests on the top surfaces of the fixing pins 20,21. When the upper form box part 3a is mounted on top of the form box part 2, the lower surface on the upper fixing pin 22 presses on the wall 10a and thus causes a fixed engagement of the fixing pins 20,21 with the base 14a of the recess 41. Because of the engagement with the edges 15,16, the pins 20,21 are also able to fix the reinforcing preform 10 against displacement toward the side relative to the form box. As a result, it is assured that the outer walls of the reinforcing preform have over the entire length thereof the same spacing from the inner walls 12 of the form box. Due to the conically-shaped end zones 20a,21a of the lower fixing pins it is also possible to achieve precise lateral fit (seat). The upper part of the form 3 is precisely fixed relative to the lower part of the form 2. The form is then held in the closing position by not shown means. The plastic foam mass is filled in thereafter through the feedhead 23 (FIG. 1), namely substantially at the lowermost point of the form 1, through which due to a subsequent reaction and expansion, the form cavity 11 is filled in. A hydrostatic lift or a change of the position of the reinforcing preform 10 in the form part, for example, cannot take place because this is prevented by the fixing pins.
After hardening of the plastic, the form is opened and the fixing pins 20,21 and 22 are simultaneously pulled out of the plastic. Openings remain then in the plastic. This, however, is not of any disadvantage because the openings are at locations on the finished profile which are not visible in the position of use thereof.
If the operation takes place when the plastic is still flowable, the pins can still be pulled back and are pulled back when the plastic has hardened such that a shifting of the reinforcing preform 10 must no longer be feared; however, the plastic still has the capability of filling in the recesses left by the pins.
In a preferred modification of manufacture, an adhesive is applied to the outside of the reinforcing preform 10, the composition of which depends on the material of the reinforcing preform and of the plastic material and has the characteristic of producing a good connection between the reinforcing preform and the plastic. Alternatively and additionally, the anchorage projections 17a,17b and 18a,18b and possible further anchorage projections which are not shown assure that a shifting between the plastic and the reinforcing preform 10 does not take place.
During processing of the profiles which are manufactured in large lengths (the length L of the form 1 being for example 6,000 mm.), suitable pieces are manufactured by severing the length into several sections and the angle of severing is done as a rule at an angle of 45°. The reinforcing preform 10 is also severed.
FIG. 3 shows a reinforcing preform 10' which has two riblike elevations 25 and 26, the inner sides of which form fitting edges 25a and 26a. As one can see from the enlarged section in FIG. 4, each fitting edge has surfaces 27 and 28 and the sloped surface 28 presents an introducing slope, while the surface 27 is the actual fixing surface or shoulder.
The fixing pins 20,21 and 22 are indicated by dash-dotted lines in FIG. 3. Both the introducing slopes 28 and also the conical ends 20a,21a of the lower fixing pins ease the engagement of the fixing pins with the fitting edges 27.
FIG. 5 illustrates a further modification 10" in which additionally to the ribs 25 and 26 a rib 29 is provided. The ribs 26 and 29 are identically oriented, namely their fitting edges 26a and 29a both face to the left. The additional fitting edge 29a according to FIG. 5 makes it possible to laterally fix the reinforcing preform selectively between the fitting edges 25a and 29a or between the fitting edges 25a and 26a. The distance between the ribs 29 and 26 must be at least sufficient that the engaging end of the fixing pin 21 fits between the ribs 26 and 29. The selective fixing possibility has the advantage that the same reinforcing preform can be used for the manufacture of different profiles and the possibility of selections for the place of engagement of the fixing pins opens up the possibility of avoiding later visible surfaces on the profile which was in engagement with the fixing pins.
The looks of a profile can be taken entirely from FIG. 2, for which reason a separate profile drawing would actually not be necessary. Nevertheless FIG. 6 illustrates perspectively a profile piece. The profile is identified as a whole by the reference numeral 30 and has the cross-sectional shape which is visible from FIG. 2, which shape is defined by the cross section of the form. Holes 31 are visible on the finished profile. However, FIG. 6 shows only the holes which are formed by the upper fixing pins 22, while the holes which are formed by the lower fixing pins 20,21 cannot be seen.
Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | A form box for manufacturing a form, which form box is adapted to hold a reinforcing preform in position during the period of time that an expanding foam mass is injected into the area between the reinforcing preform and the form box. Pins are secured to the form box and project inwardly into the form cavity in which is located the reinforcing preform. The free ends of the pins engage the reinforcing preform to hold same in a fixed position during the period of time that the expanding foam mass is injected into the cavity between the reinforcing preform and the form box. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
Broadly the invention relates to rope pulling devices. More specifically, it concerns devices that a person may hold in a hand to grasp a rope to assist in rapid, forceful pulling of the rope.
2. Description of the Prior Art
Numerous devices exist to help pull ropes, cables or other lines. These vary from simple, hand-held items to more complicated equipment such as winches and windlass machines. This invention concerns improvements in the simple, hand-held type of rope puller.
It is frequently necessary to rapidly pull a length of rope through a sheave or the like to move a weight or other item attached to the other end of the rope. Usually the task requires that strong tension be applied to the rope and also that the rope move rapidly. A primative way for increasing tension in the hand pulling of a rope is to wrap the rope around a hand, pull the rope a short distance, unwrap the rope to move the hand forward on the rope, rewrap and repull and repeat this until the required length of rope has been pulled. The wrapping and unwrapping slows down the operation and can bruise the puller's hand. This invention concerns rope pullers that permit maximum tension to be applied to the rope while increasing the speed with which the rope is pulled.
The rope pullers of the invention include a wedge section that grasps a rope inserted therein. It is known in the art to use wedge members to grasp or cleat ropes, e.g., see U.S. Pat. No. 3,956,785.
OBJECTS
A principal object of this invention is the provision of improvements in hand pullers for ropes.
A further object is the provision of simple, hand-held rope pullers that enable a person to pull a rope at relatively high speed and with substantially greater tension than would be possible with bare hands.
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 while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
SUMMARY OF THE INVENTION
These objects are accomplished according to the present invention by providing a rope pulling device comprising a handle portion and a rope cleating portion attached to the handle portion. The cleating portion comprises a wedge section that will tightly grasp a rope inserted therein when the device is moved to tension the rope, but allows the rope to be easily released when the device is moved to release tension on the rope.
Preferably, the handle portion of the rope puller comprises a bar and a pair of parallel, spaced-apart strips integral with and perpendicular to the bar.
The wedge section of the rope cleating portion may be formed in a variety of ways. In one form, it comprises a triangular slot in a web member that bridges the strips of the handle portion. In another form, it comprises a pair of tapered lugs that provide a V-shaped opening in which the rope is cleated.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be had by reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a rope puller of the invention showing in phantom line how the puller is used.
FIG. 2 is an anterior view of the puller of FIG. 1.
FIG. 3 is a posterior view of the puller of FIG. 1.
FIG. 4 is a lateral view of the puller of FIG. 1.
FIG. 5 is a sectional view taken on the line 5--5 of FIG. 2.
FIG. 6 is a sectional view taken on the line 6--6 of FIG. 4.
FIG. 7 is a sectional view taken on the line 7--7 of FIG. 4.
FIG. 8 is an isometric view of another embodiment of a rope puller of the invention.
FIG. 9 is an anterior view of the puller of FIG. 8.
FIG. 10 is a posterior view of the puller of FIG. 8.
FIG. 11 is a lateral view of the puller of FIG. 8.
FIG. 12 is a sectional view taken on the line 12--12 of FIG. 9.
FIG. 13 is an end view of the puller of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in detail to the drawings, the rope pulling device 2 comprises a handle portion 4 and a rope cleating portion 6 which has a wedge section 8 to grasp a rope 9 inserted therein.
The handle portion 4 consists of a bar 10 and a pair of parallel, spaced-apart strips 12 integral with and perpendicular to the bar 10. In order to reduce the mass of the bar 10 without harming its strength, the bar is formed such as by injection molding of high strength plastic, with recesses or hollows 14 and cross-ribs 16.
The rope cleating portion 6 comprises a triangular base section 18, a pair of right-angled triangular sides 20 integral with the base 18 along the hypotenuse 22. A triangular web 24 extends between and integral with the upper pair of legs 26 of the sides 20. A trapezoidal web 28 extends between and integral with the other pair of legs 30 of the sides 20.
A triangular slot 32 is formed in the web 24 with its apex 34 distal to the handle 4. There is an arcuate opening 36 in the web 28 that joins to the slot 32 at its base 38.
The method of use of the rope puller 2 is illustrated by FIG. 1. The handle portion 4 is grasped in the hand 40 of the user and rope 10 is inserted into the slot 32 of the cleating portion 6. When tension is applied to the rope by pulling in the direction indicated by the arrow in FIG. 1, the wedge section 8 serves to grasp or cleat the rope enabling the user to pull the rope to the full extent possible with the users arm. At this point, the other hand of the user (not shown) is used to grasp the rope and hold it at a steady position. The rope puller 2 is then moved in the opposite direction to the arrow in FIG. 1 thereby relieving tension applied to the rope by the rope puller 2. This permits the rope 9 to be released by the wedge section 8, whereupon the puller 2 may be advanced further along the rope 9. The rope at the advanced point is then reinserted in the wedge section 8 and the pulling, stop, release and reposition operation is repeated until the desired length of rope has been moved.
Instead of using the puller 2 to move a long length of rope through a sheave, or the like, the puller 2 may be used to tighten short lengths of rope, e.g., lacing extending between pieces of canvass, etc.
The embodiment of the rope puller 2A shown in FIGS. 8-13 has the same basic features as the puller of FIG. 1, namely, a handle portion 4, and a rope cleating portion 6A which has a wedge section 8A.
The handle portion 4 with strips 12 is substantially identical to the puller 2 of FIG. 1. The difference is in the wedge section 8A.
The rope cleating portion 6A comprises a longitudinal base section 42 and a pair of space-apart lugs 44 extending perpendicular from one surface 46 of the base section 42. The inside surfaces 48 of the lugs 44 taper outwardly from the base section 42 forming a V-shaped wedge section 8A. The inside surfaces 48 have a series of parallel serrations 50 therein that extend at an acute angle relative to the base section 42.
The method of use of the rope puller 2A is comparable to that described for rope puller 2. In use, a rope (not shown in FIG. 8) will be intermittently grasped or cleated by the wedge section 8A to tension and/or advance the rope. Such operation can be accomplished quickly without damage to the hands of the user of the puller and with much greater tension being applied to the rope than is possible with bare hands. | A device to assist in the hand pulling of ropes comprises a handle portion and a rope cleating portion attached to the handle portion and having a wedge section to grasp a rope inserted therein. | 5 |
This is a continuation-in-part of application Ser. No. 820,472, filed Jan. 17, 1986, now abandoned.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to the treatment of nonacne inflammatory dermatoses, infectious cutaneous diseases, and hair loss resulting from inflammation or hormonal anomalies. In particular, this invention is directed toward conditions involving inflammation or infection of the adnexa, dermis and epidermis or hormonal involution of hair follicles including such dermatoses as rosacea, perioral dermatitis, eczema, seborrheic dermatitis, psoriasis, tinea cruris, flat warts, alopecia areata, male pattern baldness and similar conditions.
The present invention resides in the discovery that certain dicarboxylic acids are effective in the treatment of these conditions, and represents a departure from the types of skin conditions on which such acids have previously been disclosed as effective.
U.S. Pat. Nos. 4,292,326 (Nazarro-Porro, Sept. 29, 1981) and 4,386,104 (Nazarro-Porro, May 31, 1983) disclose the use of dicarboxylic acids in the treatment of acne and melanocytic hyperpigmentary dermatoses. Acne is a sebaceous gland abnormality with inflammatory papules, pustules, and cysts and noninflammatory comedos. It afflicts teenagers and young adults. Melanocytic hyperpigmentary disorders are noninflammatory conditions involving an excess of melanin formation in the skin. The producing cells may be benign, premalignant, or malignant.
Nonacne inflammatory dermatoses are quite distinct from acne in a number of ways, including the distribution and morphology of lesions, the pathologic sites microscopically, the lack of spontaneous resolution, the types of and the response to treatment, and the age groups most susceptible. Infectious cutaneous diseases include all microbial and fungal invasive organisms and infestations that may be transmitted to other skin sites on the person or to other persons. Hair loss results from a variety of diseases including inflammatory conditions like alopecia areata and hormone hypersensitivity like male pattern baldness.
Rosacea is a chronic disease of the flush area of the face characterized by a heightened vascular response. It begins as a prominent intermittent flush which becomes permanent followed by telangectasias. Later papules and pustules but no comedos develop. It occurs most commonly in women over 30 years of age. Antibiotics and corticosteroids are commonly used for treatment, but response is usually poor.
Perioral dermatitis occurs primarily in young women and is characterized by erythema, papules, papulovesicles and intermittent eczematous plaques of the chin, nasolabial folds, and upper lip. Itching and burning are often present. The usual treatment consists of antibiotics and corticosteroids.
Seborrheic dermatitis is a histopathologically eczematous dermatosis characterized by poorly demarcated scaley erythematous patches with yellowish greasy scales. "Dandruff" is a mild form of this condition localized to the scalp. This disease may involve any one, several, or all of the following sites: scalp, eyebrows, glabella, paranasal and chin folds, ears and retroauricular sulci, presternal interscapular regions, pubic regions and intergluteal folds. Corticosteroids with tar, sulfur, or antibiotics give temporary control in some cases.
Psoriasis is a common chronic proliferative epidermal disease characterized by keratinocyte epidermal transit time being increased by ninefold. The lesions are sharply demarcated thick erythematous plaques with abundant white scale. The most commonly involved sites include elbows, knees, scalp, genitalia, and gluteal fold. Nail abnormalities are very common and joint disease occurs infrequently. Therapy ranges from topical tar, anthralin, and corticosteroids to systemic methotrexate, psoralens and ultraviolet A light, and ultraviolet B light.
Eczematous dermatitis is a pathologic state of epidermal spongiosus that is the end result of a variety of diseases. These include atopic diathesis, allergic and irritant contact reactions, photo allergic and photo toxic reactions, drug eruptions, and severe asteatosis. The site of the eruption depends on the insulating disease. Current therapy consists of topical and systemic corticosteroids and topical tar.
Tinea cruris "jock itch" is a fungal or fungal/yeast infection of the groin and pubic areas. The infecting organisms may spread to other skin areas and may be transmitted to other people. Present therapy consists of topical and systemic antibiotics.
These are examples of conditions for which it has been discovered that dicarboxylic acids within the scope of the present invention are an effective treatment when applied topically. In general, the invention applies to nonacne inflammatory and infectious conditions of the skin or the skin regions such as, for example, the dermis, epidermis and adnexa, and also to alopecias resulting from inflammatory disease states or from hormonal abnormalities.
DETAILED DESCRIPTION OF THE INVENTION
The dicarboxylic acids of the present invention are those having 7 to 13 carbon atoms, inclusive. Preferred such acids are saturated aliphatic acids, particularly straight-chain species. Those having 8-10 carbon atoms are the most preferred. Examples include azelaic (1,9-nonanedioic) acid, suberic (1,8-octanedioic) acid, sebacic (1,10-decanedioic) acid, and pimelic (1,7-heptanedioic) acid. The invention also extends to mercapto derivatives of such acids, including mono- and dimercapto derivatives, as well as salts such as, for example, sodium.
The compounds are generally applied in dermatological formulations. These include any of the various known mixtures and combinations which may be applied topically and which will permit even spreading of the active ingredient over the affected area. Examples include creams, lotions, solutions, ointments and unguents.
The concentration of the dicarboxylic acid in the formulation is not critical and may vary over a wide range. The acid concentration may indeed range as high as the upper limit of dissolvability in any given formulation. In most cases, however, best results are achieved within a range of about 2% to about 40% by weight, preferably from about 15% to about 20% by weight.
The formulation may contain additional ingredients on an optional basis, including both those which are biologically active and those which are biologically inactive. Keratolytic agents are particularly useful in some cases as added active ingredients. Examples are salicylic acid, sulfur and retinoid derivatives. Optional concentrations will vary among keratolytic agents. Salicylic acid, for example, is preferably used at about 0.5% to about 5.0%, while sulfur is preferably used at about 2.0% to about 10.0%. Appropriate concentration ranges for any particular keratolytic agent will be apparent to those skilled in the art. Examples of inactive ingredients are wetting agents, surfactants, emollients, and solvents.
The term "therapeutically effective amount" is used herein to denote any amount which will cause a substantial improvement in a disease condition (such as a subsidence of a lesion, for example) when applied to the affected area repeatedly over a period of time. The amount will vary with the condition being treated, the stage of advancement of the condition, and the type and concentration of formulation applied. Appropriate amounts in any given instance will be readily apparent to those skilled in the art or capable of determination by routine experimentation.
The compositions are generally applied in topical manner to the affected area, i.e., localized application to the skin region where the inflammation or abnormality is manifest.
The following examples are offered for illustrative purposes, and are intended neither to limit nor define the invention in any manner.
EXAMPLE 1
FORMULATIONS
Formulation A:
A vessel was charged with 10 grams of azelaic acid and 10 milliliters of absolute ethyl alcohol, and heated slowly until warm. To the resulting solution was added 50 milliliters of Vehicle/N or Solvent G. These are identical nonprescription solvent mixtures consisting of 47.5% ethyl alcohol, 4% isopropyl alcohol and purified water, laureth-4, and propylene glycol. Vehicle/N is obtained from Neutrogena Dermatologicals of Los Angeles, Calif. Solvent G is obtained from Syosset Laboratories, Inc. of Syosset, N.Y.
Formulation B:
One pound of Cetaphil cream and 90 grams of azelaic acid were heated separately until each was liquified (approximately two hours). Cetaphil cream is a commercially available nonprescription mixture of water, ethyl alcohol, propylene alcohol, sodium lauryl sulfate, stearyl alcohol, methylparaben, propylparaben and butylparaben obtainable from Owen Laboratories, San Antonio, Tex. Once the cream and acid were liquified, the acid was slowly beat into the cream to form a smooth homogeneous cream.
EXAMPLE 2
APPLICATION
Four patients with perioral dermatitis and ten patients with rosacea which had proved to be refractory to standard therapies applied either Formulation A or Formulation B above to the affected areas twice daily. After four to twelve weeks of such application, all lesions of perioral dermatitis and eight of the ten with rosacea had cleared.
EXAMPLE 3
APPLICATION
Sixteen patients suffering from refractory scalp seborrheic dermatitis applied Formulation A to their scalps twice daily. Over periods of time ranging from six to forty-two days of use, fourteen of the sixteen patients showed either significant reduction or complete clearing of the condition.
EXAMPLE 4
APPLICATION
Three patients suffering from eczematous dermatitis on the face and/or extremities applied Formulation B to the lesions three times daily for 6 weeks. The lesions substantially or completely cleared.
EXAMPLE 5
APPLICATION
Fourteen patients suffering from psoriasis were treated with either Formulation A or Formulation B applied twice daily to lesions on one half of the body. The treated lesions of eight patients substantially improved after four to twelve weeks but all the itching had resolved.
EXAMPLE 6
APPLICATION
Three patients with tinea cruris all cleared completely after two weeks of Formulation A or B used twice daily.
EXAMPLE 7
APPLICATION
Individual patients suffering from male pattern baldness and alopecia areata used Formulation B for 12 weeks three times daily. Spotty terminal hair growth developed. The new growth occurred in the region of most recent hair loss. Another patient with erythrasma, a bacterial groin infection, cleared with twice daily application of Formulation A for 2 weeks. A patient with flat warts improved with four weeks application of Formulation B twice daily. | Dermatoses involving nonacne inflammatory dermatoses, infectious cutaneous diseases, and hair loss resulting from inflammation or hormonal anomalies are treated with dicarboxylic acids containing 7 to 13 carbon atoms, or certain mercapto derivatives or salts thereof. | 8 |
The present invention generally relates to an apparatus for controlling the opening or closing of a cover or hatch on a motor vehicle, and more particularly to an apparatus for conveniently controlling the opening or closing of a forward tilting hood of a medium- or heavy-duty truck or highway tractor.
BACKGROUND OF THE INVENTION
Forward tilting truck hoods are typically attached to the body or frame of a truck by means of one or more hinges, pins, or other types of revolute joint. Latches, hooks, rubber straps, and the like are used to keep the hood shut during normal operation. Prior to opening the hood, the latches or other fastener must be unfastened. Because these fasteners typically are located on either side of the hood opposite the hinge, the operator must move to various locations to operate the fasteners. For example, an operator may have to unfasten an elastic hold down on each side of the truck cab near a rear portion of the hood. Other fasteners may be operated remotely from in the cab by a cable, solenoid, or other mechanism.
After operating the latches or fasteners that hold the hood shut, the operator then typically moves to the front of the truck. From this position the top front portion of the hood may be pulled so that the hood rotates forward about the hinge pivot axis, giving the operator access to the engine and other vehicle components located under the hood.
The weight of the hood of a typical large truck may easily exceed 100 pounds. A hood may also have sharp angular edges, protruding bolts, and the like. Thus, an unrestrained truck hood presents a risk of injury should it fall open or shut in an uncontrolled manner. For example, an open hood may be blown shut unexpectedly by a sufficiently strong wind. To prevent such occurrences, a locking mechanism is typically provided to prevent inadvertent closure of a forward tilting truck hood.
When closing the hood an operator first must release the locking mechanism that prevents inadvertent hood closure. Typically, this requires the operator to move to a position beside the hood so that he may reach the locking mechanism. Often the locking mechanism is located under the hood in the vicinity of the hinge. Thus, while releasing the locking mechanism the operator may be in a position in which he is vulnerable if the hood were to shut accidentally.
After releasing the locking mechanism, the operator moves to the front of the truck and lifts the hood so that it rotates up and back about the hinge pivot axis. When the hood is fully shut, the operator then moves to various other locations around the truck to operate one or more latches or other devices that keep the hood securely shut.
Thus, an operator desiring to open or shut a typical forward tilting hood of a large truck has to move to several locations around the truck to operate various securing mechanisms, to release locking mechanisms, and to open or shut the hood. It would therefore be desirable to provide a mechanism that enables the operator to conveniently operate securing and locking mechanisms and reposition the hood from a single convenient position near the front of the truck.
SUMMARY OF THE INVENTION
The above, and other objects and advantages of the present invention are provided by an operating mechanism located near a top front portion of a truck hood. The operating mechanism may be coupled to a release mechanism so that actuation of the operating mechanism releases the hood so that it may be opened. The release mechanism may also be coupled to a locking mechanism that prevents the hood from closing inadvertently. Thus, an operator is able to operate the latching and locking mechanisms, and open or shut the hood, from a single location near the front of the truck.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will be understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
FIG. 1 is an oblique exploded view of an illustrative embodiment of an operating mechanism in accordance with the principles of the present invention;
FIGS. 2A and 2B are two sectional views showing the operating mechanism of FIG. 1 in normal and actuated positions, respectively;
FIG. 3 is an oblique view of a locking device for preventing unintended closure of a forward tilting truck hood, in accordance with the principles of the present invention;
FIGS. 4 through 6 are sectional views of locking device of FIG. 3 , shown at various stages of opening a truck hood;
FIG. 7 is shows an alternative method of unlocking the locking device of FIG. 3 .
DETAILED DESCRIPTION
Referring first to FIG. 1 , operating mechanism 10 includes movable handle 12 , disposed near hand recess 14 in hood 16 . Preferably, hand recess 14 is located along a top front edge of hood 16 and has a suitable size and shape to permit entry of an operator's hand. Movable handle 12 includes pivots 18 extending from opposite ends thereof, which are configured to fit corresponding recesses 20 in hood 16 .
As shown in FIGS. 2A and 2B , link 26 is operatively coupled to movable handle 12 by means of pin 28 . In the illustrative embodiment of the present invention, a cable or other type of operative interconnect may also be used. Shrouds or guards 30 extending from movable handle 12 on both sides of link 26 may be provided to prevent an operator's hand or fingers from being pinched during operation of operating mechanism 10 .
As shown in FIG. 1 , movable handle 12 including pivots 18 , pin 28 , and shroud 30 , comprises a unitary structure preferably formed from injection molded plastic. Alternatively, movable handle 12 may comprise an assemblage of multiple parts.
Fixed handle 22 is disposed adjacent to movable handle 12 and is fastened to hood 16 using bolts 24 , or other suitable means, so that pivots 18 are retained in recesses 20 . An ornamental fascia such as grille work 32 of FIGS. 2A and 2B (not shown in FIG. 1 ) may be mounted to hood 16 so as to hide operating mechanism 10 from view.
When operating mechanism is not being used, the weight of link 26 , the elastic resilience of pivots 18 , a spring (not shown), or some other biasing means causes movable handle 12 to assume the position shown in FIG. 2A . To use operating mechanism 10 , an operator grasps movable handle 12 and fixed handle 22 , for example, by inserting their fingers into hand recess 14 . Squeezing movable handle 12 toward fixed handle 22 causes movable handle 12 to rotate or pivot about pivots 18 . As shown in FIG. 2B , this causes link 26 to be pulled upward by pin 28 . Movement of link 26 may in turn operate a remote mechanism or device. For example, link 26 may be coupled to latching device 36 of FIG. 3 . When an operator releases his movable handle 12 , movable handle 12 returns to the position shown in FIG. 2A due to the biasing means described above.
The operating mechanism thus described in connection with FIGS. 1 , 2 A, and 2 B provides a convenient device for operating remote mechanisms such as hood release mechanisms and the like. Although operating mechanism 10 is shown with a single mechanical linkage, other arrangements may be used. For example, multiple movable handles and linkages may be provided so that several remote mechanisms may be operated. In addition, movable handle 12 may operate a switch that in turn activates a relay, solenoid, or the like.
Turning now to FIG. 3 an oblique view is shown of latching device 36 which prevents inadvertent closure of a truck hood. Latching device 36 includes latch bar 38 pivotally coupled to vehicle frame cross member 40 and release lever 42 pivotally mounted to hood cross member 44 . For example, latch bar 38 may be attached by pin 45 to bracket 43 which may be bolted or welded to vehicle frame cross member 40 . Similarly, release lever 42 may be connected by pin 48 to bracket 46 , which in turn is connected to hood cross member 44 . Torsion spring 47 or other means biases latch bar 38 toward release lever 42 so that latch bar 38 fits into slot 50 therein. Pin 52 keeps latch bar 38 engaged within slot 50 . Preferably, slot 50 includes portion 54 that is wide enough to permit pin 52 to pass through when latching device 36 is being assembled or disassembled. Strut 56 may be used to hold latch bar 38 in a released position to facilitate assembly of the hood to the vehicle.
Operation of latching device 36 is now described in connection with FIGS. 4 through 6 . FIG. 4 shows latching device 36 when the hood is in a fully shut position. In the shut position, latch bar 38 is biased against hood cross member 44 . When the hood is pivoted open about pivot 58 of hinge 60 (shown in phantom) latch bar 38 slides in slot 50 . As shown in FIG. 5 , torsion spring 47 keeps latch bar 38 biased against hood cross member 44 . As shown in FIG. 4 , latch bar 38 includes notch 62 and projecting portion 64 in the free end thereof. When the hood is nearly fully open, hood cross member 44 slides under latch bar 38 into notch 62 as shown in FIG. 6 . Projecting portion 64 of latch bar 38 comes to rest on an upper portion of hood cross member 44 .
With hood cross member 44 positioned in notch 62 , accidental closure of the hood is substantially prevented. If the hood is moved toward a closed position, either manually or due to a gust of wind or the like, a corner of hood cross member 44 contacts latch bar 38 at notch 62 . Contact with latch bar 38 hinders further closing of the hood. Preferably, the relative positions of latch bar 38 and hood cross member 44 , and the shape of notch 62 are designed so that any force of hood cross member 44 applied to notch 62 in latch bar 38 results in a small tangential force tending to further seat latch bar 38 against hood cross member 44 . Hood cross member 44 may include suitable reinforcement to withstand forces and wear caused by contact with notch 62 in latch bar 38 .
The release of latching device 36 is shown in FIG. 7 . Link 26 is pivotally connected to release lever 42 by pin 70 , or other suitable means. When operated by a suitable mechanism, e.g., operating mechanism 10 of FIG. 1 , link 26 causes release lever 42 to pivot on pin 48 to the position shown. An end of slot 50 contacts and lifts latch bar 38 so that notch 62 is clear of hood cross member 44 . With latch bar 38 in this raised position, the hood can then be closed.
Strut 56 provides an alternative means of releasing latch bar 38 if, for some reason, it is not possible to operate link 26 . For example, a vehicle may be parked such that access to operating mechanism 10 on the open hood is obstructed by another truck or other object. To release latching device 36 , latch bar 38 is lifted so that hood cross member 44 is clear of notch 62 . Strut 56 is then rotated upward and positioned so that an end of strut 56 fits into notch 66 in the lower edge of latch bar 38 as shown in phantom lines in FIG. 7 . Strut 56 prevents torsion spring 47 from forcing latch bar 38 back down against hood cross member 44 , and thereby permits the hood to be moved to the shut position. When the hood is being shut, an upper portion of hood cross member 44 comes into contact with the lower edge of latch bar 38 , lifting it upward. The upward motion of latch bar 38 releases strut 56 from notch 66 , and strut 56 returns to its reset position as shown in FIG. 4 . Additional notches may be provided in the lower edge of latch bar 38 to hold latch bar 38 in other positions. For example, notch 68 may be provided that holds latch bar 38 in a near vertical orientation so that it is out of the way while the hood is being mounted to the vehicle.
Thus, a latching device and remote operating mechanism particularly suited for use in opening or closing a forward tilting hood of a motor vehicle has been disclosed. It will be readily apparent that the mechanisms thus disclosed may be useful for other applications and that various modifications may be made to the disclosed embodiment without departing from the spirit and scope of the invention. Accordingly, one will understand that the description provided herein is provided for purposes of illustration and not of limitation, and that the invention is limited only by the appended claims. | A latching device and operating mechanism are provided suitable for controlling the opening or closing of a tilting cover such as the hood of a car or truck. The latching device operates to prevent accidental closure of the cover when the cover is open. The operating mechanism is coupled to the latching device for releasing the latching device when the hood is to be shut. The operating mechanism is located on the vehicle near a location from which an operator typically opens or closes the hood. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas recirculation control system, and, more particularly, relates to an exhaust gas recirculation control system which is particularly suited for application to a diesel engine.
The exhaust gas recirculation in diesel engines is to replace a part of the air inhaled into the cylinders of the engine that is generally in excess of that which is required for combustion of the fuel injected into the cylinders of the engine, by recirculated exhaust gas, in order to suppress emission of harmful NOx pollutants. In this diesel engine exhaust gas recirculation, it is desirable that the amount of air which is replaced by exhaust gas should be proportional to the amount of air which is in excess of the actual air requirement for combustion of the actual amount of fuel injected, so that maximum possible amount of excess air is reduced from the air/gas flow supplied to the cylinders of the engine, without causing unstable combustion of fuel in the cylinders, while accomplishing maximum effect of suppressing NOx emission, over the entire operational region of the engine. Since the excess air ratio in the diesel engine decreases as the load on the engine increases, it is necessary to control the exhaust gas recirculation quantity so that the exhaust gas recirculation ratio decreases, as the load on the engine increases. The exhaust gas recirculation ratio is defined as the ratio of the quantity of exhaust gas recirculated and introduced into the inlet system of the engine so the total quantity of inlet gases inhaled by the engine, which is the sum of the quantity of the recirculated exhaust gases and the amount of fresh air inhaled by the engine.
The power output of or the load on a diesel engine is controlled by the amount of fuel injected per unit time, and, therefore, it is not generally possible, with a diesel engine, to perform control of exhaust gas recirculation, according to the load on the engine, by using a diaphragm operated type exhaust gas recirculation control valve which responds to inlet manifold vacuum, as is done commonly with gasoline engines. Accordingly, therefore, in the prior art, in a diesel engine the conventional exhaust gas recirculation control valve has been directly connected to and operated by either the accelerator pedal linkage of the vehicle, or the control lever of the fuel injection pump, so that the exhaust gas recirculation control valve has been operated according to the operation of the accelerator lever, or the control lever.
This form of control means for exhaust gas recirculation is fairly easy and simple to manufacture, but there is a problem that it tends to increase the amount of force required for manipulation of the accelerator pedal, and thereby may deteriorate the operational feeling of the accelerator pedal and therefore the drivability of the vehicle.
As an alternative system for controlling diesel exhaust gas recirculation, there has been proposed a system which comprises a diaphragm type exhaust gas recirculation control valve, the diaphragm device being actuated by vacuum provided by a pneumatic governor diaphragm chamber installed in the fuel injection pump. However, with this system of exhaust gas recirculation control, the problem arises that it is not really possible to obtain enough power for operating the exhaust gas recirculation control valve from the vacuum supplied by the pneumatic governor diaphragm chamber, because the vacuum present in this pneumatic governor diaphragm chamber is basically relatively small. Further, because of this, there arises the problem that the position of the exhaust gas recirculation control valve may be directly displaced by the dynamic pressure of the inlet air flow and/or the recirculating exhaust gas flow.
As another possible solution to the problem of diesel exhaust gas recirculation control, the possibility has been explored of controlling exhaust gas recirculation quantity continuously to the appropriate and correct value by measuring the amount of fuel injected to the combustion chambers of the engine per one cycle, and by opening and closing an exhaust gas recirculation control valve by a pressure type and/or electric type actuator, based upon these measurements. However, in this case, the control system as a whole becomes very complicated, and various problems occur when it is in practice mounted to an operating automobile.
SUMMARY OF THE INVENTION
The present invention arises from the remarking by the present inventor of the fact that, although theoretically and desirably the ratio of exhaust gas recirculation should be varied smoothly and continuously as the load on the engine varies, in actual practice this smooth variation is not strictly necessary for effective control, and in practice if the rate of exhaust gas recirculation were varied in a two step manner, this would provide a very satisfactory improvement in performance over ON/OFF control. That is, although the ideal curve of the relationship between engine load and exhaust gas recirculation ratio should be a smoothly curved line, nevertheless an approximation to this smoothly curved line by a two step bar chart, if it provides advantages with regard to simplicity, cost of manufacture and reliability of operation, may be acceptable.
Therefore, it is the object of the present invention to provide an exhaust gas recirculation control system, for a diesel engine, which is simple, and yet provides a performance of control of exhaust gas recirculation ratio which approximately satisfies the ideally required characteristics for exhaust gas recirculation.
This, and other, objects, are achieved, according to the present invention, in a diesel engine, comprising an exhaust system, an inlet system, and an exhaust gas recirculation system, by an exhaust gas recirculation control system, comprising: an exhaust gas recirculation control valve, which controls the amount of exhaust gas recirculated from the exhaust system of the engine to the inlet system through the exhaust gas recirculation system; and a means for actuating the exhaust gas recirculation control valve, which positions the exhaust gas recirculation control valve selectively and steppedly at one of three states, that are: a first state in which it provides substantially zero exhaust gas recirculation ratio, a second state in which it provides a medium exhaust gas recirculation ratio, and a third state in which it provides a maximum exhaust gas recirculation ratio, according to the load on the engine.
According to a particular feature of the present invention, the exhaust gas recirculation control valve actuating means may conveniently comprise a multi-action diaphragm actuator which includes first and second diaphragms which define first and second diaphragm chambers and a stem operatively related with the first and second diaphragms, the stem being located at a first shift position when either of the first and second diaphragm chambers is not supplied with operating fluid pressure, at a second shift position when only the first diaphragm chamber is supplied with operating fluid pressure, and at a third shift position when both the first and second diaphragm chambers are supplied with operating fluid pressure, and a fluid flow control means which controls supply of the operating fluid pressure to the first and second diaphragm chambers according to the load on the engine.
According to a further particular feature of the present invention, the operating fluid pressure supply control means may desirably comprise an electric switch which detects displacement of a fuel metering element such as a control lever, a control rack, or a spill ring of a fuel injection pump in three stages, and first and second electromagnetic valves which are controlled by the switch and control supply of the operating fluid pressure to the first and second diaphragm chambers, respectively.
According to another particular feature of the present invention, the operating fluid pressure which is controlled by the two electromagnetic valves may be a fluid pressure produced by a pump operated by the diesel engine.
Further, according to yet another particular feature of the present invention, the exhaust gas recirculation control valve may desirably be so adapted that, when exhaust gas recirculation ratio is increased, it further restricts the passage of intake fresh air. As, in a diesel engine, the vacuum present in the inlet manifold is relatively low (that is, the pressure therein is relatively near atmospheric) compared to that present in the inlet manifold of a gasoline engine, there is a possibility that the actual amount of exhaust gas recirculated cannot be increased by more than a certain amount, even when the exhaust gas recirculation control valve is quite wide open, if it is provided in the exhaust gas recirculation passage, especially when the engine load is low. On the other hand, if, as explained above, the intake air passage is more throttled, by the exhaust gas recirculation control valve, when the exhaust gas recirculation ratio is to be increased, the absolute amount of exhaust gas recirculated increases to approximately the same extent as the amount of inhaled fresh air is decreased. By this arrangement, even at low engine load, it is possible to obtain the necessary exhaust gas recirculation ratio, and the necessary amount of recirculation of exhaust gases.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the following description of several preferred embodiments thereof, which is to be taken in conjunction with the accompanying drawings. It should be clearly understood, however, that the description of the embodiments, and the drawings, are all of them provided purely for the purposes of illustration and exemplification only, and are in no way to be taken as limitative of the scope of the present invention. In the drawings:
FIG. 1 is a somewhat schematic diagram, showing a diesel engine which is equipped with an embodiment of the exhaust gas recirculation control system of the present invention;
FIG. 2 is a sectional illustration of part of the embodiment of the exhaust gas recirculation control system of the present invention, which incorporates a flapper-type exhaust gas recirculation control valve, and of part of the intake duct of the diesel engine, showing their construction in detail;
FIG. 3 is a side view particularly showing an electrical switching system incorporated in the exhaust gas recirculation system of the present invention;
FIG. 4 is a graph, in which engine torque is the ordinate and engine rpm is the abscissa, showing an example of three lines A, B, and C, which divide from one another the three stages of operation I, II, and III, effected by the exhaust gas recirculation control system according to the present invention;
FIG. 5 is a graph, in which exhaust gas recirculation ratio is the ordinate and engine torque is the abscissa, showing an example of the three-stage performance of exhaust gas recirculation, effected by the exhaust gas recirculation control system of the present invention; and
FIG. 6 is a view similar to FIG. 2, partially in cross section, of a second embodiment of the exhaust gas recirculation control device according to the present invention, in which a different type exhaust gas recirculation control valve is used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, the reference numeral 1 denotes a diesel engine which inhales air through an air cleaner 2, an inlet duct 3, in which an exhaust gas recirculation control valve 4 is incorporated, and an inlet manifold 5, mixes with this air and combusts it in the combustion chambers, the fuel being injected directly into the combustion chambers by a fuel injection pump 7, and exhausts exhaust gases through an exhaust manifold 6.
Fuel injection valves corresponding to the various cylinders of the engine are incorporated in the engine so as each to be giving, on every compression stroke of the corresponding piston, a prescribed amount of liquid fuel, at high pressure, from the fuel injection pump 7, and to inject this prescribed amount of liquid fuel into the corresponding cylinder of the engine. The size of this prescribed amount of liquid fuel is regulated by the position of a control lever 9 of the fuel injection pump 7. One end of this control lever 9 is connected to one end of a shaft 8, as can be schematically seen in FIG. 1, and the shaft 8 extends into the fuel injection pump 7 and directly controls its output amount. The other end of this control lever 9 is pivotally connected by a pin 10 (FIG. 3) to the accelerator pedal (not shown) of the automobile in which this diesel engine is incorporated, through a linkage system which is not shown in the figures. When the accelerator pedal of the vehicle is depressed, the control lever 9 is rotated in the clockwise direction, as seen in FIG. 3, and this direction of rotation of the control lever 9 and the shaft 8 is in the direction of increasing the magnitude of the above mentioned prescribed amount of charge of liquid fuel supplied to each cylinder of the engine on its compression stroke.
Thereby, the load on the engine, that is to say, the amount of power developed by the engine, is increased, according to the clockwise rotation of the above mentioned control lever 9 or the associated shaft 8 of the fuel injection pump 7, due to the progressive depression of the accelerator pedal of the vehicle.
An exhaust gas recirculation passage 11 is provided with its one end connected to a middle portion of the exhaust manifold 6 and the other end connected to the exhaust gas recirculation control valve 4. Through this exhaust gas recirculation passage 11, a part of the exhaust gas produced by the diesel engine 1 is recirculated and directed to the inlet manifold 5, and the amount of flow of this exhaust gas is controlled in an ongoing fashion by the exhaust gas recirculation control valve 4.
Referring particularly now to FIG. 2, which shows the exhaust gas recirculation control valve 4 in more detail, this exhaust gas recirculation control valve 4, which in this embodiment is a flapper-type exhaust gas recirculation control valve, comprises a casing 13, which is generally connected between the inlet manifold 5 and the inlet duct 3, and which defines within itself an inlet passage 12, which connects the inlet duct 3 to the inlet manifold 5. On one side of this casing 13 (the upper side in FIG. 2), is connected an elbow pipe 15, which opens into the inlet passage 12 via an exhaust gas recirculation valve seat 14. The end of the elbow pipe 15 remote from the casing 13 is connected, by a nut 16, to an end of a tubular element which constructs the exhaust gas recirculation passage 11.
Further, the casing 13 supports rotatably a shaft 17, and on this shaft 17, inside the inlet passage 12, is fixedly attached one edge of the flapper valve element 18. Thus, this flapper valve element 18 is so adapted that it may move between a position, designated in FIG. 2 by I, in which it rests against the exhaust gas recirculation valve seat 14 and completely closes off the elbow pipe 15, and therefore the exhaust gas recirculation passage 11, from communication with the inlet passage 12, through an intermediate position, designated in FIG. 2 by II, in which it is partly moved away from this contact with the exhaust gas recirculation valve seat 14 so as to allow partial or restricted communication of the elbow pipe 15, and therefore the exhaust gas recirculation passage 11, with the inlet passage 12, to a third position, designated in FIG. 2 by III, in which it is moved so far away from contact with the exhaust gas recirculation valve seat 14 that the communication of the elbow pipe 15, and therefore the exhaust gas recirculation passage 11, with the inlet passage 12 is substantially free, with no substantial restriction being applied thereto by the flapper valve element 18. Further, according to a particular feature of this embodiment of the present invention, when the flapper valve element 18 is in this third position III, which is the full open position wherein the elbow pipe 15 and the exhaust gas recirculation passage 11 are substantially connected with the inlet passage 12 with no substantial restriction being applied therebetween, the flapper valve element 18 is also at this time providing substantial restriction to the flow of fresh air from the air cleaner 2, through the inlet duct 3, and through the inlet passage 12 to the inlet manifold 5.
The shaft 17 is biased in the anticlockwise direction in FIG. 2 by a twisted coil spring which is not shown in the drawings. Further, one one end of the shaft 17 (outside the casing 13) there is fixedly connected one end of a lever 19, and to the other end of this lever 19 there is pivotally connected one end of a connecting rod 20. The other end of this connecting rod 20 is connected to the multi-action diaphragm actuated control device 21, which will be explained hereinafter, and, as will be seen, by the action of the multi-action diaphragm activated control device 21, via the connecting rod 20, the lever 19, and the shaft 17, the flapper valve 18 is moved between its various positions I, II, and III. The length of the connecting rod 20 may be adjusted by an adjusting device 72, which adjusts its effective length.
The multi-action diaphragm activated control device 21 is fixed to the casing 13 of the exhaust gas recirculation control valve 4 by a mounting device 22. This multi-action diaphragm activated control device 21 comprises a first diaphragm 24 and a second diaphragm 25. These diaphragms 24 and 25 are fitted within a casing 23, in a stacked relationship, and, as seen in FIG. 2, the first diaphragm 24 defines an atomospheric pressure chamber 26 above itself, between itself and the casing 23. Further, between the first diaphragm 24 and the second diaphragm 25 and the casing 23, there is defined a first diaphragm chamber 27, and, further, the second diaphragm 25 defines a second diaphragm chamber 28 below itself, between itself and the casing 23.
An operating rod 31 is connected, at its one end, to the first diaphragm 24 by discs 29 and 30, and the other end of this operating rod 31 is connected to the connecting rod 20, via a slot 32, which allows a certain amount of free play between the connecting rod 20 and the operating rod 31. Further, the second diaphragm 25 supports, above it in FIG. 2, a first stopper 36, via discs 33 and 34, and a connecting member 35. Further, a fixed stopper plate 37 is mounted to the casing 23, above the second diaphragm 25, so that the second diaphragm 25 is prevented from moving upwards in FIG. 2 further than a certain predetermined position, by the coming into contact of the fixed stopper plate 37 and the disc 33, which is attached to the second diaphragm 25 on its upper side. Further, to the casing 23, below the second diaphragm 25, there is fixed a second stopper 38, which therefore restricts movement downwards in FIG. 2 of the second diaphragm 25 beyond another certain predetermined position. The position of this second stopper 38 may be adjusted in height and fixed in the vertical direction in FIG. 2 by the use of an adjusting screw 39.
Between the first diaphragm 24 and the second diaphragm 25 there is fitted a first compression coil spring 41, which bears between the disc 30 and the disc 33, and between the second diaphragm 25 and the lower part in FIG. 2 of the casing 23 there is fitted a second compression coil spring 42, both these compression coil spring 41 and 42 being fitted at a predetermined loading. Through the casing 23, there are fitted a first inlet port 43, which leads a fluid pressure (vacuum in this embodiment) the production of which will be explained hereinunder into the first diaphragm chamber 27, and a second inlet port 44, which leads another fluid pressure (also vacuum in this embodiment) the production of which will be explained later into the second diaphragm chamber 28.
The operation of this multi-action diaphragm activated control device 21 is as follows.
When vacuum is not supplied to either of the first inlet port 43 and the second inlet port 44, then neither the first diaphragm chamber 27 nor the second diaphragm chamber 28 is supplied with vacuum, but these diaphragm chambers 27 and 28 are both supplied with atmospheric pressure, and then, at this time, the multi-action diaphragm activated control device 21 is in the state shown in FIG. 2, by the biasing actions of the compression coil springs 41 and 42, and the flapper valve 18 is turned in the anticlockwise direction by the action of the spring (not shown), as seen in FIG. 2, so that this flapper valve 18 is kept in the full closed position I, as seen in FIG. 2, wherein it closes off completely the passage of recirculated exhaust gases. On the other hand, if vacuum which is greater than a predetermined value is introduced into the first diaphragm chamber 27 via the first inlet port 43, the first diaphragm 24 is moved downwards in FIG. 2 to a position where the disc 30 attached to its lower side is in contact with the first stopper 36, against the opposing spring force of the first compression coil spring 41, and thereby the lever 19 is rotated, via the operating rod 31 and the connecting rod 20, in the clockwise direction in FIG. 2, through a first predetermined angle. By this rotation of the lever 19, via the shaft 17, the flapper valve 18 is moved to the half open position, which is shown as II in FIG. 2, wherein the passage of recirculated exhaust gases is allowed at a certain intermediate amount.
Yet further, if vacuum which is greater than certain predetermined values is introduced into both the first diaphragm chamber 27 and the second diaphragm chamber 28 at the same time, via the first inlet port 43 and the second inlet port 44, respectively, then the second diaphragm 25 will move downwards in FIG. 2 to the position where the disc 34 attached to its lower side is in contact with the second stopper 38, against the spring force of the second compression coil spring 42, and also, as described above, the first diaphragm 24 will move downwards in FIG. 2 to the position where the disc 30 attached to its lower side is in contact with the first stopper 36, which is attached to the upper side of the second diaphragm 25. Thus, in this state, the first diaphragm 24 is moved to a lower position in the figure than was the case in the above described set of circumstances in which only the first diaphragm chamber 27, and not the second diaphragm chamber 28, was supplied with vacuum, and thereby the lever 19 is rotated, via the operating rod 31 and the connecting rod 20, in the clockwise direction through a second predetermined angle which is greater than the first predetermined angle described above. Thereby, via the shaft 17, the flapper valve 18 is moved in the clockwise direction to its full open position shown in FIG. 2 by III, wherein it substantially does not hinder the passage of recirculated exhaust gases.
Thereby, according to selective supply of vacuum to the first inlet port 43 or to both the first and second inlet ports 43 and 44 of the multi-action diaphragm activated control device 21, this multi-action diaphragm activated control device 21 provides a two-step performance of moving the flapper valve 18.
Supply of vacuum to the first inlet port 43 of the multi-action diaphragm activated control device 21, and therefore to the first diaphragm chamber 27 thereof, is provided, from a vacuum generating pump 49, which in this embodiment is coupled, as may be schematically seen in FIG. 1, to the diesel engine 1, via pipes 48 and 47, a first electromagnetic valve 46, and a pipe 45. Thus, by the opening and closing operation of the first electromagnetic valve 46, supply of vacuum may be selectively provided to the first diaphragm chamber 27 of the multi-action diaphragm activated control device 21. It should be noted that the first electromagnetic valve 46 is so adapted that, when it is not providing supply of vacuum from the pump 49 to the first inlet port 43 and the first diaphragm chamber 27 of the multi-action diaphragm activated control device 21, it is providing atmospheric pressure thereto instead.
Further, supply of vacuum to the second inlet port 44 of the multi-action diaphragm activated control device 21, and thereby to the second chamber 28 thereof, is provided, from the pump 49, via pipes 48 and 52, a second electromagnetic valve 5, and a pipe 50. Thereby, the vacuum generated by the pump 49 is selectively introduced to the second diaphragm chamber 28 of the multi-action diaphragm activated control device 21, under the control of the second electromagnetic valve 51. It should be noted that the second electromagnetic valve 51 is so adapted that, when it is not providing supply of vacuum from the pump 49 to the second inlet port 44 and the second diaphragm chamber 28 of the multi-action diaphragm activated control device 21, it is providing atmospheric pressure thereto instead.
The structure of the first and second electromagnetic valves 46 and 51 may be the same, and, in the shown embodiment, it is. Each of them has a valve element 55 or 60 which is movable to the right in FIG. 2, so as to block the atmosphere inlet port 56 or 61, by magnetic force generated by an electromagnetic coil 53 or 58, and which is also movable to the left in FIG. 2, so as to block the negative pressure port 54 or 59, by negative pressure which is present in the negative pressure port 54 or 59. This negative pressure port 54 or 59 is connected, via a pipe 47 or 52, to the pipe 48 which leads to the vacuum generating pump 49.
Thus, when the electromagnetic coil 53 or 58 receives supply of electric current, then it provides magnetic force, and the valve element 55 or 60 is attracted rightwards in FIG. 2, and thereby the negative pressure port 54 or 59 is communicated with the outlet ports 57 or 62, which is connected via the pipe 45 or 50 with the first inlet port 43 or the second inlet port 44 of the multi-action diaphragm activated control device 21, and further, by the rightward motion of the valve element 55 or 60, the atmospheric inlet port 56 or 61, which leads to the atmosphere, is closed.
On the other hand, when the electric coil 53 or 58 is not supplied with electric current, then it does not provide magnetic force, and thereby the valve element 55 or 60 is pulled leftwards in FIG. 2 by the vacuum which is present in the negative pressure port 54 or 59, and closes this vacuum negative pressure port 54 or 59. Therefore, the atmospheric inlet port 56 or 61 is communicated with the inlet port 57 or 62, and thereby, via the pipe 45 or 50, with the first inlet port 43 or the second inlet port 44 of the multi-action diaphragm activated control device 21.
The electromagnetic coils 53 and 58 of the first and second electromagnetic valves 46 and 51 are individually supplied selectively with electric current from a battery electric current source 63, under the control of an electric switching system 64, which is shown in more detail in FIG. 3. The electric switching system 64 comprises a first disc member 65 and a second disc member 66, which are both composed of insulating material, and which are fixedly attached to the shaft 8 of the diesel fuel injection pump 7. On the first disc member 65 and the second disc member 66 are mounted respectively a first contact plate 67 and a second contact plate 68, around parts of their circumferences, and these first and second contact plates 67 and 68 are made of electrically conducting material.
To one side of the shaft 8 are provided the first and second contact levers 69 and 70, which are electrically connected respectively to the coil 53 of the first electromagnetic valve 46, and to the coil 58 of the second electromagnetic valve 51, and which respectively bear upon the first contact plate 67 and the second contact plate 68, in a sliding and electrically conductive fashion. Further, the first contact plate 67 and the second contact plate 68 are grounded. Thereby, as the shaft 8 rotates to control the amount of diesel fuel provided to the cylinders of the engine by the diesel fuel injection pump 7, the first and second disc members 65 and 66 rotate, and the contact levers 69 and 70 slide along the contact plates 67 and 68, and establish electrical contact therewith, or break electrical contact therewith.
Thereby, the one ends of the coils 53 and 58 of the first and second electromagnetic valves 46 and 51 are selectively connected to ground. Further, as seen in FIG. 1, the other ends of these electric coils 53 and 58 of the first and second electromagnetic valves 46 and 51 are connected to the battery electric source 63. Thereby, according to the exact particular amount of rotation of the shaft 8 of the diesel fuel injection pump 7, one, both, or neither of the electromagnetic valves 46 and 51 may be energised.
In more detail, when the shaft 8 of the fuel injection pump 7 is in a position between the idling position of the pump, denoted by X in FIG. 3, and the position denoted by A, which is at a predetermined angle Ta away from the idling position X, the contact plate 67 is in electrical contact with the first contact lever 69, and thereby electrical power is supplied to the electromagnetic coil 53 of the first electromagnetic valve 46. Similarly, when the shaft 8 of the diesel fuel injection pump 7 is between the idling position of the pump X and the position denoted by B, which is at a second predetermined angle Tb away from the idling position X, said second predetermined angle Tb being a little smaller than the abovementioned first predetermined angle Ta, the second contact plate 68 is in electrical contact with the second contact lever 70, and thereby electrical power is provided to the electromagnetic coil 58 of the second electromagnetic valve 51.
Therefore, as the shaft 8 of the fuel injection pump 7 turns progressively between the idling position X and the engine full load or maximum power position C, which is at a third predetermined angle Tc away from the fuel injection pump 7 idling position, the operation of the electric switching device 64 is as follows.
First, when the shaft 8 of the fuel injection pump 7 is between the idling position X and the position B, which is at the angle Tb away from the idling position X, then the first contact plate 67 is in contact with the second contact lever 70. Therefore, electrical power is provided to both of the electromagnetic coils 53 and 58 of the first and the second electromagnetic valves 46 and 51. Thereby, the valve elements 55 and 60 of the first and second electromagnetic valves 45 and 61 are both attracted in the rightwards direction in FIG. 2, and thereby the negative pressure ports 54 and 59 are both communicated with their respective outlet ports 57 and 62, so that vacuum is provided from the pump 49 through the pipe 48, through both the pipes 47 and 52, through both the first and second electromagnetic valves 46 and 51, and through both the pipes 45 and 50 and the first inlet port 43 and the second inlet port 44, to both the first diaphragm chamber 27 and the second diaphragm chamber 28 of the multi-action diaphragm activated control device 21. Therefore, as described above, the multi-action diaphragm activated control device 21 opens the flapper valve 18 to its maximum open position, as shown in FIG. 2 by III, so that exhaust gas recirculation is performed to the maximum amount.
Further, according to the above described particular feature of this embodiment of the present invention, by the fact that in this condition the inlet passage 12 is restricted by the fully opened flapper valve 18, not only is the maximum amount of exhaust gas recirculation provided, according to the full open position of the flapper valve 18, but also the flow resistance of the inlet passage 12 to the flow of fresh air from the air cleaner 2 to the inlet manifold 5 is increased, and thereby the ratio of exhaust gas recirculation is further increased, which, as explained above, is very desirable.
Second, when the shaft 8 of the diesel fuel injection pump 7 is rotated beyond the position B, but not as far as the position A, so that the angle through which it has moved is greater than Tb but less than Ta, then the second contact plate 68 comes out of contact with the second contact lever 70, and only the first contact plate 69 remains in contact with the first contact lever 69. In this case, the electromagnetic coil 53 of the first electromagnetic valve 46 is provided with electrical power, and thereby its valve element 55 is moved rightwards in FIG. 2, thus communicating the negative pressure vacuum port 54 to the outlet port 57, and providing, via the pipe 45 and the first inlet port 43, the first diaphragm chamber 27 of the multi-action diaphragm activated control device 21 with vacuum from the pump 49, while, on the other hand, the electromagnetic coil 58 of the second electromagnetic valve 51 does not receive electrical power, and thereby its valve element 60 is moved leftwards in FIG. 2 and blocks the negative pressure port 59, while opening the atmospheric inlet port 61, whereby atmospheric pressure is introduced, via the pipe 50, and the second inlet port 44, to the second diaphragm chamber 28 of the multi-action diaphragm activated control device 21. Thereby, as explained above, the multi-action diaphragm activated control device 21 provides a position for the flapper valve 18, which is the intermediate or half open position denoted by II in FIG. 2, and thus reduces the amount of fluid flow of exhaust gas recirculation, as compared with the first situation described above, to an intermediate flow level.
Further, if the shaft 8 of the diesel fuel injection pump 7 is further rotated, beyond the angular position denoted by A, to a position between the angular position A and the angular position C, so that the angle through which it has moved from the idling position X is greater than Ta, then in this state the first contact plate 67 is out of contact with the first contact lever 69, and also the second contact plate 68 is out of contact with the second contact lever 70. Thereby, no electrical power is supplied to either the electromagnetic coil 58 of the second electromagnetic opening and closing valve 51. In this case, the valve elements 55 and 60 are both of them in their leftwards positions in FIG. 2, and thereby the negative pressure ports 54 and 59 are both closed, and the atmospheric inlet ports 56 and 61 are both open, whereby atmospheric pressure is introduced, via the pipes 45 and 50, and the first inlet port 43 and the second inlet port 44, to both the first diaphragm chamber 27 and the second diaphragm chamber 28 of the multi-action diaphragm activated control device 21. Thereby, as explained above, the multi-action diaphragm activated control device 21 provides a position for the flapper valve 18 which is the fully closed position, denoted by I in FIG. 2. Thereby, exhaust gas recirculation is effectively stopped.
Thus, it is seen that the electrical switching device 64 provides, selectively, a three-way signal, showing whether the amount of load upon the diesel engine, that is to say, the amount of fuel provided at each compression stroke of the piston of a cylinder of the engine to that cylinder by the diesel fuel injection pump 7, is either in a first region higher than a first predetermined value, in a second region between the first predetermined value and a second predetermined value, or in a third region below the second predetermined value. This three-way signal is acted on by the means which comprises the two electromagnetic valves 46 and 51, the multi-action diaphragm activated control device 21, and the exhaust gas recirculation valve 4, to provide a threeway performance of control of exhaust gas recirculation.
In FIG. 4 is shown a graph, in which engine torque is the ordinate and engine rpm is the abscissa, showing the characteristics of a diesel internal combustion engine, as regards the torque and rpm combinations provided by the above mentioned three positions of the shaft of the diesel fuel injection pump 7. Thus, the line denoted by A in FIG. 4 shows the various possible combinations of rpm and torque available when the shaft 8 of the diesel fuel injection pump 7 is at the position A in FIG. 3; the line denoted by B in FIG. 4 shows the various combinations of engine torque and engine rpm available when the shaft 8 of the diesel fuel injection pump 7 is at the position B in FIG. 3; and the line denoted by C in FIG. 4, similarly, shows the various possible combinations of engine torque and engine rpm available when the shaft 8 of the diesel fuel injection pump 7 is at the position C in FIG. 3, which is the full load position. As shown in FIG. 4, in the high load area I, which is located between the lines A and C, the flapper valve 18 of the exhaust gas recirculation valve 4 is in its fully closed position I, and exhaust gas recirculation is not performed. Further, in the area II of middle load, which is between the lines A and B, the flapper valve 18 of the exhaust gas recirculation control valve 4 is in its position II, wherein exhaust gas recirculation is performed to a moderate degree. Moreover, in the low load area III, which is the area below the line B in FIG. 4, the flapper valve 18 of the exhaust gas recirculation valve 4 is in its position III, and exhaust gas recirculation is performed at the maximum level.
This performance is more clearly shown in FIG. 5, which is a graph, drawn for a representative fixed value of engine revolution speed, in which exhaust gas recirculation ratio is the ordinate, and engine torque is the abscissa, and in which the line designated by D is a line which shows the limit for effective exhaust gas recirculation. That is, if exhaust gas recirculation is performed at a higher amount, which is above the line D in FIG. 5, sufficient oxygen is not available for combustion of the fuel injected into the cylinders of the engine, and, problems arise with regard to the emission of HC, CO, and various other unburnt hydrocarbons, such as soot. Therefore, in order to maintain proper and ideal operation of the engine, the ideal amount of exhaust gas recirculation to be provided is shown by the line D in FIG. 5.
Therefore, this line D shows the ideal amount of exhaust gas recirculation for a particular combination of engine load and engine rpm. However, in practice, to arrange for an exhaust gas recirculation control means to provide exactly this amount of exhaust gas recirculation is, as explained above, excessively costly, and is prone to operational difficulties. Therefore, according to the present invention, exhaust gas recirculation is provided according to a characteristic shown by the line denoted by E in FIG. 5, as an approximation to the ideal performance of exhaust gas recirculation. The approximation provided by this line E is so arranged that it definitely never rises above the line D. This is so as definitely to eliminate the possibility of excessive production of HC, CO, and unburnt hydrocarbons such as soot in the exhaust gases of the diesel engine. At the same time, in view of the fact that the amount of exhaust gas recirculation provided by the exhaust gas recirculation control system of the present invention, according to the line E in FIG. 5, is substantially close to the line D, the reduction of emission of NOx by the device of the present invention is, substantially, acceptable. The three stages denoted by I, II, and III denote the three positions available for the flapper valve 18, as explained above with reference to FIG. 4. In the example shown in FIG. 5, the exhaust gas recirculation ratio in the fully closed position I is approximately 0%; the exhaust gas recirculation ratio provided in the part open position II is approximately 25%; and the exhaust gas recirculation ratio provided in the full open position III is approximately 50%.
In the shown embodiment, it is possible to adjust together the part open position II of the flapper valve 18 and the full open position III of the flapper valve 18, by adjusting the effective length of the connecting rod 20, by the operation of the length adjusting means 72, as explained above. Further, the full open position III of the flapper valve 18 can be altered independently of the part open position II of the flapper valve 18, by adjusting the position of the second stopper 38, by the use of the screw 39, as also explained above.
In FIG. 6, a second embodiment of the exhaust gas recirculation control device according to the present invention is shown, in partial section. In this second embodiment, a disc-valve-and-seat-type exhaust gas recirculation control valve is used, instead of the flapper-type exhaust gas recirculation valve used in the first embodiment. In more detail, the exhaust gas recirculation control valve 4 is provided with a disc valve 18', which by its movement upwards and downwards in the figure opens and closes an exhaust gas recirculation control port 14', which is formed at the end of the elbow pipe 15'. This disc valve 18' is directly connected, via the rod 31', to the multi-action diaphragm activated control device 21, with sealing being performed by a seal member 71. Thus, the disc valve 18' is directly moved by the multi-action diaphragm activated control device 21.
The other illustrated parts in this embodiment correspond, respectively, to the parts of the first embodiment which are designated by the same reference numbers. Further, the parts of this second embodiment which are not shown are similar to those in the first embodiment.
The operation of this second embodiment is similar to the operation of the first embodiment. That is to say, when both the first inlet port 43 and the second inlet port 44 of the multi-action diaphragm activated control device 21 are supplied, not with vacuum, but with atmospheric pressure, then the disc valve 18' is in its lower position, as shown in FIG. 6, in which it fully closes the exhaust gas recirculation control port 14'. As explained above, according to the operation of the multi-action diaphragm activated control device 21 and the electrical switching system 64, this is the case when the engine load is higher than a first predetermined value. Further, when the first inlet port 43 is provided with a vacuum higher than a predetermined value, and the second inlet port 44 is not provided with vacuum, but is provided with atmospheric pressure, then the disc valve 18' rises in FIG. 6 to a certain extent, by a predetermined amount, so that the exhaust gas recirculation control port 14' is partly opened. In this position, an intermediate amount of exhaust gas recirculation is provided. This is the case, as explained above, according to the operation of the multi-action diaphragm operated control device 21 and the electrical switching means 64, when the load on the engine is lower than the second predetermined value, in other words, when the engine is operating in the low load region.
Thus, it is seen that the operation of this second embodiment is essentially similar to the operation of the first embodiment. However, it should be particularly noted that, in this second embodiment, the feature, which was present in the first embodiment, of the inlet duct 12 being somewhat restricted with regard to the flow of inlet air when the exhaust gas recirculation control valve 18 was in its fully open position III, is not present. Thus, in this second embodiment, the maximum amount of exhaust gas recirculation available does not provide such a high exhaust gas recirculation ratio as it would in the first embodiment. However, in view of other particular considerations, the second embodiment may be more applicable to certain situations. Further, it is also possible to obtain the effect of restricting the flow of inlet air, when the exhaust gas recirculation port is widely opened, by employing the disc-valve-and-seat-type valve, if the valve is so arranged that the valve element projects into the air inlet passage when it opens the exhaust gas recirculation port.
In various other possible embodiments, the electrical switching system 64 could be arranged differently. For example, this electrical switching system 64 might provide a three-way electrical control signal according to the varying position of a control rack which was provided to an in-line type diesel fuel injection pump. Alternatively, the electrical switching system 64 might provide its three-way signal according to the movement of the spill ring of a distributor type diesel fuel injection pump. In these cases, the control of exhaust gas recirculation can be done more precisely with reference to the engine load, because the switching action of the electrical switching device 64 can be performed without any influence from the characteristics of the governor of the fuel injection pump.
Although in the present embodiment the electrical switching device 64 produces an electric signal which is, effectively, a three-way electric signal (considering the combination of the two electric signals carried by the two wires which lead from the two contact arms 69 and 70 to the two coils 53 and 58 as a single three-way electrical control signal), this three-way electrical control signal might be provided in a different form. Analogously, although the control signals which are provided to the multi-action diaphragm actuated control device 21, which are fluid pressure signals, are in the shown embodiment provided as two independent fluid pressure signals, this is not essential, and it is only essential that a three-way fluid pressure signal should be provided to the multi-action diaphragm actuated control device 21; this three-way fluid pressure signal might take on a variety of forms, not being restricted merely to the pair of two-way fluid pressure signals, as in the shown embodiments.
Although the present invention has been shown and described in terms of several preferred embodiments thereof, and in language more or less specific with regard to structural features thereof, and with reference to the illustrative drawings, it should be understood that in any particular embodiment of the present invention various changes, modifications, and omissions of the form and the content of the present invention can be made by a person skilled in the art, without departing from its essential scope. Therefore, it is expressly desired that the scope of the present invention should be uniquely delimited by the legitimate and valid scope of the appended claims, which follow, and not by any of the perhaps purely fortuitous details of the shown embodiments, or of the drawings. | An exhaust gas recirculation control system for particular application to a diesel engine, which has an exhaust gas recirculation control valve, and a means for actuating the exhaust gas recirculation control valve, which positions the exhaust gas recirculation control valve selectively and steppedly at one of three states, that are: a first state in which it provides substantially zero exhaust gas recirculation ratio, a second state in which it provides a medium exhaust gas recirculation ratio, and a third state in which it provides a maximum exhaust gas recirculation ratio, according to the load on the engine, so that the valve is steppedly shifted from the third state toward the first state via the second state as engine load increases. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to motor vehicle safety devices and specifically to a practical and reliable device which responds to indications of driver fatigue by sounding an alarm.
Driver fatigue, resulting in inattention and falling asleep at the wheel, is considered responsible for many highway accidents. Early signs of fatigue include staring blankly at the road ahead and a reduction in the rate of blinking as drivers struggle to keep their eyes open; a condition sometimes known as "highway hypnosis". Drivers of motor vehicles, particularly on long highway drives, are frequently stricken by fatigue and need to stop and rest in order to return to an alert condition before continuing. The driver, however, may be miles from a safe area in which to stop and is therefore required to continue driving. It is therefore a primary object of the present invention to provide an aid for motor vehicle operators to maintain a condition of alertness until a safe rest area is available.
Prior art in the area of awakening alarms for drivers has included devices to sense such indications of sleep as nodding of the head or erratic steering wheel movements. Devices depending on such indications have been found to trigger an alarm too late to be of use in preventing accidents.
Devices intended to be installed as part of a vehicle and to operate at a distance from the driver are necessarily complex and expensive. Further, such devises are likely to be available only in new vehicles, so not for use by the general public in the near future.
Prior art inventions using glasses as part of a system to detect a sleeping driver and to provide an awakening alarm have, in general, attempted to use the closing of the eyes to activate an alarm signal. Such devises sometimes include a timer to provide a delay period between the closing of the eyes and the activation of the alarm and can be thought of as having a positively triggered alarm since the timing cycle begins when the eyes are closed. The present invention differs from prior art in that blinking and eye motion, which are characteristic of an alert driver, are used to continually delay the activation of an alarm signal. Advantages of the system of the present invention will be seen in the following specifications.
Certain prior inventions have proposed using the eyelash or eyelid when the eye is closed to interrupt a beam between a light source and light sensor, thereby triggering an alarm. A break-beam device such as U.S. Pat. No. 5,402,109 to Mannick (1995) requires elaborate means to maintain an uncommonly precise relation of a source and sensor to the eye, making the glasses of this device inconvenient to use and uncomfortable to wear.
A device such as U.S. Pat. No. 5,469,143 to Cooper (1995) which has an element in physical contact with the eyelid has an additional disadvantage in the discomfort that is experienced when anything touches the sensitive area surrounding the eye.
To use the difference in the amount of light reflected by the open eye and by the eyelid to positively trigger an alarm signal when the eye is closed requires a complex electronic circuit to eliminate the effect of changes in ambient light or changes which occur when the head is moved. Further, since different areas of an open eye reflect light differently, certain kinds of eye movement may cause false alarms. Further still, a positively triggered alarm relying on a change in the amount of light received by a sensor while compensating for changes in ambient light will require a relatively sudden closing of the eye to function properly and may not trigger an alarm in response to drooping eyelids and the gradual closing of the eye.
A further disadvantage of all such prior art devices which rely entirely on the closing of an eye to trigger an alarm is that closed eyes indicate the condition of sleep and that the driver has already lost attention and control. The alarm, then, may be triggered too late to prevent an accident.
OBJECTS OF THE INVENTION
Accordingly, an object of the invention is to provide an awakening alarm which is reliable and capable of responding to early signs of driver fatigue.
Another object of the invention is to provide an awakening alarm which is easy to use and comfortable to wear.
Another object of the invention is to provide an awakening alarm which is simple and inexpensive.
Another object of the invention is to provide an awakening alarm which is portable and may be used in any vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an electronic circuit according to the preferred embodiment.
FIG. 2 is a schematic diagram of an abbreviated circuit.
FIG. 3 is a rear view showing details for construction of eyewear according to the present invention.
FIG.4 is an exploded view of light sensor and shield in relation to nose-pad section of glasses.
FIG.5 shows glasses worn with circuit enclosure.
SUMMARY OF THE INVENTION
The present invention comprises eyewear in the form of glasses as a convenient means of holding a light sensor in position to receive light reflected from an eye and to be affected by a difference in reflectivity of the eyelid and the surface of the open eye. This sensor provides input to an electronic circuit wherein an integrated circuit comparator uses variations in voltage which occur during blinking and certain kinds of eyemovement to produce pulses which reset an electronic timing cycle, thereby delaying the activation of an alarm signal. Drooping eyelids, staring without blinking and closed eyes are conditions which produce a steady input state through the sensor and which will allow the timing cycle to becompleted, activating an alarm. In this way the present invention is able to respond both to signs of sleep and to early signs of fatigue. In a preferred embodiment a two-stage timing cycle is provided so that a muted warning tone may first be sounded as a reminder to the wearer of the glasses either to open the eyes or to blink and shift the point of vision.A full alarm is sounded at the completion of a second short-duration timingcycle if the wearer of the glasses fails to respond to the warning tone. This feature makes an alarm of this type less objectionable to use, therefore more likely to be used to encourage frequent eye movement; an often cited counter-measure against the effects of fatigue.
Overcoming prior art disadvantages, the present invention provides a simpleelectronic circuit which uses ambient light except in low-light or night conditions when an infrared source is required for illumination. Change inthe amount of ambient light and changes which occur when the head is moved have little effect on the functioning of the present invention. Further, since an alarm is triggered by a reliable timing device in response to an absence of blinking or eye movement, false alarms and missed alarms are effectively eliminated. The ability of the circuit of the present invention to use reflected light also allows the location of both a sensorand an infrared source in the center, nose-pad area of a pair of glasses, providing for unrestricted vision and permitting some shifting of the glasses on the face to occur while maintaining the necessary alignment of sensor to the eye.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG.1 shows a schematic diagram of an electronic circuit according to the preferred embodiment. The circuit shown is based upon a multiple comparator integrated circuit such as the 339 series comparator, chosen for the characteristics of operation over a wide voltage range and single polarity power supply requirements. Combinations of other components, however, which function in essentially the same way and with the same result should be considered as within the scope of the present invention. Light sensor 1 is positioned and shielded to receive light which is reflected from an eye and provides input for the following circuit. Comparator 2 is shown used in a feedback loop circuit and functions as a voltage amplifier. The primary function of this stage is to supply sufficient current to charge capacitor 3. Typically, when a silicon phototransistor as shown provides input, the output of comparator 2 may follow input voltage or provide low-gain amplification if necessary. Comparator 4 is used in open loop mode. When voltage at the inverting input exceeds voltage at the non-inverting input, the output of comparator4 will switch to ground.
The values of resistor 5 and capacitor 6 define the duration of a timing cycle for a 555 or similar type timer integrated circuit 7. Beginning operation, capacitor 6 is being charged through resistor 5. If the charge on capacitor 6 is allowed to reach the threshold voltage of timer 7 the output of this timer will switch to ground, activating alarm signal 8. In the preferred embodiment a second timer 9 may be used in cascaded relationto timer 7 such that when signal 8 is activated to a muted warning tone through resistor 10, NPN transistor 11 is simultaneously made non-conductive, beginning a short-duration timing cycle defined by the values of resistor 12 and capacitor 13, after which alarm signal 8 will beactivated to full output.
In the act of blinking, the eye is first closed and light sensor 1 is exposed to an increased intensity of light from the generally more reflective eyelid. Current through sensor 1 increases and capacitor 3 is charged to a higher voltage level through diode 14. Completing the act of blinking, the eye is reopened and light sensor 1 is exposed to a decreasedintensity of light from the less reflective surface of the eye. Voltage at the non-inverting input to comparator 4 decreases while the charge on capacitor 3 and, therefore, voltage at the inverting input to comparator 4remains at a higher level for a period of time dependent on the values of capacitor 3 and resistor 15. Upon the opening of the eye, then, voltage atthe inverting input is made to exceed voltage at the non-inverting input and the output of comparator 4 switches to ground, discharging capacitor 6; thereby resetting the timing cycle of timer 7. At the same time a trigger pulse is delivered to both timers, allowing a new timing cycle to begin when the output of comparator 4 switches from ground due to discharge of capacitor 3 through resistor 15.
The act of looking down, as when a driver checks the speedometer, followed by returning vision to the road, will have the same effect as blinking. Further, when a light sensor is positioned as shown in the drawings, shifting the eyes to the left, as when checking the drivers outside rearview mirror, will bring the light absorbing pupil of the eye into the area monitored by the sensor and may serve to further delay the sounding of an alarm. In this way an alarm may be continually delayed only by the frequent eye movement of an alert driver, while absence of eye movement, indicating sleep or fatigue, will allow the alarm of the present inventionto be activated. For the task of driving a motor vehicle the duration of the initial timing cycle should be in the range of a few seconds. By providing a longer initial timing cycle, however, the device of the present invention can be made more useful for tasks which require that a user stay awake for a period of time but which do not require the moment by moment attention of driving. Such tasks might include piloting of aircraft or watercraft and security watches.
Comparators 16 and 17 are shown used in a system allowing the present invention to operate under the widely varying lighting conditions encountered by a motor vehicle operator.
Operating from input provided by a light sensor 18, positioned so as to be affected only by changes in ambient light, comparator 16 is adjustable by means of variable resistor 19 to activate infrared-emitting diode 20 when the light level falls below circuit requirements. Comparator 17 is adjustable by means of variable resistor 21 to reduce input balance resistance under the extreme lighting condition encountered when driving into a morning or evening sun. Comparators may be used in a similar way tocontrol current through infrared-emitting diode 20 or to modify amplifier gain. By the addition of comparators a further multiplicity of overlappingranges can be provided if desired.
FIG.2 shows an abbreviated circuit according to the present invention whichwill sound an alarm when the eyes are closed for a period of time longer than that which is required for blinking. The values of capacitor 3 and resistor 15 are chosen to allow at least several seconds after blinking before the output of comparator 4 switches to positive voltage due to current flow through resistor 15. The circuit of capacitor 3 and resistor 15, then, functions as a timer. Resistor 22 and capacitor 23 provide a delay long enough to allow blinking to occur without sounding alarm signal8. Comparator 17 is shown having an input circuit which functions the same as that for comparator 4. Values of resistor 24 and capacitor 25 are chosen to provide a momentary short of capacitor 3 to ground when a sharp decrease in light intensity is experienced at sensor 18 such as would occur immediately after the lights from an oncoming vehicle have shone in the eyes of a driver, since such an occurrence might otherwise temporarilydisable the alarm. Since a circuit of the type shown in FIG.2 will more closely monitor the open or closed condition of the eye, an emergency modeof operation could be so provided for a circuit according to the preferred embodiment, selectable by means of a two-position switch, if a driver feels in immediate danger of falling asleep.
FIG.3 shows one method for constructing eyewear according to the present invention. Glasses of a type made of molded plastic and having hinged, molded ear-pieces 26 and integral, molded nose-pads 27 hold shielded lightsensor 1 and infrared diode 20. A conduit 28 for electrical leads 29 extends along the upper edge of the glasses to a flexible conduit 30 running through and held by ear-piece 26. An opaque front cover 31 provides clearance for electrical leads and connections to light sensor 1 and infrared diode 20. One possible location for alarm signal 8, shown here as a piezo buzzer element, is mounted to ear-piece 26. Alternately, if a signaling means is provided in the form of an earphone of the type which can be worn in the ear, a strong alarm tone can easily be provided which is audible only to the wearer of the glasses.
FIG.4 illustrates, in exploded view, the relation of nose-pad 27 to a hole 32, angled to hold light sensor 1 and tubular light shield 33 directed toward a wearer's right eye. Location of a sensor in this area of a pair of glasses allows close proximity of the sensor to the eye yet provides anun-diminished field of vision. Alternately, light guides or fiber-optic material could be used to facilitate the location of a sensor or infrared source in another area of a pair of glasses according to the present invention. A feature allowing the distance between separate nose-pads extending from glasses to be widened or narrowed, such as is commonly incorporated into many designs for eyewear, would permit the height of theglasses upon the nose to be adjusted for individual users of the present invention; thus providing for optimum positioning of a sensor at or somewhat below the vertical center of the eye. Certain very sensitive photo-electrical devises may require the use of a light-reducing aperture or filter element 34 to assure that the device operates below the level ofelectrical saturation.
In FIG.5 covered electrical leads 30 are shown extending to an enclosure 35for an electronic circuit according to the present invention made with currently standard size components and including a battery power supply and a power switch 36. A neck-strap 37 is shown as one means of supportingenclosure 35. The use of currently available miniature electronic components would offer the advantage of reduced circuit size and weight and the possibility of including a circuit within the frame area of eyewear according to the present invention, eliminating the need for a separate circuit enclosure.
Although one method for constructing glasses has been detailed in the drawings, many modifications are possible in construction. Provision of suitable electrical contacts to the contacting surfaces of the frame section of glasses and the hinged ear-pieces such that electrical contact is made when the glasses are unfolded would allow continuation of electrical leads when the glasses are worn while allowing glasses to be folded without the bending of conductors. Designs providing for interchangeable lenses for day or night-time use or allowing prescription lenses to be used would further the usefulness of the present invention. The use of photochromic material in lenses could provide a degree of passive control of the amount of light reaching the sensor, while the use of liquid crystal material in a filter element could provide further electronic control of light. Electrical leads within the glasses could be provided in the form of conductive material printed on or incorporated into the material of the glasses during manufacture. By using timer outputto activate relays, a powerful remote alarm could be controlled; perhaps most useful if an embodiment of the present invention were powered from a cigarette lighter outlet. Therefore, it should be understood from the preceding specifications and drawings that variations in construction and use are possible within the spirit and scope of the present invention according to the appended claims. | Eyeglasses hold a light sensor (1) positioned to receive light reflected from an eye. An electronic comparator circuit (4) uses variations of current through the sensor which occur during blinking and eye movement to produce pulses which reset an electronic timing cycle, thereby continually delaying the activation of an alarm signal (8). In the absence of eye motion for a predetermined period of time a warning tone is sounded in the preferred embodiment, followed by a full volume alarm if needed to wake a sleeping driver. | 6 |
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